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         pid_t   pl_child_pid;           /* New child pid */
 100         u_int           pl_syscall_code;
 101         u_int           pl_syscall_narg;
 102 };
 103
 104 #endif
 105
 106 /*
 107  * Functions implemented using PROC_ACTION():
 108  *
 109  * proc_read_regs(proc, regs)
 110  *      Get the current user-visible register set from the process
 111  *      and copy it into the regs structure (<machine/reg.h>).
 112  *      The process is stopped at the time read_regs is called.
 113  *
 114  * proc_write_regs(proc, regs)
 115  *      Update the current register set from the passed in regs
 116  *      structure.  Take care to avoid clobbering special CPU
 117  *      registers or privileged bits in the PSL.
 118  *      Depending on the architecture this may have fix-up work to do,
 119  *      especially if the IAR or PCW are modified.
 120  *      The process is stopped at the time write_regs is called.
 121  *
 122  * proc_read_fpregs, proc_write_fpregs
 123  *      deal with the floating point register set, otherwise as above.
 124  *
 125  * proc_read_dbregs, proc_write_dbregs
 126  *      deal with the processor debug register set, otherwise as above.
 127  *
 128  * proc_sstep(proc)
 129  *      Arrange for the process to trap after executing a single instruction.
 130  */
 131
 132 #define PROC_ACTION(action) do {                                        \
 133         int error;                                                      \
 134                                                                         \
 135         PROC_LOCK_ASSERT(td->td_proc, MA_OWNED);                        \
 136         if ((td->td_proc->p_flag & P_INMEM) == 0)                       \
 137                 error = EIO;                                            \
 138         else                                                            \
 139                 error = (action);                                       \
 140         return (error);                                                 \
 141 } while(0)
 142
 143 int
 144 proc_read_regs(struct thread *td, struct reg *regs)
 145 {
 146
 147         PROC_ACTION(fill_regs(td, regs));
 148 }
 149
 150 int
 151 proc_write_regs(struct thread *td, struct reg *regs)
 152 {
 153
 154         PROC_ACTION(set_regs(td, regs));
 155 }
 156
 157 int
 158 proc_read_dbregs(struct thread *td, struct dbreg *dbregs)
 159 {
 160
 161         PROC_ACTION(fill_dbregs(td, dbregs));
 162 }
 163
 164 int
 165 proc_write_dbregs(struct thread *td, struct dbreg *dbregs)
 166 {
 167
 168         PROC_ACTION(set_dbregs(td, dbregs));
 169 }
 170
 171 /*
 172  * Ptrace doesn't support fpregs at all, and there are no security holes
 173  * or translations for fpregs, so we can just copy them.
 174  */
 175 int
 176 proc_read_fpregs(struct thread *td, struct fpreg *fpregs)
 177 {
 178
 179         PROC_ACTION(fill_fpregs(td, fpregs));
 180 }
 181
 182 int
 183 proc_write_fpregs(struct thread *td, struct fpreg *fpregs)
 184 {
 185
 186         PROC_ACTION(set_fpregs(td, fpregs));
 187 }
 188
 189 #ifdef COMPAT_FREEBSD32
 190 /* For 32 bit binaries, we need to expose the 32 bit regs layouts. */
 191 int
 192 proc_read_regs32(struct thread *td, struct reg32 *regs32)
 193 {
 194
 195         PROC_ACTION(fill_regs32(td, regs32));
 196 }
 197
 198 int
 199 proc_write_regs32(struct thread *td, struct reg32 *regs32)
 200 {
 201
 202         PROC_ACTION(set_regs32(td, regs32));
 203 }
 204
 205 int
 206 proc_read_dbregs32(struct thread *td, struct dbreg32 *dbregs32)
 207 {
 208
 209         PROC_ACTION(fill_dbregs32(td, dbregs32));
 210 }
 211
 212 int
 213 proc_write_dbregs32(struct thread *td, struct dbreg32 *dbregs32)
 214 {
 215
 216         PROC_ACTION(set_dbregs32(td, dbregs32));
 217 }
 218
 219 int
 220 proc_read_fpregs32(struct thread *td, struct fpreg32 *fpregs32)
 221 {
 222
 223         PROC_ACTION(fill_fpregs32(td, fpregs32));
 224 }
 225
 226 int
 227 proc_write_fpregs32(struct thread *td, struct fpreg32 *fpregs32)
 228 {
 229
 230         PROC_ACTION(set_fpregs32(td, fpregs32));
 231 }
 232 #endif
 233
 234 int
 235 proc_sstep(struct thread *td)
 236 {
 237
 238         PROC_ACTION(ptrace_single_step(td));
 239 }
 240
 241 int
 242 proc_rwmem(struct proc *p, struct uio *uio)
 243 {
 244         vm_map_t map;
 245         vm_offset_t pageno;             /* page number */
 246         vm_prot_t reqprot;
 247         int error, fault_flags, page_offset, writing;
 248
 249         /*
 250          * Assert that someone has locked this vmspace.  (Should be
 251          * curthread but we can't assert that.)  This keeps the process
 252          * from exiting out from under us until this operation completes.
 253          */
 254         PROC_ASSERT_HELD(p);
 255         PROC_LOCK_ASSERT(p, MA_NOTOWNED);
 256
 257         /*
 258          * The map we want...
 259          */
 260         map = &p->p_vmspace->vm_map;
 261
 262         /*
 263          * If we are writing, then we request vm_fault() to create a private
 264          * copy of each page.  Since these copies will not be writeable by the
 265          * process, we must explicity request that they be dirtied.
 266          */
 267         writing = uio->uio_rw == UIO_WRITE;
 268         reqprot = writing ? VM_PROT_COPY | VM_PROT_READ : VM_PROT_READ;
 269         fault_flags = writing ? VM_FAULT_DIRTY : VM_FAULT_NORMAL;
 270
 271         /*
 272          * Only map in one page at a time.  We don't have to, but it
 273          * makes things easier.  This way is trivial - right?
 274          */
 275         do {
 276                 vm_offset_t uva;
 277                 u_int len;
 278                 vm_page_t m;
 279
 280                 uva = (vm_offset_t)uio->uio_offset;
 281
 282                 /*
 283                  * Get the page number of this segment.
 284                  */
 285                 pageno = trunc_page(uva);
 286                 page_offset = uva - pageno;
 287
 288                 /*
 289                  * How many bytes to copy
 290                  */
 291                 len = min(PAGE_SIZE - page_offset, uio->uio_resid);
 292
 293                 /*
 294                  * Fault and hold the page on behalf of the process.
 295                  */
 296                 error = vm_fault_hold(map, pageno, reqprot, fault_flags, &m);
 297                 if (error != KERN_SUCCESS) {
 298                         if (error == KERN_RESOURCE_SHORTAGE)
 299                                 error = ENOMEM;
 300                         else
 301                                 error = EFAULT;
 302                         break;
 303                 }
 304
 305                 /*
 306                  * Now do the i/o move.
 307                  */
 308                 error = uiomove_fromphys(&m, page_offset, len, uio);
 309
 310                 /* Make the I-cache coherent for breakpoints. */
 311                 if (writing && error == 0) {
 312                         vm_map_lock_read(map);
 313                         if (vm_map_check_protection(map, pageno, pageno +
 314                             PAGE_SIZE, VM_PROT_EXECUTE))
 315                                 vm_sync_icache(map, uva, len);
 316                         vm_map_unlock_read(map);
 317                 }
 318
 319                 /*
 320                  * Release the page.
 321                  */
 322                 vm_page_lock(m);
 323                 vm_page_unhold(m);
 324                 vm_page_unlock(m);
 325
 326         } while (error == 0 && uio->uio_resid > 0);
 327
 328         return (error);
 329 }
 330
 331 static ssize_t
 332 proc_iop(struct thread *td, struct proc *p, vm_offset_t va, void *buf,
 333     size_t len, enum uio_rw rw)
 334 {
 335         struct iovec iov;
 336         struct uio uio;
 337         ssize_t slen;
 338         int error;
 339
 340         MPASS(len < SSIZE_MAX);
 341         slen = (ssize_t)len;
 342
 343         iov.iov_base = (caddr_t)buf;
 344         iov.iov_len = len;
 345         uio.uio_iov = &iov;
 346         uio.uio_iovcnt = 1;
 347         uio.uio_offset = va;
 348         uio.uio_resid = slen;
 349         uio.uio_segflg = UIO_SYSSPACE;
 350         uio.uio_rw = rw;
 351         uio.uio_td = td;
 352         error = proc_rwmem(p, &uio);
 353         if (uio.uio_resid == slen)
 354                 return (-1);
 355         return (slen - uio.uio_resid);
 356 }
 357
 358 ssize_t
 359 proc_readmem(struct thread *td, struct proc *p, vm_offset_t va, void *buf,
 360     size_t len)
 361 {
 362
 363         return (proc_iop(td, p, va, buf, len, UIO_READ));
 364 }
 365
 366 ssize_t
 367 proc_writemem(struct thread *td, struct proc *p, vm_offset_t va, void *buf,
 368     size_t len)
 369 {
 370
 371         return (proc_iop(td, p, va, buf, len, UIO_WRITE));
 372 }
 373
 374 static int
 375 ptrace_vm_entry(struct thread *td, struct proc *p, struct ptrace_vm_entry *pve)
 376 {
 377         struct vattr vattr;
 378         vm_map_t map;
 379         vm_map_entry_t entry;
 380         vm_object_t obj, tobj, lobj;
 381         struct vmspace *vm;
 382         struct vnode *vp;
 383         char *freepath, *fullpath;
 384         u_int pathlen;
 385         int error, index;
 386
 387         error = 0;
 388         obj = NULL;
 389
 390         vm = vmspace_acquire_ref(p);
 391         map = &vm->vm_map;
 392         vm_map_lock_read(map);
 393
 394         do {
 395                 entry = map->header.next;
 396                 index = 0;
 397                 while (index < pve->pve_entry && entry != &map->header) {
 398                         entry = entry->next;
 399                         index++;
 400                 }
 401                 if (index != pve->pve_entry) {
 402                         error = EINVAL;
 403                         break;
 404                 }
 405                 while (entry != &map->header &&
 406                     (entry->eflags & MAP_ENTRY_IS_SUB_MAP) != 0) {
 407                         entry = entry->next;
 408                         index++;
 409                 }
 410                 if (entry == &map->header) {
 411                         error = ENOENT;
 412                         break;
 413                 }
 414
 415                 /* We got an entry. */
 416                 pve->pve_entry = index + 1;
 417                 pve->pve_timestamp = map->timestamp;
 418                 pve->pve_start = entry->start;
 419                 pve->pve_end = entry->end - 1;
 420                 pve->pve_offset = entry->offset;
 421                 pve->pve_prot = entry->protection;
 422
 423                 /* Backing object's path needed? */
 424                 if (pve->pve_pathlen == 0)
 425                         break;
 426
 427                 pathlen = pve->pve_pathlen;
 428                 pve->pve_pathlen = 0;
 429
 430                 obj = entry->object.vm_object;
 431                 if (obj != NULL)
 432                         VM_OBJECT_RLOCK(obj);
 433         } while (0);
 434
 435         vm_map_unlock_read(map);
 436
 437         pve->pve_fsid = VNOVAL;
 438         pve->pve_fileid = VNOVAL;
 439
 440         if (error == 0 && obj != NULL) {
 441                 lobj = obj;
 442                 for (tobj = obj; tobj != NULL; tobj = tobj->backing_object) {
 443                         if (tobj != obj)
 444                                 VM_OBJECT_RLOCK(tobj);
 445                         if (lobj != obj)
 446                                 VM_OBJECT_RUNLOCK(lobj);
 447                         lobj = tobj;
 448                         pve->pve_offset += tobj->backing_object_offset;
 449                 }
 450                 vp = vm_object_vnode(lobj);
 451                 if (vp != NULL)
 452                         vref(vp);
 453                 if (lobj != obj)
 454                         VM_OBJECT_RUNLOCK(lobj);
 455                 VM_OBJECT_RUNLOCK(obj);
 456
 457                 if (vp != NULL) {
 458                         freepath = NULL;
 459                         fullpath = NULL;
 460                         vn_fullpath(td, vp, &fullpath, &freepath);
 461                         vn_lock(vp, LK_SHARED | LK_RETRY);
 462                         if (VOP_GETATTR(vp, &vattr, td->td_ucred) == 0) {
 463                                 pve->pve_fileid = vattr.va_fileid;
 464                                 pve->pve_fsid = vattr.va_fsid;
 465                         }
 466                         vput(vp);
 467
 468                         if (fullpath != NULL) {
 469                                 pve->pve_pathlen = strlen(fullpath) + 1;
 470                                 if (pve->pve_pathlen <= pathlen) {
 471                                         error = copyout(fullpath, pve->pve_path,
 472                                             pve->pve_pathlen);
 473                                 } else
 474                                         error = ENAMETOOLONG;
 475                         }
 476                         if (freepath != NULL)
 477                                 free(freepath, M_TEMP);
 478                 }
 479         }
 480         vmspace_free(vm);
 481         if (error == 0)
 482                 CTR3(KTR_PTRACE, "PT_VM_ENTRY: pid %d, entry %d, start %p",
 483                     p->p_pid, pve->pve_entry, pve->pve_start);
 484
 485         return (error);
 486 }
 487
 488 #ifdef COMPAT_FREEBSD32
 489 static int
 490 ptrace_vm_entry32(struct thread *td, struct proc *p,
 491     struct ptrace_vm_entry32 *pve32)
 492 {
 493         struct ptrace_vm_entry pve;
 494         int error;
 495
 496         pve.pve_entry = pve32->pve_entry;
 497         pve.pve_pathlen = pve32->pve_pathlen;
 498         pve.pve_path = (void *)(uintptr_t)pve32->pve_path;
 499
 500         error = ptrace_vm_entry(td, p, &pve);
 501         if (error == 0) {
 502                 pve32->pve_entry = pve.pve_entry;
 503                 pve32->pve_timestamp = pve.pve_timestamp;
 504                 pve32->pve_start = pve.pve_start;
 505                 pve32->pve_end = pve.pve_end;
 506                 pve32->pve_offset = pve.pve_offset;
 507                 pve32->pve_prot = pve.pve_prot;
 508                 pve32->pve_fileid = pve.pve_fileid;
 509                 pve32->pve_fsid = pve.pve_fsid;
 510         }
 511
 512         pve32->pve_pathlen = pve.pve_pathlen;
 513         return (error);
 514 }
 515
 516 static void
 517 ptrace_lwpinfo_to32(const struct ptrace_lwpinfo *pl,
 518     struct ptrace_lwpinfo32 *pl32)
 519 {
 520
 521         pl32->pl_lwpid = pl->pl_lwpid;
 522         pl32->pl_event = pl->pl_event;
 523         pl32->pl_flags = pl->pl_flags;
 524         pl32->pl_sigmask = pl->pl_sigmask;
 525         pl32->pl_siglist = pl->pl_siglist;
 526         siginfo_to_siginfo32(&pl->pl_siginfo, &pl32->pl_siginfo);
 527         strcpy(pl32->pl_tdname, pl->pl_tdname);
 528         pl32->pl_child_pid = pl->pl_child_pid;
 529         pl32->pl_syscall_code = pl->pl_syscall_code;
 530         pl32->pl_syscall_narg = pl->pl_syscall_narg;
 531 }
 532 #endif /* COMPAT_FREEBSD32 */
 533
 534 /*
 535  * Process debugging system call.
 536  */
 537 #ifndef _SYS_SYSPROTO_H_
 538 struct ptrace_args {
 539         int     req;
 540         pid_t   pid;
 541         caddr_t addr;
 542         int     data;
 543 };
 544 #endif
 545
 546 #ifdef COMPAT_FREEBSD32
 547 /*
 548  * This CPP subterfuge is to try and reduce the number of ifdefs in
 549  * the body of the code.
 550  *   COPYIN(uap->addr, &r.reg, sizeof r.reg);
 551  * becomes either:
 552  *   copyin(uap->addr, &r.reg, sizeof r.reg);
 553  * or
 554  *   copyin(uap->addr, &r.reg32, sizeof r.reg32);
 555  * .. except this is done at runtime.
 556  */
 557 #define COPYIN(u, k, s)         wrap32 ? \
 558         copyin(u, k ## 32, s ## 32) : \
 559         copyin(u, k, s)
 560 #define COPYOUT(k, u, s)        wrap32 ? \
 561         copyout(k ## 32, u, s ## 32) : \
 562         copyout(k, u, s)
 563 #else
 564 #define COPYIN(u, k, s)         copyin(u, k, s)
 565 #define COPYOUT(k, u, s)        copyout(k, u, s)
 566 #endif
 567 int
 568 sys_ptrace(struct thread *td, struct ptrace_args *uap)
 569 {
 570         /*
 571          * XXX this obfuscation is to reduce stack usage, but the register
 572          * structs may be too large to put on the stack anyway.
 573          */
 574         union {
 575                 struct ptrace_io_desc piod;
 576                 struct ptrace_lwpinfo pl;
 577                 struct ptrace_vm_entry pve;
 578                 struct dbreg dbreg;
 579                 struct fpreg fpreg;
 580                 struct reg reg;
 581 #ifdef COMPAT_FREEBSD32
 582                 struct dbreg32 dbreg32;
 583                 struct fpreg32 fpreg32;
 584                 struct reg32 reg32;
 585                 struct ptrace_io_desc32 piod32;
 586                 struct ptrace_lwpinfo32 pl32;
 587                 struct ptrace_vm_entry32 pve32;
 588 #endif
 589                 char args[nitems(td->td_sa.args) * sizeof(register_t)];
 590                 int ptevents;
 591         } r;
 592         void *addr;
 593         int error = 0;
 594 #ifdef COMPAT_FREEBSD32
 595         int wrap32 = 0;
 596
 597         if (SV_CURPROC_FLAG(SV_ILP32))
 598                 wrap32 = 1;
 599 #endif
 600         AUDIT_ARG_PID(uap->pid);
 601         AUDIT_ARG_CMD(uap->req);
 602         AUDIT_ARG_VALUE(uap->data);
 603         addr = &r;
 604         switch (uap->req) {
 605         case PT_GET_EVENT_MASK:
 606         case PT_GETREGS:
 607         case PT_GETFPREGS:
 608         case PT_GETDBREGS:
 609         case PT_LWPINFO:
 610         case PT_GET_SC_ARGS:
 611                 break;
 612         case PT_SETREGS:
 613                 error = COPYIN(uap->addr, &r.reg, sizeof r.reg);
 614                 break;
 615         case PT_SETFPREGS:
 616                 error = COPYIN(uap->addr, &r.fpreg, sizeof r.fpreg);
 617                 break;
 618         case PT_SETDBREGS:
 619                 error = COPYIN(uap->addr, &r.dbreg, sizeof r.dbreg);
 620                 break;
 621         case PT_SET_EVENT_MASK:
 622                 if (uap->data != sizeof(r.ptevents))
 623                         error = EINVAL;
 624                 else
 625                         error = copyin(uap->addr, &r.ptevents, uap->data);
 626                 break;
 627         case PT_IO:
 628                 error = COPYIN(uap->addr, &r.piod, sizeof r.piod);
 629                 break;
 630         case PT_VM_ENTRY:
 631                 error = COPYIN(uap->addr, &r.pve, sizeof r.pve);
 632                 break;
 633         default:
 634                 addr = uap->addr;
 635                 break;
 636         }
 637         if (error)
 638                 return (error);
 639
 640         error = kern_ptrace(td, uap->req, uap->pid, addr, uap->data);
 641         if (error)
 642                 return (error);
 643
 644         switch (uap->req) {
 645         case PT_VM_ENTRY:
 646                 error = COPYOUT(&r.pve, uap->addr, sizeof r.pve);
 647                 break;
 648         case PT_IO:
 649                 error = COPYOUT(&r.piod, uap->addr, sizeof r.piod);
 650                 break;
 651         case PT_GETREGS:
 652                 error = COPYOUT(&r.reg, uap->addr, sizeof r.reg);
 653                 break;
 654         case PT_GETFPREGS:
 655                 error = COPYOUT(&r.fpreg, uap->addr, sizeof r.fpreg);
 656                 break;
 657         case PT_GETDBREGS:
 658                 error = COPYOUT(&r.dbreg, uap->addr, sizeof r.dbreg);
 659                 break;
 660         case PT_GET_EVENT_MASK:
 661                 /* NB: The size in uap->data is validated in kern_ptrace(). */
 662                 error = copyout(&r.ptevents, uap->addr, uap->data);
 663                 break;
 664         case PT_LWPINFO:
 665                 /* NB: The size in uap->data is validated in kern_ptrace(). */
 666                 error = copyout(&r.pl, uap->addr, uap->data);
 667                 break;
 668         case PT_GET_SC_ARGS:
 669                 error = copyout(r.args, uap->addr, MIN(uap->data,
 670                     sizeof(r.args)));
 671                 break;
 672         }
 673
 674         return (error);
 675 }
 676 #undef COPYIN
 677 #undef COPYOUT
 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         PROC_LOCK_ASSERT(p, MA_OWNED);
 706         p->p_flag |= P_TRACED;
 707         if (stop)
 708                 p->p_flag2 |= P2_PTRACE_FSTP;
 709         p->p_ptevents = PTRACE_DEFAULT;
 710         p->p_oppid = p->p_pptr->p_pid;
 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_SIG | 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                 if ((p->p_flag & P_STOPPED_TRACE) == 0) {
 893                         static int count = 0;
 894                         if (count++ == 0)
 895                                 printf("P_STOPPED_TRACE not set.\n");
 896                 }
 897
 898                 /* OK */
 899                 break;
 900         }
 901
 902         /* Keep this process around until we finish this request. */
 903         _PHOLD(p);
 904
 905 #ifdef FIX_SSTEP
 906         /*
 907          * Single step fixup ala procfs
 908          */
 909         FIX_SSTEP(td2);
 910 #endif
 911
 912         /*
 913          * Actually do the requests
 914          */
 915
 916         td->td_retval[0] = 0;
 917
 918         switch (req) {
 919         case PT_TRACE_ME:
 920                 /* set my trace flag and "owner" so it can read/write me */
 921                 proc_set_traced(p, false);
 922                 if (p->p_flag & P_PPWAIT)
 923                         p->p_flag |= P_PPTRACE;
 924                 CTR1(KTR_PTRACE, "PT_TRACE_ME: pid %d", p->p_pid);
 925                 break;
 926
 927         case PT_ATTACH:
 928                 /* security check done above */
 929                 /*
 930                  * It would be nice if the tracing relationship was separate
 931                  * from the parent relationship but that would require
 932                  * another set of links in the proc struct or for "wait"
 933                  * to scan the entire proc table.  To make life easier,
 934                  * we just re-parent the process we're trying to trace.
 935                  * The old parent is remembered so we can put things back
 936                  * on a "detach".
 937                  */
 938                 proc_set_traced(p, true);
 939                 if (p->p_pptr != td->td_proc) {
 940                         proc_reparent(p, td->td_proc);
 941                 }
 942                 data = SIGSTOP;
 943                 CTR2(KTR_PTRACE, "PT_ATTACH: pid %d, oppid %d", p->p_pid,
 944                     p->p_oppid);
 945                 goto sendsig;   /* in PT_CONTINUE below */
 946
 947         case PT_CLEARSTEP:
 948                 CTR2(KTR_PTRACE, "PT_CLEARSTEP: tid %d (pid %d)", td2->td_tid,
 949                     p->p_pid);
 950                 error = ptrace_clear_single_step(td2);
 951                 break;
 952
 953         case PT_SETSTEP:
 954                 CTR2(KTR_PTRACE, "PT_SETSTEP: tid %d (pid %d)", td2->td_tid,
 955                     p->p_pid);
 956                 error = ptrace_single_step(td2);
 957                 break;
 958
 959         case PT_SUSPEND:
 960                 CTR2(KTR_PTRACE, "PT_SUSPEND: tid %d (pid %d)", td2->td_tid,
 961                     p->p_pid);
 962                 td2->td_dbgflags |= TDB_SUSPEND;
 963                 thread_lock(td2);
 964                 td2->td_flags |= TDF_NEEDSUSPCHK;
 965                 thread_unlock(td2);
 966                 break;
 967
 968         case PT_RESUME:
 969                 CTR2(KTR_PTRACE, "PT_RESUME: tid %d (pid %d)", td2->td_tid,
 970                     p->p_pid);
 971                 td2->td_dbgflags &= ~TDB_SUSPEND;
 972                 break;
 973
 974         case PT_FOLLOW_FORK:
 975                 CTR3(KTR_PTRACE, "PT_FOLLOW_FORK: pid %d %s -> %s", p->p_pid,
 976                     p->p_ptevents & PTRACE_FORK ? "enabled" : "disabled",
 977                     data ? "enabled" : "disabled");
 978                 if (data)
 979                         p->p_ptevents |= PTRACE_FORK;
 980                 else
 981                         p->p_ptevents &= ~PTRACE_FORK;
 982                 break;
 983
 984         case PT_LWP_EVENTS:
 985                 CTR3(KTR_PTRACE, "PT_LWP_EVENTS: pid %d %s -> %s", p->p_pid,
 986                     p->p_ptevents & PTRACE_LWP ? "enabled" : "disabled",
 987                     data ? "enabled" : "disabled");
 988                 if (data)
 989                         p->p_ptevents |= PTRACE_LWP;
 990                 else
 991                         p->p_ptevents &= ~PTRACE_LWP;
 992                 break;
 993
 994         case PT_GET_EVENT_MASK:
 995                 if (data != sizeof(p->p_ptevents)) {
 996                         error = EINVAL;
 997                         break;
 998                 }
 999                 CTR2(KTR_PTRACE, "PT_GET_EVENT_MASK: pid %d mask %#x", p->p_pid,
1000                     p->p_ptevents);
1001                 *(int *)addr = p->p_ptevents;
1002                 break;
1003
1004         case PT_SET_EVENT_MASK:
1005                 if (data != sizeof(p->p_ptevents)) {
1006                         error = EINVAL;
1007                         break;
1008                 }
1009                 tmp = *(int *)addr;
1010                 if ((tmp & ~(PTRACE_EXEC | PTRACE_SCE | PTRACE_SCX |
1011                     PTRACE_FORK | PTRACE_LWP | PTRACE_VFORK)) != 0) {
1012                         error = EINVAL;
1013                         break;
1014                 }
1015                 CTR3(KTR_PTRACE, "PT_SET_EVENT_MASK: pid %d mask %#x -> %#x",
1016                     p->p_pid, p->p_ptevents, tmp);
1017                 p->p_ptevents = tmp;
1018                 break;
1019
1020         case PT_GET_SC_ARGS:
1021                 CTR1(KTR_PTRACE, "PT_GET_SC_ARGS: pid %d", p->p_pid);
1022                 if ((td2->td_dbgflags & (TDB_SCE | TDB_SCX)) == 0
1023 #ifdef COMPAT_FREEBSD32
1024                     || (wrap32 && !safe)
1025 #endif
1026                     ) {
1027                         error = EINVAL;
1028                         break;
1029                 }
1030                 bzero(addr, sizeof(td2->td_sa.args));
1031 #ifdef COMPAT_FREEBSD32
1032                 if (wrap32)
1033                         for (num = 0; num < nitems(td2->td_sa.args); num++)
1034                                 ((uint32_t *)addr)[num] = (uint32_t)
1035                                     td2->td_sa.args[num];
1036                 else
1037 #endif
1038                         bcopy(td2->td_sa.args, addr, td2->td_sa.narg *
1039                             sizeof(register_t));
1040                 break;
1041
1042         case PT_STEP:
1043         case PT_CONTINUE:
1044         case PT_TO_SCE:
1045         case PT_TO_SCX:
1046         case PT_SYSCALL:
1047         case PT_DETACH:
1048                 /* Zero means do not send any signal */
1049                 if (data < 0 || data > _SIG_MAXSIG) {
1050                         error = EINVAL;
1051                         break;
1052                 }
1053
1054                 switch (req) {
1055                 case PT_STEP:
1056                         CTR3(KTR_PTRACE, "PT_STEP: tid %d (pid %d), sig = %d",
1057                             td2->td_tid, p->p_pid, data);
1058                         error = ptrace_single_step(td2);
1059                         if (error)
1060                                 goto out;
1061                         break;
1062                 case PT_CONTINUE:
1063                 case PT_TO_SCE:
1064                 case PT_TO_SCX:
1065                 case PT_SYSCALL:
1066                         if (addr != (void *)1) {
1067                                 error = ptrace_set_pc(td2,
1068                                     (u_long)(uintfptr_t)addr);
1069                                 if (error)
1070                                         goto out;
1071                         }
1072                         switch (req) {
1073                         case PT_TO_SCE:
1074                                 p->p_ptevents |= PTRACE_SCE;
1075                                 CTR4(KTR_PTRACE,
1076                     "PT_TO_SCE: pid %d, events = %#x, PC = %#lx, sig = %d",
1077                                     p->p_pid, p->p_ptevents,
1078                                     (u_long)(uintfptr_t)addr, data);
1079                                 break;
1080                         case PT_TO_SCX:
1081                                 p->p_ptevents |= PTRACE_SCX;
1082                                 CTR4(KTR_PTRACE,
1083                     "PT_TO_SCX: pid %d, events = %#x, PC = %#lx, sig = %d",
1084                                     p->p_pid, p->p_ptevents,
1085                                     (u_long)(uintfptr_t)addr, data);
1086                                 break;
1087                         case PT_SYSCALL:
1088                                 p->p_ptevents |= PTRACE_SYSCALL;
1089                                 CTR4(KTR_PTRACE,
1090                     "PT_SYSCALL: pid %d, events = %#x, PC = %#lx, sig = %d",
1091                                     p->p_pid, p->p_ptevents,
1092                                     (u_long)(uintfptr_t)addr, data);
1093                                 break;
1094                         case PT_CONTINUE:
1095                                 CTR3(KTR_PTRACE,
1096                                     "PT_CONTINUE: pid %d, PC = %#lx, sig = %d",
1097                                     p->p_pid, (u_long)(uintfptr_t)addr, data);
1098                                 break;
1099                         }
1100                         break;
1101                 case PT_DETACH:
1102                         /*
1103                          * Reset the process parent.
1104                          *
1105                          * NB: This clears P_TRACED before reparenting
1106                          * a detached process back to its original
1107                          * parent.  Otherwise the debugee will be set
1108                          * as an orphan of the debugger.
1109                          */
1110                         p->p_flag &= ~(P_TRACED | P_WAITED);
1111                         if (p->p_oppid != p->p_pptr->p_pid) {
1112                                 PROC_LOCK(p->p_pptr);
1113                                 sigqueue_take(p->p_ksi);
1114                                 PROC_UNLOCK(p->p_pptr);
1115
1116                                 pp = proc_realparent(p);
1117                                 proc_reparent(p, pp);
1118                                 if (pp == initproc)
1119                                         p->p_sigparent = SIGCHLD;
1120                                 CTR3(KTR_PTRACE,
1121                             "PT_DETACH: pid %d reparented to pid %d, sig %d",
1122                                     p->p_pid, pp->p_pid, data);
1123                         } else
1124                                 CTR2(KTR_PTRACE, "PT_DETACH: pid %d, sig %d",
1125                                     p->p_pid, data);
1126                         p->p_oppid = 0;
1127                         p->p_ptevents = 0;
1128                         FOREACH_THREAD_IN_PROC(p, td3) {
1129                                 if ((td3->td_dbgflags & TDB_FSTP) != 0) {
1130                                         sigqueue_delete(&td3->td_sigqueue,
1131                                             SIGSTOP);
1132                                 }
1133                                 td3->td_dbgflags &= ~(TDB_XSIG | TDB_FSTP);
1134                         }
1135                         if ((p->p_flag2 & P2_PTRACE_FSTP) != 0) {
1136                                 sigqueue_delete(&p->p_sigqueue, SIGSTOP);
1137                                 p->p_flag2 &= ~P2_PTRACE_FSTP;
1138                         }
1139
1140                         /* should we send SIGCHLD? */
1141                         /* childproc_continued(p); */
1142                         break;
1143                 }
1144
1145         sendsig:
1146                 if (proctree_locked) {
1147                         sx_xunlock(&proctree_lock);
1148                         proctree_locked = 0;
1149                 }
1150                 p->p_xsig = data;
1151                 p->p_xthread = NULL;
1152                 if ((p->p_flag & (P_STOPPED_SIG | P_STOPPED_TRACE)) != 0) {
1153                         /* deliver or queue signal */
1154                         td2->td_dbgflags &= ~TDB_XSIG;
1155                         td2->td_xsig = data;
1156
1157                         /*
1158                          * P_WKILLED is insurance that a PT_KILL/SIGKILL always
1159                          * works immediately, even if another thread is
1160                          * unsuspended first and attempts to handle a different
1161                          * signal or if the POSIX.1b style signal queue cannot
1162                          * accommodate any new signals.
1163                          */
1164                         if (data == SIGKILL)
1165                                 p->p_flag |= P_WKILLED;
1166
1167                         if (req == PT_DETACH) {
1168                                 FOREACH_THREAD_IN_PROC(p, td3)
1169                                         td3->td_dbgflags &= ~TDB_SUSPEND;
1170                         }
1171                         /*
1172                          * unsuspend all threads, to not let a thread run,
1173                          * you should use PT_SUSPEND to suspend it before
1174                          * continuing process.
1175                          */
1176                         PROC_SLOCK(p);
1177                         p->p_flag &= ~(P_STOPPED_TRACE|P_STOPPED_SIG|P_WAITED);
1178                         thread_unsuspend(p);
1179                         PROC_SUNLOCK(p);
1180                         if (req == PT_ATTACH)
1181                                 kern_psignal(p, data);
1182                 } else {
1183                         if (data)
1184                                 kern_psignal(p, data);
1185                 }
1186                 break;
1187
1188         case PT_WRITE_I:
1189         case PT_WRITE_D:
1190                 td2->td_dbgflags |= TDB_USERWR;
1191                 PROC_UNLOCK(p);
1192                 error = 0;
1193                 if (proc_writemem(td, p, (off_t)(uintptr_t)addr, &data,
1194                     sizeof(int)) != sizeof(int))
1195                         error = ENOMEM;
1196                 else
1197                         CTR3(KTR_PTRACE, "PT_WRITE: pid %d: %p <= %#x",
1198                             p->p_pid, addr, data);
1199                 PROC_LOCK(p);
1200                 break;
1201
1202         case PT_READ_I:
1203         case PT_READ_D:
1204                 PROC_UNLOCK(p);
1205                 error = tmp = 0;
1206                 if (proc_readmem(td, p, (off_t)(uintptr_t)addr, &tmp,
1207                     sizeof(int)) != sizeof(int))
1208                         error = ENOMEM;
1209                 else
1210                         CTR3(KTR_PTRACE, "PT_READ: pid %d: %p >= %#x",
1211                             p->p_pid, addr, tmp);
1212                 td->td_retval[0] = tmp;
1213                 PROC_LOCK(p);
1214                 break;
1215
1216         case PT_IO:
1217 #ifdef COMPAT_FREEBSD32
1218                 if (wrap32) {
1219                         piod32 = addr;
1220                         iov.iov_base = (void *)(uintptr_t)piod32->piod_addr;
1221                         iov.iov_len = piod32->piod_len;
1222                         uio.uio_offset = (off_t)(uintptr_t)piod32->piod_offs;
1223                         uio.uio_resid = piod32->piod_len;
1224                 } else
1225 #endif
1226                 {
1227                         piod = addr;
1228                         iov.iov_base = piod->piod_addr;
1229                         iov.iov_len = piod->piod_len;
1230                         uio.uio_offset = (off_t)(uintptr_t)piod->piod_offs;
1231                         uio.uio_resid = piod->piod_len;
1232                 }
1233                 uio.uio_iov = &iov;
1234                 uio.uio_iovcnt = 1;
1235                 uio.uio_segflg = UIO_USERSPACE;
1236                 uio.uio_td = td;
1237 #ifdef COMPAT_FREEBSD32
1238                 tmp = wrap32 ? piod32->piod_op : piod->piod_op;
1239 #else
1240                 tmp = piod->piod_op;
1241 #endif
1242                 switch (tmp) {
1243                 case PIOD_READ_D:
1244                 case PIOD_READ_I:
1245                         CTR3(KTR_PTRACE, "PT_IO: pid %d: READ (%p, %#x)",
1246                             p->p_pid, (uintptr_t)uio.uio_offset, uio.uio_resid);
1247                         uio.uio_rw = UIO_READ;
1248                         break;
1249                 case PIOD_WRITE_D:
1250                 case PIOD_WRITE_I:
1251                         CTR3(KTR_PTRACE, "PT_IO: pid %d: WRITE (%p, %#x)",
1252                             p->p_pid, (uintptr_t)uio.uio_offset, uio.uio_resid);
1253                         td2->td_dbgflags |= TDB_USERWR;
1254                         uio.uio_rw = UIO_WRITE;
1255                         break;
1256                 default:
1257                         error = EINVAL;
1258                         goto out;
1259                 }
1260                 PROC_UNLOCK(p);
1261                 error = proc_rwmem(p, &uio);
1262 #ifdef COMPAT_FREEBSD32
1263                 if (wrap32)
1264                         piod32->piod_len -= uio.uio_resid;
1265                 else
1266 #endif
1267                         piod->piod_len -= uio.uio_resid;
1268                 PROC_LOCK(p);
1269                 break;
1270
1271         case PT_KILL:
1272                 CTR1(KTR_PTRACE, "PT_KILL: pid %d", p->p_pid);
1273                 data = SIGKILL;
1274                 goto sendsig;   /* in PT_CONTINUE above */
1275
1276         case PT_SETREGS:
1277                 CTR2(KTR_PTRACE, "PT_SETREGS: tid %d (pid %d)", td2->td_tid,
1278                     p->p_pid);
1279                 td2->td_dbgflags |= TDB_USERWR;
1280                 error = PROC_WRITE(regs, td2, addr);
1281                 break;
1282
1283         case PT_GETREGS:
1284                 CTR2(KTR_PTRACE, "PT_GETREGS: tid %d (pid %d)", td2->td_tid,
1285                     p->p_pid);
1286                 error = PROC_READ(regs, td2, addr);
1287                 break;
1288
1289         case PT_SETFPREGS:
1290                 CTR2(KTR_PTRACE, "PT_SETFPREGS: tid %d (pid %d)", td2->td_tid,
1291                     p->p_pid);
1292                 td2->td_dbgflags |= TDB_USERWR;
1293                 error = PROC_WRITE(fpregs, td2, addr);
1294                 break;
1295
1296         case PT_GETFPREGS:
1297                 CTR2(KTR_PTRACE, "PT_GETFPREGS: tid %d (pid %d)", td2->td_tid,
1298                     p->p_pid);
1299                 error = PROC_READ(fpregs, td2, addr);
1300                 break;
1301
1302         case PT_SETDBREGS:
1303                 CTR2(KTR_PTRACE, "PT_SETDBREGS: tid %d (pid %d)", td2->td_tid,
1304                     p->p_pid);
1305                 td2->td_dbgflags |= TDB_USERWR;
1306                 error = PROC_WRITE(dbregs, td2, addr);
1307                 break;
1308
1309         case PT_GETDBREGS:
1310                 CTR2(KTR_PTRACE, "PT_GETDBREGS: tid %d (pid %d)", td2->td_tid,
1311                     p->p_pid);
1312                 error = PROC_READ(dbregs, td2, addr);
1313                 break;
1314
1315         case PT_LWPINFO:
1316                 if (data <= 0 ||
1317 #ifdef COMPAT_FREEBSD32
1318                     (!wrap32 && data > sizeof(*pl)) ||
1319                     (wrap32 && data > sizeof(*pl32))) {
1320 #else
1321                     data > sizeof(*pl)) {
1322 #endif
1323                         error = EINVAL;
1324                         break;
1325                 }
1326 #ifdef COMPAT_FREEBSD32
1327                 if (wrap32) {
1328                         pl = &plr;
1329                         pl32 = addr;
1330                 } else
1331 #endif
1332                 pl = addr;
1333                 pl->pl_lwpid = td2->td_tid;
1334                 pl->pl_event = PL_EVENT_NONE;
1335                 pl->pl_flags = 0;
1336                 if (td2->td_dbgflags & TDB_XSIG) {
1337                         pl->pl_event = PL_EVENT_SIGNAL;
1338                         if (td2->td_dbgksi.ksi_signo != 0 &&
1339 #ifdef COMPAT_FREEBSD32
1340                             ((!wrap32 && data >= offsetof(struct ptrace_lwpinfo,
1341                             pl_siginfo) + sizeof(pl->pl_siginfo)) ||
1342                             (wrap32 && data >= offsetof(struct ptrace_lwpinfo32,
1343                             pl_siginfo) + sizeof(struct siginfo32)))
1344 #else
1345                             data >= offsetof(struct ptrace_lwpinfo, pl_siginfo)
1346                             + sizeof(pl->pl_siginfo)
1347 #endif
1348                         ){
1349                                 pl->pl_flags |= PL_FLAG_SI;
1350                                 pl->pl_siginfo = td2->td_dbgksi.ksi_info;
1351                         }
1352                 }
1353                 if ((pl->pl_flags & PL_FLAG_SI) == 0)
1354                         bzero(&pl->pl_siginfo, sizeof(pl->pl_siginfo));
1355                 if (td2->td_dbgflags & TDB_SCE)
1356                         pl->pl_flags |= PL_FLAG_SCE;
1357                 else if (td2->td_dbgflags & TDB_SCX)
1358                         pl->pl_flags |= PL_FLAG_SCX;
1359                 if (td2->td_dbgflags & TDB_EXEC)
1360                         pl->pl_flags |= PL_FLAG_EXEC;
1361                 if (td2->td_dbgflags & TDB_FORK) {
1362                         pl->pl_flags |= PL_FLAG_FORKED;
1363                         pl->pl_child_pid = td2->td_dbg_forked;
1364                         if (td2->td_dbgflags & TDB_VFORK)
1365                                 pl->pl_flags |= PL_FLAG_VFORKED;
1366                 } else if ((td2->td_dbgflags & (TDB_SCX | TDB_VFORK)) ==
1367                     TDB_VFORK)
1368                         pl->pl_flags |= PL_FLAG_VFORK_DONE;
1369                 if (td2->td_dbgflags & TDB_CHILD)
1370                         pl->pl_flags |= PL_FLAG_CHILD;
1371                 if (td2->td_dbgflags & TDB_BORN)
1372                         pl->pl_flags |= PL_FLAG_BORN;
1373                 if (td2->td_dbgflags & TDB_EXIT)
1374                         pl->pl_flags |= PL_FLAG_EXITED;
1375                 pl->pl_sigmask = td2->td_sigmask;
1376                 pl->pl_siglist = td2->td_siglist;
1377                 strcpy(pl->pl_tdname, td2->td_name);
1378                 if ((td2->td_dbgflags & (TDB_SCE | TDB_SCX)) != 0) {
1379                         pl->pl_syscall_code = td2->td_sa.code;
1380                         pl->pl_syscall_narg = td2->td_sa.narg;
1381                 } else {
1382                         pl->pl_syscall_code = 0;
1383                         pl->pl_syscall_narg = 0;
1384                 }
1385 #ifdef COMPAT_FREEBSD32
1386                 if (wrap32)
1387                         ptrace_lwpinfo_to32(pl, pl32);
1388 #endif
1389                 CTR6(KTR_PTRACE,
1390     "PT_LWPINFO: tid %d (pid %d) event %d flags %#x child pid %d syscall %d",
1391                     td2->td_tid, p->p_pid, pl->pl_event, pl->pl_flags,
1392                     pl->pl_child_pid, pl->pl_syscall_code);
1393                 break;
1394
1395         case PT_GETNUMLWPS:
1396                 CTR2(KTR_PTRACE, "PT_GETNUMLWPS: pid %d: %d threads", p->p_pid,
1397                     p->p_numthreads);
1398                 td->td_retval[0] = p->p_numthreads;
1399                 break;
1400
1401         case PT_GETLWPLIST:
1402                 CTR3(KTR_PTRACE, "PT_GETLWPLIST: pid %d: data %d, actual %d",
1403                     p->p_pid, data, p->p_numthreads);
1404                 if (data <= 0) {
1405                         error = EINVAL;
1406                         break;
1407                 }
1408                 num = imin(p->p_numthreads, data);
1409                 PROC_UNLOCK(p);
1410                 buf = malloc(num * sizeof(lwpid_t), M_TEMP, M_WAITOK);
1411                 tmp = 0;
1412                 PROC_LOCK(p);
1413                 FOREACH_THREAD_IN_PROC(p, td2) {
1414                         if (tmp >= num)
1415                                 break;
1416                         buf[tmp++] = td2->td_tid;
1417                 }
1418                 PROC_UNLOCK(p);
1419                 error = copyout(buf, addr, tmp * sizeof(lwpid_t));
1420                 free(buf, M_TEMP);
1421                 if (!error)
1422                         td->td_retval[0] = tmp;
1423                 PROC_LOCK(p);
1424                 break;
1425
1426         case PT_VM_TIMESTAMP:
1427                 CTR2(KTR_PTRACE, "PT_VM_TIMESTAMP: pid %d: timestamp %d",
1428                     p->p_pid, p->p_vmspace->vm_map.timestamp);
1429                 td->td_retval[0] = p->p_vmspace->vm_map.timestamp;
1430                 break;
1431
1432         case PT_VM_ENTRY:
1433                 PROC_UNLOCK(p);
1434 #ifdef COMPAT_FREEBSD32
1435                 if (wrap32)
1436                         error = ptrace_vm_entry32(td, p, addr);
1437                 else
1438 #endif
1439                 error = ptrace_vm_entry(td, p, addr);
1440                 PROC_LOCK(p);
1441                 break;
1442
1443         default:
1444 #ifdef __HAVE_PTRACE_MACHDEP
1445                 if (req >= PT_FIRSTMACH) {
1446                         PROC_UNLOCK(p);
1447                         error = cpu_ptrace(td2, req, addr, data);
1448                         PROC_LOCK(p);
1449                 } else
1450 #endif
1451                         /* Unknown request. */
1452                         error = EINVAL;
1453                 break;
1454         }
1455
1456 out:
1457         /* Drop our hold on this process now that the request has completed. */
1458         _PRELE(p);
1459 fail:
1460         PROC_UNLOCK(p);
1461         if (proctree_locked)
1462                 sx_xunlock(&proctree_lock);
1463         return (error);
1464 }
1465 #undef PROC_READ
1466 #undef PROC_WRITE
1467
1468 /*
1469  * Stop a process because of a debugging event;
1470  * stay stopped until p->p_step is cleared
1471  * (cleared by PIOCCONT in procfs).
1472  */
1473 void
1474 stopevent(struct proc *p, unsigned int event, unsigned int val)
1475 {
1476
1477         PROC_LOCK_ASSERT(p, MA_OWNED);
1478         p->p_step = 1;
1479         CTR3(KTR_PTRACE, "stopevent: pid %d event %u val %u", p->p_pid, event,
1480             val);
1481         do {
1482                 if (event != S_EXIT)
1483                         p->p_xsig = val;
1484                 p->p_xthread = NULL;
1485                 p->p_stype = event;     /* Which event caused the stop? */
1486                 wakeup(&p->p_stype);    /* Wake up any PIOCWAIT'ing procs */
1487                 msleep(&p->p_step, &p->p_mtx, PWAIT, "stopevent", 0);
1488         } while (p->p_step);
1489 }