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/param.h>
  35 #include <sys/systm.h>
  36 #include <sys/ktr.h>
  37 #include <sys/limits.h>
  38 #include <sys/lock.h>
  39 #include <sys/mutex.h>
  40 #include <sys/reg.h>
  41 #include <sys/syscallsubr.h>
  42 #include <sys/sysent.h>
  43 #include <sys/sysproto.h>
  44 #include <sys/priv.h>
  45 #include <sys/proc.h>
  46 #include <sys/vnode.h>
  47 #include <sys/ptrace.h>
  48 #include <sys/rwlock.h>
  49 #include <sys/sx.h>
  50 #include <sys/malloc.h>
  51 #include <sys/signalvar.h>
  52 #include <sys/caprights.h>
  53 #include <sys/filedesc.h>
  54
  55 #include <security/audit/audit.h>
  56
  57 #include <vm/vm.h>
  58 #include <vm/pmap.h>
  59 #include <vm/vm_extern.h>
  60 #include <vm/vm_map.h>
  61 #include <vm/vm_kern.h>
  62 #include <vm/vm_object.h>
  63 #include <vm/vm_page.h>
  64 #include <vm/vm_param.h>
  65
  66 #ifdef COMPAT_FREEBSD32
  67 #include <sys/procfs.h>
  68 #endif
  69
  70 /* Assert it's safe to unlock a process, e.g. to allocate working memory */
  71 #define PROC_ASSERT_TRACEREQ(p) MPASS(((p)->p_flag2 & P2_PTRACEREQ) != 0)
  72
  73 /*
  74  * Functions implemented using PROC_ACTION():
  75  *
  76  * proc_read_regs(proc, regs)
  77  *      Get the current user-visible register set from the process
  78  *      and copy it into the regs structure (<machine/reg.h>).
  79  *      The process is stopped at the time read_regs is called.
  80  *
  81  * proc_write_regs(proc, regs)
  82  *      Update the current register set from the passed in regs
  83  *      structure.  Take care to avoid clobbering special CPU
  84  *      registers or privileged bits in the PSL.
  85  *      Depending on the architecture this may have fix-up work to do,
  86  *      especially if the IAR or PCW are modified.
  87  *      The process is stopped at the time write_regs is called.
  88  *
  89  * proc_read_fpregs, proc_write_fpregs
  90  *      deal with the floating point register set, otherwise as above.
  91  *
  92  * proc_read_dbregs, proc_write_dbregs
  93  *      deal with the processor debug register set, otherwise as above.
  94  *
  95  * proc_sstep(proc)
  96  *      Arrange for the process to trap after executing a single instruction.
  97  */
  98
  99 #define PROC_ACTION(action) do {                                        \
 100         int error;                                                      \
 101                                                                         \
 102         PROC_LOCK_ASSERT(td->td_proc, MA_OWNED);                        \
 103         if ((td->td_proc->p_flag & P_INMEM) == 0)                       \
 104                 error = EIO;                                            \
 105         else                                                            \
 106                 error = (action);                                       \
 107         return (error);                                                 \
 108 } while (0)
 109
 110 int
 111 proc_read_regs(struct thread *td, struct reg *regs)
 112 {
 113
 114         PROC_ACTION(fill_regs(td, regs));
 115 }
 116
 117 int
 118 proc_write_regs(struct thread *td, struct reg *regs)
 119 {
 120
 121         PROC_ACTION(set_regs(td, regs));
 122 }
 123
 124 int
 125 proc_read_dbregs(struct thread *td, struct dbreg *dbregs)
 126 {
 127
 128         PROC_ACTION(fill_dbregs(td, dbregs));
 129 }
 130
 131 int
 132 proc_write_dbregs(struct thread *td, struct dbreg *dbregs)
 133 {
 134
 135         PROC_ACTION(set_dbregs(td, dbregs));
 136 }
 137
 138 /*
 139  * Ptrace doesn't support fpregs at all, and there are no security holes
 140  * or translations for fpregs, so we can just copy them.
 141  */
 142 int
 143 proc_read_fpregs(struct thread *td, struct fpreg *fpregs)
 144 {
 145
 146         PROC_ACTION(fill_fpregs(td, fpregs));
 147 }
 148
 149 int
 150 proc_write_fpregs(struct thread *td, struct fpreg *fpregs)
 151 {
 152
 153         PROC_ACTION(set_fpregs(td, fpregs));
 154 }
 155
 156 static struct regset *
 157 proc_find_regset(struct thread *td, int note)
 158 {
 159         struct regset **regsetp, **regset_end, *regset;
 160         struct sysentvec *sv;
 161
 162         sv = td->td_proc->p_sysent;
 163         regsetp = sv->sv_regset_begin;
 164         if (regsetp == NULL)
 165                 return (NULL);
 166         regset_end = sv->sv_regset_end;
 167         MPASS(regset_end != NULL);
 168         for (; regsetp < regset_end; regsetp++) {
 169                 regset = *regsetp;
 170                 if (regset->note != note)
 171                         continue;
 172
 173                 return (regset);
 174         }
 175
 176         return (NULL);
 177 }
 178
 179 static int
 180 proc_read_regset(struct thread *td, int note, struct iovec *iov)
 181 {
 182         struct regset *regset;
 183         struct proc *p;
 184         void *buf;
 185         size_t size;
 186         int error;
 187
 188         regset = proc_find_regset(td, note);
 189         if (regset == NULL)
 190                 return (EINVAL);
 191
 192         if (regset->get == NULL)
 193                 return (EINVAL);
 194
 195         size = regset->size;
 196         /*
 197          * The regset is dynamically sized, e.g. the size could change
 198          * depending on the hardware, or may have a per-thread size.
 199          */
 200         if (size == 0) {
 201                 if (!regset->get(regset, td, NULL, &size))
 202                         return (EINVAL);
 203         }
 204
 205         if (iov->iov_base == NULL) {
 206                 iov->iov_len = size;
 207                 if (iov->iov_len == 0)
 208                         return (EINVAL);
 209
 210                 return (0);
 211         }
 212
 213         /* The length is wrong, return an error */
 214         if (iov->iov_len != size)
 215                 return (EINVAL);
 216
 217         error = 0;
 218         p = td->td_proc;
 219
 220         /* Drop the proc lock while allocating the temp buffer */
 221         PROC_ASSERT_TRACEREQ(p);
 222         PROC_UNLOCK(p);
 223         buf = malloc(size, M_TEMP, M_WAITOK);
 224         PROC_LOCK(p);
 225
 226         if (!regset->get(regset, td, buf, &size)) {
 227                 error = EINVAL;
 228         } else {
 229                 KASSERT(size == regset->size || regset->size == 0,
 230                     ("%s: Getter function changed the size", __func__));
 231
 232                 iov->iov_len = size;
 233                 PROC_UNLOCK(p);
 234                 error = copyout(buf, iov->iov_base, size);
 235                 PROC_LOCK(p);
 236         }
 237
 238         free(buf, M_TEMP);
 239
 240         return (error);
 241 }
 242
 243 static int
 244 proc_write_regset(struct thread *td, int note, struct iovec *iov)
 245 {
 246         struct regset *regset;
 247         struct proc *p;
 248         void *buf;
 249         size_t size;
 250         int error;
 251
 252         regset = proc_find_regset(td, note);
 253         if (regset == NULL)
 254                 return (EINVAL);
 255
 256         size = regset->size;
 257         /*
 258          * The regset is dynamically sized, e.g. the size could change
 259          * depending on the hardware, or may have a per-thread size.
 260          */
 261         if (size == 0) {
 262                 if (!regset->get(regset, td, NULL, &size))
 263                         return (EINVAL);
 264         }
 265
 266         /* The length is wrong, return an error */
 267         if (iov->iov_len != size)
 268                 return (EINVAL);
 269
 270         if (regset->set == NULL)
 271                 return (EINVAL);
 272
 273         p = td->td_proc;
 274
 275         /* Drop the proc lock while allocating the temp buffer */
 276         PROC_ASSERT_TRACEREQ(p);
 277         PROC_UNLOCK(p);
 278         buf = malloc(size, M_TEMP, M_WAITOK);
 279         error = copyin(iov->iov_base, buf, size);
 280         PROC_LOCK(p);
 281
 282         if (error == 0) {
 283                 if (!regset->set(regset, td, buf, size)) {
 284                         error = EINVAL;
 285                 }
 286         }
 287
 288         free(buf, M_TEMP);
 289
 290         return (error);
 291 }
 292
 293 #ifdef COMPAT_FREEBSD32
 294 /* For 32 bit binaries, we need to expose the 32 bit regs layouts. */
 295 int
 296 proc_read_regs32(struct thread *td, struct reg32 *regs32)
 297 {
 298
 299         PROC_ACTION(fill_regs32(td, regs32));
 300 }
 301
 302 int
 303 proc_write_regs32(struct thread *td, struct reg32 *regs32)
 304 {
 305
 306         PROC_ACTION(set_regs32(td, regs32));
 307 }
 308
 309 int
 310 proc_read_dbregs32(struct thread *td, struct dbreg32 *dbregs32)
 311 {
 312
 313         PROC_ACTION(fill_dbregs32(td, dbregs32));
 314 }
 315
 316 int
 317 proc_write_dbregs32(struct thread *td, struct dbreg32 *dbregs32)
 318 {
 319
 320         PROC_ACTION(set_dbregs32(td, dbregs32));
 321 }
 322
 323 int
 324 proc_read_fpregs32(struct thread *td, struct fpreg32 *fpregs32)
 325 {
 326
 327         PROC_ACTION(fill_fpregs32(td, fpregs32));
 328 }
 329
 330 int
 331 proc_write_fpregs32(struct thread *td, struct fpreg32 *fpregs32)
 332 {
 333
 334         PROC_ACTION(set_fpregs32(td, fpregs32));
 335 }
 336 #endif
 337
 338 int
 339 proc_sstep(struct thread *td)
 340 {
 341
 342         PROC_ACTION(ptrace_single_step(td));
 343 }
 344
 345 int
 346 proc_rwmem(struct proc *p, struct uio *uio)
 347 {
 348         vm_map_t map;
 349         vm_offset_t pageno;             /* page number */
 350         vm_prot_t reqprot;
 351         int error, fault_flags, page_offset, writing;
 352
 353         /*
 354          * Make sure that the process' vmspace remains live.
 355          */
 356         if (p != curproc)
 357                 PROC_ASSERT_HELD(p);
 358         PROC_LOCK_ASSERT(p, MA_NOTOWNED);
 359
 360         /*
 361          * The map we want...
 362          */
 363         map = &p->p_vmspace->vm_map;
 364
 365         /*
 366          * If we are writing, then we request vm_fault() to create a private
 367          * copy of each page.  Since these copies will not be writeable by the
 368          * process, we must explicity request that they be dirtied.
 369          */
 370         writing = uio->uio_rw == UIO_WRITE;
 371         reqprot = writing ? VM_PROT_COPY | VM_PROT_READ : VM_PROT_READ;
 372         fault_flags = writing ? VM_FAULT_DIRTY : VM_FAULT_NORMAL;
 373
 374         /*
 375          * Only map in one page at a time.  We don't have to, but it
 376          * makes things easier.  This way is trivial - right?
 377          */
 378         do {
 379                 vm_offset_t uva;
 380                 u_int len;
 381                 vm_page_t m;
 382
 383                 uva = (vm_offset_t)uio->uio_offset;
 384
 385                 /*
 386                  * Get the page number of this segment.
 387                  */
 388                 pageno = trunc_page(uva);
 389                 page_offset = uva - pageno;
 390
 391                 /*
 392                  * How many bytes to copy
 393                  */
 394                 len = min(PAGE_SIZE - page_offset, uio->uio_resid);
 395
 396                 /*
 397                  * Fault and hold the page on behalf of the process.
 398                  */
 399                 error = vm_fault(map, pageno, reqprot, fault_flags, &m);
 400                 if (error != KERN_SUCCESS) {
 401                         if (error == KERN_RESOURCE_SHORTAGE)
 402                                 error = ENOMEM;
 403                         else
 404                                 error = EFAULT;
 405                         break;
 406                 }
 407
 408                 /*
 409                  * Now do the i/o move.
 410                  */
 411                 error = uiomove_fromphys(&m, page_offset, len, uio);
 412
 413                 /* Make the I-cache coherent for breakpoints. */
 414                 if (writing && error == 0) {
 415                         vm_map_lock_read(map);
 416                         if (vm_map_check_protection(map, pageno, pageno +
 417                             PAGE_SIZE, VM_PROT_EXECUTE))
 418                                 vm_sync_icache(map, uva, len);
 419                         vm_map_unlock_read(map);
 420                 }
 421
 422                 /*
 423                  * Release the page.
 424                  */
 425                 vm_page_unwire(m, PQ_ACTIVE);
 426
 427         } while (error == 0 && uio->uio_resid > 0);
 428
 429         return (error);
 430 }
 431
 432 static ssize_t
 433 proc_iop(struct thread *td, struct proc *p, vm_offset_t va, void *buf,
 434     size_t len, enum uio_rw rw)
 435 {
 436         struct iovec iov;
 437         struct uio uio;
 438         ssize_t slen;
 439
 440         MPASS(len < SSIZE_MAX);
 441         slen = (ssize_t)len;
 442
 443         iov.iov_base = (caddr_t)buf;
 444         iov.iov_len = len;
 445         uio.uio_iov = &iov;
 446         uio.uio_iovcnt = 1;
 447         uio.uio_offset = va;
 448         uio.uio_resid = slen;
 449         uio.uio_segflg = UIO_SYSSPACE;
 450         uio.uio_rw = rw;
 451         uio.uio_td = td;
 452         proc_rwmem(p, &uio);
 453         if (uio.uio_resid == slen)
 454                 return (-1);
 455         return (slen - uio.uio_resid);
 456 }
 457
 458 ssize_t
 459 proc_readmem(struct thread *td, struct proc *p, vm_offset_t va, void *buf,
 460     size_t len)
 461 {
 462
 463         return (proc_iop(td, p, va, buf, len, UIO_READ));
 464 }
 465
 466 ssize_t
 467 proc_writemem(struct thread *td, struct proc *p, vm_offset_t va, void *buf,
 468     size_t len)
 469 {
 470
 471         return (proc_iop(td, p, va, buf, len, UIO_WRITE));
 472 }
 473
 474 static int
 475 ptrace_vm_entry(struct thread *td, struct proc *p, struct ptrace_vm_entry *pve)
 476 {
 477         struct vattr vattr;
 478         vm_map_t map;
 479         vm_map_entry_t entry;
 480         vm_object_t obj, tobj, lobj;
 481         struct vmspace *vm;
 482         struct vnode *vp;
 483         char *freepath, *fullpath;
 484         u_int pathlen;
 485         int error, index;
 486
 487         error = 0;
 488         obj = NULL;
 489
 490         vm = vmspace_acquire_ref(p);
 491         map = &vm->vm_map;
 492         vm_map_lock_read(map);
 493
 494         do {
 495                 KASSERT((map->header.eflags & MAP_ENTRY_IS_SUB_MAP) == 0,
 496                     ("Submap in map header"));
 497                 index = 0;
 498                 VM_MAP_ENTRY_FOREACH(entry, map) {
 499                         if (index >= pve->pve_entry &&
 500                             (entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0)
 501                                 break;
 502                         index++;
 503                 }
 504                 if (index < pve->pve_entry) {
 505                         error = EINVAL;
 506                         break;
 507                 }
 508                 if (entry == &map->header) {
 509                         error = ENOENT;
 510                         break;
 511                 }
 512
 513                 /* We got an entry. */
 514                 pve->pve_entry = index + 1;
 515                 pve->pve_timestamp = map->timestamp;
 516                 pve->pve_start = entry->start;
 517                 pve->pve_end = entry->end - 1;
 518                 pve->pve_offset = entry->offset;
 519                 pve->pve_prot = entry->protection;
 520
 521                 /* Backing object's path needed? */
 522                 if (pve->pve_pathlen == 0)
 523                         break;
 524
 525                 pathlen = pve->pve_pathlen;
 526                 pve->pve_pathlen = 0;
 527
 528                 obj = entry->object.vm_object;
 529                 if (obj != NULL)
 530                         VM_OBJECT_RLOCK(obj);
 531         } while (0);
 532
 533         vm_map_unlock_read(map);
 534
 535         pve->pve_fsid = VNOVAL;
 536         pve->pve_fileid = VNOVAL;
 537
 538         if (error == 0 && obj != NULL) {
 539                 lobj = obj;
 540                 for (tobj = obj; tobj != NULL; tobj = tobj->backing_object) {
 541                         if (tobj != obj)
 542                                 VM_OBJECT_RLOCK(tobj);
 543                         if (lobj != obj)
 544                                 VM_OBJECT_RUNLOCK(lobj);
 545                         lobj = tobj;
 546                         pve->pve_offset += tobj->backing_object_offset;
 547                 }
 548                 vp = vm_object_vnode(lobj);
 549                 if (vp != NULL)
 550                         vref(vp);
 551                 if (lobj != obj)
 552                         VM_OBJECT_RUNLOCK(lobj);
 553                 VM_OBJECT_RUNLOCK(obj);
 554
 555                 if (vp != NULL) {
 556                         freepath = NULL;
 557                         fullpath = NULL;
 558                         vn_fullpath(vp, &fullpath, &freepath);
 559                         vn_lock(vp, LK_SHARED | LK_RETRY);
 560                         if (VOP_GETATTR(vp, &vattr, td->td_ucred) == 0) {
 561                                 pve->pve_fileid = vattr.va_fileid;
 562                                 pve->pve_fsid = vattr.va_fsid;
 563                         }
 564                         vput(vp);
 565
 566                         if (fullpath != NULL) {
 567                                 pve->pve_pathlen = strlen(fullpath) + 1;
 568                                 if (pve->pve_pathlen <= pathlen) {
 569                                         error = copyout(fullpath, pve->pve_path,
 570                                             pve->pve_pathlen);
 571                                 } else
 572                                         error = ENAMETOOLONG;
 573                         }
 574                         if (freepath != NULL)
 575                                 free(freepath, M_TEMP);
 576                 }
 577         }
 578         vmspace_free(vm);
 579         if (error == 0)
 580                 CTR3(KTR_PTRACE, "PT_VM_ENTRY: pid %d, entry %d, start %p",
 581                     p->p_pid, pve->pve_entry, pve->pve_start);
 582
 583         return (error);
 584 }
 585
 586 /*
 587  * Process debugging system call.
 588  */
 589 #ifndef _SYS_SYSPROTO_H_
 590 struct ptrace_args {
 591         int     req;
 592         pid_t   pid;
 593         caddr_t addr;
 594         int     data;
 595 };
 596 #endif
 597
 598 int
 599 sys_ptrace(struct thread *td, struct ptrace_args *uap)
 600 {
 601         /*
 602          * XXX this obfuscation is to reduce stack usage, but the register
 603          * structs may be too large to put on the stack anyway.
 604          */
 605         union {
 606                 struct ptrace_io_desc piod;
 607                 struct ptrace_lwpinfo pl;
 608                 struct ptrace_vm_entry pve;
 609                 struct ptrace_coredump pc;
 610                 struct ptrace_sc_remote sr;
 611                 struct dbreg dbreg;
 612                 struct fpreg fpreg;
 613                 struct reg reg;
 614                 struct iovec vec;
 615                 syscallarg_t args[nitems(td->td_sa.args)];
 616                 struct ptrace_sc_ret psr;
 617                 int ptevents;
 618         } r;
 619         syscallarg_t pscr_args[nitems(td->td_sa.args)];
 620         void *addr;
 621         int error;
 622
 623         if (!allow_ptrace)
 624                 return (ENOSYS);
 625         error = 0;
 626
 627         AUDIT_ARG_PID(uap->pid);
 628         AUDIT_ARG_CMD(uap->req);
 629         AUDIT_ARG_VALUE(uap->data);
 630         addr = &r;
 631         switch (uap->req) {
 632         case PT_GET_EVENT_MASK:
 633         case PT_LWPINFO:
 634         case PT_GET_SC_ARGS:
 635         case PT_GET_SC_RET:
 636                 break;
 637         case PT_GETREGS:
 638                 bzero(&r.reg, sizeof(r.reg));
 639                 break;
 640         case PT_GETFPREGS:
 641                 bzero(&r.fpreg, sizeof(r.fpreg));
 642                 break;
 643         case PT_GETDBREGS:
 644                 bzero(&r.dbreg, sizeof(r.dbreg));
 645                 break;
 646         case PT_GETREGSET:
 647         case PT_SETREGSET:
 648                 error = copyin(uap->addr, &r.vec, sizeof(r.vec));
 649                 break;
 650         case PT_SETREGS:
 651                 error = copyin(uap->addr, &r.reg, sizeof(r.reg));
 652                 break;
 653         case PT_SETFPREGS:
 654                 error = copyin(uap->addr, &r.fpreg, sizeof(r.fpreg));
 655                 break;
 656         case PT_SETDBREGS:
 657                 error = copyin(uap->addr, &r.dbreg, sizeof(r.dbreg));
 658                 break;
 659         case PT_SET_EVENT_MASK:
 660                 if (uap->data != sizeof(r.ptevents))
 661                         error = EINVAL;
 662                 else
 663                         error = copyin(uap->addr, &r.ptevents, uap->data);
 664                 break;
 665         case PT_IO:
 666                 error = copyin(uap->addr, &r.piod, sizeof(r.piod));
 667                 break;
 668         case PT_VM_ENTRY:
 669                 error = copyin(uap->addr, &r.pve, sizeof(r.pve));
 670                 break;
 671         case PT_COREDUMP:
 672                 if (uap->data != sizeof(r.pc))
 673                         error = EINVAL;
 674                 else
 675                         error = copyin(uap->addr, &r.pc, uap->data);
 676                 break;
 677         case PT_SC_REMOTE:
 678                 if (uap->data != sizeof(r.sr)) {
 679                         error = EINVAL;
 680                         break;
 681                 }
 682                 error = copyin(uap->addr, &r.sr, uap->data);
 683                 if (error != 0)
 684                         break;
 685                 if (r.sr.pscr_nargs > nitems(td->td_sa.args)) {
 686                         error = EINVAL;
 687                         break;
 688                 }
 689                 error = copyin(r.sr.pscr_args, pscr_args,
 690                     sizeof(u_long) * r.sr.pscr_nargs);
 691                 if (error != 0)
 692                         break;
 693                 r.sr.pscr_args = pscr_args;
 694                 break;
 695         default:
 696                 addr = uap->addr;
 697                 break;
 698         }
 699         if (error)
 700                 return (error);
 701
 702         error = kern_ptrace(td, uap->req, uap->pid, addr, uap->data);
 703         if (error)
 704                 return (error);
 705
 706         switch (uap->req) {
 707         case PT_VM_ENTRY:
 708                 error = copyout(&r.pve, uap->addr, sizeof(r.pve));
 709                 break;
 710         case PT_IO:
 711                 error = copyout(&r.piod, uap->addr, sizeof(r.piod));
 712                 break;
 713         case PT_GETREGS:
 714                 error = copyout(&r.reg, uap->addr, sizeof(r.reg));
 715                 break;
 716         case PT_GETFPREGS:
 717                 error = copyout(&r.fpreg, uap->addr, sizeof(r.fpreg));
 718                 break;
 719         case PT_GETDBREGS:
 720                 error = copyout(&r.dbreg, uap->addr, sizeof(r.dbreg));
 721                 break;
 722         case PT_GETREGSET:
 723                 error = copyout(&r.vec, uap->addr, sizeof(r.vec));
 724                 break;
 725         case PT_GET_EVENT_MASK:
 726                 /* NB: The size in uap->data is validated in kern_ptrace(). */
 727                 error = copyout(&r.ptevents, uap->addr, uap->data);
 728                 break;
 729         case PT_LWPINFO:
 730                 /* NB: The size in uap->data is validated in kern_ptrace(). */
 731                 error = copyout(&r.pl, uap->addr, uap->data);
 732                 break;
 733         case PT_GET_SC_ARGS:
 734                 error = copyout(r.args, uap->addr, MIN(uap->data,
 735                     sizeof(r.args)));
 736                 break;
 737         case PT_GET_SC_RET:
 738                 error = copyout(&r.psr, uap->addr, MIN(uap->data,
 739                     sizeof(r.psr)));
 740                 break;
 741         case PT_SC_REMOTE:
 742                 error = copyout(&r.sr.pscr_ret, uap->addr +
 743                     offsetof(struct ptrace_sc_remote, pscr_ret),
 744                     sizeof(r.sr.pscr_ret));
 745                 break;
 746         }
 747
 748         return (error);
 749 }
 750
 751 #ifdef COMPAT_FREEBSD32
 752 /*
 753  *   PROC_READ(regs, td2, addr);
 754  * becomes either:
 755  *   proc_read_regs(td2, addr);
 756  * or
 757  *   proc_read_regs32(td2, addr);
 758  * .. except this is done at runtime.  There is an additional
 759  * complication in that PROC_WRITE disallows 32 bit consumers
 760  * from writing to 64 bit address space targets.
 761  */
 762 #define PROC_READ(w, t, a)      wrap32 ? \
 763         proc_read_ ## w ## 32(t, a) : \
 764         proc_read_ ## w (t, a)
 765 #define PROC_WRITE(w, t, a)     wrap32 ? \
 766         (safe ? proc_write_ ## w ## 32(t, a) : EINVAL ) : \
 767         proc_write_ ## w (t, a)
 768 #else
 769 #define PROC_READ(w, t, a)      proc_read_ ## w (t, a)
 770 #define PROC_WRITE(w, t, a)     proc_write_ ## w (t, a)
 771 #endif
 772
 773 void
 774 proc_set_traced(struct proc *p, bool stop)
 775 {
 776
 777         sx_assert(&proctree_lock, SX_XLOCKED);
 778         PROC_LOCK_ASSERT(p, MA_OWNED);
 779         p->p_flag |= P_TRACED;
 780         if (stop)
 781                 p->p_flag2 |= P2_PTRACE_FSTP;
 782         p->p_ptevents = PTRACE_DEFAULT;
 783 }
 784
 785 void
 786 ptrace_unsuspend(struct proc *p)
 787 {
 788         PROC_LOCK_ASSERT(p, MA_OWNED);
 789
 790         PROC_SLOCK(p);
 791         p->p_flag &= ~(P_STOPPED_TRACE | P_STOPPED_SIG | P_WAITED);
 792         thread_unsuspend(p);
 793         PROC_SUNLOCK(p);
 794         itimer_proc_continue(p);
 795         kqtimer_proc_continue(p);
 796 }
 797
 798 static int
 799 proc_can_ptrace(struct thread *td, struct proc *p)
 800 {
 801         int error;
 802
 803         PROC_LOCK_ASSERT(p, MA_OWNED);
 804
 805         if ((p->p_flag & P_WEXIT) != 0)
 806                 return (ESRCH);
 807
 808         if ((error = p_cansee(td, p)) != 0)
 809                 return (error);
 810         if ((error = p_candebug(td, p)) != 0)
 811                 return (error);
 812
 813         /* not being traced... */
 814         if ((p->p_flag & P_TRACED) == 0)
 815                 return (EPERM);
 816
 817         /* not being traced by YOU */
 818         if (p->p_pptr != td->td_proc)
 819                 return (EBUSY);
 820
 821         /* not currently stopped */
 822         if ((p->p_flag & P_STOPPED_TRACE) == 0 ||
 823             p->p_suspcount != p->p_numthreads  ||
 824             (p->p_flag & P_WAITED) == 0)
 825                 return (EBUSY);
 826
 827         return (0);
 828 }
 829
 830 static struct thread *
 831 ptrace_sel_coredump_thread(struct proc *p)
 832 {
 833         struct thread *td2;
 834
 835         PROC_LOCK_ASSERT(p, MA_OWNED);
 836         MPASS((p->p_flag & P_STOPPED_TRACE) != 0);
 837
 838         FOREACH_THREAD_IN_PROC(p, td2) {
 839                 if ((td2->td_dbgflags & TDB_SSWITCH) != 0)
 840                         return (td2);
 841         }
 842         return (NULL);
 843 }
 844
 845 int
 846 kern_ptrace(struct thread *td, int req, pid_t pid, void *addr, int data)
 847 {
 848         struct iovec iov;
 849         struct uio uio;
 850         struct proc *curp, *p, *pp;
 851         struct thread *td2 = NULL, *td3;
 852         struct ptrace_io_desc *piod = NULL;
 853         struct ptrace_lwpinfo *pl;
 854         struct ptrace_sc_ret *psr;
 855         struct ptrace_sc_remote *pscr;
 856         struct file *fp;
 857         struct ptrace_coredump *pc;
 858         struct thr_coredump_req *tcq;
 859         struct thr_syscall_req *tsr;
 860         int error, num, tmp;
 861         lwpid_t tid = 0, *buf;
 862 #ifdef COMPAT_FREEBSD32
 863         int wrap32 = 0, safe = 0;
 864 #endif
 865         bool proctree_locked, p2_req_set;
 866
 867         curp = td->td_proc;
 868         proctree_locked = false;
 869         p2_req_set = false;
 870
 871         /* Lock proctree before locking the process. */
 872         switch (req) {
 873         case PT_TRACE_ME:
 874         case PT_ATTACH:
 875         case PT_STEP:
 876         case PT_CONTINUE:
 877         case PT_TO_SCE:
 878         case PT_TO_SCX:
 879         case PT_SYSCALL:
 880         case PT_FOLLOW_FORK:
 881         case PT_LWP_EVENTS:
 882         case PT_GET_EVENT_MASK:
 883         case PT_SET_EVENT_MASK:
 884         case PT_DETACH:
 885         case PT_GET_SC_ARGS:
 886                 sx_xlock(&proctree_lock);
 887                 proctree_locked = true;
 888                 break;
 889         default:
 890                 break;
 891         }
 892
 893         if (req == PT_TRACE_ME) {
 894                 p = td->td_proc;
 895                 PROC_LOCK(p);
 896         } else {
 897                 if (pid <= PID_MAX) {
 898                         if ((p = pfind(pid)) == NULL) {
 899                                 if (proctree_locked)
 900                                         sx_xunlock(&proctree_lock);
 901                                 return (ESRCH);
 902                         }
 903                 } else {
 904                         td2 = tdfind(pid, -1);
 905                         if (td2 == NULL) {
 906                                 if (proctree_locked)
 907                                         sx_xunlock(&proctree_lock);
 908                                 return (ESRCH);
 909                         }
 910                         p = td2->td_proc;
 911                         tid = pid;
 912                         pid = p->p_pid;
 913                 }
 914         }
 915         AUDIT_ARG_PROCESS(p);
 916
 917         if ((p->p_flag & P_WEXIT) != 0) {
 918                 error = ESRCH;
 919                 goto fail;
 920         }
 921         if ((error = p_cansee(td, p)) != 0)
 922                 goto fail;
 923
 924         if ((error = p_candebug(td, p)) != 0)
 925                 goto fail;
 926
 927         /*
 928          * System processes can't be debugged.
 929          */
 930         if ((p->p_flag & P_SYSTEM) != 0) {
 931                 error = EINVAL;
 932                 goto fail;
 933         }
 934
 935         if (tid == 0) {
 936                 if ((p->p_flag & P_STOPPED_TRACE) != 0) {
 937                         KASSERT(p->p_xthread != NULL, ("NULL p_xthread"));
 938                         td2 = p->p_xthread;
 939                 } else {
 940                         td2 = FIRST_THREAD_IN_PROC(p);
 941                 }
 942                 tid = td2->td_tid;
 943         }
 944
 945 #ifdef COMPAT_FREEBSD32
 946         /*
 947          * Test if we're a 32 bit client and what the target is.
 948          * Set the wrap controls accordingly.
 949          */
 950         if (SV_CURPROC_FLAG(SV_ILP32)) {
 951                 if (SV_PROC_FLAG(td2->td_proc, SV_ILP32))
 952                         safe = 1;
 953                 wrap32 = 1;
 954         }
 955 #endif
 956         /*
 957          * Permissions check
 958          */
 959         switch (req) {
 960         case PT_TRACE_ME:
 961                 /*
 962                  * Always legal, when there is a parent process which
 963                  * could trace us.  Otherwise, reject.
 964                  */
 965                 if ((p->p_flag & P_TRACED) != 0) {
 966                         error = EBUSY;
 967                         goto fail;
 968                 }
 969                 if (p->p_pptr == initproc) {
 970                         error = EPERM;
 971                         goto fail;
 972                 }
 973                 break;
 974
 975         case PT_ATTACH:
 976                 /* Self */
 977                 if (p == td->td_proc) {
 978                         error = EINVAL;
 979                         goto fail;
 980                 }
 981
 982                 /* Already traced */
 983                 if (p->p_flag & P_TRACED) {
 984                         error = EBUSY;
 985                         goto fail;
 986                 }
 987
 988                 /* Can't trace an ancestor if you're being traced. */
 989                 if (curp->p_flag & P_TRACED) {
 990                         for (pp = curp->p_pptr; pp != NULL; pp = pp->p_pptr) {
 991                                 if (pp == p) {
 992                                         error = EINVAL;
 993                                         goto fail;
 994                                 }
 995                         }
 996                 }
 997
 998                 /* OK */
 999                 break;
1000
1001         case PT_CLEARSTEP:
1002                 /* Allow thread to clear single step for itself */
1003                 if (td->td_tid == tid)
1004                         break;
1005
1006                 /* FALLTHROUGH */
1007         default:
1008                 /*
1009                  * Check for ptrace eligibility before waiting for
1010                  * holds to drain.
1011                  */
1012                 error = proc_can_ptrace(td, p);
1013                 if (error != 0)
1014                         goto fail;
1015
1016                 /*
1017                  * Block parallel ptrace requests.  Most important, do
1018                  * not allow other thread in debugger to continue the
1019                  * debuggee until coredump finished.
1020                  */
1021                 while ((p->p_flag2 & P2_PTRACEREQ) != 0) {
1022                         if (proctree_locked)
1023                                 sx_xunlock(&proctree_lock);
1024                         error = msleep(&p->p_flag2, &p->p_mtx, PPAUSE | PCATCH |
1025                             (proctree_locked ? PDROP : 0), "pptrace", 0);
1026                         if (proctree_locked) {
1027                                 sx_xlock(&proctree_lock);
1028                                 PROC_LOCK(p);
1029                         }
1030                         if (error == 0 && td2->td_proc != p)
1031                                 error = ESRCH;
1032                         if (error == 0)
1033                                 error = proc_can_ptrace(td, p);
1034                         if (error != 0)
1035                                 goto fail;
1036                 }
1037
1038                 /* Ok */
1039                 break;
1040         }
1041
1042         /*
1043          * Keep this process around and request parallel ptrace()
1044          * request to wait until we finish this request.
1045          */
1046         MPASS((p->p_flag2 & P2_PTRACEREQ) == 0);
1047         p->p_flag2 |= P2_PTRACEREQ;
1048         p2_req_set = true;
1049         _PHOLD(p);
1050
1051         /*
1052          * Actually do the requests
1053          */
1054
1055         td->td_retval[0] = 0;
1056
1057         switch (req) {
1058         case PT_TRACE_ME:
1059                 /* set my trace flag and "owner" so it can read/write me */
1060                 proc_set_traced(p, false);
1061                 if (p->p_flag & P_PPWAIT)
1062                         p->p_flag |= P_PPTRACE;
1063                 CTR1(KTR_PTRACE, "PT_TRACE_ME: pid %d", p->p_pid);
1064                 break;
1065
1066         case PT_ATTACH:
1067                 /* security check done above */
1068                 /*
1069                  * It would be nice if the tracing relationship was separate
1070                  * from the parent relationship but that would require
1071                  * another set of links in the proc struct or for "wait"
1072                  * to scan the entire proc table.  To make life easier,
1073                  * we just re-parent the process we're trying to trace.
1074                  * The old parent is remembered so we can put things back
1075                  * on a "detach".
1076                  */
1077                 proc_set_traced(p, true);
1078                 proc_reparent(p, td->td_proc, false);
1079                 CTR2(KTR_PTRACE, "PT_ATTACH: pid %d, oppid %d", p->p_pid,
1080                     p->p_oppid);
1081
1082                 sx_xunlock(&proctree_lock);
1083                 proctree_locked = false;
1084                 MPASS(p->p_xthread == NULL);
1085                 MPASS((p->p_flag & P_STOPPED_TRACE) == 0);
1086
1087                 /*
1088                  * If already stopped due to a stop signal, clear the
1089                  * existing stop before triggering a traced SIGSTOP.
1090                  */
1091                 if ((p->p_flag & P_STOPPED_SIG) != 0) {
1092                         PROC_SLOCK(p);
1093                         p->p_flag &= ~(P_STOPPED_SIG | P_WAITED);
1094                         thread_unsuspend(p);
1095                         PROC_SUNLOCK(p);
1096                 }
1097
1098                 kern_psignal(p, SIGSTOP);
1099                 break;
1100
1101         case PT_CLEARSTEP:
1102                 CTR2(KTR_PTRACE, "PT_CLEARSTEP: tid %d (pid %d)", td2->td_tid,
1103                     p->p_pid);
1104                 error = ptrace_clear_single_step(td2);
1105                 break;
1106
1107         case PT_SETSTEP:
1108                 CTR2(KTR_PTRACE, "PT_SETSTEP: tid %d (pid %d)", td2->td_tid,
1109                     p->p_pid);
1110                 error = ptrace_single_step(td2);
1111                 break;
1112
1113         case PT_SUSPEND:
1114                 CTR2(KTR_PTRACE, "PT_SUSPEND: tid %d (pid %d)", td2->td_tid,
1115                     p->p_pid);
1116                 td2->td_dbgflags |= TDB_SUSPEND;
1117                 ast_sched(td2, TDA_SUSPEND);
1118                 break;
1119
1120         case PT_RESUME:
1121                 CTR2(KTR_PTRACE, "PT_RESUME: tid %d (pid %d)", td2->td_tid,
1122                     p->p_pid);
1123                 td2->td_dbgflags &= ~TDB_SUSPEND;
1124                 break;
1125
1126         case PT_FOLLOW_FORK:
1127                 CTR3(KTR_PTRACE, "PT_FOLLOW_FORK: pid %d %s -> %s", p->p_pid,
1128                     p->p_ptevents & PTRACE_FORK ? "enabled" : "disabled",
1129                     data ? "enabled" : "disabled");
1130                 if (data)
1131                         p->p_ptevents |= PTRACE_FORK;
1132                 else
1133                         p->p_ptevents &= ~PTRACE_FORK;
1134                 break;
1135
1136         case PT_LWP_EVENTS:
1137                 CTR3(KTR_PTRACE, "PT_LWP_EVENTS: pid %d %s -> %s", p->p_pid,
1138                     p->p_ptevents & PTRACE_LWP ? "enabled" : "disabled",
1139                     data ? "enabled" : "disabled");
1140                 if (data)
1141                         p->p_ptevents |= PTRACE_LWP;
1142                 else
1143                         p->p_ptevents &= ~PTRACE_LWP;
1144                 break;
1145
1146         case PT_GET_EVENT_MASK:
1147                 if (data != sizeof(p->p_ptevents)) {
1148                         error = EINVAL;
1149                         break;
1150                 }
1151                 CTR2(KTR_PTRACE, "PT_GET_EVENT_MASK: pid %d mask %#x", p->p_pid,
1152                     p->p_ptevents);
1153                 *(int *)addr = p->p_ptevents;
1154                 break;
1155
1156         case PT_SET_EVENT_MASK:
1157                 if (data != sizeof(p->p_ptevents)) {
1158                         error = EINVAL;
1159                         break;
1160                 }
1161                 tmp = *(int *)addr;
1162                 if ((tmp & ~(PTRACE_EXEC | PTRACE_SCE | PTRACE_SCX |
1163                     PTRACE_FORK | PTRACE_LWP | PTRACE_VFORK)) != 0) {
1164                         error = EINVAL;
1165                         break;
1166                 }
1167                 CTR3(KTR_PTRACE, "PT_SET_EVENT_MASK: pid %d mask %#x -> %#x",
1168                     p->p_pid, p->p_ptevents, tmp);
1169                 p->p_ptevents = tmp;
1170                 break;
1171
1172         case PT_GET_SC_ARGS:
1173                 CTR1(KTR_PTRACE, "PT_GET_SC_ARGS: pid %d", p->p_pid);
1174                 if ((td2->td_dbgflags & (TDB_SCE | TDB_SCX)) == 0
1175 #ifdef COMPAT_FREEBSD32
1176                     || (wrap32 && !safe)
1177 #endif
1178                     ) {
1179                         error = EINVAL;
1180                         break;
1181                 }
1182                 bzero(addr, sizeof(td2->td_sa.args));
1183                 /* See the explanation in linux_ptrace_get_syscall_info(). */
1184                 bcopy(td2->td_sa.args, addr, SV_PROC_ABI(td->td_proc) ==
1185                     SV_ABI_LINUX ? sizeof(td2->td_sa.args) :
1186                     td2->td_sa.callp->sy_narg * sizeof(syscallarg_t));
1187                 break;
1188
1189         case PT_GET_SC_RET:
1190                 if ((td2->td_dbgflags & (TDB_SCX)) == 0
1191 #ifdef COMPAT_FREEBSD32
1192                     || (wrap32 && !safe)
1193 #endif
1194                     ) {
1195                         error = EINVAL;
1196                         break;
1197                 }
1198                 psr = addr;
1199                 bzero(psr, sizeof(*psr));
1200                 psr->sr_error = td2->td_errno;
1201                 if (psr->sr_error == 0) {
1202                         psr->sr_retval[0] = td2->td_retval[0];
1203                         psr->sr_retval[1] = td2->td_retval[1];
1204                 }
1205                 CTR4(KTR_PTRACE,
1206                     "PT_GET_SC_RET: pid %d error %d retval %#lx,%#lx",
1207                     p->p_pid, psr->sr_error, psr->sr_retval[0],
1208                     psr->sr_retval[1]);
1209                 break;
1210
1211         case PT_STEP:
1212         case PT_CONTINUE:
1213         case PT_TO_SCE:
1214         case PT_TO_SCX:
1215         case PT_SYSCALL:
1216         case PT_DETACH:
1217                 /* Zero means do not send any signal */
1218                 if (data < 0 || data > _SIG_MAXSIG) {
1219                         error = EINVAL;
1220                         break;
1221                 }
1222
1223                 switch (req) {
1224                 case PT_STEP:
1225                         CTR3(KTR_PTRACE, "PT_STEP: tid %d (pid %d), sig = %d",
1226                             td2->td_tid, p->p_pid, data);
1227                         error = ptrace_single_step(td2);
1228                         if (error)
1229                                 goto out;
1230                         break;
1231                 case PT_CONTINUE:
1232                 case PT_TO_SCE:
1233                 case PT_TO_SCX:
1234                 case PT_SYSCALL:
1235                         if (addr != (void *)1) {
1236                                 error = ptrace_set_pc(td2,
1237                                     (u_long)(uintfptr_t)addr);
1238                                 if (error)
1239                                         goto out;
1240                         }
1241                         switch (req) {
1242                         case PT_TO_SCE:
1243                                 p->p_ptevents |= PTRACE_SCE;
1244                                 CTR4(KTR_PTRACE,
1245                     "PT_TO_SCE: pid %d, events = %#x, PC = %#lx, sig = %d",
1246                                     p->p_pid, p->p_ptevents,
1247                                     (u_long)(uintfptr_t)addr, data);
1248                                 break;
1249                         case PT_TO_SCX:
1250                                 p->p_ptevents |= PTRACE_SCX;
1251                                 CTR4(KTR_PTRACE,
1252                     "PT_TO_SCX: pid %d, events = %#x, PC = %#lx, sig = %d",
1253                                     p->p_pid, p->p_ptevents,
1254                                     (u_long)(uintfptr_t)addr, data);
1255                                 break;
1256                         case PT_SYSCALL:
1257                                 p->p_ptevents |= PTRACE_SYSCALL;
1258                                 CTR4(KTR_PTRACE,
1259                     "PT_SYSCALL: pid %d, events = %#x, PC = %#lx, sig = %d",
1260                                     p->p_pid, p->p_ptevents,
1261                                     (u_long)(uintfptr_t)addr, data);
1262                                 break;
1263                         case PT_CONTINUE:
1264                                 CTR3(KTR_PTRACE,
1265                                     "PT_CONTINUE: pid %d, PC = %#lx, sig = %d",
1266                                     p->p_pid, (u_long)(uintfptr_t)addr, data);
1267                                 break;
1268                         }
1269                         break;
1270                 case PT_DETACH:
1271                         /*
1272                          * Clear P_TRACED before reparenting
1273                          * a detached process back to its original
1274                          * parent.  Otherwise the debugee will be set
1275                          * as an orphan of the debugger.
1276                          */
1277                         p->p_flag &= ~(P_TRACED | P_WAITED);
1278
1279                         /*
1280                          * Reset the process parent.
1281                          */
1282                         if (p->p_oppid != p->p_pptr->p_pid) {
1283                                 PROC_LOCK(p->p_pptr);
1284                                 sigqueue_take(p->p_ksi);
1285                                 PROC_UNLOCK(p->p_pptr);
1286
1287                                 pp = proc_realparent(p);
1288                                 proc_reparent(p, pp, false);
1289                                 if (pp == initproc)
1290                                         p->p_sigparent = SIGCHLD;
1291                                 CTR3(KTR_PTRACE,
1292                             "PT_DETACH: pid %d reparented to pid %d, sig %d",
1293                                     p->p_pid, pp->p_pid, data);
1294                         } else {
1295                                 CTR2(KTR_PTRACE, "PT_DETACH: pid %d, sig %d",
1296                                     p->p_pid, data);
1297                         }
1298
1299                         p->p_ptevents = 0;
1300                         FOREACH_THREAD_IN_PROC(p, td3) {
1301                                 if ((td3->td_dbgflags & TDB_FSTP) != 0) {
1302                                         sigqueue_delete(&td3->td_sigqueue,
1303                                             SIGSTOP);
1304                                 }
1305                                 td3->td_dbgflags &= ~(TDB_XSIG | TDB_FSTP |
1306                                     TDB_SUSPEND | TDB_BORN);
1307                         }
1308
1309                         if ((p->p_flag2 & P2_PTRACE_FSTP) != 0) {
1310                                 sigqueue_delete(&p->p_sigqueue, SIGSTOP);
1311                                 p->p_flag2 &= ~P2_PTRACE_FSTP;
1312                         }
1313
1314                         /* should we send SIGCHLD? */
1315                         /* childproc_continued(p); */
1316                         break;
1317                 }
1318
1319                 sx_xunlock(&proctree_lock);
1320                 proctree_locked = false;
1321
1322         sendsig:
1323                 MPASS(!proctree_locked);
1324
1325                 /*
1326                  * Clear the pending event for the thread that just
1327                  * reported its event (p_xthread).  This may not be
1328                  * the thread passed to PT_CONTINUE, PT_STEP, etc. if
1329                  * the debugger is resuming a different thread.
1330                  *
1331                  * Deliver any pending signal via the reporting thread.
1332                  */
1333                 MPASS(p->p_xthread != NULL);
1334                 p->p_xthread->td_dbgflags &= ~TDB_XSIG;
1335                 p->p_xthread->td_xsig = data;
1336                 p->p_xthread = NULL;
1337                 p->p_xsig = data;
1338
1339                 /*
1340                  * P_WKILLED is insurance that a PT_KILL/SIGKILL
1341                  * always works immediately, even if another thread is
1342                  * unsuspended first and attempts to handle a
1343                  * different signal or if the POSIX.1b style signal
1344                  * queue cannot accommodate any new signals.
1345                  */
1346                 if (data == SIGKILL)
1347                         proc_wkilled(p);
1348
1349                 /*
1350                  * Unsuspend all threads.  To leave a thread
1351                  * suspended, use PT_SUSPEND to suspend it before
1352                  * continuing the process.
1353                  */
1354                 ptrace_unsuspend(p);
1355                 break;
1356
1357         case PT_WRITE_I:
1358         case PT_WRITE_D:
1359                 td2->td_dbgflags |= TDB_USERWR;
1360                 PROC_UNLOCK(p);
1361                 error = 0;
1362                 if (proc_writemem(td, p, (off_t)(uintptr_t)addr, &data,
1363                     sizeof(int)) != sizeof(int))
1364                         error = ENOMEM;
1365                 else
1366                         CTR3(KTR_PTRACE, "PT_WRITE: pid %d: %p <= %#x",
1367                             p->p_pid, addr, data);
1368                 PROC_LOCK(p);
1369                 break;
1370
1371         case PT_READ_I:
1372         case PT_READ_D:
1373                 PROC_UNLOCK(p);
1374                 error = tmp = 0;
1375                 if (proc_readmem(td, p, (off_t)(uintptr_t)addr, &tmp,
1376                     sizeof(int)) != sizeof(int))
1377                         error = ENOMEM;
1378                 else
1379                         CTR3(KTR_PTRACE, "PT_READ: pid %d: %p >= %#x",
1380                             p->p_pid, addr, tmp);
1381                 td->td_retval[0] = tmp;
1382                 PROC_LOCK(p);
1383                 break;
1384
1385         case PT_IO:
1386                 piod = addr;
1387                 iov.iov_base = piod->piod_addr;
1388                 iov.iov_len = piod->piod_len;
1389                 uio.uio_offset = (off_t)(uintptr_t)piod->piod_offs;
1390                 uio.uio_resid = piod->piod_len;
1391                 uio.uio_iov = &iov;
1392                 uio.uio_iovcnt = 1;
1393                 uio.uio_segflg = UIO_USERSPACE;
1394                 uio.uio_td = td;
1395                 switch (piod->piod_op) {
1396                 case PIOD_READ_D:
1397                 case PIOD_READ_I:
1398                         CTR3(KTR_PTRACE, "PT_IO: pid %d: READ (%p, %#x)",
1399                             p->p_pid, (uintptr_t)uio.uio_offset, uio.uio_resid);
1400                         uio.uio_rw = UIO_READ;
1401                         break;
1402                 case PIOD_WRITE_D:
1403                 case PIOD_WRITE_I:
1404                         CTR3(KTR_PTRACE, "PT_IO: pid %d: WRITE (%p, %#x)",
1405                             p->p_pid, (uintptr_t)uio.uio_offset, uio.uio_resid);
1406                         td2->td_dbgflags |= TDB_USERWR;
1407                         uio.uio_rw = UIO_WRITE;
1408                         break;
1409                 default:
1410                         error = EINVAL;
1411                         goto out;
1412                 }
1413                 PROC_UNLOCK(p);
1414                 error = proc_rwmem(p, &uio);
1415                 piod->piod_len -= uio.uio_resid;
1416                 PROC_LOCK(p);
1417                 break;
1418
1419         case PT_KILL:
1420                 CTR1(KTR_PTRACE, "PT_KILL: pid %d", p->p_pid);
1421                 data = SIGKILL;
1422                 goto sendsig;   /* in PT_CONTINUE above */
1423
1424         case PT_SETREGS:
1425                 CTR2(KTR_PTRACE, "PT_SETREGS: tid %d (pid %d)", td2->td_tid,
1426                     p->p_pid);
1427                 td2->td_dbgflags |= TDB_USERWR;
1428                 error = PROC_WRITE(regs, td2, addr);
1429                 break;
1430
1431         case PT_GETREGS:
1432                 CTR2(KTR_PTRACE, "PT_GETREGS: tid %d (pid %d)", td2->td_tid,
1433                     p->p_pid);
1434                 error = PROC_READ(regs, td2, addr);
1435                 break;
1436
1437         case PT_SETFPREGS:
1438                 CTR2(KTR_PTRACE, "PT_SETFPREGS: tid %d (pid %d)", td2->td_tid,
1439                     p->p_pid);
1440                 td2->td_dbgflags |= TDB_USERWR;
1441                 error = PROC_WRITE(fpregs, td2, addr);
1442                 break;
1443
1444         case PT_GETFPREGS:
1445                 CTR2(KTR_PTRACE, "PT_GETFPREGS: tid %d (pid %d)", td2->td_tid,
1446                     p->p_pid);
1447                 error = PROC_READ(fpregs, td2, addr);
1448                 break;
1449
1450         case PT_SETDBREGS:
1451                 CTR2(KTR_PTRACE, "PT_SETDBREGS: tid %d (pid %d)", td2->td_tid,
1452                     p->p_pid);
1453                 td2->td_dbgflags |= TDB_USERWR;
1454                 error = PROC_WRITE(dbregs, td2, addr);
1455                 break;
1456
1457         case PT_GETDBREGS:
1458                 CTR2(KTR_PTRACE, "PT_GETDBREGS: tid %d (pid %d)", td2->td_tid,
1459                     p->p_pid);
1460                 error = PROC_READ(dbregs, td2, addr);
1461                 break;
1462
1463         case PT_SETREGSET:
1464                 CTR2(KTR_PTRACE, "PT_SETREGSET: tid %d (pid %d)", td2->td_tid,
1465                     p->p_pid);
1466                 error = proc_write_regset(td2, data, addr);
1467                 break;
1468
1469         case PT_GETREGSET:
1470                 CTR2(KTR_PTRACE, "PT_GETREGSET: tid %d (pid %d)", td2->td_tid,
1471                     p->p_pid);
1472                 error = proc_read_regset(td2, data, addr);
1473                 break;
1474
1475         case PT_LWPINFO:
1476                 if (data <= 0 || data > sizeof(*pl)) {
1477                         error = EINVAL;
1478                         break;
1479                 }
1480                 pl = addr;
1481                 bzero(pl, sizeof(*pl));
1482                 pl->pl_lwpid = td2->td_tid;
1483                 pl->pl_event = PL_EVENT_NONE;
1484                 pl->pl_flags = 0;
1485                 if (td2->td_dbgflags & TDB_XSIG) {
1486                         pl->pl_event = PL_EVENT_SIGNAL;
1487                         if (td2->td_si.si_signo != 0 &&
1488                             data >= offsetof(struct ptrace_lwpinfo, pl_siginfo)
1489                             + sizeof(pl->pl_siginfo)){
1490                                 pl->pl_flags |= PL_FLAG_SI;
1491                                 pl->pl_siginfo = td2->td_si;
1492                         }
1493                 }
1494                 if (td2->td_dbgflags & TDB_SCE)
1495                         pl->pl_flags |= PL_FLAG_SCE;
1496                 else if (td2->td_dbgflags & TDB_SCX)
1497                         pl->pl_flags |= PL_FLAG_SCX;
1498                 if (td2->td_dbgflags & TDB_EXEC)
1499                         pl->pl_flags |= PL_FLAG_EXEC;
1500                 if (td2->td_dbgflags & TDB_FORK) {
1501                         pl->pl_flags |= PL_FLAG_FORKED;
1502                         pl->pl_child_pid = td2->td_dbg_forked;
1503                         if (td2->td_dbgflags & TDB_VFORK)
1504                                 pl->pl_flags |= PL_FLAG_VFORKED;
1505                 } else if ((td2->td_dbgflags & (TDB_SCX | TDB_VFORK)) ==
1506                     TDB_VFORK)
1507                         pl->pl_flags |= PL_FLAG_VFORK_DONE;
1508                 if (td2->td_dbgflags & TDB_CHILD)
1509                         pl->pl_flags |= PL_FLAG_CHILD;
1510                 if (td2->td_dbgflags & TDB_BORN)
1511                         pl->pl_flags |= PL_FLAG_BORN;
1512                 if (td2->td_dbgflags & TDB_EXIT)
1513                         pl->pl_flags |= PL_FLAG_EXITED;
1514                 pl->pl_sigmask = td2->td_sigmask;
1515                 pl->pl_siglist = td2->td_siglist;
1516                 strcpy(pl->pl_tdname, td2->td_name);
1517                 if ((td2->td_dbgflags & (TDB_SCE | TDB_SCX)) != 0) {
1518                         pl->pl_syscall_code = td2->td_sa.code;
1519                         pl->pl_syscall_narg = td2->td_sa.callp->sy_narg;
1520                 } else {
1521                         pl->pl_syscall_code = 0;
1522                         pl->pl_syscall_narg = 0;
1523                 }
1524                 CTR6(KTR_PTRACE,
1525     "PT_LWPINFO: tid %d (pid %d) event %d flags %#x child pid %d syscall %d",
1526                     td2->td_tid, p->p_pid, pl->pl_event, pl->pl_flags,
1527                     pl->pl_child_pid, pl->pl_syscall_code);
1528                 break;
1529
1530         case PT_GETNUMLWPS:
1531                 CTR2(KTR_PTRACE, "PT_GETNUMLWPS: pid %d: %d threads", p->p_pid,
1532                     p->p_numthreads);
1533                 td->td_retval[0] = p->p_numthreads;
1534                 break;
1535
1536         case PT_GETLWPLIST:
1537                 CTR3(KTR_PTRACE, "PT_GETLWPLIST: pid %d: data %d, actual %d",
1538                     p->p_pid, data, p->p_numthreads);
1539                 if (data <= 0) {
1540                         error = EINVAL;
1541                         break;
1542                 }
1543                 num = imin(p->p_numthreads, data);
1544                 PROC_UNLOCK(p);
1545                 buf = malloc(num * sizeof(lwpid_t), M_TEMP, M_WAITOK);
1546                 tmp = 0;
1547                 PROC_LOCK(p);
1548                 FOREACH_THREAD_IN_PROC(p, td2) {
1549                         if (tmp >= num)
1550                                 break;
1551                         buf[tmp++] = td2->td_tid;
1552                 }
1553                 PROC_UNLOCK(p);
1554                 error = copyout(buf, addr, tmp * sizeof(lwpid_t));
1555                 free(buf, M_TEMP);
1556                 if (!error)
1557                         td->td_retval[0] = tmp;
1558                 PROC_LOCK(p);
1559                 break;
1560
1561         case PT_VM_TIMESTAMP:
1562                 CTR2(KTR_PTRACE, "PT_VM_TIMESTAMP: pid %d: timestamp %d",
1563                     p->p_pid, p->p_vmspace->vm_map.timestamp);
1564                 td->td_retval[0] = p->p_vmspace->vm_map.timestamp;
1565                 break;
1566
1567         case PT_VM_ENTRY:
1568                 PROC_UNLOCK(p);
1569                 error = ptrace_vm_entry(td, p, addr);
1570                 PROC_LOCK(p);
1571                 break;
1572
1573         case PT_COREDUMP:
1574                 pc = addr;
1575                 CTR2(KTR_PTRACE, "PT_COREDUMP: pid %d, fd %d",
1576                     p->p_pid, pc->pc_fd);
1577
1578                 if ((pc->pc_flags & ~(PC_COMPRESS | PC_ALL)) != 0) {
1579                         error = EINVAL;
1580                         break;
1581                 }
1582                 PROC_UNLOCK(p);
1583
1584                 tcq = malloc(sizeof(*tcq), M_TEMP, M_WAITOK | M_ZERO);
1585                 fp = NULL;
1586                 error = fget_write(td, pc->pc_fd, &cap_write_rights, &fp);
1587                 if (error != 0)
1588                         goto coredump_cleanup_nofp;
1589                 if (fp->f_type != DTYPE_VNODE || fp->f_vnode->v_type != VREG) {
1590                         error = EPIPE;
1591                         goto coredump_cleanup;
1592                 }
1593
1594                 PROC_LOCK(p);
1595                 error = proc_can_ptrace(td, p);
1596                 if (error != 0)
1597                         goto coredump_cleanup_locked;
1598
1599                 td2 = ptrace_sel_coredump_thread(p);
1600                 if (td2 == NULL) {
1601                         error = EBUSY;
1602                         goto coredump_cleanup_locked;
1603                 }
1604                 KASSERT((td2->td_dbgflags & (TDB_COREDUMPREQ |
1605                     TDB_SCREMOTEREQ)) == 0,
1606                     ("proc %d tid %d req coredump", p->p_pid, td2->td_tid));
1607
1608                 tcq->tc_vp = fp->f_vnode;
1609                 tcq->tc_limit = pc->pc_limit == 0 ? OFF_MAX : pc->pc_limit;
1610                 tcq->tc_flags = SVC_PT_COREDUMP;
1611                 if ((pc->pc_flags & PC_COMPRESS) == 0)
1612                         tcq->tc_flags |= SVC_NOCOMPRESS;
1613                 if ((pc->pc_flags & PC_ALL) != 0)
1614                         tcq->tc_flags |= SVC_ALL;
1615                 td2->td_remotereq = tcq;
1616                 td2->td_dbgflags |= TDB_COREDUMPREQ;
1617                 thread_run_flash(td2);
1618                 while ((td2->td_dbgflags & TDB_COREDUMPREQ) != 0)
1619                         msleep(p, &p->p_mtx, PPAUSE, "crdmp", 0);
1620                 error = tcq->tc_error;
1621 coredump_cleanup_locked:
1622                 PROC_UNLOCK(p);
1623 coredump_cleanup:
1624                 fdrop(fp, td);
1625 coredump_cleanup_nofp:
1626                 free(tcq, M_TEMP);
1627                 PROC_LOCK(p);
1628                 break;
1629
1630         case PT_SC_REMOTE:
1631                 pscr = addr;
1632                 CTR2(KTR_PTRACE, "PT_SC_REMOTE: pid %d, syscall %d",
1633                     p->p_pid, pscr->pscr_syscall);
1634                 if ((td2->td_dbgflags & TDB_BOUNDARY) == 0) {
1635                         error = EBUSY;
1636                         break;
1637                 }
1638                 PROC_UNLOCK(p);
1639                 MPASS(pscr->pscr_nargs <= nitems(td->td_sa.args));
1640
1641                 tsr = malloc(sizeof(struct thr_syscall_req), M_TEMP,
1642                     M_WAITOK | M_ZERO);
1643
1644                 tsr->ts_sa.code = pscr->pscr_syscall;
1645                 tsr->ts_nargs = pscr->pscr_nargs;
1646                 memcpy(&tsr->ts_sa.args, pscr->pscr_args,
1647                     sizeof(syscallarg_t) * tsr->ts_nargs);
1648
1649                 PROC_LOCK(p);
1650                 error = proc_can_ptrace(td, p);
1651                 if (error != 0) {
1652                         free(tsr, M_TEMP);
1653                         break;
1654                 }
1655                 if (td2->td_proc != p) {
1656                         free(tsr, M_TEMP);
1657                         error = ESRCH;
1658                         break;
1659                 }
1660                 KASSERT((td2->td_dbgflags & (TDB_COREDUMPREQ |
1661                     TDB_SCREMOTEREQ)) == 0,
1662                     ("proc %d tid %d req coredump", p->p_pid, td2->td_tid));
1663
1664                 td2->td_remotereq = tsr;
1665                 td2->td_dbgflags |= TDB_SCREMOTEREQ;
1666                 thread_run_flash(td2);
1667                 while ((td2->td_dbgflags & TDB_SCREMOTEREQ) != 0)
1668                         msleep(p, &p->p_mtx, PPAUSE, "pscrx", 0);
1669                 error = 0;
1670                 memcpy(&pscr->pscr_ret, &tsr->ts_ret, sizeof(tsr->ts_ret));
1671                 free(tsr, M_TEMP);
1672                 break;
1673
1674         default:
1675 #ifdef __HAVE_PTRACE_MACHDEP
1676                 if (req >= PT_FIRSTMACH) {
1677                         PROC_UNLOCK(p);
1678                         error = cpu_ptrace(td2, req, addr, data);
1679                         PROC_LOCK(p);
1680                 } else
1681 #endif
1682                         /* Unknown request. */
1683                         error = EINVAL;
1684                 break;
1685         }
1686 out:
1687         /* Drop our hold on this process now that the request has completed. */
1688         _PRELE(p);
1689 fail:
1690         if (p2_req_set) {
1691                 if ((p->p_flag2 & P2_PTRACEREQ) != 0)
1692                         wakeup(&p->p_flag2);
1693                 p->p_flag2 &= ~P2_PTRACEREQ;
1694         }
1695         PROC_UNLOCK(p);
1696         if (proctree_locked)
1697                 sx_xunlock(&proctree_lock);
1698         return (error);
1699 }
1700 #undef PROC_READ
1701 #undef PROC_WRITE