sys/kern/sys_process.c

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