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/pioctl.h>
  45 #include <sys/priv.h>
  46 #include <sys/proc.h>
  47 #include <sys/vnode.h>
  48 #include <sys/ptrace.h>
  49 #include <sys/rwlock.h>
  50 #include <sys/sx.h>
  51 #include <sys/malloc.h>
  52 #include <sys/signalvar.h>
  53
  54 #include <machine/reg.h>
  55
  56 #include <security/audit/audit.h>
  57
  58 #include <vm/vm.h>
  59 #include <vm/pmap.h>
  60 #include <vm/vm_extern.h>
  61 #include <vm/vm_map.h>
  62 #include <vm/vm_kern.h>
  63 #include <vm/vm_object.h>
  64 #include <vm/vm_page.h>
  65 #include <vm/vm_param.h>
  66
  67 #ifdef COMPAT_FREEBSD32
  68 #include <sys/procfs.h>
  69 #include <compat/freebsd32/freebsd32_signal.h>
  70
  71 struct ptrace_io_desc32 {
  72         int             piod_op;
  73         uint32_t        piod_offs;
  74         uint32_t        piod_addr;
  75         uint32_t        piod_len;
  76 };
  77
  78 struct ptrace_vm_entry32 {
  79         int             pve_entry;
  80         int             pve_timestamp;
  81         uint32_t        pve_start;
  82         uint32_t        pve_end;
  83         uint32_t        pve_offset;
  84         u_int           pve_prot;
  85         u_int           pve_pathlen;
  86         int32_t         pve_fileid;
  87         u_int           pve_fsid;
  88         uint32_t        pve_path;
  89 };
  90
  91 struct ptrace_lwpinfo32 {
  92         lwpid_t pl_lwpid;       /* LWP described. */
  93         int     pl_event;       /* Event that stopped the LWP. */
  94         int     pl_flags;       /* LWP flags. */
  95         sigset_t        pl_sigmask;     /* LWP signal mask */
  96         sigset_t        pl_siglist;     /* LWP pending signal */
  97         struct siginfo32 pl_siginfo;    /* siginfo for signal */
  98         char    pl_tdname[MAXCOMLEN + 1];       /* LWP name. */
  99         int     pl_child_pid;           /* New child pid */
 100 };
 101
 102 #endif
 103
 104 /*
 105  * Functions implemented using PROC_ACTION():
 106  *
 107  * proc_read_regs(proc, regs)
 108  *      Get the current user-visible register set from the process
 109  *      and copy it into the regs structure (<machine/reg.h>).
 110  *      The process is stopped at the time read_regs is called.
 111  *
 112  * proc_write_regs(proc, regs)
 113  *      Update the current register set from the passed in regs
 114  *      structure.  Take care to avoid clobbering special CPU
 115  *      registers or privileged bits in the PSL.
 116  *      Depending on the architecture this may have fix-up work to do,
 117  *      especially if the IAR or PCW are modified.
 118  *      The process is stopped at the time write_regs is called.
 119  *
 120  * proc_read_fpregs, proc_write_fpregs
 121  *      deal with the floating point register set, otherwise as above.
 122  *
 123  * proc_read_dbregs, proc_write_dbregs
 124  *      deal with the processor debug register set, otherwise as above.
 125  *
 126  * proc_sstep(proc)
 127  *      Arrange for the process to trap after executing a single instruction.
 128  */
 129
 130 #define PROC_ACTION(action) do {                                        \
 131         int error;                                                      \
 132                                                                         \
 133         PROC_LOCK_ASSERT(td->td_proc, MA_OWNED);                        \
 134         if ((td->td_proc->p_flag & P_INMEM) == 0)                       \
 135                 error = EIO;                                            \
 136         else                                                            \
 137                 error = (action);                                       \
 138         return (error);                                                 \
 139 } while(0)
 140
 141 int
 142 proc_read_regs(struct thread *td, struct reg *regs)
 143 {
 144
 145         PROC_ACTION(fill_regs(td, regs));
 146 }
 147
 148 int
 149 proc_write_regs(struct thread *td, struct reg *regs)
 150 {
 151
 152         PROC_ACTION(set_regs(td, regs));
 153 }
 154
 155 int
 156 proc_read_dbregs(struct thread *td, struct dbreg *dbregs)
 157 {
 158
 159         PROC_ACTION(fill_dbregs(td, dbregs));
 160 }
 161
 162 int
 163 proc_write_dbregs(struct thread *td, struct dbreg *dbregs)
 164 {
 165
 166         PROC_ACTION(set_dbregs(td, dbregs));
 167 }
 168
 169 /*
 170  * Ptrace doesn't support fpregs at all, and there are no security holes
 171  * or translations for fpregs, so we can just copy them.
 172  */
 173 int
 174 proc_read_fpregs(struct thread *td, struct fpreg *fpregs)
 175 {
 176
 177         PROC_ACTION(fill_fpregs(td, fpregs));
 178 }
 179
 180 int
 181 proc_write_fpregs(struct thread *td, struct fpreg *fpregs)
 182 {
 183
 184         PROC_ACTION(set_fpregs(td, fpregs));
 185 }
 186
 187 #ifdef COMPAT_FREEBSD32
 188 /* For 32 bit binaries, we need to expose the 32 bit regs layouts. */
 189 int
 190 proc_read_regs32(struct thread *td, struct reg32 *regs32)
 191 {
 192
 193         PROC_ACTION(fill_regs32(td, regs32));
 194 }
 195
 196 int
 197 proc_write_regs32(struct thread *td, struct reg32 *regs32)
 198 {
 199
 200         PROC_ACTION(set_regs32(td, regs32));
 201 }
 202
 203 int
 204 proc_read_dbregs32(struct thread *td, struct dbreg32 *dbregs32)
 205 {
 206
 207         PROC_ACTION(fill_dbregs32(td, dbregs32));
 208 }
 209
 210 int
 211 proc_write_dbregs32(struct thread *td, struct dbreg32 *dbregs32)
 212 {
 213
 214         PROC_ACTION(set_dbregs32(td, dbregs32));
 215 }
 216
 217 int
 218 proc_read_fpregs32(struct thread *td, struct fpreg32 *fpregs32)
 219 {
 220
 221         PROC_ACTION(fill_fpregs32(td, fpregs32));
 222 }
 223
 224 int
 225 proc_write_fpregs32(struct thread *td, struct fpreg32 *fpregs32)
 226 {
 227
 228         PROC_ACTION(set_fpregs32(td, fpregs32));
 229 }
 230 #endif
 231
 232 int
 233 proc_sstep(struct thread *td)
 234 {
 235
 236         PROC_ACTION(ptrace_single_step(td));
 237 }
 238
 239 int
 240 proc_rwmem(struct proc *p, struct uio *uio)
 241 {
 242         vm_map_t map;
 243         vm_offset_t pageno;             /* page number */
 244         vm_prot_t reqprot;
 245         int error, fault_flags, page_offset, writing;
 246
 247         /*
 248          * Assert that someone has locked this vmspace.  (Should be
 249          * curthread but we can't assert that.)  This keeps the process
 250          * from exiting out from under us until this operation completes.
 251          */
 252         KASSERT(p->p_lock >= 1, ("%s: process %p (pid %d) not held", __func__,
 253             p, p->p_pid));
 254
 255         /*
 256          * The map we want...
 257          */
 258         map = &p->p_vmspace->vm_map;
 259
 260         /*
 261          * If we are writing, then we request vm_fault() to create a private
 262          * copy of each page.  Since these copies will not be writeable by the
 263          * process, we must explicity request that they be dirtied.
 264          */
 265         writing = uio->uio_rw == UIO_WRITE;
 266         reqprot = writing ? VM_PROT_COPY | VM_PROT_READ : VM_PROT_READ;
 267         fault_flags = writing ? VM_FAULT_DIRTY : VM_FAULT_NORMAL;
 268
 269         /*
 270          * Only map in one page at a time.  We don't have to, but it
 271          * makes things easier.  This way is trivial - right?
 272          */
 273         do {
 274                 vm_offset_t uva;
 275                 u_int len;
 276                 vm_page_t m;
 277
 278                 uva = (vm_offset_t)uio->uio_offset;
 279
 280                 /*
 281                  * Get the page number of this segment.
 282                  */
 283                 pageno = trunc_page(uva);
 284                 page_offset = uva - pageno;
 285
 286                 /*
 287                  * How many bytes to copy
 288                  */
 289                 len = min(PAGE_SIZE - page_offset, uio->uio_resid);
 290
 291                 /*
 292                  * Fault and hold the page on behalf of the process.
 293                  */
 294                 error = vm_fault_hold(map, pageno, reqprot, fault_flags, &m);
 295                 if (error != KERN_SUCCESS) {
 296                         if (error == KERN_RESOURCE_SHORTAGE)
 297                                 error = ENOMEM;
 298                         else
 299                                 error = EFAULT;
 300                         break;
 301                 }
 302
 303                 /*
 304                  * Now do the i/o move.
 305                  */
 306                 error = uiomove_fromphys(&m, page_offset, len, uio);
 307
 308                 /* Make the I-cache coherent for breakpoints. */
 309                 if (writing && error == 0) {
 310                         vm_map_lock_read(map);
 311                         if (vm_map_check_protection(map, pageno, pageno +
 312                             PAGE_SIZE, VM_PROT_EXECUTE))
 313                                 vm_sync_icache(map, uva, len);
 314                         vm_map_unlock_read(map);
 315                 }
 316
 317                 /*
 318                  * Release the page.
 319                  */
 320                 vm_page_lock(m);
 321                 vm_page_unhold(m);
 322                 vm_page_unlock(m);
 323
 324         } while (error == 0 && uio->uio_resid > 0);
 325
 326         return (error);
 327 }
 328
 329 static int
 330 ptrace_vm_entry(struct thread *td, struct proc *p, struct ptrace_vm_entry *pve)
 331 {
 332         struct vattr vattr;
 333         vm_map_t map;
 334         vm_map_entry_t entry;
 335         vm_object_t obj, tobj, lobj;
 336         struct vmspace *vm;
 337         struct vnode *vp;
 338         char *freepath, *fullpath;
 339         u_int pathlen;
 340         int error, index;
 341
 342         error = 0;
 343         obj = NULL;
 344
 345         vm = vmspace_acquire_ref(p);
 346         map = &vm->vm_map;
 347         vm_map_lock_read(map);
 348
 349         do {
 350                 entry = map->header.next;
 351                 index = 0;
 352                 while (index < pve->pve_entry && entry != &map->header) {
 353                         entry = entry->next;
 354                         index++;
 355                 }
 356                 if (index != pve->pve_entry) {
 357                         error = EINVAL;
 358                         break;
 359                 }
 360                 while (entry != &map->header &&
 361                     (entry->eflags & MAP_ENTRY_IS_SUB_MAP) != 0) {
 362                         entry = entry->next;
 363                         index++;
 364                 }
 365                 if (entry == &map->header) {
 366                         error = ENOENT;
 367                         break;
 368                 }
 369
 370                 /* We got an entry. */
 371                 pve->pve_entry = index + 1;
 372                 pve->pve_timestamp = map->timestamp;
 373                 pve->pve_start = entry->start;
 374                 pve->pve_end = entry->end - 1;
 375                 pve->pve_offset = entry->offset;
 376                 pve->pve_prot = entry->protection;
 377
 378                 /* Backing object's path needed? */
 379                 if (pve->pve_pathlen == 0)
 380                         break;
 381
 382                 pathlen = pve->pve_pathlen;
 383                 pve->pve_pathlen = 0;
 384
 385                 obj = entry->object.vm_object;
 386                 if (obj != NULL)
 387                         VM_OBJECT_RLOCK(obj);
 388         } while (0);
 389
 390         vm_map_unlock_read(map);
 391         vmspace_free(vm);
 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         if (error == 0)
 437                 CTR3(KTR_PTRACE, "PT_VM_ENTRY: pid %d, entry %d, start %p",
 438                     p->p_pid, pve->pve_entry, pve->pve_start);
 439
 440         return (error);
 441 }
 442
 443 #ifdef COMPAT_FREEBSD32
 444 static int
 445 ptrace_vm_entry32(struct thread *td, struct proc *p,
 446     struct ptrace_vm_entry32 *pve32)
 447 {
 448         struct ptrace_vm_entry pve;
 449         int error;
 450
 451         pve.pve_entry = pve32->pve_entry;
 452         pve.pve_pathlen = pve32->pve_pathlen;
 453         pve.pve_path = (void *)(uintptr_t)pve32->pve_path;
 454
 455         error = ptrace_vm_entry(td, p, &pve);
 456         if (error == 0) {
 457                 pve32->pve_entry = pve.pve_entry;
 458                 pve32->pve_timestamp = pve.pve_timestamp;
 459                 pve32->pve_start = pve.pve_start;
 460                 pve32->pve_end = pve.pve_end;
 461                 pve32->pve_offset = pve.pve_offset;
 462                 pve32->pve_prot = pve.pve_prot;
 463                 pve32->pve_fileid = pve.pve_fileid;
 464                 pve32->pve_fsid = pve.pve_fsid;
 465         }
 466
 467         pve32->pve_pathlen = pve.pve_pathlen;
 468         return (error);
 469 }
 470
 471 static void
 472 ptrace_lwpinfo_to32(const struct ptrace_lwpinfo *pl,
 473     struct ptrace_lwpinfo32 *pl32)
 474 {
 475
 476         pl32->pl_lwpid = pl->pl_lwpid;
 477         pl32->pl_event = pl->pl_event;
 478         pl32->pl_flags = pl->pl_flags;
 479         pl32->pl_sigmask = pl->pl_sigmask;
 480         pl32->pl_siglist = pl->pl_siglist;
 481         siginfo_to_siginfo32(&pl->pl_siginfo, &pl32->pl_siginfo);
 482         strcpy(pl32->pl_tdname, pl->pl_tdname);
 483         pl32->pl_child_pid = pl->pl_child_pid;
 484 }
 485 #endif /* COMPAT_FREEBSD32 */
 486
 487 /*
 488  * Process debugging system call.
 489  */
 490 #ifndef _SYS_SYSPROTO_H_
 491 struct ptrace_args {
 492         int     req;
 493         pid_t   pid;
 494         caddr_t addr;
 495         int     data;
 496 };
 497 #endif
 498
 499 #ifdef COMPAT_FREEBSD32
 500 /*
 501  * This CPP subterfuge is to try and reduce the number of ifdefs in
 502  * the body of the code.
 503  *   COPYIN(uap->addr, &r.reg, sizeof r.reg);
 504  * becomes either:
 505  *   copyin(uap->addr, &r.reg, sizeof r.reg);
 506  * or
 507  *   copyin(uap->addr, &r.reg32, sizeof r.reg32);
 508  * .. except this is done at runtime.
 509  */
 510 #define COPYIN(u, k, s)         wrap32 ? \
 511         copyin(u, k ## 32, s ## 32) : \
 512         copyin(u, k, s)
 513 #define COPYOUT(k, u, s)        wrap32 ? \
 514         copyout(k ## 32, u, s ## 32) : \
 515         copyout(k, u, s)
 516 #else
 517 #define COPYIN(u, k, s)         copyin(u, k, s)
 518 #define COPYOUT(k, u, s)        copyout(k, u, s)
 519 #endif
 520 int
 521 sys_ptrace(struct thread *td, struct ptrace_args *uap)
 522 {
 523         /*
 524          * XXX this obfuscation is to reduce stack usage, but the register
 525          * structs may be too large to put on the stack anyway.
 526          */
 527         union {
 528                 struct ptrace_io_desc piod;
 529                 struct ptrace_lwpinfo pl;
 530                 struct ptrace_vm_entry pve;
 531                 struct dbreg dbreg;
 532                 struct fpreg fpreg;
 533                 struct reg reg;
 534 #ifdef COMPAT_FREEBSD32
 535                 struct dbreg32 dbreg32;
 536                 struct fpreg32 fpreg32;
 537                 struct reg32 reg32;
 538                 struct ptrace_io_desc32 piod32;
 539                 struct ptrace_lwpinfo32 pl32;
 540                 struct ptrace_vm_entry32 pve32;
 541 #endif
 542         } r;
 543         void *addr;
 544         int error = 0;
 545 #ifdef COMPAT_FREEBSD32
 546         int wrap32 = 0;
 547
 548         if (SV_CURPROC_FLAG(SV_ILP32))
 549                 wrap32 = 1;
 550 #endif
 551         AUDIT_ARG_PID(uap->pid);
 552         AUDIT_ARG_CMD(uap->req);
 553         AUDIT_ARG_VALUE(uap->data);
 554         addr = &r;
 555         switch (uap->req) {
 556         case PT_GETREGS:
 557         case PT_GETFPREGS:
 558         case PT_GETDBREGS:
 559         case PT_LWPINFO:
 560                 break;
 561         case PT_SETREGS:
 562                 error = COPYIN(uap->addr, &r.reg, sizeof r.reg);
 563                 break;
 564         case PT_SETFPREGS:
 565                 error = COPYIN(uap->addr, &r.fpreg, sizeof r.fpreg);
 566                 break;
 567         case PT_SETDBREGS:
 568                 error = COPYIN(uap->addr, &r.dbreg, sizeof r.dbreg);
 569                 break;
 570         case PT_IO:
 571                 error = COPYIN(uap->addr, &r.piod, sizeof r.piod);
 572                 break;
 573         case PT_VM_ENTRY:
 574                 error = COPYIN(uap->addr, &r.pve, sizeof r.pve);
 575                 break;
 576         default:
 577                 addr = uap->addr;
 578                 break;
 579         }
 580         if (error)
 581                 return (error);
 582
 583         error = kern_ptrace(td, uap->req, uap->pid, addr, uap->data);
 584         if (error)
 585                 return (error);
 586
 587         switch (uap->req) {
 588         case PT_VM_ENTRY:
 589                 error = COPYOUT(&r.pve, uap->addr, sizeof r.pve);
 590                 break;
 591         case PT_IO:
 592                 error = COPYOUT(&r.piod, uap->addr, sizeof r.piod);
 593                 break;
 594         case PT_GETREGS:
 595                 error = COPYOUT(&r.reg, uap->addr, sizeof r.reg);
 596                 break;
 597         case PT_GETFPREGS:
 598                 error = COPYOUT(&r.fpreg, uap->addr, sizeof r.fpreg);
 599                 break;
 600         case PT_GETDBREGS:
 601                 error = COPYOUT(&r.dbreg, uap->addr, sizeof r.dbreg);
 602                 break;
 603         case PT_LWPINFO:
 604                 error = copyout(&r.pl, uap->addr, uap->data);
 605                 break;
 606         }
 607
 608         return (error);
 609 }
 610 #undef COPYIN
 611 #undef COPYOUT
 612
 613 #ifdef COMPAT_FREEBSD32
 614 /*
 615  *   PROC_READ(regs, td2, addr);
 616  * becomes either:
 617  *   proc_read_regs(td2, addr);
 618  * or
 619  *   proc_read_regs32(td2, addr);
 620  * .. except this is done at runtime.  There is an additional
 621  * complication in that PROC_WRITE disallows 32 bit consumers
 622  * from writing to 64 bit address space targets.
 623  */
 624 #define PROC_READ(w, t, a)      wrap32 ? \
 625         proc_read_ ## w ## 32(t, a) : \
 626         proc_read_ ## w (t, a)
 627 #define PROC_WRITE(w, t, a)     wrap32 ? \
 628         (safe ? proc_write_ ## w ## 32(t, a) : EINVAL ) : \
 629         proc_write_ ## w (t, a)
 630 #else
 631 #define PROC_READ(w, t, a)      proc_read_ ## w (t, a)
 632 #define PROC_WRITE(w, t, a)     proc_write_ ## w (t, a)
 633 #endif
 634
 635 int
 636 kern_ptrace(struct thread *td, int req, pid_t pid, void *addr, int data)
 637 {
 638         struct iovec iov;
 639         struct uio uio;
 640         struct proc *curp, *p, *pp;
 641         struct thread *td2 = NULL, *td3;
 642         struct ptrace_io_desc *piod = NULL;
 643         struct ptrace_lwpinfo *pl;
 644         int error, write, tmp, num;
 645         int proctree_locked = 0;
 646         lwpid_t tid = 0, *buf;
 647 #ifdef COMPAT_FREEBSD32
 648         int wrap32 = 0, safe = 0;
 649         struct ptrace_io_desc32 *piod32 = NULL;
 650         struct ptrace_lwpinfo32 *pl32 = NULL;
 651         struct ptrace_lwpinfo plr;
 652 #endif
 653
 654         curp = td->td_proc;
 655
 656         /* Lock proctree before locking the process. */
 657         switch (req) {
 658         case PT_TRACE_ME:
 659         case PT_ATTACH:
 660         case PT_STEP:
 661         case PT_CONTINUE:
 662         case PT_TO_SCE:
 663         case PT_TO_SCX:
 664         case PT_SYSCALL:
 665         case PT_FOLLOW_FORK:
 666         case PT_DETACH:
 667                 sx_xlock(&proctree_lock);
 668                 proctree_locked = 1;
 669                 break;
 670         default:
 671                 break;
 672         }
 673
 674         write = 0;
 675         if (req == PT_TRACE_ME) {
 676                 p = td->td_proc;
 677                 PROC_LOCK(p);
 678         } else {
 679                 if (pid <= PID_MAX) {
 680                         if ((p = pfind(pid)) == NULL) {
 681                                 if (proctree_locked)
 682                                         sx_xunlock(&proctree_lock);
 683                                 return (ESRCH);
 684                         }
 685                 } else {
 686                         td2 = tdfind(pid, -1);
 687                         if (td2 == NULL) {
 688                                 if (proctree_locked)
 689                                         sx_xunlock(&proctree_lock);
 690                                 return (ESRCH);
 691                         }
 692                         p = td2->td_proc;
 693                         tid = pid;
 694                         pid = p->p_pid;
 695                 }
 696         }
 697         AUDIT_ARG_PROCESS(p);
 698
 699         if ((p->p_flag & P_WEXIT) != 0) {
 700                 error = ESRCH;
 701                 goto fail;
 702         }
 703         if ((error = p_cansee(td, p)) != 0)
 704                 goto fail;
 705
 706         if ((error = p_candebug(td, p)) != 0)
 707                 goto fail;
 708
 709         /*
 710          * System processes can't be debugged.
 711          */
 712         if ((p->p_flag & P_SYSTEM) != 0) {
 713                 error = EINVAL;
 714                 goto fail;
 715         }
 716
 717         if (tid == 0) {
 718                 if ((p->p_flag & P_STOPPED_TRACE) != 0) {
 719                         KASSERT(p->p_xthread != NULL, ("NULL p_xthread"));
 720                         td2 = p->p_xthread;
 721                 } else {
 722                         td2 = FIRST_THREAD_IN_PROC(p);
 723                 }
 724                 tid = td2->td_tid;
 725         }
 726
 727 #ifdef COMPAT_FREEBSD32
 728         /*
 729          * Test if we're a 32 bit client and what the target is.
 730          * Set the wrap controls accordingly.
 731          */
 732         if (SV_CURPROC_FLAG(SV_ILP32)) {
 733                 if (SV_PROC_FLAG(td2->td_proc, SV_ILP32))
 734                         safe = 1;
 735                 wrap32 = 1;
 736         }
 737 #endif
 738         /*
 739          * Permissions check
 740          */
 741         switch (req) {
 742         case PT_TRACE_ME:
 743                 /* Always legal. */
 744                 break;
 745
 746         case PT_ATTACH:
 747                 /* Self */
 748                 if (p->p_pid == td->td_proc->p_pid) {
 749                         error = EINVAL;
 750                         goto fail;
 751                 }
 752
 753                 /* Already traced */
 754                 if (p->p_flag & P_TRACED) {
 755                         error = EBUSY;
 756                         goto fail;
 757                 }
 758
 759                 /* Can't trace an ancestor if you're being traced. */
 760                 if (curp->p_flag & P_TRACED) {
 761                         for (pp = curp->p_pptr; pp != NULL; pp = pp->p_pptr) {
 762                                 if (pp == p) {
 763                                         error = EINVAL;
 764                                         goto fail;
 765                                 }
 766                         }
 767                 }
 768
 769
 770                 /* OK */
 771                 break;
 772
 773         case PT_CLEARSTEP:
 774                 /* Allow thread to clear single step for itself */
 775                 if (td->td_tid == tid)
 776                         break;
 777
 778                 /* FALLTHROUGH */
 779         default:
 780                 /* not being traced... */
 781                 if ((p->p_flag & P_TRACED) == 0) {
 782                         error = EPERM;
 783                         goto fail;
 784                 }
 785
 786                 /* not being traced by YOU */
 787                 if (p->p_pptr != td->td_proc) {
 788                         error = EBUSY;
 789                         goto fail;
 790                 }
 791
 792                 /* not currently stopped */
 793                 if ((p->p_flag & (P_STOPPED_SIG | P_STOPPED_TRACE)) == 0 ||
 794                     p->p_suspcount != p->p_numthreads  ||
 795                     (p->p_flag & P_WAITED) == 0) {
 796                         error = EBUSY;
 797                         goto fail;
 798                 }
 799
 800                 if ((p->p_flag & P_STOPPED_TRACE) == 0) {
 801                         static int count = 0;
 802                         if (count++ == 0)
 803                                 printf("P_STOPPED_TRACE not set.\n");
 804                 }
 805
 806                 /* OK */
 807                 break;
 808         }
 809
 810         /* Keep this process around until we finish this request. */
 811         _PHOLD(p);
 812
 813 #ifdef FIX_SSTEP
 814         /*
 815          * Single step fixup ala procfs
 816          */
 817         FIX_SSTEP(td2);
 818 #endif
 819
 820         /*
 821          * Actually do the requests
 822          */
 823
 824         td->td_retval[0] = 0;
 825
 826         switch (req) {
 827         case PT_TRACE_ME:
 828                 /* set my trace flag and "owner" so it can read/write me */
 829                 p->p_flag |= P_TRACED;
 830                 if (p->p_flag & P_PPWAIT)
 831                         p->p_flag |= P_PPTRACE;
 832                 p->p_oppid = p->p_pptr->p_pid;
 833                 CTR1(KTR_PTRACE, "PT_TRACE_ME: pid %d", p->p_pid);
 834                 break;
 835
 836         case PT_ATTACH:
 837                 /* security check done above */
 838                 /*
 839                  * It would be nice if the tracing relationship was separate
 840                  * from the parent relationship but that would require
 841                  * another set of links in the proc struct or for "wait"
 842                  * to scan the entire proc table.  To make life easier,
 843                  * we just re-parent the process we're trying to trace.
 844                  * The old parent is remembered so we can put things back
 845                  * on a "detach".
 846                  */
 847                 p->p_flag |= P_TRACED;
 848                 p->p_oppid = p->p_pptr->p_pid;
 849                 if (p->p_pptr != td->td_proc) {
 850                         proc_reparent(p, td->td_proc);
 851                 }
 852                 data = SIGSTOP;
 853                 CTR2(KTR_PTRACE, "PT_ATTACH: pid %d, oppid %d", p->p_pid,
 854                     p->p_oppid);
 855                 goto sendsig;   /* in PT_CONTINUE below */
 856
 857         case PT_CLEARSTEP:
 858                 CTR2(KTR_PTRACE, "PT_CLEARSTEP: tid %d (pid %d)", td2->td_tid,
 859                     p->p_pid);
 860                 error = ptrace_clear_single_step(td2);
 861                 break;
 862
 863         case PT_SETSTEP:
 864                 CTR2(KTR_PTRACE, "PT_SETSTEP: tid %d (pid %d)", td2->td_tid,
 865                     p->p_pid);
 866                 error = ptrace_single_step(td2);
 867                 break;
 868
 869         case PT_SUSPEND:
 870                 CTR2(KTR_PTRACE, "PT_SUSPEND: tid %d (pid %d)", td2->td_tid,
 871                     p->p_pid);
 872                 td2->td_dbgflags |= TDB_SUSPEND;
 873                 thread_lock(td2);
 874                 td2->td_flags |= TDF_NEEDSUSPCHK;
 875                 thread_unlock(td2);
 876                 break;
 877
 878         case PT_RESUME:
 879                 CTR2(KTR_PTRACE, "PT_RESUME: tid %d (pid %d)", td2->td_tid,
 880                     p->p_pid);
 881                 td2->td_dbgflags &= ~TDB_SUSPEND;
 882                 break;
 883
 884         case PT_FOLLOW_FORK:
 885                 CTR3(KTR_PTRACE, "PT_FOLLOW_FORK: pid %d %s -> %s", p->p_pid,
 886                     p->p_flag & P_FOLLOWFORK ? "enabled" : "disabled",
 887                     data ? "enabled" : "disabled");
 888                 if (data)
 889                         p->p_flag |= P_FOLLOWFORK;
 890                 else
 891                         p->p_flag &= ~P_FOLLOWFORK;
 892                 break;
 893
 894         case PT_STEP:
 895         case PT_CONTINUE:
 896         case PT_TO_SCE:
 897         case PT_TO_SCX:
 898         case PT_SYSCALL:
 899         case PT_DETACH:
 900                 /* Zero means do not send any signal */
 901                 if (data < 0 || data > _SIG_MAXSIG) {
 902                         error = EINVAL;
 903                         break;
 904                 }
 905
 906                 switch (req) {
 907                 case PT_STEP:
 908                         CTR2(KTR_PTRACE, "PT_STEP: tid %d (pid %d)",
 909                             td2->td_tid, p->p_pid);
 910                         error = ptrace_single_step(td2);
 911                         if (error)
 912                                 goto out;
 913                         break;
 914                 case PT_CONTINUE:
 915                 case PT_TO_SCE:
 916                 case PT_TO_SCX:
 917                 case PT_SYSCALL:
 918                         if (addr != (void *)1) {
 919                                 error = ptrace_set_pc(td2,
 920                                     (u_long)(uintfptr_t)addr);
 921                                 if (error)
 922                                         goto out;
 923                         }
 924                         switch (req) {
 925                         case PT_TO_SCE:
 926                                 p->p_stops |= S_PT_SCE;
 927                                 CTR2(KTR_PTRACE,
 928                                     "PT_TO_SCE: pid %d, stops = %#x", p->p_pid,
 929                                     p->p_stops);
 930                                 break;
 931                         case PT_TO_SCX:
 932                                 p->p_stops |= S_PT_SCX;
 933                                 CTR2(KTR_PTRACE,
 934                                     "PT_TO_SCX: pid %d, stops = %#x", p->p_pid,
 935                                     p->p_stops);
 936                                 break;
 937                         case PT_SYSCALL:
 938                                 p->p_stops |= S_PT_SCE | S_PT_SCX;
 939                                 CTR2(KTR_PTRACE,
 940                                     "PT_SYSCALL: pid %d, stops = %#x", p->p_pid,
 941                                     p->p_stops);
 942                                 break;
 943                         case PT_CONTINUE:
 944                                 CTR1(KTR_PTRACE,
 945                                     "PT_CONTINUE: pid %d", p->p_pid);
 946                                 break;
 947                         }
 948                         break;
 949                 case PT_DETACH:
 950                         /* reset process parent */
 951                         if (p->p_oppid != p->p_pptr->p_pid) {
 952                                 PROC_LOCK(p->p_pptr);
 953                                 sigqueue_take(p->p_ksi);
 954                                 PROC_UNLOCK(p->p_pptr);
 955
 956                                 pp = proc_realparent(p);
 957                                 proc_reparent(p, pp);
 958                                 if (pp == initproc)
 959                                         p->p_sigparent = SIGCHLD;
 960                                 CTR2(KTR_PTRACE,
 961                                     "PT_DETACH: pid %d reparented to pid %d",
 962                                     p->p_pid, pp->p_pid);
 963                         } else
 964                                 CTR1(KTR_PTRACE, "PT_DETACH: pid %d", p->p_pid);
 965                         p->p_oppid = 0;
 966                         p->p_flag &= ~(P_TRACED | P_WAITED | P_FOLLOWFORK);
 967                         p->p_stops = 0;
 968
 969                         /* should we send SIGCHLD? */
 970                         /* childproc_continued(p); */
 971                         break;
 972                 }
 973
 974         sendsig:
 975                 if (proctree_locked) {
 976                         sx_xunlock(&proctree_lock);
 977                         proctree_locked = 0;
 978                 }
 979                 p->p_xsig = data;
 980                 p->p_xthread = NULL;
 981                 if ((p->p_flag & (P_STOPPED_SIG | P_STOPPED_TRACE)) != 0) {
 982                         /* deliver or queue signal */
 983                         td2->td_dbgflags &= ~TDB_XSIG;
 984                         td2->td_xsig = data;
 985
 986                         if (req == PT_DETACH) {
 987                                 FOREACH_THREAD_IN_PROC(p, td3)
 988                                         td3->td_dbgflags &= ~TDB_SUSPEND;
 989                         }
 990                         /*
 991                          * unsuspend all threads, to not let a thread run,
 992                          * you should use PT_SUSPEND to suspend it before
 993                          * continuing process.
 994                          */
 995                         PROC_SLOCK(p);
 996                         p->p_flag &= ~(P_STOPPED_TRACE|P_STOPPED_SIG|P_WAITED);
 997                         thread_unsuspend(p);
 998                         PROC_SUNLOCK(p);
 999                         if (req == PT_ATTACH)
1000                                 kern_psignal(p, data);
1001                 } else {
1002                         if (data)
1003                                 kern_psignal(p, data);
1004                 }
1005                 break;
1006
1007         case PT_WRITE_I:
1008         case PT_WRITE_D:
1009                 td2->td_dbgflags |= TDB_USERWR;
1010                 write = 1;
1011                 /* FALLTHROUGH */
1012         case PT_READ_I:
1013         case PT_READ_D:
1014                 PROC_UNLOCK(p);
1015                 tmp = 0;
1016                 /* write = 0 set above */
1017                 iov.iov_base = write ? (caddr_t)&data : (caddr_t)&tmp;
1018                 iov.iov_len = sizeof(int);
1019                 uio.uio_iov = &iov;
1020                 uio.uio_iovcnt = 1;
1021                 uio.uio_offset = (off_t)(uintptr_t)addr;
1022                 uio.uio_resid = sizeof(int);
1023                 uio.uio_segflg = UIO_SYSSPACE;  /* i.e.: the uap */
1024                 uio.uio_rw = write ? UIO_WRITE : UIO_READ;
1025                 uio.uio_td = td;
1026                 error = proc_rwmem(p, &uio);
1027                 if (uio.uio_resid != 0) {
1028                         /*
1029                          * XXX proc_rwmem() doesn't currently return ENOSPC,
1030                          * so I think write() can bogusly return 0.
1031                          * XXX what happens for short writes?  We don't want
1032                          * to write partial data.
1033                          * XXX proc_rwmem() returns EPERM for other invalid
1034                          * addresses.  Convert this to EINVAL.  Does this
1035                          * clobber returns of EPERM for other reasons?
1036                          */
1037                         if (error == 0 || error == ENOSPC || error == EPERM)
1038                                 error = EINVAL; /* EOF */
1039                 }
1040                 if (!write)
1041                         td->td_retval[0] = tmp;
1042                 if (error == 0) {
1043                         if (write)
1044                                 CTR3(KTR_PTRACE, "PT_WRITE: pid %d: %p <= %#x",
1045                                     p->p_pid, addr, data);
1046                         else
1047                                 CTR3(KTR_PTRACE, "PT_READ: pid %d: %p >= %#x",
1048                                     p->p_pid, addr, tmp);
1049                 }
1050                 PROC_LOCK(p);
1051                 break;
1052
1053         case PT_IO:
1054 #ifdef COMPAT_FREEBSD32
1055                 if (wrap32) {
1056                         piod32 = addr;
1057                         iov.iov_base = (void *)(uintptr_t)piod32->piod_addr;
1058                         iov.iov_len = piod32->piod_len;
1059                         uio.uio_offset = (off_t)(uintptr_t)piod32->piod_offs;
1060                         uio.uio_resid = piod32->piod_len;
1061                 } else
1062 #endif
1063                 {
1064                         piod = addr;
1065                         iov.iov_base = piod->piod_addr;
1066                         iov.iov_len = piod->piod_len;
1067                         uio.uio_offset = (off_t)(uintptr_t)piod->piod_offs;
1068                         uio.uio_resid = piod->piod_len;
1069                 }
1070                 uio.uio_iov = &iov;
1071                 uio.uio_iovcnt = 1;
1072                 uio.uio_segflg = UIO_USERSPACE;
1073                 uio.uio_td = td;
1074 #ifdef COMPAT_FREEBSD32
1075                 tmp = wrap32 ? piod32->piod_op : piod->piod_op;
1076 #else
1077                 tmp = piod->piod_op;
1078 #endif
1079                 switch (tmp) {
1080                 case PIOD_READ_D:
1081                 case PIOD_READ_I:
1082                         CTR3(KTR_PTRACE, "PT_IO: pid %d: READ (%p, %#x)",
1083                             p->p_pid, (uintptr_t)uio.uio_offset, uio.uio_resid);
1084                         uio.uio_rw = UIO_READ;
1085                         break;
1086                 case PIOD_WRITE_D:
1087                 case PIOD_WRITE_I:
1088                         CTR3(KTR_PTRACE, "PT_IO: pid %d: WRITE (%p, %#x)",
1089                             p->p_pid, (uintptr_t)uio.uio_offset, uio.uio_resid);
1090                         td2->td_dbgflags |= TDB_USERWR;
1091                         uio.uio_rw = UIO_WRITE;
1092                         break;
1093                 default:
1094                         error = EINVAL;
1095                         goto out;
1096                 }
1097                 PROC_UNLOCK(p);
1098                 error = proc_rwmem(p, &uio);
1099 #ifdef COMPAT_FREEBSD32
1100                 if (wrap32)
1101                         piod32->piod_len -= uio.uio_resid;
1102                 else
1103 #endif
1104                         piod->piod_len -= uio.uio_resid;
1105                 PROC_LOCK(p);
1106                 break;
1107
1108         case PT_KILL:
1109                 CTR1(KTR_PTRACE, "PT_KILL: pid %d", p->p_pid);
1110                 data = SIGKILL;
1111                 goto sendsig;   /* in PT_CONTINUE above */
1112
1113         case PT_SETREGS:
1114                 CTR2(KTR_PTRACE, "PT_SETREGS: tid %d (pid %d)", td2->td_tid,
1115                     p->p_pid);
1116                 td2->td_dbgflags |= TDB_USERWR;
1117                 error = PROC_WRITE(regs, td2, addr);
1118                 break;
1119
1120         case PT_GETREGS:
1121                 CTR2(KTR_PTRACE, "PT_GETREGS: tid %d (pid %d)", td2->td_tid,
1122                     p->p_pid);
1123                 error = PROC_READ(regs, td2, addr);
1124                 break;
1125
1126         case PT_SETFPREGS:
1127                 CTR2(KTR_PTRACE, "PT_SETFPREGS: tid %d (pid %d)", td2->td_tid,
1128                     p->p_pid);
1129                 td2->td_dbgflags |= TDB_USERWR;
1130                 error = PROC_WRITE(fpregs, td2, addr);
1131                 break;
1132
1133         case PT_GETFPREGS:
1134                 CTR2(KTR_PTRACE, "PT_GETFPREGS: tid %d (pid %d)", td2->td_tid,
1135                     p->p_pid);
1136                 error = PROC_READ(fpregs, td2, addr);
1137                 break;
1138
1139         case PT_SETDBREGS:
1140                 CTR2(KTR_PTRACE, "PT_SETDBREGS: tid %d (pid %d)", td2->td_tid,
1141                     p->p_pid);
1142                 td2->td_dbgflags |= TDB_USERWR;
1143                 error = PROC_WRITE(dbregs, td2, addr);
1144                 break;
1145
1146         case PT_GETDBREGS:
1147                 CTR2(KTR_PTRACE, "PT_GETDBREGS: tid %d (pid %d)", td2->td_tid,
1148                     p->p_pid);
1149                 error = PROC_READ(dbregs, td2, addr);
1150                 break;
1151
1152         case PT_LWPINFO:
1153                 if (data <= 0 ||
1154 #ifdef COMPAT_FREEBSD32
1155                     (!wrap32 && data > sizeof(*pl)) ||
1156                     (wrap32 && data > sizeof(*pl32))) {
1157 #else
1158                     data > sizeof(*pl)) {
1159 #endif
1160                         error = EINVAL;
1161                         break;
1162                 }
1163 #ifdef COMPAT_FREEBSD32
1164                 if (wrap32) {
1165                         pl = &plr;
1166                         pl32 = addr;
1167                 } else
1168 #endif
1169                 pl = addr;
1170                 pl->pl_lwpid = td2->td_tid;
1171                 pl->pl_event = PL_EVENT_NONE;
1172                 pl->pl_flags = 0;
1173                 if (td2->td_dbgflags & TDB_XSIG) {
1174                         pl->pl_event = PL_EVENT_SIGNAL;
1175                         if (td2->td_dbgksi.ksi_signo != 0 &&
1176 #ifdef COMPAT_FREEBSD32
1177                             ((!wrap32 && data >= offsetof(struct ptrace_lwpinfo,
1178                             pl_siginfo) + sizeof(pl->pl_siginfo)) ||
1179                             (wrap32 && data >= offsetof(struct ptrace_lwpinfo32,
1180                             pl_siginfo) + sizeof(struct siginfo32)))
1181 #else
1182                             data >= offsetof(struct ptrace_lwpinfo, pl_siginfo)
1183                             + sizeof(pl->pl_siginfo)
1184 #endif
1185                         ){
1186                                 pl->pl_flags |= PL_FLAG_SI;
1187                                 pl->pl_siginfo = td2->td_dbgksi.ksi_info;
1188                         }
1189                 }
1190                 if ((pl->pl_flags & PL_FLAG_SI) == 0)
1191                         bzero(&pl->pl_siginfo, sizeof(pl->pl_siginfo));
1192                 if (td2->td_dbgflags & TDB_SCE)
1193                         pl->pl_flags |= PL_FLAG_SCE;
1194                 else if (td2->td_dbgflags & TDB_SCX)
1195                         pl->pl_flags |= PL_FLAG_SCX;
1196                 if (td2->td_dbgflags & TDB_EXEC)
1197                         pl->pl_flags |= PL_FLAG_EXEC;
1198                 if (td2->td_dbgflags & TDB_FORK) {
1199                         pl->pl_flags |= PL_FLAG_FORKED;
1200                         pl->pl_child_pid = td2->td_dbg_forked;
1201                 }
1202                 if (td2->td_dbgflags & TDB_CHILD)
1203                         pl->pl_flags |= PL_FLAG_CHILD;
1204                 pl->pl_sigmask = td2->td_sigmask;
1205                 pl->pl_siglist = td2->td_siglist;
1206                 strcpy(pl->pl_tdname, td2->td_name);
1207 #ifdef COMPAT_FREEBSD32
1208                 if (wrap32)
1209                         ptrace_lwpinfo_to32(pl, pl32);
1210 #endif
1211                 CTR5(KTR_PTRACE,
1212             "PT_LWPINFO: tid %d (pid %d) event %d flags %#x child pid %d",
1213                     td2->td_tid, p->p_pid, pl->pl_event, pl->pl_flags,
1214                     pl->pl_child_pid);
1215                 break;
1216
1217         case PT_GETNUMLWPS:
1218                 CTR2(KTR_PTRACE, "PT_GETNUMLWPS: pid %d: %d threads", p->p_pid,
1219                     p->p_numthreads);
1220                 td->td_retval[0] = p->p_numthreads;
1221                 break;
1222
1223         case PT_GETLWPLIST:
1224                 CTR3(KTR_PTRACE, "PT_GETLWPLIST: pid %d: data %d, actual %d",
1225                     p->p_pid, data, p->p_numthreads);
1226                 if (data <= 0) {
1227                         error = EINVAL;
1228                         break;
1229                 }
1230                 num = imin(p->p_numthreads, data);
1231                 PROC_UNLOCK(p);
1232                 buf = malloc(num * sizeof(lwpid_t), M_TEMP, M_WAITOK);
1233                 tmp = 0;
1234                 PROC_LOCK(p);
1235                 FOREACH_THREAD_IN_PROC(p, td2) {
1236                         if (tmp >= num)
1237                                 break;
1238                         buf[tmp++] = td2->td_tid;
1239                 }
1240                 PROC_UNLOCK(p);
1241                 error = copyout(buf, addr, tmp * sizeof(lwpid_t));
1242                 free(buf, M_TEMP);
1243                 if (!error)
1244                         td->td_retval[0] = tmp;
1245                 PROC_LOCK(p);
1246                 break;
1247
1248         case PT_VM_TIMESTAMP:
1249                 CTR2(KTR_PTRACE, "PT_VM_TIMESTAMP: pid %d: timestamp %d",
1250                     p->p_pid, p->p_vmspace->vm_map.timestamp);
1251                 td->td_retval[0] = p->p_vmspace->vm_map.timestamp;
1252                 break;
1253
1254         case PT_VM_ENTRY:
1255                 PROC_UNLOCK(p);
1256 #ifdef COMPAT_FREEBSD32
1257                 if (wrap32)
1258                         error = ptrace_vm_entry32(td, p, addr);
1259                 else
1260 #endif
1261                 error = ptrace_vm_entry(td, p, addr);
1262                 PROC_LOCK(p);
1263                 break;
1264
1265         default:
1266 #ifdef __HAVE_PTRACE_MACHDEP
1267                 if (req >= PT_FIRSTMACH) {
1268                         PROC_UNLOCK(p);
1269                         error = cpu_ptrace(td2, req, addr, data);
1270                         PROC_LOCK(p);
1271                 } else
1272 #endif
1273                         /* Unknown request. */
1274                         error = EINVAL;
1275                 break;
1276         }
1277
1278 out:
1279         /* Drop our hold on this process now that the request has completed. */
1280         _PRELE(p);
1281 fail:
1282         PROC_UNLOCK(p);
1283         if (proctree_locked)
1284                 sx_xunlock(&proctree_lock);
1285         return (error);
1286 }
1287 #undef PROC_READ
1288 #undef PROC_WRITE
1289
1290 /*
1291  * Stop a process because of a debugging event;
1292  * stay stopped until p->p_step is cleared
1293  * (cleared by PIOCCONT in procfs).
1294  */
1295 void
1296 stopevent(struct proc *p, unsigned int event, unsigned int val)
1297 {
1298
1299         PROC_LOCK_ASSERT(p, MA_OWNED);
1300         p->p_step = 1;
1301         CTR3(KTR_PTRACE, "stopevent: pid %d event %u val %u", p->p_pid, event,
1302             val);
1303         do {
1304                 if (event != S_EXIT)
1305                         p->p_xsig = val;
1306                 p->p_xthread = NULL;
1307                 p->p_stype = event;     /* Which event caused the stop? */
1308                 wakeup(&p->p_stype);    /* Wake up any PIOCWAIT'ing procs */
1309                 msleep(&p->p_step, &p->p_mtx, PWAIT, "stopevent", 0);
1310         } while (p->p_step);
1311 }