sys/kern/sys_process.c

   1 /*-
   2  * SPDX-License-Identifier: BSD-4-Clause
   3  *
   4  * Copyright (c) 1994, Sean Eric Fagan
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. All advertising materials mentioning features or use of this software
  16  *    must display the following acknowledgement:
  17  *      This product includes software developed by Sean Eric Fagan.
  18  * 4. The name of the author may not be used to endorse or promote products
  19  *    derived from this software without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 #include <sys/cdefs.h>
  35 __FBSDID("$FreeBSD$");
  36
  37 #include <sys/param.h>
  38 #include <sys/systm.h>
  39 #include <sys/ktr.h>
  40 #include <sys/lock.h>
  41 #include <sys/mutex.h>
  42 #include <sys/syscallsubr.h>
  43 #include <sys/sysent.h>
  44 #include <sys/sysproto.h>
  45 #include <sys/pioctl.h>
  46 #include <sys/priv.h>
  47 #include <sys/proc.h>
  48 #include <sys/vnode.h>
  49 #include <sys/ptrace.h>
  50 #include <sys/rwlock.h>
  51 #include <sys/sx.h>
  52 #include <sys/malloc.h>
  53 #include <sys/signalvar.h>
  54
  55 #include <machine/reg.h>
  56
  57 #include <security/audit/audit.h>
  58
  59 #include <vm/vm.h>
  60 #include <vm/pmap.h>
  61 #include <vm/vm_extern.h>
  62 #include <vm/vm_map.h>
  63 #include <vm/vm_kern.h>
  64 #include <vm/vm_object.h>
  65 #include <vm/vm_page.h>
  66 #include <vm/vm_param.h>
  67
  68 #ifdef COMPAT_FREEBSD32
  69 #include <sys/procfs.h>
  70 #include <compat/freebsd32/freebsd32_signal.h>
  71
  72 struct ptrace_io_desc32 {
  73         int             piod_op;
  74         uint32_t        piod_offs;
  75         uint32_t        piod_addr;
  76         uint32_t        piod_len;
  77 };
  78
  79 struct ptrace_vm_entry32 {
  80         int             pve_entry;
  81         int             pve_timestamp;
  82         uint32_t        pve_start;
  83         uint32_t        pve_end;
  84         uint32_t        pve_offset;
  85         u_int           pve_prot;
  86         u_int           pve_pathlen;
  87         int32_t         pve_fileid;
  88         u_int           pve_fsid;
  89         uint32_t        pve_path;
  90 };
  91 #endif
  92
  93 /*
  94  * Functions implemented using PROC_ACTION():
  95  *
  96  * proc_read_regs(proc, regs)
  97  *      Get the current user-visible register set from the process
  98  *      and copy it into the regs structure (<machine/reg.h>).
  99  *      The process is stopped at the time read_regs is called.
 100  *
 101  * proc_write_regs(proc, regs)
 102  *      Update the current register set from the passed in regs
 103  *      structure.  Take care to avoid clobbering special CPU
 104  *      registers or privileged bits in the PSL.
 105  *      Depending on the architecture this may have fix-up work to do,
 106  *      especially if the IAR or PCW are modified.
 107  *      The process is stopped at the time write_regs is called.
 108  *
 109  * proc_read_fpregs, proc_write_fpregs
 110  *      deal with the floating point register set, otherwise as above.
 111  *
 112  * proc_read_dbregs, proc_write_dbregs
 113  *      deal with the processor debug register set, otherwise as above.
 114  *
 115  * proc_sstep(proc)
 116  *      Arrange for the process to trap after executing a single instruction.
 117  */
 118
 119 #define PROC_ACTION(action) do {                                        \
 120         int error;                                                      \
 121                                                                         \
 122         PROC_LOCK_ASSERT(td->td_proc, MA_OWNED);                        \
 123         if ((td->td_proc->p_flag & P_INMEM) == 0)                       \
 124                 error = EIO;                                            \
 125         else                                                            \
 126                 error = (action);                                       \
 127         return (error);                                                 \
 128 } while(0)
 129
 130 int
 131 proc_read_regs(struct thread *td, struct reg *regs)
 132 {
 133
 134         PROC_ACTION(fill_regs(td, regs));
 135 }
 136
 137 int
 138 proc_write_regs(struct thread *td, struct reg *regs)
 139 {
 140
 141         PROC_ACTION(set_regs(td, regs));
 142 }
 143
 144 int
 145 proc_read_dbregs(struct thread *td, struct dbreg *dbregs)
 146 {
 147
 148         PROC_ACTION(fill_dbregs(td, dbregs));
 149 }
 150
 151 int
 152 proc_write_dbregs(struct thread *td, struct dbreg *dbregs)
 153 {
 154
 155         PROC_ACTION(set_dbregs(td, dbregs));
 156 }
 157
 158 /*
 159  * Ptrace doesn't support fpregs at all, and there are no security holes
 160  * or translations for fpregs, so we can just copy them.
 161  */
 162 int
 163 proc_read_fpregs(struct thread *td, struct fpreg *fpregs)
 164 {
 165
 166         PROC_ACTION(fill_fpregs(td, fpregs));
 167 }
 168
 169 int
 170 proc_write_fpregs(struct thread *td, struct fpreg *fpregs)
 171 {
 172
 173         PROC_ACTION(set_fpregs(td, fpregs));
 174 }
 175
 176 #ifdef COMPAT_FREEBSD32
 177 /* For 32 bit binaries, we need to expose the 32 bit regs layouts. */
 178 int
 179 proc_read_regs32(struct thread *td, struct reg32 *regs32)
 180 {
 181
 182         PROC_ACTION(fill_regs32(td, regs32));
 183 }
 184
 185 int
 186 proc_write_regs32(struct thread *td, struct reg32 *regs32)
 187 {
 188
 189         PROC_ACTION(set_regs32(td, regs32));
 190 }
 191
 192 int
 193 proc_read_dbregs32(struct thread *td, struct dbreg32 *dbregs32)
 194 {
 195
 196         PROC_ACTION(fill_dbregs32(td, dbregs32));
 197 }
 198
 199 int
 200 proc_write_dbregs32(struct thread *td, struct dbreg32 *dbregs32)
 201 {
 202
 203         PROC_ACTION(set_dbregs32(td, dbregs32));
 204 }
 205
 206 int
 207 proc_read_fpregs32(struct thread *td, struct fpreg32 *fpregs32)
 208 {
 209
 210         PROC_ACTION(fill_fpregs32(td, fpregs32));
 211 }
 212
 213 int
 214 proc_write_fpregs32(struct thread *td, struct fpreg32 *fpregs32)
 215 {
 216
 217         PROC_ACTION(set_fpregs32(td, fpregs32));
 218 }
 219 #endif
 220
 221 int
 222 proc_sstep(struct thread *td)
 223 {
 224
 225         PROC_ACTION(ptrace_single_step(td));
 226 }
 227
 228 int
 229 proc_rwmem(struct proc *p, struct uio *uio)
 230 {
 231         vm_map_t map;
 232         vm_offset_t pageno;             /* page number */
 233         vm_prot_t reqprot;
 234         int error, fault_flags, page_offset, writing;
 235
 236         /*
 237          * Assert that someone has locked this vmspace.  (Should be
 238          * curthread but we can't assert that.)  This keeps the process
 239          * from exiting out from under us until this operation completes.
 240          */
 241         PROC_ASSERT_HELD(p);
 242         PROC_LOCK_ASSERT(p, MA_NOTOWNED);
 243
 244         /*
 245          * The map we want...
 246          */
 247         map = &p->p_vmspace->vm_map;
 248
 249         /*
 250          * If we are writing, then we request vm_fault() to create a private
 251          * copy of each page.  Since these copies will not be writeable by the
 252          * process, we must explicity request that they be dirtied.
 253          */
 254         writing = uio->uio_rw == UIO_WRITE;
 255         reqprot = writing ? VM_PROT_COPY | VM_PROT_READ : VM_PROT_READ;
 256         fault_flags = writing ? VM_FAULT_DIRTY : VM_FAULT_NORMAL;
 257
 258         /*
 259          * Only map in one page at a time.  We don't have to, but it
 260          * makes things easier.  This way is trivial - right?
 261          */
 262         do {
 263                 vm_offset_t uva;
 264                 u_int len;
 265                 vm_page_t m;
 266
 267                 uva = (vm_offset_t)uio->uio_offset;
 268
 269                 /*
 270                  * Get the page number of this segment.
 271                  */
 272                 pageno = trunc_page(uva);
 273                 page_offset = uva - pageno;
 274
 275                 /*
 276                  * How many bytes to copy
 277                  */
 278                 len = min(PAGE_SIZE - page_offset, uio->uio_resid);
 279
 280                 /*
 281                  * Fault and hold the page on behalf of the process.
 282                  */
 283                 error = vm_fault_hold(map, pageno, reqprot, fault_flags, &m);
 284                 if (error != KERN_SUCCESS) {
 285                         if (error == KERN_RESOURCE_SHORTAGE)
 286                                 error = ENOMEM;
 287                         else
 288                                 error = EFAULT;
 289                         break;
 290                 }
 291
 292                 /*
 293                  * Now do the i/o move.
 294                  */
 295                 error = uiomove_fromphys(&m, page_offset, len, uio);
 296
 297                 /* Make the I-cache coherent for breakpoints. */
 298                 if (writing && error == 0) {
 299                         vm_map_lock_read(map);
 300                         if (vm_map_check_protection(map, pageno, pageno +
 301                             PAGE_SIZE, VM_PROT_EXECUTE))
 302                                 vm_sync_icache(map, uva, len);
 303                         vm_map_unlock_read(map);
 304                 }
 305
 306                 /*
 307                  * Release the page.
 308                  */
 309                 vm_page_lock(m);
 310                 if (vm_page_unwire(m, PQ_ACTIVE) && m->object == NULL)
 311                         vm_page_free(m);
 312                 vm_page_unlock(m);
 313
 314         } while (error == 0 && uio->uio_resid > 0);
 315
 316         return (error);
 317 }
 318
 319 static ssize_t
 320 proc_iop(struct thread *td, struct proc *p, vm_offset_t va, void *buf,
 321     size_t len, enum uio_rw rw)
 322 {
 323         struct iovec iov;
 324         struct uio uio;
 325         ssize_t slen;
 326
 327         MPASS(len < SSIZE_MAX);
 328         slen = (ssize_t)len;
 329
 330         iov.iov_base = (caddr_t)buf;
 331         iov.iov_len = len;
 332         uio.uio_iov = &iov;
 333         uio.uio_iovcnt = 1;
 334         uio.uio_offset = va;
 335         uio.uio_resid = slen;
 336         uio.uio_segflg = UIO_SYSSPACE;
 337         uio.uio_rw = rw;
 338         uio.uio_td = td;
 339         proc_rwmem(p, &uio);
 340         if (uio.uio_resid == slen)
 341                 return (-1);
 342         return (slen - uio.uio_resid);
 343 }
 344
 345 ssize_t
 346 proc_readmem(struct thread *td, struct proc *p, vm_offset_t va, void *buf,
 347     size_t len)
 348 {
 349
 350         return (proc_iop(td, p, va, buf, len, UIO_READ));
 351 }
 352
 353 ssize_t
 354 proc_writemem(struct thread *td, struct proc *p, vm_offset_t va, void *buf,
 355     size_t len)
 356 {
 357
 358         return (proc_iop(td, p, va, buf, len, UIO_WRITE));
 359 }
 360
 361 static int
 362 ptrace_vm_entry(struct thread *td, struct proc *p, struct ptrace_vm_entry *pve)
 363 {
 364         struct vattr vattr;
 365         vm_map_t map;
 366         vm_map_entry_t entry;
 367         vm_object_t obj, tobj, lobj;
 368         struct vmspace *vm;
 369         struct vnode *vp;
 370         char *freepath, *fullpath;
 371         u_int pathlen;
 372         int error, index;
 373
 374         error = 0;
 375         obj = NULL;
 376
 377         vm = vmspace_acquire_ref(p);
 378         map = &vm->vm_map;
 379         vm_map_lock_read(map);
 380
 381         do {
 382                 entry = map->header.next;
 383                 index = 0;
 384                 while (index < pve->pve_entry && entry != &map->header) {
 385                         entry = entry->next;
 386                         index++;
 387                 }
 388                 if (index != pve->pve_entry) {
 389                         error = EINVAL;
 390                         break;
 391                 }
 392                 KASSERT((map->header.eflags & MAP_ENTRY_IS_SUB_MAP) == 0,
 393                     ("Submap in map header"));
 394                 while ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) != 0) {
 395                         entry = entry->next;
 396                         index++;
 397                 }
 398                 if (entry == &map->header) {
 399                         error = ENOENT;
 400                         break;
 401                 }
 402
 403                 /* We got an entry. */
 404                 pve->pve_entry = index + 1;
 405                 pve->pve_timestamp = map->timestamp;
 406                 pve->pve_start = entry->start;
 407                 pve->pve_end = entry->end - 1;
 408                 pve->pve_offset = entry->offset;
 409                 pve->pve_prot = entry->protection;
 410
 411                 /* Backing object's path needed? */
 412                 if (pve->pve_pathlen == 0)
 413                         break;
 414
 415                 pathlen = pve->pve_pathlen;
 416                 pve->pve_pathlen = 0;
 417
 418                 obj = entry->object.vm_object;
 419                 if (obj != NULL)
 420                         VM_OBJECT_RLOCK(obj);
 421         } while (0);
 422
 423         vm_map_unlock_read(map);
 424
 425         pve->pve_fsid = VNOVAL;
 426         pve->pve_fileid = VNOVAL;
 427
 428         if (error == 0 && obj != NULL) {
 429                 lobj = obj;
 430                 for (tobj = obj; tobj != NULL; tobj = tobj->backing_object) {
 431                         if (tobj != obj)
 432                                 VM_OBJECT_RLOCK(tobj);
 433                         if (lobj != obj)
 434                                 VM_OBJECT_RUNLOCK(lobj);
 435                         lobj = tobj;
 436                         pve->pve_offset += tobj->backing_object_offset;
 437                 }
 438                 vp = vm_object_vnode(lobj);
 439                 if (vp != NULL)
 440                         vref(vp);
 441                 if (lobj != obj)
 442                         VM_OBJECT_RUNLOCK(lobj);
 443                 VM_OBJECT_RUNLOCK(obj);
 444
 445                 if (vp != NULL) {
 446                         freepath = NULL;
 447                         fullpath = NULL;
 448                         vn_fullpath(td, vp, &fullpath, &freepath);
 449                         vn_lock(vp, LK_SHARED | LK_RETRY);
 450                         if (VOP_GETATTR(vp, &vattr, td->td_ucred) == 0) {
 451                                 pve->pve_fileid = vattr.va_fileid;
 452                                 pve->pve_fsid = vattr.va_fsid;
 453                         }
 454                         vput(vp);
 455
 456                         if (fullpath != NULL) {
 457                                 pve->pve_pathlen = strlen(fullpath) + 1;
 458                                 if (pve->pve_pathlen <= pathlen) {
 459                                         error = copyout(fullpath, pve->pve_path,
 460                                             pve->pve_pathlen);
 461                                 } else
 462                                         error = ENAMETOOLONG;
 463                         }
 464                         if (freepath != NULL)
 465                                 free(freepath, M_TEMP);
 466                 }
 467         }
 468         vmspace_free(vm);
 469         if (error == 0)
 470                 CTR3(KTR_PTRACE, "PT_VM_ENTRY: pid %d, entry %d, start %p",
 471                     p->p_pid, pve->pve_entry, pve->pve_start);
 472
 473         return (error);
 474 }
 475
 476 #ifdef COMPAT_FREEBSD32
 477 static int
 478 ptrace_vm_entry32(struct thread *td, struct proc *p,
 479     struct ptrace_vm_entry32 *pve32)
 480 {
 481         struct ptrace_vm_entry pve;
 482         int error;
 483
 484         pve.pve_entry = pve32->pve_entry;
 485         pve.pve_pathlen = pve32->pve_pathlen;
 486         pve.pve_path = (void *)(uintptr_t)pve32->pve_path;
 487
 488         error = ptrace_vm_entry(td, p, &pve);
 489         if (error == 0) {
 490                 pve32->pve_entry = pve.pve_entry;
 491                 pve32->pve_timestamp = pve.pve_timestamp;
 492                 pve32->pve_start = pve.pve_start;
 493                 pve32->pve_end = pve.pve_end;
 494                 pve32->pve_offset = pve.pve_offset;
 495                 pve32->pve_prot = pve.pve_prot;
 496                 pve32->pve_fileid = pve.pve_fileid;
 497                 pve32->pve_fsid = pve.pve_fsid;
 498         }
 499
 500         pve32->pve_pathlen = pve.pve_pathlen;
 501         return (error);
 502 }
 503
 504 static void
 505 ptrace_lwpinfo_to32(const struct ptrace_lwpinfo *pl,
 506     struct ptrace_lwpinfo32 *pl32)
 507 {
 508
 509         bzero(pl32, sizeof(*pl32));
 510         pl32->pl_lwpid = pl->pl_lwpid;
 511         pl32->pl_event = pl->pl_event;
 512         pl32->pl_flags = pl->pl_flags;
 513         pl32->pl_sigmask = pl->pl_sigmask;
 514         pl32->pl_siglist = pl->pl_siglist;
 515         siginfo_to_siginfo32(&pl->pl_siginfo, &pl32->pl_siginfo);
 516         strcpy(pl32->pl_tdname, pl->pl_tdname);
 517         pl32->pl_child_pid = pl->pl_child_pid;
 518         pl32->pl_syscall_code = pl->pl_syscall_code;
 519         pl32->pl_syscall_narg = pl->pl_syscall_narg;
 520 }
 521 #endif /* COMPAT_FREEBSD32 */
 522
 523 /*
 524  * Process debugging system call.
 525  */
 526 #ifndef _SYS_SYSPROTO_H_
 527 struct ptrace_args {
 528         int     req;
 529         pid_t   pid;
 530         caddr_t addr;
 531         int     data;
 532 };
 533 #endif
 534
 535 #ifdef COMPAT_FREEBSD32
 536 /*
 537  * This CPP subterfuge is to try and reduce the number of ifdefs in
 538  * the body of the code.
 539  *   COPYIN(uap->addr, &r.reg, sizeof r.reg);
 540  * becomes either:
 541  *   copyin(uap->addr, &r.reg, sizeof r.reg);
 542  * or
 543  *   copyin(uap->addr, &r.reg32, sizeof r.reg32);
 544  * .. except this is done at runtime.
 545  */
 546 #define BZERO(a, s)             wrap32 ? \
 547         bzero(a ## 32, s ## 32) : \
 548         bzero(a, s)
 549 #define COPYIN(u, k, s)         wrap32 ? \
 550         copyin(u, k ## 32, s ## 32) : \
 551         copyin(u, k, s)
 552 #define COPYOUT(k, u, s)        wrap32 ? \
 553         copyout(k ## 32, u, s ## 32) : \
 554         copyout(k, u, s)
 555 #else
 556 #define BZERO(a, s)             bzero(a, s)
 557 #define COPYIN(u, k, s)         copyin(u, k, s)
 558 #define COPYOUT(k, u, s)        copyout(k, u, s)
 559 #endif
 560 int
 561 sys_ptrace(struct thread *td, struct ptrace_args *uap)
 562 {
 563         /*
 564          * XXX this obfuscation is to reduce stack usage, but the register
 565          * structs may be too large to put on the stack anyway.
 566          */
 567         union {
 568                 struct ptrace_io_desc piod;
 569                 struct ptrace_lwpinfo pl;
 570                 struct ptrace_vm_entry pve;
 571                 struct dbreg dbreg;
 572                 struct fpreg fpreg;
 573                 struct reg reg;
 574 #ifdef COMPAT_FREEBSD32
 575                 struct dbreg32 dbreg32;
 576                 struct fpreg32 fpreg32;
 577                 struct reg32 reg32;
 578                 struct ptrace_io_desc32 piod32;
 579                 struct ptrace_lwpinfo32 pl32;
 580                 struct ptrace_vm_entry32 pve32;
 581 #endif
 582                 char args[sizeof(td->td_sa.args)];
 583                 int ptevents;
 584         } r;
 585         void *addr;
 586         int error = 0;
 587 #ifdef COMPAT_FREEBSD32
 588         int wrap32 = 0;
 589
 590         if (SV_CURPROC_FLAG(SV_ILP32))
 591                 wrap32 = 1;
 592 #endif
 593         AUDIT_ARG_PID(uap->pid);
 594         AUDIT_ARG_CMD(uap->req);
 595         AUDIT_ARG_VALUE(uap->data);
 596         addr = &r;
 597         switch (uap->req) {
 598         case PT_GET_EVENT_MASK:
 599         case PT_LWPINFO:
 600         case PT_GET_SC_ARGS:
 601                 break;
 602         case PT_GETREGS:
 603                 BZERO(&r.reg, sizeof r.reg);
 604                 break;
 605         case PT_GETFPREGS:
 606                 BZERO(&r.fpreg, sizeof r.fpreg);
 607                 break;
 608         case PT_GETDBREGS:
 609                 BZERO(&r.dbreg, sizeof r.dbreg);
 610                 break;
 611         case PT_SETREGS:
 612                 error = COPYIN(uap->addr, &r.reg, sizeof r.reg);
 613                 break;
 614         case PT_SETFPREGS:
 615                 error = COPYIN(uap->addr, &r.fpreg, sizeof r.fpreg);
 616                 break;
 617         case PT_SETDBREGS:
 618                 error = COPYIN(uap->addr, &r.dbreg, sizeof r.dbreg);
 619                 break;
 620         case PT_SET_EVENT_MASK:
 621                 if (uap->data != sizeof(r.ptevents))
 622                         error = EINVAL;
 623                 else
 624                         error = copyin(uap->addr, &r.ptevents, uap->data);
 625                 break;
 626         case PT_IO:
 627                 error = COPYIN(uap->addr, &r.piod, sizeof r.piod);
 628                 break;
 629         case PT_VM_ENTRY:
 630                 error = COPYIN(uap->addr, &r.pve, sizeof r.pve);
 631                 break;
 632         default:
 633                 addr = uap->addr;
 634                 break;
 635         }
 636         if (error)
 637                 return (error);
 638
 639         error = kern_ptrace(td, uap->req, uap->pid, addr, uap->data);
 640         if (error)
 641                 return (error);
 642
 643         switch (uap->req) {
 644         case PT_VM_ENTRY:
 645                 error = COPYOUT(&r.pve, uap->addr, sizeof r.pve);
 646                 break;
 647         case PT_IO:
 648                 error = COPYOUT(&r.piod, uap->addr, sizeof r.piod);
 649                 break;
 650         case PT_GETREGS:
 651                 error = COPYOUT(&r.reg, uap->addr, sizeof r.reg);
 652                 break;
 653         case PT_GETFPREGS:
 654                 error = COPYOUT(&r.fpreg, uap->addr, sizeof r.fpreg);
 655                 break;
 656         case PT_GETDBREGS:
 657                 error = COPYOUT(&r.dbreg, uap->addr, sizeof r.dbreg);
 658                 break;
 659         case PT_GET_EVENT_MASK:
 660                 /* NB: The size in uap->data is validated in kern_ptrace(). */
 661                 error = copyout(&r.ptevents, uap->addr, uap->data);
 662                 break;
 663         case PT_LWPINFO:
 664                 /* NB: The size in uap->data is validated in kern_ptrace(). */
 665                 error = copyout(&r.pl, uap->addr, uap->data);
 666                 break;
 667         case PT_GET_SC_ARGS:
 668                 error = copyout(r.args, uap->addr, MIN(uap->data,
 669                     sizeof(r.args)));
 670                 break;
 671         }
 672
 673         return (error);
 674 }
 675 #undef COPYIN
 676 #undef COPYOUT
 677 #undef BZERO
 678
 679 #ifdef COMPAT_FREEBSD32
 680 /*
 681  *   PROC_READ(regs, td2, addr);
 682  * becomes either:
 683  *   proc_read_regs(td2, addr);
 684  * or
 685  *   proc_read_regs32(td2, addr);
 686  * .. except this is done at runtime.  There is an additional
 687  * complication in that PROC_WRITE disallows 32 bit consumers
 688  * from writing to 64 bit address space targets.
 689  */
 690 #define PROC_READ(w, t, a)      wrap32 ? \
 691         proc_read_ ## w ## 32(t, a) : \
 692         proc_read_ ## w (t, a)
 693 #define PROC_WRITE(w, t, a)     wrap32 ? \
 694         (safe ? proc_write_ ## w ## 32(t, a) : EINVAL ) : \
 695         proc_write_ ## w (t, a)
 696 #else
 697 #define PROC_READ(w, t, a)      proc_read_ ## w (t, a)
 698 #define PROC_WRITE(w, t, a)     proc_write_ ## w (t, a)
 699 #endif
 700
 701 void
 702 proc_set_traced(struct proc *p, bool stop)
 703 {
 704
 705         sx_assert(&proctree_lock, SX_XLOCKED);
 706         PROC_LOCK_ASSERT(p, MA_OWNED);
 707         p->p_flag |= P_TRACED;
 708         if (stop)
 709                 p->p_flag2 |= P2_PTRACE_FSTP;
 710         p->p_ptevents = PTRACE_DEFAULT;
 711 }
 712
 713 int
 714 kern_ptrace(struct thread *td, int req, pid_t pid, void *addr, int data)
 715 {
 716         struct iovec iov;
 717         struct uio uio;
 718         struct proc *curp, *p, *pp;
 719         struct thread *td2 = NULL, *td3;
 720         struct ptrace_io_desc *piod = NULL;
 721         struct ptrace_lwpinfo *pl;
 722         int error, num, tmp;
 723         int proctree_locked = 0;
 724         lwpid_t tid = 0, *buf;
 725 #ifdef COMPAT_FREEBSD32
 726         int wrap32 = 0, safe = 0;
 727         struct ptrace_io_desc32 *piod32 = NULL;
 728         struct ptrace_lwpinfo32 *pl32 = NULL;
 729         struct ptrace_lwpinfo plr;
 730 #endif
 731
 732         curp = td->td_proc;
 733
 734         /* Lock proctree before locking the process. */
 735         switch (req) {
 736         case PT_TRACE_ME:
 737         case PT_ATTACH:
 738         case PT_STEP:
 739         case PT_CONTINUE:
 740         case PT_TO_SCE:
 741         case PT_TO_SCX:
 742         case PT_SYSCALL:
 743         case PT_FOLLOW_FORK:
 744         case PT_LWP_EVENTS:
 745         case PT_GET_EVENT_MASK:
 746         case PT_SET_EVENT_MASK:
 747         case PT_DETACH:
 748         case PT_GET_SC_ARGS:
 749                 sx_xlock(&proctree_lock);
 750                 proctree_locked = 1;
 751                 break;
 752         default:
 753                 break;
 754         }
 755
 756         if (req == PT_TRACE_ME) {
 757                 p = td->td_proc;
 758                 PROC_LOCK(p);
 759         } else {
 760                 if (pid <= PID_MAX) {
 761                         if ((p = pfind(pid)) == NULL) {
 762                                 if (proctree_locked)
 763                                         sx_xunlock(&proctree_lock);
 764                                 return (ESRCH);
 765                         }
 766                 } else {
 767                         td2 = tdfind(pid, -1);
 768                         if (td2 == NULL) {
 769                                 if (proctree_locked)
 770                                         sx_xunlock(&proctree_lock);
 771                                 return (ESRCH);
 772                         }
 773                         p = td2->td_proc;
 774                         tid = pid;
 775                         pid = p->p_pid;
 776                 }
 777         }
 778         AUDIT_ARG_PROCESS(p);
 779
 780         if ((p->p_flag & P_WEXIT) != 0) {
 781                 error = ESRCH;
 782                 goto fail;
 783         }
 784         if ((error = p_cansee(td, p)) != 0)
 785                 goto fail;
 786
 787         if ((error = p_candebug(td, p)) != 0)
 788                 goto fail;
 789
 790         /*
 791          * System processes can't be debugged.
 792          */
 793         if ((p->p_flag & P_SYSTEM) != 0) {
 794                 error = EINVAL;
 795                 goto fail;
 796         }
 797
 798         if (tid == 0) {
 799                 if ((p->p_flag & P_STOPPED_TRACE) != 0) {
 800                         KASSERT(p->p_xthread != NULL, ("NULL p_xthread"));
 801                         td2 = p->p_xthread;
 802                 } else {
 803                         td2 = FIRST_THREAD_IN_PROC(p);
 804                 }
 805                 tid = td2->td_tid;
 806         }
 807
 808 #ifdef COMPAT_FREEBSD32
 809         /*
 810          * Test if we're a 32 bit client and what the target is.
 811          * Set the wrap controls accordingly.
 812          */
 813         if (SV_CURPROC_FLAG(SV_ILP32)) {
 814                 if (SV_PROC_FLAG(td2->td_proc, SV_ILP32))
 815                         safe = 1;
 816                 wrap32 = 1;
 817         }
 818 #endif
 819         /*
 820          * Permissions check
 821          */
 822         switch (req) {
 823         case PT_TRACE_ME:
 824                 /*
 825                  * Always legal, when there is a parent process which
 826                  * could trace us.  Otherwise, reject.
 827                  */
 828                 if ((p->p_flag & P_TRACED) != 0) {
 829                         error = EBUSY;
 830                         goto fail;
 831                 }
 832                 if (p->p_pptr == initproc) {
 833                         error = EPERM;
 834                         goto fail;
 835                 }
 836                 break;
 837
 838         case PT_ATTACH:
 839                 /* Self */
 840                 if (p == td->td_proc) {
 841                         error = EINVAL;
 842                         goto fail;
 843                 }
 844
 845                 /* Already traced */
 846                 if (p->p_flag & P_TRACED) {
 847                         error = EBUSY;
 848                         goto fail;
 849                 }
 850
 851                 /* Can't trace an ancestor if you're being traced. */
 852                 if (curp->p_flag & P_TRACED) {
 853                         for (pp = curp->p_pptr; pp != NULL; pp = pp->p_pptr) {
 854                                 if (pp == p) {
 855                                         error = EINVAL;
 856                                         goto fail;
 857                                 }
 858                         }
 859                 }
 860
 861
 862                 /* OK */
 863                 break;
 864
 865         case PT_CLEARSTEP:
 866                 /* Allow thread to clear single step for itself */
 867                 if (td->td_tid == tid)
 868                         break;
 869
 870                 /* FALLTHROUGH */
 871         default:
 872                 /* not being traced... */
 873                 if ((p->p_flag & P_TRACED) == 0) {
 874                         error = EPERM;
 875                         goto fail;
 876                 }
 877
 878                 /* not being traced by YOU */
 879                 if (p->p_pptr != td->td_proc) {
 880                         error = EBUSY;
 881                         goto fail;
 882                 }
 883
 884                 /* not currently stopped */
 885                 if ((p->p_flag & P_STOPPED_TRACE) == 0 ||
 886                     p->p_suspcount != p->p_numthreads  ||
 887                     (p->p_flag & P_WAITED) == 0) {
 888                         error = EBUSY;
 889                         goto fail;
 890                 }
 891
 892                 /* OK */
 893                 break;
 894         }
 895
 896         /* Keep this process around until we finish this request. */
 897         _PHOLD(p);
 898
 899 #ifdef FIX_SSTEP
 900         /*
 901          * Single step fixup ala procfs
 902          */
 903         FIX_SSTEP(td2);
 904 #endif
 905
 906         /*
 907          * Actually do the requests
 908          */
 909
 910         td->td_retval[0] = 0;
 911
 912         switch (req) {
 913         case PT_TRACE_ME:
 914                 /* set my trace flag and "owner" so it can read/write me */
 915                 proc_set_traced(p, false);
 916                 if (p->p_flag & P_PPWAIT)
 917                         p->p_flag |= P_PPTRACE;
 918                 CTR1(KTR_PTRACE, "PT_TRACE_ME: pid %d", p->p_pid);
 919                 break;
 920
 921         case PT_ATTACH:
 922                 /* security check done above */
 923                 /*
 924                  * It would be nice if the tracing relationship was separate
 925                  * from the parent relationship but that would require
 926                  * another set of links in the proc struct or for "wait"
 927                  * to scan the entire proc table.  To make life easier,
 928                  * we just re-parent the process we're trying to trace.
 929                  * The old parent is remembered so we can put things back
 930                  * on a "detach".
 931                  */
 932                 proc_set_traced(p, true);
 933                 if (p->p_pptr != td->td_proc) {
 934                         proc_reparent(p, td->td_proc, false);
 935                 }
 936                 CTR2(KTR_PTRACE, "PT_ATTACH: pid %d, oppid %d", p->p_pid,
 937                     p->p_oppid);
 938
 939                 sx_xunlock(&proctree_lock);
 940                 proctree_locked = 0;
 941                 MPASS(p->p_xthread == NULL);
 942                 MPASS((p->p_flag & P_STOPPED_TRACE) == 0);
 943
 944                 /*
 945                  * If already stopped due to a stop signal, clear the
 946                  * existing stop before triggering a traced SIGSTOP.
 947                  */
 948                 if ((p->p_flag & P_STOPPED_SIG) != 0) {
 949                         PROC_SLOCK(p);
 950                         p->p_flag &= ~(P_STOPPED_SIG | P_WAITED);
 951                         thread_unsuspend(p);
 952                         PROC_SUNLOCK(p);
 953                 }
 954
 955                 kern_psignal(p, SIGSTOP);
 956                 break;
 957
 958         case PT_CLEARSTEP:
 959                 CTR2(KTR_PTRACE, "PT_CLEARSTEP: tid %d (pid %d)", td2->td_tid,
 960                     p->p_pid);
 961                 error = ptrace_clear_single_step(td2);
 962                 break;
 963
 964         case PT_SETSTEP:
 965                 CTR2(KTR_PTRACE, "PT_SETSTEP: tid %d (pid %d)", td2->td_tid,
 966                     p->p_pid);
 967                 error = ptrace_single_step(td2);
 968                 break;
 969
 970         case PT_SUSPEND:
 971                 CTR2(KTR_PTRACE, "PT_SUSPEND: tid %d (pid %d)", td2->td_tid,
 972                     p->p_pid);
 973                 td2->td_dbgflags |= TDB_SUSPEND;
 974                 thread_lock(td2);
 975                 td2->td_flags |= TDF_NEEDSUSPCHK;
 976                 thread_unlock(td2);
 977                 break;
 978
 979         case PT_RESUME:
 980                 CTR2(KTR_PTRACE, "PT_RESUME: tid %d (pid %d)", td2->td_tid,
 981                     p->p_pid);
 982                 td2->td_dbgflags &= ~TDB_SUSPEND;
 983                 break;
 984
 985         case PT_FOLLOW_FORK:
 986                 CTR3(KTR_PTRACE, "PT_FOLLOW_FORK: pid %d %s -> %s", p->p_pid,
 987                     p->p_ptevents & PTRACE_FORK ? "enabled" : "disabled",
 988                     data ? "enabled" : "disabled");
 989                 if (data)
 990                         p->p_ptevents |= PTRACE_FORK;
 991                 else
 992                         p->p_ptevents &= ~PTRACE_FORK;
 993                 break;
 994
 995         case PT_LWP_EVENTS:
 996                 CTR3(KTR_PTRACE, "PT_LWP_EVENTS: pid %d %s -> %s", p->p_pid,
 997                     p->p_ptevents & PTRACE_LWP ? "enabled" : "disabled",
 998                     data ? "enabled" : "disabled");
 999                 if (data)
1000                         p->p_ptevents |= PTRACE_LWP;
1001                 else
1002                         p->p_ptevents &= ~PTRACE_LWP;
1003                 break;
1004
1005         case PT_GET_EVENT_MASK:
1006                 if (data != sizeof(p->p_ptevents)) {
1007                         error = EINVAL;
1008                         break;
1009                 }
1010                 CTR2(KTR_PTRACE, "PT_GET_EVENT_MASK: pid %d mask %#x", p->p_pid,
1011                     p->p_ptevents);
1012                 *(int *)addr = p->p_ptevents;
1013                 break;
1014
1015         case PT_SET_EVENT_MASK:
1016                 if (data != sizeof(p->p_ptevents)) {
1017                         error = EINVAL;
1018                         break;
1019                 }
1020                 tmp = *(int *)addr;
1021                 if ((tmp & ~(PTRACE_EXEC | PTRACE_SCE | PTRACE_SCX |
1022                     PTRACE_FORK | PTRACE_LWP | PTRACE_VFORK)) != 0) {
1023                         error = EINVAL;
1024                         break;
1025                 }
1026                 CTR3(KTR_PTRACE, "PT_SET_EVENT_MASK: pid %d mask %#x -> %#x",
1027                     p->p_pid, p->p_ptevents, tmp);
1028                 p->p_ptevents = tmp;
1029                 break;
1030
1031         case PT_GET_SC_ARGS:
1032                 CTR1(KTR_PTRACE, "PT_GET_SC_ARGS: pid %d", p->p_pid);
1033                 if ((td2->td_dbgflags & (TDB_SCE | TDB_SCX)) == 0
1034 #ifdef COMPAT_FREEBSD32
1035                     || (wrap32 && !safe)
1036 #endif
1037                     ) {
1038                         error = EINVAL;
1039                         break;
1040                 }
1041                 bzero(addr, sizeof(td2->td_sa.args));
1042 #ifdef COMPAT_FREEBSD32
1043                 if (wrap32)
1044                         for (num = 0; num < nitems(td2->td_sa.args); num++)
1045                                 ((uint32_t *)addr)[num] = (uint32_t)
1046                                     td2->td_sa.args[num];
1047                 else
1048 #endif
1049                         bcopy(td2->td_sa.args, addr, td2->td_sa.narg *
1050                             sizeof(register_t));
1051                 break;
1052
1053         case PT_STEP:
1054         case PT_CONTINUE:
1055         case PT_TO_SCE:
1056         case PT_TO_SCX:
1057         case PT_SYSCALL:
1058         case PT_DETACH:
1059                 /* Zero means do not send any signal */
1060                 if (data < 0 || data > _SIG_MAXSIG) {
1061                         error = EINVAL;
1062                         break;
1063                 }
1064
1065                 switch (req) {
1066                 case PT_STEP:
1067                         CTR3(KTR_PTRACE, "PT_STEP: tid %d (pid %d), sig = %d",
1068                             td2->td_tid, p->p_pid, data);
1069                         error = ptrace_single_step(td2);
1070                         if (error)
1071                                 goto out;
1072                         break;
1073                 case PT_CONTINUE:
1074                 case PT_TO_SCE:
1075                 case PT_TO_SCX:
1076                 case PT_SYSCALL:
1077                         if (addr != (void *)1) {
1078                                 error = ptrace_set_pc(td2,
1079                                     (u_long)(uintfptr_t)addr);
1080                                 if (error)
1081                                         goto out;
1082                         }
1083                         switch (req) {
1084                         case PT_TO_SCE:
1085                                 p->p_ptevents |= PTRACE_SCE;
1086                                 CTR4(KTR_PTRACE,
1087                     "PT_TO_SCE: pid %d, events = %#x, PC = %#lx, sig = %d",
1088                                     p->p_pid, p->p_ptevents,
1089                                     (u_long)(uintfptr_t)addr, data);
1090                                 break;
1091                         case PT_TO_SCX:
1092                                 p->p_ptevents |= PTRACE_SCX;
1093                                 CTR4(KTR_PTRACE,
1094                     "PT_TO_SCX: pid %d, events = %#x, PC = %#lx, sig = %d",
1095                                     p->p_pid, p->p_ptevents,
1096                                     (u_long)(uintfptr_t)addr, data);
1097                                 break;
1098                         case PT_SYSCALL:
1099                                 p->p_ptevents |= PTRACE_SYSCALL;
1100                                 CTR4(KTR_PTRACE,
1101                     "PT_SYSCALL: pid %d, events = %#x, PC = %#lx, sig = %d",
1102                                     p->p_pid, p->p_ptevents,
1103                                     (u_long)(uintfptr_t)addr, data);
1104                                 break;
1105                         case PT_CONTINUE:
1106                                 CTR3(KTR_PTRACE,
1107                                     "PT_CONTINUE: pid %d, PC = %#lx, sig = %d",
1108                                     p->p_pid, (u_long)(uintfptr_t)addr, data);
1109                                 break;
1110                         }
1111                         break;
1112                 case PT_DETACH:
1113                         /*
1114                          * Reset the process parent.
1115                          *
1116                          * NB: This clears P_TRACED before reparenting
1117                          * a detached process back to its original
1118                          * parent.  Otherwise the debugee will be set
1119                          * as an orphan of the debugger.
1120                          */
1121                         p->p_flag &= ~(P_TRACED | P_WAITED);
1122                         if (p->p_oppid != p->p_pptr->p_pid) {
1123                                 PROC_LOCK(p->p_pptr);
1124                                 sigqueue_take(p->p_ksi);
1125                                 PROC_UNLOCK(p->p_pptr);
1126
1127                                 pp = proc_realparent(p);
1128                                 proc_reparent(p, pp, false);
1129                                 if (pp == initproc)
1130                                         p->p_sigparent = SIGCHLD;
1131                                 CTR3(KTR_PTRACE,
1132                             "PT_DETACH: pid %d reparented to pid %d, sig %d",
1133                                     p->p_pid, pp->p_pid, data);
1134                         } else
1135                                 CTR2(KTR_PTRACE, "PT_DETACH: pid %d, sig %d",
1136                                     p->p_pid, data);
1137                         p->p_ptevents = 0;
1138                         FOREACH_THREAD_IN_PROC(p, td3) {
1139                                 if ((td3->td_dbgflags & TDB_FSTP) != 0) {
1140                                         sigqueue_delete(&td3->td_sigqueue,
1141                                             SIGSTOP);
1142                                 }
1143                                 td3->td_dbgflags &= ~(TDB_XSIG | TDB_FSTP |
1144                                     TDB_SUSPEND);
1145                         }
1146
1147                         if ((p->p_flag2 & P2_PTRACE_FSTP) != 0) {
1148                                 sigqueue_delete(&p->p_sigqueue, SIGSTOP);
1149                                 p->p_flag2 &= ~P2_PTRACE_FSTP;
1150                         }
1151
1152                         /* should we send SIGCHLD? */
1153                         /* childproc_continued(p); */
1154                         break;
1155                 }
1156
1157                 sx_xunlock(&proctree_lock);
1158                 proctree_locked = 0;
1159
1160         sendsig:
1161                 MPASS(proctree_locked == 0);
1162
1163                 /*
1164                  * Clear the pending event for the thread that just
1165                  * reported its event (p_xthread).  This may not be
1166                  * the thread passed to PT_CONTINUE, PT_STEP, etc. if
1167                  * the debugger is resuming a different thread.
1168                  *
1169                  * Deliver any pending signal via the reporting thread.
1170                  */
1171                 MPASS(p->p_xthread != NULL);
1172                 p->p_xthread->td_dbgflags &= ~TDB_XSIG;
1173                 p->p_xthread->td_xsig = data;
1174                 p->p_xthread = NULL;
1175                 p->p_xsig = data;
1176
1177                 /*
1178                  * P_WKILLED is insurance that a PT_KILL/SIGKILL
1179                  * always works immediately, even if another thread is
1180                  * unsuspended first and attempts to handle a
1181                  * different signal or if the POSIX.1b style signal
1182                  * queue cannot accommodate any new signals.
1183                  */
1184                 if (data == SIGKILL)
1185                         proc_wkilled(p);
1186
1187                 /*
1188                  * Unsuspend all threads.  To leave a thread
1189                  * suspended, use PT_SUSPEND to suspend it before
1190                  * continuing the process.
1191                  */
1192                 PROC_SLOCK(p);
1193                 p->p_flag &= ~(P_STOPPED_TRACE | P_STOPPED_SIG | P_WAITED);
1194                 thread_unsuspend(p);
1195                 PROC_SUNLOCK(p);
1196                 break;
1197
1198         case PT_WRITE_I:
1199         case PT_WRITE_D:
1200                 td2->td_dbgflags |= TDB_USERWR;
1201                 PROC_UNLOCK(p);
1202                 error = 0;
1203                 if (proc_writemem(td, p, (off_t)(uintptr_t)addr, &data,
1204                     sizeof(int)) != sizeof(int))
1205                         error = ENOMEM;
1206                 else
1207                         CTR3(KTR_PTRACE, "PT_WRITE: pid %d: %p <= %#x",
1208                             p->p_pid, addr, data);
1209                 PROC_LOCK(p);
1210                 break;
1211
1212         case PT_READ_I:
1213         case PT_READ_D:
1214                 PROC_UNLOCK(p);
1215                 error = tmp = 0;
1216                 if (proc_readmem(td, p, (off_t)(uintptr_t)addr, &tmp,
1217                     sizeof(int)) != sizeof(int))
1218                         error = ENOMEM;
1219                 else
1220                         CTR3(KTR_PTRACE, "PT_READ: pid %d: %p >= %#x",
1221                             p->p_pid, addr, tmp);
1222                 td->td_retval[0] = tmp;
1223                 PROC_LOCK(p);
1224                 break;
1225
1226         case PT_IO:
1227 #ifdef COMPAT_FREEBSD32
1228                 if (wrap32) {
1229                         piod32 = addr;
1230                         iov.iov_base = (void *)(uintptr_t)piod32->piod_addr;
1231                         iov.iov_len = piod32->piod_len;
1232                         uio.uio_offset = (off_t)(uintptr_t)piod32->piod_offs;
1233                         uio.uio_resid = piod32->piod_len;
1234                 } else
1235 #endif
1236                 {
1237                         piod = addr;
1238                         iov.iov_base = piod->piod_addr;
1239                         iov.iov_len = piod->piod_len;
1240                         uio.uio_offset = (off_t)(uintptr_t)piod->piod_offs;
1241                         uio.uio_resid = piod->piod_len;
1242                 }
1243                 uio.uio_iov = &iov;
1244                 uio.uio_iovcnt = 1;
1245                 uio.uio_segflg = UIO_USERSPACE;
1246                 uio.uio_td = td;
1247 #ifdef COMPAT_FREEBSD32
1248                 tmp = wrap32 ? piod32->piod_op : piod->piod_op;
1249 #else
1250                 tmp = piod->piod_op;
1251 #endif
1252                 switch (tmp) {
1253                 case PIOD_READ_D:
1254                 case PIOD_READ_I:
1255                         CTR3(KTR_PTRACE, "PT_IO: pid %d: READ (%p, %#x)",
1256                             p->p_pid, (uintptr_t)uio.uio_offset, uio.uio_resid);
1257                         uio.uio_rw = UIO_READ;
1258                         break;
1259                 case PIOD_WRITE_D:
1260                 case PIOD_WRITE_I:
1261                         CTR3(KTR_PTRACE, "PT_IO: pid %d: WRITE (%p, %#x)",
1262                             p->p_pid, (uintptr_t)uio.uio_offset, uio.uio_resid);
1263                         td2->td_dbgflags |= TDB_USERWR;
1264                         uio.uio_rw = UIO_WRITE;
1265                         break;
1266                 default:
1267                         error = EINVAL;
1268                         goto out;
1269                 }
1270                 PROC_UNLOCK(p);
1271                 error = proc_rwmem(p, &uio);
1272 #ifdef COMPAT_FREEBSD32
1273                 if (wrap32)
1274                         piod32->piod_len -= uio.uio_resid;
1275                 else
1276 #endif
1277                         piod->piod_len -= uio.uio_resid;
1278                 PROC_LOCK(p);
1279                 break;
1280
1281         case PT_KILL:
1282                 CTR1(KTR_PTRACE, "PT_KILL: pid %d", p->p_pid);
1283                 data = SIGKILL;
1284                 goto sendsig;   /* in PT_CONTINUE above */
1285
1286         case PT_SETREGS:
1287                 CTR2(KTR_PTRACE, "PT_SETREGS: tid %d (pid %d)", td2->td_tid,
1288                     p->p_pid);
1289                 td2->td_dbgflags |= TDB_USERWR;
1290                 error = PROC_WRITE(regs, td2, addr);
1291                 break;
1292
1293         case PT_GETREGS:
1294                 CTR2(KTR_PTRACE, "PT_GETREGS: tid %d (pid %d)", td2->td_tid,
1295                     p->p_pid);
1296                 error = PROC_READ(regs, td2, addr);
1297                 break;
1298
1299         case PT_SETFPREGS:
1300                 CTR2(KTR_PTRACE, "PT_SETFPREGS: tid %d (pid %d)", td2->td_tid,
1301                     p->p_pid);
1302                 td2->td_dbgflags |= TDB_USERWR;
1303                 error = PROC_WRITE(fpregs, td2, addr);
1304                 break;
1305
1306         case PT_GETFPREGS:
1307                 CTR2(KTR_PTRACE, "PT_GETFPREGS: tid %d (pid %d)", td2->td_tid,
1308                     p->p_pid);
1309                 error = PROC_READ(fpregs, td2, addr);
1310                 break;
1311
1312         case PT_SETDBREGS:
1313                 CTR2(KTR_PTRACE, "PT_SETDBREGS: tid %d (pid %d)", td2->td_tid,
1314                     p->p_pid);
1315                 td2->td_dbgflags |= TDB_USERWR;
1316                 error = PROC_WRITE(dbregs, td2, addr);
1317                 break;
1318
1319         case PT_GETDBREGS:
1320                 CTR2(KTR_PTRACE, "PT_GETDBREGS: tid %d (pid %d)", td2->td_tid,
1321                     p->p_pid);
1322                 error = PROC_READ(dbregs, td2, addr);
1323                 break;
1324
1325         case PT_LWPINFO:
1326                 if (data <= 0 ||
1327 #ifdef COMPAT_FREEBSD32
1328                     (!wrap32 && data > sizeof(*pl)) ||
1329                     (wrap32 && data > sizeof(*pl32))) {
1330 #else
1331                     data > sizeof(*pl)) {
1332 #endif
1333                         error = EINVAL;
1334                         break;
1335                 }
1336 #ifdef COMPAT_FREEBSD32
1337                 if (wrap32) {
1338                         pl = &plr;
1339                         pl32 = addr;
1340                 } else
1341 #endif
1342                 pl = addr;
1343                 bzero(pl, sizeof(*pl));
1344                 pl->pl_lwpid = td2->td_tid;
1345                 pl->pl_event = PL_EVENT_NONE;
1346                 pl->pl_flags = 0;
1347                 if (td2->td_dbgflags & TDB_XSIG) {
1348                         pl->pl_event = PL_EVENT_SIGNAL;
1349                         if (td2->td_si.si_signo != 0 &&
1350 #ifdef COMPAT_FREEBSD32
1351                             ((!wrap32 && data >= offsetof(struct ptrace_lwpinfo,
1352                             pl_siginfo) + sizeof(pl->pl_siginfo)) ||
1353                             (wrap32 && data >= offsetof(struct ptrace_lwpinfo32,
1354                             pl_siginfo) + sizeof(struct siginfo32)))
1355 #else
1356                             data >= offsetof(struct ptrace_lwpinfo, pl_siginfo)
1357                             + sizeof(pl->pl_siginfo)
1358 #endif
1359                         ){
1360                                 pl->pl_flags |= PL_FLAG_SI;
1361                                 pl->pl_siginfo = td2->td_si;
1362                         }
1363                 }
1364                 if (td2->td_dbgflags & TDB_SCE)
1365                         pl->pl_flags |= PL_FLAG_SCE;
1366                 else if (td2->td_dbgflags & TDB_SCX)
1367                         pl->pl_flags |= PL_FLAG_SCX;
1368                 if (td2->td_dbgflags & TDB_EXEC)
1369                         pl->pl_flags |= PL_FLAG_EXEC;
1370                 if (td2->td_dbgflags & TDB_FORK) {
1371                         pl->pl_flags |= PL_FLAG_FORKED;
1372                         pl->pl_child_pid = td2->td_dbg_forked;
1373                         if (td2->td_dbgflags & TDB_VFORK)
1374                                 pl->pl_flags |= PL_FLAG_VFORKED;
1375                 } else if ((td2->td_dbgflags & (TDB_SCX | TDB_VFORK)) ==
1376                     TDB_VFORK)
1377                         pl->pl_flags |= PL_FLAG_VFORK_DONE;
1378                 if (td2->td_dbgflags & TDB_CHILD)
1379                         pl->pl_flags |= PL_FLAG_CHILD;
1380                 if (td2->td_dbgflags & TDB_BORN)
1381                         pl->pl_flags |= PL_FLAG_BORN;
1382                 if (td2->td_dbgflags & TDB_EXIT)
1383                         pl->pl_flags |= PL_FLAG_EXITED;
1384                 pl->pl_sigmask = td2->td_sigmask;
1385                 pl->pl_siglist = td2->td_siglist;
1386                 strcpy(pl->pl_tdname, td2->td_name);
1387                 if ((td2->td_dbgflags & (TDB_SCE | TDB_SCX)) != 0) {
1388                         pl->pl_syscall_code = td2->td_sa.code;
1389                         pl->pl_syscall_narg = td2->td_sa.narg;
1390                 } else {
1391                         pl->pl_syscall_code = 0;
1392                         pl->pl_syscall_narg = 0;
1393                 }
1394 #ifdef COMPAT_FREEBSD32
1395                 if (wrap32)
1396                         ptrace_lwpinfo_to32(pl, pl32);
1397 #endif
1398                 CTR6(KTR_PTRACE,
1399     "PT_LWPINFO: tid %d (pid %d) event %d flags %#x child pid %d syscall %d",
1400                     td2->td_tid, p->p_pid, pl->pl_event, pl->pl_flags,
1401                     pl->pl_child_pid, pl->pl_syscall_code);
1402                 break;
1403
1404         case PT_GETNUMLWPS:
1405                 CTR2(KTR_PTRACE, "PT_GETNUMLWPS: pid %d: %d threads", p->p_pid,
1406                     p->p_numthreads);
1407                 td->td_retval[0] = p->p_numthreads;
1408                 break;
1409
1410         case PT_GETLWPLIST:
1411                 CTR3(KTR_PTRACE, "PT_GETLWPLIST: pid %d: data %d, actual %d",
1412                     p->p_pid, data, p->p_numthreads);
1413                 if (data <= 0) {
1414                         error = EINVAL;
1415                         break;
1416                 }
1417                 num = imin(p->p_numthreads, data);
1418                 PROC_UNLOCK(p);
1419                 buf = malloc(num * sizeof(lwpid_t), M_TEMP, M_WAITOK);
1420                 tmp = 0;
1421                 PROC_LOCK(p);
1422                 FOREACH_THREAD_IN_PROC(p, td2) {
1423                         if (tmp >= num)
1424                                 break;
1425                         buf[tmp++] = td2->td_tid;
1426                 }
1427                 PROC_UNLOCK(p);
1428                 error = copyout(buf, addr, tmp * sizeof(lwpid_t));
1429                 free(buf, M_TEMP);
1430                 if (!error)
1431                         td->td_retval[0] = tmp;
1432                 PROC_LOCK(p);
1433                 break;
1434
1435         case PT_VM_TIMESTAMP:
1436                 CTR2(KTR_PTRACE, "PT_VM_TIMESTAMP: pid %d: timestamp %d",
1437                     p->p_pid, p->p_vmspace->vm_map.timestamp);
1438                 td->td_retval[0] = p->p_vmspace->vm_map.timestamp;
1439                 break;
1440
1441         case PT_VM_ENTRY:
1442                 PROC_UNLOCK(p);
1443 #ifdef COMPAT_FREEBSD32
1444                 if (wrap32)
1445                         error = ptrace_vm_entry32(td, p, addr);
1446                 else
1447 #endif
1448                 error = ptrace_vm_entry(td, p, addr);
1449                 PROC_LOCK(p);
1450                 break;
1451
1452         default:
1453 #ifdef __HAVE_PTRACE_MACHDEP
1454                 if (req >= PT_FIRSTMACH) {
1455                         PROC_UNLOCK(p);
1456                         error = cpu_ptrace(td2, req, addr, data);
1457                         PROC_LOCK(p);
1458                 } else
1459 #endif
1460                         /* Unknown request. */
1461                         error = EINVAL;
1462                 break;
1463         }
1464
1465 out:
1466         /* Drop our hold on this process now that the request has completed. */
1467         _PRELE(p);
1468 fail:
1469         PROC_UNLOCK(p);
1470         if (proctree_locked)
1471                 sx_xunlock(&proctree_lock);
1472         return (error);
1473 }
1474 #undef PROC_READ
1475 #undef PROC_WRITE
1476
1477 /*
1478  * Stop a process because of a debugging event;
1479  * stay stopped until p->p_step is cleared
1480  * (cleared by PIOCCONT in procfs).
1481  */
1482 void
1483 stopevent(struct proc *p, unsigned int event, unsigned int val)
1484 {
1485
1486         PROC_LOCK_ASSERT(p, MA_OWNED);
1487         p->p_step = 1;
1488         CTR3(KTR_PTRACE, "stopevent: pid %d event %u val %u", p->p_pid, event,
1489             val);
1490         do {
1491                 if (event != S_EXIT)
1492                         p->p_xsig = val;
1493                 p->p_xthread = NULL;
1494                 p->p_stype = event;     /* Which event caused the stop? */
1495                 wakeup(&p->p_stype);    /* Wake up any PIOCWAIT'ing procs */
1496                 msleep(&p->p_step, &p->p_mtx, PWAIT, "stopevent", 0);
1497         } while (p->p_step);
1498 }