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         pl32->pl_lwpid = pl->pl_lwpid;
 478         pl32->pl_event = pl->pl_event;
 479         pl32->pl_flags = pl->pl_flags;
 480         pl32->pl_sigmask = pl->pl_sigmask;
 481         pl32->pl_siglist = pl->pl_siglist;
 482         siginfo_to_siginfo32(&pl->pl_siginfo, &pl32->pl_siginfo);
 483         strcpy(pl32->pl_tdname, pl->pl_tdname);
 484         pl32->pl_child_pid = pl->pl_child_pid;
 485         pl32->pl_syscall_code = pl->pl_syscall_code;
 486         pl32->pl_syscall_narg = pl->pl_syscall_narg;
 487 }
 488 #endif /* COMPAT_FREEBSD32 */
 489
 490 /*
 491  * Process debugging system call.
 492  */
 493 #ifndef _SYS_SYSPROTO_H_
 494 struct ptrace_args {
 495         int     req;
 496         pid_t   pid;
 497         caddr_t addr;
 498         int     data;
 499 };
 500 #endif
 501
 502 #ifdef COMPAT_FREEBSD32
 503 /*
 504  * This CPP subterfuge is to try and reduce the number of ifdefs in
 505  * the body of the code.
 506  *   COPYIN(uap->addr, &r.reg, sizeof r.reg);
 507  * becomes either:
 508  *   copyin(uap->addr, &r.reg, sizeof r.reg);
 509  * or
 510  *   copyin(uap->addr, &r.reg32, sizeof r.reg32);
 511  * .. except this is done at runtime.
 512  */
 513 #define COPYIN(u, k, s)         wrap32 ? \
 514         copyin(u, k ## 32, s ## 32) : \
 515         copyin(u, k, s)
 516 #define COPYOUT(k, u, s)        wrap32 ? \
 517         copyout(k ## 32, u, s ## 32) : \
 518         copyout(k, u, s)
 519 #else
 520 #define COPYIN(u, k, s)         copyin(u, k, s)
 521 #define COPYOUT(k, u, s)        copyout(k, u, s)
 522 #endif
 523 int
 524 sys_ptrace(struct thread *td, struct ptrace_args *uap)
 525 {
 526         /*
 527          * XXX this obfuscation is to reduce stack usage, but the register
 528          * structs may be too large to put on the stack anyway.
 529          */
 530         union {
 531                 struct ptrace_io_desc piod;
 532                 struct ptrace_lwpinfo pl;
 533                 struct ptrace_vm_entry pve;
 534                 struct dbreg dbreg;
 535                 struct fpreg fpreg;
 536                 struct reg reg;
 537 #ifdef COMPAT_FREEBSD32
 538                 struct dbreg32 dbreg32;
 539                 struct fpreg32 fpreg32;
 540                 struct reg32 reg32;
 541                 struct ptrace_io_desc32 piod32;
 542                 struct ptrace_lwpinfo32 pl32;
 543                 struct ptrace_vm_entry32 pve32;
 544 #endif
 545                 int ptevents;
 546         } r;
 547         void *addr;
 548         int error = 0;
 549 #ifdef COMPAT_FREEBSD32
 550         int wrap32 = 0;
 551
 552         if (SV_CURPROC_FLAG(SV_ILP32))
 553                 wrap32 = 1;
 554 #endif
 555         AUDIT_ARG_PID(uap->pid);
 556         AUDIT_ARG_CMD(uap->req);
 557         AUDIT_ARG_VALUE(uap->data);
 558         addr = &r;
 559         switch (uap->req) {
 560         case PT_GET_EVENT_MASK:
 561         case PT_GETREGS:
 562         case PT_GETFPREGS:
 563         case PT_GETDBREGS:
 564         case PT_LWPINFO:
 565                 break;
 566         case PT_SETREGS:
 567                 error = COPYIN(uap->addr, &r.reg, sizeof r.reg);
 568                 break;
 569         case PT_SETFPREGS:
 570                 error = COPYIN(uap->addr, &r.fpreg, sizeof r.fpreg);
 571                 break;
 572         case PT_SETDBREGS:
 573                 error = COPYIN(uap->addr, &r.dbreg, sizeof r.dbreg);
 574                 break;
 575         case PT_SET_EVENT_MASK:
 576                 if (uap->data != sizeof(r.ptevents))
 577                         error = EINVAL;
 578                 else
 579                         error = copyin(uap->addr, &r.ptevents, uap->data);
 580                 break;
 581         case PT_IO:
 582                 error = COPYIN(uap->addr, &r.piod, sizeof r.piod);
 583                 break;
 584         case PT_VM_ENTRY:
 585                 error = COPYIN(uap->addr, &r.pve, sizeof r.pve);
 586                 break;
 587         default:
 588                 addr = uap->addr;
 589                 break;
 590         }
 591         if (error)
 592                 return (error);
 593
 594         error = kern_ptrace(td, uap->req, uap->pid, addr, uap->data);
 595         if (error)
 596                 return (error);
 597
 598         switch (uap->req) {
 599         case PT_VM_ENTRY:
 600                 error = COPYOUT(&r.pve, uap->addr, sizeof r.pve);
 601                 break;
 602         case PT_IO:
 603                 error = COPYOUT(&r.piod, uap->addr, sizeof r.piod);
 604                 break;
 605         case PT_GETREGS:
 606                 error = COPYOUT(&r.reg, uap->addr, sizeof r.reg);
 607                 break;
 608         case PT_GETFPREGS:
 609                 error = COPYOUT(&r.fpreg, uap->addr, sizeof r.fpreg);
 610                 break;
 611         case PT_GETDBREGS:
 612                 error = COPYOUT(&r.dbreg, uap->addr, sizeof r.dbreg);
 613                 break;
 614         case PT_GET_EVENT_MASK:
 615                 /* NB: The size in uap->data is validated in kern_ptrace(). */
 616                 error = copyout(&r.ptevents, uap->addr, uap->data);
 617                 break;
 618         case PT_LWPINFO:
 619                 /* NB: The size in uap->data is validated in kern_ptrace(). */
 620                 error = copyout(&r.pl, uap->addr, uap->data);
 621                 break;
 622         }
 623
 624         return (error);
 625 }
 626 #undef COPYIN
 627 #undef COPYOUT
 628
 629 #ifdef COMPAT_FREEBSD32
 630 /*
 631  *   PROC_READ(regs, td2, addr);
 632  * becomes either:
 633  *   proc_read_regs(td2, addr);
 634  * or
 635  *   proc_read_regs32(td2, addr);
 636  * .. except this is done at runtime.  There is an additional
 637  * complication in that PROC_WRITE disallows 32 bit consumers
 638  * from writing to 64 bit address space targets.
 639  */
 640 #define PROC_READ(w, t, a)      wrap32 ? \
 641         proc_read_ ## w ## 32(t, a) : \
 642         proc_read_ ## w (t, a)
 643 #define PROC_WRITE(w, t, a)     wrap32 ? \
 644         (safe ? proc_write_ ## w ## 32(t, a) : EINVAL ) : \
 645         proc_write_ ## w (t, a)
 646 #else
 647 #define PROC_READ(w, t, a)      proc_read_ ## w (t, a)
 648 #define PROC_WRITE(w, t, a)     proc_write_ ## w (t, a)
 649 #endif
 650
 651 void
 652 proc_set_traced(struct proc *p)
 653 {
 654
 655         PROC_LOCK_ASSERT(p, MA_OWNED);
 656         p->p_flag |= P_TRACED;
 657         p->p_flag2 |= P2_PTRACE_FSTP;
 658         p->p_ptevents = PTRACE_DEFAULT;
 659         p->p_oppid = p->p_pptr->p_pid;
 660 }
 661
 662 int
 663 kern_ptrace(struct thread *td, int req, pid_t pid, void *addr, int data)
 664 {
 665         struct iovec iov;
 666         struct uio uio;
 667         struct proc *curp, *p, *pp;
 668         struct thread *td2 = NULL, *td3;
 669         struct ptrace_io_desc *piod = NULL;
 670         struct ptrace_lwpinfo *pl;
 671         int error, write, tmp, num;
 672         int proctree_locked = 0;
 673         lwpid_t tid = 0, *buf;
 674 #ifdef COMPAT_FREEBSD32
 675         int wrap32 = 0, safe = 0;
 676         struct ptrace_io_desc32 *piod32 = NULL;
 677         struct ptrace_lwpinfo32 *pl32 = NULL;
 678         struct ptrace_lwpinfo plr;
 679 #endif
 680
 681         curp = td->td_proc;
 682
 683         /* Lock proctree before locking the process. */
 684         switch (req) {
 685         case PT_TRACE_ME:
 686         case PT_ATTACH:
 687         case PT_STEP:
 688         case PT_CONTINUE:
 689         case PT_TO_SCE:
 690         case PT_TO_SCX:
 691         case PT_SYSCALL:
 692         case PT_FOLLOW_FORK:
 693         case PT_LWP_EVENTS:
 694         case PT_GET_EVENT_MASK:
 695         case PT_SET_EVENT_MASK:
 696         case PT_DETACH:
 697                 sx_xlock(&proctree_lock);
 698                 proctree_locked = 1;
 699                 break;
 700         default:
 701                 break;
 702         }
 703
 704         write = 0;
 705         if (req == PT_TRACE_ME) {
 706                 p = td->td_proc;
 707                 PROC_LOCK(p);
 708         } else {
 709                 if (pid <= PID_MAX) {
 710                         if ((p = pfind(pid)) == NULL) {
 711                                 if (proctree_locked)
 712                                         sx_xunlock(&proctree_lock);
 713                                 return (ESRCH);
 714                         }
 715                 } else {
 716                         td2 = tdfind(pid, -1);
 717                         if (td2 == NULL) {
 718                                 if (proctree_locked)
 719                                         sx_xunlock(&proctree_lock);
 720                                 return (ESRCH);
 721                         }
 722                         p = td2->td_proc;
 723                         tid = pid;
 724                         pid = p->p_pid;
 725                 }
 726         }
 727         AUDIT_ARG_PROCESS(p);
 728
 729         if ((p->p_flag & P_WEXIT) != 0) {
 730                 error = ESRCH;
 731                 goto fail;
 732         }
 733         if ((error = p_cansee(td, p)) != 0)
 734                 goto fail;
 735
 736         if ((error = p_candebug(td, p)) != 0)
 737                 goto fail;
 738
 739         /*
 740          * System processes can't be debugged.
 741          */
 742         if ((p->p_flag & P_SYSTEM) != 0) {
 743                 error = EINVAL;
 744                 goto fail;
 745         }
 746
 747         if (tid == 0) {
 748                 if ((p->p_flag & P_STOPPED_TRACE) != 0) {
 749                         KASSERT(p->p_xthread != NULL, ("NULL p_xthread"));
 750                         td2 = p->p_xthread;
 751                 } else {
 752                         td2 = FIRST_THREAD_IN_PROC(p);
 753                 }
 754                 tid = td2->td_tid;
 755         }
 756
 757 #ifdef COMPAT_FREEBSD32
 758         /*
 759          * Test if we're a 32 bit client and what the target is.
 760          * Set the wrap controls accordingly.
 761          */
 762         if (SV_CURPROC_FLAG(SV_ILP32)) {
 763                 if (SV_PROC_FLAG(td2->td_proc, SV_ILP32))
 764                         safe = 1;
 765                 wrap32 = 1;
 766         }
 767 #endif
 768         /*
 769          * Permissions check
 770          */
 771         switch (req) {
 772         case PT_TRACE_ME:
 773                 /*
 774                  * Always legal, when there is a parent process which
 775                  * could trace us.  Otherwise, reject.
 776                  */
 777                 if ((p->p_flag & P_TRACED) != 0) {
 778                         error = EBUSY;
 779                         goto fail;
 780                 }
 781                 if (p->p_pptr == initproc) {
 782                         error = EPERM;
 783                         goto fail;
 784                 }
 785                 break;
 786
 787         case PT_ATTACH:
 788                 /* Self */
 789                 if (p == td->td_proc) {
 790                         error = EINVAL;
 791                         goto fail;
 792                 }
 793
 794                 /* Already traced */
 795                 if (p->p_flag & P_TRACED) {
 796                         error = EBUSY;
 797                         goto fail;
 798                 }
 799
 800                 /* Can't trace an ancestor if you're being traced. */
 801                 if (curp->p_flag & P_TRACED) {
 802                         for (pp = curp->p_pptr; pp != NULL; pp = pp->p_pptr) {
 803                                 if (pp == p) {
 804                                         error = EINVAL;
 805                                         goto fail;
 806                                 }
 807                         }
 808                 }
 809
 810
 811                 /* OK */
 812                 break;
 813
 814         case PT_CLEARSTEP:
 815                 /* Allow thread to clear single step for itself */
 816                 if (td->td_tid == tid)
 817                         break;
 818
 819                 /* FALLTHROUGH */
 820         default:
 821                 /* not being traced... */
 822                 if ((p->p_flag & P_TRACED) == 0) {
 823                         error = EPERM;
 824                         goto fail;
 825                 }
 826
 827                 /* not being traced by YOU */
 828                 if (p->p_pptr != td->td_proc) {
 829                         error = EBUSY;
 830                         goto fail;
 831                 }
 832
 833                 /* not currently stopped */
 834                 if ((p->p_flag & (P_STOPPED_SIG | P_STOPPED_TRACE)) == 0 ||
 835                     p->p_suspcount != p->p_numthreads  ||
 836                     (p->p_flag & P_WAITED) == 0) {
 837                         error = EBUSY;
 838                         goto fail;
 839                 }
 840
 841                 if ((p->p_flag & P_STOPPED_TRACE) == 0) {
 842                         static int count = 0;
 843                         if (count++ == 0)
 844                                 printf("P_STOPPED_TRACE not set.\n");
 845                 }
 846
 847                 /* OK */
 848                 break;
 849         }
 850
 851         /* Keep this process around until we finish this request. */
 852         _PHOLD(p);
 853
 854 #ifdef FIX_SSTEP
 855         /*
 856          * Single step fixup ala procfs
 857          */
 858         FIX_SSTEP(td2);
 859 #endif
 860
 861         /*
 862          * Actually do the requests
 863          */
 864
 865         td->td_retval[0] = 0;
 866
 867         switch (req) {
 868         case PT_TRACE_ME:
 869                 /* set my trace flag and "owner" so it can read/write me */
 870                 proc_set_traced(p);
 871                 if (p->p_flag & P_PPWAIT)
 872                         p->p_flag |= P_PPTRACE;
 873                 CTR1(KTR_PTRACE, "PT_TRACE_ME: pid %d", p->p_pid);
 874                 break;
 875
 876         case PT_ATTACH:
 877                 /* security check done above */
 878                 /*
 879                  * It would be nice if the tracing relationship was separate
 880                  * from the parent relationship but that would require
 881                  * another set of links in the proc struct or for "wait"
 882                  * to scan the entire proc table.  To make life easier,
 883                  * we just re-parent the process we're trying to trace.
 884                  * The old parent is remembered so we can put things back
 885                  * on a "detach".
 886                  */
 887                 proc_set_traced(p);
 888                 if (p->p_pptr != td->td_proc) {
 889                         proc_reparent(p, td->td_proc);
 890                 }
 891                 data = SIGSTOP;
 892                 CTR2(KTR_PTRACE, "PT_ATTACH: pid %d, oppid %d", p->p_pid,
 893                     p->p_oppid);
 894                 goto sendsig;   /* in PT_CONTINUE below */
 895
 896         case PT_CLEARSTEP:
 897                 CTR2(KTR_PTRACE, "PT_CLEARSTEP: tid %d (pid %d)", td2->td_tid,
 898                     p->p_pid);
 899                 error = ptrace_clear_single_step(td2);
 900                 break;
 901
 902         case PT_SETSTEP:
 903                 CTR2(KTR_PTRACE, "PT_SETSTEP: tid %d (pid %d)", td2->td_tid,
 904                     p->p_pid);
 905                 error = ptrace_single_step(td2);
 906                 break;
 907
 908         case PT_SUSPEND:
 909                 CTR2(KTR_PTRACE, "PT_SUSPEND: tid %d (pid %d)", td2->td_tid,
 910                     p->p_pid);
 911                 td2->td_dbgflags |= TDB_SUSPEND;
 912                 thread_lock(td2);
 913                 td2->td_flags |= TDF_NEEDSUSPCHK;
 914                 thread_unlock(td2);
 915                 break;
 916
 917         case PT_RESUME:
 918                 CTR2(KTR_PTRACE, "PT_RESUME: tid %d (pid %d)", td2->td_tid,
 919                     p->p_pid);
 920                 td2->td_dbgflags &= ~TDB_SUSPEND;
 921                 break;
 922
 923         case PT_FOLLOW_FORK:
 924                 CTR3(KTR_PTRACE, "PT_FOLLOW_FORK: pid %d %s -> %s", p->p_pid,
 925                     p->p_ptevents & PTRACE_FORK ? "enabled" : "disabled",
 926                     data ? "enabled" : "disabled");
 927                 if (data)
 928                         p->p_ptevents |= PTRACE_FORK;
 929                 else
 930                         p->p_ptevents &= ~PTRACE_FORK;
 931                 break;
 932
 933         case PT_LWP_EVENTS:
 934                 CTR3(KTR_PTRACE, "PT_LWP_EVENTS: pid %d %s -> %s", p->p_pid,
 935                     p->p_ptevents & PTRACE_LWP ? "enabled" : "disabled",
 936                     data ? "enabled" : "disabled");
 937                 if (data)
 938                         p->p_ptevents |= PTRACE_LWP;
 939                 else
 940                         p->p_ptevents &= ~PTRACE_LWP;
 941                 break;
 942
 943         case PT_GET_EVENT_MASK:
 944                 if (data != sizeof(p->p_ptevents)) {
 945                         error = EINVAL;
 946                         break;
 947                 }
 948                 CTR2(KTR_PTRACE, "PT_GET_EVENT_MASK: pid %d mask %#x", p->p_pid,
 949                     p->p_ptevents);
 950                 *(int *)addr = p->p_ptevents;
 951                 break;
 952
 953         case PT_SET_EVENT_MASK:
 954                 if (data != sizeof(p->p_ptevents)) {
 955                         error = EINVAL;
 956                         break;
 957                 }
 958                 tmp = *(int *)addr;
 959                 if ((tmp & ~(PTRACE_EXEC | PTRACE_SCE | PTRACE_SCX |
 960                     PTRACE_FORK | PTRACE_LWP)) != 0) {
 961                         error = EINVAL;
 962                         break;
 963                 }
 964                 CTR3(KTR_PTRACE, "PT_SET_EVENT_MASK: pid %d mask %#x -> %#x",
 965                     p->p_pid, p->p_ptevents, tmp);
 966                 p->p_ptevents = tmp;
 967                 break;
 968
 969         case PT_STEP:
 970         case PT_CONTINUE:
 971         case PT_TO_SCE:
 972         case PT_TO_SCX:
 973         case PT_SYSCALL:
 974         case PT_DETACH:
 975                 /* Zero means do not send any signal */
 976                 if (data < 0 || data > _SIG_MAXSIG) {
 977                         error = EINVAL;
 978                         break;
 979                 }
 980
 981                 switch (req) {
 982                 case PT_STEP:
 983                         CTR2(KTR_PTRACE, "PT_STEP: tid %d (pid %d)",
 984                             td2->td_tid, p->p_pid);
 985                         error = ptrace_single_step(td2);
 986                         if (error)
 987                                 goto out;
 988                         break;
 989                 case PT_CONTINUE:
 990                 case PT_TO_SCE:
 991                 case PT_TO_SCX:
 992                 case PT_SYSCALL:
 993                         if (addr != (void *)1) {
 994                                 error = ptrace_set_pc(td2,
 995                                     (u_long)(uintfptr_t)addr);
 996                                 if (error)
 997                                         goto out;
 998                         }
 999                         switch (req) {
1000                         case PT_TO_SCE:
1001                                 p->p_ptevents |= PTRACE_SCE;
1002                                 CTR4(KTR_PTRACE,
1003                     "PT_TO_SCE: pid %d, events = %#x, PC = %#lx, sig = %d",
1004                                     p->p_pid, p->p_ptevents,
1005                                     (u_long)(uintfptr_t)addr, data);
1006                                 break;
1007                         case PT_TO_SCX:
1008                                 p->p_ptevents |= PTRACE_SCX;
1009                                 CTR4(KTR_PTRACE,
1010                     "PT_TO_SCX: pid %d, events = %#x, PC = %#lx, sig = %d",
1011                                     p->p_pid, p->p_ptevents,
1012                                     (u_long)(uintfptr_t)addr, data);
1013                                 break;
1014                         case PT_SYSCALL:
1015                                 p->p_ptevents |= PTRACE_SYSCALL;
1016                                 CTR4(KTR_PTRACE,
1017                     "PT_SYSCALL: pid %d, events = %#x, PC = %#lx, sig = %d",
1018                                     p->p_pid, p->p_ptevents,
1019                                     (u_long)(uintfptr_t)addr, data);
1020                                 break;
1021                         case PT_CONTINUE:
1022                                 CTR3(KTR_PTRACE,
1023                                     "PT_CONTINUE: pid %d, PC = %#lx, sig = %d",
1024                                     p->p_pid, (u_long)(uintfptr_t)addr, data);
1025                                 break;
1026                         }
1027                         break;
1028                 case PT_DETACH:
1029                         /*
1030                          * Reset the process parent.
1031                          *
1032                          * NB: This clears P_TRACED before reparenting
1033                          * a detached process back to its original
1034                          * parent.  Otherwise the debugee will be set
1035                          * as an orphan of the debugger.
1036                          */
1037                         p->p_flag &= ~(P_TRACED | P_WAITED);
1038                         if (p->p_oppid != p->p_pptr->p_pid) {
1039                                 PROC_LOCK(p->p_pptr);
1040                                 sigqueue_take(p->p_ksi);
1041                                 PROC_UNLOCK(p->p_pptr);
1042
1043                                 pp = proc_realparent(p);
1044                                 proc_reparent(p, pp);
1045                                 if (pp == initproc)
1046                                         p->p_sigparent = SIGCHLD;
1047                                 CTR3(KTR_PTRACE,
1048                             "PT_DETACH: pid %d reparented to pid %d, sig %d",
1049                                     p->p_pid, pp->p_pid, data);
1050                         } else
1051                                 CTR2(KTR_PTRACE, "PT_DETACH: pid %d, sig %d",
1052                                     p->p_pid, data);
1053                         p->p_oppid = 0;
1054                         p->p_ptevents = 0;
1055                         FOREACH_THREAD_IN_PROC(p, td3) {
1056                                 if ((td3->td_dbgflags & TDB_FSTP) != 0) {
1057                                         sigqueue_delete(&td3->td_sigqueue,
1058                                             SIGSTOP);
1059                                 }
1060                                 td3->td_dbgflags &= ~(TDB_XSIG | TDB_FSTP);
1061                         }
1062                         if ((p->p_flag2 & P2_PTRACE_FSTP) != 0) {
1063                                 sigqueue_delete(&p->p_sigqueue, SIGSTOP);
1064                                 p->p_flag2 &= ~P2_PTRACE_FSTP;
1065                         }
1066
1067                         /* should we send SIGCHLD? */
1068                         /* childproc_continued(p); */
1069                         break;
1070                 }
1071
1072         sendsig:
1073                 if (proctree_locked) {
1074                         sx_xunlock(&proctree_lock);
1075                         proctree_locked = 0;
1076                 }
1077                 p->p_xstat = data;
1078                 p->p_xthread = NULL;
1079                 if ((p->p_flag & (P_STOPPED_SIG | P_STOPPED_TRACE)) != 0) {
1080                         /* deliver or queue signal */
1081                         td2->td_dbgflags &= ~TDB_XSIG;
1082                         td2->td_xsig = data;
1083
1084                         if (req == PT_DETACH) {
1085                                 FOREACH_THREAD_IN_PROC(p, td3)
1086                                         td3->td_dbgflags &= ~TDB_SUSPEND;
1087                         }
1088                         /*
1089                          * unsuspend all threads, to not let a thread run,
1090                          * you should use PT_SUSPEND to suspend it before
1091                          * continuing process.
1092                          */
1093                         PROC_SLOCK(p);
1094                         p->p_flag &= ~(P_STOPPED_TRACE|P_STOPPED_SIG|P_WAITED);
1095                         thread_unsuspend(p);
1096                         PROC_SUNLOCK(p);
1097                         if (req == PT_ATTACH)
1098                                 kern_psignal(p, data);
1099                 } else {
1100                         if (data)
1101                                 kern_psignal(p, data);
1102                 }
1103                 break;
1104
1105         case PT_WRITE_I:
1106         case PT_WRITE_D:
1107                 td2->td_dbgflags |= TDB_USERWR;
1108                 write = 1;
1109                 /* FALLTHROUGH */
1110         case PT_READ_I:
1111         case PT_READ_D:
1112                 PROC_UNLOCK(p);
1113                 tmp = 0;
1114                 /* write = 0 set above */
1115                 iov.iov_base = write ? (caddr_t)&data : (caddr_t)&tmp;
1116                 iov.iov_len = sizeof(int);
1117                 uio.uio_iov = &iov;
1118                 uio.uio_iovcnt = 1;
1119                 uio.uio_offset = (off_t)(uintptr_t)addr;
1120                 uio.uio_resid = sizeof(int);
1121                 uio.uio_segflg = UIO_SYSSPACE;  /* i.e.: the uap */
1122                 uio.uio_rw = write ? UIO_WRITE : UIO_READ;
1123                 uio.uio_td = td;
1124                 error = proc_rwmem(p, &uio);
1125                 if (uio.uio_resid != 0) {
1126                         /*
1127                          * XXX proc_rwmem() doesn't currently return ENOSPC,
1128                          * so I think write() can bogusly return 0.
1129                          * XXX what happens for short writes?  We don't want
1130                          * to write partial data.
1131                          * XXX proc_rwmem() returns EPERM for other invalid
1132                          * addresses.  Convert this to EINVAL.  Does this
1133                          * clobber returns of EPERM for other reasons?
1134                          */
1135                         if (error == 0 || error == ENOSPC || error == EPERM)
1136                                 error = EINVAL; /* EOF */
1137                 }
1138                 if (!write)
1139                         td->td_retval[0] = tmp;
1140                 if (error == 0) {
1141                         if (write)
1142                                 CTR3(KTR_PTRACE, "PT_WRITE: pid %d: %p <= %#x",
1143                                     p->p_pid, addr, data);
1144                         else
1145                                 CTR3(KTR_PTRACE, "PT_READ: pid %d: %p >= %#x",
1146                                     p->p_pid, addr, tmp);
1147                 }
1148                 PROC_LOCK(p);
1149                 break;
1150
1151         case PT_IO:
1152 #ifdef COMPAT_FREEBSD32
1153                 if (wrap32) {
1154                         piod32 = addr;
1155                         iov.iov_base = (void *)(uintptr_t)piod32->piod_addr;
1156                         iov.iov_len = piod32->piod_len;
1157                         uio.uio_offset = (off_t)(uintptr_t)piod32->piod_offs;
1158                         uio.uio_resid = piod32->piod_len;
1159                 } else
1160 #endif
1161                 {
1162                         piod = addr;
1163                         iov.iov_base = piod->piod_addr;
1164                         iov.iov_len = piod->piod_len;
1165                         uio.uio_offset = (off_t)(uintptr_t)piod->piod_offs;
1166                         uio.uio_resid = piod->piod_len;
1167                 }
1168                 uio.uio_iov = &iov;
1169                 uio.uio_iovcnt = 1;
1170                 uio.uio_segflg = UIO_USERSPACE;
1171                 uio.uio_td = td;
1172 #ifdef COMPAT_FREEBSD32
1173                 tmp = wrap32 ? piod32->piod_op : piod->piod_op;
1174 #else
1175                 tmp = piod->piod_op;
1176 #endif
1177                 switch (tmp) {
1178                 case PIOD_READ_D:
1179                 case PIOD_READ_I:
1180                         CTR3(KTR_PTRACE, "PT_IO: pid %d: READ (%p, %#x)",
1181                             p->p_pid, (uintptr_t)uio.uio_offset, uio.uio_resid);
1182                         uio.uio_rw = UIO_READ;
1183                         break;
1184                 case PIOD_WRITE_D:
1185                 case PIOD_WRITE_I:
1186                         CTR3(KTR_PTRACE, "PT_IO: pid %d: WRITE (%p, %#x)",
1187                             p->p_pid, (uintptr_t)uio.uio_offset, uio.uio_resid);
1188                         td2->td_dbgflags |= TDB_USERWR;
1189                         uio.uio_rw = UIO_WRITE;
1190                         break;
1191                 default:
1192                         error = EINVAL;
1193                         goto out;
1194                 }
1195                 PROC_UNLOCK(p);
1196                 error = proc_rwmem(p, &uio);
1197 #ifdef COMPAT_FREEBSD32
1198                 if (wrap32)
1199                         piod32->piod_len -= uio.uio_resid;
1200                 else
1201 #endif
1202                         piod->piod_len -= uio.uio_resid;
1203                 PROC_LOCK(p);
1204                 break;
1205
1206         case PT_KILL:
1207                 CTR1(KTR_PTRACE, "PT_KILL: pid %d", p->p_pid);
1208                 data = SIGKILL;
1209                 goto sendsig;   /* in PT_CONTINUE above */
1210
1211         case PT_SETREGS:
1212                 CTR2(KTR_PTRACE, "PT_SETREGS: tid %d (pid %d)", td2->td_tid,
1213                     p->p_pid);
1214                 td2->td_dbgflags |= TDB_USERWR;
1215                 error = PROC_WRITE(regs, td2, addr);
1216                 break;
1217
1218         case PT_GETREGS:
1219                 CTR2(KTR_PTRACE, "PT_GETREGS: tid %d (pid %d)", td2->td_tid,
1220                     p->p_pid);
1221                 error = PROC_READ(regs, td2, addr);
1222                 break;
1223
1224         case PT_SETFPREGS:
1225                 CTR2(KTR_PTRACE, "PT_SETFPREGS: tid %d (pid %d)", td2->td_tid,
1226                     p->p_pid);
1227                 td2->td_dbgflags |= TDB_USERWR;
1228                 error = PROC_WRITE(fpregs, td2, addr);
1229                 break;
1230
1231         case PT_GETFPREGS:
1232                 CTR2(KTR_PTRACE, "PT_GETFPREGS: tid %d (pid %d)", td2->td_tid,
1233                     p->p_pid);
1234                 error = PROC_READ(fpregs, td2, addr);
1235                 break;
1236
1237         case PT_SETDBREGS:
1238                 CTR2(KTR_PTRACE, "PT_SETDBREGS: tid %d (pid %d)", td2->td_tid,
1239                     p->p_pid);
1240                 td2->td_dbgflags |= TDB_USERWR;
1241                 error = PROC_WRITE(dbregs, td2, addr);
1242                 break;
1243
1244         case PT_GETDBREGS:
1245                 CTR2(KTR_PTRACE, "PT_GETDBREGS: tid %d (pid %d)", td2->td_tid,
1246                     p->p_pid);
1247                 error = PROC_READ(dbregs, td2, addr);
1248                 break;
1249
1250         case PT_LWPINFO:
1251                 if (data <= 0 ||
1252 #ifdef COMPAT_FREEBSD32
1253                     (!wrap32 && data > sizeof(*pl)) ||
1254                     (wrap32 && data > sizeof(*pl32))) {
1255 #else
1256                     data > sizeof(*pl)) {
1257 #endif
1258                         error = EINVAL;
1259                         break;
1260                 }
1261 #ifdef COMPAT_FREEBSD32
1262                 if (wrap32) {
1263                         pl = &plr;
1264                         pl32 = addr;
1265                 } else
1266 #endif
1267                 pl = addr;
1268                 pl->pl_lwpid = td2->td_tid;
1269                 pl->pl_event = PL_EVENT_NONE;
1270                 pl->pl_flags = 0;
1271                 if (td2->td_dbgflags & TDB_XSIG) {
1272                         pl->pl_event = PL_EVENT_SIGNAL;
1273                         if (td2->td_dbgksi.ksi_signo != 0 &&
1274 #ifdef COMPAT_FREEBSD32
1275                             ((!wrap32 && data >= offsetof(struct ptrace_lwpinfo,
1276                             pl_siginfo) + sizeof(pl->pl_siginfo)) ||
1277                             (wrap32 && data >= offsetof(struct ptrace_lwpinfo32,
1278                             pl_siginfo) + sizeof(struct siginfo32)))
1279 #else
1280                             data >= offsetof(struct ptrace_lwpinfo, pl_siginfo)
1281                             + sizeof(pl->pl_siginfo)
1282 #endif
1283                         ){
1284                                 pl->pl_flags |= PL_FLAG_SI;
1285                                 pl->pl_siginfo = td2->td_dbgksi.ksi_info;
1286                         }
1287                 }
1288                 if ((pl->pl_flags & PL_FLAG_SI) == 0)
1289                         bzero(&pl->pl_siginfo, sizeof(pl->pl_siginfo));
1290                 if (td2->td_dbgflags & TDB_SCE)
1291                         pl->pl_flags |= PL_FLAG_SCE;
1292                 else if (td2->td_dbgflags & TDB_SCX)
1293                         pl->pl_flags |= PL_FLAG_SCX;
1294                 if (td2->td_dbgflags & TDB_EXEC)
1295                         pl->pl_flags |= PL_FLAG_EXEC;
1296                 if (td2->td_dbgflags & TDB_FORK) {
1297                         pl->pl_flags |= PL_FLAG_FORKED;
1298                         pl->pl_child_pid = td2->td_dbg_forked;
1299                 }
1300                 if (td2->td_dbgflags & TDB_CHILD)
1301                         pl->pl_flags |= PL_FLAG_CHILD;
1302                 if (td2->td_dbgflags & TDB_BORN)
1303                         pl->pl_flags |= PL_FLAG_BORN;
1304                 if (td2->td_dbgflags & TDB_EXIT)
1305                         pl->pl_flags |= PL_FLAG_EXITED;
1306                 pl->pl_sigmask = td2->td_sigmask;
1307                 pl->pl_siglist = td2->td_siglist;
1308                 strcpy(pl->pl_tdname, td2->td_name);
1309                 if ((td2->td_dbgflags & (TDB_SCE | TDB_SCX)) != 0) {
1310                         pl->pl_syscall_code = td2->td_dbg_sc_code;
1311                         pl->pl_syscall_narg = td2->td_dbg_sc_narg;
1312                 } else {
1313                         pl->pl_syscall_code = 0;
1314                         pl->pl_syscall_narg = 0;
1315                 }
1316 #ifdef COMPAT_FREEBSD32
1317                 if (wrap32)
1318                         ptrace_lwpinfo_to32(pl, pl32);
1319 #endif
1320                 CTR6(KTR_PTRACE,
1321     "PT_LWPINFO: tid %d (pid %d) event %d flags %#x child pid %d syscall %d",
1322                     td2->td_tid, p->p_pid, pl->pl_event, pl->pl_flags,
1323                     pl->pl_child_pid, pl->pl_syscall_code);
1324                 break;
1325
1326         case PT_GETNUMLWPS:
1327                 CTR2(KTR_PTRACE, "PT_GETNUMLWPS: pid %d: %d threads", p->p_pid,
1328                     p->p_numthreads);
1329                 td->td_retval[0] = p->p_numthreads;
1330                 break;
1331
1332         case PT_GETLWPLIST:
1333                 CTR3(KTR_PTRACE, "PT_GETLWPLIST: pid %d: data %d, actual %d",
1334                     p->p_pid, data, p->p_numthreads);
1335                 if (data <= 0) {
1336                         error = EINVAL;
1337                         break;
1338                 }
1339                 num = imin(p->p_numthreads, data);
1340                 PROC_UNLOCK(p);
1341                 buf = malloc(num * sizeof(lwpid_t), M_TEMP, M_WAITOK);
1342                 tmp = 0;
1343                 PROC_LOCK(p);
1344                 FOREACH_THREAD_IN_PROC(p, td2) {
1345                         if (tmp >= num)
1346                                 break;
1347                         buf[tmp++] = td2->td_tid;
1348                 }
1349                 PROC_UNLOCK(p);
1350                 error = copyout(buf, addr, tmp * sizeof(lwpid_t));
1351                 free(buf, M_TEMP);
1352                 if (!error)
1353                         td->td_retval[0] = tmp;
1354                 PROC_LOCK(p);
1355                 break;
1356
1357         case PT_VM_TIMESTAMP:
1358                 CTR2(KTR_PTRACE, "PT_VM_TIMESTAMP: pid %d: timestamp %d",
1359                     p->p_pid, p->p_vmspace->vm_map.timestamp);
1360                 td->td_retval[0] = p->p_vmspace->vm_map.timestamp;
1361                 break;
1362
1363         case PT_VM_ENTRY:
1364                 PROC_UNLOCK(p);
1365 #ifdef COMPAT_FREEBSD32
1366                 if (wrap32)
1367                         error = ptrace_vm_entry32(td, p, addr);
1368                 else
1369 #endif
1370                 error = ptrace_vm_entry(td, p, addr);
1371                 PROC_LOCK(p);
1372                 break;
1373
1374         default:
1375 #ifdef __HAVE_PTRACE_MACHDEP
1376                 if (req >= PT_FIRSTMACH) {
1377                         PROC_UNLOCK(p);
1378                         error = cpu_ptrace(td2, req, addr, data);
1379                         PROC_LOCK(p);
1380                 } else
1381 #endif
1382                         /* Unknown request. */
1383                         error = EINVAL;
1384                 break;
1385         }
1386
1387 out:
1388         /* Drop our hold on this process now that the request has completed. */
1389         _PRELE(p);
1390 fail:
1391         PROC_UNLOCK(p);
1392         if (proctree_locked)
1393                 sx_xunlock(&proctree_lock);
1394         return (error);
1395 }
1396 #undef PROC_READ
1397 #undef PROC_WRITE
1398
1399 /*
1400  * Stop a process because of a debugging event;
1401  * stay stopped until p->p_step is cleared
1402  * (cleared by PIOCCONT in procfs).
1403  */
1404 void
1405 stopevent(struct proc *p, unsigned int event, unsigned int val)
1406 {
1407
1408         PROC_LOCK_ASSERT(p, MA_OWNED);
1409         p->p_step = 1;
1410         CTR3(KTR_PTRACE, "stopevent: pid %d event %u val %u", p->p_pid, event,
1411             val);
1412         do {
1413                 p->p_xstat = val;
1414                 p->p_xthread = NULL;
1415                 p->p_stype = event;     /* Which event caused the stop? */
1416                 wakeup(&p->p_stype);    /* Wake up any PIOCWAIT'ing procs */
1417                 msleep(&p->p_step, &p->p_mtx, PWAIT, "stopevent", 0);
1418         } while (p->p_step);
1419 }