sys/dev/hwpmc/hwpmc_mod.c

   1 /*-
   2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
   3  *
   4  * Copyright (c) 2003-2008 Joseph Koshy
   5  * Copyright (c) 2007 The FreeBSD Foundation
   6  * Copyright (c) 2018 Matthew Macy
   7  * All rights reserved.
   8  *
   9  * Portions of this software were developed by A. Joseph Koshy under
  10  * sponsorship from the FreeBSD Foundation and Google, Inc.
  11  *
  12  * Redistribution and use in source and binary forms, with or without
  13  * modification, are permitted provided that the following conditions
  14  * are met:
  15  * 1. Redistributions of source code must retain the above copyright
  16  *    notice, this list of conditions and the following disclaimer.
  17  * 2. Redistributions in binary form must reproduce the above copyright
  18  *    notice, this list of conditions and the following disclaimer in the
  19  *    documentation and/or other materials provided with the distribution.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  *
  33  */
  34
  35 #include <sys/cdefs.h>
  36 __FBSDID("$FreeBSD$");
  37
  38 #include <sys/param.h>
  39 #include <sys/eventhandler.h>
  40 #include <sys/gtaskqueue.h>
  41 #include <sys/jail.h>
  42 #include <sys/kernel.h>
  43 #include <sys/kthread.h>
  44 #include <sys/limits.h>
  45 #include <sys/lock.h>
  46 #include <sys/malloc.h>
  47 #include <sys/module.h>
  48 #include <sys/mount.h>
  49 #include <sys/mutex.h>
  50 #include <sys/pmc.h>
  51 #include <sys/pmckern.h>
  52 #include <sys/pmclog.h>
  53 #include <sys/priv.h>
  54 #include <sys/proc.h>
  55 #include <sys/queue.h>
  56 #include <sys/resourcevar.h>
  57 #include <sys/rwlock.h>
  58 #include <sys/sched.h>
  59 #include <sys/signalvar.h>
  60 #include <sys/smp.h>
  61 #include <sys/sx.h>
  62 #include <sys/sysctl.h>
  63 #include <sys/sysent.h>
  64 #include <sys/systm.h>
  65 #include <sys/vnode.h>
  66
  67 #include <sys/linker.h>         /* needs to be after <sys/malloc.h> */
  68
  69 #include <machine/atomic.h>
  70 #include <machine/md_var.h>
  71
  72 #include <vm/vm.h>
  73 #include <vm/vm_extern.h>
  74 #include <vm/pmap.h>
  75 #include <vm/vm_map.h>
  76 #include <vm/vm_object.h>
  77
  78 #include "hwpmc_soft.h"
  79
  80 #ifdef NUMA
  81 #define NDOMAINS vm_ndomains
  82 #else
  83 #define NDOMAINS 1
  84 #define malloc_domain(size, type, domain, flags) malloc((size), (type), (flags))
  85 #define free_domain(addr, type) free(addr, type)
  86 #endif
  87
  88 /*
  89  * Types
  90  */
  91
  92 enum pmc_flags {
  93         PMC_FLAG_NONE     = 0x00, /* do nothing */
  94         PMC_FLAG_REMOVE   = 0x01, /* atomically remove entry from hash */
  95         PMC_FLAG_ALLOCATE = 0x02, /* add entry to hash if not found */
  96         PMC_FLAG_NOWAIT   = 0x04, /* do not wait for mallocs */
  97 };
  98
  99 /*
 100  * The offset in sysent where the syscall is allocated.
 101  */
 102
 103 static int pmc_syscall_num = NO_SYSCALL;
 104 struct pmc_cpu          **pmc_pcpu;      /* per-cpu state */
 105 pmc_value_t             *pmc_pcpu_saved; /* saved PMC values: CSW handling */
 106
 107 #define PMC_PCPU_SAVED(C,R)     pmc_pcpu_saved[(R) + md->pmd_npmc*(C)]
 108
 109 struct mtx_pool         *pmc_mtxpool;
 110 static int              *pmc_pmcdisp;    /* PMC row dispositions */
 111
 112 #define PMC_ROW_DISP_IS_FREE(R)         (pmc_pmcdisp[(R)] == 0)
 113 #define PMC_ROW_DISP_IS_THREAD(R)       (pmc_pmcdisp[(R)] > 0)
 114 #define PMC_ROW_DISP_IS_STANDALONE(R)   (pmc_pmcdisp[(R)] < 0)
 115
 116 #define PMC_MARK_ROW_FREE(R) do {                                         \
 117         pmc_pmcdisp[(R)] = 0;                                             \
 118 } while (0)
 119
 120 #define PMC_MARK_ROW_STANDALONE(R) do {                                   \
 121         KASSERT(pmc_pmcdisp[(R)] <= 0, ("[pmc,%d] row disposition error", \
 122                     __LINE__));                                           \
 123         atomic_add_int(&pmc_pmcdisp[(R)], -1);                            \
 124         KASSERT(pmc_pmcdisp[(R)] >= (-pmc_cpu_max_active()),              \
 125                 ("[pmc,%d] row disposition error", __LINE__));            \
 126 } while (0)
 127
 128 #define PMC_UNMARK_ROW_STANDALONE(R) do {                                 \
 129         atomic_add_int(&pmc_pmcdisp[(R)], 1);                             \
 130         KASSERT(pmc_pmcdisp[(R)] <= 0, ("[pmc,%d] row disposition error", \
 131                     __LINE__));                                           \
 132 } while (0)
 133
 134 #define PMC_MARK_ROW_THREAD(R) do {                                       \
 135         KASSERT(pmc_pmcdisp[(R)] >= 0, ("[pmc,%d] row disposition error", \
 136                     __LINE__));                                           \
 137         atomic_add_int(&pmc_pmcdisp[(R)], 1);                             \
 138 } while (0)
 139
 140 #define PMC_UNMARK_ROW_THREAD(R) do {                                     \
 141         atomic_add_int(&pmc_pmcdisp[(R)], -1);                            \
 142         KASSERT(pmc_pmcdisp[(R)] >= 0, ("[pmc,%d] row disposition error", \
 143                     __LINE__));                                           \
 144 } while (0)
 145
 146
 147 /* various event handlers */
 148 static eventhandler_tag pmc_exit_tag, pmc_fork_tag, pmc_kld_load_tag,
 149     pmc_kld_unload_tag;
 150
 151 /* Module statistics */
 152 struct pmc_driverstats pmc_stats;
 153
 154
 155 /* Machine/processor dependent operations */
 156 static struct pmc_mdep  *md;
 157
 158 /*
 159  * Hash tables mapping owner processes and target threads to PMCs.
 160  */
 161
 162 struct mtx pmc_processhash_mtx;         /* spin mutex */
 163 static u_long pmc_processhashmask;
 164 static LIST_HEAD(pmc_processhash, pmc_process)  *pmc_processhash;
 165
 166 /*
 167  * Hash table of PMC owner descriptors.  This table is protected by
 168  * the shared PMC "sx" lock.
 169  */
 170
 171 static u_long pmc_ownerhashmask;
 172 static LIST_HEAD(pmc_ownerhash, pmc_owner)      *pmc_ownerhash;
 173
 174 /*
 175  * List of PMC owners with system-wide sampling PMCs.
 176  */
 177
 178 static CK_LIST_HEAD(, pmc_owner)                        pmc_ss_owners;
 179
 180 /*
 181  * List of free thread entries. This is protected by the spin
 182  * mutex.
 183  */
 184 static struct mtx pmc_threadfreelist_mtx;       /* spin mutex */
 185 static LIST_HEAD(, pmc_thread)                  pmc_threadfreelist;
 186 static int pmc_threadfreelist_entries=0;
 187 #define THREADENTRY_SIZE                                                \
 188 (sizeof(struct pmc_thread) + (md->pmd_npmc * sizeof(struct pmc_threadpmcstate)))
 189
 190 /*
 191  * Task to free thread descriptors
 192  */
 193 static struct grouptask free_gtask;
 194
 195 /*
 196  * A map of row indices to classdep structures.
 197  */
 198 static struct pmc_classdep **pmc_rowindex_to_classdep;
 199
 200 /*
 201  * Prototypes
 202  */
 203
 204 #ifdef  HWPMC_DEBUG
 205 static int      pmc_debugflags_sysctl_handler(SYSCTL_HANDLER_ARGS);
 206 static int      pmc_debugflags_parse(char *newstr, char *fence);
 207 #endif
 208
 209 static int      load(struct module *module, int cmd, void *arg);
 210 static void     pmc_add_thread_descriptors_from_proc(struct proc *p,
 211     struct pmc_process *pp);
 212 static int      pmc_attach_process(struct proc *p, struct pmc *pm);
 213 static struct pmc *pmc_allocate_pmc_descriptor(void);
 214 static struct pmc_owner *pmc_allocate_owner_descriptor(struct proc *p);
 215 static int      pmc_attach_one_process(struct proc *p, struct pmc *pm);
 216 static int      pmc_can_allocate_rowindex(struct proc *p, unsigned int ri,
 217     int cpu);
 218 static int      pmc_can_attach(struct pmc *pm, struct proc *p);
 219 static void     pmc_capture_user_callchain(int cpu, int soft, struct trapframe *tf);
 220 static void     pmc_cleanup(void);
 221 static int      pmc_detach_process(struct proc *p, struct pmc *pm);
 222 static int      pmc_detach_one_process(struct proc *p, struct pmc *pm,
 223     int flags);
 224 static void     pmc_destroy_owner_descriptor(struct pmc_owner *po);
 225 static void     pmc_destroy_pmc_descriptor(struct pmc *pm);
 226 static void     pmc_destroy_process_descriptor(struct pmc_process *pp);
 227 static struct pmc_owner *pmc_find_owner_descriptor(struct proc *p);
 228 static int      pmc_find_pmc(pmc_id_t pmcid, struct pmc **pm);
 229 static struct pmc *pmc_find_pmc_descriptor_in_process(struct pmc_owner *po,
 230     pmc_id_t pmc);
 231 static struct pmc_process *pmc_find_process_descriptor(struct proc *p,
 232     uint32_t mode);
 233 static struct pmc_thread *pmc_find_thread_descriptor(struct pmc_process *pp,
 234     struct thread *td, uint32_t mode);
 235 static void     pmc_force_context_switch(void);
 236 static void     pmc_link_target_process(struct pmc *pm,
 237     struct pmc_process *pp);
 238 static void     pmc_log_all_process_mappings(struct pmc_owner *po);
 239 static void     pmc_log_kernel_mappings(struct pmc *pm);
 240 static void     pmc_log_process_mappings(struct pmc_owner *po, struct proc *p);
 241 static void     pmc_maybe_remove_owner(struct pmc_owner *po);
 242 static void     pmc_process_csw_in(struct thread *td);
 243 static void     pmc_process_csw_out(struct thread *td);
 244 static void     pmc_process_exit(void *arg, struct proc *p);
 245 static void     pmc_process_fork(void *arg, struct proc *p1,
 246     struct proc *p2, int n);
 247 static void     pmc_process_samples(int cpu, int soft);
 248 static void     pmc_release_pmc_descriptor(struct pmc *pmc);
 249 static void     pmc_process_thread_add(struct thread *td);
 250 static void     pmc_process_thread_delete(struct thread *td);
 251 static void     pmc_remove_owner(struct pmc_owner *po);
 252 static void     pmc_remove_process_descriptor(struct pmc_process *pp);
 253 static void     pmc_restore_cpu_binding(struct pmc_binding *pb);
 254 static void     pmc_save_cpu_binding(struct pmc_binding *pb);
 255 static void     pmc_select_cpu(int cpu);
 256 static int      pmc_start(struct pmc *pm);
 257 static int      pmc_stop(struct pmc *pm);
 258 static int      pmc_syscall_handler(struct thread *td, void *syscall_args);
 259 static struct pmc_thread *pmc_thread_descriptor_pool_alloc(void);
 260 static void     pmc_thread_descriptor_pool_drain(void);
 261 static void     pmc_thread_descriptor_pool_free(struct pmc_thread *pt);
 262 static void     pmc_unlink_target_process(struct pmc *pmc,
 263     struct pmc_process *pp);
 264 static int generic_switch_in(struct pmc_cpu *pc, struct pmc_process *pp);
 265 static int generic_switch_out(struct pmc_cpu *pc, struct pmc_process *pp);
 266 static struct pmc_mdep *pmc_generic_cpu_initialize(void);
 267 static void pmc_generic_cpu_finalize(struct pmc_mdep *md);
 268
 269 /*
 270  * Kernel tunables and sysctl(8) interface.
 271  */
 272
 273 SYSCTL_DECL(_kern_hwpmc);
 274 SYSCTL_NODE(_kern_hwpmc, OID_AUTO, stats, CTLFLAG_RW, 0, "HWPMC stats");
 275
 276
 277 /* Stats. */
 278 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, intr_ignored, CTLFLAG_RW,
 279                                    &pmc_stats.pm_intr_ignored, "# of interrupts ignored");
 280 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, intr_processed, CTLFLAG_RW,
 281                                    &pmc_stats.pm_intr_processed, "# of interrupts processed");
 282 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, intr_bufferfull, CTLFLAG_RW,
 283                                    &pmc_stats.pm_intr_bufferfull, "# of interrupts where buffer was full");
 284 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, syscalls, CTLFLAG_RW,
 285                                    &pmc_stats.pm_syscalls, "# of syscalls");
 286 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, syscall_errors, CTLFLAG_RW,
 287                                    &pmc_stats.pm_syscall_errors, "# of syscall_errors");
 288 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, buffer_requests, CTLFLAG_RW,
 289                                    &pmc_stats.pm_buffer_requests, "# of buffer requests");
 290 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, buffer_requests_failed, CTLFLAG_RW,
 291                                    &pmc_stats.pm_buffer_requests_failed, "# of buffer requests which failed");
 292 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, log_sweeps, CTLFLAG_RW,
 293                                    &pmc_stats.pm_log_sweeps, "# of ?");
 294
 295 static int pmc_callchaindepth = PMC_CALLCHAIN_DEPTH;
 296 SYSCTL_INT(_kern_hwpmc, OID_AUTO, callchaindepth, CTLFLAG_RDTUN,
 297     &pmc_callchaindepth, 0, "depth of call chain records");
 298
 299 char pmc_cpuid[64];
 300 SYSCTL_STRING(_kern_hwpmc, OID_AUTO, cpuid, CTLFLAG_RD,
 301         pmc_cpuid, 0, "cpu version string");
 302 #ifdef  HWPMC_DEBUG
 303 struct pmc_debugflags pmc_debugflags = PMC_DEBUG_DEFAULT_FLAGS;
 304 char    pmc_debugstr[PMC_DEBUG_STRSIZE];
 305 TUNABLE_STR(PMC_SYSCTL_NAME_PREFIX "debugflags", pmc_debugstr,
 306     sizeof(pmc_debugstr));
 307 SYSCTL_PROC(_kern_hwpmc, OID_AUTO, debugflags,
 308     CTLTYPE_STRING | CTLFLAG_RWTUN | CTLFLAG_NOFETCH,
 309     0, 0, pmc_debugflags_sysctl_handler, "A", "debug flags");
 310 #endif
 311
 312
 313 /*
 314  * kern.hwpmc.hashrows -- determines the number of rows in the
 315  * of the hash table used to look up threads
 316  */
 317
 318 static int pmc_hashsize = PMC_HASH_SIZE;
 319 SYSCTL_INT(_kern_hwpmc, OID_AUTO, hashsize, CTLFLAG_RDTUN,
 320     &pmc_hashsize, 0, "rows in hash tables");
 321
 322 /*
 323  * kern.hwpmc.nsamples --- number of PC samples/callchain stacks per CPU
 324  */
 325
 326 static int pmc_nsamples = PMC_NSAMPLES;
 327 SYSCTL_INT(_kern_hwpmc, OID_AUTO, nsamples, CTLFLAG_RDTUN,
 328     &pmc_nsamples, 0, "number of PC samples per CPU");
 329
 330
 331 /*
 332  * kern.hwpmc.mtxpoolsize -- number of mutexes in the mutex pool.
 333  */
 334
 335 static int pmc_mtxpool_size = PMC_MTXPOOL_SIZE;
 336 SYSCTL_INT(_kern_hwpmc, OID_AUTO, mtxpoolsize, CTLFLAG_RDTUN,
 337     &pmc_mtxpool_size, 0, "size of spin mutex pool");
 338
 339
 340 /*
 341  * kern.hwpmc.threadfreelist_entries -- number of free entries
 342  */
 343
 344 SYSCTL_INT(_kern_hwpmc, OID_AUTO, threadfreelist_entries, CTLFLAG_RD,
 345     &pmc_threadfreelist_entries, 0, "number of avalable thread entries");
 346
 347
 348 /*
 349  * kern.hwpmc.threadfreelist_max -- maximum number of free entries
 350  */
 351
 352 static int pmc_threadfreelist_max = PMC_THREADLIST_MAX;
 353 SYSCTL_INT(_kern_hwpmc, OID_AUTO, threadfreelist_max, CTLFLAG_RW,
 354     &pmc_threadfreelist_max, 0,
 355     "maximum number of available thread entries before freeing some");
 356
 357
 358 /*
 359  * security.bsd.unprivileged_syspmcs -- allow non-root processes to
 360  * allocate system-wide PMCs.
 361  *
 362  * Allowing unprivileged processes to allocate system PMCs is convenient
 363  * if system-wide measurements need to be taken concurrently with other
 364  * per-process measurements.  This feature is turned off by default.
 365  */
 366
 367 static int pmc_unprivileged_syspmcs = 0;
 368 SYSCTL_INT(_security_bsd, OID_AUTO, unprivileged_syspmcs, CTLFLAG_RWTUN,
 369     &pmc_unprivileged_syspmcs, 0,
 370     "allow unprivileged process to allocate system PMCs");
 371
 372 /*
 373  * Hash function.  Discard the lower 2 bits of the pointer since
 374  * these are always zero for our uses.  The hash multiplier is
 375  * round((2^LONG_BIT) * ((sqrt(5)-1)/2)).
 376  */
 377
 378 #if     LONG_BIT == 64
 379 #define _PMC_HM         11400714819323198486u
 380 #elif   LONG_BIT == 32
 381 #define _PMC_HM         2654435769u
 382 #else
 383 #error  Must know the size of 'long' to compile
 384 #endif
 385
 386 #define PMC_HASH_PTR(P,M)       ((((unsigned long) (P) >> 2) * _PMC_HM) & (M))
 387
 388 /*
 389  * Syscall structures
 390  */
 391
 392 /* The `sysent' for the new syscall */
 393 static struct sysent pmc_sysent = {
 394         .sy_narg =      2,
 395         .sy_call =      pmc_syscall_handler,
 396 };
 397
 398 static struct syscall_module_data pmc_syscall_mod = {
 399         .chainevh =     load,
 400         .chainarg =     NULL,
 401         .offset =       &pmc_syscall_num,
 402         .new_sysent =   &pmc_sysent,
 403         .old_sysent =   { .sy_narg = 0, .sy_call = NULL },
 404         .flags =        SY_THR_STATIC_KLD,
 405 };
 406
 407 static moduledata_t pmc_mod = {
 408         .name =         PMC_MODULE_NAME,
 409         .evhand =       syscall_module_handler,
 410         .priv =         &pmc_syscall_mod,
 411 };
 412
 413 #ifdef EARLY_AP_STARTUP
 414 DECLARE_MODULE(pmc, pmc_mod, SI_SUB_SYSCALLS, SI_ORDER_ANY);
 415 #else
 416 DECLARE_MODULE(pmc, pmc_mod, SI_SUB_SMP, SI_ORDER_ANY);
 417 #endif
 418 MODULE_VERSION(pmc, PMC_VERSION);
 419
 420 #ifdef  HWPMC_DEBUG
 421 enum pmc_dbgparse_state {
 422         PMCDS_WS,               /* in whitespace */
 423         PMCDS_MAJOR,            /* seen a major keyword */
 424         PMCDS_MINOR
 425 };
 426
 427 static int
 428 pmc_debugflags_parse(char *newstr, char *fence)
 429 {
 430         char c, *p, *q;
 431         struct pmc_debugflags *tmpflags;
 432         int error, found, *newbits, tmp;
 433         size_t kwlen;
 434
 435         tmpflags = malloc(sizeof(*tmpflags), M_PMC, M_WAITOK|M_ZERO);
 436
 437         p = newstr;
 438         error = 0;
 439
 440         for (; p < fence && (c = *p); p++) {
 441
 442                 /* skip white space */
 443                 if (c == ' ' || c == '\t')
 444                         continue;
 445
 446                 /* look for a keyword followed by "=" */
 447                 for (q = p; p < fence && (c = *p) && c != '='; p++)
 448                         ;
 449                 if (c != '=') {
 450                         error = EINVAL;
 451                         goto done;
 452                 }
 453
 454                 kwlen = p - q;
 455                 newbits = NULL;
 456
 457                 /* lookup flag group name */
 458 #define DBG_SET_FLAG_MAJ(S,F)                                           \
 459                 if (kwlen == sizeof(S)-1 && strncmp(q, S, kwlen) == 0)  \
 460                         newbits = &tmpflags->pdb_ ## F;
 461
 462                 DBG_SET_FLAG_MAJ("cpu",         CPU);
 463                 DBG_SET_FLAG_MAJ("csw",         CSW);
 464                 DBG_SET_FLAG_MAJ("logging",     LOG);
 465                 DBG_SET_FLAG_MAJ("module",      MOD);
 466                 DBG_SET_FLAG_MAJ("md",          MDP);
 467                 DBG_SET_FLAG_MAJ("owner",       OWN);
 468                 DBG_SET_FLAG_MAJ("pmc",         PMC);
 469                 DBG_SET_FLAG_MAJ("process",     PRC);
 470                 DBG_SET_FLAG_MAJ("sampling",    SAM);
 471
 472                 if (newbits == NULL) {
 473                         error = EINVAL;
 474                         goto done;
 475                 }
 476
 477                 p++;            /* skip the '=' */
 478
 479                 /* Now parse the individual flags */
 480                 tmp = 0;
 481         newflag:
 482                 for (q = p; p < fence && (c = *p); p++)
 483                         if (c == ' ' || c == '\t' || c == ',')
 484                                 break;
 485
 486                 /* p == fence or c == ws or c == "," or c == 0 */
 487
 488                 if ((kwlen = p - q) == 0) {
 489                         *newbits = tmp;
 490                         continue;
 491                 }
 492
 493                 found = 0;
 494 #define DBG_SET_FLAG_MIN(S,F)                                           \
 495                 if (kwlen == sizeof(S)-1 && strncmp(q, S, kwlen) == 0)  \
 496                         tmp |= found = (1 << PMC_DEBUG_MIN_ ## F)
 497
 498                 /* a '*' denotes all possible flags in the group */
 499                 if (kwlen == 1 && *q == '*')
 500                         tmp = found = ~0;
 501                 /* look for individual flag names */
 502                 DBG_SET_FLAG_MIN("allocaterow", ALR);
 503                 DBG_SET_FLAG_MIN("allocate",    ALL);
 504                 DBG_SET_FLAG_MIN("attach",      ATT);
 505                 DBG_SET_FLAG_MIN("bind",        BND);
 506                 DBG_SET_FLAG_MIN("config",      CFG);
 507                 DBG_SET_FLAG_MIN("exec",        EXC);
 508                 DBG_SET_FLAG_MIN("exit",        EXT);
 509                 DBG_SET_FLAG_MIN("find",        FND);
 510                 DBG_SET_FLAG_MIN("flush",       FLS);
 511                 DBG_SET_FLAG_MIN("fork",        FRK);
 512                 DBG_SET_FLAG_MIN("getbuf",      GTB);
 513                 DBG_SET_FLAG_MIN("hook",        PMH);
 514                 DBG_SET_FLAG_MIN("init",        INI);
 515                 DBG_SET_FLAG_MIN("intr",        INT);
 516                 DBG_SET_FLAG_MIN("linktarget",  TLK);
 517                 DBG_SET_FLAG_MIN("mayberemove", OMR);
 518                 DBG_SET_FLAG_MIN("ops",         OPS);
 519                 DBG_SET_FLAG_MIN("read",        REA);
 520                 DBG_SET_FLAG_MIN("register",    REG);
 521                 DBG_SET_FLAG_MIN("release",     REL);
 522                 DBG_SET_FLAG_MIN("remove",      ORM);
 523                 DBG_SET_FLAG_MIN("sample",      SAM);
 524                 DBG_SET_FLAG_MIN("scheduleio",  SIO);
 525                 DBG_SET_FLAG_MIN("select",      SEL);
 526                 DBG_SET_FLAG_MIN("signal",      SIG);
 527                 DBG_SET_FLAG_MIN("swi",         SWI);
 528                 DBG_SET_FLAG_MIN("swo",         SWO);
 529                 DBG_SET_FLAG_MIN("start",       STA);
 530                 DBG_SET_FLAG_MIN("stop",        STO);
 531                 DBG_SET_FLAG_MIN("syscall",     PMS);
 532                 DBG_SET_FLAG_MIN("unlinktarget", TUL);
 533                 DBG_SET_FLAG_MIN("write",       WRI);
 534                 if (found == 0) {
 535                         /* unrecognized flag name */
 536                         error = EINVAL;
 537                         goto done;
 538                 }
 539
 540                 if (c == 0 || c == ' ' || c == '\t') {  /* end of flag group */
 541                         *newbits = tmp;
 542                         continue;
 543                 }
 544
 545                 p++;
 546                 goto newflag;
 547         }
 548
 549         /* save the new flag set */
 550         bcopy(tmpflags, &pmc_debugflags, sizeof(pmc_debugflags));
 551
 552  done:
 553         free(tmpflags, M_PMC);
 554         return error;
 555 }
 556
 557 static int
 558 pmc_debugflags_sysctl_handler(SYSCTL_HANDLER_ARGS)
 559 {
 560         char *fence, *newstr;
 561         int error;
 562         unsigned int n;
 563
 564         (void) arg1; (void) arg2; /* unused parameters */
 565
 566         n = sizeof(pmc_debugstr);
 567         newstr = malloc(n, M_PMC, M_WAITOK|M_ZERO);
 568         (void) strlcpy(newstr, pmc_debugstr, n);
 569
 570         error = sysctl_handle_string(oidp, newstr, n, req);
 571
 572         /* if there is a new string, parse and copy it */
 573         if (error == 0 && req->newptr != NULL) {
 574                 fence = newstr + (n < req->newlen ? n : req->newlen + 1);
 575                 if ((error = pmc_debugflags_parse(newstr, fence)) == 0)
 576                         (void) strlcpy(pmc_debugstr, newstr,
 577                             sizeof(pmc_debugstr));
 578         }
 579
 580         free(newstr, M_PMC);
 581
 582         return error;
 583 }
 584 #endif
 585
 586 /*
 587  * Map a row index to a classdep structure and return the adjusted row
 588  * index for the PMC class index.
 589  */
 590 static struct pmc_classdep *
 591 pmc_ri_to_classdep(struct pmc_mdep *md, int ri, int *adjri)
 592 {
 593         struct pmc_classdep *pcd;
 594
 595         (void) md;
 596
 597         KASSERT(ri >= 0 && ri < md->pmd_npmc,
 598             ("[pmc,%d] illegal row-index %d", __LINE__, ri));
 599
 600         pcd = pmc_rowindex_to_classdep[ri];
 601
 602         KASSERT(pcd != NULL,
 603             ("[pmc,%d] ri %d null pcd", __LINE__, ri));
 604
 605         *adjri = ri - pcd->pcd_ri;
 606
 607         KASSERT(*adjri >= 0 && *adjri < pcd->pcd_num,
 608             ("[pmc,%d] adjusted row-index %d", __LINE__, *adjri));
 609
 610         return (pcd);
 611 }
 612
 613 /*
 614  * Concurrency Control
 615  *
 616  * The driver manages the following data structures:
 617  *
 618  *   - target process descriptors, one per target process
 619  *   - owner process descriptors (and attached lists), one per owner process
 620  *   - lookup hash tables for owner and target processes
 621  *   - PMC descriptors (and attached lists)
 622  *   - per-cpu hardware state
 623  *   - the 'hook' variable through which the kernel calls into
 624  *     this module
 625  *   - the machine hardware state (managed by the MD layer)
 626  *
 627  * These data structures are accessed from:
 628  *
 629  * - thread context-switch code
 630  * - interrupt handlers (possibly on multiple cpus)
 631  * - kernel threads on multiple cpus running on behalf of user
 632  *   processes doing system calls
 633  * - this driver's private kernel threads
 634  *
 635  * = Locks and Locking strategy =
 636  *
 637  * The driver uses four locking strategies for its operation:
 638  *
 639  * - The global SX lock "pmc_sx" is used to protect internal
 640  *   data structures.
 641  *
 642  *   Calls into the module by syscall() start with this lock being
 643  *   held in exclusive mode.  Depending on the requested operation,
 644  *   the lock may be downgraded to 'shared' mode to allow more
 645  *   concurrent readers into the module.  Calls into the module from
 646  *   other parts of the kernel acquire the lock in shared mode.
 647  *
 648  *   This SX lock is held in exclusive mode for any operations that
 649  *   modify the linkages between the driver's internal data structures.
 650  *
 651  *   The 'pmc_hook' function pointer is also protected by this lock.
 652  *   It is only examined with the sx lock held in exclusive mode.  The
 653  *   kernel module is allowed to be unloaded only with the sx lock held
 654  *   in exclusive mode.  In normal syscall handling, after acquiring the
 655  *   pmc_sx lock we first check that 'pmc_hook' is non-null before
 656  *   proceeding.  This prevents races between the thread unloading the module
 657  *   and other threads seeking to use the module.
 658  *
 659  * - Lookups of target process structures and owner process structures
 660  *   cannot use the global "pmc_sx" SX lock because these lookups need
 661  *   to happen during context switches and in other critical sections
 662  *   where sleeping is not allowed.  We protect these lookup tables
 663  *   with their own private spin-mutexes, "pmc_processhash_mtx" and
 664  *   "pmc_ownerhash_mtx".
 665  *
 666  * - Interrupt handlers work in a lock free manner.  At interrupt
 667  *   time, handlers look at the PMC pointer (phw->phw_pmc) configured
 668  *   when the PMC was started.  If this pointer is NULL, the interrupt
 669  *   is ignored after updating driver statistics.  We ensure that this
 670  *   pointer is set (using an atomic operation if necessary) before the
 671  *   PMC hardware is started.  Conversely, this pointer is unset atomically
 672  *   only after the PMC hardware is stopped.
 673  *
 674  *   We ensure that everything needed for the operation of an
 675  *   interrupt handler is available without it needing to acquire any
 676  *   locks.  We also ensure that a PMC's software state is destroyed only
 677  *   after the PMC is taken off hardware (on all CPUs).
 678  *
 679  * - Context-switch handling with process-private PMCs needs more
 680  *   care.
 681  *
 682  *   A given process may be the target of multiple PMCs.  For example,
 683  *   PMCATTACH and PMCDETACH may be requested by a process on one CPU
 684  *   while the target process is running on another.  A PMC could also
 685  *   be getting released because its owner is exiting.  We tackle
 686  *   these situations in the following manner:
 687  *
 688  *   - each target process structure 'pmc_process' has an array
 689  *     of 'struct pmc *' pointers, one for each hardware PMC.
 690  *
 691  *   - At context switch IN time, each "target" PMC in RUNNING state
 692  *     gets started on hardware and a pointer to each PMC is copied into
 693  *     the per-cpu phw array.  The 'runcount' for the PMC is
 694  *     incremented.
 695  *
 696  *   - At context switch OUT time, all process-virtual PMCs are stopped
 697  *     on hardware.  The saved value is added to the PMCs value field
 698  *     only if the PMC is in a non-deleted state (the PMCs state could
 699  *     have changed during the current time slice).
 700  *
 701  *     Note that since in-between a switch IN on a processor and a switch
 702  *     OUT, the PMC could have been released on another CPU.  Therefore
 703  *     context switch OUT always looks at the hardware state to turn
 704  *     OFF PMCs and will update a PMC's saved value only if reachable
 705  *     from the target process record.
 706  *
 707  *   - OP PMCRELEASE could be called on a PMC at any time (the PMC could
 708  *     be attached to many processes at the time of the call and could
 709  *     be active on multiple CPUs).
 710  *
 711  *     We prevent further scheduling of the PMC by marking it as in
 712  *     state 'DELETED'.  If the runcount of the PMC is non-zero then
 713  *     this PMC is currently running on a CPU somewhere.  The thread
 714  *     doing the PMCRELEASE operation waits by repeatedly doing a
 715  *     pause() till the runcount comes to zero.
 716  *
 717  * The contents of a PMC descriptor (struct pmc) are protected using
 718  * a spin-mutex.  In order to save space, we use a mutex pool.
 719  *
 720  * In terms of lock types used by witness(4), we use:
 721  * - Type "pmc-sx", used by the global SX lock.
 722  * - Type "pmc-sleep", for sleep mutexes used by logger threads.
 723  * - Type "pmc-per-proc", for protecting PMC owner descriptors.
 724  * - Type "pmc-leaf", used for all other spin mutexes.
 725  */
 726
 727 /*
 728  * save the cpu binding of the current kthread
 729  */
 730
 731 static void
 732 pmc_save_cpu_binding(struct pmc_binding *pb)
 733 {
 734         PMCDBG0(CPU,BND,2, "save-cpu");
 735         thread_lock(curthread);
 736         pb->pb_bound = sched_is_bound(curthread);
 737         pb->pb_cpu   = curthread->td_oncpu;
 738         thread_unlock(curthread);
 739         PMCDBG1(CPU,BND,2, "save-cpu cpu=%d", pb->pb_cpu);
 740 }
 741
 742 /*
 743  * restore the cpu binding of the current thread
 744  */
 745
 746 static void
 747 pmc_restore_cpu_binding(struct pmc_binding *pb)
 748 {
 749         PMCDBG2(CPU,BND,2, "restore-cpu curcpu=%d restore=%d",
 750             curthread->td_oncpu, pb->pb_cpu);
 751         thread_lock(curthread);
 752         if (pb->pb_bound)
 753                 sched_bind(curthread, pb->pb_cpu);
 754         else
 755                 sched_unbind(curthread);
 756         thread_unlock(curthread);
 757         PMCDBG0(CPU,BND,2, "restore-cpu done");
 758 }
 759
 760 /*
 761  * move execution over the specified cpu and bind it there.
 762  */
 763
 764 static void
 765 pmc_select_cpu(int cpu)
 766 {
 767         KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
 768             ("[pmc,%d] bad cpu number %d", __LINE__, cpu));
 769
 770         /* Never move to an inactive CPU. */
 771         KASSERT(pmc_cpu_is_active(cpu), ("[pmc,%d] selecting inactive "
 772             "CPU %d", __LINE__, cpu));
 773
 774         PMCDBG1(CPU,SEL,2, "select-cpu cpu=%d", cpu);
 775         thread_lock(curthread);
 776         sched_bind(curthread, cpu);
 777         thread_unlock(curthread);
 778
 779         KASSERT(curthread->td_oncpu == cpu,
 780             ("[pmc,%d] CPU not bound [cpu=%d, curr=%d]", __LINE__,
 781                 cpu, curthread->td_oncpu));
 782
 783         PMCDBG1(CPU,SEL,2, "select-cpu cpu=%d ok", cpu);
 784 }
 785
 786 /*
 787  * Force a context switch.
 788  *
 789  * We do this by pause'ing for 1 tick -- invoking mi_switch() is not
 790  * guaranteed to force a context switch.
 791  */
 792
 793 static void
 794 pmc_force_context_switch(void)
 795 {
 796
 797         pause("pmcctx", 1);
 798 }
 799
 800 /*
 801  * Get the file name for an executable.  This is a simple wrapper
 802  * around vn_fullpath(9).
 803  */
 804
 805 static void
 806 pmc_getfilename(struct vnode *v, char **fullpath, char **freepath)
 807 {
 808
 809         *fullpath = "unknown";
 810         *freepath = NULL;
 811         vn_fullpath(curthread, v, fullpath, freepath);
 812 }
 813
 814 /*
 815  * remove an process owning PMCs
 816  */
 817
 818 void
 819 pmc_remove_owner(struct pmc_owner *po)
 820 {
 821         struct pmc *pm, *tmp;
 822
 823         sx_assert(&pmc_sx, SX_XLOCKED);
 824
 825         PMCDBG1(OWN,ORM,1, "remove-owner po=%p", po);
 826
 827         /* Remove descriptor from the owner hash table */
 828         LIST_REMOVE(po, po_next);
 829
 830         /* release all owned PMC descriptors */
 831         LIST_FOREACH_SAFE(pm, &po->po_pmcs, pm_next, tmp) {
 832                 PMCDBG1(OWN,ORM,2, "pmc=%p", pm);
 833                 KASSERT(pm->pm_owner == po,
 834                     ("[pmc,%d] owner %p != po %p", __LINE__, pm->pm_owner, po));
 835
 836                 pmc_release_pmc_descriptor(pm); /* will unlink from the list */
 837                 pmc_destroy_pmc_descriptor(pm);
 838         }
 839
 840         KASSERT(po->po_sscount == 0,
 841             ("[pmc,%d] SS count not zero", __LINE__));
 842         KASSERT(LIST_EMPTY(&po->po_pmcs),
 843             ("[pmc,%d] PMC list not empty", __LINE__));
 844
 845         /* de-configure the log file if present */
 846         if (po->po_flags & PMC_PO_OWNS_LOGFILE)
 847                 pmclog_deconfigure_log(po);
 848 }
 849
 850 /*
 851  * remove an owner process record if all conditions are met.
 852  */
 853
 854 static void
 855 pmc_maybe_remove_owner(struct pmc_owner *po)
 856 {
 857
 858         PMCDBG1(OWN,OMR,1, "maybe-remove-owner po=%p", po);
 859
 860         /*
 861          * Remove owner record if
 862          * - this process does not own any PMCs
 863          * - this process has not allocated a system-wide sampling buffer
 864          */
 865
 866         if (LIST_EMPTY(&po->po_pmcs) &&
 867             ((po->po_flags & PMC_PO_OWNS_LOGFILE) == 0)) {
 868                 pmc_remove_owner(po);
 869                 pmc_destroy_owner_descriptor(po);
 870         }
 871 }
 872
 873 /*
 874  * Add an association between a target process and a PMC.
 875  */
 876
 877 static void
 878 pmc_link_target_process(struct pmc *pm, struct pmc_process *pp)
 879 {
 880         int ri;
 881         struct pmc_target *pt;
 882 #ifdef INVARIANTS
 883         struct pmc_thread *pt_td;
 884 #endif
 885
 886         sx_assert(&pmc_sx, SX_XLOCKED);
 887
 888         KASSERT(pm != NULL && pp != NULL,
 889             ("[pmc,%d] Null pm %p or pp %p", __LINE__, pm, pp));
 890         KASSERT(PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)),
 891             ("[pmc,%d] Attaching a non-process-virtual pmc=%p to pid=%d",
 892                 __LINE__, pm, pp->pp_proc->p_pid));
 893         KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt <= ((int) md->pmd_npmc - 1),
 894             ("[pmc,%d] Illegal reference count %d for process record %p",
 895                 __LINE__, pp->pp_refcnt, (void *) pp));
 896
 897         ri = PMC_TO_ROWINDEX(pm);
 898
 899         PMCDBG3(PRC,TLK,1, "link-target pmc=%p ri=%d pmc-process=%p",
 900             pm, ri, pp);
 901
 902 #ifdef  HWPMC_DEBUG
 903         LIST_FOREACH(pt, &pm->pm_targets, pt_next)
 904             if (pt->pt_process == pp)
 905                     KASSERT(0, ("[pmc,%d] pp %p already in pmc %p targets",
 906                                 __LINE__, pp, pm));
 907 #endif
 908
 909         pt = malloc(sizeof(struct pmc_target), M_PMC, M_WAITOK|M_ZERO);
 910         pt->pt_process = pp;
 911
 912         LIST_INSERT_HEAD(&pm->pm_targets, pt, pt_next);
 913
 914         atomic_store_rel_ptr((uintptr_t *)&pp->pp_pmcs[ri].pp_pmc,
 915             (uintptr_t)pm);
 916
 917         if (pm->pm_owner->po_owner == pp->pp_proc)
 918                 pm->pm_flags |= PMC_F_ATTACHED_TO_OWNER;
 919
 920         /*
 921          * Initialize the per-process values at this row index.
 922          */
 923         pp->pp_pmcs[ri].pp_pmcval = PMC_TO_MODE(pm) == PMC_MODE_TS ?
 924             pm->pm_sc.pm_reloadcount : 0;
 925
 926         pp->pp_refcnt++;
 927
 928 #ifdef INVARIANTS
 929         /* Confirm that the per-thread values at this row index are cleared. */
 930         if (PMC_TO_MODE(pm) == PMC_MODE_TS) {
 931                 mtx_lock_spin(pp->pp_tdslock);
 932                 LIST_FOREACH(pt_td, &pp->pp_tds, pt_next) {
 933                         KASSERT(pt_td->pt_pmcs[ri].pt_pmcval == (pmc_value_t) 0,
 934                             ("[pmc,%d] pt_pmcval not cleared for pid=%d at "
 935                             "ri=%d", __LINE__, pp->pp_proc->p_pid, ri));
 936                 }
 937                 mtx_unlock_spin(pp->pp_tdslock);
 938         }
 939 #endif
 940 }
 941
 942 /*
 943  * Removes the association between a target process and a PMC.
 944  */
 945
 946 static void
 947 pmc_unlink_target_process(struct pmc *pm, struct pmc_process *pp)
 948 {
 949         int ri;
 950         struct proc *p;
 951         struct pmc_target *ptgt;
 952         struct pmc_thread *pt;
 953
 954         sx_assert(&pmc_sx, SX_XLOCKED);
 955
 956         KASSERT(pm != NULL && pp != NULL,
 957             ("[pmc,%d] Null pm %p or pp %p", __LINE__, pm, pp));
 958
 959         KASSERT(pp->pp_refcnt >= 1 && pp->pp_refcnt <= (int) md->pmd_npmc,
 960             ("[pmc,%d] Illegal ref count %d on process record %p",
 961                 __LINE__, pp->pp_refcnt, (void *) pp));
 962
 963         ri = PMC_TO_ROWINDEX(pm);
 964
 965         PMCDBG3(PRC,TUL,1, "unlink-target pmc=%p ri=%d pmc-process=%p",
 966             pm, ri, pp);
 967
 968         KASSERT(pp->pp_pmcs[ri].pp_pmc == pm,
 969             ("[pmc,%d] PMC ri %d mismatch pmc %p pp->[ri] %p", __LINE__,
 970                 ri, pm, pp->pp_pmcs[ri].pp_pmc));
 971
 972         pp->pp_pmcs[ri].pp_pmc = NULL;
 973         pp->pp_pmcs[ri].pp_pmcval = (pmc_value_t) 0;
 974
 975         /* Clear the per-thread values at this row index. */
 976         if (PMC_TO_MODE(pm) == PMC_MODE_TS) {
 977                 mtx_lock_spin(pp->pp_tdslock);
 978                 LIST_FOREACH(pt, &pp->pp_tds, pt_next)
 979                         pt->pt_pmcs[ri].pt_pmcval = (pmc_value_t) 0;
 980                 mtx_unlock_spin(pp->pp_tdslock);
 981         }
 982
 983         /* Remove owner-specific flags */
 984         if (pm->pm_owner->po_owner == pp->pp_proc) {
 985                 pp->pp_flags &= ~PMC_PP_ENABLE_MSR_ACCESS;
 986                 pm->pm_flags &= ~PMC_F_ATTACHED_TO_OWNER;
 987         }
 988
 989         pp->pp_refcnt--;
 990
 991         /* Remove the target process from the PMC structure */
 992         LIST_FOREACH(ptgt, &pm->pm_targets, pt_next)
 993                 if (ptgt->pt_process == pp)
 994                         break;
 995
 996         KASSERT(ptgt != NULL, ("[pmc,%d] process %p (pp: %p) not found "
 997                     "in pmc %p", __LINE__, pp->pp_proc, pp, pm));
 998
 999         LIST_REMOVE(ptgt, pt_next);
1000         free(ptgt, M_PMC);
1001
1002         /* if the PMC now lacks targets, send the owner a SIGIO */
1003         if (LIST_EMPTY(&pm->pm_targets)) {
1004                 p = pm->pm_owner->po_owner;
1005                 PROC_LOCK(p);
1006                 kern_psignal(p, SIGIO);
1007                 PROC_UNLOCK(p);
1008
1009                 PMCDBG2(PRC,SIG,2, "signalling proc=%p signal=%d", p,
1010                     SIGIO);
1011         }
1012 }
1013
1014 /*
1015  * Check if PMC 'pm' may be attached to target process 't'.
1016  */
1017
1018 static int
1019 pmc_can_attach(struct pmc *pm, struct proc *t)
1020 {
1021         struct proc *o;         /* pmc owner */
1022         struct ucred *oc, *tc;  /* owner, target credentials */
1023         int decline_attach, i;
1024
1025         /*
1026          * A PMC's owner can always attach that PMC to itself.
1027          */
1028
1029         if ((o = pm->pm_owner->po_owner) == t)
1030                 return 0;
1031
1032         PROC_LOCK(o);
1033         oc = o->p_ucred;
1034         crhold(oc);
1035         PROC_UNLOCK(o);
1036
1037         PROC_LOCK(t);
1038         tc = t->p_ucred;
1039         crhold(tc);
1040         PROC_UNLOCK(t);
1041
1042         /*
1043          * The effective uid of the PMC owner should match at least one
1044          * of the {effective,real,saved} uids of the target process.
1045          */
1046
1047         decline_attach = oc->cr_uid != tc->cr_uid &&
1048             oc->cr_uid != tc->cr_svuid &&
1049             oc->cr_uid != tc->cr_ruid;
1050
1051         /*
1052          * Every one of the target's group ids, must be in the owner's
1053          * group list.
1054          */
1055         for (i = 0; !decline_attach && i < tc->cr_ngroups; i++)
1056                 decline_attach = !groupmember(tc->cr_groups[i], oc);
1057
1058         /* check the read and saved gids too */
1059         if (decline_attach == 0)
1060                 decline_attach = !groupmember(tc->cr_rgid, oc) ||
1061                     !groupmember(tc->cr_svgid, oc);
1062
1063         crfree(tc);
1064         crfree(oc);
1065
1066         return !decline_attach;
1067 }
1068
1069 /*
1070  * Attach a process to a PMC.
1071  */
1072
1073 static int
1074 pmc_attach_one_process(struct proc *p, struct pmc *pm)
1075 {
1076         int ri, error;
1077         char *fullpath, *freepath;
1078         struct pmc_process      *pp;
1079
1080         sx_assert(&pmc_sx, SX_XLOCKED);
1081
1082         PMCDBG5(PRC,ATT,2, "attach-one pm=%p ri=%d proc=%p (%d, %s)", pm,
1083             PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm);
1084
1085         /*
1086          * Locate the process descriptor corresponding to process 'p',
1087          * allocating space as needed.
1088          *
1089          * Verify that rowindex 'pm_rowindex' is free in the process
1090          * descriptor.
1091          *
1092          * If not, allocate space for a descriptor and link the
1093          * process descriptor and PMC.
1094          */
1095         ri = PMC_TO_ROWINDEX(pm);
1096
1097         /* mark process as using HWPMCs */
1098         PROC_LOCK(p);
1099         p->p_flag |= P_HWPMC;
1100         PROC_UNLOCK(p);
1101
1102         if ((pp = pmc_find_process_descriptor(p, PMC_FLAG_ALLOCATE)) == NULL) {
1103                 error = ENOMEM;
1104                 goto fail;
1105         }
1106
1107         if (pp->pp_pmcs[ri].pp_pmc == pm) {/* already present at slot [ri] */
1108                 error = EEXIST;
1109                 goto fail;
1110         }
1111
1112         if (pp->pp_pmcs[ri].pp_pmc != NULL) {
1113                 error = EBUSY;
1114                 goto fail;
1115         }
1116
1117         pmc_link_target_process(pm, pp);
1118
1119         if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)) &&
1120             (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) == 0)
1121                 pm->pm_flags |= PMC_F_NEEDS_LOGFILE;
1122
1123         pm->pm_flags |= PMC_F_ATTACH_DONE; /* mark as attached */
1124
1125         /* issue an attach event to a configured log file */
1126         if (pm->pm_owner->po_flags & PMC_PO_OWNS_LOGFILE) {
1127                 if (p->p_flag & P_KPROC) {
1128                         fullpath = kernelname;
1129                         freepath = NULL;
1130                 } else {
1131                         pmc_getfilename(p->p_textvp, &fullpath, &freepath);
1132                         pmclog_process_pmcattach(pm, p->p_pid, fullpath);
1133                 }
1134                 free(freepath, M_TEMP);
1135                 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)))
1136                         pmc_log_process_mappings(pm->pm_owner, p);
1137         }
1138
1139         return (0);
1140  fail:
1141         PROC_LOCK(p);
1142         p->p_flag &= ~P_HWPMC;
1143         PROC_UNLOCK(p);
1144         return (error);
1145 }
1146
1147 /*
1148  * Attach a process and optionally its children
1149  */
1150
1151 static int
1152 pmc_attach_process(struct proc *p, struct pmc *pm)
1153 {
1154         int error;
1155         struct proc *top;
1156
1157         sx_assert(&pmc_sx, SX_XLOCKED);
1158
1159         PMCDBG5(PRC,ATT,1, "attach pm=%p ri=%d proc=%p (%d, %s)", pm,
1160             PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm);
1161
1162
1163         /*
1164          * If this PMC successfully allowed a GETMSR operation
1165          * in the past, disallow further ATTACHes.
1166          */
1167
1168         if ((pm->pm_flags & PMC_PP_ENABLE_MSR_ACCESS) != 0)
1169                 return EPERM;
1170
1171         if ((pm->pm_flags & PMC_F_DESCENDANTS) == 0)
1172                 return pmc_attach_one_process(p, pm);
1173
1174         /*
1175          * Traverse all child processes, attaching them to
1176          * this PMC.
1177          */
1178
1179         sx_slock(&proctree_lock);
1180
1181         top = p;
1182
1183         for (;;) {
1184                 if ((error = pmc_attach_one_process(p, pm)) != 0)
1185                         break;
1186                 if (!LIST_EMPTY(&p->p_children))
1187                         p = LIST_FIRST(&p->p_children);
1188                 else for (;;) {
1189                         if (p == top)
1190                                 goto done;
1191                         if (LIST_NEXT(p, p_sibling)) {
1192                                 p = LIST_NEXT(p, p_sibling);
1193                                 break;
1194                         }
1195                         p = p->p_pptr;
1196                 }
1197         }
1198
1199         if (error)
1200                 (void) pmc_detach_process(top, pm);
1201
1202  done:
1203         sx_sunlock(&proctree_lock);
1204         return error;
1205 }
1206
1207 /*
1208  * Detach a process from a PMC.  If there are no other PMCs tracking
1209  * this process, remove the process structure from its hash table.  If
1210  * 'flags' contains PMC_FLAG_REMOVE, then free the process structure.
1211  */
1212
1213 static int
1214 pmc_detach_one_process(struct proc *p, struct pmc *pm, int flags)
1215 {
1216         int ri;
1217         struct pmc_process *pp;
1218
1219         sx_assert(&pmc_sx, SX_XLOCKED);
1220
1221         KASSERT(pm != NULL,
1222             ("[pmc,%d] null pm pointer", __LINE__));
1223
1224         ri = PMC_TO_ROWINDEX(pm);
1225
1226         PMCDBG6(PRC,ATT,2, "detach-one pm=%p ri=%d proc=%p (%d, %s) flags=0x%x",
1227             pm, ri, p, p->p_pid, p->p_comm, flags);
1228
1229         if ((pp = pmc_find_process_descriptor(p, 0)) == NULL)
1230                 return ESRCH;
1231
1232         if (pp->pp_pmcs[ri].pp_pmc != pm)
1233                 return EINVAL;
1234
1235         pmc_unlink_target_process(pm, pp);
1236
1237         /* Issue a detach entry if a log file is configured */
1238         if (pm->pm_owner->po_flags & PMC_PO_OWNS_LOGFILE)
1239                 pmclog_process_pmcdetach(pm, p->p_pid);
1240
1241         /*
1242          * If there are no PMCs targeting this process, we remove its
1243          * descriptor from the target hash table and unset the P_HWPMC
1244          * flag in the struct proc.
1245          */
1246         KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt <= (int) md->pmd_npmc,
1247             ("[pmc,%d] Illegal refcnt %d for process struct %p",
1248                 __LINE__, pp->pp_refcnt, pp));
1249
1250         if (pp->pp_refcnt != 0) /* still a target of some PMC */
1251                 return 0;
1252
1253         pmc_remove_process_descriptor(pp);
1254
1255         if (flags & PMC_FLAG_REMOVE)
1256                 pmc_destroy_process_descriptor(pp);
1257
1258         PROC_LOCK(p);
1259         p->p_flag &= ~P_HWPMC;
1260         PROC_UNLOCK(p);
1261
1262         return 0;
1263 }
1264
1265 /*
1266  * Detach a process and optionally its descendants from a PMC.
1267  */
1268
1269 static int
1270 pmc_detach_process(struct proc *p, struct pmc *pm)
1271 {
1272         struct proc *top;
1273
1274         sx_assert(&pmc_sx, SX_XLOCKED);
1275
1276         PMCDBG5(PRC,ATT,1, "detach pm=%p ri=%d proc=%p (%d, %s)", pm,
1277             PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm);
1278
1279         if ((pm->pm_flags & PMC_F_DESCENDANTS) == 0)
1280                 return pmc_detach_one_process(p, pm, PMC_FLAG_REMOVE);
1281
1282         /*
1283          * Traverse all children, detaching them from this PMC.  We
1284          * ignore errors since we could be detaching a PMC from a
1285          * partially attached proc tree.
1286          */
1287
1288         sx_slock(&proctree_lock);
1289
1290         top = p;
1291
1292         for (;;) {
1293                 (void) pmc_detach_one_process(p, pm, PMC_FLAG_REMOVE);
1294
1295                 if (!LIST_EMPTY(&p->p_children))
1296                         p = LIST_FIRST(&p->p_children);
1297                 else for (;;) {
1298                         if (p == top)
1299                                 goto done;
1300                         if (LIST_NEXT(p, p_sibling)) {
1301                                 p = LIST_NEXT(p, p_sibling);
1302                                 break;
1303                         }
1304                         p = p->p_pptr;
1305                 }
1306         }
1307
1308  done:
1309         sx_sunlock(&proctree_lock);
1310
1311         if (LIST_EMPTY(&pm->pm_targets))
1312                 pm->pm_flags &= ~PMC_F_ATTACH_DONE;
1313
1314         return 0;
1315 }
1316
1317
1318 /*
1319  * Thread context switch IN
1320  */
1321
1322 static void
1323 pmc_process_csw_in(struct thread *td)
1324 {
1325         int cpu;
1326         unsigned int adjri, ri;
1327         struct pmc *pm;
1328         struct proc *p;
1329         struct pmc_cpu *pc;
1330         struct pmc_hw *phw;
1331         pmc_value_t newvalue;
1332         struct pmc_process *pp;
1333         struct pmc_thread *pt;
1334         struct pmc_classdep *pcd;
1335
1336         p = td->td_proc;
1337         pt = NULL;
1338         if ((pp = pmc_find_process_descriptor(p, PMC_FLAG_NONE)) == NULL)
1339                 return;
1340
1341         KASSERT(pp->pp_proc == td->td_proc,
1342             ("[pmc,%d] not my thread state", __LINE__));
1343
1344         critical_enter(); /* no preemption from this point */
1345
1346         cpu = PCPU_GET(cpuid); /* td->td_oncpu is invalid */
1347
1348         PMCDBG5(CSW,SWI,1, "cpu=%d proc=%p (%d, %s) pp=%p", cpu, p,
1349             p->p_pid, p->p_comm, pp);
1350
1351         KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
1352             ("[pmc,%d] weird CPU id %d", __LINE__, cpu));
1353
1354         pc = pmc_pcpu[cpu];
1355
1356         for (ri = 0; ri < md->pmd_npmc; ri++) {
1357
1358                 if ((pm = pp->pp_pmcs[ri].pp_pmc) == NULL)
1359                         continue;
1360
1361                 KASSERT(PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)),
1362                     ("[pmc,%d] Target PMC in non-virtual mode (%d)",
1363                         __LINE__, PMC_TO_MODE(pm)));
1364
1365                 KASSERT(PMC_TO_ROWINDEX(pm) == ri,
1366                     ("[pmc,%d] Row index mismatch pmc %d != ri %d",
1367                         __LINE__, PMC_TO_ROWINDEX(pm), ri));
1368
1369                 /*
1370                  * Only PMCs that are marked as 'RUNNING' need
1371                  * be placed on hardware.
1372                  */
1373
1374                 if (pm->pm_state != PMC_STATE_RUNNING)
1375                         continue;
1376
1377                 /* increment PMC runcount */
1378                 counter_u64_add(pm->pm_runcount, 1);
1379
1380                 /* configure the HWPMC we are going to use. */
1381                 pcd = pmc_ri_to_classdep(md, ri, &adjri);
1382                 pcd->pcd_config_pmc(cpu, adjri, pm);
1383
1384                 phw = pc->pc_hwpmcs[ri];
1385
1386                 KASSERT(phw != NULL,
1387                     ("[pmc,%d] null hw pointer", __LINE__));
1388
1389                 KASSERT(phw->phw_pmc == pm,
1390                     ("[pmc,%d] hw->pmc %p != pmc %p", __LINE__,
1391                         phw->phw_pmc, pm));
1392
1393                 /*
1394                  * Write out saved value and start the PMC.
1395                  *
1396                  * Sampling PMCs use a per-thread value, while
1397                  * counting mode PMCs use a per-pmc value that is
1398                  * inherited across descendants.
1399                  */
1400                 if (PMC_TO_MODE(pm) == PMC_MODE_TS) {
1401                         if (pt == NULL)
1402                                 pt = pmc_find_thread_descriptor(pp, td,
1403                                     PMC_FLAG_NONE);
1404
1405                         KASSERT(pt != NULL,
1406                             ("[pmc,%d] No thread found for td=%p", __LINE__,
1407                             td));
1408
1409                         mtx_pool_lock_spin(pmc_mtxpool, pm);
1410
1411                         /*
1412                          * If we have a thread descriptor, use the per-thread
1413                          * counter in the descriptor. If not, we will use
1414                          * a per-process counter.
1415                          *
1416                          * TODO: Remove the per-process "safety net" once
1417                          * we have thoroughly tested that we don't hit the
1418                          * above assert.
1419                          */
1420                         if (pt != NULL) {
1421                                 if (pt->pt_pmcs[ri].pt_pmcval > 0)
1422                                         newvalue = pt->pt_pmcs[ri].pt_pmcval;
1423                                 else
1424                                         newvalue = pm->pm_sc.pm_reloadcount;
1425                         } else {
1426                                 /*
1427                                  * Use the saved value calculated after the most
1428                                  * recent time a thread using the shared counter
1429                                  * switched out. Reset the saved count in case
1430                                  * another thread from this process switches in
1431                                  * before any threads switch out.
1432                                  */
1433
1434                                 newvalue = pp->pp_pmcs[ri].pp_pmcval;
1435                                 pp->pp_pmcs[ri].pp_pmcval =
1436                                     pm->pm_sc.pm_reloadcount;
1437                         }
1438                         mtx_pool_unlock_spin(pmc_mtxpool, pm);
1439                         KASSERT(newvalue > 0 && newvalue <=
1440                             pm->pm_sc.pm_reloadcount,
1441                             ("[pmc,%d] pmcval outside of expected range cpu=%d "
1442                             "ri=%d pmcval=%jx pm_reloadcount=%jx", __LINE__,
1443                             cpu, ri, newvalue, pm->pm_sc.pm_reloadcount));
1444                 } else {
1445                         KASSERT(PMC_TO_MODE(pm) == PMC_MODE_TC,
1446                             ("[pmc,%d] illegal mode=%d", __LINE__,
1447                             PMC_TO_MODE(pm)));
1448                         mtx_pool_lock_spin(pmc_mtxpool, pm);
1449                         newvalue = PMC_PCPU_SAVED(cpu, ri) =
1450                             pm->pm_gv.pm_savedvalue;
1451                         mtx_pool_unlock_spin(pmc_mtxpool, pm);
1452                 }
1453
1454                 PMCDBG3(CSW,SWI,1,"cpu=%d ri=%d new=%jd", cpu, ri, newvalue);
1455
1456                 pcd->pcd_write_pmc(cpu, adjri, newvalue);
1457
1458                 /* If a sampling mode PMC, reset stalled state. */
1459                 if (PMC_TO_MODE(pm) == PMC_MODE_TS)
1460                         pm->pm_pcpu_state[cpu].pps_stalled = 0;
1461
1462                 /* Indicate that we desire this to run. */
1463                 pm->pm_pcpu_state[cpu].pps_cpustate = 1;
1464
1465                 /* Start the PMC. */
1466                 pcd->pcd_start_pmc(cpu, adjri);
1467         }
1468
1469         /*
1470          * perform any other architecture/cpu dependent thread
1471          * switch-in actions.
1472          */
1473
1474         (void) (*md->pmd_switch_in)(pc, pp);
1475
1476         critical_exit();
1477
1478 }
1479
1480 /*
1481  * Thread context switch OUT.
1482  */
1483
1484 static void
1485 pmc_process_csw_out(struct thread *td)
1486 {
1487         int cpu;
1488         int64_t tmp;
1489         struct pmc *pm;
1490         struct proc *p;
1491         enum pmc_mode mode;
1492         struct pmc_cpu *pc;
1493         pmc_value_t newvalue;
1494         unsigned int adjri, ri;
1495         struct pmc_process *pp;
1496         struct pmc_thread *pt = NULL;
1497         struct pmc_classdep *pcd;
1498
1499
1500         /*
1501          * Locate our process descriptor; this may be NULL if
1502          * this process is exiting and we have already removed
1503          * the process from the target process table.
1504          *
1505          * Note that due to kernel preemption, multiple
1506          * context switches may happen while the process is
1507          * exiting.
1508          *
1509          * Note also that if the target process cannot be
1510          * found we still need to deconfigure any PMCs that
1511          * are currently running on hardware.
1512          */
1513
1514         p = td->td_proc;
1515         pp = pmc_find_process_descriptor(p, PMC_FLAG_NONE);
1516
1517         /*
1518          * save PMCs
1519          */
1520
1521         critical_enter();
1522
1523         cpu = PCPU_GET(cpuid); /* td->td_oncpu is invalid */
1524
1525         PMCDBG5(CSW,SWO,1, "cpu=%d proc=%p (%d, %s) pp=%p", cpu, p,
1526             p->p_pid, p->p_comm, pp);
1527
1528         KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
1529             ("[pmc,%d weird CPU id %d", __LINE__, cpu));
1530
1531         pc = pmc_pcpu[cpu];
1532
1533         /*
1534          * When a PMC gets unlinked from a target PMC, it will
1535          * be removed from the target's pp_pmc[] array.
1536          *
1537          * However, on a MP system, the target could have been
1538          * executing on another CPU at the time of the unlink.
1539          * So, at context switch OUT time, we need to look at
1540          * the hardware to determine if a PMC is scheduled on
1541          * it.
1542          */
1543
1544         for (ri = 0; ri < md->pmd_npmc; ri++) {
1545
1546                 pcd = pmc_ri_to_classdep(md, ri, &adjri);
1547                 pm  = NULL;
1548                 (void) (*pcd->pcd_get_config)(cpu, adjri, &pm);
1549
1550                 if (pm == NULL) /* nothing at this row index */
1551                         continue;
1552
1553                 mode = PMC_TO_MODE(pm);
1554                 if (!PMC_IS_VIRTUAL_MODE(mode))
1555                         continue; /* not a process virtual PMC */
1556
1557                 KASSERT(PMC_TO_ROWINDEX(pm) == ri,
1558                     ("[pmc,%d] ri mismatch pmc(%d) ri(%d)",
1559                         __LINE__, PMC_TO_ROWINDEX(pm), ri));
1560
1561                 /*
1562                  * Change desired state, and then stop if not stalled.
1563                  * This two-step dance should avoid race conditions where
1564                  * an interrupt re-enables the PMC after this code has
1565                  * already checked the pm_stalled flag.
1566                  */
1567                 pm->pm_pcpu_state[cpu].pps_cpustate = 0;
1568                 if (pm->pm_pcpu_state[cpu].pps_stalled == 0)
1569                         pcd->pcd_stop_pmc(cpu, adjri);
1570
1571                 /* reduce this PMC's runcount */
1572                 counter_u64_add(pm->pm_runcount, -1);
1573
1574                 /*
1575                  * If this PMC is associated with this process,
1576                  * save the reading.
1577                  */
1578
1579                 if (pm->pm_state != PMC_STATE_DELETED && pp != NULL &&
1580                     pp->pp_pmcs[ri].pp_pmc != NULL) {
1581                         KASSERT(pm == pp->pp_pmcs[ri].pp_pmc,
1582                             ("[pmc,%d] pm %p != pp_pmcs[%d] %p", __LINE__,
1583                                 pm, ri, pp->pp_pmcs[ri].pp_pmc));
1584
1585                         KASSERT(pp->pp_refcnt > 0,
1586                             ("[pmc,%d] pp refcnt = %d", __LINE__,
1587                                 pp->pp_refcnt));
1588
1589                         pcd->pcd_read_pmc(cpu, adjri, &newvalue);
1590
1591                         if (mode == PMC_MODE_TS) {
1592                                 PMCDBG3(CSW,SWO,1,"cpu=%d ri=%d val=%jd (samp)",
1593                                     cpu, ri, newvalue);
1594
1595                                 if (pt == NULL)
1596                                         pt = pmc_find_thread_descriptor(pp, td,
1597                                             PMC_FLAG_NONE);
1598
1599                                 KASSERT(pt != NULL,
1600                                     ("[pmc,%d] No thread found for td=%p",
1601                                     __LINE__, td));
1602
1603                                 mtx_pool_lock_spin(pmc_mtxpool, pm);
1604
1605                                 /*
1606                                  * If we have a thread descriptor, save the
1607                                  * per-thread counter in the descriptor. If not,
1608                                  * we will update the per-process counter.
1609                                  *
1610                                  * TODO: Remove the per-process "safety net"
1611                                  * once we have thoroughly tested that we
1612                                  * don't hit the above assert.
1613                                  */
1614                                 if (pt != NULL)
1615                                         pt->pt_pmcs[ri].pt_pmcval = newvalue;
1616                                 else {
1617                                         /*
1618                                          * For sampling process-virtual PMCs,
1619                                          * newvalue is the number of events to
1620                                          * be seen until the next sampling
1621                                          * interrupt. We can just add the events
1622                                          * left from this invocation to the
1623                                          * counter, then adjust in case we
1624                                          * overflow our range.
1625                                          *
1626                                          * (Recall that we reload the counter
1627                                          * every time we use it.)
1628                                          */
1629                                         pp->pp_pmcs[ri].pp_pmcval += newvalue;
1630                                         if (pp->pp_pmcs[ri].pp_pmcval >
1631                                             pm->pm_sc.pm_reloadcount)
1632                                                 pp->pp_pmcs[ri].pp_pmcval -=
1633                                                     pm->pm_sc.pm_reloadcount;
1634                                 }
1635                                 mtx_pool_unlock_spin(pmc_mtxpool, pm);
1636                         } else {
1637                                 tmp = newvalue - PMC_PCPU_SAVED(cpu,ri);
1638
1639                                 PMCDBG3(CSW,SWO,1,"cpu=%d ri=%d tmp=%jd (count)",
1640                                     cpu, ri, tmp);
1641
1642                                 /*
1643                                  * For counting process-virtual PMCs,
1644                                  * we expect the count to be
1645                                  * increasing monotonically, modulo a 64
1646                                  * bit wraparound.
1647                                  */
1648                                 KASSERT(tmp >= 0,
1649                                     ("[pmc,%d] negative increment cpu=%d "
1650                                      "ri=%d newvalue=%jx saved=%jx "
1651                                      "incr=%jx", __LINE__, cpu, ri,
1652                                      newvalue, PMC_PCPU_SAVED(cpu,ri), tmp));
1653
1654                                 mtx_pool_lock_spin(pmc_mtxpool, pm);
1655                                 pm->pm_gv.pm_savedvalue += tmp;
1656                                 pp->pp_pmcs[ri].pp_pmcval += tmp;
1657                                 mtx_pool_unlock_spin(pmc_mtxpool, pm);
1658
1659                                 if (pm->pm_flags & PMC_F_LOG_PROCCSW)
1660                                         pmclog_process_proccsw(pm, pp, tmp, td);
1661                         }
1662                 }
1663
1664                 /* mark hardware as free */
1665                 pcd->pcd_config_pmc(cpu, adjri, NULL);
1666         }
1667
1668         /*
1669          * perform any other architecture/cpu dependent thread
1670          * switch out functions.
1671          */
1672
1673         (void) (*md->pmd_switch_out)(pc, pp);
1674
1675         critical_exit();
1676 }
1677
1678 /*
1679  * A new thread for a process.
1680  */
1681 static void
1682 pmc_process_thread_add(struct thread *td)
1683 {
1684         struct pmc_process *pmc;
1685
1686         pmc = pmc_find_process_descriptor(td->td_proc, PMC_FLAG_NONE);
1687         if (pmc != NULL)
1688                 pmc_find_thread_descriptor(pmc, td, PMC_FLAG_ALLOCATE);
1689 }
1690
1691 /*
1692  * A thread delete for a process.
1693  */
1694 static void
1695 pmc_process_thread_delete(struct thread *td)
1696 {
1697         struct pmc_process *pmc;
1698
1699         pmc = pmc_find_process_descriptor(td->td_proc, PMC_FLAG_NONE);
1700         if (pmc != NULL)
1701                 pmc_thread_descriptor_pool_free(pmc_find_thread_descriptor(pmc,
1702                     td, PMC_FLAG_REMOVE));
1703 }
1704
1705 /*
1706  * A mapping change for a process.
1707  */
1708
1709 static void
1710 pmc_process_mmap(struct thread *td, struct pmckern_map_in *pkm)
1711 {
1712         int ri;
1713         pid_t pid;
1714         char *fullpath, *freepath;
1715         const struct pmc *pm;
1716         struct pmc_owner *po;
1717         const struct pmc_process *pp;
1718
1719         freepath = fullpath = NULL;
1720         epoch_exit_preempt(global_epoch_preempt);
1721         pmc_getfilename((struct vnode *) pkm->pm_file, &fullpath, &freepath);
1722
1723         pid = td->td_proc->p_pid;
1724
1725         epoch_enter_preempt(global_epoch_preempt);
1726         /* Inform owners of all system-wide sampling PMCs. */
1727         CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext)
1728             if (po->po_flags & PMC_PO_OWNS_LOGFILE)
1729                         pmclog_process_map_in(po, pid, pkm->pm_address, fullpath);
1730
1731         if ((pp = pmc_find_process_descriptor(td->td_proc, 0)) == NULL)
1732                 goto done;
1733
1734         /*
1735          * Inform sampling PMC owners tracking this process.
1736          */
1737         for (ri = 0; ri < md->pmd_npmc; ri++)
1738                 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL &&
1739                     PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)))
1740                         pmclog_process_map_in(pm->pm_owner,
1741                             pid, pkm->pm_address, fullpath);
1742
1743   done:
1744         if (freepath)
1745                 free(freepath, M_TEMP);
1746 }
1747
1748
1749 /*
1750  * Log an munmap request.
1751  */
1752
1753 static void
1754 pmc_process_munmap(struct thread *td, struct pmckern_map_out *pkm)
1755 {
1756         int ri;
1757         pid_t pid;
1758         struct pmc_owner *po;
1759         const struct pmc *pm;
1760         const struct pmc_process *pp;
1761
1762         pid = td->td_proc->p_pid;
1763
1764         epoch_enter_preempt(global_epoch_preempt);
1765         CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext)
1766             if (po->po_flags & PMC_PO_OWNS_LOGFILE)
1767                 pmclog_process_map_out(po, pid, pkm->pm_address,
1768                     pkm->pm_address + pkm->pm_size);
1769         epoch_exit_preempt(global_epoch_preempt);
1770
1771         if ((pp = pmc_find_process_descriptor(td->td_proc, 0)) == NULL)
1772                 return;
1773
1774         for (ri = 0; ri < md->pmd_npmc; ri++)
1775                 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL &&
1776                     PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)))
1777                         pmclog_process_map_out(pm->pm_owner, pid,
1778                             pkm->pm_address, pkm->pm_address + pkm->pm_size);
1779 }
1780
1781 /*
1782  * Log mapping information about the kernel.
1783  */
1784
1785 static void
1786 pmc_log_kernel_mappings(struct pmc *pm)
1787 {
1788         struct pmc_owner *po;
1789         struct pmckern_map_in *km, *kmbase;
1790
1791         MPASS(in_epoch() || sx_xlocked(&pmc_sx));
1792         KASSERT(PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)),
1793             ("[pmc,%d] non-sampling PMC (%p) desires mapping information",
1794                 __LINE__, (void *) pm));
1795
1796         po = pm->pm_owner;
1797
1798         if (po->po_flags & PMC_PO_INITIAL_MAPPINGS_DONE)
1799                 return;
1800
1801         /*
1802          * Log the current set of kernel modules.
1803          */
1804         kmbase = linker_hwpmc_list_objects();
1805         for (km = kmbase; km->pm_file != NULL; km++) {
1806                 PMCDBG2(LOG,REG,1,"%s %p", (char *) km->pm_file,
1807                     (void *) km->pm_address);
1808                 pmclog_process_map_in(po, (pid_t) -1, km->pm_address,
1809                     km->pm_file);
1810         }
1811         free(kmbase, M_LINKER);
1812
1813         po->po_flags |= PMC_PO_INITIAL_MAPPINGS_DONE;
1814 }
1815
1816 /*
1817  * Log the mappings for a single process.
1818  */
1819
1820 static void
1821 pmc_log_process_mappings(struct pmc_owner *po, struct proc *p)
1822 {
1823         vm_map_t map;
1824         struct vnode *vp;
1825         struct vmspace *vm;
1826         vm_map_entry_t entry;
1827         vm_offset_t last_end;
1828         u_int last_timestamp;
1829         struct vnode *last_vp;
1830         vm_offset_t start_addr;
1831         vm_object_t obj, lobj, tobj;
1832         char *fullpath, *freepath;
1833
1834         last_vp = NULL;
1835         last_end = (vm_offset_t) 0;
1836         fullpath = freepath = NULL;
1837
1838         if ((vm = vmspace_acquire_ref(p)) == NULL)
1839                 return;
1840
1841         map = &vm->vm_map;
1842         vm_map_lock_read(map);
1843
1844         for (entry = map->header.next; entry != &map->header; entry = entry->next) {
1845
1846                 if (entry == NULL) {
1847                         PMCDBG2(LOG,OPS,2, "hwpmc: vm_map entry unexpectedly "
1848                             "NULL! pid=%d vm_map=%p\n", p->p_pid, map);
1849                         break;
1850                 }
1851
1852                 /*
1853                  * We only care about executable map entries.
1854                  */
1855                 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) ||
1856                     !(entry->protection & VM_PROT_EXECUTE) ||
1857                     (entry->object.vm_object == NULL)) {
1858                         continue;
1859                 }
1860
1861                 obj = entry->object.vm_object;
1862                 VM_OBJECT_RLOCK(obj);
1863
1864                 /*
1865                  * Walk the backing_object list to find the base
1866                  * (non-shadowed) vm_object.
1867                  */
1868                 for (lobj = tobj = obj; tobj != NULL; tobj = tobj->backing_object) {
1869                         if (tobj != obj)
1870                                 VM_OBJECT_RLOCK(tobj);
1871                         if (lobj != obj)
1872                                 VM_OBJECT_RUNLOCK(lobj);
1873                         lobj = tobj;
1874                 }
1875
1876                 /*
1877                  * At this point lobj is the base vm_object and it is locked.
1878                  */
1879                 if (lobj == NULL) {
1880                         PMCDBG3(LOG,OPS,2, "hwpmc: lobj unexpectedly NULL! pid=%d "
1881                             "vm_map=%p vm_obj=%p\n", p->p_pid, map, obj);
1882                         VM_OBJECT_RUNLOCK(obj);
1883                         continue;
1884                 }
1885
1886                 vp = vm_object_vnode(lobj);
1887                 if (vp == NULL) {
1888                         if (lobj != obj)
1889                                 VM_OBJECT_RUNLOCK(lobj);
1890                         VM_OBJECT_RUNLOCK(obj);
1891                         continue;
1892                 }
1893
1894                 /*
1895                  * Skip contiguous regions that point to the same
1896                  * vnode, so we don't emit redundant MAP-IN
1897                  * directives.
1898                  */
1899                 if (entry->start == last_end && vp == last_vp) {
1900                         last_end = entry->end;
1901                         if (lobj != obj)
1902                                 VM_OBJECT_RUNLOCK(lobj);
1903                         VM_OBJECT_RUNLOCK(obj);
1904                         continue;
1905                 }
1906
1907                 /*
1908                  * We don't want to keep the proc's vm_map or this
1909                  * vm_object locked while we walk the pathname, since
1910                  * vn_fullpath() can sleep.  However, if we drop the
1911                  * lock, it's possible for concurrent activity to
1912                  * modify the vm_map list.  To protect against this,
1913                  * we save the vm_map timestamp before we release the
1914                  * lock, and check it after we reacquire the lock
1915                  * below.
1916                  */
1917                 start_addr = entry->start;
1918                 last_end = entry->end;
1919                 last_timestamp = map->timestamp;
1920                 vm_map_unlock_read(map);
1921
1922                 vref(vp);
1923                 if (lobj != obj)
1924                         VM_OBJECT_RUNLOCK(lobj);
1925
1926                 VM_OBJECT_RUNLOCK(obj);
1927
1928                 freepath = NULL;
1929                 pmc_getfilename(vp, &fullpath, &freepath);
1930                 last_vp = vp;
1931
1932                 vrele(vp);
1933
1934                 vp = NULL;
1935                 pmclog_process_map_in(po, p->p_pid, start_addr, fullpath);
1936                 if (freepath)
1937                         free(freepath, M_TEMP);
1938
1939                 vm_map_lock_read(map);
1940
1941                 /*
1942                  * If our saved timestamp doesn't match, this means
1943                  * that the vm_map was modified out from under us and
1944                  * we can't trust our current "entry" pointer.  Do a
1945                  * new lookup for this entry.  If there is no entry
1946                  * for this address range, vm_map_lookup_entry() will
1947                  * return the previous one, so we always want to go to
1948                  * entry->next on the next loop iteration.
1949                  *
1950                  * There is an edge condition here that can occur if
1951                  * there is no entry at or before this address.  In
1952                  * this situation, vm_map_lookup_entry returns
1953                  * &map->header, which would cause our loop to abort
1954                  * without processing the rest of the map.  However,
1955                  * in practice this will never happen for process
1956                  * vm_map.  This is because the executable's text
1957                  * segment is the first mapping in the proc's address
1958                  * space, and this mapping is never removed until the
1959                  * process exits, so there will always be a non-header
1960                  * entry at or before the requested address for
1961                  * vm_map_lookup_entry to return.
1962                  */
1963                 if (map->timestamp != last_timestamp)
1964                         vm_map_lookup_entry(map, last_end - 1, &entry);
1965         }
1966
1967         vm_map_unlock_read(map);
1968         vmspace_free(vm);
1969         return;
1970 }
1971
1972 /*
1973  * Log mappings for all processes in the system.
1974  */
1975
1976 static void
1977 pmc_log_all_process_mappings(struct pmc_owner *po)
1978 {
1979         struct proc *p, *top;
1980
1981         sx_assert(&pmc_sx, SX_XLOCKED);
1982
1983         if ((p = pfind(1)) == NULL)
1984                 panic("[pmc,%d] Cannot find init", __LINE__);
1985
1986         PROC_UNLOCK(p);
1987
1988         sx_slock(&proctree_lock);
1989
1990         top = p;
1991
1992         for (;;) {
1993                 pmc_log_process_mappings(po, p);
1994                 if (!LIST_EMPTY(&p->p_children))
1995                         p = LIST_FIRST(&p->p_children);
1996                 else for (;;) {
1997                         if (p == top)
1998                                 goto done;
1999                         if (LIST_NEXT(p, p_sibling)) {
2000                                 p = LIST_NEXT(p, p_sibling);
2001                                 break;
2002                         }
2003                         p = p->p_pptr;
2004                 }
2005         }
2006  done:
2007         sx_sunlock(&proctree_lock);
2008 }
2009
2010 /*
2011  * The 'hook' invoked from the kernel proper
2012  */
2013
2014
2015 #ifdef  HWPMC_DEBUG
2016 const char *pmc_hooknames[] = {
2017         /* these strings correspond to PMC_FN_* in <sys/pmckern.h> */
2018         "",
2019         "EXEC",
2020         "CSW-IN",
2021         "CSW-OUT",
2022         "SAMPLE",
2023         "UNUSED1",
2024         "UNUSED2",
2025         "MMAP",
2026         "MUNMAP",
2027         "CALLCHAIN-NMI",
2028         "CALLCHAIN-SOFT",
2029         "SOFTSAMPLING",
2030         "THR-CREATE",
2031         "THR-EXIT",
2032 };
2033 #endif
2034
2035 static int
2036 pmc_hook_handler(struct thread *td, int function, void *arg)
2037 {
2038         int cpu;
2039
2040         PMCDBG4(MOD,PMH,1, "hook td=%p func=%d \"%s\" arg=%p", td, function,
2041             pmc_hooknames[function], arg);
2042
2043         switch (function)
2044         {
2045
2046         /*
2047          * Process exec()
2048          */
2049
2050         case PMC_FN_PROCESS_EXEC:
2051         {
2052                 char *fullpath, *freepath;
2053                 unsigned int ri;
2054                 int is_using_hwpmcs;
2055                 struct pmc *pm;
2056                 struct proc *p;
2057                 struct pmc_owner *po;
2058                 struct pmc_process *pp;
2059                 struct pmckern_procexec *pk;
2060
2061                 sx_assert(&pmc_sx, SX_XLOCKED);
2062
2063                 p = td->td_proc;
2064                 pmc_getfilename(p->p_textvp, &fullpath, &freepath);
2065
2066                 pk = (struct pmckern_procexec *) arg;
2067
2068                 epoch_enter_preempt(global_epoch_preempt);
2069                 /* Inform owners of SS mode PMCs of the exec event. */
2070                 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext)
2071                     if (po->po_flags & PMC_PO_OWNS_LOGFILE)
2072                             pmclog_process_procexec(po, PMC_ID_INVALID,
2073                                 p->p_pid, pk->pm_entryaddr, fullpath);
2074                 epoch_exit_preempt(global_epoch_preempt);
2075
2076                 PROC_LOCK(p);
2077                 is_using_hwpmcs = p->p_flag & P_HWPMC;
2078                 PROC_UNLOCK(p);
2079
2080                 if (!is_using_hwpmcs) {
2081                         if (freepath)
2082                                 free(freepath, M_TEMP);
2083                         break;
2084                 }
2085
2086                 /*
2087                  * PMCs are not inherited across an exec():  remove any
2088                  * PMCs that this process is the owner of.
2089                  */
2090
2091                 if ((po = pmc_find_owner_descriptor(p)) != NULL) {
2092                         pmc_remove_owner(po);
2093                         pmc_destroy_owner_descriptor(po);
2094                 }
2095
2096                 /*
2097                  * If the process being exec'ed is not the target of any
2098                  * PMC, we are done.
2099                  */
2100                 if ((pp = pmc_find_process_descriptor(p, 0)) == NULL) {
2101                         if (freepath)
2102                                 free(freepath, M_TEMP);
2103                         break;
2104                 }
2105
2106                 /*
2107                  * Log the exec event to all monitoring owners.  Skip
2108                  * owners who have already received the event because
2109                  * they had system sampling PMCs active.
2110                  */
2111                 for (ri = 0; ri < md->pmd_npmc; ri++)
2112                         if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) {
2113                                 po = pm->pm_owner;
2114                                 if (po->po_sscount == 0 &&
2115                                     po->po_flags & PMC_PO_OWNS_LOGFILE)
2116                                         pmclog_process_procexec(po, pm->pm_id,
2117                                             p->p_pid, pk->pm_entryaddr,
2118                                             fullpath);
2119                         }
2120
2121                 if (freepath)
2122                         free(freepath, M_TEMP);
2123
2124
2125                 PMCDBG4(PRC,EXC,1, "exec proc=%p (%d, %s) cred-changed=%d",
2126                     p, p->p_pid, p->p_comm, pk->pm_credentialschanged);
2127
2128                 if (pk->pm_credentialschanged == 0) /* no change */
2129                         break;
2130
2131                 /*
2132                  * If the newly exec()'ed process has a different credential
2133                  * than before, allow it to be the target of a PMC only if
2134                  * the PMC's owner has sufficient privilege.
2135                  */
2136
2137                 for (ri = 0; ri < md->pmd_npmc; ri++)
2138                         if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL)
2139                                 if (pmc_can_attach(pm, td->td_proc) != 0)
2140                                         pmc_detach_one_process(td->td_proc,
2141                                             pm, PMC_FLAG_NONE);
2142
2143                 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt <= (int) md->pmd_npmc,
2144                     ("[pmc,%d] Illegal ref count %d on pp %p", __LINE__,
2145                         pp->pp_refcnt, pp));
2146
2147                 /*
2148                  * If this process is no longer the target of any
2149                  * PMCs, we can remove the process entry and free
2150                  * up space.
2151                  */
2152
2153                 if (pp->pp_refcnt == 0) {
2154                         pmc_remove_process_descriptor(pp);
2155                         pmc_destroy_process_descriptor(pp);
2156                         break;
2157                 }
2158
2159         }
2160         break;
2161
2162         case PMC_FN_CSW_IN:
2163                 pmc_process_csw_in(td);
2164                 break;
2165
2166         case PMC_FN_CSW_OUT:
2167                 pmc_process_csw_out(td);
2168                 break;
2169
2170         /*
2171          * Process accumulated PC samples.
2172          *
2173          * This function is expected to be called by hardclock() for
2174          * each CPU that has accumulated PC samples.
2175          *
2176          * This function is to be executed on the CPU whose samples
2177          * are being processed.
2178          */
2179         case PMC_FN_DO_SAMPLES:
2180
2181                 /*
2182                  * Clear the cpu specific bit in the CPU mask before
2183                  * do the rest of the processing.  If the NMI handler
2184                  * gets invoked after the "atomic_clear_int()" call
2185                  * below but before "pmc_process_samples()" gets
2186                  * around to processing the interrupt, then we will
2187                  * come back here at the next hardclock() tick (and
2188                  * may find nothing to do if "pmc_process_samples()"
2189                  * had already processed the interrupt).  We don't
2190                  * lose the interrupt sample.
2191                  */
2192                 DPCPU_SET(pmc_sampled, 0);
2193                 cpu = PCPU_GET(cpuid);
2194                 pmc_process_samples(cpu, PMC_HR);
2195                 pmc_process_samples(cpu, PMC_SR);
2196                 break;
2197
2198         case PMC_FN_MMAP:
2199                 MPASS(in_epoch() || sx_xlocked(&pmc_sx));
2200                 pmc_process_mmap(td, (struct pmckern_map_in *) arg);
2201                 break;
2202
2203         case PMC_FN_MUNMAP:
2204                 MPASS(in_epoch() || sx_xlocked(&pmc_sx));
2205                 pmc_process_munmap(td, (struct pmckern_map_out *) arg);
2206                 break;
2207
2208         case PMC_FN_USER_CALLCHAIN:
2209                 /*
2210                  * Record a call chain.
2211                  */
2212                 KASSERT(td == curthread, ("[pmc,%d] td != curthread",
2213                     __LINE__));
2214
2215                 pmc_capture_user_callchain(PCPU_GET(cpuid), PMC_HR,
2216                     (struct trapframe *) arg);
2217                 td->td_pflags &= ~TDP_CALLCHAIN;
2218                 break;
2219
2220         case PMC_FN_USER_CALLCHAIN_SOFT:
2221                 /*
2222                  * Record a call chain.
2223                  */
2224                 KASSERT(td == curthread, ("[pmc,%d] td != curthread",
2225                     __LINE__));
2226                 pmc_capture_user_callchain(PCPU_GET(cpuid), PMC_SR,
2227                     (struct trapframe *) arg);
2228                 td->td_pflags &= ~TDP_CALLCHAIN;
2229                 break;
2230
2231         case PMC_FN_SOFT_SAMPLING:
2232                 /*
2233                  * Call soft PMC sampling intr.
2234                  */
2235                 pmc_soft_intr((struct pmckern_soft *) arg);
2236                 break;
2237
2238         case PMC_FN_THR_CREATE:
2239                 pmc_process_thread_add(td);
2240                 break;
2241
2242         case PMC_FN_THR_EXIT:
2243                 KASSERT(td == curthread, ("[pmc,%d] td != curthread",
2244                     __LINE__));
2245                 pmc_process_thread_delete(td);
2246                 break;
2247
2248         default:
2249 #ifdef  HWPMC_DEBUG
2250                 KASSERT(0, ("[pmc,%d] unknown hook %d\n", __LINE__, function));
2251 #endif
2252                 break;
2253
2254         }
2255
2256         return 0;
2257 }
2258
2259 /*
2260  * allocate a 'struct pmc_owner' descriptor in the owner hash table.
2261  */
2262
2263 static struct pmc_owner *
2264 pmc_allocate_owner_descriptor(struct proc *p)
2265 {
2266         uint32_t hindex;
2267         struct pmc_owner *po;
2268         struct pmc_ownerhash *poh;
2269
2270         hindex = PMC_HASH_PTR(p, pmc_ownerhashmask);
2271         poh = &pmc_ownerhash[hindex];
2272
2273         /* allocate space for N pointers and one descriptor struct */
2274         po = malloc(sizeof(struct pmc_owner), M_PMC, M_WAITOK|M_ZERO);
2275         po->po_owner = p;
2276         LIST_INSERT_HEAD(poh, po, po_next); /* insert into hash table */
2277
2278         TAILQ_INIT(&po->po_logbuffers);
2279         mtx_init(&po->po_mtx, "pmc-owner-mtx", "pmc-per-proc", MTX_SPIN);
2280
2281         PMCDBG4(OWN,ALL,1, "allocate-owner proc=%p (%d, %s) pmc-owner=%p",
2282             p, p->p_pid, p->p_comm, po);
2283
2284         return po;
2285 }
2286
2287 static void
2288 pmc_destroy_owner_descriptor(struct pmc_owner *po)
2289 {
2290
2291         PMCDBG4(OWN,REL,1, "destroy-owner po=%p proc=%p (%d, %s)",
2292             po, po->po_owner, po->po_owner->p_pid, po->po_owner->p_comm);
2293
2294         mtx_destroy(&po->po_mtx);
2295         free(po, M_PMC);
2296 }
2297
2298 /*
2299  * Allocate a thread descriptor from the free pool.
2300  *
2301  * NOTE: This *can* return NULL.
2302  */
2303 static struct pmc_thread *
2304 pmc_thread_descriptor_pool_alloc(void)
2305 {
2306         struct pmc_thread *pt;
2307
2308         mtx_lock_spin(&pmc_threadfreelist_mtx);
2309         if ((pt = LIST_FIRST(&pmc_threadfreelist)) != NULL) {
2310                 LIST_REMOVE(pt, pt_next);
2311                 pmc_threadfreelist_entries--;
2312         }
2313         mtx_unlock_spin(&pmc_threadfreelist_mtx);
2314
2315         return (pt);
2316 }
2317
2318 /*
2319  * Add a thread descriptor to the free pool. We use this instead of free()
2320  * to maintain a cache of free entries. Additionally, we can safely call
2321  * this function when we cannot call free(), such as in a critical section.
2322  *
2323  */
2324 static void
2325 pmc_thread_descriptor_pool_free(struct pmc_thread *pt)
2326 {
2327
2328         if (pt == NULL)
2329                 return;
2330
2331         memset(pt, 0, THREADENTRY_SIZE);
2332         mtx_lock_spin(&pmc_threadfreelist_mtx);
2333         LIST_INSERT_HEAD(&pmc_threadfreelist, pt, pt_next);
2334         pmc_threadfreelist_entries++;
2335         if (pmc_threadfreelist_entries > pmc_threadfreelist_max)
2336                 GROUPTASK_ENQUEUE(&free_gtask);
2337         mtx_unlock_spin(&pmc_threadfreelist_mtx);
2338 }
2339
2340 /*
2341  * A callout to manage the free list.
2342  */
2343 static void
2344 pmc_thread_descriptor_pool_free_task(void *arg __unused)
2345 {
2346         struct pmc_thread *pt;
2347         LIST_HEAD(, pmc_thread) tmplist;
2348         int delta;
2349
2350         LIST_INIT(&tmplist);
2351         /* Determine what changes, if any, we need to make. */
2352         mtx_lock_spin(&pmc_threadfreelist_mtx);
2353         delta = pmc_threadfreelist_entries - pmc_threadfreelist_max;
2354         while (delta > 0 &&
2355                    (pt = LIST_FIRST(&pmc_threadfreelist)) != NULL) {
2356                 delta--;
2357                 LIST_REMOVE(pt, pt_next);
2358                 LIST_INSERT_HEAD(&tmplist, pt, pt_next);
2359         }
2360         mtx_unlock_spin(&pmc_threadfreelist_mtx);
2361
2362         /* If there are entries to free, free them. */
2363         while (!LIST_EMPTY(&tmplist)) {
2364                 pt = LIST_FIRST(&tmplist);
2365                 LIST_REMOVE(pt, pt_next);
2366                 free(pt, M_PMC);
2367         }
2368 }
2369
2370 /*
2371  * Drain the thread free pool, freeing all allocations.
2372  */
2373 static void
2374 pmc_thread_descriptor_pool_drain()
2375 {
2376         struct pmc_thread *pt, *next;
2377
2378         LIST_FOREACH_SAFE(pt, &pmc_threadfreelist, pt_next, next) {
2379                 LIST_REMOVE(pt, pt_next);
2380                 free(pt, M_PMC);
2381         }
2382 }
2383
2384 /*
2385  * find the descriptor corresponding to thread 'td', adding or removing it
2386  * as specified by 'mode'.
2387  *
2388  * Note that this supports additional mode flags in addition to those
2389  * supported by pmc_find_process_descriptor():
2390  * PMC_FLAG_NOWAIT: Causes the function to not wait for mallocs.
2391  *     This makes it safe to call while holding certain other locks.
2392  */
2393
2394 static struct pmc_thread *
2395 pmc_find_thread_descriptor(struct pmc_process *pp, struct thread *td,
2396     uint32_t mode)
2397 {
2398         struct pmc_thread *pt = NULL, *ptnew = NULL;
2399         int wait_flag;
2400
2401         KASSERT(td != NULL, ("[pmc,%d] called to add NULL td", __LINE__));
2402
2403         /*
2404          * Pre-allocate memory in the PMC_FLAG_ALLOCATE case prior to
2405          * acquiring the lock.
2406          */
2407         if (mode & PMC_FLAG_ALLOCATE) {
2408                 if ((ptnew = pmc_thread_descriptor_pool_alloc()) == NULL) {
2409                         wait_flag = M_WAITOK;
2410                         if ((mode & PMC_FLAG_NOWAIT) || in_epoch())
2411                                 wait_flag = M_NOWAIT;
2412
2413                         ptnew = malloc(THREADENTRY_SIZE, M_PMC,
2414                             wait_flag|M_ZERO);
2415                 }
2416         }
2417
2418         mtx_lock_spin(pp->pp_tdslock);
2419
2420         LIST_FOREACH(pt, &pp->pp_tds, pt_next)
2421                 if (pt->pt_td == td)
2422                         break;
2423
2424         if ((mode & PMC_FLAG_REMOVE) && pt != NULL)
2425                 LIST_REMOVE(pt, pt_next);
2426
2427         if ((mode & PMC_FLAG_ALLOCATE) && pt == NULL && ptnew != NULL) {
2428                 pt = ptnew;
2429                 ptnew = NULL;
2430                 pt->pt_td = td;
2431                 LIST_INSERT_HEAD(&pp->pp_tds, pt, pt_next);
2432         }
2433
2434         mtx_unlock_spin(pp->pp_tdslock);
2435
2436         if (ptnew != NULL) {
2437                 free(ptnew, M_PMC);
2438         }
2439
2440         return pt;
2441 }
2442
2443 /*
2444  * Try to add thread descriptors for each thread in a process.
2445  */
2446
2447 static void
2448 pmc_add_thread_descriptors_from_proc(struct proc *p, struct pmc_process *pp)
2449 {
2450         struct thread *curtd;
2451         struct pmc_thread **tdlist;
2452         int i, tdcnt, tdlistsz;
2453
2454         KASSERT(!PROC_LOCKED(p), ("[pmc,%d] proc unexpectedly locked",
2455             __LINE__));
2456         tdcnt = 32;
2457  restart:
2458         tdlistsz = roundup2(tdcnt, 32);
2459
2460         tdcnt = 0;
2461         tdlist = malloc(sizeof(struct pmc_thread*) * tdlistsz, M_TEMP, M_WAITOK);
2462
2463         PROC_LOCK(p);
2464         FOREACH_THREAD_IN_PROC(p, curtd)
2465                 tdcnt++;
2466         if (tdcnt >= tdlistsz) {
2467                 PROC_UNLOCK(p);
2468                 free(tdlist, M_TEMP);
2469                 goto restart;
2470         }
2471         /*
2472          * Try to add each thread to the list without sleeping. If unable,
2473          * add to a queue to retry after dropping the process lock.
2474          */
2475         tdcnt = 0;
2476         FOREACH_THREAD_IN_PROC(p, curtd) {
2477                 tdlist[tdcnt] = pmc_find_thread_descriptor(pp, curtd,
2478                                                    PMC_FLAG_ALLOCATE|PMC_FLAG_NOWAIT);
2479                 if (tdlist[tdcnt] == NULL) {
2480                         PROC_UNLOCK(p);
2481                         for (i = 0; i <= tdcnt; i++)
2482                                 pmc_thread_descriptor_pool_free(tdlist[i]);
2483                         free(tdlist, M_TEMP);
2484                         goto restart;
2485                 }
2486                 tdcnt++;
2487         }
2488         PROC_UNLOCK(p);
2489         free(tdlist, M_TEMP);
2490 }
2491
2492 /*
2493  * find the descriptor corresponding to process 'p', adding or removing it
2494  * as specified by 'mode'.
2495  */
2496
2497 static struct pmc_process *
2498 pmc_find_process_descriptor(struct proc *p, uint32_t mode)
2499 {
2500         uint32_t hindex;
2501         struct pmc_process *pp, *ppnew;
2502         struct pmc_processhash *pph;
2503
2504         hindex = PMC_HASH_PTR(p, pmc_processhashmask);
2505         pph = &pmc_processhash[hindex];
2506
2507         ppnew = NULL;
2508
2509         /*
2510          * Pre-allocate memory in the PMC_FLAG_ALLOCATE case since we
2511          * cannot call malloc(9) once we hold a spin lock.
2512          */
2513         if (mode & PMC_FLAG_ALLOCATE)
2514                 ppnew = malloc(sizeof(struct pmc_process) + md->pmd_npmc *
2515                     sizeof(struct pmc_targetstate), M_PMC, M_WAITOK|M_ZERO);
2516
2517         mtx_lock_spin(&pmc_processhash_mtx);
2518         LIST_FOREACH(pp, pph, pp_next)
2519             if (pp->pp_proc == p)
2520                     break;
2521
2522         if ((mode & PMC_FLAG_REMOVE) && pp != NULL)
2523                 LIST_REMOVE(pp, pp_next);
2524
2525         if ((mode & PMC_FLAG_ALLOCATE) && pp == NULL &&
2526             ppnew != NULL) {
2527                 ppnew->pp_proc = p;
2528                 LIST_INIT(&ppnew->pp_tds);
2529                 ppnew->pp_tdslock = mtx_pool_find(pmc_mtxpool, ppnew);
2530                 LIST_INSERT_HEAD(pph, ppnew, pp_next);
2531                 mtx_unlock_spin(&pmc_processhash_mtx);
2532                 pp = ppnew;
2533                 ppnew = NULL;
2534
2535                 /* Add thread descriptors for this process' current threads. */
2536                 pmc_add_thread_descriptors_from_proc(p, pp);
2537         }
2538         else
2539                 mtx_unlock_spin(&pmc_processhash_mtx);
2540
2541         if (ppnew != NULL)
2542                 free(ppnew, M_PMC);
2543
2544         return pp;
2545 }
2546
2547 /*
2548  * remove a process descriptor from the process hash table.
2549  */
2550
2551 static void
2552 pmc_remove_process_descriptor(struct pmc_process *pp)
2553 {
2554         KASSERT(pp->pp_refcnt == 0,
2555             ("[pmc,%d] Removing process descriptor %p with count %d",
2556                 __LINE__, pp, pp->pp_refcnt));
2557
2558         mtx_lock_spin(&pmc_processhash_mtx);
2559         LIST_REMOVE(pp, pp_next);
2560         mtx_unlock_spin(&pmc_processhash_mtx);
2561 }
2562
2563 /*
2564  * destroy a process descriptor.
2565  */
2566
2567 static void
2568 pmc_destroy_process_descriptor(struct pmc_process *pp)
2569 {
2570         struct pmc_thread *pmc_td;
2571
2572         while ((pmc_td = LIST_FIRST(&pp->pp_tds)) != NULL) {
2573                 LIST_REMOVE(pmc_td, pt_next);
2574                 pmc_thread_descriptor_pool_free(pmc_td);
2575         }
2576         free(pp, M_PMC);
2577 }
2578
2579
2580 /*
2581  * find an owner descriptor corresponding to proc 'p'
2582  */
2583
2584 static struct pmc_owner *
2585 pmc_find_owner_descriptor(struct proc *p)
2586 {
2587         uint32_t hindex;
2588         struct pmc_owner *po;
2589         struct pmc_ownerhash *poh;
2590
2591         hindex = PMC_HASH_PTR(p, pmc_ownerhashmask);
2592         poh = &pmc_ownerhash[hindex];
2593
2594         po = NULL;
2595         LIST_FOREACH(po, poh, po_next)
2596             if (po->po_owner == p)
2597                     break;
2598
2599         PMCDBG5(OWN,FND,1, "find-owner proc=%p (%d, %s) hindex=0x%x -> "
2600             "pmc-owner=%p", p, p->p_pid, p->p_comm, hindex, po);
2601
2602         return po;
2603 }
2604
2605 /*
2606  * pmc_allocate_pmc_descriptor
2607  *
2608  * Allocate a pmc descriptor and initialize its
2609  * fields.
2610  */
2611
2612 static struct pmc *
2613 pmc_allocate_pmc_descriptor(void)
2614 {
2615         struct pmc *pmc;
2616
2617         pmc = malloc(sizeof(struct pmc), M_PMC, M_WAITOK|M_ZERO);
2618         pmc->pm_runcount = counter_u64_alloc(M_WAITOK);
2619         pmc->pm_pcpu_state = malloc(sizeof(struct pmc_pcpu_state)*mp_ncpus, M_PMC, M_WAITOK|M_ZERO);
2620         PMCDBG1(PMC,ALL,1, "allocate-pmc -> pmc=%p", pmc);
2621
2622         return pmc;
2623 }
2624
2625 /*
2626  * Destroy a pmc descriptor.
2627  */
2628
2629 static void
2630 pmc_destroy_pmc_descriptor(struct pmc *pm)
2631 {
2632
2633         KASSERT(pm->pm_state == PMC_STATE_DELETED ||
2634             pm->pm_state == PMC_STATE_FREE,
2635             ("[pmc,%d] destroying non-deleted PMC", __LINE__));
2636         KASSERT(LIST_EMPTY(&pm->pm_targets),
2637             ("[pmc,%d] destroying pmc with targets", __LINE__));
2638         KASSERT(pm->pm_owner == NULL,
2639             ("[pmc,%d] destroying pmc attached to an owner", __LINE__));
2640         KASSERT(counter_u64_fetch(pm->pm_runcount) == 0,
2641             ("[pmc,%d] pmc has non-zero run count %ld", __LINE__,
2642                  (unsigned long)counter_u64_fetch(pm->pm_runcount)));
2643
2644         counter_u64_free(pm->pm_runcount);
2645         free(pm->pm_pcpu_state, M_PMC);
2646         free(pm, M_PMC);
2647 }
2648
2649 static void
2650 pmc_wait_for_pmc_idle(struct pmc *pm)
2651 {
2652 #ifdef HWPMC_DEBUG
2653         volatile int maxloop;
2654
2655         maxloop = 100 * pmc_cpu_max();
2656 #endif
2657         /*
2658          * Loop (with a forced context switch) till the PMC's runcount
2659          * comes down to zero.
2660          */
2661         while (counter_u64_fetch(pm->pm_runcount) > 0) {
2662 #ifdef HWPMC_DEBUG
2663                 maxloop--;
2664                 KASSERT(maxloop > 0,
2665                     ("[pmc,%d] (ri%d, rc%ld) waiting too long for "
2666                         "pmc to be free", __LINE__,
2667                          PMC_TO_ROWINDEX(pm), (unsigned long)counter_u64_fetch(pm->pm_runcount)));
2668 #endif
2669                 pmc_force_context_switch();
2670         }
2671 }
2672
2673 /*
2674  * This function does the following things:
2675  *
2676  *  - detaches the PMC from hardware
2677  *  - unlinks all target threads that were attached to it
2678  *  - removes the PMC from its owner's list
2679  *  - destroys the PMC private mutex
2680  *
2681  * Once this function completes, the given pmc pointer can be freed by
2682  * calling pmc_destroy_pmc_descriptor().
2683  */
2684
2685 static void
2686 pmc_release_pmc_descriptor(struct pmc *pm)
2687 {
2688         enum pmc_mode mode;
2689         struct pmc_hw *phw;
2690         u_int adjri, ri, cpu;
2691         struct pmc_owner *po;
2692         struct pmc_binding pb;
2693         struct pmc_process *pp;
2694         struct pmc_classdep *pcd;
2695         struct pmc_target *ptgt, *tmp;
2696
2697         sx_assert(&pmc_sx, SX_XLOCKED);
2698
2699         KASSERT(pm, ("[pmc,%d] null pmc", __LINE__));
2700
2701         ri   = PMC_TO_ROWINDEX(pm);
2702         pcd  = pmc_ri_to_classdep(md, ri, &adjri);
2703         mode = PMC_TO_MODE(pm);
2704
2705         PMCDBG3(PMC,REL,1, "release-pmc pmc=%p ri=%d mode=%d", pm, ri,
2706             mode);
2707
2708         /*
2709          * First, we take the PMC off hardware.
2710          */
2711         cpu = 0;
2712         if (PMC_IS_SYSTEM_MODE(mode)) {
2713
2714                 /*
2715                  * A system mode PMC runs on a specific CPU.  Switch
2716                  * to this CPU and turn hardware off.
2717                  */
2718                 pmc_save_cpu_binding(&pb);
2719
2720                 cpu = PMC_TO_CPU(pm);
2721
2722                 pmc_select_cpu(cpu);
2723
2724                 /* switch off non-stalled CPUs */
2725                 pm->pm_pcpu_state[cpu].pps_cpustate = 0;
2726                 if (pm->pm_state == PMC_STATE_RUNNING &&
2727                         pm->pm_pcpu_state[cpu].pps_stalled == 0) {
2728
2729                         phw = pmc_pcpu[cpu]->pc_hwpmcs[ri];
2730
2731                         KASSERT(phw->phw_pmc == pm,
2732                             ("[pmc, %d] pmc ptr ri(%d) hw(%p) pm(%p)",
2733                                 __LINE__, ri, phw->phw_pmc, pm));
2734                         PMCDBG2(PMC,REL,2, "stopping cpu=%d ri=%d", cpu, ri);
2735
2736                         critical_enter();
2737                         pcd->pcd_stop_pmc(cpu, adjri);
2738                         critical_exit();
2739                 }
2740
2741                 PMCDBG2(PMC,REL,2, "decfg cpu=%d ri=%d", cpu, ri);
2742
2743                 critical_enter();
2744                 pcd->pcd_config_pmc(cpu, adjri, NULL);
2745                 critical_exit();
2746
2747                 /* adjust the global and process count of SS mode PMCs */
2748                 if (mode == PMC_MODE_SS && pm->pm_state == PMC_STATE_RUNNING) {
2749                         po = pm->pm_owner;
2750                         po->po_sscount--;
2751                         if (po->po_sscount == 0) {
2752                                 atomic_subtract_rel_int(&pmc_ss_count, 1);
2753                                 CK_LIST_REMOVE(po, po_ssnext);
2754                                 epoch_wait_preempt(global_epoch_preempt);
2755                         }
2756                 }
2757
2758                 pm->pm_state = PMC_STATE_DELETED;
2759
2760                 pmc_restore_cpu_binding(&pb);
2761
2762                 /*
2763                  * We could have references to this PMC structure in
2764                  * the per-cpu sample queues.  Wait for the queue to
2765                  * drain.
2766                  */
2767                 pmc_wait_for_pmc_idle(pm);
2768
2769         } else if (PMC_IS_VIRTUAL_MODE(mode)) {
2770
2771                 /*
2772                  * A virtual PMC could be running on multiple CPUs at
2773                  * a given instant.
2774                  *
2775                  * By marking its state as DELETED, we ensure that
2776                  * this PMC is never further scheduled on hardware.
2777                  *
2778                  * Then we wait till all CPUs are done with this PMC.
2779                  */
2780                 pm->pm_state = PMC_STATE_DELETED;
2781
2782
2783                 /* Wait for the PMCs runcount to come to zero. */
2784                 pmc_wait_for_pmc_idle(pm);
2785
2786                 /*
2787                  * At this point the PMC is off all CPUs and cannot be
2788                  * freshly scheduled onto a CPU.  It is now safe to
2789                  * unlink all targets from this PMC.  If a
2790                  * process-record's refcount falls to zero, we remove
2791                  * it from the hash table.  The module-wide SX lock
2792                  * protects us from races.
2793                  */
2794                 LIST_FOREACH_SAFE(ptgt, &pm->pm_targets, pt_next, tmp) {
2795                         pp = ptgt->pt_process;
2796                         pmc_unlink_target_process(pm, pp); /* frees 'ptgt' */
2797
2798                         PMCDBG1(PMC,REL,3, "pp->refcnt=%d", pp->pp_refcnt);
2799
2800                         /*
2801                          * If the target process record shows that no
2802                          * PMCs are attached to it, reclaim its space.
2803                          */
2804
2805                         if (pp->pp_refcnt == 0) {
2806                                 pmc_remove_process_descriptor(pp);
2807                                 pmc_destroy_process_descriptor(pp);
2808                         }
2809                 }
2810
2811                 cpu = curthread->td_oncpu; /* setup cpu for pmd_release() */
2812
2813         }
2814
2815         /*
2816          * Release any MD resources
2817          */
2818         (void) pcd->pcd_release_pmc(cpu, adjri, pm);
2819
2820         /*
2821          * Update row disposition
2822          */
2823
2824         if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pm)))
2825                 PMC_UNMARK_ROW_STANDALONE(ri);
2826         else
2827                 PMC_UNMARK_ROW_THREAD(ri);
2828
2829         /* unlink from the owner's list */
2830         if (pm->pm_owner) {
2831                 LIST_REMOVE(pm, pm_next);
2832                 pm->pm_owner = NULL;
2833         }
2834 }
2835
2836 /*
2837  * Register an owner and a pmc.
2838  */
2839
2840 static int
2841 pmc_register_owner(struct proc *p, struct pmc *pmc)
2842 {
2843         struct pmc_owner *po;
2844
2845         sx_assert(&pmc_sx, SX_XLOCKED);
2846
2847         if ((po = pmc_find_owner_descriptor(p)) == NULL)
2848                 if ((po = pmc_allocate_owner_descriptor(p)) == NULL)
2849                         return ENOMEM;
2850
2851         KASSERT(pmc->pm_owner == NULL,
2852             ("[pmc,%d] attempting to own an initialized PMC", __LINE__));
2853         pmc->pm_owner  = po;
2854
2855         LIST_INSERT_HEAD(&po->po_pmcs, pmc, pm_next);
2856
2857         PROC_LOCK(p);
2858         p->p_flag |= P_HWPMC;
2859         PROC_UNLOCK(p);
2860
2861         if (po->po_flags & PMC_PO_OWNS_LOGFILE)
2862                 pmclog_process_pmcallocate(pmc);
2863
2864         PMCDBG2(PMC,REG,1, "register-owner pmc-owner=%p pmc=%p",
2865             po, pmc);
2866
2867         return 0;
2868 }
2869
2870 /*
2871  * Return the current row disposition:
2872  * == 0 => FREE
2873  *  > 0 => PROCESS MODE
2874  *  < 0 => SYSTEM MODE
2875  */
2876
2877 int
2878 pmc_getrowdisp(int ri)
2879 {
2880         return pmc_pmcdisp[ri];
2881 }
2882
2883 /*
2884  * Check if a PMC at row index 'ri' can be allocated to the current
2885  * process.
2886  *
2887  * Allocation can fail if:
2888  *   - the current process is already being profiled by a PMC at index 'ri',
2889  *     attached to it via OP_PMCATTACH.
2890  *   - the current process has already allocated a PMC at index 'ri'
2891  *     via OP_ALLOCATE.
2892  */
2893
2894 static int
2895 pmc_can_allocate_rowindex(struct proc *p, unsigned int ri, int cpu)
2896 {
2897         enum pmc_mode mode;
2898         struct pmc *pm;
2899         struct pmc_owner *po;
2900         struct pmc_process *pp;
2901
2902         PMCDBG5(PMC,ALR,1, "can-allocate-rowindex proc=%p (%d, %s) ri=%d "
2903             "cpu=%d", p, p->p_pid, p->p_comm, ri, cpu);
2904
2905         /*
2906          * We shouldn't have already allocated a process-mode PMC at
2907          * row index 'ri'.
2908          *
2909          * We shouldn't have allocated a system-wide PMC on the same
2910          * CPU and same RI.
2911          */
2912         if ((po = pmc_find_owner_descriptor(p)) != NULL)
2913                 LIST_FOREACH(pm, &po->po_pmcs, pm_next) {
2914                     if (PMC_TO_ROWINDEX(pm) == ri) {
2915                             mode = PMC_TO_MODE(pm);
2916                             if (PMC_IS_VIRTUAL_MODE(mode))
2917                                     return EEXIST;
2918                             if (PMC_IS_SYSTEM_MODE(mode) &&
2919                                 (int) PMC_TO_CPU(pm) == cpu)
2920                                     return EEXIST;
2921                     }
2922                 }
2923
2924         /*
2925          * We also shouldn't be the target of any PMC at this index
2926          * since otherwise a PMC_ATTACH to ourselves will fail.
2927          */
2928         if ((pp = pmc_find_process_descriptor(p, 0)) != NULL)
2929                 if (pp->pp_pmcs[ri].pp_pmc)
2930                         return EEXIST;
2931
2932         PMCDBG4(PMC,ALR,2, "can-allocate-rowindex proc=%p (%d, %s) ri=%d ok",
2933             p, p->p_pid, p->p_comm, ri);
2934
2935         return 0;
2936 }
2937
2938 /*
2939  * Check if a given PMC at row index 'ri' can be currently used in
2940  * mode 'mode'.
2941  */
2942
2943 static int
2944 pmc_can_allocate_row(int ri, enum pmc_mode mode)
2945 {
2946         enum pmc_disp   disp;
2947
2948         sx_assert(&pmc_sx, SX_XLOCKED);
2949
2950         PMCDBG2(PMC,ALR,1, "can-allocate-row ri=%d mode=%d", ri, mode);
2951
2952         if (PMC_IS_SYSTEM_MODE(mode))
2953                 disp = PMC_DISP_STANDALONE;
2954         else
2955                 disp = PMC_DISP_THREAD;
2956
2957         /*
2958          * check disposition for PMC row 'ri':
2959          *
2960          * Expected disposition         Row-disposition         Result
2961          *
2962          * STANDALONE                   STANDALONE or FREE      proceed
2963          * STANDALONE                   THREAD                  fail
2964          * THREAD                       THREAD or FREE          proceed
2965          * THREAD                       STANDALONE              fail
2966          */
2967
2968         if (!PMC_ROW_DISP_IS_FREE(ri) &&
2969             !(disp == PMC_DISP_THREAD && PMC_ROW_DISP_IS_THREAD(ri)) &&
2970             !(disp == PMC_DISP_STANDALONE && PMC_ROW_DISP_IS_STANDALONE(ri)))
2971                 return EBUSY;
2972
2973         /*
2974          * All OK
2975          */
2976
2977         PMCDBG2(PMC,ALR,2, "can-allocate-row ri=%d mode=%d ok", ri, mode);
2978
2979         return 0;
2980
2981 }
2982
2983 /*
2984  * Find a PMC descriptor with user handle 'pmcid' for thread 'td'.
2985  */
2986
2987 static struct pmc *
2988 pmc_find_pmc_descriptor_in_process(struct pmc_owner *po, pmc_id_t pmcid)
2989 {
2990         struct pmc *pm;
2991
2992         KASSERT(PMC_ID_TO_ROWINDEX(pmcid) < md->pmd_npmc,
2993             ("[pmc,%d] Illegal pmc index %d (max %d)", __LINE__,
2994                 PMC_ID_TO_ROWINDEX(pmcid), md->pmd_npmc));
2995
2996         LIST_FOREACH(pm, &po->po_pmcs, pm_next)
2997             if (pm->pm_id == pmcid)
2998                     return pm;
2999
3000         return NULL;
3001 }
3002
3003 static int
3004 pmc_find_pmc(pmc_id_t pmcid, struct pmc **pmc)
3005 {
3006
3007         struct pmc *pm, *opm;
3008         struct pmc_owner *po;
3009         struct pmc_process *pp;
3010
3011         PMCDBG1(PMC,FND,1, "find-pmc id=%d", pmcid);
3012         if (PMC_ID_TO_ROWINDEX(pmcid) >= md->pmd_npmc)
3013                 return (EINVAL);
3014
3015         if ((po = pmc_find_owner_descriptor(curthread->td_proc)) == NULL) {
3016                 /*
3017                  * In case of PMC_F_DESCENDANTS child processes we will not find
3018                  * the current process in the owners hash list.  Find the owner
3019                  * process first and from there lookup the po.
3020                  */
3021                 if ((pp = pmc_find_process_descriptor(curthread->td_proc,
3022                     PMC_FLAG_NONE)) == NULL) {
3023                         return ESRCH;
3024                 } else {
3025                         opm = pp->pp_pmcs[PMC_ID_TO_ROWINDEX(pmcid)].pp_pmc;
3026                         if (opm == NULL)
3027                                 return ESRCH;
3028                         if ((opm->pm_flags & (PMC_F_ATTACHED_TO_OWNER|
3029                             PMC_F_DESCENDANTS)) != (PMC_F_ATTACHED_TO_OWNER|
3030                             PMC_F_DESCENDANTS))
3031                                 return ESRCH;
3032                         po = opm->pm_owner;
3033                 }
3034         }
3035
3036         if ((pm = pmc_find_pmc_descriptor_in_process(po, pmcid)) == NULL)
3037                 return EINVAL;
3038
3039         PMCDBG2(PMC,FND,2, "find-pmc id=%d -> pmc=%p", pmcid, pm);
3040
3041         *pmc = pm;
3042         return 0;
3043 }
3044
3045 /*
3046  * Start a PMC.
3047  */
3048
3049 static int
3050 pmc_start(struct pmc *pm)
3051 {
3052         enum pmc_mode mode;
3053         struct pmc_owner *po;
3054         struct pmc_binding pb;
3055         struct pmc_classdep *pcd;
3056         int adjri, error, cpu, ri;
3057
3058         KASSERT(pm != NULL,
3059             ("[pmc,%d] null pm", __LINE__));
3060
3061         mode = PMC_TO_MODE(pm);
3062         ri   = PMC_TO_ROWINDEX(pm);
3063         pcd  = pmc_ri_to_classdep(md, ri, &adjri);
3064
3065         error = 0;
3066
3067         PMCDBG3(PMC,OPS,1, "start pmc=%p mode=%d ri=%d", pm, mode, ri);
3068
3069         po = pm->pm_owner;
3070
3071         /*
3072          * Disallow PMCSTART if a logfile is required but has not been
3073          * configured yet.
3074          */
3075         if ((pm->pm_flags & PMC_F_NEEDS_LOGFILE) &&
3076             (po->po_flags & PMC_PO_OWNS_LOGFILE) == 0)
3077                 return (EDOOFUS);       /* programming error */
3078
3079         /*
3080          * If this is a sampling mode PMC, log mapping information for
3081          * the kernel modules that are currently loaded.
3082          */
3083         if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)))
3084             pmc_log_kernel_mappings(pm);
3085
3086         if (PMC_IS_VIRTUAL_MODE(mode)) {
3087
3088                 /*
3089                  * If a PMCATTACH has never been done on this PMC,
3090                  * attach it to its owner process.
3091                  */
3092
3093                 if (LIST_EMPTY(&pm->pm_targets))
3094                         error = (pm->pm_flags & PMC_F_ATTACH_DONE) ? ESRCH :
3095                             pmc_attach_process(po->po_owner, pm);
3096
3097                 /*
3098                  * If the PMC is attached to its owner, then force a context
3099                  * switch to ensure that the MD state gets set correctly.
3100                  */
3101
3102                 if (error == 0) {
3103                         pm->pm_state = PMC_STATE_RUNNING;
3104                         if (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER)
3105                                 pmc_force_context_switch();
3106                 }
3107
3108                 return (error);
3109         }
3110
3111
3112         /*
3113          * A system-wide PMC.
3114          *
3115          * Add the owner to the global list if this is a system-wide
3116          * sampling PMC.
3117          */
3118
3119         if (mode == PMC_MODE_SS) {
3120                 /*
3121                  * Log mapping information for all existing processes in the
3122                  * system.  Subsequent mappings are logged as they happen;
3123                  * see pmc_process_mmap().
3124                  */
3125                 if (po->po_logprocmaps == 0) {
3126                         pmc_log_all_process_mappings(po);
3127                         po->po_logprocmaps = 1;
3128                 }
3129                 po->po_sscount++;
3130                 if (po->po_sscount == 1) {
3131                         atomic_add_rel_int(&pmc_ss_count, 1);
3132                         CK_LIST_INSERT_HEAD(&pmc_ss_owners, po, po_ssnext);
3133                         PMCDBG1(PMC,OPS,1, "po=%p in global list", po);
3134                 }
3135         }
3136
3137         /*
3138          * Move to the CPU associated with this
3139          * PMC, and start the hardware.
3140          */
3141
3142         pmc_save_cpu_binding(&pb);
3143
3144         cpu = PMC_TO_CPU(pm);
3145
3146         if (!pmc_cpu_is_active(cpu))
3147                 return (ENXIO);
3148
3149         pmc_select_cpu(cpu);
3150
3151         /*
3152          * global PMCs are configured at allocation time
3153          * so write out the initial value and start the PMC.
3154          */
3155
3156         pm->pm_state = PMC_STATE_RUNNING;
3157
3158         critical_enter();
3159         if ((error = pcd->pcd_write_pmc(cpu, adjri,
3160                  PMC_IS_SAMPLING_MODE(mode) ?
3161                  pm->pm_sc.pm_reloadcount :
3162                  pm->pm_sc.pm_initial)) == 0) {
3163                 /* If a sampling mode PMC, reset stalled state. */
3164                 if (PMC_IS_SAMPLING_MODE(mode))
3165                         pm->pm_pcpu_state[cpu].pps_stalled = 0;
3166
3167                 /* Indicate that we desire this to run. Start it. */
3168                 pm->pm_pcpu_state[cpu].pps_cpustate = 1;
3169                 error = pcd->pcd_start_pmc(cpu, adjri);
3170         }
3171         critical_exit();
3172
3173         pmc_restore_cpu_binding(&pb);
3174
3175         return (error);
3176 }
3177
3178 /*
3179  * Stop a PMC.
3180  */
3181
3182 static int
3183 pmc_stop(struct pmc *pm)
3184 {
3185         struct pmc_owner *po;
3186         struct pmc_binding pb;
3187         struct pmc_classdep *pcd;
3188         int adjri, cpu, error, ri;
3189
3190         KASSERT(pm != NULL, ("[pmc,%d] null pmc", __LINE__));
3191
3192         PMCDBG3(PMC,OPS,1, "stop pmc=%p mode=%d ri=%d", pm,
3193             PMC_TO_MODE(pm), PMC_TO_ROWINDEX(pm));
3194
3195         pm->pm_state = PMC_STATE_STOPPED;
3196
3197         /*
3198          * If the PMC is a virtual mode one, changing the state to
3199          * non-RUNNING is enough to ensure that the PMC never gets
3200          * scheduled.
3201          *
3202          * If this PMC is current running on a CPU, then it will
3203          * handled correctly at the time its target process is context
3204          * switched out.
3205          */
3206
3207         if (PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)))
3208                 return 0;
3209
3210         /*
3211          * A system-mode PMC.  Move to the CPU associated with
3212          * this PMC, and stop the hardware.  We update the
3213          * 'initial count' so that a subsequent PMCSTART will
3214          * resume counting from the current hardware count.
3215          */
3216
3217         pmc_save_cpu_binding(&pb);
3218
3219         cpu = PMC_TO_CPU(pm);
3220
3221         KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
3222             ("[pmc,%d] illegal cpu=%d", __LINE__, cpu));
3223
3224         if (!pmc_cpu_is_active(cpu))
3225                 return ENXIO;
3226
3227         pmc_select_cpu(cpu);
3228
3229         ri = PMC_TO_ROWINDEX(pm);
3230         pcd = pmc_ri_to_classdep(md, ri, &adjri);
3231
3232         pm->pm_pcpu_state[cpu].pps_cpustate = 0;
3233         critical_enter();
3234         if ((error = pcd->pcd_stop_pmc(cpu, adjri)) == 0)
3235                 error = pcd->pcd_read_pmc(cpu, adjri, &pm->pm_sc.pm_initial);
3236         critical_exit();
3237
3238         pmc_restore_cpu_binding(&pb);
3239
3240         po = pm->pm_owner;
3241
3242         /* remove this owner from the global list of SS PMC owners */
3243         if (PMC_TO_MODE(pm) == PMC_MODE_SS) {
3244                 po->po_sscount--;
3245                 if (po->po_sscount == 0) {
3246                         atomic_subtract_rel_int(&pmc_ss_count, 1);
3247                         CK_LIST_REMOVE(po, po_ssnext);
3248                         epoch_wait_preempt(global_epoch_preempt);
3249                         PMCDBG1(PMC,OPS,2,"po=%p removed from global list", po);
3250                 }
3251         }
3252
3253         return (error);
3254 }
3255
3256 static struct pmc_classdep *
3257 pmc_class_to_classdep(enum pmc_class class)
3258 {
3259         int n;
3260
3261         for (n = 0; n < md->pmd_nclass; n++)
3262                 if (md->pmd_classdep[n].pcd_class == class)
3263                         return (&md->pmd_classdep[n]);
3264         return (NULL);
3265 }
3266
3267 #ifdef  HWPMC_DEBUG
3268 static const char *pmc_op_to_name[] = {
3269 #undef  __PMC_OP
3270 #define __PMC_OP(N, D)  #N ,
3271         __PMC_OPS()
3272         NULL
3273 };
3274 #endif
3275
3276 /*
3277  * The syscall interface
3278  */
3279
3280 #define PMC_GET_SX_XLOCK(...) do {              \
3281         sx_xlock(&pmc_sx);                      \
3282         if (pmc_hook == NULL) {                 \
3283                 sx_xunlock(&pmc_sx);            \
3284                 return __VA_ARGS__;             \
3285         }                                       \
3286 } while (0)
3287
3288 #define PMC_DOWNGRADE_SX() do {                 \
3289         sx_downgrade(&pmc_sx);                  \
3290         is_sx_downgraded = 1;                   \
3291 } while (0)
3292
3293 static int
3294 pmc_syscall_handler(struct thread *td, void *syscall_args)
3295 {
3296         int error, is_sx_downgraded, op;
3297         struct pmc_syscall_args *c;
3298         void *pmclog_proc_handle;
3299         void *arg;
3300
3301         c = (struct pmc_syscall_args *)syscall_args;
3302         op = c->pmop_code;
3303         arg = c->pmop_data;
3304         /* PMC isn't set up yet */
3305         if (pmc_hook == NULL)
3306                 return (EINVAL);
3307         if (op == PMC_OP_CONFIGURELOG) {
3308                 /*
3309                  * We cannot create the logging process inside
3310                  * pmclog_configure_log() because there is a LOR
3311                  * between pmc_sx and process structure locks.
3312                  * Instead, pre-create the process and ignite the loop
3313                  * if everything is fine, otherwise direct the process
3314                  * to exit.
3315                  */
3316                 error = pmclog_proc_create(td, &pmclog_proc_handle);
3317                 if (error != 0)
3318                         goto done_syscall;
3319         }
3320
3321         PMC_GET_SX_XLOCK(ENOSYS);
3322         is_sx_downgraded = 0;
3323         PMCDBG3(MOD,PMS,1, "syscall op=%d \"%s\" arg=%p", op,
3324             pmc_op_to_name[op], arg);
3325
3326         error = 0;
3327         counter_u64_add(pmc_stats.pm_syscalls, 1);
3328
3329         switch (op) {
3330
3331
3332         /*
3333          * Configure a log file.
3334          *
3335          * XXX This OP will be reworked.
3336          */
3337
3338         case PMC_OP_CONFIGURELOG:
3339         {
3340                 struct proc *p;
3341                 struct pmc *pm;
3342                 struct pmc_owner *po;
3343                 struct pmc_op_configurelog cl;
3344
3345                 if ((error = copyin(arg, &cl, sizeof(cl))) != 0) {
3346                         pmclog_proc_ignite(pmclog_proc_handle, NULL);
3347                         break;
3348                 }
3349
3350                 /* mark this process as owning a log file */
3351                 p = td->td_proc;
3352                 if ((po = pmc_find_owner_descriptor(p)) == NULL)
3353                         if ((po = pmc_allocate_owner_descriptor(p)) == NULL) {
3354                                 pmclog_proc_ignite(pmclog_proc_handle, NULL);
3355                                 error = ENOMEM;
3356                                 break;
3357                         }
3358
3359                 /*
3360                  * If a valid fd was passed in, try to configure that,
3361                  * otherwise if 'fd' was less than zero and there was
3362                  * a log file configured, flush its buffers and
3363                  * de-configure it.
3364                  */
3365                 if (cl.pm_logfd >= 0) {
3366                         error = pmclog_configure_log(md, po, cl.pm_logfd);
3367                         pmclog_proc_ignite(pmclog_proc_handle, error == 0 ?
3368                             po : NULL);
3369                 } else if (po->po_flags & PMC_PO_OWNS_LOGFILE) {
3370                         pmclog_proc_ignite(pmclog_proc_handle, NULL);
3371                         error = pmclog_close(po);
3372                         if (error == 0) {
3373                                 LIST_FOREACH(pm, &po->po_pmcs, pm_next)
3374                                     if (pm->pm_flags & PMC_F_NEEDS_LOGFILE &&
3375                                         pm->pm_state == PMC_STATE_RUNNING)
3376                                             pmc_stop(pm);
3377                                 error = pmclog_deconfigure_log(po);
3378                         }
3379                 } else {
3380                         pmclog_proc_ignite(pmclog_proc_handle, NULL);
3381                         error = EINVAL;
3382                 }
3383         }
3384         break;
3385
3386         /*
3387          * Flush a log file.
3388          */
3389
3390         case PMC_OP_FLUSHLOG:
3391         {
3392                 struct pmc_owner *po;
3393
3394                 sx_assert(&pmc_sx, SX_XLOCKED);
3395
3396                 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) {
3397                         error = EINVAL;
3398                         break;
3399                 }
3400
3401                 error = pmclog_flush(po);
3402         }
3403         break;
3404
3405         /*
3406          * Close a log file.
3407          */
3408
3409         case PMC_OP_CLOSELOG:
3410         {
3411                 struct pmc_owner *po;
3412
3413                 sx_assert(&pmc_sx, SX_XLOCKED);
3414
3415                 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) {
3416                         error = EINVAL;
3417                         break;
3418                 }
3419
3420                 error = pmclog_close(po);
3421         }
3422         break;
3423
3424         /*
3425          * Retrieve hardware configuration.
3426          */
3427
3428         case PMC_OP_GETCPUINFO: /* CPU information */
3429         {
3430                 struct pmc_op_getcpuinfo gci;
3431                 struct pmc_classinfo *pci;
3432                 struct pmc_classdep *pcd;
3433                 int cl;
3434
3435                 gci.pm_cputype = md->pmd_cputype;
3436                 gci.pm_ncpu    = pmc_cpu_max();
3437                 gci.pm_npmc    = md->pmd_npmc;
3438                 gci.pm_nclass  = md->pmd_nclass;
3439                 pci = gci.pm_classes;
3440                 pcd = md->pmd_classdep;
3441                 for (cl = 0; cl < md->pmd_nclass; cl++, pci++, pcd++) {
3442                         pci->pm_caps  = pcd->pcd_caps;
3443                         pci->pm_class = pcd->pcd_class;
3444                         pci->pm_width = pcd->pcd_width;
3445                         pci->pm_num   = pcd->pcd_num;
3446                 }
3447                 error = copyout(&gci, arg, sizeof(gci));
3448         }
3449         break;
3450
3451         /*
3452          * Retrieve soft events list.
3453          */
3454         case PMC_OP_GETDYNEVENTINFO:
3455         {
3456                 enum pmc_class                  cl;
3457                 enum pmc_event                  ev;
3458                 struct pmc_op_getdyneventinfo   *gei;
3459                 struct pmc_dyn_event_descr      dev;
3460                 struct pmc_soft                 *ps;
3461                 uint32_t                        nevent;
3462
3463                 sx_assert(&pmc_sx, SX_LOCKED);
3464
3465                 gei = (struct pmc_op_getdyneventinfo *) arg;
3466
3467                 if ((error = copyin(&gei->pm_class, &cl, sizeof(cl))) != 0)
3468                         break;
3469
3470                 /* Only SOFT class is dynamic. */
3471                 if (cl != PMC_CLASS_SOFT) {
3472                         error = EINVAL;
3473                         break;
3474                 }
3475
3476                 nevent = 0;
3477                 for (ev = PMC_EV_SOFT_FIRST; (int)ev <= PMC_EV_SOFT_LAST; ev++) {
3478                         ps = pmc_soft_ev_acquire(ev);
3479                         if (ps == NULL)
3480                                 continue;
3481                         bcopy(&ps->ps_ev, &dev, sizeof(dev));
3482                         pmc_soft_ev_release(ps);
3483
3484                         error = copyout(&dev,
3485                             &gei->pm_events[nevent],
3486                             sizeof(struct pmc_dyn_event_descr));
3487                         if (error != 0)
3488                                 break;
3489                         nevent++;
3490                 }
3491                 if (error != 0)
3492                         break;
3493
3494                 error = copyout(&nevent, &gei->pm_nevent,
3495                     sizeof(nevent));
3496         }
3497         break;
3498
3499         /*
3500          * Get module statistics
3501          */
3502
3503         case PMC_OP_GETDRIVERSTATS:
3504         {
3505                 struct pmc_op_getdriverstats gms;
3506 #define CFETCH(a, b, field) a.field = counter_u64_fetch(b.field)
3507                 CFETCH(gms, pmc_stats, pm_intr_ignored);
3508                 CFETCH(gms, pmc_stats, pm_intr_processed);
3509                 CFETCH(gms, pmc_stats, pm_intr_bufferfull);
3510                 CFETCH(gms, pmc_stats, pm_syscalls);
3511                 CFETCH(gms, pmc_stats, pm_syscall_errors);
3512                 CFETCH(gms, pmc_stats, pm_buffer_requests);
3513                 CFETCH(gms, pmc_stats, pm_buffer_requests_failed);
3514                 CFETCH(gms, pmc_stats, pm_log_sweeps);
3515 #undef CFETCH
3516                 error = copyout(&gms, arg, sizeof(gms));
3517         }
3518         break;
3519
3520
3521         /*
3522          * Retrieve module version number
3523          */
3524
3525         case PMC_OP_GETMODULEVERSION:
3526         {
3527                 uint32_t cv, modv;
3528
3529                 /* retrieve the client's idea of the ABI version */
3530                 if ((error = copyin(arg, &cv, sizeof(uint32_t))) != 0)
3531                         break;
3532                 /* don't service clients newer than our driver */
3533                 modv = PMC_VERSION;
3534                 if ((cv & 0xFFFF0000) > (modv & 0xFFFF0000)) {
3535                         error = EPROGMISMATCH;
3536                         break;
3537                 }
3538                 error = copyout(&modv, arg, sizeof(int));
3539         }
3540         break;
3541
3542
3543         /*
3544          * Retrieve the state of all the PMCs on a given
3545          * CPU.
3546          */
3547
3548         case PMC_OP_GETPMCINFO:
3549         {
3550                 int ari;
3551                 struct pmc *pm;
3552                 size_t pmcinfo_size;
3553                 uint32_t cpu, n, npmc;
3554                 struct pmc_owner *po;
3555                 struct pmc_binding pb;
3556                 struct pmc_classdep *pcd;
3557                 struct pmc_info *p, *pmcinfo;
3558                 struct pmc_op_getpmcinfo *gpi;
3559
3560                 PMC_DOWNGRADE_SX();
3561
3562                 gpi = (struct pmc_op_getpmcinfo *) arg;
3563
3564                 if ((error = copyin(&gpi->pm_cpu, &cpu, sizeof(cpu))) != 0)
3565                         break;
3566
3567                 if (cpu >= pmc_cpu_max()) {
3568                         error = EINVAL;
3569                         break;
3570                 }
3571
3572                 if (!pmc_cpu_is_active(cpu)) {
3573                         error = ENXIO;
3574                         break;
3575                 }
3576
3577                 /* switch to CPU 'cpu' */
3578                 pmc_save_cpu_binding(&pb);
3579                 pmc_select_cpu(cpu);
3580
3581                 npmc = md->pmd_npmc;
3582
3583                 pmcinfo_size = npmc * sizeof(struct pmc_info);
3584                 pmcinfo = malloc(pmcinfo_size, M_PMC, M_WAITOK);
3585
3586                 p = pmcinfo;
3587
3588                 for (n = 0; n < md->pmd_npmc; n++, p++) {
3589
3590                         pcd = pmc_ri_to_classdep(md, n, &ari);
3591
3592                         KASSERT(pcd != NULL,
3593                             ("[pmc,%d] null pcd ri=%d", __LINE__, n));
3594
3595                         if ((error = pcd->pcd_describe(cpu, ari, p, &pm)) != 0)
3596                                 break;
3597
3598                         if (PMC_ROW_DISP_IS_STANDALONE(n))
3599                                 p->pm_rowdisp = PMC_DISP_STANDALONE;
3600                         else if (PMC_ROW_DISP_IS_THREAD(n))
3601                                 p->pm_rowdisp = PMC_DISP_THREAD;
3602                         else
3603                                 p->pm_rowdisp = PMC_DISP_FREE;
3604
3605                         p->pm_ownerpid = -1;
3606
3607                         if (pm == NULL) /* no PMC associated */
3608                                 continue;
3609
3610                         po = pm->pm_owner;
3611
3612                         KASSERT(po->po_owner != NULL,
3613                             ("[pmc,%d] pmc_owner had a null proc pointer",
3614                                 __LINE__));
3615
3616                         p->pm_ownerpid = po->po_owner->p_pid;
3617                         p->pm_mode     = PMC_TO_MODE(pm);
3618                         p->pm_event    = pm->pm_event;
3619                         p->pm_flags    = pm->pm_flags;
3620
3621                         if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)))
3622                                 p->pm_reloadcount =
3623                                     pm->pm_sc.pm_reloadcount;
3624                 }
3625
3626                 pmc_restore_cpu_binding(&pb);
3627
3628                 /* now copy out the PMC info collected */
3629                 if (error == 0)
3630                         error = copyout(pmcinfo, &gpi->pm_pmcs, pmcinfo_size);
3631
3632                 free(pmcinfo, M_PMC);
3633         }
3634         break;
3635
3636
3637         /*
3638          * Set the administrative state of a PMC.  I.e. whether
3639          * the PMC is to be used or not.
3640          */
3641
3642         case PMC_OP_PMCADMIN:
3643         {
3644                 int cpu, ri;
3645                 enum pmc_state request;
3646                 struct pmc_cpu *pc;
3647                 struct pmc_hw *phw;
3648                 struct pmc_op_pmcadmin pma;
3649                 struct pmc_binding pb;
3650
3651                 sx_assert(&pmc_sx, SX_XLOCKED);
3652
3653                 KASSERT(td == curthread,
3654                     ("[pmc,%d] td != curthread", __LINE__));
3655
3656                 error = priv_check(td, PRIV_PMC_MANAGE);
3657                 if (error)
3658                         break;
3659
3660                 if ((error = copyin(arg, &pma, sizeof(pma))) != 0)
3661                         break;
3662
3663                 cpu = pma.pm_cpu;
3664
3665                 if (cpu < 0 || cpu >= (int) pmc_cpu_max()) {
3666                         error = EINVAL;
3667                         break;
3668                 }
3669
3670                 if (!pmc_cpu_is_active(cpu)) {
3671                         error = ENXIO;
3672                         break;
3673                 }
3674
3675                 request = pma.pm_state;
3676
3677                 if (request != PMC_STATE_DISABLED &&
3678                     request != PMC_STATE_FREE) {
3679                         error = EINVAL;
3680                         break;
3681                 }
3682
3683                 ri = pma.pm_pmc; /* pmc id == row index */
3684                 if (ri < 0 || ri >= (int) md->pmd_npmc) {
3685                         error = EINVAL;
3686                         break;
3687                 }
3688
3689                 /*
3690                  * We can't disable a PMC with a row-index allocated
3691                  * for process virtual PMCs.
3692                  */
3693
3694                 if (PMC_ROW_DISP_IS_THREAD(ri) &&
3695                     request == PMC_STATE_DISABLED) {
3696                         error = EBUSY;
3697                         break;
3698                 }
3699
3700                 /*
3701                  * otherwise, this PMC on this CPU is either free or
3702                  * in system-wide mode.
3703                  */
3704
3705                 pmc_save_cpu_binding(&pb);
3706                 pmc_select_cpu(cpu);
3707
3708                 pc  = pmc_pcpu[cpu];
3709                 phw = pc->pc_hwpmcs[ri];
3710
3711                 /*
3712                  * XXX do we need some kind of 'forced' disable?
3713                  */
3714
3715                 if (phw->phw_pmc == NULL) {
3716                         if (request == PMC_STATE_DISABLED &&
3717                             (phw->phw_state & PMC_PHW_FLAG_IS_ENABLED)) {
3718                                 phw->phw_state &= ~PMC_PHW_FLAG_IS_ENABLED;
3719                                 PMC_MARK_ROW_STANDALONE(ri);
3720                         } else if (request == PMC_STATE_FREE &&
3721                             (phw->phw_state & PMC_PHW_FLAG_IS_ENABLED) == 0) {
3722                                 phw->phw_state |=  PMC_PHW_FLAG_IS_ENABLED;
3723                                 PMC_UNMARK_ROW_STANDALONE(ri);
3724                         }
3725                         /* other cases are a no-op */
3726                 } else
3727                         error = EBUSY;
3728
3729                 pmc_restore_cpu_binding(&pb);
3730         }
3731         break;
3732
3733
3734         /*
3735          * Allocate a PMC.
3736          */
3737
3738         case PMC_OP_PMCALLOCATE:
3739         {
3740                 int adjri, n;
3741                 u_int cpu;
3742                 uint32_t caps;
3743                 struct pmc *pmc;
3744                 enum pmc_mode mode;
3745                 struct pmc_hw *phw;
3746                 struct pmc_binding pb;
3747                 struct pmc_classdep *pcd;
3748                 struct pmc_op_pmcallocate pa;
3749
3750                 if ((error = copyin(arg, &pa, sizeof(pa))) != 0)
3751                         break;
3752
3753                 caps = pa.pm_caps;
3754                 mode = pa.pm_mode;
3755                 cpu  = pa.pm_cpu;
3756
3757                 if ((mode != PMC_MODE_SS  &&  mode != PMC_MODE_SC  &&
3758                      mode != PMC_MODE_TS  &&  mode != PMC_MODE_TC) ||
3759                     (cpu != (u_int) PMC_CPU_ANY && cpu >= pmc_cpu_max())) {
3760                         error = EINVAL;
3761                         break;
3762                 }
3763
3764                 /*
3765                  * Virtual PMCs should only ask for a default CPU.
3766                  * System mode PMCs need to specify a non-default CPU.
3767                  */
3768
3769                 if ((PMC_IS_VIRTUAL_MODE(mode) && cpu != (u_int) PMC_CPU_ANY) ||
3770                     (PMC_IS_SYSTEM_MODE(mode) && cpu == (u_int) PMC_CPU_ANY)) {
3771                         error = EINVAL;
3772                         break;
3773                 }
3774
3775                 /*
3776                  * Check that an inactive CPU is not being asked for.
3777                  */
3778
3779                 if (PMC_IS_SYSTEM_MODE(mode) && !pmc_cpu_is_active(cpu)) {
3780                         error = ENXIO;
3781                         break;
3782                 }
3783
3784                 /*
3785                  * Refuse an allocation for a system-wide PMC if this
3786                  * process has been jailed, or if this process lacks
3787                  * super-user credentials and the sysctl tunable
3788                  * 'security.bsd.unprivileged_syspmcs' is zero.
3789                  */
3790
3791                 if (PMC_IS_SYSTEM_MODE(mode)) {
3792                         if (jailed(curthread->td_ucred)) {
3793                                 error = EPERM;
3794                                 break;
3795                         }
3796                         if (!pmc_unprivileged_syspmcs) {
3797                                 error = priv_check(curthread,
3798                                     PRIV_PMC_SYSTEM);
3799                                 if (error)
3800                                         break;
3801                         }
3802                 }
3803
3804                 /*
3805                  * Look for valid values for 'pm_flags'
3806                  */
3807
3808                 if ((pa.pm_flags & ~(PMC_F_DESCENDANTS | PMC_F_LOG_PROCCSW |
3809                     PMC_F_LOG_PROCEXIT | PMC_F_CALLCHAIN)) != 0) {
3810                         error = EINVAL;
3811                         break;
3812                 }
3813
3814                 /* process logging options are not allowed for system PMCs */
3815                 if (PMC_IS_SYSTEM_MODE(mode) && (pa.pm_flags &
3816                     (PMC_F_LOG_PROCCSW | PMC_F_LOG_PROCEXIT))) {
3817                         error = EINVAL;
3818                         break;
3819                 }
3820
3821                 /*
3822                  * All sampling mode PMCs need to be able to interrupt the
3823                  * CPU.
3824                  */
3825                 if (PMC_IS_SAMPLING_MODE(mode))
3826                         caps |= PMC_CAP_INTERRUPT;
3827
3828                 /* A valid class specifier should have been passed in. */
3829                 pcd = pmc_class_to_classdep(pa.pm_class);
3830                 if (pcd == NULL) {
3831                         error = EINVAL;
3832                         break;
3833                 }
3834
3835                 /* The requested PMC capabilities should be feasible. */
3836                 if ((pcd->pcd_caps & caps) != caps) {
3837                         error = EOPNOTSUPP;
3838                         break;
3839                 }
3840
3841                 PMCDBG4(PMC,ALL,2, "event=%d caps=0x%x mode=%d cpu=%d",
3842                     pa.pm_ev, caps, mode, cpu);
3843
3844                 pmc = pmc_allocate_pmc_descriptor();
3845                 pmc->pm_id    = PMC_ID_MAKE_ID(cpu,pa.pm_mode,pa.pm_class,
3846                     PMC_ID_INVALID);
3847                 pmc->pm_event = pa.pm_ev;
3848                 pmc->pm_state = PMC_STATE_FREE;
3849                 pmc->pm_caps  = caps;
3850                 pmc->pm_flags = pa.pm_flags;
3851
3852                 /* switch thread to CPU 'cpu' */
3853                 pmc_save_cpu_binding(&pb);
3854
3855 #define PMC_IS_SHAREABLE_PMC(cpu, n)                            \
3856         (pmc_pcpu[(cpu)]->pc_hwpmcs[(n)]->phw_state &           \
3857          PMC_PHW_FLAG_IS_SHAREABLE)
3858 #define PMC_IS_UNALLOCATED(cpu, n)                              \
3859         (pmc_pcpu[(cpu)]->pc_hwpmcs[(n)]->phw_pmc == NULL)
3860
3861                 if (PMC_IS_SYSTEM_MODE(mode)) {
3862                         pmc_select_cpu(cpu);
3863                         for (n = pcd->pcd_ri; n < (int) md->pmd_npmc; n++) {
3864                                 pcd = pmc_ri_to_classdep(md, n, &adjri);
3865                                 if (pmc_can_allocate_row(n, mode) == 0 &&
3866                                     pmc_can_allocate_rowindex(
3867                                             curthread->td_proc, n, cpu) == 0 &&
3868                                     (PMC_IS_UNALLOCATED(cpu, n) ||
3869                                      PMC_IS_SHAREABLE_PMC(cpu, n)) &&
3870                                     pcd->pcd_allocate_pmc(cpu, adjri, pmc,
3871                                         &pa) == 0)
3872                                         break;
3873                         }
3874                 } else {
3875                         /* Process virtual mode */
3876                         for (n = pcd->pcd_ri; n < (int) md->pmd_npmc; n++) {
3877                                 pcd = pmc_ri_to_classdep(md, n, &adjri);
3878                                 if (pmc_can_allocate_row(n, mode) == 0 &&
3879                                     pmc_can_allocate_rowindex(
3880                                             curthread->td_proc, n,
3881                                             PMC_CPU_ANY) == 0 &&
3882                                     pcd->pcd_allocate_pmc(curthread->td_oncpu,
3883                                         adjri, pmc, &pa) == 0)
3884                                         break;
3885                         }
3886                 }
3887
3888 #undef  PMC_IS_UNALLOCATED
3889 #undef  PMC_IS_SHAREABLE_PMC
3890
3891                 pmc_restore_cpu_binding(&pb);
3892
3893                 if (n == (int) md->pmd_npmc) {
3894                         pmc_destroy_pmc_descriptor(pmc);
3895                         pmc = NULL;
3896                         error = EINVAL;
3897                         break;
3898                 }
3899
3900                 /* Fill in the correct value in the ID field */
3901                 pmc->pm_id = PMC_ID_MAKE_ID(cpu,mode,pa.pm_class,n);
3902
3903                 PMCDBG5(PMC,ALL,2, "ev=%d class=%d mode=%d n=%d -> pmcid=%x",
3904                     pmc->pm_event, pa.pm_class, mode, n, pmc->pm_id);
3905
3906                 /* Process mode PMCs with logging enabled need log files */
3907                 if (pmc->pm_flags & (PMC_F_LOG_PROCEXIT | PMC_F_LOG_PROCCSW))
3908                         pmc->pm_flags |= PMC_F_NEEDS_LOGFILE;
3909
3910                 /* All system mode sampling PMCs require a log file */
3911                 if (PMC_IS_SAMPLING_MODE(mode) && PMC_IS_SYSTEM_MODE(mode))
3912                         pmc->pm_flags |= PMC_F_NEEDS_LOGFILE;
3913
3914                 /*
3915                  * Configure global pmc's immediately
3916                  */
3917
3918                 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pmc))) {
3919
3920                         pmc_save_cpu_binding(&pb);
3921                         pmc_select_cpu(cpu);
3922
3923                         phw = pmc_pcpu[cpu]->pc_hwpmcs[n];
3924                         pcd = pmc_ri_to_classdep(md, n, &adjri);
3925
3926                         if ((phw->phw_state & PMC_PHW_FLAG_IS_ENABLED) == 0 ||
3927                             (error = pcd->pcd_config_pmc(cpu, adjri, pmc)) != 0) {
3928                                 (void) pcd->pcd_release_pmc(cpu, adjri, pmc);
3929                                 pmc_destroy_pmc_descriptor(pmc);
3930                                 pmc = NULL;
3931                                 pmc_restore_cpu_binding(&pb);
3932                                 error = EPERM;
3933                                 break;
3934                         }
3935
3936                         pmc_restore_cpu_binding(&pb);
3937                 }
3938
3939                 pmc->pm_state    = PMC_STATE_ALLOCATED;
3940                 pmc->pm_class   = pa.pm_class;
3941
3942                 /*
3943                  * mark row disposition
3944                  */
3945
3946                 if (PMC_IS_SYSTEM_MODE(mode))
3947                         PMC_MARK_ROW_STANDALONE(n);
3948                 else
3949                         PMC_MARK_ROW_THREAD(n);
3950
3951                 /*
3952                  * Register this PMC with the current thread as its owner.
3953                  */
3954
3955                 if ((error =
3956                     pmc_register_owner(curthread->td_proc, pmc)) != 0) {
3957                         pmc_release_pmc_descriptor(pmc);
3958                         pmc_destroy_pmc_descriptor(pmc);
3959                         pmc = NULL;
3960                         break;
3961                 }
3962
3963                 /*
3964                  * Return the allocated index.
3965                  */
3966
3967                 pa.pm_pmcid = pmc->pm_id;
3968
3969                 error = copyout(&pa, arg, sizeof(pa));
3970         }
3971         break;
3972
3973
3974         /*
3975          * Attach a PMC to a process.
3976          */
3977
3978         case PMC_OP_PMCATTACH:
3979         {
3980                 struct pmc *pm;
3981                 struct proc *p;
3982                 struct pmc_op_pmcattach a;
3983
3984                 sx_assert(&pmc_sx, SX_XLOCKED);
3985
3986                 if ((error = copyin(arg, &a, sizeof(a))) != 0)
3987                         break;
3988
3989                 if (a.pm_pid < 0) {
3990                         error = EINVAL;
3991                         break;
3992                 } else if (a.pm_pid == 0)
3993                         a.pm_pid = td->td_proc->p_pid;
3994
3995                 if ((error = pmc_find_pmc(a.pm_pmc, &pm)) != 0)
3996                         break;
3997
3998                 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pm))) {
3999                         error = EINVAL;
4000                         break;
4001                 }
4002
4003                 /* PMCs may be (re)attached only when allocated or stopped */
4004                 if (pm->pm_state == PMC_STATE_RUNNING) {
4005                         error = EBUSY;
4006                         break;
4007                 } else if (pm->pm_state != PMC_STATE_ALLOCATED &&
4008                     pm->pm_state != PMC_STATE_STOPPED) {
4009                         error = EINVAL;
4010                         break;
4011                 }
4012
4013                 /* lookup pid */
4014                 if ((p = pfind(a.pm_pid)) == NULL) {
4015                         error = ESRCH;
4016                         break;
4017                 }
4018
4019                 /*
4020                  * Ignore processes that are working on exiting.
4021                  */
4022                 if (p->p_flag & P_WEXIT) {
4023                         error = ESRCH;
4024                         PROC_UNLOCK(p); /* pfind() returns a locked process */
4025                         break;
4026                 }
4027
4028                 /*
4029                  * we are allowed to attach a PMC to a process if
4030                  * we can debug it.
4031                  */
4032                 error = p_candebug(curthread, p);
4033
4034                 PROC_UNLOCK(p);
4035
4036                 if (error == 0)
4037                         error = pmc_attach_process(p, pm);
4038         }
4039         break;
4040
4041
4042         /*
4043          * Detach an attached PMC from a process.
4044          */
4045
4046         case PMC_OP_PMCDETACH:
4047         {
4048                 struct pmc *pm;
4049                 struct proc *p;
4050                 struct pmc_op_pmcattach a;
4051
4052                 if ((error = copyin(arg, &a, sizeof(a))) != 0)
4053                         break;
4054
4055                 if (a.pm_pid < 0) {
4056                         error = EINVAL;
4057                         break;
4058                 } else if (a.pm_pid == 0)
4059                         a.pm_pid = td->td_proc->p_pid;
4060
4061                 if ((error = pmc_find_pmc(a.pm_pmc, &pm)) != 0)
4062                         break;
4063
4064                 if ((p = pfind(a.pm_pid)) == NULL) {
4065                         error = ESRCH;
4066                         break;
4067                 }
4068
4069                 /*
4070                  * Treat processes that are in the process of exiting
4071                  * as if they were not present.
4072                  */
4073
4074                 if (p->p_flag & P_WEXIT)
4075                         error = ESRCH;
4076
4077                 PROC_UNLOCK(p); /* pfind() returns a locked process */
4078
4079                 if (error == 0)
4080                         error = pmc_detach_process(p, pm);
4081         }
4082         break;
4083
4084
4085         /*
4086          * Retrieve the MSR number associated with the counter
4087          * 'pmc_id'.  This allows processes to directly use RDPMC
4088          * instructions to read their PMCs, without the overhead of a
4089          * system call.
4090          */
4091
4092         case PMC_OP_PMCGETMSR:
4093         {
4094                 int adjri, ri;
4095                 struct pmc *pm;
4096                 struct pmc_target *pt;
4097                 struct pmc_op_getmsr gm;
4098                 struct pmc_classdep *pcd;
4099
4100                 PMC_DOWNGRADE_SX();
4101
4102                 if ((error = copyin(arg, &gm, sizeof(gm))) != 0)
4103                         break;
4104
4105                 if ((error = pmc_find_pmc(gm.pm_pmcid, &pm)) != 0)
4106                         break;
4107
4108                 /*
4109                  * The allocated PMC has to be a process virtual PMC,
4110                  * i.e., of type MODE_T[CS].  Global PMCs can only be
4111                  * read using the PMCREAD operation since they may be
4112                  * allocated on a different CPU than the one we could
4113                  * be running on at the time of the RDPMC instruction.
4114                  *
4115                  * The GETMSR operation is not allowed for PMCs that
4116                  * are inherited across processes.
4117                  */
4118
4119                 if (!PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)) ||
4120                     (pm->pm_flags & PMC_F_DESCENDANTS)) {
4121                         error = EINVAL;
4122                         break;
4123                 }
4124
4125                 /*
4126                  * It only makes sense to use a RDPMC (or its
4127                  * equivalent instruction on non-x86 architectures) on
4128                  * a process that has allocated and attached a PMC to
4129                  * itself.  Conversely the PMC is only allowed to have
4130                  * one process attached to it -- its owner.
4131                  */
4132
4133                 if ((pt = LIST_FIRST(&pm->pm_targets)) == NULL ||
4134                     LIST_NEXT(pt, pt_next) != NULL ||
4135                     pt->pt_process->pp_proc != pm->pm_owner->po_owner) {
4136                         error = EINVAL;
4137                         break;
4138                 }
4139
4140                 ri = PMC_TO_ROWINDEX(pm);
4141                 pcd = pmc_ri_to_classdep(md, ri, &adjri);
4142
4143                 /* PMC class has no 'GETMSR' support */
4144                 if (pcd->pcd_get_msr == NULL) {
4145                         error = ENOSYS;
4146                         break;
4147                 }
4148
4149                 if ((error = (*pcd->pcd_get_msr)(adjri, &gm.pm_msr)) < 0)
4150                         break;
4151
4152                 if ((error = copyout(&gm, arg, sizeof(gm))) < 0)
4153                         break;
4154
4155                 /*
4156                  * Mark our process as using MSRs.  Update machine
4157                  * state using a forced context switch.
4158                  */
4159
4160                 pt->pt_process->pp_flags |= PMC_PP_ENABLE_MSR_ACCESS;
4161                 pmc_force_context_switch();
4162
4163         }
4164         break;
4165
4166         /*
4167          * Release an allocated PMC
4168          */
4169
4170         case PMC_OP_PMCRELEASE:
4171         {
4172                 pmc_id_t pmcid;
4173                 struct pmc *pm;
4174                 struct pmc_owner *po;
4175                 struct pmc_op_simple sp;
4176
4177                 /*
4178                  * Find PMC pointer for the named PMC.
4179                  *
4180                  * Use pmc_release_pmc_descriptor() to switch off the
4181                  * PMC, remove all its target threads, and remove the
4182                  * PMC from its owner's list.
4183                  *
4184                  * Remove the owner record if this is the last PMC
4185                  * owned.
4186                  *
4187                  * Free up space.
4188                  */
4189
4190                 if ((error = copyin(arg, &sp, sizeof(sp))) != 0)
4191                         break;
4192
4193                 pmcid = sp.pm_pmcid;
4194
4195                 if ((error = pmc_find_pmc(pmcid, &pm)) != 0)
4196                         break;
4197
4198                 po = pm->pm_owner;
4199                 pmc_release_pmc_descriptor(pm);
4200                 pmc_maybe_remove_owner(po);
4201                 pmc_destroy_pmc_descriptor(pm);
4202         }
4203         break;
4204
4205
4206         /*
4207          * Read and/or write a PMC.
4208          */
4209
4210         case PMC_OP_PMCRW:
4211         {
4212                 int adjri;
4213                 struct pmc *pm;
4214                 uint32_t cpu, ri;
4215                 pmc_value_t oldvalue;
4216                 struct pmc_binding pb;
4217                 struct pmc_op_pmcrw prw;
4218                 struct pmc_classdep *pcd;
4219                 struct pmc_op_pmcrw *pprw;
4220
4221                 PMC_DOWNGRADE_SX();
4222
4223                 if ((error = copyin(arg, &prw, sizeof(prw))) != 0)
4224                         break;
4225
4226                 ri = 0;
4227                 PMCDBG2(PMC,OPS,1, "rw id=%d flags=0x%x", prw.pm_pmcid,
4228                     prw.pm_flags);
4229
4230                 /* must have at least one flag set */
4231                 if ((prw.pm_flags & (PMC_F_OLDVALUE|PMC_F_NEWVALUE)) == 0) {
4232                         error = EINVAL;
4233                         break;
4234                 }
4235
4236                 /* locate pmc descriptor */
4237                 if ((error = pmc_find_pmc(prw.pm_pmcid, &pm)) != 0)
4238                         break;
4239
4240                 /* Can't read a PMC that hasn't been started. */
4241                 if (pm->pm_state != PMC_STATE_ALLOCATED &&
4242                     pm->pm_state != PMC_STATE_STOPPED &&
4243                     pm->pm_state != PMC_STATE_RUNNING) {
4244                         error = EINVAL;
4245                         break;
4246                 }
4247
4248                 /* writing a new value is allowed only for 'STOPPED' pmcs */
4249                 if (pm->pm_state == PMC_STATE_RUNNING &&
4250                     (prw.pm_flags & PMC_F_NEWVALUE)) {
4251                         error = EBUSY;
4252                         break;
4253                 }
4254
4255                 if (PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) {
4256
4257                         /*
4258                          * If this PMC is attached to its owner (i.e.,
4259                          * the process requesting this operation) and
4260                          * is running, then attempt to get an
4261                          * upto-date reading from hardware for a READ.
4262                          * Writes are only allowed when the PMC is
4263                          * stopped, so only update the saved value
4264                          * field.
4265                          *
4266                          * If the PMC is not running, or is not
4267                          * attached to its owner, read/write to the
4268                          * savedvalue field.
4269                          */
4270
4271                         ri = PMC_TO_ROWINDEX(pm);
4272                         pcd = pmc_ri_to_classdep(md, ri, &adjri);
4273
4274                         mtx_pool_lock_spin(pmc_mtxpool, pm);
4275                         cpu = curthread->td_oncpu;
4276
4277                         if (prw.pm_flags & PMC_F_OLDVALUE) {
4278                                 if ((pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) &&
4279                                     (pm->pm_state == PMC_STATE_RUNNING))
4280                                         error = (*pcd->pcd_read_pmc)(cpu, adjri,
4281                                             &oldvalue);
4282                                 else
4283                                         oldvalue = pm->pm_gv.pm_savedvalue;
4284                         }
4285                         if (prw.pm_flags & PMC_F_NEWVALUE)
4286                                 pm->pm_gv.pm_savedvalue = prw.pm_value;
4287
4288                         mtx_pool_unlock_spin(pmc_mtxpool, pm);
4289
4290                 } else { /* System mode PMCs */
4291                         cpu = PMC_TO_CPU(pm);
4292                         ri  = PMC_TO_ROWINDEX(pm);
4293                         pcd = pmc_ri_to_classdep(md, ri, &adjri);
4294
4295                         if (!pmc_cpu_is_active(cpu)) {
4296                                 error = ENXIO;
4297                                 break;
4298                         }
4299
4300                         /* move this thread to CPU 'cpu' */
4301                         pmc_save_cpu_binding(&pb);
4302                         pmc_select_cpu(cpu);
4303
4304                         critical_enter();
4305                         /* save old value */
4306                         if (prw.pm_flags & PMC_F_OLDVALUE)
4307                                 if ((error = (*pcd->pcd_read_pmc)(cpu, adjri,
4308                                          &oldvalue)))
4309                                         goto error;
4310                         /* write out new value */
4311                         if (prw.pm_flags & PMC_F_NEWVALUE)
4312                                 error = (*pcd->pcd_write_pmc)(cpu, adjri,
4313                                     prw.pm_value);
4314                 error:
4315                         critical_exit();
4316                         pmc_restore_cpu_binding(&pb);
4317                         if (error)
4318                                 break;
4319                 }
4320
4321                 pprw = (struct pmc_op_pmcrw *) arg;
4322
4323 #ifdef  HWPMC_DEBUG
4324                 if (prw.pm_flags & PMC_F_NEWVALUE)
4325                         PMCDBG3(PMC,OPS,2, "rw id=%d new %jx -> old %jx",
4326                             ri, prw.pm_value, oldvalue);
4327                 else if (prw.pm_flags & PMC_F_OLDVALUE)
4328                         PMCDBG2(PMC,OPS,2, "rw id=%d -> old %jx", ri, oldvalue);
4329 #endif
4330
4331                 /* return old value if requested */
4332                 if (prw.pm_flags & PMC_F_OLDVALUE)
4333                         if ((error = copyout(&oldvalue, &pprw->pm_value,
4334                                  sizeof(prw.pm_value))))
4335                                 break;
4336
4337         }
4338         break;
4339
4340
4341         /*
4342          * Set the sampling rate for a sampling mode PMC and the
4343          * initial count for a counting mode PMC.
4344          */
4345
4346         case PMC_OP_PMCSETCOUNT:
4347         {
4348                 struct pmc *pm;
4349                 struct pmc_op_pmcsetcount sc;
4350
4351                 PMC_DOWNGRADE_SX();
4352
4353                 if ((error = copyin(arg, &sc, sizeof(sc))) != 0)
4354                         break;
4355
4356                 if ((error = pmc_find_pmc(sc.pm_pmcid, &pm)) != 0)
4357                         break;
4358
4359                 if (pm->pm_state == PMC_STATE_RUNNING) {
4360                         error = EBUSY;
4361                         break;
4362                 }
4363
4364                 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)))
4365                         pm->pm_sc.pm_reloadcount = sc.pm_count;
4366                 else
4367                         pm->pm_sc.pm_initial = sc.pm_count;
4368         }
4369         break;
4370
4371
4372         /*
4373          * Start a PMC.
4374          */
4375
4376         case PMC_OP_PMCSTART:
4377         {
4378                 pmc_id_t pmcid;
4379                 struct pmc *pm;
4380                 struct pmc_op_simple sp;
4381
4382                 sx_assert(&pmc_sx, SX_XLOCKED);
4383
4384                 if ((error = copyin(arg, &sp, sizeof(sp))) != 0)
4385                         break;
4386
4387                 pmcid = sp.pm_pmcid;
4388
4389                 if ((error = pmc_find_pmc(pmcid, &pm)) != 0)
4390                         break;
4391
4392                 KASSERT(pmcid == pm->pm_id,
4393                     ("[pmc,%d] pmcid %x != id %x", __LINE__,
4394                         pm->pm_id, pmcid));
4395
4396                 if (pm->pm_state == PMC_STATE_RUNNING) /* already running */
4397                         break;
4398                 else if (pm->pm_state != PMC_STATE_STOPPED &&
4399                     pm->pm_state != PMC_STATE_ALLOCATED) {
4400                         error = EINVAL;
4401                         break;
4402                 }
4403
4404                 error = pmc_start(pm);
4405         }
4406         break;
4407
4408
4409         /*
4410          * Stop a PMC.
4411          */
4412
4413         case PMC_OP_PMCSTOP:
4414         {
4415                 pmc_id_t pmcid;
4416                 struct pmc *pm;
4417                 struct pmc_op_simple sp;
4418
4419                 PMC_DOWNGRADE_SX();
4420
4421                 if ((error = copyin(arg, &sp, sizeof(sp))) != 0)
4422                         break;
4423
4424                 pmcid = sp.pm_pmcid;
4425
4426                 /*
4427                  * Mark the PMC as inactive and invoke the MD stop
4428                  * routines if needed.
4429                  */
4430
4431                 if ((error = pmc_find_pmc(pmcid, &pm)) != 0)
4432                         break;
4433
4434                 KASSERT(pmcid == pm->pm_id,
4435                     ("[pmc,%d] pmc id %x != pmcid %x", __LINE__,
4436                         pm->pm_id, pmcid));
4437
4438                 if (pm->pm_state == PMC_STATE_STOPPED) /* already stopped */
4439                         break;
4440                 else if (pm->pm_state != PMC_STATE_RUNNING) {
4441                         error = EINVAL;
4442                         break;
4443                 }
4444
4445                 error = pmc_stop(pm);
4446         }
4447         break;
4448
4449
4450         /*
4451          * Write a user supplied value to the log file.
4452          */
4453
4454         case PMC_OP_WRITELOG:
4455         {
4456                 struct pmc_op_writelog wl;
4457                 struct pmc_owner *po;
4458
4459                 PMC_DOWNGRADE_SX();
4460
4461                 if ((error = copyin(arg, &wl, sizeof(wl))) != 0)
4462                         break;
4463
4464                 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) {
4465                         error = EINVAL;
4466                         break;
4467                 }
4468
4469                 if ((po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) {
4470                         error = EINVAL;
4471                         break;
4472                 }
4473
4474                 error = pmclog_process_userlog(po, &wl);
4475         }
4476         break;
4477
4478
4479         default:
4480                 error = EINVAL;
4481                 break;
4482         }
4483
4484         if (is_sx_downgraded)
4485                 sx_sunlock(&pmc_sx);
4486         else
4487                 sx_xunlock(&pmc_sx);
4488 done_syscall:
4489         if (error)
4490                 counter_u64_add(pmc_stats.pm_syscall_errors, 1);
4491
4492         return (error);
4493 }
4494
4495 /*
4496  * Helper functions
4497  */
4498
4499
4500 /*
4501  * Mark the thread as needing callchain capture and post an AST.  The
4502  * actual callchain capture will be done in a context where it is safe
4503  * to take page faults.
4504  */
4505
4506 static void
4507 pmc_post_callchain_callback(void)
4508 {
4509         struct thread *td;
4510
4511         td = curthread;
4512
4513         /*
4514          * If there is multiple PMCs for the same interrupt ignore new post
4515          */
4516         if (td->td_pflags & TDP_CALLCHAIN)
4517                 return;
4518
4519         /*
4520          * Mark this thread as needing callchain capture.
4521          * `td->td_pflags' will be safe to touch because this thread
4522          * was in user space when it was interrupted.
4523          */
4524         td->td_pflags |= TDP_CALLCHAIN;
4525
4526         /*
4527          * Don't let this thread migrate between CPUs until callchain
4528          * capture completes.
4529          */
4530         sched_pin();
4531
4532         return;
4533 }
4534
4535 /*
4536  * Interrupt processing.
4537  *
4538  * Find a free slot in the per-cpu array of samples and capture the
4539  * current callchain there.  If a sample was successfully added, a bit
4540  * is set in mask 'pmc_cpumask' denoting that the DO_SAMPLES hook
4541  * needs to be invoked from the clock handler.
4542  *
4543  * This function is meant to be called from an NMI handler.  It cannot
4544  * use any of the locking primitives supplied by the OS.
4545  */
4546
4547 int
4548 pmc_process_interrupt(int cpu, int ring, struct pmc *pm, struct trapframe *tf,
4549     int inuserspace)
4550 {
4551         int error, callchaindepth;
4552         struct thread *td;
4553         struct pmc_sample *ps;
4554         struct pmc_samplebuffer *psb;
4555
4556         error = 0;
4557
4558         /*
4559          * Allocate space for a sample buffer.
4560          */
4561         psb = pmc_pcpu[cpu]->pc_sb[ring];
4562
4563         ps = psb->ps_write;
4564         if (ps->ps_nsamples) {  /* in use, reader hasn't caught up */
4565                 pm->pm_pcpu_state[cpu].pps_stalled = 1;
4566                 counter_u64_add(pmc_stats.pm_intr_bufferfull, 1);
4567                 PMCDBG6(SAM,INT,1,"(spc) cpu=%d pm=%p tf=%p um=%d wr=%d rd=%d",
4568                     cpu, pm, (void *) tf, inuserspace,
4569                     (int) (psb->ps_write - psb->ps_samples),
4570                     (int) (psb->ps_read - psb->ps_samples));
4571                 callchaindepth = 1;
4572                 error = ENOMEM;
4573                 goto done;
4574         }
4575
4576
4577         /* Fill in entry. */
4578         PMCDBG6(SAM,INT,1,"cpu=%d pm=%p tf=%p um=%d wr=%d rd=%d", cpu, pm,
4579             (void *) tf, inuserspace,
4580             (int) (psb->ps_write - psb->ps_samples),
4581             (int) (psb->ps_read - psb->ps_samples));
4582
4583         KASSERT(counter_u64_fetch(pm->pm_runcount) >= 0,
4584             ("[pmc,%d] pm=%p runcount %ld", __LINE__, (void *) pm,
4585                  (unsigned long)counter_u64_fetch(pm->pm_runcount)));
4586
4587         counter_u64_add(pm->pm_runcount, 1);    /* hold onto PMC */
4588
4589         ps->ps_pmc = pm;
4590         ps->ps_pid = -1;
4591         ps->ps_tid = -1;
4592         if ((td = curthread) != NULL) {
4593                 ps->ps_tid = td->td_tid;
4594                 if (td->td_proc)
4595                         ps->ps_pid = td->td_proc->p_pid;
4596         }
4597         ps->ps_cpu = cpu;
4598         ps->ps_td = td;
4599         ps->ps_flags = inuserspace ? PMC_CC_F_USERSPACE : 0;
4600
4601         callchaindepth = (pm->pm_flags & PMC_F_CALLCHAIN) ?
4602             pmc_callchaindepth : 1;
4603
4604         if (callchaindepth == 1)
4605                 ps->ps_pc[0] = PMC_TRAPFRAME_TO_PC(tf);
4606         else {
4607                 /*
4608                  * Kernel stack traversals can be done immediately,
4609                  * while we defer to an AST for user space traversals.
4610                  */
4611                 if (!inuserspace) {
4612                         callchaindepth =
4613                             pmc_save_kernel_callchain(ps->ps_pc,
4614                                 callchaindepth, tf);
4615                 } else {
4616                         pmc_post_callchain_callback();
4617                         callchaindepth = PMC_SAMPLE_INUSE;
4618                 }
4619         }
4620
4621         ps->ps_nsamples = callchaindepth;       /* mark entry as in use */
4622
4623         /* increment write pointer, modulo ring buffer size */
4624         ps++;
4625         if (ps == psb->ps_fence)
4626                 psb->ps_write = psb->ps_samples;
4627         else
4628                 psb->ps_write = ps;
4629
4630  done:
4631         /* mark CPU as needing processing */
4632         if (callchaindepth != PMC_SAMPLE_INUSE)
4633                 DPCPU_SET(pmc_sampled, 1);
4634
4635         return (error);
4636 }
4637
4638 /*
4639  * Capture a user call chain.  This function will be called from ast()
4640  * before control returns to userland and before the process gets
4641  * rescheduled.
4642  */
4643
4644 static void
4645 pmc_capture_user_callchain(int cpu, int ring, struct trapframe *tf)
4646 {
4647         struct pmc *pm;
4648         struct thread *td;
4649         struct pmc_sample *ps, *ps_end;
4650         struct pmc_samplebuffer *psb;
4651 #ifdef  INVARIANTS
4652         int ncallchains;
4653         int nfree;
4654 #endif
4655
4656         psb = pmc_pcpu[cpu]->pc_sb[ring];
4657         td = curthread;
4658
4659         KASSERT(td->td_pflags & TDP_CALLCHAIN,
4660             ("[pmc,%d] Retrieving callchain for thread that doesn't want it",
4661                 __LINE__));
4662
4663 #ifdef  INVARIANTS
4664         ncallchains = 0;
4665         nfree = 0;
4666 #endif
4667
4668         /*
4669          * Iterate through all deferred callchain requests.
4670          * Walk from the current read pointer to the current
4671          * write pointer.
4672          */
4673
4674         ps = psb->ps_read;
4675         ps_end = psb->ps_write;
4676         do {
4677 #ifdef  INVARIANTS
4678                 if ((ps->ps_pmc == NULL) ||
4679                     (ps->ps_pmc->pm_state != PMC_STATE_RUNNING))
4680                         nfree++;
4681 #endif
4682                 if (ps->ps_nsamples != PMC_SAMPLE_INUSE)
4683                         goto next;
4684                 if (ps->ps_td != td)
4685                         goto next;
4686
4687                 KASSERT(ps->ps_cpu == cpu,
4688                     ("[pmc,%d] cpu mismatch ps_cpu=%d pcpu=%d", __LINE__,
4689                         ps->ps_cpu, PCPU_GET(cpuid)));
4690
4691                 pm = ps->ps_pmc;
4692
4693                 KASSERT(pm->pm_flags & PMC_F_CALLCHAIN,
4694                     ("[pmc,%d] Retrieving callchain for PMC that doesn't "
4695                         "want it", __LINE__));
4696
4697                 KASSERT(counter_u64_fetch(pm->pm_runcount) > 0,
4698                     ("[pmc,%d] runcount %ld", __LINE__, (unsigned long)counter_u64_fetch(pm->pm_runcount)));
4699
4700                 /*
4701                  * Retrieve the callchain and mark the sample buffer
4702                  * as 'processable' by the timer tick sweep code.
4703                  */
4704                 ps->ps_nsamples = pmc_save_user_callchain(ps->ps_pc,
4705                     pmc_callchaindepth, tf);
4706
4707 #ifdef  INVARIANTS
4708                 ncallchains++;
4709 #endif
4710
4711 next:
4712                 /* increment the pointer, modulo sample ring size */
4713                 if (++ps == psb->ps_fence)
4714                         ps = psb->ps_samples;
4715         } while (ps != ps_end);
4716
4717 #ifdef  INVARIANTS
4718         KASSERT(ncallchains > 0 || nfree > 0,
4719             ("[pmc,%d] cpu %d didn't find a sample to collect", __LINE__,
4720                 cpu));
4721 #endif
4722
4723         KASSERT(td->td_pinned == 1,
4724             ("[pmc,%d] invalid td_pinned value", __LINE__));
4725         sched_unpin();  /* Can migrate safely now. */
4726
4727         /* mark CPU as needing processing */
4728         DPCPU_SET(pmc_sampled, 1);
4729 }
4730
4731 /*
4732  * Process saved PC samples.
4733  */
4734
4735 static void
4736 pmc_process_samples(int cpu, int ring)
4737 {
4738         struct pmc *pm;
4739         int adjri, n;
4740         struct thread *td;
4741         struct pmc_owner *po;
4742         struct pmc_sample *ps;
4743         struct pmc_classdep *pcd;
4744         struct pmc_samplebuffer *psb;
4745
4746         KASSERT(PCPU_GET(cpuid) == cpu,
4747             ("[pmc,%d] not on the correct CPU pcpu=%d cpu=%d", __LINE__,
4748                 PCPU_GET(cpuid), cpu));
4749
4750         psb = pmc_pcpu[cpu]->pc_sb[ring];
4751
4752         for (n = 0; n < pmc_nsamples; n++) { /* bound on #iterations */
4753
4754                 ps = psb->ps_read;
4755                 if (ps->ps_nsamples == PMC_SAMPLE_FREE)
4756                         break;
4757
4758                 pm = ps->ps_pmc;
4759
4760                 KASSERT(counter_u64_fetch(pm->pm_runcount) > 0,
4761                     ("[pmc,%d] pm=%p runcount %ld", __LINE__, (void *) pm,
4762                          (unsigned long)counter_u64_fetch(pm->pm_runcount)));
4763
4764                 po = pm->pm_owner;
4765
4766                 KASSERT(PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)),
4767                     ("[pmc,%d] pmc=%p non-sampling mode=%d", __LINE__,
4768                         pm, PMC_TO_MODE(pm)));
4769
4770                 /* Ignore PMCs that have been switched off */
4771                 if (pm->pm_state != PMC_STATE_RUNNING)
4772                         goto entrydone;
4773
4774                 /* If there is a pending AST wait for completion */
4775                 if (ps->ps_nsamples == PMC_SAMPLE_INUSE) {
4776                         /* Need a rescan at a later time. */
4777                         DPCPU_SET(pmc_sampled, 1);
4778                         break;
4779                 }
4780
4781                 PMCDBG6(SAM,OPS,1,"cpu=%d pm=%p n=%d fl=%x wr=%d rd=%d", cpu,
4782                     pm, ps->ps_nsamples, ps->ps_flags,
4783                     (int) (psb->ps_write - psb->ps_samples),
4784                     (int) (psb->ps_read - psb->ps_samples));
4785
4786                 /*
4787                  * If this is a process-mode PMC that is attached to
4788                  * its owner, and if the PC is in user mode, update
4789                  * profiling statistics like timer-based profiling
4790                  * would have done.
4791                  */
4792                 if (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) {
4793                         if (ps->ps_flags & PMC_CC_F_USERSPACE) {
4794                                 td = FIRST_THREAD_IN_PROC(po->po_owner);
4795                                 addupc_intr(td, ps->ps_pc[0], 1);
4796                         }
4797                         goto entrydone;
4798                 }
4799
4800                 /*
4801                  * Otherwise, this is either a sampling mode PMC that
4802                  * is attached to a different process than its owner,
4803                  * or a system-wide sampling PMC.  Dispatch a log
4804                  * entry to the PMC's owner process.
4805                  */
4806                 pmclog_process_callchain(pm, ps);
4807
4808         entrydone:
4809                 ps->ps_nsamples = 0; /* mark entry as free */
4810                 counter_u64_add(pm->pm_runcount, -1);
4811
4812                 /* increment read pointer, modulo sample size */
4813                 if (++ps == psb->ps_fence)
4814                         psb->ps_read = psb->ps_samples;
4815                 else
4816                         psb->ps_read = ps;
4817         }
4818
4819         counter_u64_add(pmc_stats.pm_log_sweeps, 1);
4820
4821         /* Do not re-enable stalled PMCs if we failed to process any samples */
4822         if (n == 0)
4823                 return;
4824
4825         /*
4826          * Restart any stalled sampling PMCs on this CPU.
4827          *
4828          * If the NMI handler sets the pm_stalled field of a PMC after
4829          * the check below, we'll end up processing the stalled PMC at
4830          * the next hardclock tick.
4831          */
4832         for (n = 0; n < md->pmd_npmc; n++) {
4833                 pcd = pmc_ri_to_classdep(md, n, &adjri);
4834                 KASSERT(pcd != NULL,
4835                     ("[pmc,%d] null pcd ri=%d", __LINE__, n));
4836                 (void) (*pcd->pcd_get_config)(cpu,adjri,&pm);
4837
4838                 if (pm == NULL ||                        /* !cfg'ed */
4839                     pm->pm_state != PMC_STATE_RUNNING || /* !active */
4840                     !PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)) || /* !sampling */
4841                         !pm->pm_pcpu_state[cpu].pps_cpustate  || /* !desired */
4842                     !pm->pm_pcpu_state[cpu].pps_stalled) /* !stalled */
4843                         continue;
4844
4845                 pm->pm_pcpu_state[cpu].pps_stalled = 0;
4846                 (*pcd->pcd_start_pmc)(cpu, adjri);
4847         }
4848 }
4849
4850 /*
4851  * Event handlers.
4852  */
4853
4854 /*
4855  * Handle a process exit.
4856  *
4857  * Remove this process from all hash tables.  If this process
4858  * owned any PMCs, turn off those PMCs and deallocate them,
4859  * removing any associations with target processes.
4860  *
4861  * This function will be called by the last 'thread' of a
4862  * process.
4863  *
4864  * XXX This eventhandler gets called early in the exit process.
4865  * Consider using a 'hook' invocation from thread_exit() or equivalent
4866  * spot.  Another negative is that kse_exit doesn't seem to call
4867  * exit1() [??].
4868  *
4869  */
4870
4871 static void
4872 pmc_process_exit(void *arg __unused, struct proc *p)
4873 {
4874         struct pmc *pm;
4875         int adjri, cpu;
4876         unsigned int ri;
4877         int is_using_hwpmcs;
4878         struct pmc_owner *po;
4879         struct pmc_process *pp;
4880         struct pmc_classdep *pcd;
4881         pmc_value_t newvalue, tmp;
4882
4883         PROC_LOCK(p);
4884         is_using_hwpmcs = p->p_flag & P_HWPMC;
4885         PROC_UNLOCK(p);
4886
4887         /*
4888          * Log a sysexit event to all SS PMC owners.
4889          */
4890         epoch_enter_preempt(global_epoch_preempt);
4891         CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext)
4892             if (po->po_flags & PMC_PO_OWNS_LOGFILE)
4893                     pmclog_process_sysexit(po, p->p_pid);
4894         epoch_exit_preempt(global_epoch_preempt);
4895
4896         if (!is_using_hwpmcs)
4897                 return;
4898
4899         PMC_GET_SX_XLOCK();
4900         PMCDBG3(PRC,EXT,1,"process-exit proc=%p (%d, %s)", p, p->p_pid,
4901             p->p_comm);
4902
4903         /*
4904          * Since this code is invoked by the last thread in an exiting
4905          * process, we would have context switched IN at some prior
4906          * point.  However, with PREEMPTION, kernel mode context
4907          * switches may happen any time, so we want to disable a
4908          * context switch OUT till we get any PMCs targeting this
4909          * process off the hardware.
4910          *
4911          * We also need to atomically remove this process'
4912          * entry from our target process hash table, using
4913          * PMC_FLAG_REMOVE.
4914          */
4915         PMCDBG3(PRC,EXT,1, "process-exit proc=%p (%d, %s)", p, p->p_pid,
4916             p->p_comm);
4917
4918         critical_enter(); /* no preemption */
4919
4920         cpu = curthread->td_oncpu;
4921
4922         if ((pp = pmc_find_process_descriptor(p,
4923                  PMC_FLAG_REMOVE)) != NULL) {
4924
4925                 PMCDBG2(PRC,EXT,2,
4926                     "process-exit proc=%p pmc-process=%p", p, pp);
4927
4928                 /*
4929                  * The exiting process could the target of
4930                  * some PMCs which will be running on
4931                  * currently executing CPU.
4932                  *
4933                  * We need to turn these PMCs off like we
4934                  * would do at context switch OUT time.
4935                  */
4936                 for (ri = 0; ri < md->pmd_npmc; ri++) {
4937
4938                         /*
4939                          * Pick up the pmc pointer from hardware
4940                          * state similar to the CSW_OUT code.
4941                          */
4942                         pm = NULL;
4943
4944                         pcd = pmc_ri_to_classdep(md, ri, &adjri);
4945
4946                         (void) (*pcd->pcd_get_config)(cpu, adjri, &pm);
4947
4948                         PMCDBG2(PRC,EXT,2, "ri=%d pm=%p", ri, pm);
4949
4950                         if (pm == NULL ||
4951                             !PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)))
4952                                 continue;
4953
4954                         PMCDBG4(PRC,EXT,2, "ppmcs[%d]=%p pm=%p "
4955                             "state=%d", ri, pp->pp_pmcs[ri].pp_pmc,
4956                             pm, pm->pm_state);
4957
4958                         KASSERT(PMC_TO_ROWINDEX(pm) == ri,
4959                             ("[pmc,%d] ri mismatch pmc(%d) ri(%d)",
4960                                 __LINE__, PMC_TO_ROWINDEX(pm), ri));
4961
4962                         KASSERT(pm == pp->pp_pmcs[ri].pp_pmc,
4963                             ("[pmc,%d] pm %p != pp_pmcs[%d] %p",
4964                                 __LINE__, pm, ri, pp->pp_pmcs[ri].pp_pmc));
4965
4966                         KASSERT(counter_u64_fetch(pm->pm_runcount) > 0,
4967                             ("[pmc,%d] bad runcount ri %d rc %ld",
4968                                  __LINE__, ri, (unsigned long)counter_u64_fetch(pm->pm_runcount)));
4969
4970                         /*
4971                          * Change desired state, and then stop if not
4972                          * stalled. This two-step dance should avoid
4973                          * race conditions where an interrupt re-enables
4974                          * the PMC after this code has already checked
4975                          * the pm_stalled flag.
4976                          */
4977                         if (pm->pm_pcpu_state[cpu].pps_cpustate) {
4978                                 pm->pm_pcpu_state[cpu].pps_cpustate = 0;
4979                                 if (!pm->pm_pcpu_state[cpu].pps_stalled) {
4980                                         (void) pcd->pcd_stop_pmc(cpu, adjri);
4981
4982                                         if (PMC_TO_MODE(pm) == PMC_MODE_TC) {
4983                                                 pcd->pcd_read_pmc(cpu, adjri,
4984                                                     &newvalue);
4985                                                 tmp = newvalue -
4986                                                     PMC_PCPU_SAVED(cpu,ri);
4987
4988                                                 mtx_pool_lock_spin(pmc_mtxpool,
4989                                                     pm);
4990                                                 pm->pm_gv.pm_savedvalue += tmp;
4991                                                 pp->pp_pmcs[ri].pp_pmcval +=
4992                                                     tmp;
4993                                                 mtx_pool_unlock_spin(
4994                                                     pmc_mtxpool, pm);
4995                                         }
4996                                 }
4997                         }
4998
4999                         counter_u64_add(pm->pm_runcount, -1);
5000
5001                         KASSERT((int) counter_u64_fetch(pm->pm_runcount) >= 0,
5002                             ("[pmc,%d] runcount is %d", __LINE__, ri));
5003
5004                         (void) pcd->pcd_config_pmc(cpu, adjri, NULL);
5005                 }
5006
5007                 /*
5008                  * Inform the MD layer of this pseudo "context switch
5009                  * out"
5010                  */
5011                 (void) md->pmd_switch_out(pmc_pcpu[cpu], pp);
5012
5013                 critical_exit(); /* ok to be pre-empted now */
5014
5015                 /*
5016                  * Unlink this process from the PMCs that are
5017                  * targeting it.  This will send a signal to
5018                  * all PMC owner's whose PMCs are orphaned.
5019                  *
5020                  * Log PMC value at exit time if requested.
5021                  */
5022                 for (ri = 0; ri < md->pmd_npmc; ri++)
5023                         if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) {
5024                                 if (pm->pm_flags & PMC_F_NEEDS_LOGFILE &&
5025                                     PMC_IS_COUNTING_MODE(PMC_TO_MODE(pm)))
5026                                         pmclog_process_procexit(pm, pp);
5027                                 pmc_unlink_target_process(pm, pp);
5028                         }
5029                 free(pp, M_PMC);
5030
5031         } else
5032                 critical_exit(); /* pp == NULL */
5033
5034
5035         /*
5036          * If the process owned PMCs, free them up and free up
5037          * memory.
5038          */
5039         if ((po = pmc_find_owner_descriptor(p)) != NULL) {
5040                 pmc_remove_owner(po);
5041                 pmc_destroy_owner_descriptor(po);
5042         }
5043
5044         sx_xunlock(&pmc_sx);
5045 }
5046
5047 /*
5048  * Handle a process fork.
5049  *
5050  * If the parent process 'p1' is under HWPMC monitoring, then copy
5051  * over any attached PMCs that have 'do_descendants' semantics.
5052  */
5053
5054 static void
5055 pmc_process_fork(void *arg __unused, struct proc *p1, struct proc *newproc,
5056     int flags)
5057 {
5058         int is_using_hwpmcs;
5059         unsigned int ri;
5060         uint32_t do_descendants;
5061         struct pmc *pm;
5062         struct pmc_owner *po;
5063         struct pmc_process *ppnew, *ppold;
5064
5065         (void) flags;           /* unused parameter */
5066
5067         PROC_LOCK(p1);
5068         is_using_hwpmcs = p1->p_flag & P_HWPMC;
5069         PROC_UNLOCK(p1);
5070
5071         /*
5072          * If there are system-wide sampling PMCs active, we need to
5073          * log all fork events to their owner's logs.
5074          */
5075         epoch_enter_preempt(global_epoch_preempt);
5076         CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext)
5077             if (po->po_flags & PMC_PO_OWNS_LOGFILE)
5078                     pmclog_process_procfork(po, p1->p_pid, newproc->p_pid);
5079         epoch_exit_preempt(global_epoch_preempt);
5080
5081         if (!is_using_hwpmcs)
5082                 return;
5083
5084         PMC_GET_SX_XLOCK();
5085         PMCDBG4(PMC,FRK,1, "process-fork proc=%p (%d, %s) -> %p", p1,
5086             p1->p_pid, p1->p_comm, newproc);
5087
5088         /*
5089          * If the parent process (curthread->td_proc) is a
5090          * target of any PMCs, look for PMCs that are to be
5091          * inherited, and link these into the new process
5092          * descriptor.
5093          */
5094         if ((ppold = pmc_find_process_descriptor(curthread->td_proc,
5095                  PMC_FLAG_NONE)) == NULL)
5096                 goto done;              /* nothing to do */
5097
5098         do_descendants = 0;
5099         for (ri = 0; ri < md->pmd_npmc; ri++)
5100                 if ((pm = ppold->pp_pmcs[ri].pp_pmc) != NULL)
5101                         do_descendants |= pm->pm_flags & PMC_F_DESCENDANTS;
5102         if (do_descendants == 0) /* nothing to do */
5103                 goto done;
5104
5105         /*
5106          * Now mark the new process as being tracked by this driver.
5107          */
5108         PROC_LOCK(newproc);
5109         newproc->p_flag |= P_HWPMC;
5110         PROC_UNLOCK(newproc);
5111
5112         /* allocate a descriptor for the new process  */
5113         if ((ppnew = pmc_find_process_descriptor(newproc,
5114                  PMC_FLAG_ALLOCATE)) == NULL)
5115                 goto done;
5116
5117         /*
5118          * Run through all PMCs that were targeting the old process
5119          * and which specified F_DESCENDANTS and attach them to the
5120          * new process.
5121          *
5122          * Log the fork event to all owners of PMCs attached to this
5123          * process, if not already logged.
5124          */
5125         for (ri = 0; ri < md->pmd_npmc; ri++)
5126                 if ((pm = ppold->pp_pmcs[ri].pp_pmc) != NULL &&
5127                     (pm->pm_flags & PMC_F_DESCENDANTS)) {
5128                         pmc_link_target_process(pm, ppnew);
5129                         po = pm->pm_owner;
5130                         if (po->po_sscount == 0 &&
5131                             po->po_flags & PMC_PO_OWNS_LOGFILE)
5132                                 pmclog_process_procfork(po, p1->p_pid,
5133                                     newproc->p_pid);
5134                 }
5135
5136  done:
5137         sx_xunlock(&pmc_sx);
5138 }
5139
5140 static void
5141 pmc_kld_load(void *arg __unused, linker_file_t lf)
5142 {
5143         struct pmc_owner *po;
5144
5145         /*
5146          * Notify owners of system sampling PMCs about KLD operations.
5147          */
5148         epoch_enter_preempt(global_epoch_preempt);
5149         CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext)
5150                 if (po->po_flags & PMC_PO_OWNS_LOGFILE)
5151                         pmclog_process_map_in(po, (pid_t) -1,
5152                             (uintfptr_t) lf->address, lf->filename);
5153         epoch_exit_preempt(global_epoch_preempt);
5154
5155         /*
5156          * TODO: Notify owners of (all) process-sampling PMCs too.
5157          */
5158 }
5159
5160 static void
5161 pmc_kld_unload(void *arg __unused, const char *filename __unused,
5162     caddr_t address, size_t size)
5163 {
5164         struct pmc_owner *po;
5165
5166         epoch_enter_preempt(global_epoch_preempt);
5167         CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext)
5168                 if (po->po_flags & PMC_PO_OWNS_LOGFILE)
5169                         pmclog_process_map_out(po, (pid_t) -1,
5170                             (uintfptr_t) address, (uintfptr_t) address + size);
5171         epoch_exit_preempt(global_epoch_preempt);
5172
5173         /*
5174          * TODO: Notify owners of process-sampling PMCs.
5175          */
5176 }
5177
5178 /*
5179  * initialization
5180  */
5181 static const char *
5182 pmc_name_of_pmcclass(enum pmc_class class)
5183 {
5184
5185         switch (class) {
5186 #undef  __PMC_CLASS
5187 #define __PMC_CLASS(S,V,D)                                              \
5188         case PMC_CLASS_##S:                                             \
5189                 return #S;
5190         __PMC_CLASSES();
5191         default:
5192                 return ("<unknown>");
5193         }
5194 }
5195
5196 /*
5197  * Base class initializer: allocate structure and set default classes.
5198  */
5199 struct pmc_mdep *
5200 pmc_mdep_alloc(int nclasses)
5201 {
5202         struct pmc_mdep *md;
5203         int     n;
5204
5205         /* SOFT + md classes */
5206         n = 1 + nclasses;
5207         md = malloc(sizeof(struct pmc_mdep) + n *
5208             sizeof(struct pmc_classdep), M_PMC, M_WAITOK|M_ZERO);
5209         md->pmd_nclass = n;
5210
5211         /* Add base class. */
5212         pmc_soft_initialize(md);
5213         return md;
5214 }
5215
5216 void
5217 pmc_mdep_free(struct pmc_mdep *md)
5218 {
5219         pmc_soft_finalize(md);
5220         free(md, M_PMC);
5221 }
5222
5223 static int
5224 generic_switch_in(struct pmc_cpu *pc, struct pmc_process *pp)
5225 {
5226         (void) pc; (void) pp;
5227
5228         return (0);
5229 }
5230
5231 static int
5232 generic_switch_out(struct pmc_cpu *pc, struct pmc_process *pp)
5233 {
5234         (void) pc; (void) pp;
5235
5236         return (0);
5237 }
5238
5239 static struct pmc_mdep *
5240 pmc_generic_cpu_initialize(void)
5241 {
5242         struct pmc_mdep *md;
5243
5244         md = pmc_mdep_alloc(0);
5245
5246         md->pmd_cputype    = PMC_CPU_GENERIC;
5247
5248         md->pmd_pcpu_init  = NULL;
5249         md->pmd_pcpu_fini  = NULL;
5250         md->pmd_switch_in  = generic_switch_in;
5251         md->pmd_switch_out = generic_switch_out;
5252
5253         return (md);
5254 }
5255
5256 static void
5257 pmc_generic_cpu_finalize(struct pmc_mdep *md)
5258 {
5259         (void) md;
5260 }
5261
5262
5263 static int
5264 pmc_initialize(void)
5265 {
5266         int c, cpu, error, n, ri;
5267         unsigned int maxcpu, domain;
5268         struct pcpu *pc;
5269         struct pmc_binding pb;
5270         struct pmc_sample *ps;
5271         struct pmc_classdep *pcd;
5272         struct pmc_samplebuffer *sb;
5273
5274         md = NULL;
5275         error = 0;
5276
5277         pmc_stats.pm_intr_ignored = counter_u64_alloc(M_WAITOK);
5278         pmc_stats.pm_intr_processed = counter_u64_alloc(M_WAITOK);
5279         pmc_stats.pm_intr_bufferfull = counter_u64_alloc(M_WAITOK);
5280         pmc_stats.pm_syscalls = counter_u64_alloc(M_WAITOK);
5281         pmc_stats.pm_syscall_errors = counter_u64_alloc(M_WAITOK);
5282         pmc_stats.pm_buffer_requests = counter_u64_alloc(M_WAITOK);
5283         pmc_stats.pm_buffer_requests_failed = counter_u64_alloc(M_WAITOK);
5284         pmc_stats.pm_log_sweeps = counter_u64_alloc(M_WAITOK);
5285
5286 #ifdef  HWPMC_DEBUG
5287         /* parse debug flags first */
5288         if (TUNABLE_STR_FETCH(PMC_SYSCTL_NAME_PREFIX "debugflags",
5289                 pmc_debugstr, sizeof(pmc_debugstr)))
5290                 pmc_debugflags_parse(pmc_debugstr,
5291                     pmc_debugstr+strlen(pmc_debugstr));
5292 #endif
5293
5294         PMCDBG1(MOD,INI,0, "PMC Initialize (version %x)", PMC_VERSION);
5295
5296         /* check kernel version */
5297         if (pmc_kernel_version != PMC_VERSION) {
5298                 if (pmc_kernel_version == 0)
5299                         printf("hwpmc: this kernel has not been compiled with "
5300                             "'options HWPMC_HOOKS'.\n");
5301                 else
5302                         printf("hwpmc: kernel version (0x%x) does not match "
5303                             "module version (0x%x).\n", pmc_kernel_version,
5304                             PMC_VERSION);
5305                 return EPROGMISMATCH;
5306         }
5307
5308         /*
5309          * check sysctl parameters
5310          */
5311
5312         if (pmc_hashsize <= 0) {
5313                 (void) printf("hwpmc: tunable \"hashsize\"=%d must be "
5314                     "greater than zero.\n", pmc_hashsize);
5315                 pmc_hashsize = PMC_HASH_SIZE;
5316         }
5317
5318         if (pmc_nsamples <= 0 || pmc_nsamples > 65535) {
5319                 (void) printf("hwpmc: tunable \"nsamples\"=%d out of "
5320                     "range.\n", pmc_nsamples);
5321                 pmc_nsamples = PMC_NSAMPLES;
5322         }
5323
5324         if (pmc_callchaindepth <= 0 ||
5325             pmc_callchaindepth > PMC_CALLCHAIN_DEPTH_MAX) {
5326                 (void) printf("hwpmc: tunable \"callchaindepth\"=%d out of "
5327                     "range - using %d.\n", pmc_callchaindepth,
5328                     PMC_CALLCHAIN_DEPTH_MAX);
5329                 pmc_callchaindepth = PMC_CALLCHAIN_DEPTH_MAX;
5330         }
5331
5332         md = pmc_md_initialize();
5333         if (md == NULL) {
5334                 /* Default to generic CPU. */
5335                 md = pmc_generic_cpu_initialize();
5336                 if (md == NULL)
5337                         return (ENOSYS);
5338         }
5339
5340         KASSERT(md->pmd_nclass >= 1 && md->pmd_npmc >= 1,
5341             ("[pmc,%d] no classes or pmcs", __LINE__));
5342
5343         /* Compute the map from row-indices to classdep pointers. */
5344         pmc_rowindex_to_classdep = malloc(sizeof(struct pmc_classdep *) *
5345             md->pmd_npmc, M_PMC, M_WAITOK|M_ZERO);
5346
5347         for (n = 0; n < md->pmd_npmc; n++)
5348                 pmc_rowindex_to_classdep[n] = NULL;
5349         for (ri = c = 0; c < md->pmd_nclass; c++) {
5350                 pcd = &md->pmd_classdep[c];
5351                 for (n = 0; n < pcd->pcd_num; n++, ri++)
5352                         pmc_rowindex_to_classdep[ri] = pcd;
5353         }
5354
5355         KASSERT(ri == md->pmd_npmc,
5356             ("[pmc,%d] npmc miscomputed: ri=%d, md->npmc=%d", __LINE__,
5357             ri, md->pmd_npmc));
5358
5359         maxcpu = pmc_cpu_max();
5360
5361         /* allocate space for the per-cpu array */
5362         pmc_pcpu = malloc(maxcpu * sizeof(struct pmc_cpu *), M_PMC,
5363             M_WAITOK|M_ZERO);
5364
5365         /* per-cpu 'saved values' for managing process-mode PMCs */
5366         pmc_pcpu_saved = malloc(sizeof(pmc_value_t) * maxcpu * md->pmd_npmc,
5367             M_PMC, M_WAITOK);
5368
5369         /* Perform CPU-dependent initialization. */
5370         pmc_save_cpu_binding(&pb);
5371         error = 0;
5372         for (cpu = 0; error == 0 && cpu < maxcpu; cpu++) {
5373                 if (!pmc_cpu_is_active(cpu))
5374                         continue;
5375                 pmc_select_cpu(cpu);
5376                 pmc_pcpu[cpu] = malloc(sizeof(struct pmc_cpu) +
5377                     md->pmd_npmc * sizeof(struct pmc_hw *), M_PMC,
5378                     M_WAITOK|M_ZERO);
5379                 if (md->pmd_pcpu_init)
5380                         error = md->pmd_pcpu_init(md, cpu);
5381                 for (n = 0; error == 0 && n < md->pmd_nclass; n++)
5382                         error = md->pmd_classdep[n].pcd_pcpu_init(md, cpu);
5383         }
5384         pmc_restore_cpu_binding(&pb);
5385
5386         if (error)
5387                 return (error);
5388
5389         /* allocate space for the sample array */
5390         for (cpu = 0; cpu < maxcpu; cpu++) {
5391                 if (!pmc_cpu_is_active(cpu))
5392                         continue;
5393                 pc = pcpu_find(cpu);
5394                 domain = pc->pc_domain;
5395                 sb = malloc_domain(sizeof(struct pmc_samplebuffer) +
5396                         pmc_nsamples * sizeof(struct pmc_sample), M_PMC, domain,
5397                     M_WAITOK|M_ZERO);
5398                 sb->ps_read = sb->ps_write = sb->ps_samples;
5399                 sb->ps_fence = sb->ps_samples + pmc_nsamples;
5400
5401                 KASSERT(pmc_pcpu[cpu] != NULL,
5402                     ("[pmc,%d] cpu=%d Null per-cpu data", __LINE__, cpu));
5403
5404                 sb->ps_callchains = malloc_domain(pmc_callchaindepth * pmc_nsamples *
5405                         sizeof(uintptr_t), M_PMC, domain, M_WAITOK|M_ZERO);
5406
5407                 for (n = 0, ps = sb->ps_samples; n < pmc_nsamples; n++, ps++)
5408                         ps->ps_pc = sb->ps_callchains +
5409                             (n * pmc_callchaindepth);
5410
5411                 pmc_pcpu[cpu]->pc_sb[PMC_HR] = sb;
5412
5413                 sb = malloc_domain(sizeof(struct pmc_samplebuffer) +
5414                         pmc_nsamples * sizeof(struct pmc_sample), M_PMC, domain,
5415                     M_WAITOK|M_ZERO);
5416                 sb->ps_read = sb->ps_write = sb->ps_samples;
5417                 sb->ps_fence = sb->ps_samples + pmc_nsamples;
5418
5419                 KASSERT(pmc_pcpu[cpu] != NULL,
5420                     ("[pmc,%d] cpu=%d Null per-cpu data", __LINE__, cpu));
5421
5422                 sb->ps_callchains = malloc_domain(pmc_callchaindepth * pmc_nsamples *
5423                         sizeof(uintptr_t), M_PMC, domain, M_WAITOK|M_ZERO);
5424
5425                 for (n = 0, ps = sb->ps_samples; n < pmc_nsamples; n++, ps++)
5426                         ps->ps_pc = sb->ps_callchains +
5427                             (n * pmc_callchaindepth);
5428
5429                 pmc_pcpu[cpu]->pc_sb[PMC_SR] = sb;
5430         }
5431
5432         /* allocate space for the row disposition array */
5433         pmc_pmcdisp = malloc(sizeof(enum pmc_mode) * md->pmd_npmc,
5434             M_PMC, M_WAITOK|M_ZERO);
5435
5436         /* mark all PMCs as available */
5437         for (n = 0; n < (int) md->pmd_npmc; n++)
5438                 PMC_MARK_ROW_FREE(n);
5439
5440         /* allocate thread hash tables */
5441         pmc_ownerhash = hashinit(pmc_hashsize, M_PMC,
5442             &pmc_ownerhashmask);
5443
5444         pmc_processhash = hashinit(pmc_hashsize, M_PMC,
5445             &pmc_processhashmask);
5446         mtx_init(&pmc_processhash_mtx, "pmc-process-hash", "pmc-leaf",
5447             MTX_SPIN);
5448
5449         CK_LIST_INIT(&pmc_ss_owners);
5450         pmc_ss_count = 0;
5451
5452         /* allocate a pool of spin mutexes */
5453         pmc_mtxpool = mtx_pool_create("pmc-leaf", pmc_mtxpool_size,
5454             MTX_SPIN);
5455
5456         PMCDBG4(MOD,INI,1, "pmc_ownerhash=%p, mask=0x%lx "
5457             "targethash=%p mask=0x%lx", pmc_ownerhash, pmc_ownerhashmask,
5458             pmc_processhash, pmc_processhashmask);
5459
5460         /* Initialize a spin mutex for the thread free list. */
5461         mtx_init(&pmc_threadfreelist_mtx, "pmc-threadfreelist", "pmc-leaf",
5462             MTX_SPIN);
5463
5464         /*
5465          * Initialize the callout to monitor the thread free list.
5466          * This callout will also handle the initial population of the list.
5467          */
5468         taskqgroup_config_gtask_init(NULL, &free_gtask, pmc_thread_descriptor_pool_free_task, "thread descriptor pool free task");
5469
5470         /* register process {exit,fork,exec} handlers */
5471         pmc_exit_tag = EVENTHANDLER_REGISTER(process_exit,
5472             pmc_process_exit, NULL, EVENTHANDLER_PRI_ANY);
5473         pmc_fork_tag = EVENTHANDLER_REGISTER(process_fork,
5474             pmc_process_fork, NULL, EVENTHANDLER_PRI_ANY);
5475
5476         /* register kld event handlers */
5477         pmc_kld_load_tag = EVENTHANDLER_REGISTER(kld_load, pmc_kld_load,
5478             NULL, EVENTHANDLER_PRI_ANY);
5479         pmc_kld_unload_tag = EVENTHANDLER_REGISTER(kld_unload, pmc_kld_unload,
5480             NULL, EVENTHANDLER_PRI_ANY);
5481
5482         /* initialize logging */
5483         pmclog_initialize();
5484
5485         /* set hook functions */
5486         pmc_intr = md->pmd_intr;
5487         wmb();
5488         pmc_hook = pmc_hook_handler;
5489
5490         if (error == 0) {
5491                 printf(PMC_MODULE_NAME ":");
5492                 for (n = 0; n < (int) md->pmd_nclass; n++) {
5493                         pcd = &md->pmd_classdep[n];
5494                         printf(" %s/%d/%d/0x%b",
5495                             pmc_name_of_pmcclass(pcd->pcd_class),
5496                             pcd->pcd_num,
5497                             pcd->pcd_width,
5498                             pcd->pcd_caps,
5499                             "\20"
5500                             "\1INT\2USR\3SYS\4EDG\5THR"
5501                             "\6REA\7WRI\10INV\11QUA\12PRC"
5502                             "\13TAG\14CSC");
5503                 }
5504                 printf("\n");
5505         }
5506
5507         return (error);
5508 }
5509
5510 /* prepare to be unloaded */
5511 static void
5512 pmc_cleanup(void)
5513 {
5514         int c, cpu;
5515         unsigned int maxcpu;
5516         struct pmc_ownerhash *ph;
5517         struct pmc_owner *po, *tmp;
5518         struct pmc_binding pb;
5519 #ifdef  HWPMC_DEBUG
5520         struct pmc_processhash *prh;
5521 #endif
5522
5523         PMCDBG0(MOD,INI,0, "cleanup");
5524
5525         /* switch off sampling */
5526         CPU_FOREACH(cpu)
5527                 DPCPU_ID_SET(cpu, pmc_sampled, 0);
5528         pmc_intr = NULL;
5529
5530         sx_xlock(&pmc_sx);
5531         if (pmc_hook == NULL) { /* being unloaded already */
5532                 sx_xunlock(&pmc_sx);
5533                 return;
5534         }
5535
5536         pmc_hook = NULL; /* prevent new threads from entering module */
5537
5538         /* deregister event handlers */
5539         EVENTHANDLER_DEREGISTER(process_fork, pmc_fork_tag);
5540         EVENTHANDLER_DEREGISTER(process_exit, pmc_exit_tag);
5541         EVENTHANDLER_DEREGISTER(kld_load, pmc_kld_load_tag);
5542         EVENTHANDLER_DEREGISTER(kld_unload, pmc_kld_unload_tag);
5543
5544         /* send SIGBUS to all owner threads, free up allocations */
5545         if (pmc_ownerhash)
5546                 for (ph = pmc_ownerhash;
5547                      ph <= &pmc_ownerhash[pmc_ownerhashmask];
5548                      ph++) {
5549                         LIST_FOREACH_SAFE(po, ph, po_next, tmp) {
5550                                 pmc_remove_owner(po);
5551
5552                                 /* send SIGBUS to owner processes */
5553                                 PMCDBG3(MOD,INI,2, "cleanup signal proc=%p "
5554                                     "(%d, %s)", po->po_owner,
5555                                     po->po_owner->p_pid,
5556                                     po->po_owner->p_comm);
5557
5558                                 PROC_LOCK(po->po_owner);
5559                                 kern_psignal(po->po_owner, SIGBUS);
5560                                 PROC_UNLOCK(po->po_owner);
5561
5562                                 pmc_destroy_owner_descriptor(po);
5563                         }
5564                 }
5565
5566         /* reclaim allocated data structures */
5567         mtx_destroy(&pmc_threadfreelist_mtx);
5568         pmc_thread_descriptor_pool_drain();
5569
5570         if (pmc_mtxpool)
5571                 mtx_pool_destroy(&pmc_mtxpool);
5572
5573         mtx_destroy(&pmc_processhash_mtx);
5574         taskqgroup_config_gtask_deinit(&free_gtask);
5575         if (pmc_processhash) {
5576 #ifdef  HWPMC_DEBUG
5577                 struct pmc_process *pp;
5578
5579                 PMCDBG0(MOD,INI,3, "destroy process hash");
5580                 for (prh = pmc_processhash;
5581                      prh <= &pmc_processhash[pmc_processhashmask];
5582                      prh++)
5583                         LIST_FOREACH(pp, prh, pp_next)
5584                             PMCDBG1(MOD,INI,3, "pid=%d", pp->pp_proc->p_pid);
5585 #endif
5586
5587                 hashdestroy(pmc_processhash, M_PMC, pmc_processhashmask);
5588                 pmc_processhash = NULL;
5589         }
5590
5591         if (pmc_ownerhash) {
5592                 PMCDBG0(MOD,INI,3, "destroy owner hash");
5593                 hashdestroy(pmc_ownerhash, M_PMC, pmc_ownerhashmask);
5594                 pmc_ownerhash = NULL;
5595         }
5596
5597         KASSERT(CK_LIST_EMPTY(&pmc_ss_owners),
5598             ("[pmc,%d] Global SS owner list not empty", __LINE__));
5599         KASSERT(pmc_ss_count == 0,
5600             ("[pmc,%d] Global SS count not empty", __LINE__));
5601
5602         /* do processor and pmc-class dependent cleanup */
5603         maxcpu = pmc_cpu_max();
5604
5605         PMCDBG0(MOD,INI,3, "md cleanup");
5606         if (md) {
5607                 pmc_save_cpu_binding(&pb);
5608                 for (cpu = 0; cpu < maxcpu; cpu++) {
5609                         PMCDBG2(MOD,INI,1,"pmc-cleanup cpu=%d pcs=%p",
5610                             cpu, pmc_pcpu[cpu]);
5611                         if (!pmc_cpu_is_active(cpu) || pmc_pcpu[cpu] == NULL)
5612                                 continue;
5613                         pmc_select_cpu(cpu);
5614                         for (c = 0; c < md->pmd_nclass; c++)
5615                                 md->pmd_classdep[c].pcd_pcpu_fini(md, cpu);
5616                         if (md->pmd_pcpu_fini)
5617                                 md->pmd_pcpu_fini(md, cpu);
5618                 }
5619
5620                 if (md->pmd_cputype == PMC_CPU_GENERIC)
5621                         pmc_generic_cpu_finalize(md);
5622                 else
5623                         pmc_md_finalize(md);
5624
5625                 pmc_mdep_free(md);
5626                 md = NULL;
5627                 pmc_restore_cpu_binding(&pb);
5628         }
5629
5630         /* Free per-cpu descriptors. */
5631         for (cpu = 0; cpu < maxcpu; cpu++) {
5632                 if (!pmc_cpu_is_active(cpu))
5633                         continue;
5634                 KASSERT(pmc_pcpu[cpu]->pc_sb[PMC_HR] != NULL,
5635                     ("[pmc,%d] Null hw cpu sample buffer cpu=%d", __LINE__,
5636                         cpu));
5637                 KASSERT(pmc_pcpu[cpu]->pc_sb[PMC_SR] != NULL,
5638                     ("[pmc,%d] Null sw cpu sample buffer cpu=%d", __LINE__,
5639                         cpu));
5640                 free_domain(pmc_pcpu[cpu]->pc_sb[PMC_HR]->ps_callchains, M_PMC);
5641                 free_domain(pmc_pcpu[cpu]->pc_sb[PMC_HR], M_PMC);
5642                 free_domain(pmc_pcpu[cpu]->pc_sb[PMC_SR]->ps_callchains, M_PMC);
5643                 free_domain(pmc_pcpu[cpu]->pc_sb[PMC_SR], M_PMC);
5644                 free_domain(pmc_pcpu[cpu], M_PMC);
5645         }
5646
5647         free(pmc_pcpu, M_PMC);
5648         pmc_pcpu = NULL;
5649
5650         free(pmc_pcpu_saved, M_PMC);
5651         pmc_pcpu_saved = NULL;
5652
5653         if (pmc_pmcdisp) {
5654                 free(pmc_pmcdisp, M_PMC);
5655                 pmc_pmcdisp = NULL;
5656         }
5657
5658         if (pmc_rowindex_to_classdep) {
5659                 free(pmc_rowindex_to_classdep, M_PMC);
5660                 pmc_rowindex_to_classdep = NULL;
5661         }
5662
5663         pmclog_shutdown();
5664         counter_u64_free(pmc_stats.pm_intr_ignored);
5665         counter_u64_free(pmc_stats.pm_intr_processed);
5666         counter_u64_free(pmc_stats.pm_intr_bufferfull);
5667         counter_u64_free(pmc_stats.pm_syscalls);
5668         counter_u64_free(pmc_stats.pm_syscall_errors);
5669         counter_u64_free(pmc_stats.pm_buffer_requests);
5670         counter_u64_free(pmc_stats.pm_buffer_requests_failed);
5671         counter_u64_free(pmc_stats.pm_log_sweeps);
5672         sx_xunlock(&pmc_sx);    /* we are done */
5673 }
5674
5675 /*
5676  * The function called at load/unload.
5677  */
5678
5679 static int
5680 load (struct module *module __unused, int cmd, void *arg __unused)
5681 {
5682         int error;
5683
5684         error = 0;
5685
5686         switch (cmd) {
5687         case MOD_LOAD :
5688                 /* initialize the subsystem */
5689                 error = pmc_initialize();
5690                 if (error != 0)
5691                         break;
5692                 PMCDBG2(MOD,INI,1, "syscall=%d maxcpu=%d",
5693                     pmc_syscall_num, pmc_cpu_max());
5694                 break;
5695
5696
5697         case MOD_UNLOAD :
5698         case MOD_SHUTDOWN:
5699                 pmc_cleanup();
5700                 PMCDBG0(MOD,INI,1, "unloaded");
5701                 break;
5702
5703         default :
5704                 error = EINVAL; /* XXX should panic(9) */
5705                 break;
5706         }
5707
5708         return error;
5709 }