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