sys/kern/sys_process.c

   1 /*-
   2  * SPDX-License-Identifier: BSD-4-Clause
   3  *
   4  * Copyright (c) 1994, Sean Eric Fagan
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. All advertising materials mentioning features or use of this software
  16  *    must display the following acknowledgement:
  17  *      This product includes software developed by Sean Eric Fagan.
  18  * 4. The name of the author may not be used to endorse or promote products
  19  *    derived from this software without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 #include <sys/cdefs.h>
  35 __FBSDID("$FreeBSD$");
  36
  37 #include <sys/param.h>
  38 #include <sys/systm.h>
  39 #include <sys/ktr.h>
  40 #include <sys/lock.h>
  41 #include <sys/mutex.h>
  42 #include <sys/syscallsubr.h>
  43 #include <sys/sysent.h>
  44 #include <sys/sysproto.h>
  45 #include <sys/pioctl.h>
  46 #include <sys/priv.h>
  47 #include <sys/proc.h>
  48 #include <sys/vnode.h>
  49 #include <sys/ptrace.h>
  50 #include <sys/rwlock.h>
  51 #include <sys/sx.h>
  52 #include <sys/malloc.h>
  53 #include <sys/signalvar.h>
  54
  55 #include <machine/reg.h>
  56
  57 #include <security/audit/audit.h>
  58
  59 #include <vm/vm.h>
  60 #include <vm/pmap.h>
  61 #include <vm/vm_extern.h>
  62 #include <vm/vm_map.h>
  63 #include <vm/vm_kern.h>
  64 #include <vm/vm_object.h>
  65 #include <vm/vm_page.h>
  66 #include <vm/vm_param.h>
  67
  68 #ifdef COMPAT_FREEBSD32
  69 #include <sys/procfs.h>
  70 #include <compat/freebsd32/freebsd32_signal.h>
  71
  72 struct ptrace_io_desc32 {
  73         int             piod_op;
  74         uint32_t        piod_offs;
  75         uint32_t        piod_addr;
  76         uint32_t        piod_len;
  77 };
  78
  79 struct ptrace_sc_ret32 {
  80         uint32_t        sr_retval[2];
  81         int             sr_error;
  82 };
  83
  84 struct ptrace_vm_entry32 {
  85         int             pve_entry;
  86         int             pve_timestamp;
  87         uint32_t        pve_start;
  88         uint32_t        pve_end;
  89         uint32_t        pve_offset;
  90         u_int           pve_prot;
  91         u_int           pve_pathlen;
  92         int32_t         pve_fileid;
  93         u_int           pve_fsid;
  94         uint32_t        pve_path;
  95 };
  96 #endif
  97
  98 /*
  99  * Functions implemented using PROC_ACTION():
 100  *
 101  * proc_read_regs(proc, regs)
 102  *      Get the current user-visible register set from the process
 103  *      and copy it into the regs structure (<machine/reg.h>).
 104  *      The process is stopped at the time read_regs is called.
 105  *
 106  * proc_write_regs(proc, regs)
 107  *      Update the current register set from the passed in regs
 108  *      structure.  Take care to avoid clobbering special CPU
 109  *      registers or privileged bits in the PSL.
 110  *      Depending on the architecture this may have fix-up work to do,
 111  *      especially if the IAR or PCW are modified.
 112  *      The process is stopped at the time write_regs is called.
 113  *
 114  * proc_read_fpregs, proc_write_fpregs
 115  *      deal with the floating point register set, otherwise as above.
 116  *
 117  * proc_read_dbregs, proc_write_dbregs
 118  *      deal with the processor debug register set, otherwise as above.
 119  *
 120  * proc_sstep(proc)
 121  *      Arrange for the process to trap after executing a single instruction.
 122  */
 123
 124 #define PROC_ACTION(action) do {                                        \
 125         int error;                                                      \
 126                                                                         \
 127         PROC_LOCK_ASSERT(td->td_proc, MA_OWNED);                        \
 128         if ((td->td_proc->p_flag & P_INMEM) == 0)                       \
 129                 error = EIO;                                            \
 130         else                                                            \
 131                 error = (action);                                       \
 132         return (error);                                                 \
 133 } while(0)
 134
 135 int
 136 proc_read_regs(struct thread *td, struct reg *regs)
 137 {
 138
 139         PROC_ACTION(fill_regs(td, regs));
 140 }
 141
 142 int
 143 proc_write_regs(struct thread *td, struct reg *regs)
 144 {
 145
 146         PROC_ACTION(set_regs(td, regs));
 147 }
 148
 149 int
 150 proc_read_dbregs(struct thread *td, struct dbreg *dbregs)
 151 {
 152
 153         PROC_ACTION(fill_dbregs(td, dbregs));
 154 }
 155
 156 int
 157 proc_write_dbregs(struct thread *td, struct dbreg *dbregs)
 158 {
 159
 160         PROC_ACTION(set_dbregs(td, dbregs));
 161 }
 162
 163 /*
 164  * Ptrace doesn't support fpregs at all, and there are no security holes
 165  * or translations for fpregs, so we can just copy them.
 166  */
 167 int
 168 proc_read_fpregs(struct thread *td, struct fpreg *fpregs)
 169 {
 170
 171         PROC_ACTION(fill_fpregs(td, fpregs));
 172 }
 173
 174 int
 175 proc_write_fpregs(struct thread *td, struct fpreg *fpregs)
 176 {
 177
 178         PROC_ACTION(set_fpregs(td, fpregs));
 179 }
 180
 181 #ifdef COMPAT_FREEBSD32
 182 /* For 32 bit binaries, we need to expose the 32 bit regs layouts. */
 183 int
 184 proc_read_regs32(struct thread *td, struct reg32 *regs32)
 185 {
 186
 187         PROC_ACTION(fill_regs32(td, regs32));
 188 }
 189
 190 int
 191 proc_write_regs32(struct thread *td, struct reg32 *regs32)
 192 {
 193
 194         PROC_ACTION(set_regs32(td, regs32));
 195 }
 196
 197 int
 198 proc_read_dbregs32(struct thread *td, struct dbreg32 *dbregs32)
 199 {
 200
 201         PROC_ACTION(fill_dbregs32(td, dbregs32));
 202 }
 203
 204 int
 205 proc_write_dbregs32(struct thread *td, struct dbreg32 *dbregs32)
 206 {
 207
 208         PROC_ACTION(set_dbregs32(td, dbregs32));
 209 }
 210
 211 int
 212 proc_read_fpregs32(struct thread *td, struct fpreg32 *fpregs32)
 213 {
 214
 215         PROC_ACTION(fill_fpregs32(td, fpregs32));
 216 }
 217
 218 int
 219 proc_write_fpregs32(struct thread *td, struct fpreg32 *fpregs32)
 220 {
 221
 222         PROC_ACTION(set_fpregs32(td, fpregs32));
 223 }
 224 #endif
 225
 226 int
 227 proc_sstep(struct thread *td)
 228 {
 229
 230         PROC_ACTION(ptrace_single_step(td));
 231 }
 232
 233 int
 234 proc_rwmem(struct proc *p, struct uio *uio)
 235 {
 236         vm_map_t map;
 237         vm_offset_t pageno;             /* page number */
 238         vm_prot_t reqprot;
 239         int error, fault_flags, page_offset, writing;
 240
 241         /*
 242          * Assert that someone has locked this vmspace.  (Should be
 243          * curthread but we can't assert that.)  This keeps the process
 244          * from exiting out from under us until this operation completes.
 245          */
 246         PROC_ASSERT_HELD(p);
 247         PROC_LOCK_ASSERT(p, MA_NOTOWNED);
 248
 249         /*
 250          * The map we want...
 251          */
 252         map = &p->p_vmspace->vm_map;
 253
 254         /*
 255          * If we are writing, then we request vm_fault() to create a private
 256          * copy of each page.  Since these copies will not be writeable by the
 257          * process, we must explicity request that they be dirtied.
 258          */
 259         writing = uio->uio_rw == UIO_WRITE;
 260         reqprot = writing ? VM_PROT_COPY | VM_PROT_READ : VM_PROT_READ;
 261         fault_flags = writing ? VM_FAULT_DIRTY : VM_FAULT_NORMAL;
 262
 263         /*
 264          * Only map in one page at a time.  We don't have to, but it
 265          * makes things easier.  This way is trivial - right?
 266          */
 267         do {
 268                 vm_offset_t uva;
 269                 u_int len;
 270                 vm_page_t m;
 271
 272                 uva = (vm_offset_t)uio->uio_offset;
 273
 274                 /*
 275                  * Get the page number of this segment.
 276                  */
 277                 pageno = trunc_page(uva);
 278                 page_offset = uva - pageno;
 279
 280                 /*
 281                  * How many bytes to copy
 282                  */
 283                 len = min(PAGE_SIZE - page_offset, uio->uio_resid);
 284
 285                 /*
 286                  * Fault and hold the page on behalf of the process.
 287                  */
 288                 error = vm_fault_hold(map, pageno, reqprot, fault_flags, &m);
 289                 if (error != KERN_SUCCESS) {
 290                         if (error == KERN_RESOURCE_SHORTAGE)
 291                                 error = ENOMEM;
 292                         else
 293                                 error = EFAULT;
 294                         break;
 295                 }
 296
 297                 /*
 298                  * Now do the i/o move.
 299                  */
 300                 error = uiomove_fromphys(&m, page_offset, len, uio);
 301
 302                 /* Make the I-cache coherent for breakpoints. */
 303                 if (writing && error == 0) {
 304                         vm_map_lock_read(map);
 305                         if (vm_map_check_protection(map, pageno, pageno +
 306                             PAGE_SIZE, VM_PROT_EXECUTE))
 307                                 vm_sync_icache(map, uva, len);
 308                         vm_map_unlock_read(map);
 309                 }
 310
 311                 /*
 312                  * Release the page.
 313                  */
 314                 vm_page_lock(m);
 315                 if (vm_page_unwire(m, PQ_ACTIVE) && m->object == NULL)
 316                         vm_page_free(m);
 317                 vm_page_unlock(m);
 318
 319         } while (error == 0 && uio->uio_resid > 0);
 320
 321         return (error);
 322 }
 323
 324 static ssize_t
 325 proc_iop(struct thread *td, struct proc *p, vm_offset_t va, void *buf,
 326     size_t len, enum uio_rw rw)
 327 {
 328         struct iovec iov;
 329         struct uio uio;
 330         ssize_t slen;
 331
 332         MPASS(len < SSIZE_MAX);
 333         slen = (ssize_t)len;
 334
 335         iov.iov_base = (caddr_t)buf;
 336         iov.iov_len = len;
 337         uio.uio_iov = &iov;
 338         uio.uio_iovcnt = 1;
 339         uio.uio_offset = va;
 340         uio.uio_resid = slen;
 341         uio.uio_segflg = UIO_SYSSPACE;
 342         uio.uio_rw = rw;
 343         uio.uio_td = td;
 344         proc_rwmem(p, &uio);
 345         if (uio.uio_resid == slen)
 346                 return (-1);
 347         return (slen - uio.uio_resid);
 348 }
 349
 350 ssize_t
 351 proc_readmem(struct thread *td, struct proc *p, vm_offset_t va, void *buf,
 352     size_t len)
 353 {
 354
 355         return (proc_iop(td, p, va, buf, len, UIO_READ));
 356 }
 357
 358 ssize_t
 359 proc_writemem(struct thread *td, struct proc *p, vm_offset_t va, void *buf,
 360     size_t len)
 361 {
 362
 363         return (proc_iop(td, p, va, buf, len, UIO_WRITE));
 364 }
 365
 366 static int
 367 ptrace_vm_entry(struct thread *td, struct proc *p, struct ptrace_vm_entry *pve)
 368 {
 369         struct vattr vattr;
 370         vm_map_t map;
 371         vm_map_entry_t entry;
 372         vm_object_t obj, tobj, lobj;
 373         struct vmspace *vm;
 374         struct vnode *vp;
 375         char *freepath, *fullpath;
 376         u_int pathlen;
 377         int error, index;
 378
 379         error = 0;
 380         obj = NULL;
 381
 382         vm = vmspace_acquire_ref(p);
 383         map = &vm->vm_map;
 384         vm_map_lock_read(map);
 385
 386         do {
 387                 entry = map->header.next;
 388                 index = 0;
 389                 while (index < pve->pve_entry && entry != &map->header) {
 390                         entry = entry->next;
 391                         index++;
 392                 }
 393                 if (index != pve->pve_entry) {
 394                         error = EINVAL;
 395                         break;
 396                 }
 397                 KASSERT((map->header.eflags & MAP_ENTRY_IS_SUB_MAP) == 0,
 398                     ("Submap in map header"));
 399                 while ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) != 0) {
 400                         entry = entry->next;
 401                         index++;
 402                 }
 403                 if (entry == &map->header) {
 404                         error = ENOENT;
 405                         break;
 406                 }
 407
 408                 /* We got an entry. */
 409                 pve->pve_entry = index + 1;
 410                 pve->pve_timestamp = map->timestamp;
 411                 pve->pve_start = entry->start;
 412                 pve->pve_end = entry->end - 1;
 413                 pve->pve_offset = entry->offset;
 414                 pve->pve_prot = entry->protection;
 415
 416                 /* Backing object's path needed? */
 417                 if (pve->pve_pathlen == 0)
 418                         break;
 419
 420                 pathlen = pve->pve_pathlen;
 421                 pve->pve_pathlen = 0;
 422
 423                 obj = entry->object.vm_object;
 424                 if (obj != NULL)
 425                         VM_OBJECT_RLOCK(obj);
 426         } while (0);
 427
 428         vm_map_unlock_read(map);
 429
 430         pve->pve_fsid = VNOVAL;
 431         pve->pve_fileid = VNOVAL;
 432
 433         if (error == 0 && obj != NULL) {
 434                 lobj = obj;
 435                 for (tobj = obj; tobj != NULL; tobj = tobj->backing_object) {
 436                         if (tobj != obj)
 437                                 VM_OBJECT_RLOCK(tobj);
 438                         if (lobj != obj)
 439                                 VM_OBJECT_RUNLOCK(lobj);
 440                         lobj = tobj;
 441                         pve->pve_offset += tobj->backing_object_offset;
 442                 }
 443                 vp = vm_object_vnode(lobj);
 444                 if (vp != NULL)
 445                         vref(vp);
 446                 if (lobj != obj)
 447                         VM_OBJECT_RUNLOCK(lobj);
 448                 VM_OBJECT_RUNLOCK(obj);
 449
 450                 if (vp != NULL) {
 451                         freepath = NULL;
 452                         fullpath = NULL;
 453                         vn_fullpath(td, vp, &fullpath, &freepath);
 454                         vn_lock(vp, LK_SHARED | LK_RETRY);
 455                         if (VOP_GETATTR(vp, &vattr, td->td_ucred) == 0) {
 456                                 pve->pve_fileid = vattr.va_fileid;
 457                                 pve->pve_fsid = vattr.va_fsid;
 458                         }
 459                         vput(vp);
 460
 461                         if (fullpath != NULL) {
 462                                 pve->pve_pathlen = strlen(fullpath) + 1;
 463                                 if (pve->pve_pathlen <= pathlen) {
 464                                         error = copyout(fullpath, pve->pve_path,
 465                                             pve->pve_pathlen);
 466                                 } else
 467                                         error = ENAMETOOLONG;
 468                         }
 469                         if (freepath != NULL)
 470                                 free(freepath, M_TEMP);
 471                 }
 472         }
 473         vmspace_free(vm);
 474         if (error == 0)
 475                 CTR3(KTR_PTRACE, "PT_VM_ENTRY: pid %d, entry %d, start %p",
 476                     p->p_pid, pve->pve_entry, pve->pve_start);
 477
 478         return (error);
 479 }
 480
 481 #ifdef COMPAT_FREEBSD32
 482 static int
 483 ptrace_vm_entry32(struct thread *td, struct proc *p,
 484     struct ptrace_vm_entry32 *pve32)
 485 {
 486         struct ptrace_vm_entry pve;
 487         int error;
 488
 489         pve.pve_entry = pve32->pve_entry;
 490         pve.pve_pathlen = pve32->pve_pathlen;
 491         pve.pve_path = (void *)(uintptr_t)pve32->pve_path;
 492
 493         error = ptrace_vm_entry(td, p, &pve);
 494         if (error == 0) {
 495                 pve32->pve_entry = pve.pve_entry;
 496                 pve32->pve_timestamp = pve.pve_timestamp;
 497                 pve32->pve_start = pve.pve_start;
 498                 pve32->pve_end = pve.pve_end;
 499                 pve32->pve_offset = pve.pve_offset;
 500                 pve32->pve_prot = pve.pve_prot;
 501                 pve32->pve_fileid = pve.pve_fileid;
 502                 pve32->pve_fsid = pve.pve_fsid;
 503         }
 504
 505         pve32->pve_pathlen = pve.pve_pathlen;
 506         return (error);
 507 }
 508
 509 static void
 510 ptrace_lwpinfo_to32(const struct ptrace_lwpinfo *pl,
 511     struct ptrace_lwpinfo32 *pl32)
 512 {
 513
 514         bzero(pl32, sizeof(*pl32));
 515         pl32->pl_lwpid = pl->pl_lwpid;
 516         pl32->pl_event = pl->pl_event;
 517         pl32->pl_flags = pl->pl_flags;
 518         pl32->pl_sigmask = pl->pl_sigmask;
 519         pl32->pl_siglist = pl->pl_siglist;
 520         siginfo_to_siginfo32(&pl->pl_siginfo, &pl32->pl_siginfo);
 521         strcpy(pl32->pl_tdname, pl->pl_tdname);
 522         pl32->pl_child_pid = pl->pl_child_pid;
 523         pl32->pl_syscall_code = pl->pl_syscall_code;
 524         pl32->pl_syscall_narg = pl->pl_syscall_narg;
 525 }
 526
 527 static void
 528 ptrace_sc_ret_to32(const struct ptrace_sc_ret *psr,
 529     struct ptrace_sc_ret32 *psr32)
 530 {
 531
 532         bzero(psr32, sizeof(*psr32));
 533         psr32->sr_retval[0] = psr->sr_retval[0];
 534         psr32->sr_retval[1] = psr->sr_retval[1];
 535         psr32->sr_error = psr->sr_error;
 536 }
 537 #endif /* COMPAT_FREEBSD32 */
 538
 539 /*
 540  * Process debugging system call.
 541  */
 542 #ifndef _SYS_SYSPROTO_H_
 543 struct ptrace_args {
 544         int     req;
 545         pid_t   pid;
 546         caddr_t addr;
 547         int     data;
 548 };
 549 #endif
 550
 551 #ifdef COMPAT_FREEBSD32
 552 /*
 553  * This CPP subterfuge is to try and reduce the number of ifdefs in
 554  * the body of the code.
 555  *   COPYIN(uap->addr, &r.reg, sizeof r.reg);
 556  * becomes either:
 557  *   copyin(uap->addr, &r.reg, sizeof r.reg);
 558  * or
 559  *   copyin(uap->addr, &r.reg32, sizeof r.reg32);
 560  * .. except this is done at runtime.
 561  */
 562 #define BZERO(a, s)             wrap32 ? \
 563         bzero(a ## 32, s ## 32) : \
 564         bzero(a, s)
 565 #define COPYIN(u, k, s)         wrap32 ? \
 566         copyin(u, k ## 32, s ## 32) : \
 567         copyin(u, k, s)
 568 #define COPYOUT(k, u, s)        wrap32 ? \
 569         copyout(k ## 32, u, s ## 32) : \
 570         copyout(k, u, s)
 571 #else
 572 #define BZERO(a, s)             bzero(a, s)
 573 #define COPYIN(u, k, s)         copyin(u, k, s)
 574 #define COPYOUT(k, u, s)        copyout(k, u, s)
 575 #endif
 576 int
 577 sys_ptrace(struct thread *td, struct ptrace_args *uap)
 578 {
 579         /*
 580          * XXX this obfuscation is to reduce stack usage, but the register
 581          * structs may be too large to put on the stack anyway.
 582          */
 583         union {
 584                 struct ptrace_io_desc piod;
 585                 struct ptrace_lwpinfo pl;
 586                 struct ptrace_vm_entry pve;
 587                 struct dbreg dbreg;
 588                 struct fpreg fpreg;
 589                 struct reg reg;
 590 #ifdef COMPAT_FREEBSD32
 591                 struct dbreg32 dbreg32;
 592                 struct fpreg32 fpreg32;
 593                 struct reg32 reg32;
 594                 struct ptrace_io_desc32 piod32;
 595                 struct ptrace_lwpinfo32 pl32;
 596                 struct ptrace_vm_entry32 pve32;
 597 #endif
 598                 char args[sizeof(td->td_sa.args)];
 599                 struct ptrace_sc_ret psr;
 600                 int ptevents;
 601         } r;
 602         void *addr;
 603         int error = 0;
 604 #ifdef COMPAT_FREEBSD32
 605         int wrap32 = 0;
 606
 607         if (SV_CURPROC_FLAG(SV_ILP32))
 608                 wrap32 = 1;
 609 #endif
 610         AUDIT_ARG_PID(uap->pid);
 611         AUDIT_ARG_CMD(uap->req);
 612         AUDIT_ARG_VALUE(uap->data);
 613         addr = &r;
 614         switch (uap->req) {
 615         case PT_GET_EVENT_MASK:
 616         case PT_LWPINFO:
 617         case PT_GET_SC_ARGS:
 618         case PT_GET_SC_RET:
 619                 break;
 620         case PT_GETREGS:
 621                 BZERO(&r.reg, sizeof r.reg);
 622                 break;
 623         case PT_GETFPREGS:
 624                 BZERO(&r.fpreg, sizeof r.fpreg);
 625                 break;
 626         case PT_GETDBREGS:
 627                 BZERO(&r.dbreg, sizeof r.dbreg);
 628                 break;
 629         case PT_SETREGS:
 630                 error = COPYIN(uap->addr, &r.reg, sizeof r.reg);
 631                 break;
 632         case PT_SETFPREGS:
 633                 error = COPYIN(uap->addr, &r.fpreg, sizeof r.fpreg);
 634                 break;
 635         case PT_SETDBREGS:
 636                 error = COPYIN(uap->addr, &r.dbreg, sizeof r.dbreg);
 637                 break;
 638         case PT_SET_EVENT_MASK:
 639                 if (uap->data != sizeof(r.ptevents))
 640                         error = EINVAL;
 641                 else
 642                         error = copyin(uap->addr, &r.ptevents, uap->data);
 643                 break;
 644         case PT_IO:
 645                 error = COPYIN(uap->addr, &r.piod, sizeof r.piod);
 646                 break;
 647         case PT_VM_ENTRY:
 648                 error = COPYIN(uap->addr, &r.pve, sizeof r.pve);
 649                 break;
 650         default:
 651                 addr = uap->addr;
 652                 break;
 653         }
 654         if (error)
 655                 return (error);
 656
 657         error = kern_ptrace(td, uap->req, uap->pid, addr, uap->data);
 658         if (error)
 659                 return (error);
 660
 661         switch (uap->req) {
 662         case PT_VM_ENTRY:
 663                 error = COPYOUT(&r.pve, uap->addr, sizeof r.pve);
 664                 break;
 665         case PT_IO:
 666                 error = COPYOUT(&r.piod, uap->addr, sizeof r.piod);
 667                 break;
 668         case PT_GETREGS:
 669                 error = COPYOUT(&r.reg, uap->addr, sizeof r.reg);
 670                 break;
 671         case PT_GETFPREGS:
 672                 error = COPYOUT(&r.fpreg, uap->addr, sizeof r.fpreg);
 673                 break;
 674         case PT_GETDBREGS:
 675                 error = COPYOUT(&r.dbreg, uap->addr, sizeof r.dbreg);
 676                 break;
 677         case PT_GET_EVENT_MASK:
 678                 /* NB: The size in uap->data is validated in kern_ptrace(). */
 679                 error = copyout(&r.ptevents, uap->addr, uap->data);
 680                 break;
 681         case PT_LWPINFO:
 682                 /* NB: The size in uap->data is validated in kern_ptrace(). */
 683                 error = copyout(&r.pl, uap->addr, uap->data);
 684                 break;
 685         case PT_GET_SC_ARGS:
 686                 error = copyout(r.args, uap->addr, MIN(uap->data,
 687                     sizeof(r.args)));
 688                 break;
 689         case PT_GET_SC_RET:
 690                 error = copyout(&r.psr, uap->addr, MIN(uap->data,
 691                     sizeof(r.psr)));
 692                 break;
 693         }
 694
 695         return (error);
 696 }
 697 #undef COPYIN
 698 #undef COPYOUT
 699 #undef BZERO
 700
 701 #ifdef COMPAT_FREEBSD32
 702 /*
 703  *   PROC_READ(regs, td2, addr);
 704  * becomes either:
 705  *   proc_read_regs(td2, addr);
 706  * or
 707  *   proc_read_regs32(td2, addr);
 708  * .. except this is done at runtime.  There is an additional
 709  * complication in that PROC_WRITE disallows 32 bit consumers
 710  * from writing to 64 bit address space targets.
 711  */
 712 #define PROC_READ(w, t, a)      wrap32 ? \
 713         proc_read_ ## w ## 32(t, a) : \
 714         proc_read_ ## w (t, a)
 715 #define PROC_WRITE(w, t, a)     wrap32 ? \
 716         (safe ? proc_write_ ## w ## 32(t, a) : EINVAL ) : \
 717         proc_write_ ## w (t, a)
 718 #else
 719 #define PROC_READ(w, t, a)      proc_read_ ## w (t, a)
 720 #define PROC_WRITE(w, t, a)     proc_write_ ## w (t, a)
 721 #endif
 722
 723 void
 724 proc_set_traced(struct proc *p, bool stop)
 725 {
 726
 727         sx_assert(&proctree_lock, SX_XLOCKED);
 728         PROC_LOCK_ASSERT(p, MA_OWNED);
 729         p->p_flag |= P_TRACED;
 730         if (stop)
 731                 p->p_flag2 |= P2_PTRACE_FSTP;
 732         p->p_ptevents = PTRACE_DEFAULT;
 733 }
 734
 735 int
 736 kern_ptrace(struct thread *td, int req, pid_t pid, void *addr, int data)
 737 {
 738         struct iovec iov;
 739         struct uio uio;
 740         struct proc *curp, *p, *pp;
 741         struct thread *td2 = NULL, *td3;
 742         struct ptrace_io_desc *piod = NULL;
 743         struct ptrace_lwpinfo *pl;
 744         struct ptrace_sc_ret *psr;
 745         int error, num, tmp;
 746         int proctree_locked = 0;
 747         lwpid_t tid = 0, *buf;
 748 #ifdef COMPAT_FREEBSD32
 749         int wrap32 = 0, safe = 0;
 750         struct ptrace_io_desc32 *piod32 = NULL;
 751         struct ptrace_lwpinfo32 *pl32 = NULL;
 752         struct ptrace_sc_ret32 *psr32 = NULL;
 753         union {
 754                 struct ptrace_lwpinfo pl;
 755                 struct ptrace_sc_ret psr;
 756         } r;
 757 #endif
 758
 759         curp = td->td_proc;
 760
 761         /* Lock proctree before locking the process. */
 762         switch (req) {
 763         case PT_TRACE_ME:
 764         case PT_ATTACH:
 765         case PT_STEP:
 766         case PT_CONTINUE:
 767         case PT_TO_SCE:
 768         case PT_TO_SCX:
 769         case PT_SYSCALL:
 770         case PT_FOLLOW_FORK:
 771         case PT_LWP_EVENTS:
 772         case PT_GET_EVENT_MASK:
 773         case PT_SET_EVENT_MASK:
 774         case PT_DETACH:
 775         case PT_GET_SC_ARGS:
 776                 sx_xlock(&proctree_lock);
 777                 proctree_locked = 1;
 778                 break;
 779         default:
 780                 break;
 781         }
 782
 783         if (req == PT_TRACE_ME) {
 784                 p = td->td_proc;
 785                 PROC_LOCK(p);
 786         } else {
 787                 if (pid <= PID_MAX) {
 788                         if ((p = pfind(pid)) == NULL) {
 789                                 if (proctree_locked)
 790                                         sx_xunlock(&proctree_lock);
 791                                 return (ESRCH);
 792                         }
 793                 } else {
 794                         td2 = tdfind(pid, -1);
 795                         if (td2 == NULL) {
 796                                 if (proctree_locked)
 797                                         sx_xunlock(&proctree_lock);
 798                                 return (ESRCH);
 799                         }
 800                         p = td2->td_proc;
 801                         tid = pid;
 802                         pid = p->p_pid;
 803                 }
 804         }
 805         AUDIT_ARG_PROCESS(p);
 806
 807         if ((p->p_flag & P_WEXIT) != 0) {
 808                 error = ESRCH;
 809                 goto fail;
 810         }
 811         if ((error = p_cansee(td, p)) != 0)
 812                 goto fail;
 813
 814         if ((error = p_candebug(td, p)) != 0)
 815                 goto fail;
 816
 817         /*
 818          * System processes can't be debugged.
 819          */
 820         if ((p->p_flag & P_SYSTEM) != 0) {
 821                 error = EINVAL;
 822                 goto fail;
 823         }
 824
 825         if (tid == 0) {
 826                 if ((p->p_flag & P_STOPPED_TRACE) != 0) {
 827                         KASSERT(p->p_xthread != NULL, ("NULL p_xthread"));
 828                         td2 = p->p_xthread;
 829                 } else {
 830                         td2 = FIRST_THREAD_IN_PROC(p);
 831                 }
 832                 tid = td2->td_tid;
 833         }
 834
 835 #ifdef COMPAT_FREEBSD32
 836         /*
 837          * Test if we're a 32 bit client and what the target is.
 838          * Set the wrap controls accordingly.
 839          */
 840         if (SV_CURPROC_FLAG(SV_ILP32)) {
 841                 if (SV_PROC_FLAG(td2->td_proc, SV_ILP32))
 842                         safe = 1;
 843                 wrap32 = 1;
 844         }
 845 #endif
 846         /*
 847          * Permissions check
 848          */
 849         switch (req) {
 850         case PT_TRACE_ME:
 851                 /*
 852                  * Always legal, when there is a parent process which
 853                  * could trace us.  Otherwise, reject.
 854                  */
 855                 if ((p->p_flag & P_TRACED) != 0) {
 856                         error = EBUSY;
 857                         goto fail;
 858                 }
 859                 if (p->p_pptr == initproc) {
 860                         error = EPERM;
 861                         goto fail;
 862                 }
 863                 break;
 864
 865         case PT_ATTACH:
 866                 /* Self */
 867                 if (p == td->td_proc) {
 868                         error = EINVAL;
 869                         goto fail;
 870                 }
 871
 872                 /* Already traced */
 873                 if (p->p_flag & P_TRACED) {
 874                         error = EBUSY;
 875                         goto fail;
 876                 }
 877
 878                 /* Can't trace an ancestor if you're being traced. */
 879                 if (curp->p_flag & P_TRACED) {
 880                         for (pp = curp->p_pptr; pp != NULL; pp = pp->p_pptr) {
 881                                 if (pp == p) {
 882                                         error = EINVAL;
 883                                         goto fail;
 884                                 }
 885                         }
 886                 }
 887
 888
 889                 /* OK */
 890                 break;
 891
 892         case PT_CLEARSTEP:
 893                 /* Allow thread to clear single step for itself */
 894                 if (td->td_tid == tid)
 895                         break;
 896
 897                 /* FALLTHROUGH */
 898         default:
 899                 /* not being traced... */
 900                 if ((p->p_flag & P_TRACED) == 0) {
 901                         error = EPERM;
 902                         goto fail;
 903                 }
 904
 905                 /* not being traced by YOU */
 906                 if (p->p_pptr != td->td_proc) {
 907                         error = EBUSY;
 908                         goto fail;
 909                 }
 910
 911                 /* not currently stopped */
 912                 if ((p->p_flag & P_STOPPED_TRACE) == 0 ||
 913                     p->p_suspcount != p->p_numthreads  ||
 914                     (p->p_flag & P_WAITED) == 0) {
 915                         error = EBUSY;
 916                         goto fail;
 917                 }
 918
 919                 /* OK */
 920                 break;
 921         }
 922
 923         /* Keep this process around until we finish this request. */
 924         _PHOLD(p);
 925
 926 #ifdef FIX_SSTEP
 927         /*
 928          * Single step fixup ala procfs
 929          */
 930         FIX_SSTEP(td2);
 931 #endif
 932
 933         /*
 934          * Actually do the requests
 935          */
 936
 937         td->td_retval[0] = 0;
 938
 939         switch (req) {
 940         case PT_TRACE_ME:
 941                 /* set my trace flag and "owner" so it can read/write me */
 942                 proc_set_traced(p, false);
 943                 if (p->p_flag & P_PPWAIT)
 944                         p->p_flag |= P_PPTRACE;
 945                 CTR1(KTR_PTRACE, "PT_TRACE_ME: pid %d", p->p_pid);
 946                 break;
 947
 948         case PT_ATTACH:
 949                 /* security check done above */
 950                 /*
 951                  * It would be nice if the tracing relationship was separate
 952                  * from the parent relationship but that would require
 953                  * another set of links in the proc struct or for "wait"
 954                  * to scan the entire proc table.  To make life easier,
 955                  * we just re-parent the process we're trying to trace.
 956                  * The old parent is remembered so we can put things back
 957                  * on a "detach".
 958                  */
 959                 proc_set_traced(p, true);
 960                 if (p->p_pptr != td->td_proc) {
 961                         proc_reparent(p, td->td_proc, false);
 962                 }
 963                 CTR2(KTR_PTRACE, "PT_ATTACH: pid %d, oppid %d", p->p_pid,
 964                     p->p_oppid);
 965
 966                 sx_xunlock(&proctree_lock);
 967                 proctree_locked = 0;
 968                 MPASS(p->p_xthread == NULL);
 969                 MPASS((p->p_flag & P_STOPPED_TRACE) == 0);
 970
 971                 /*
 972                  * If already stopped due to a stop signal, clear the
 973                  * existing stop before triggering a traced SIGSTOP.
 974                  */
 975                 if ((p->p_flag & P_STOPPED_SIG) != 0) {
 976                         PROC_SLOCK(p);
 977                         p->p_flag &= ~(P_STOPPED_SIG | P_WAITED);
 978                         thread_unsuspend(p);
 979                         PROC_SUNLOCK(p);
 980                 }
 981
 982                 kern_psignal(p, SIGSTOP);
 983                 break;
 984
 985         case PT_CLEARSTEP:
 986                 CTR2(KTR_PTRACE, "PT_CLEARSTEP: tid %d (pid %d)", td2->td_tid,
 987                     p->p_pid);
 988                 error = ptrace_clear_single_step(td2);
 989                 break;
 990
 991         case PT_SETSTEP:
 992                 CTR2(KTR_PTRACE, "PT_SETSTEP: tid %d (pid %d)", td2->td_tid,
 993                     p->p_pid);
 994                 error = ptrace_single_step(td2);
 995                 break;
 996
 997         case PT_SUSPEND:
 998                 CTR2(KTR_PTRACE, "PT_SUSPEND: tid %d (pid %d)", td2->td_tid,
 999                     p->p_pid);
1000                 td2->td_dbgflags |= TDB_SUSPEND;
1001                 thread_lock(td2);
1002                 td2->td_flags |= TDF_NEEDSUSPCHK;
1003                 thread_unlock(td2);
1004                 break;
1005
1006         case PT_RESUME:
1007                 CTR2(KTR_PTRACE, "PT_RESUME: tid %d (pid %d)", td2->td_tid,
1008                     p->p_pid);
1009                 td2->td_dbgflags &= ~TDB_SUSPEND;
1010                 break;
1011
1012         case PT_FOLLOW_FORK:
1013                 CTR3(KTR_PTRACE, "PT_FOLLOW_FORK: pid %d %s -> %s", p->p_pid,
1014                     p->p_ptevents & PTRACE_FORK ? "enabled" : "disabled",
1015                     data ? "enabled" : "disabled");
1016                 if (data)
1017                         p->p_ptevents |= PTRACE_FORK;
1018                 else
1019                         p->p_ptevents &= ~PTRACE_FORK;
1020                 break;
1021
1022         case PT_LWP_EVENTS:
1023                 CTR3(KTR_PTRACE, "PT_LWP_EVENTS: pid %d %s -> %s", p->p_pid,
1024                     p->p_ptevents & PTRACE_LWP ? "enabled" : "disabled",
1025                     data ? "enabled" : "disabled");
1026                 if (data)
1027                         p->p_ptevents |= PTRACE_LWP;
1028                 else
1029                         p->p_ptevents &= ~PTRACE_LWP;
1030                 break;
1031
1032         case PT_GET_EVENT_MASK:
1033                 if (data != sizeof(p->p_ptevents)) {
1034                         error = EINVAL;
1035                         break;
1036                 }
1037                 CTR2(KTR_PTRACE, "PT_GET_EVENT_MASK: pid %d mask %#x", p->p_pid,
1038                     p->p_ptevents);
1039                 *(int *)addr = p->p_ptevents;
1040                 break;
1041
1042         case PT_SET_EVENT_MASK:
1043                 if (data != sizeof(p->p_ptevents)) {
1044                         error = EINVAL;
1045                         break;
1046                 }
1047                 tmp = *(int *)addr;
1048                 if ((tmp & ~(PTRACE_EXEC | PTRACE_SCE | PTRACE_SCX |
1049                     PTRACE_FORK | PTRACE_LWP | PTRACE_VFORK)) != 0) {
1050                         error = EINVAL;
1051                         break;
1052                 }
1053                 CTR3(KTR_PTRACE, "PT_SET_EVENT_MASK: pid %d mask %#x -> %#x",
1054                     p->p_pid, p->p_ptevents, tmp);
1055                 p->p_ptevents = tmp;
1056                 break;
1057
1058         case PT_GET_SC_ARGS:
1059                 CTR1(KTR_PTRACE, "PT_GET_SC_ARGS: pid %d", p->p_pid);
1060                 if ((td2->td_dbgflags & (TDB_SCE | TDB_SCX)) == 0
1061 #ifdef COMPAT_FREEBSD32
1062                     || (wrap32 && !safe)
1063 #endif
1064                     ) {
1065                         error = EINVAL;
1066                         break;
1067                 }
1068                 bzero(addr, sizeof(td2->td_sa.args));
1069 #ifdef COMPAT_FREEBSD32
1070                 if (wrap32)
1071                         for (num = 0; num < nitems(td2->td_sa.args); num++)
1072                                 ((uint32_t *)addr)[num] = (uint32_t)
1073                                     td2->td_sa.args[num];
1074                 else
1075 #endif
1076                         bcopy(td2->td_sa.args, addr, td2->td_sa.narg *
1077                             sizeof(register_t));
1078                 break;
1079
1080         case PT_GET_SC_RET:
1081                 if ((td2->td_dbgflags & (TDB_SCX)) == 0
1082 #ifdef COMPAT_FREEBSD32
1083                     || (wrap32 && !safe)
1084 #endif
1085                     ) {
1086                         error = EINVAL;
1087                         break;
1088                 }
1089 #ifdef COMPAT_FREEBSD32
1090                 if (wrap32) {
1091                         psr = &r.psr;
1092                         psr32 = addr;
1093                 } else
1094 #endif
1095                 psr = addr;
1096                 bzero(psr, sizeof(*psr));
1097                 psr->sr_error = td2->td_errno;
1098                 if (psr->sr_error == 0) {
1099                         psr->sr_retval[0] = td2->td_retval[0];
1100                         psr->sr_retval[1] = td2->td_retval[1];
1101                 }
1102 #ifdef COMPAT_FREEBSD32
1103                 if (wrap32)
1104                         ptrace_sc_ret_to32(psr, psr32);
1105 #endif
1106                 CTR4(KTR_PTRACE,
1107                     "PT_GET_SC_RET: pid %d error %d retval %#lx,%#lx",
1108                     p->p_pid, psr->sr_error, psr->sr_retval[0],
1109                     psr->sr_retval[1]);
1110                 break;
1111
1112         case PT_STEP:
1113         case PT_CONTINUE:
1114         case PT_TO_SCE:
1115         case PT_TO_SCX:
1116         case PT_SYSCALL:
1117         case PT_DETACH:
1118                 /* Zero means do not send any signal */
1119                 if (data < 0 || data > _SIG_MAXSIG) {
1120                         error = EINVAL;
1121                         break;
1122                 }
1123
1124                 switch (req) {
1125                 case PT_STEP:
1126                         CTR3(KTR_PTRACE, "PT_STEP: tid %d (pid %d), sig = %d",
1127                             td2->td_tid, p->p_pid, data);
1128                         error = ptrace_single_step(td2);
1129                         if (error)
1130                                 goto out;
1131                         break;
1132                 case PT_CONTINUE:
1133                 case PT_TO_SCE:
1134                 case PT_TO_SCX:
1135                 case PT_SYSCALL:
1136                         if (addr != (void *)1) {
1137                                 error = ptrace_set_pc(td2,
1138                                     (u_long)(uintfptr_t)addr);
1139                                 if (error)
1140                                         goto out;
1141                         }
1142                         switch (req) {
1143                         case PT_TO_SCE:
1144                                 p->p_ptevents |= PTRACE_SCE;
1145                                 CTR4(KTR_PTRACE,
1146                     "PT_TO_SCE: pid %d, events = %#x, PC = %#lx, sig = %d",
1147                                     p->p_pid, p->p_ptevents,
1148                                     (u_long)(uintfptr_t)addr, data);
1149                                 break;
1150                         case PT_TO_SCX:
1151                                 p->p_ptevents |= PTRACE_SCX;
1152                                 CTR4(KTR_PTRACE,
1153                     "PT_TO_SCX: pid %d, events = %#x, PC = %#lx, sig = %d",
1154                                     p->p_pid, p->p_ptevents,
1155                                     (u_long)(uintfptr_t)addr, data);
1156                                 break;
1157                         case PT_SYSCALL:
1158                                 p->p_ptevents |= PTRACE_SYSCALL;
1159                                 CTR4(KTR_PTRACE,
1160                     "PT_SYSCALL: pid %d, events = %#x, PC = %#lx, sig = %d",
1161                                     p->p_pid, p->p_ptevents,
1162                                     (u_long)(uintfptr_t)addr, data);
1163                                 break;
1164                         case PT_CONTINUE:
1165                                 CTR3(KTR_PTRACE,
1166                                     "PT_CONTINUE: pid %d, PC = %#lx, sig = %d",
1167                                     p->p_pid, (u_long)(uintfptr_t)addr, data);
1168                                 break;
1169                         }
1170                         break;
1171                 case PT_DETACH:
1172                         /*
1173                          * Reset the process parent.
1174                          *
1175                          * NB: This clears P_TRACED before reparenting
1176                          * a detached process back to its original
1177                          * parent.  Otherwise the debugee will be set
1178                          * as an orphan of the debugger.
1179                          */
1180                         p->p_flag &= ~(P_TRACED | P_WAITED);
1181                         if (p->p_oppid != p->p_pptr->p_pid) {
1182                                 PROC_LOCK(p->p_pptr);
1183                                 sigqueue_take(p->p_ksi);
1184                                 PROC_UNLOCK(p->p_pptr);
1185
1186                                 pp = proc_realparent(p);
1187                                 proc_reparent(p, pp, false);
1188                                 if (pp == initproc)
1189                                         p->p_sigparent = SIGCHLD;
1190                                 CTR3(KTR_PTRACE,
1191                             "PT_DETACH: pid %d reparented to pid %d, sig %d",
1192                                     p->p_pid, pp->p_pid, data);
1193                         } else
1194                                 CTR2(KTR_PTRACE, "PT_DETACH: pid %d, sig %d",
1195                                     p->p_pid, data);
1196                         p->p_ptevents = 0;
1197                         FOREACH_THREAD_IN_PROC(p, td3) {
1198                                 if ((td3->td_dbgflags & TDB_FSTP) != 0) {
1199                                         sigqueue_delete(&td3->td_sigqueue,
1200                                             SIGSTOP);
1201                                 }
1202                                 td3->td_dbgflags &= ~(TDB_XSIG | TDB_FSTP |
1203                                     TDB_SUSPEND);
1204                         }
1205
1206                         if ((p->p_flag2 & P2_PTRACE_FSTP) != 0) {
1207                                 sigqueue_delete(&p->p_sigqueue, SIGSTOP);
1208                                 p->p_flag2 &= ~P2_PTRACE_FSTP;
1209                         }
1210
1211                         /* should we send SIGCHLD? */
1212                         /* childproc_continued(p); */
1213                         break;
1214                 }
1215
1216                 sx_xunlock(&proctree_lock);
1217                 proctree_locked = 0;
1218
1219         sendsig:
1220                 MPASS(proctree_locked == 0);
1221
1222                 /*
1223                  * Clear the pending event for the thread that just
1224                  * reported its event (p_xthread).  This may not be
1225                  * the thread passed to PT_CONTINUE, PT_STEP, etc. if
1226                  * the debugger is resuming a different thread.
1227                  *
1228                  * Deliver any pending signal via the reporting thread.
1229                  */
1230                 MPASS(p->p_xthread != NULL);
1231                 p->p_xthread->td_dbgflags &= ~TDB_XSIG;
1232                 p->p_xthread->td_xsig = data;
1233                 p->p_xthread = NULL;
1234                 p->p_xsig = data;
1235
1236                 /*
1237                  * P_WKILLED is insurance that a PT_KILL/SIGKILL
1238                  * always works immediately, even if another thread is
1239                  * unsuspended first and attempts to handle a
1240                  * different signal or if the POSIX.1b style signal
1241                  * queue cannot accommodate any new signals.
1242                  */
1243                 if (data == SIGKILL)
1244                         proc_wkilled(p);
1245
1246                 /*
1247                  * Unsuspend all threads.  To leave a thread
1248                  * suspended, use PT_SUSPEND to suspend it before
1249                  * continuing the process.
1250                  */
1251                 PROC_SLOCK(p);
1252                 p->p_flag &= ~(P_STOPPED_TRACE | P_STOPPED_SIG | P_WAITED);
1253                 thread_unsuspend(p);
1254                 PROC_SUNLOCK(p);
1255                 break;
1256
1257         case PT_WRITE_I:
1258         case PT_WRITE_D:
1259                 td2->td_dbgflags |= TDB_USERWR;
1260                 PROC_UNLOCK(p);
1261                 error = 0;
1262                 if (proc_writemem(td, p, (off_t)(uintptr_t)addr, &data,
1263                     sizeof(int)) != sizeof(int))
1264                         error = ENOMEM;
1265                 else
1266                         CTR3(KTR_PTRACE, "PT_WRITE: pid %d: %p <= %#x",
1267                             p->p_pid, addr, data);
1268                 PROC_LOCK(p);
1269                 break;
1270
1271         case PT_READ_I:
1272         case PT_READ_D:
1273                 PROC_UNLOCK(p);
1274                 error = tmp = 0;
1275                 if (proc_readmem(td, p, (off_t)(uintptr_t)addr, &tmp,
1276                     sizeof(int)) != sizeof(int))
1277                         error = ENOMEM;
1278                 else
1279                         CTR3(KTR_PTRACE, "PT_READ: pid %d: %p >= %#x",
1280                             p->p_pid, addr, tmp);
1281                 td->td_retval[0] = tmp;
1282                 PROC_LOCK(p);
1283                 break;
1284
1285         case PT_IO:
1286 #ifdef COMPAT_FREEBSD32
1287                 if (wrap32) {
1288                         piod32 = addr;
1289                         iov.iov_base = (void *)(uintptr_t)piod32->piod_addr;
1290                         iov.iov_len = piod32->piod_len;
1291                         uio.uio_offset = (off_t)(uintptr_t)piod32->piod_offs;
1292                         uio.uio_resid = piod32->piod_len;
1293                 } else
1294 #endif
1295                 {
1296                         piod = addr;
1297                         iov.iov_base = piod->piod_addr;
1298                         iov.iov_len = piod->piod_len;
1299                         uio.uio_offset = (off_t)(uintptr_t)piod->piod_offs;
1300                         uio.uio_resid = piod->piod_len;
1301                 }
1302                 uio.uio_iov = &iov;
1303                 uio.uio_iovcnt = 1;
1304                 uio.uio_segflg = UIO_USERSPACE;
1305                 uio.uio_td = td;
1306 #ifdef COMPAT_FREEBSD32
1307                 tmp = wrap32 ? piod32->piod_op : piod->piod_op;
1308 #else
1309                 tmp = piod->piod_op;
1310 #endif
1311                 switch (tmp) {
1312                 case PIOD_READ_D:
1313                 case PIOD_READ_I:
1314                         CTR3(KTR_PTRACE, "PT_IO: pid %d: READ (%p, %#x)",
1315                             p->p_pid, (uintptr_t)uio.uio_offset, uio.uio_resid);
1316                         uio.uio_rw = UIO_READ;
1317                         break;
1318                 case PIOD_WRITE_D:
1319                 case PIOD_WRITE_I:
1320                         CTR3(KTR_PTRACE, "PT_IO: pid %d: WRITE (%p, %#x)",
1321                             p->p_pid, (uintptr_t)uio.uio_offset, uio.uio_resid);
1322                         td2->td_dbgflags |= TDB_USERWR;
1323                         uio.uio_rw = UIO_WRITE;
1324                         break;
1325                 default:
1326                         error = EINVAL;
1327                         goto out;
1328                 }
1329                 PROC_UNLOCK(p);
1330                 error = proc_rwmem(p, &uio);
1331 #ifdef COMPAT_FREEBSD32
1332                 if (wrap32)
1333                         piod32->piod_len -= uio.uio_resid;
1334                 else
1335 #endif
1336                         piod->piod_len -= uio.uio_resid;
1337                 PROC_LOCK(p);
1338                 break;
1339
1340         case PT_KILL:
1341                 CTR1(KTR_PTRACE, "PT_KILL: pid %d", p->p_pid);
1342                 data = SIGKILL;
1343                 goto sendsig;   /* in PT_CONTINUE above */
1344
1345         case PT_SETREGS:
1346                 CTR2(KTR_PTRACE, "PT_SETREGS: tid %d (pid %d)", td2->td_tid,
1347                     p->p_pid);
1348                 td2->td_dbgflags |= TDB_USERWR;
1349                 error = PROC_WRITE(regs, td2, addr);
1350                 break;
1351
1352         case PT_GETREGS:
1353                 CTR2(KTR_PTRACE, "PT_GETREGS: tid %d (pid %d)", td2->td_tid,
1354                     p->p_pid);
1355                 error = PROC_READ(regs, td2, addr);
1356                 break;
1357
1358         case PT_SETFPREGS:
1359                 CTR2(KTR_PTRACE, "PT_SETFPREGS: tid %d (pid %d)", td2->td_tid,
1360                     p->p_pid);
1361                 td2->td_dbgflags |= TDB_USERWR;
1362                 error = PROC_WRITE(fpregs, td2, addr);
1363                 break;
1364
1365         case PT_GETFPREGS:
1366                 CTR2(KTR_PTRACE, "PT_GETFPREGS: tid %d (pid %d)", td2->td_tid,
1367                     p->p_pid);
1368                 error = PROC_READ(fpregs, td2, addr);
1369                 break;
1370
1371         case PT_SETDBREGS:
1372                 CTR2(KTR_PTRACE, "PT_SETDBREGS: tid %d (pid %d)", td2->td_tid,
1373                     p->p_pid);
1374                 td2->td_dbgflags |= TDB_USERWR;
1375                 error = PROC_WRITE(dbregs, td2, addr);
1376                 break;
1377
1378         case PT_GETDBREGS:
1379                 CTR2(KTR_PTRACE, "PT_GETDBREGS: tid %d (pid %d)", td2->td_tid,
1380                     p->p_pid);
1381                 error = PROC_READ(dbregs, td2, addr);
1382                 break;
1383
1384         case PT_LWPINFO:
1385                 if (data <= 0 ||
1386 #ifdef COMPAT_FREEBSD32
1387                     (!wrap32 && data > sizeof(*pl)) ||
1388                     (wrap32 && data > sizeof(*pl32))) {
1389 #else
1390                     data > sizeof(*pl)) {
1391 #endif
1392                         error = EINVAL;
1393                         break;
1394                 }
1395 #ifdef COMPAT_FREEBSD32
1396                 if (wrap32) {
1397                         pl = &r.pl;
1398                         pl32 = addr;
1399                 } else
1400 #endif
1401                 pl = addr;
1402                 bzero(pl, sizeof(*pl));
1403                 pl->pl_lwpid = td2->td_tid;
1404                 pl->pl_event = PL_EVENT_NONE;
1405                 pl->pl_flags = 0;
1406                 if (td2->td_dbgflags & TDB_XSIG) {
1407                         pl->pl_event = PL_EVENT_SIGNAL;
1408                         if (td2->td_si.si_signo != 0 &&
1409 #ifdef COMPAT_FREEBSD32
1410                             ((!wrap32 && data >= offsetof(struct ptrace_lwpinfo,
1411                             pl_siginfo) + sizeof(pl->pl_siginfo)) ||
1412                             (wrap32 && data >= offsetof(struct ptrace_lwpinfo32,
1413                             pl_siginfo) + sizeof(struct siginfo32)))
1414 #else
1415                             data >= offsetof(struct ptrace_lwpinfo, pl_siginfo)
1416                             + sizeof(pl->pl_siginfo)
1417 #endif
1418                         ){
1419                                 pl->pl_flags |= PL_FLAG_SI;
1420                                 pl->pl_siginfo = td2->td_si;
1421                         }
1422                 }
1423                 if (td2->td_dbgflags & TDB_SCE)
1424                         pl->pl_flags |= PL_FLAG_SCE;
1425                 else if (td2->td_dbgflags & TDB_SCX)
1426                         pl->pl_flags |= PL_FLAG_SCX;
1427                 if (td2->td_dbgflags & TDB_EXEC)
1428                         pl->pl_flags |= PL_FLAG_EXEC;
1429                 if (td2->td_dbgflags & TDB_FORK) {
1430                         pl->pl_flags |= PL_FLAG_FORKED;
1431                         pl->pl_child_pid = td2->td_dbg_forked;
1432                         if (td2->td_dbgflags & TDB_VFORK)
1433                                 pl->pl_flags |= PL_FLAG_VFORKED;
1434                 } else if ((td2->td_dbgflags & (TDB_SCX | TDB_VFORK)) ==
1435                     TDB_VFORK)
1436                         pl->pl_flags |= PL_FLAG_VFORK_DONE;
1437                 if (td2->td_dbgflags & TDB_CHILD)
1438                         pl->pl_flags |= PL_FLAG_CHILD;
1439                 if (td2->td_dbgflags & TDB_BORN)
1440                         pl->pl_flags |= PL_FLAG_BORN;
1441                 if (td2->td_dbgflags & TDB_EXIT)
1442                         pl->pl_flags |= PL_FLAG_EXITED;
1443                 pl->pl_sigmask = td2->td_sigmask;
1444                 pl->pl_siglist = td2->td_siglist;
1445                 strcpy(pl->pl_tdname, td2->td_name);
1446                 if ((td2->td_dbgflags & (TDB_SCE | TDB_SCX)) != 0) {
1447                         pl->pl_syscall_code = td2->td_sa.code;
1448                         pl->pl_syscall_narg = td2->td_sa.narg;
1449                 } else {
1450                         pl->pl_syscall_code = 0;
1451                         pl->pl_syscall_narg = 0;
1452                 }
1453 #ifdef COMPAT_FREEBSD32
1454                 if (wrap32)
1455                         ptrace_lwpinfo_to32(pl, pl32);
1456 #endif
1457                 CTR6(KTR_PTRACE,
1458     "PT_LWPINFO: tid %d (pid %d) event %d flags %#x child pid %d syscall %d",
1459                     td2->td_tid, p->p_pid, pl->pl_event, pl->pl_flags,
1460                     pl->pl_child_pid, pl->pl_syscall_code);
1461                 break;
1462
1463         case PT_GETNUMLWPS:
1464                 CTR2(KTR_PTRACE, "PT_GETNUMLWPS: pid %d: %d threads", p->p_pid,
1465                     p->p_numthreads);
1466                 td->td_retval[0] = p->p_numthreads;
1467                 break;
1468
1469         case PT_GETLWPLIST:
1470                 CTR3(KTR_PTRACE, "PT_GETLWPLIST: pid %d: data %d, actual %d",
1471                     p->p_pid, data, p->p_numthreads);
1472                 if (data <= 0) {
1473                         error = EINVAL;
1474                         break;
1475                 }
1476                 num = imin(p->p_numthreads, data);
1477                 PROC_UNLOCK(p);
1478                 buf = malloc(num * sizeof(lwpid_t), M_TEMP, M_WAITOK);
1479                 tmp = 0;
1480                 PROC_LOCK(p);
1481                 FOREACH_THREAD_IN_PROC(p, td2) {
1482                         if (tmp >= num)
1483                                 break;
1484                         buf[tmp++] = td2->td_tid;
1485                 }
1486                 PROC_UNLOCK(p);
1487                 error = copyout(buf, addr, tmp * sizeof(lwpid_t));
1488                 free(buf, M_TEMP);
1489                 if (!error)
1490                         td->td_retval[0] = tmp;
1491                 PROC_LOCK(p);
1492                 break;
1493
1494         case PT_VM_TIMESTAMP:
1495                 CTR2(KTR_PTRACE, "PT_VM_TIMESTAMP: pid %d: timestamp %d",
1496                     p->p_pid, p->p_vmspace->vm_map.timestamp);
1497                 td->td_retval[0] = p->p_vmspace->vm_map.timestamp;
1498                 break;
1499
1500         case PT_VM_ENTRY:
1501                 PROC_UNLOCK(p);
1502 #ifdef COMPAT_FREEBSD32
1503                 if (wrap32)
1504                         error = ptrace_vm_entry32(td, p, addr);
1505                 else
1506 #endif
1507                 error = ptrace_vm_entry(td, p, addr);
1508                 PROC_LOCK(p);
1509                 break;
1510
1511         default:
1512 #ifdef __HAVE_PTRACE_MACHDEP
1513                 if (req >= PT_FIRSTMACH) {
1514                         PROC_UNLOCK(p);
1515                         error = cpu_ptrace(td2, req, addr, data);
1516                         PROC_LOCK(p);
1517                 } else
1518 #endif
1519                         /* Unknown request. */
1520                         error = EINVAL;
1521                 break;
1522         }
1523
1524 out:
1525         /* Drop our hold on this process now that the request has completed. */
1526         _PRELE(p);
1527 fail:
1528         PROC_UNLOCK(p);
1529         if (proctree_locked)
1530                 sx_xunlock(&proctree_lock);
1531         return (error);
1532 }
1533 #undef PROC_READ
1534 #undef PROC_WRITE
1535
1536 /*
1537  * Stop a process because of a debugging event;
1538  * stay stopped until p->p_step is cleared
1539  * (cleared by PIOCCONT in procfs).
1540  */
1541 void
1542 stopevent(struct proc *p, unsigned int event, unsigned int val)
1543 {
1544
1545         PROC_LOCK_ASSERT(p, MA_OWNED);
1546         p->p_step = 1;
1547         CTR3(KTR_PTRACE, "stopevent: pid %d event %u val %u", p->p_pid, event,
1548             val);
1549         do {
1550                 if (event != S_EXIT)
1551                         p->p_xsig = val;
1552                 p->p_xthread = NULL;
1553                 p->p_stype = event;     /* Which event caused the stop? */
1554                 wakeup(&p->p_stype);    /* Wake up any PIOCWAIT'ing procs */
1555                 msleep(&p->p_step, &p->p_mtx, PWAIT, "stopevent", 0);
1556         } while (p->p_step);
1557 }