sys/kern/sys_process.c

   1 /*-
   2  * Copyright (c) 1994, Sean Eric Fagan
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by Sean Eric Fagan.
  16  * 4. The name of the author may not be used to endorse or promote products
  17  *    derived from this software without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  */
  31
  32 #include <sys/cdefs.h>
  33 __FBSDID("$FreeBSD$");
  34
  35 #include "opt_compat.h"
  36
  37 #include <sys/param.h>
  38 #include <sys/systm.h>
  39 #include <sys/lock.h>
  40 #include <sys/mutex.h>
  41 #include <sys/syscallsubr.h>
  42 #include <sys/sysent.h>
  43 #include <sys/sysproto.h>
  44 #include <sys/priv.h>
  45 #include <sys/proc.h>
  46 #include <sys/vnode.h>
  47 #include <sys/ptrace.h>
  48 #include <sys/rwlock.h>
  49 #include <sys/sx.h>
  50 #include <sys/malloc.h>
  51 #include <sys/signalvar.h>
  52
  53 #include <machine/reg.h>
  54
  55 #include <security/audit/audit.h>
  56
  57 #include <vm/vm.h>
  58 #include <vm/pmap.h>
  59 #include <vm/vm_extern.h>
  60 #include <vm/vm_map.h>
  61 #include <vm/vm_kern.h>
  62 #include <vm/vm_object.h>
  63 #include <vm/vm_page.h>
  64 #include <vm/vm_param.h>
  65
  66 #ifdef COMPAT_FREEBSD32
  67 #include <sys/procfs.h>
  68 #include <compat/freebsd32/freebsd32_signal.h>
  69
  70 struct ptrace_io_desc32 {
  71         int             piod_op;
  72         uint32_t        piod_offs;
  73         uint32_t        piod_addr;
  74         uint32_t        piod_len;
  75 };
  76
  77 struct ptrace_vm_entry32 {
  78         int             pve_entry;
  79         int             pve_timestamp;
  80         uint32_t        pve_start;
  81         uint32_t        pve_end;
  82         uint32_t        pve_offset;
  83         u_int           pve_prot;
  84         u_int           pve_pathlen;
  85         int32_t         pve_fileid;
  86         u_int           pve_fsid;
  87         uint32_t        pve_path;
  88 };
  89
  90 struct ptrace_lwpinfo32 {
  91         lwpid_t pl_lwpid;       /* LWP described. */
  92         int     pl_event;       /* Event that stopped the LWP. */
  93         int     pl_flags;       /* LWP flags. */
  94         sigset_t        pl_sigmask;     /* LWP signal mask */
  95         sigset_t        pl_siglist;     /* LWP pending signal */
  96         struct siginfo32 pl_siginfo;    /* siginfo for signal */
  97         char    pl_tdname[MAXCOMLEN + 1];       /* LWP name. */
  98         pid_t   pl_child_pid;           /* New child pid */
  99         u_int           pl_syscall_code;
 100         u_int           pl_syscall_narg;
 101 };
 102
 103 #endif
 104
 105 /*
 106  * Functions implemented using PROC_ACTION():
 107  *
 108  * proc_read_regs(proc, regs)
 109  *      Get the current user-visible register set from the process
 110  *      and copy it into the regs structure (<machine/reg.h>).
 111  *      The process is stopped at the time read_regs is called.
 112  *
 113  * proc_write_regs(proc, regs)
 114  *      Update the current register set from the passed in regs
 115  *      structure.  Take care to avoid clobbering special CPU
 116  *      registers or privileged bits in the PSL.
 117  *      Depending on the architecture this may have fix-up work to do,
 118  *      especially if the IAR or PCW are modified.
 119  *      The process is stopped at the time write_regs is called.
 120  *
 121  * proc_read_fpregs, proc_write_fpregs
 122  *      deal with the floating point register set, otherwise as above.
 123  *
 124  * proc_read_dbregs, proc_write_dbregs
 125  *      deal with the processor debug register set, otherwise as above.
 126  *
 127  * proc_sstep(proc)
 128  *      Arrange for the process to trap after executing a single instruction.
 129  */
 130
 131 #define PROC_ACTION(action) do {                                        \
 132         int error;                                                      \
 133                                                                         \
 134         PROC_LOCK_ASSERT(td->td_proc, MA_OWNED);                        \
 135         if ((td->td_proc->p_flag & P_INMEM) == 0)                       \
 136                 error = EIO;                                            \
 137         else                                                            \
 138                 error = (action);                                       \
 139         return (error);                                                 \
 140 } while(0)
 141
 142 int
 143 proc_read_regs(struct thread *td, struct reg *regs)
 144 {
 145
 146         PROC_ACTION(fill_regs(td, regs));
 147 }
 148
 149 int
 150 proc_write_regs(struct thread *td, struct reg *regs)
 151 {
 152
 153         PROC_ACTION(set_regs(td, regs));
 154 }
 155
 156 int
 157 proc_read_dbregs(struct thread *td, struct dbreg *dbregs)
 158 {
 159
 160         PROC_ACTION(fill_dbregs(td, dbregs));
 161 }
 162
 163 int
 164 proc_write_dbregs(struct thread *td, struct dbreg *dbregs)
 165 {
 166
 167         PROC_ACTION(set_dbregs(td, dbregs));
 168 }
 169
 170 /*
 171  * Ptrace doesn't support fpregs at all, and there are no security holes
 172  * or translations for fpregs, so we can just copy them.
 173  */
 174 int
 175 proc_read_fpregs(struct thread *td, struct fpreg *fpregs)
 176 {
 177
 178         PROC_ACTION(fill_fpregs(td, fpregs));
 179 }
 180
 181 int
 182 proc_write_fpregs(struct thread *td, struct fpreg *fpregs)
 183 {
 184
 185         PROC_ACTION(set_fpregs(td, fpregs));
 186 }
 187
 188 #ifdef COMPAT_FREEBSD32
 189 /* For 32 bit binaries, we need to expose the 32 bit regs layouts. */
 190 int
 191 proc_read_regs32(struct thread *td, struct reg32 *regs32)
 192 {
 193
 194         PROC_ACTION(fill_regs32(td, regs32));
 195 }
 196
 197 int
 198 proc_write_regs32(struct thread *td, struct reg32 *regs32)
 199 {
 200
 201         PROC_ACTION(set_regs32(td, regs32));
 202 }
 203
 204 int
 205 proc_read_dbregs32(struct thread *td, struct dbreg32 *dbregs32)
 206 {
 207
 208         PROC_ACTION(fill_dbregs32(td, dbregs32));
 209 }
 210
 211 int
 212 proc_write_dbregs32(struct thread *td, struct dbreg32 *dbregs32)
 213 {
 214
 215         PROC_ACTION(set_dbregs32(td, dbregs32));
 216 }
 217
 218 int
 219 proc_read_fpregs32(struct thread *td, struct fpreg32 *fpregs32)
 220 {
 221
 222         PROC_ACTION(fill_fpregs32(td, fpregs32));
 223 }
 224
 225 int
 226 proc_write_fpregs32(struct thread *td, struct fpreg32 *fpregs32)
 227 {
 228
 229         PROC_ACTION(set_fpregs32(td, fpregs32));
 230 }
 231 #endif
 232
 233 int
 234 proc_sstep(struct thread *td)
 235 {
 236
 237         PROC_ACTION(ptrace_single_step(td));
 238 }
 239
 240 int
 241 proc_rwmem(struct proc *p, struct uio *uio)
 242 {
 243         vm_map_t map;
 244         vm_offset_t pageno;             /* page number */
 245         vm_prot_t reqprot;
 246         int error, fault_flags, page_offset, writing;
 247
 248         /*
 249          * Assert that someone has locked this vmspace.  (Should be
 250          * curthread but we can't assert that.)  This keeps the process
 251          * from exiting out from under us until this operation completes.
 252          */
 253         KASSERT(p->p_lock >= 1, ("%s: process %p (pid %d) not held", __func__,
 254             p, p->p_pid));
 255
 256         /*
 257          * The map we want...
 258          */
 259         map = &p->p_vmspace->vm_map;
 260
 261         /*
 262          * If we are writing, then we request vm_fault() to create a private
 263          * copy of each page.  Since these copies will not be writeable by the
 264          * process, we must explicity request that they be dirtied.
 265          */
 266         writing = uio->uio_rw == UIO_WRITE;
 267         reqprot = writing ? VM_PROT_COPY | VM_PROT_READ : VM_PROT_READ;
 268         fault_flags = writing ? VM_FAULT_DIRTY : VM_FAULT_NORMAL;
 269
 270         /*
 271          * Only map in one page at a time.  We don't have to, but it
 272          * makes things easier.  This way is trivial - right?
 273          */
 274         do {
 275                 vm_offset_t uva;
 276                 u_int len;
 277                 vm_page_t m;
 278
 279                 uva = (vm_offset_t)uio->uio_offset;
 280
 281                 /*
 282                  * Get the page number of this segment.
 283                  */
 284                 pageno = trunc_page(uva);
 285                 page_offset = uva - pageno;
 286
 287                 /*
 288                  * How many bytes to copy
 289                  */
 290                 len = min(PAGE_SIZE - page_offset, uio->uio_resid);
 291
 292                 /*
 293                  * Fault and hold the page on behalf of the process.
 294                  */
 295                 error = vm_fault_hold(map, pageno, reqprot, fault_flags, &m);
 296                 if (error != KERN_SUCCESS) {
 297                         if (error == KERN_RESOURCE_SHORTAGE)
 298                                 error = ENOMEM;
 299                         else
 300                                 error = EFAULT;
 301                         break;
 302                 }
 303
 304                 /*
 305                  * Now do the i/o move.
 306                  */
 307                 error = uiomove_fromphys(&m, page_offset, len, uio);
 308
 309                 /* Make the I-cache coherent for breakpoints. */
 310                 if (writing && error == 0) {
 311                         vm_map_lock_read(map);
 312                         if (vm_map_check_protection(map, pageno, pageno +
 313                             PAGE_SIZE, VM_PROT_EXECUTE))
 314                                 vm_sync_icache(map, uva, len);
 315                         vm_map_unlock_read(map);
 316                 }
 317
 318                 /*
 319                  * Release the page.
 320                  */
 321                 vm_page_lock(m);
 322                 vm_page_unhold(m);
 323                 vm_page_unlock(m);
 324
 325         } while (error == 0 && uio->uio_resid > 0);
 326
 327         return (error);
 328 }
 329
 330 static int
 331 ptrace_vm_entry(struct thread *td, struct proc *p, struct ptrace_vm_entry *pve)
 332 {
 333         struct vattr vattr;
 334         vm_map_t map;
 335         vm_map_entry_t entry;
 336         vm_object_t obj, tobj, lobj;
 337         struct vmspace *vm;
 338         struct vnode *vp;
 339         char *freepath, *fullpath;
 340         u_int pathlen;
 341         int error, index;
 342
 343         error = 0;
 344         obj = NULL;
 345
 346         vm = vmspace_acquire_ref(p);
 347         map = &vm->vm_map;
 348         vm_map_lock_read(map);
 349
 350         do {
 351                 entry = map->header.next;
 352                 index = 0;
 353                 while (index < pve->pve_entry && entry != &map->header) {
 354                         entry = entry->next;
 355                         index++;
 356                 }
 357                 if (index != pve->pve_entry) {
 358                         error = EINVAL;
 359                         break;
 360                 }
 361                 while (entry != &map->header &&
 362                     (entry->eflags & MAP_ENTRY_IS_SUB_MAP) != 0) {
 363                         entry = entry->next;
 364                         index++;
 365                 }
 366                 if (entry == &map->header) {
 367                         error = ENOENT;
 368                         break;
 369                 }
 370
 371                 /* We got an entry. */
 372                 pve->pve_entry = index + 1;
 373                 pve->pve_timestamp = map->timestamp;
 374                 pve->pve_start = entry->start;
 375                 pve->pve_end = entry->end - 1;
 376                 pve->pve_offset = entry->offset;
 377                 pve->pve_prot = entry->protection;
 378
 379                 /* Backing object's path needed? */
 380                 if (pve->pve_pathlen == 0)
 381                         break;
 382
 383                 pathlen = pve->pve_pathlen;
 384                 pve->pve_pathlen = 0;
 385
 386                 obj = entry->object.vm_object;
 387                 if (obj != NULL)
 388                         VM_OBJECT_RLOCK(obj);
 389         } while (0);
 390
 391         vm_map_unlock_read(map);
 392
 393         pve->pve_fsid = VNOVAL;
 394         pve->pve_fileid = VNOVAL;
 395
 396         if (error == 0 && obj != NULL) {
 397                 lobj = obj;
 398                 for (tobj = obj; tobj != NULL; tobj = tobj->backing_object) {
 399                         if (tobj != obj)
 400                                 VM_OBJECT_RLOCK(tobj);
 401                         if (lobj != obj)
 402                                 VM_OBJECT_RUNLOCK(lobj);
 403                         lobj = tobj;
 404                         pve->pve_offset += tobj->backing_object_offset;
 405                 }
 406                 vp = vm_object_vnode(lobj);
 407                 if (vp != NULL)
 408                         vref(vp);
 409                 if (lobj != obj)
 410                         VM_OBJECT_RUNLOCK(lobj);
 411                 VM_OBJECT_RUNLOCK(obj);
 412
 413                 if (vp != NULL) {
 414                         freepath = NULL;
 415                         fullpath = NULL;
 416                         vn_fullpath(td, vp, &fullpath, &freepath);
 417                         vn_lock(vp, LK_SHARED | LK_RETRY);
 418                         if (VOP_GETATTR(vp, &vattr, td->td_ucred) == 0) {
 419                                 pve->pve_fileid = vattr.va_fileid;
 420                                 pve->pve_fsid = vattr.va_fsid;
 421                         }
 422                         vput(vp);
 423
 424                         if (fullpath != NULL) {
 425                                 pve->pve_pathlen = strlen(fullpath) + 1;
 426                                 if (pve->pve_pathlen <= pathlen) {
 427                                         error = copyout(fullpath, pve->pve_path,
 428                                             pve->pve_pathlen);
 429                                 } else
 430                                         error = ENAMETOOLONG;
 431                         }
 432                         if (freepath != NULL)
 433                                 free(freepath, M_TEMP);
 434                 }
 435         }
 436         vmspace_free(vm);
 437         if (error == 0)
 438                 CTR3(KTR_PTRACE, "PT_VM_ENTRY: pid %d, entry %d, start %p",
 439                     p->p_pid, pve->pve_entry, pve->pve_start);
 440
 441         return (error);
 442 }
 443
 444 #ifdef COMPAT_FREEBSD32
 445 static int
 446 ptrace_vm_entry32(struct thread *td, struct proc *p,
 447     struct ptrace_vm_entry32 *pve32)
 448 {
 449         struct ptrace_vm_entry pve;
 450         int error;
 451
 452         pve.pve_entry = pve32->pve_entry;
 453         pve.pve_pathlen = pve32->pve_pathlen;
 454         pve.pve_path = (void *)(uintptr_t)pve32->pve_path;
 455
 456         error = ptrace_vm_entry(td, p, &pve);
 457         if (error == 0) {
 458                 pve32->pve_entry = pve.pve_entry;
 459                 pve32->pve_timestamp = pve.pve_timestamp;
 460                 pve32->pve_start = pve.pve_start;
 461                 pve32->pve_end = pve.pve_end;
 462                 pve32->pve_offset = pve.pve_offset;
 463                 pve32->pve_prot = pve.pve_prot;
 464                 pve32->pve_fileid = pve.pve_fileid;
 465                 pve32->pve_fsid = pve.pve_fsid;
 466         }
 467
 468         pve32->pve_pathlen = pve.pve_pathlen;
 469         return (error);
 470 }
 471
 472 static void
 473 ptrace_lwpinfo_to32(const struct ptrace_lwpinfo *pl,
 474     struct ptrace_lwpinfo32 *pl32)
 475 {
 476
 477         bzero(pl32, sizeof(*pl32));
 478         pl32->pl_lwpid = pl->pl_lwpid;
 479         pl32->pl_event = pl->pl_event;
 480         pl32->pl_flags = pl->pl_flags;
 481         pl32->pl_sigmask = pl->pl_sigmask;
 482         pl32->pl_siglist = pl->pl_siglist;
 483         siginfo_to_siginfo32(&pl->pl_siginfo, &pl32->pl_siginfo);
 484         strcpy(pl32->pl_tdname, pl->pl_tdname);
 485         pl32->pl_child_pid = pl->pl_child_pid;
 486         pl32->pl_syscall_code = pl->pl_syscall_code;
 487         pl32->pl_syscall_narg = pl->pl_syscall_narg;
 488 }
 489 #endif /* COMPAT_FREEBSD32 */
 490
 491 /*
 492  * Process debugging system call.
 493  */
 494 #ifndef _SYS_SYSPROTO_H_
 495 struct ptrace_args {
 496         int     req;
 497         pid_t   pid;
 498         caddr_t addr;
 499         int     data;
 500 };
 501 #endif
 502
 503 #ifdef COMPAT_FREEBSD32
 504 /*
 505  * This CPP subterfuge is to try and reduce the number of ifdefs in
 506  * the body of the code.
 507  *   COPYIN(uap->addr, &r.reg, sizeof r.reg);
 508  * becomes either:
 509  *   copyin(uap->addr, &r.reg, sizeof r.reg);
 510  * or
 511  *   copyin(uap->addr, &r.reg32, sizeof r.reg32);
 512  * .. except this is done at runtime.
 513  */
 514 #define COPYIN(u, k, s)         wrap32 ? \
 515         copyin(u, k ## 32, s ## 32) : \
 516         copyin(u, k, s)
 517 #define COPYOUT(k, u, s)        wrap32 ? \
 518         copyout(k ## 32, u, s ## 32) : \
 519         copyout(k, u, s)
 520 #else
 521 #define COPYIN(u, k, s)         copyin(u, k, s)
 522 #define COPYOUT(k, u, s)        copyout(k, u, s)
 523 #endif
 524 int
 525 sys_ptrace(struct thread *td, struct ptrace_args *uap)
 526 {
 527         /*
 528          * XXX this obfuscation is to reduce stack usage, but the register
 529          * structs may be too large to put on the stack anyway.
 530          */
 531         union {
 532                 struct ptrace_io_desc piod;
 533                 struct ptrace_lwpinfo pl;
 534                 struct ptrace_vm_entry pve;
 535                 struct dbreg dbreg;
 536                 struct fpreg fpreg;
 537                 struct reg reg;
 538 #ifdef COMPAT_FREEBSD32
 539                 struct dbreg32 dbreg32;
 540                 struct fpreg32 fpreg32;
 541                 struct reg32 reg32;
 542                 struct ptrace_io_desc32 piod32;
 543                 struct ptrace_lwpinfo32 pl32;
 544                 struct ptrace_vm_entry32 pve32;
 545 #endif
 546                 int ptevents;
 547         } r;
 548         void *addr;
 549         int error = 0;
 550 #ifdef COMPAT_FREEBSD32
 551         int wrap32 = 0;
 552
 553         if (SV_CURPROC_FLAG(SV_ILP32))
 554                 wrap32 = 1;
 555 #endif
 556         AUDIT_ARG_PID(uap->pid);
 557         AUDIT_ARG_CMD(uap->req);
 558         AUDIT_ARG_VALUE(uap->data);
 559         addr = &r;
 560         switch (uap->req) {
 561         case PT_GET_EVENT_MASK:
 562         case PT_GETREGS:
 563         case PT_GETFPREGS:
 564         case PT_GETDBREGS:
 565         case PT_LWPINFO:
 566                 break;
 567         case PT_SETREGS:
 568                 error = COPYIN(uap->addr, &r.reg, sizeof r.reg);
 569                 break;
 570         case PT_SETFPREGS:
 571                 error = COPYIN(uap->addr, &r.fpreg, sizeof r.fpreg);
 572                 break;
 573         case PT_SETDBREGS:
 574                 error = COPYIN(uap->addr, &r.dbreg, sizeof r.dbreg);
 575                 break;
 576         case PT_SET_EVENT_MASK:
 577                 if (uap->data != sizeof(r.ptevents))
 578                         error = EINVAL;
 579                 else
 580                         error = copyin(uap->addr, &r.ptevents, uap->data);
 581                 break;
 582         case PT_IO:
 583                 error = COPYIN(uap->addr, &r.piod, sizeof r.piod);
 584                 break;
 585         case PT_VM_ENTRY:
 586                 error = COPYIN(uap->addr, &r.pve, sizeof r.pve);
 587                 break;
 588         default:
 589                 addr = uap->addr;
 590                 break;
 591         }
 592         if (error)
 593                 return (error);
 594
 595         error = kern_ptrace(td, uap->req, uap->pid, addr, uap->data);
 596         if (error)
 597                 return (error);
 598
 599         switch (uap->req) {
 600         case PT_VM_ENTRY:
 601                 error = COPYOUT(&r.pve, uap->addr, sizeof r.pve);
 602                 break;
 603         case PT_IO:
 604                 error = COPYOUT(&r.piod, uap->addr, sizeof r.piod);
 605                 break;
 606         case PT_GETREGS:
 607                 error = COPYOUT(&r.reg, uap->addr, sizeof r.reg);
 608                 break;
 609         case PT_GETFPREGS:
 610                 error = COPYOUT(&r.fpreg, uap->addr, sizeof r.fpreg);
 611                 break;
 612         case PT_GETDBREGS:
 613                 error = COPYOUT(&r.dbreg, uap->addr, sizeof r.dbreg);
 614                 break;
 615         case PT_GET_EVENT_MASK:
 616                 /* NB: The size in uap->data is validated in kern_ptrace(). */
 617                 error = copyout(&r.ptevents, uap->addr, uap->data);
 618                 break;
 619         case PT_LWPINFO:
 620                 /* NB: The size in uap->data is validated in kern_ptrace(). */
 621                 error = copyout(&r.pl, uap->addr, uap->data);
 622                 break;
 623         }
 624
 625         return (error);
 626 }
 627 #undef COPYIN
 628 #undef COPYOUT
 629
 630 #ifdef COMPAT_FREEBSD32
 631 /*
 632  *   PROC_READ(regs, td2, addr);
 633  * becomes either:
 634  *   proc_read_regs(td2, addr);
 635  * or
 636  *   proc_read_regs32(td2, addr);
 637  * .. except this is done at runtime.  There is an additional
 638  * complication in that PROC_WRITE disallows 32 bit consumers
 639  * from writing to 64 bit address space targets.
 640  */
 641 #define PROC_READ(w, t, a)      wrap32 ? \
 642         proc_read_ ## w ## 32(t, a) : \
 643         proc_read_ ## w (t, a)
 644 #define PROC_WRITE(w, t, a)     wrap32 ? \
 645         (safe ? proc_write_ ## w ## 32(t, a) : EINVAL ) : \
 646         proc_write_ ## w (t, a)
 647 #else
 648 #define PROC_READ(w, t, a)      proc_read_ ## w (t, a)
 649 #define PROC_WRITE(w, t, a)     proc_write_ ## w (t, a)
 650 #endif
 651
 652 void
 653 proc_set_traced(struct proc *p, bool stop)
 654 {
 655
 656         PROC_LOCK_ASSERT(p, MA_OWNED);
 657         p->p_flag |= P_TRACED;
 658         if (stop)
 659                 p->p_flag2 |= P2_PTRACE_FSTP;
 660         p->p_ptevents = PTRACE_DEFAULT;
 661         p->p_oppid = p->p_pptr->p_pid;
 662 }
 663
 664 int
 665 kern_ptrace(struct thread *td, int req, pid_t pid, void *addr, int data)
 666 {
 667         struct iovec iov;
 668         struct uio uio;
 669         struct proc *curp, *p, *pp;
 670         struct thread *td2 = NULL, *td3;
 671         struct ptrace_io_desc *piod = NULL;
 672         struct ptrace_lwpinfo *pl;
 673         int error, write, tmp, num;
 674         int proctree_locked = 0;
 675         lwpid_t tid = 0, *buf;
 676 #ifdef COMPAT_FREEBSD32
 677         int wrap32 = 0, safe = 0;
 678         struct ptrace_io_desc32 *piod32 = NULL;
 679         struct ptrace_lwpinfo32 *pl32 = NULL;
 680         struct ptrace_lwpinfo plr;
 681 #endif
 682
 683         curp = td->td_proc;
 684
 685         /* Lock proctree before locking the process. */
 686         switch (req) {
 687         case PT_TRACE_ME:
 688         case PT_ATTACH:
 689         case PT_STEP:
 690         case PT_CONTINUE:
 691         case PT_TO_SCE:
 692         case PT_TO_SCX:
 693         case PT_SYSCALL:
 694         case PT_FOLLOW_FORK:
 695         case PT_LWP_EVENTS:
 696         case PT_GET_EVENT_MASK:
 697         case PT_SET_EVENT_MASK:
 698         case PT_DETACH:
 699                 sx_xlock(&proctree_lock);
 700                 proctree_locked = 1;
 701                 break;
 702         default:
 703                 break;
 704         }
 705
 706         write = 0;
 707         if (req == PT_TRACE_ME) {
 708                 p = td->td_proc;
 709                 PROC_LOCK(p);
 710         } else {
 711                 if (pid <= PID_MAX) {
 712                         if ((p = pfind(pid)) == NULL) {
 713                                 if (proctree_locked)
 714                                         sx_xunlock(&proctree_lock);
 715                                 return (ESRCH);
 716                         }
 717                 } else {
 718                         td2 = tdfind(pid, -1);
 719                         if (td2 == NULL) {
 720                                 if (proctree_locked)
 721                                         sx_xunlock(&proctree_lock);
 722                                 return (ESRCH);
 723                         }
 724                         p = td2->td_proc;
 725                         tid = pid;
 726                         pid = p->p_pid;
 727                 }
 728         }
 729         AUDIT_ARG_PROCESS(p);
 730
 731         if ((p->p_flag & P_WEXIT) != 0) {
 732                 error = ESRCH;
 733                 goto fail;
 734         }
 735         if ((error = p_cansee(td, p)) != 0)
 736                 goto fail;
 737
 738         if ((error = p_candebug(td, p)) != 0)
 739                 goto fail;
 740
 741         /*
 742          * System processes can't be debugged.
 743          */
 744         if ((p->p_flag & P_SYSTEM) != 0) {
 745                 error = EINVAL;
 746                 goto fail;
 747         }
 748
 749         if (tid == 0) {
 750                 if ((p->p_flag & P_STOPPED_TRACE) != 0) {
 751                         KASSERT(p->p_xthread != NULL, ("NULL p_xthread"));
 752                         td2 = p->p_xthread;
 753                 } else {
 754                         td2 = FIRST_THREAD_IN_PROC(p);
 755                 }
 756                 tid = td2->td_tid;
 757         }
 758
 759 #ifdef COMPAT_FREEBSD32
 760         /*
 761          * Test if we're a 32 bit client and what the target is.
 762          * Set the wrap controls accordingly.
 763          */
 764         if (SV_CURPROC_FLAG(SV_ILP32)) {
 765                 if (SV_PROC_FLAG(td2->td_proc, SV_ILP32))
 766                         safe = 1;
 767                 wrap32 = 1;
 768         }
 769 #endif
 770         /*
 771          * Permissions check
 772          */
 773         switch (req) {
 774         case PT_TRACE_ME:
 775                 /*
 776                  * Always legal, when there is a parent process which
 777                  * could trace us.  Otherwise, reject.
 778                  */
 779                 if ((p->p_flag & P_TRACED) != 0) {
 780                         error = EBUSY;
 781                         goto fail;
 782                 }
 783                 if (p->p_pptr == initproc) {
 784                         error = EPERM;
 785                         goto fail;
 786                 }
 787                 break;
 788
 789         case PT_ATTACH:
 790                 /* Self */
 791                 if (p == td->td_proc) {
 792                         error = EINVAL;
 793                         goto fail;
 794                 }
 795
 796                 /* Already traced */
 797                 if (p->p_flag & P_TRACED) {
 798                         error = EBUSY;
 799                         goto fail;
 800                 }
 801
 802                 /* Can't trace an ancestor if you're being traced. */
 803                 if (curp->p_flag & P_TRACED) {
 804                         for (pp = curp->p_pptr; pp != NULL; pp = pp->p_pptr) {
 805                                 if (pp == p) {
 806                                         error = EINVAL;
 807                                         goto fail;
 808                                 }
 809                         }
 810                 }
 811
 812
 813                 /* OK */
 814                 break;
 815
 816         case PT_CLEARSTEP:
 817                 /* Allow thread to clear single step for itself */
 818                 if (td->td_tid == tid)
 819                         break;
 820
 821                 /* FALLTHROUGH */
 822         default:
 823                 /* not being traced... */
 824                 if ((p->p_flag & P_TRACED) == 0) {
 825                         error = EPERM;
 826                         goto fail;
 827                 }
 828
 829                 /* not being traced by YOU */
 830                 if (p->p_pptr != td->td_proc) {
 831                         error = EBUSY;
 832                         goto fail;
 833                 }
 834
 835                 /* not currently stopped */
 836                 if ((p->p_flag & (P_STOPPED_SIG | P_STOPPED_TRACE)) == 0 ||
 837                     p->p_suspcount != p->p_numthreads  ||
 838                     (p->p_flag & P_WAITED) == 0) {
 839                         error = EBUSY;
 840                         goto fail;
 841                 }
 842
 843                 if ((p->p_flag & P_STOPPED_TRACE) == 0) {
 844                         static int count = 0;
 845                         if (count++ == 0)
 846                                 printf("P_STOPPED_TRACE not set.\n");
 847                 }
 848
 849                 /* OK */
 850                 break;
 851         }
 852
 853         /* Keep this process around until we finish this request. */
 854         _PHOLD(p);
 855
 856 #ifdef FIX_SSTEP
 857         /*
 858          * Single step fixup ala procfs
 859          */
 860         FIX_SSTEP(td2);
 861 #endif
 862
 863         /*
 864          * Actually do the requests
 865          */
 866
 867         td->td_retval[0] = 0;
 868
 869         switch (req) {
 870         case PT_TRACE_ME:
 871                 /* set my trace flag and "owner" so it can read/write me */
 872                 proc_set_traced(p, false);
 873                 if (p->p_flag & P_PPWAIT)
 874                         p->p_flag |= P_PPTRACE;
 875                 CTR1(KTR_PTRACE, "PT_TRACE_ME: pid %d", p->p_pid);
 876                 break;
 877
 878         case PT_ATTACH:
 879                 /* security check done above */
 880                 /*
 881                  * It would be nice if the tracing relationship was separate
 882                  * from the parent relationship but that would require
 883                  * another set of links in the proc struct or for "wait"
 884                  * to scan the entire proc table.  To make life easier,
 885                  * we just re-parent the process we're trying to trace.
 886                  * The old parent is remembered so we can put things back
 887                  * on a "detach".
 888                  */
 889                 proc_set_traced(p, true);
 890                 if (p->p_pptr != td->td_proc) {
 891                         proc_reparent(p, td->td_proc);
 892                 }
 893                 data = SIGSTOP;
 894                 CTR2(KTR_PTRACE, "PT_ATTACH: pid %d, oppid %d", p->p_pid,
 895                     p->p_oppid);
 896                 goto sendsig;   /* in PT_CONTINUE below */
 897
 898         case PT_CLEARSTEP:
 899                 CTR2(KTR_PTRACE, "PT_CLEARSTEP: tid %d (pid %d)", td2->td_tid,
 900                     p->p_pid);
 901                 error = ptrace_clear_single_step(td2);
 902                 break;
 903
 904         case PT_SETSTEP:
 905                 CTR2(KTR_PTRACE, "PT_SETSTEP: tid %d (pid %d)", td2->td_tid,
 906                     p->p_pid);
 907                 error = ptrace_single_step(td2);
 908                 break;
 909
 910         case PT_SUSPEND:
 911                 CTR2(KTR_PTRACE, "PT_SUSPEND: tid %d (pid %d)", td2->td_tid,
 912                     p->p_pid);
 913                 td2->td_dbgflags |= TDB_SUSPEND;
 914                 thread_lock(td2);
 915                 td2->td_flags |= TDF_NEEDSUSPCHK;
 916                 thread_unlock(td2);
 917                 break;
 918
 919         case PT_RESUME:
 920                 CTR2(KTR_PTRACE, "PT_RESUME: tid %d (pid %d)", td2->td_tid,
 921                     p->p_pid);
 922                 td2->td_dbgflags &= ~TDB_SUSPEND;
 923                 break;
 924
 925         case PT_FOLLOW_FORK:
 926                 CTR3(KTR_PTRACE, "PT_FOLLOW_FORK: pid %d %s -> %s", p->p_pid,
 927                     p->p_ptevents & PTRACE_FORK ? "enabled" : "disabled",
 928                     data ? "enabled" : "disabled");
 929                 if (data)
 930                         p->p_ptevents |= PTRACE_FORK;
 931                 else
 932                         p->p_ptevents &= ~PTRACE_FORK;
 933                 break;
 934
 935         case PT_LWP_EVENTS:
 936                 CTR3(KTR_PTRACE, "PT_LWP_EVENTS: pid %d %s -> %s", p->p_pid,
 937                     p->p_ptevents & PTRACE_LWP ? "enabled" : "disabled",
 938                     data ? "enabled" : "disabled");
 939                 if (data)
 940                         p->p_ptevents |= PTRACE_LWP;
 941                 else
 942                         p->p_ptevents &= ~PTRACE_LWP;
 943                 break;
 944
 945         case PT_GET_EVENT_MASK:
 946                 if (data != sizeof(p->p_ptevents)) {
 947                         error = EINVAL;
 948                         break;
 949                 }
 950                 CTR2(KTR_PTRACE, "PT_GET_EVENT_MASK: pid %d mask %#x", p->p_pid,
 951                     p->p_ptevents);
 952                 *(int *)addr = p->p_ptevents;
 953                 break;
 954
 955         case PT_SET_EVENT_MASK:
 956                 if (data != sizeof(p->p_ptevents)) {
 957                         error = EINVAL;
 958                         break;
 959                 }
 960                 tmp = *(int *)addr;
 961                 if ((tmp & ~(PTRACE_EXEC | PTRACE_SCE | PTRACE_SCX |
 962                     PTRACE_FORK | PTRACE_LWP | PTRACE_VFORK)) != 0) {
 963                         error = EINVAL;
 964                         break;
 965                 }
 966                 CTR3(KTR_PTRACE, "PT_SET_EVENT_MASK: pid %d mask %#x -> %#x",
 967                     p->p_pid, p->p_ptevents, tmp);
 968                 p->p_ptevents = tmp;
 969                 break;
 970
 971         case PT_STEP:
 972         case PT_CONTINUE:
 973         case PT_TO_SCE:
 974         case PT_TO_SCX:
 975         case PT_SYSCALL:
 976         case PT_DETACH:
 977                 /* Zero means do not send any signal */
 978                 if (data < 0 || data > _SIG_MAXSIG) {
 979                         error = EINVAL;
 980                         break;
 981                 }
 982
 983                 switch (req) {
 984                 case PT_STEP:
 985                         CTR3(KTR_PTRACE, "PT_STEP: tid %d (pid %d), sig = %d",
 986                             td2->td_tid, p->p_pid, data);
 987                         error = ptrace_single_step(td2);
 988                         if (error)
 989                                 goto out;
 990                         break;
 991                 case PT_CONTINUE:
 992                 case PT_TO_SCE:
 993                 case PT_TO_SCX:
 994                 case PT_SYSCALL:
 995                         if (addr != (void *)1) {
 996                                 error = ptrace_set_pc(td2,
 997                                     (u_long)(uintfptr_t)addr);
 998                                 if (error)
 999                                         goto out;
1000                         }
1001                         switch (req) {
1002                         case PT_TO_SCE:
1003                                 p->p_ptevents |= PTRACE_SCE;
1004                                 CTR4(KTR_PTRACE,
1005                     "PT_TO_SCE: pid %d, events = %#x, PC = %#lx, sig = %d",
1006                                     p->p_pid, p->p_ptevents,
1007                                     (u_long)(uintfptr_t)addr, data);
1008                                 break;
1009                         case PT_TO_SCX:
1010                                 p->p_ptevents |= PTRACE_SCX;
1011                                 CTR4(KTR_PTRACE,
1012                     "PT_TO_SCX: pid %d, events = %#x, PC = %#lx, sig = %d",
1013                                     p->p_pid, p->p_ptevents,
1014                                     (u_long)(uintfptr_t)addr, data);
1015                                 break;
1016                         case PT_SYSCALL:
1017                                 p->p_ptevents |= PTRACE_SYSCALL;
1018                                 CTR4(KTR_PTRACE,
1019                     "PT_SYSCALL: pid %d, events = %#x, PC = %#lx, sig = %d",
1020                                     p->p_pid, p->p_ptevents,
1021                                     (u_long)(uintfptr_t)addr, data);
1022                                 break;
1023                         case PT_CONTINUE:
1024                                 CTR3(KTR_PTRACE,
1025                                     "PT_CONTINUE: pid %d, PC = %#lx, sig = %d",
1026                                     p->p_pid, (u_long)(uintfptr_t)addr, data);
1027                                 break;
1028                         }
1029                         break;
1030                 case PT_DETACH:
1031                         /*
1032                          * Reset the process parent.
1033                          *
1034                          * NB: This clears P_TRACED before reparenting
1035                          * a detached process back to its original
1036                          * parent.  Otherwise the debugee will be set
1037                          * as an orphan of the debugger.
1038                          */
1039                         p->p_flag &= ~(P_TRACED | P_WAITED);
1040                         if (p->p_oppid != p->p_pptr->p_pid) {
1041                                 PROC_LOCK(p->p_pptr);
1042                                 sigqueue_take(p->p_ksi);
1043                                 PROC_UNLOCK(p->p_pptr);
1044
1045                                 pp = proc_realparent(p);
1046                                 proc_reparent(p, pp);
1047                                 if (pp == initproc)
1048                                         p->p_sigparent = SIGCHLD;
1049                                 CTR3(KTR_PTRACE,
1050                             "PT_DETACH: pid %d reparented to pid %d, sig %d",
1051                                     p->p_pid, pp->p_pid, data);
1052                         } else
1053                                 CTR2(KTR_PTRACE, "PT_DETACH: pid %d, sig %d",
1054                                     p->p_pid, data);
1055                         p->p_oppid = 0;
1056                         p->p_ptevents = 0;
1057                         FOREACH_THREAD_IN_PROC(p, td3) {
1058                                 if ((td3->td_dbgflags & TDB_FSTP) != 0) {
1059                                         sigqueue_delete(&td3->td_sigqueue,
1060                                             SIGSTOP);
1061                                 }
1062                                 td3->td_dbgflags &= ~(TDB_XSIG | TDB_FSTP);
1063                         }
1064                         if ((p->p_flag2 & P2_PTRACE_FSTP) != 0) {
1065                                 sigqueue_delete(&p->p_sigqueue, SIGSTOP);
1066                                 p->p_flag2 &= ~P2_PTRACE_FSTP;
1067                         }
1068
1069                         /* should we send SIGCHLD? */
1070                         /* childproc_continued(p); */
1071                         break;
1072                 }
1073
1074         sendsig:
1075                 /*
1076                  * Clear the pending event for the thread that just
1077                  * reported its event (p_xthread).  This may not be
1078                  * the thread passed to PT_CONTINUE, PT_STEP, etc. if
1079                  * the debugger is resuming a different thread.
1080                  */
1081                 td2 = p->p_xthread;
1082                 if (proctree_locked) {
1083                         sx_xunlock(&proctree_lock);
1084                         proctree_locked = 0;
1085                 }
1086                 p->p_xstat = data;
1087                 p->p_xthread = NULL;
1088                 if ((p->p_flag & (P_STOPPED_SIG | P_STOPPED_TRACE)) != 0) {
1089                         /* deliver or queue signal */
1090                         td2->td_dbgflags &= ~TDB_XSIG;
1091                         td2->td_xsig = data;
1092
1093                         /*
1094                          * P_WKILLED is insurance that a PT_KILL/SIGKILL always
1095                          * works immediately, even if another thread is
1096                          * unsuspended first and attempts to handle a different
1097                          * signal or if the POSIX.1b style signal queue cannot
1098                          * accommodate any new signals.
1099                          */
1100                         if (data == SIGKILL)
1101                                 p->p_flag |= P_WKILLED;
1102
1103                         if (req == PT_DETACH) {
1104                                 FOREACH_THREAD_IN_PROC(p, td3)
1105                                         td3->td_dbgflags &= ~TDB_SUSPEND;
1106                         }
1107                         /*
1108                          * unsuspend all threads, to not let a thread run,
1109                          * you should use PT_SUSPEND to suspend it before
1110                          * continuing process.
1111                          */
1112                         PROC_SLOCK(p);
1113                         p->p_flag &= ~(P_STOPPED_TRACE|P_STOPPED_SIG|P_WAITED);
1114                         thread_unsuspend(p);
1115                         PROC_SUNLOCK(p);
1116                         if (req == PT_ATTACH)
1117                                 kern_psignal(p, data);
1118                 } else {
1119                         if (data)
1120                                 kern_psignal(p, data);
1121                 }
1122                 break;
1123
1124         case PT_WRITE_I:
1125         case PT_WRITE_D:
1126                 td2->td_dbgflags |= TDB_USERWR;
1127                 write = 1;
1128                 /* FALLTHROUGH */
1129         case PT_READ_I:
1130         case PT_READ_D:
1131                 PROC_UNLOCK(p);
1132                 tmp = 0;
1133                 /* write = 0 set above */
1134                 iov.iov_base = write ? (caddr_t)&data : (caddr_t)&tmp;
1135                 iov.iov_len = sizeof(int);
1136                 uio.uio_iov = &iov;
1137                 uio.uio_iovcnt = 1;
1138                 uio.uio_offset = (off_t)(uintptr_t)addr;
1139                 uio.uio_resid = sizeof(int);
1140                 uio.uio_segflg = UIO_SYSSPACE;  /* i.e.: the uap */
1141                 uio.uio_rw = write ? UIO_WRITE : UIO_READ;
1142                 uio.uio_td = td;
1143                 error = proc_rwmem(p, &uio);
1144                 if (uio.uio_resid != 0) {
1145                         /*
1146                          * XXX proc_rwmem() doesn't currently return ENOSPC,
1147                          * so I think write() can bogusly return 0.
1148                          * XXX what happens for short writes?  We don't want
1149                          * to write partial data.
1150                          * XXX proc_rwmem() returns EPERM for other invalid
1151                          * addresses.  Convert this to EINVAL.  Does this
1152                          * clobber returns of EPERM for other reasons?
1153                          */
1154                         if (error == 0 || error == ENOSPC || error == EPERM)
1155                                 error = EINVAL; /* EOF */
1156                 }
1157                 if (!write)
1158                         td->td_retval[0] = tmp;
1159                 if (error == 0) {
1160                         if (write)
1161                                 CTR3(KTR_PTRACE, "PT_WRITE: pid %d: %p <= %#x",
1162                                     p->p_pid, addr, data);
1163                         else
1164                                 CTR3(KTR_PTRACE, "PT_READ: pid %d: %p >= %#x",
1165                                     p->p_pid, addr, tmp);
1166                 }
1167                 PROC_LOCK(p);
1168                 break;
1169
1170         case PT_IO:
1171 #ifdef COMPAT_FREEBSD32
1172                 if (wrap32) {
1173                         piod32 = addr;
1174                         iov.iov_base = (void *)(uintptr_t)piod32->piod_addr;
1175                         iov.iov_len = piod32->piod_len;
1176                         uio.uio_offset = (off_t)(uintptr_t)piod32->piod_offs;
1177                         uio.uio_resid = piod32->piod_len;
1178                 } else
1179 #endif
1180                 {
1181                         piod = addr;
1182                         iov.iov_base = piod->piod_addr;
1183                         iov.iov_len = piod->piod_len;
1184                         uio.uio_offset = (off_t)(uintptr_t)piod->piod_offs;
1185                         uio.uio_resid = piod->piod_len;
1186                 }
1187                 uio.uio_iov = &iov;
1188                 uio.uio_iovcnt = 1;
1189                 uio.uio_segflg = UIO_USERSPACE;
1190                 uio.uio_td = td;
1191 #ifdef COMPAT_FREEBSD32
1192                 tmp = wrap32 ? piod32->piod_op : piod->piod_op;
1193 #else
1194                 tmp = piod->piod_op;
1195 #endif
1196                 switch (tmp) {
1197                 case PIOD_READ_D:
1198                 case PIOD_READ_I:
1199                         CTR3(KTR_PTRACE, "PT_IO: pid %d: READ (%p, %#x)",
1200                             p->p_pid, (uintptr_t)uio.uio_offset, uio.uio_resid);
1201                         uio.uio_rw = UIO_READ;
1202                         break;
1203                 case PIOD_WRITE_D:
1204                 case PIOD_WRITE_I:
1205                         CTR3(KTR_PTRACE, "PT_IO: pid %d: WRITE (%p, %#x)",
1206                             p->p_pid, (uintptr_t)uio.uio_offset, uio.uio_resid);
1207                         td2->td_dbgflags |= TDB_USERWR;
1208                         uio.uio_rw = UIO_WRITE;
1209                         break;
1210                 default:
1211                         error = EINVAL;
1212                         goto out;
1213                 }
1214                 PROC_UNLOCK(p);
1215                 error = proc_rwmem(p, &uio);
1216 #ifdef COMPAT_FREEBSD32
1217                 if (wrap32)
1218                         piod32->piod_len -= uio.uio_resid;
1219                 else
1220 #endif
1221                         piod->piod_len -= uio.uio_resid;
1222                 PROC_LOCK(p);
1223                 break;
1224
1225         case PT_KILL:
1226                 CTR1(KTR_PTRACE, "PT_KILL: pid %d", p->p_pid);
1227                 data = SIGKILL;
1228                 goto sendsig;   /* in PT_CONTINUE above */
1229
1230         case PT_SETREGS:
1231                 CTR2(KTR_PTRACE, "PT_SETREGS: tid %d (pid %d)", td2->td_tid,
1232                     p->p_pid);
1233                 td2->td_dbgflags |= TDB_USERWR;
1234                 error = PROC_WRITE(regs, td2, addr);
1235                 break;
1236
1237         case PT_GETREGS:
1238                 CTR2(KTR_PTRACE, "PT_GETREGS: tid %d (pid %d)", td2->td_tid,
1239                     p->p_pid);
1240                 error = PROC_READ(regs, td2, addr);
1241                 break;
1242
1243         case PT_SETFPREGS:
1244                 CTR2(KTR_PTRACE, "PT_SETFPREGS: tid %d (pid %d)", td2->td_tid,
1245                     p->p_pid);
1246                 td2->td_dbgflags |= TDB_USERWR;
1247                 error = PROC_WRITE(fpregs, td2, addr);
1248                 break;
1249
1250         case PT_GETFPREGS:
1251                 CTR2(KTR_PTRACE, "PT_GETFPREGS: tid %d (pid %d)", td2->td_tid,
1252                     p->p_pid);
1253                 error = PROC_READ(fpregs, td2, addr);
1254                 break;
1255
1256         case PT_SETDBREGS:
1257                 CTR2(KTR_PTRACE, "PT_SETDBREGS: tid %d (pid %d)", td2->td_tid,
1258                     p->p_pid);
1259                 td2->td_dbgflags |= TDB_USERWR;
1260                 error = PROC_WRITE(dbregs, td2, addr);
1261                 break;
1262
1263         case PT_GETDBREGS:
1264                 CTR2(KTR_PTRACE, "PT_GETDBREGS: tid %d (pid %d)", td2->td_tid,
1265                     p->p_pid);
1266                 error = PROC_READ(dbregs, td2, addr);
1267                 break;
1268
1269         case PT_LWPINFO:
1270                 if (data <= 0 ||
1271 #ifdef COMPAT_FREEBSD32
1272                     (!wrap32 && data > sizeof(*pl)) ||
1273                     (wrap32 && data > sizeof(*pl32))) {
1274 #else
1275                     data > sizeof(*pl)) {
1276 #endif
1277                         error = EINVAL;
1278                         break;
1279                 }
1280 #ifdef COMPAT_FREEBSD32
1281                 if (wrap32) {
1282                         pl = &plr;
1283                         pl32 = addr;
1284                 } else
1285 #endif
1286                 pl = addr;
1287                 bzero(pl, sizeof(*pl));
1288                 pl->pl_lwpid = td2->td_tid;
1289                 pl->pl_event = PL_EVENT_NONE;
1290                 pl->pl_flags = 0;
1291                 if (td2->td_dbgflags & TDB_XSIG) {
1292                         pl->pl_event = PL_EVENT_SIGNAL;
1293                         if (td2->td_dbgksi.ksi_signo != 0 &&
1294 #ifdef COMPAT_FREEBSD32
1295                             ((!wrap32 && data >= offsetof(struct ptrace_lwpinfo,
1296                             pl_siginfo) + sizeof(pl->pl_siginfo)) ||
1297                             (wrap32 && data >= offsetof(struct ptrace_lwpinfo32,
1298                             pl_siginfo) + sizeof(struct siginfo32)))
1299 #else
1300                             data >= offsetof(struct ptrace_lwpinfo, pl_siginfo)
1301                             + sizeof(pl->pl_siginfo)
1302 #endif
1303                         ){
1304                                 pl->pl_flags |= PL_FLAG_SI;
1305                                 pl->pl_siginfo = td2->td_dbgksi.ksi_info;
1306                         }
1307                 }
1308                 if (td2->td_dbgflags & TDB_SCE)
1309                         pl->pl_flags |= PL_FLAG_SCE;
1310                 else if (td2->td_dbgflags & TDB_SCX)
1311                         pl->pl_flags |= PL_FLAG_SCX;
1312                 if (td2->td_dbgflags & TDB_EXEC)
1313                         pl->pl_flags |= PL_FLAG_EXEC;
1314                 if (td2->td_dbgflags & TDB_FORK) {
1315                         pl->pl_flags |= PL_FLAG_FORKED;
1316                         pl->pl_child_pid = td2->td_dbg_forked;
1317                         if (td2->td_dbgflags & TDB_VFORK)
1318                                 pl->pl_flags |= PL_FLAG_VFORKED;
1319                 } else if ((td2->td_dbgflags & (TDB_SCX | TDB_VFORK)) ==
1320                     TDB_VFORK)
1321                         pl->pl_flags |= PL_FLAG_VFORK_DONE;
1322                 if (td2->td_dbgflags & TDB_CHILD)
1323                         pl->pl_flags |= PL_FLAG_CHILD;
1324                 if (td2->td_dbgflags & TDB_BORN)
1325                         pl->pl_flags |= PL_FLAG_BORN;
1326                 if (td2->td_dbgflags & TDB_EXIT)
1327                         pl->pl_flags |= PL_FLAG_EXITED;
1328                 pl->pl_sigmask = td2->td_sigmask;
1329                 pl->pl_siglist = td2->td_siglist;
1330                 strcpy(pl->pl_tdname, td2->td_name);
1331                 if ((td2->td_dbgflags & (TDB_SCE | TDB_SCX)) != 0) {
1332                         pl->pl_syscall_code = td2->td_dbg_sc_code;
1333                         pl->pl_syscall_narg = td2->td_dbg_sc_narg;
1334                 } else {
1335                         pl->pl_syscall_code = 0;
1336                         pl->pl_syscall_narg = 0;
1337                 }
1338 #ifdef COMPAT_FREEBSD32
1339                 if (wrap32)
1340                         ptrace_lwpinfo_to32(pl, pl32);
1341 #endif
1342                 CTR6(KTR_PTRACE,
1343     "PT_LWPINFO: tid %d (pid %d) event %d flags %#x child pid %d syscall %d",
1344                     td2->td_tid, p->p_pid, pl->pl_event, pl->pl_flags,
1345                     pl->pl_child_pid, pl->pl_syscall_code);
1346                 break;
1347
1348         case PT_GETNUMLWPS:
1349                 CTR2(KTR_PTRACE, "PT_GETNUMLWPS: pid %d: %d threads", p->p_pid,
1350                     p->p_numthreads);
1351                 td->td_retval[0] = p->p_numthreads;
1352                 break;
1353
1354         case PT_GETLWPLIST:
1355                 CTR3(KTR_PTRACE, "PT_GETLWPLIST: pid %d: data %d, actual %d",
1356                     p->p_pid, data, p->p_numthreads);
1357                 if (data <= 0) {
1358                         error = EINVAL;
1359                         break;
1360                 }
1361                 num = imin(p->p_numthreads, data);
1362                 PROC_UNLOCK(p);
1363                 buf = malloc(num * sizeof(lwpid_t), M_TEMP, M_WAITOK);
1364                 tmp = 0;
1365                 PROC_LOCK(p);
1366                 FOREACH_THREAD_IN_PROC(p, td2) {
1367                         if (tmp >= num)
1368                                 break;
1369                         buf[tmp++] = td2->td_tid;
1370                 }
1371                 PROC_UNLOCK(p);
1372                 error = copyout(buf, addr, tmp * sizeof(lwpid_t));
1373                 free(buf, M_TEMP);
1374                 if (!error)
1375                         td->td_retval[0] = tmp;
1376                 PROC_LOCK(p);
1377                 break;
1378
1379         case PT_VM_TIMESTAMP:
1380                 CTR2(KTR_PTRACE, "PT_VM_TIMESTAMP: pid %d: timestamp %d",
1381                     p->p_pid, p->p_vmspace->vm_map.timestamp);
1382                 td->td_retval[0] = p->p_vmspace->vm_map.timestamp;
1383                 break;
1384
1385         case PT_VM_ENTRY:
1386                 PROC_UNLOCK(p);
1387 #ifdef COMPAT_FREEBSD32
1388                 if (wrap32)
1389                         error = ptrace_vm_entry32(td, p, addr);
1390                 else
1391 #endif
1392                 error = ptrace_vm_entry(td, p, addr);
1393                 PROC_LOCK(p);
1394                 break;
1395
1396         default:
1397 #ifdef __HAVE_PTRACE_MACHDEP
1398                 if (req >= PT_FIRSTMACH) {
1399                         PROC_UNLOCK(p);
1400                         error = cpu_ptrace(td2, req, addr, data);
1401                         PROC_LOCK(p);
1402                 } else
1403 #endif
1404                         /* Unknown request. */
1405                         error = EINVAL;
1406                 break;
1407         }
1408
1409 out:
1410         /* Drop our hold on this process now that the request has completed. */
1411         _PRELE(p);
1412 fail:
1413         PROC_UNLOCK(p);
1414         if (proctree_locked)
1415                 sx_xunlock(&proctree_lock);
1416         return (error);
1417 }
1418 #undef PROC_READ
1419 #undef PROC_WRITE
1420
1421 /*
1422  * Stop a process because of a debugging event;
1423  * stay stopped until p->p_step is cleared
1424  * (cleared by PIOCCONT in procfs).
1425  */
1426 void
1427 stopevent(struct proc *p, unsigned int event, unsigned int val)
1428 {
1429
1430         PROC_LOCK_ASSERT(p, MA_OWNED);
1431         p->p_step = 1;
1432         CTR3(KTR_PTRACE, "stopevent: pid %d event %u val %u", p->p_pid, event,
1433             val);
1434         do {
1435                 p->p_xstat = val;
1436                 p->p_xthread = NULL;
1437                 p->p_stype = event;     /* Which event caused the stop? */
1438                 wakeup(&p->p_stype);    /* Wake up any PIOCWAIT'ing procs */
1439                 msleep(&p->p_step, &p->p_mtx, PWAIT, "stopevent", 0);
1440         } while (p->p_step);
1441 }