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