sys/kern/sys_process.c

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