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_hold(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                 entry = map->header.next;
 386                 index = 0;
 387                 while (index < pve->pve_entry && entry != &map->header) {
 388                         entry = entry->next;
 389                         index++;
 390                 }
 391                 if (index != pve->pve_entry) {
 392                         error = EINVAL;
 393                         break;
 394                 }
 395                 KASSERT((map->header.eflags & MAP_ENTRY_IS_SUB_MAP) == 0,
 396                     ("Submap in map header"));
 397                 while ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) != 0) {
 398                         entry = entry->next;
 399                         index++;
 400                 }
 401                 if (entry == &map->header) {
 402                         error = ENOENT;
 403                         break;
 404                 }
 405
 406                 /* We got an entry. */
 407                 pve->pve_entry = index + 1;
 408                 pve->pve_timestamp = map->timestamp;
 409                 pve->pve_start = entry->start;
 410                 pve->pve_end = entry->end - 1;
 411                 pve->pve_offset = entry->offset;
 412                 pve->pve_prot = entry->protection;
 413
 414                 /* Backing object's path needed? */
 415                 if (pve->pve_pathlen == 0)
 416                         break;
 417
 418                 pathlen = pve->pve_pathlen;
 419                 pve->pve_pathlen = 0;
 420
 421                 obj = entry->object.vm_object;
 422                 if (obj != NULL)
 423                         VM_OBJECT_RLOCK(obj);
 424         } while (0);
 425
 426         vm_map_unlock_read(map);
 427
 428         pve->pve_fsid = VNOVAL;
 429         pve->pve_fileid = VNOVAL;
 430
 431         if (error == 0 && obj != NULL) {
 432                 lobj = obj;
 433                 for (tobj = obj; tobj != NULL; tobj = tobj->backing_object) {
 434                         if (tobj != obj)
 435                                 VM_OBJECT_RLOCK(tobj);
 436                         if (lobj != obj)
 437                                 VM_OBJECT_RUNLOCK(lobj);
 438                         lobj = tobj;
 439                         pve->pve_offset += tobj->backing_object_offset;
 440                 }
 441                 vp = vm_object_vnode(lobj);
 442                 if (vp != NULL)
 443                         vref(vp);
 444                 if (lobj != obj)
 445                         VM_OBJECT_RUNLOCK(lobj);
 446                 VM_OBJECT_RUNLOCK(obj);
 447
 448                 if (vp != NULL) {
 449                         freepath = NULL;
 450                         fullpath = NULL;
 451                         vn_fullpath(td, vp, &fullpath, &freepath);
 452                         vn_lock(vp, LK_SHARED | LK_RETRY);
 453                         if (VOP_GETATTR(vp, &vattr, td->td_ucred) == 0) {
 454                                 pve->pve_fileid = vattr.va_fileid;
 455                                 pve->pve_fsid = vattr.va_fsid;
 456                         }
 457                         vput(vp);
 458
 459                         if (fullpath != NULL) {
 460                                 pve->pve_pathlen = strlen(fullpath) + 1;
 461                                 if (pve->pve_pathlen <= pathlen) {
 462                                         error = copyout(fullpath, pve->pve_path,
 463                                             pve->pve_pathlen);
 464                                 } else
 465                                         error = ENAMETOOLONG;
 466                         }
 467                         if (freepath != NULL)
 468                                 free(freepath, M_TEMP);
 469                 }
 470         }
 471         vmspace_free(vm);
 472         if (error == 0)
 473                 CTR3(KTR_PTRACE, "PT_VM_ENTRY: pid %d, entry %d, start %p",
 474                     p->p_pid, pve->pve_entry, pve->pve_start);
 475
 476         return (error);
 477 }
 478
 479 #ifdef COMPAT_FREEBSD32
 480 static int
 481 ptrace_vm_entry32(struct thread *td, struct proc *p,
 482     struct ptrace_vm_entry32 *pve32)
 483 {
 484         struct ptrace_vm_entry pve;
 485         int error;
 486
 487         pve.pve_entry = pve32->pve_entry;
 488         pve.pve_pathlen = pve32->pve_pathlen;
 489         pve.pve_path = (void *)(uintptr_t)pve32->pve_path;
 490
 491         error = ptrace_vm_entry(td, p, &pve);
 492         if (error == 0) {
 493                 pve32->pve_entry = pve.pve_entry;
 494                 pve32->pve_timestamp = pve.pve_timestamp;
 495                 pve32->pve_start = pve.pve_start;
 496                 pve32->pve_end = pve.pve_end;
 497                 pve32->pve_offset = pve.pve_offset;
 498                 pve32->pve_prot = pve.pve_prot;
 499                 pve32->pve_fileid = pve.pve_fileid;
 500                 pve32->pve_fsid = pve.pve_fsid;
 501         }
 502
 503         pve32->pve_pathlen = pve.pve_pathlen;
 504         return (error);
 505 }
 506
 507 static void
 508 ptrace_lwpinfo_to32(const struct ptrace_lwpinfo *pl,
 509     struct ptrace_lwpinfo32 *pl32)
 510 {
 511
 512         bzero(pl32, sizeof(*pl32));
 513         pl32->pl_lwpid = pl->pl_lwpid;
 514         pl32->pl_event = pl->pl_event;
 515         pl32->pl_flags = pl->pl_flags;
 516         pl32->pl_sigmask = pl->pl_sigmask;
 517         pl32->pl_siglist = pl->pl_siglist;
 518         siginfo_to_siginfo32(&pl->pl_siginfo, &pl32->pl_siginfo);
 519         strcpy(pl32->pl_tdname, pl->pl_tdname);
 520         pl32->pl_child_pid = pl->pl_child_pid;
 521         pl32->pl_syscall_code = pl->pl_syscall_code;
 522         pl32->pl_syscall_narg = pl->pl_syscall_narg;
 523 }
 524
 525 static void
 526 ptrace_sc_ret_to32(const struct ptrace_sc_ret *psr,
 527     struct ptrace_sc_ret32 *psr32)
 528 {
 529
 530         bzero(psr32, sizeof(*psr32));
 531         psr32->sr_retval[0] = psr->sr_retval[0];
 532         psr32->sr_retval[1] = psr->sr_retval[1];
 533         psr32->sr_error = psr->sr_error;
 534 }
 535 #endif /* COMPAT_FREEBSD32 */
 536
 537 /*
 538  * Process debugging system call.
 539  */
 540 #ifndef _SYS_SYSPROTO_H_
 541 struct ptrace_args {
 542         int     req;
 543         pid_t   pid;
 544         caddr_t addr;
 545         int     data;
 546 };
 547 #endif
 548
 549 #ifdef COMPAT_FREEBSD32
 550 /*
 551  * This CPP subterfuge is to try and reduce the number of ifdefs in
 552  * the body of the code.
 553  *   COPYIN(uap->addr, &r.reg, sizeof r.reg);
 554  * becomes either:
 555  *   copyin(uap->addr, &r.reg, sizeof r.reg);
 556  * or
 557  *   copyin(uap->addr, &r.reg32, sizeof r.reg32);
 558  * .. except this is done at runtime.
 559  */
 560 #define BZERO(a, s)             wrap32 ? \
 561         bzero(a ## 32, s ## 32) : \
 562         bzero(a, s)
 563 #define COPYIN(u, k, s)         wrap32 ? \
 564         copyin(u, k ## 32, s ## 32) : \
 565         copyin(u, k, s)
 566 #define COPYOUT(k, u, s)        wrap32 ? \
 567         copyout(k ## 32, u, s ## 32) : \
 568         copyout(k, u, s)
 569 #else
 570 #define BZERO(a, s)             bzero(a, s)
 571 #define COPYIN(u, k, s)         copyin(u, k, s)
 572 #define COPYOUT(k, u, s)        copyout(k, u, s)
 573 #endif
 574 int
 575 sys_ptrace(struct thread *td, struct ptrace_args *uap)
 576 {
 577         /*
 578          * XXX this obfuscation is to reduce stack usage, but the register
 579          * structs may be too large to put on the stack anyway.
 580          */
 581         union {
 582                 struct ptrace_io_desc piod;
 583                 struct ptrace_lwpinfo pl;
 584                 struct ptrace_vm_entry pve;
 585                 struct dbreg dbreg;
 586                 struct fpreg fpreg;
 587                 struct reg reg;
 588 #ifdef COMPAT_FREEBSD32
 589                 struct dbreg32 dbreg32;
 590                 struct fpreg32 fpreg32;
 591                 struct reg32 reg32;
 592                 struct ptrace_io_desc32 piod32;
 593                 struct ptrace_lwpinfo32 pl32;
 594                 struct ptrace_vm_entry32 pve32;
 595 #endif
 596                 char args[sizeof(td->td_sa.args)];
 597                 struct ptrace_sc_ret psr;
 598                 int ptevents;
 599         } r;
 600         void *addr;
 601         int error = 0;
 602 #ifdef COMPAT_FREEBSD32
 603         int wrap32 = 0;
 604
 605         if (SV_CURPROC_FLAG(SV_ILP32))
 606                 wrap32 = 1;
 607 #endif
 608         AUDIT_ARG_PID(uap->pid);
 609         AUDIT_ARG_CMD(uap->req);
 610         AUDIT_ARG_VALUE(uap->data);
 611         addr = &r;
 612         switch (uap->req) {
 613         case PT_GET_EVENT_MASK:
 614         case PT_LWPINFO:
 615         case PT_GET_SC_ARGS:
 616         case PT_GET_SC_RET:
 617                 break;
 618         case PT_GETREGS:
 619                 BZERO(&r.reg, sizeof r.reg);
 620                 break;
 621         case PT_GETFPREGS:
 622                 BZERO(&r.fpreg, sizeof r.fpreg);
 623                 break;
 624         case PT_GETDBREGS:
 625                 BZERO(&r.dbreg, sizeof r.dbreg);
 626                 break;
 627         case PT_SETREGS:
 628                 error = COPYIN(uap->addr, &r.reg, sizeof r.reg);
 629                 break;
 630         case PT_SETFPREGS:
 631                 error = COPYIN(uap->addr, &r.fpreg, sizeof r.fpreg);
 632                 break;
 633         case PT_SETDBREGS:
 634                 error = COPYIN(uap->addr, &r.dbreg, sizeof r.dbreg);
 635                 break;
 636         case PT_SET_EVENT_MASK:
 637                 if (uap->data != sizeof(r.ptevents))
 638                         error = EINVAL;
 639                 else
 640                         error = copyin(uap->addr, &r.ptevents, uap->data);
 641                 break;
 642         case PT_IO:
 643                 error = COPYIN(uap->addr, &r.piod, sizeof r.piod);
 644                 break;
 645         case PT_VM_ENTRY:
 646                 error = COPYIN(uap->addr, &r.pve, sizeof r.pve);
 647                 break;
 648         default:
 649                 addr = uap->addr;
 650                 break;
 651         }
 652         if (error)
 653                 return (error);
 654
 655         error = kern_ptrace(td, uap->req, uap->pid, addr, uap->data);
 656         if (error)
 657                 return (error);
 658
 659         switch (uap->req) {
 660         case PT_VM_ENTRY:
 661                 error = COPYOUT(&r.pve, uap->addr, sizeof r.pve);
 662                 break;
 663         case PT_IO:
 664                 error = COPYOUT(&r.piod, uap->addr, sizeof r.piod);
 665                 break;
 666         case PT_GETREGS:
 667                 error = COPYOUT(&r.reg, uap->addr, sizeof r.reg);
 668                 break;
 669         case PT_GETFPREGS:
 670                 error = COPYOUT(&r.fpreg, uap->addr, sizeof r.fpreg);
 671                 break;
 672         case PT_GETDBREGS:
 673                 error = COPYOUT(&r.dbreg, uap->addr, sizeof r.dbreg);
 674                 break;
 675         case PT_GET_EVENT_MASK:
 676                 /* NB: The size in uap->data is validated in kern_ptrace(). */
 677                 error = copyout(&r.ptevents, uap->addr, uap->data);
 678                 break;
 679         case PT_LWPINFO:
 680                 /* NB: The size in uap->data is validated in kern_ptrace(). */
 681                 error = copyout(&r.pl, uap->addr, uap->data);
 682                 break;
 683         case PT_GET_SC_ARGS:
 684                 error = copyout(r.args, uap->addr, MIN(uap->data,
 685                     sizeof(r.args)));
 686                 break;
 687         case PT_GET_SC_RET:
 688                 error = copyout(&r.psr, uap->addr, MIN(uap->data,
 689                     sizeof(r.psr)));
 690                 break;
 691         }
 692
 693         return (error);
 694 }
 695 #undef COPYIN
 696 #undef COPYOUT
 697 #undef BZERO
 698
 699 #ifdef COMPAT_FREEBSD32
 700 /*
 701  *   PROC_READ(regs, td2, addr);
 702  * becomes either:
 703  *   proc_read_regs(td2, addr);
 704  * or
 705  *   proc_read_regs32(td2, addr);
 706  * .. except this is done at runtime.  There is an additional
 707  * complication in that PROC_WRITE disallows 32 bit consumers
 708  * from writing to 64 bit address space targets.
 709  */
 710 #define PROC_READ(w, t, a)      wrap32 ? \
 711         proc_read_ ## w ## 32(t, a) : \
 712         proc_read_ ## w (t, a)
 713 #define PROC_WRITE(w, t, a)     wrap32 ? \
 714         (safe ? proc_write_ ## w ## 32(t, a) : EINVAL ) : \
 715         proc_write_ ## w (t, a)
 716 #else
 717 #define PROC_READ(w, t, a)      proc_read_ ## w (t, a)
 718 #define PROC_WRITE(w, t, a)     proc_write_ ## w (t, a)
 719 #endif
 720
 721 void
 722 proc_set_traced(struct proc *p, bool stop)
 723 {
 724
 725         sx_assert(&proctree_lock, SX_XLOCKED);
 726         PROC_LOCK_ASSERT(p, MA_OWNED);
 727         p->p_flag |= P_TRACED;
 728         if (stop)
 729                 p->p_flag2 |= P2_PTRACE_FSTP;
 730         p->p_ptevents = PTRACE_DEFAULT;
 731 }
 732
 733 int
 734 kern_ptrace(struct thread *td, int req, pid_t pid, void *addr, int data)
 735 {
 736         struct iovec iov;
 737         struct uio uio;
 738         struct proc *curp, *p, *pp;
 739         struct thread *td2 = NULL, *td3;
 740         struct ptrace_io_desc *piod = NULL;
 741         struct ptrace_lwpinfo *pl;
 742         struct ptrace_sc_ret *psr;
 743         int error, num, tmp;
 744         int proctree_locked = 0;
 745         lwpid_t tid = 0, *buf;
 746 #ifdef COMPAT_FREEBSD32
 747         int wrap32 = 0, safe = 0;
 748         struct ptrace_io_desc32 *piod32 = NULL;
 749         struct ptrace_lwpinfo32 *pl32 = NULL;
 750         struct ptrace_sc_ret32 *psr32 = NULL;
 751         union {
 752                 struct ptrace_lwpinfo pl;
 753                 struct ptrace_sc_ret psr;
 754         } r;
 755 #endif
 756
 757         curp = td->td_proc;
 758
 759         /* Lock proctree before locking the process. */
 760         switch (req) {
 761         case PT_TRACE_ME:
 762         case PT_ATTACH:
 763         case PT_STEP:
 764         case PT_CONTINUE:
 765         case PT_TO_SCE:
 766         case PT_TO_SCX:
 767         case PT_SYSCALL:
 768         case PT_FOLLOW_FORK:
 769         case PT_LWP_EVENTS:
 770         case PT_GET_EVENT_MASK:
 771         case PT_SET_EVENT_MASK:
 772         case PT_DETACH:
 773         case PT_GET_SC_ARGS:
 774                 sx_xlock(&proctree_lock);
 775                 proctree_locked = 1;
 776                 break;
 777         default:
 778                 break;
 779         }
 780
 781         if (req == PT_TRACE_ME) {
 782                 p = td->td_proc;
 783                 PROC_LOCK(p);
 784         } else {
 785                 if (pid <= PID_MAX) {
 786                         if ((p = pfind(pid)) == NULL) {
 787                                 if (proctree_locked)
 788                                         sx_xunlock(&proctree_lock);
 789                                 return (ESRCH);
 790                         }
 791                 } else {
 792                         td2 = tdfind(pid, -1);
 793                         if (td2 == NULL) {
 794                                 if (proctree_locked)
 795                                         sx_xunlock(&proctree_lock);
 796                                 return (ESRCH);
 797                         }
 798                         p = td2->td_proc;
 799                         tid = pid;
 800                         pid = p->p_pid;
 801                 }
 802         }
 803         AUDIT_ARG_PROCESS(p);
 804
 805         if ((p->p_flag & P_WEXIT) != 0) {
 806                 error = ESRCH;
 807                 goto fail;
 808         }
 809         if ((error = p_cansee(td, p)) != 0)
 810                 goto fail;
 811
 812         if ((error = p_candebug(td, p)) != 0)
 813                 goto fail;
 814
 815         /*
 816          * System processes can't be debugged.
 817          */
 818         if ((p->p_flag & P_SYSTEM) != 0) {
 819                 error = EINVAL;
 820                 goto fail;
 821         }
 822
 823         if (tid == 0) {
 824                 if ((p->p_flag & P_STOPPED_TRACE) != 0) {
 825                         KASSERT(p->p_xthread != NULL, ("NULL p_xthread"));
 826                         td2 = p->p_xthread;
 827                 } else {
 828                         td2 = FIRST_THREAD_IN_PROC(p);
 829                 }
 830                 tid = td2->td_tid;
 831         }
 832
 833 #ifdef COMPAT_FREEBSD32
 834         /*
 835          * Test if we're a 32 bit client and what the target is.
 836          * Set the wrap controls accordingly.
 837          */
 838         if (SV_CURPROC_FLAG(SV_ILP32)) {
 839                 if (SV_PROC_FLAG(td2->td_proc, SV_ILP32))
 840                         safe = 1;
 841                 wrap32 = 1;
 842         }
 843 #endif
 844         /*
 845          * Permissions check
 846          */
 847         switch (req) {
 848         case PT_TRACE_ME:
 849                 /*
 850                  * Always legal, when there is a parent process which
 851                  * could trace us.  Otherwise, reject.
 852                  */
 853                 if ((p->p_flag & P_TRACED) != 0) {
 854                         error = EBUSY;
 855                         goto fail;
 856                 }
 857                 if (p->p_pptr == initproc) {
 858                         error = EPERM;
 859                         goto fail;
 860                 }
 861                 break;
 862
 863         case PT_ATTACH:
 864                 /* Self */
 865                 if (p == td->td_proc) {
 866                         error = EINVAL;
 867                         goto fail;
 868                 }
 869
 870                 /* Already traced */
 871                 if (p->p_flag & P_TRACED) {
 872                         error = EBUSY;
 873                         goto fail;
 874                 }
 875
 876                 /* Can't trace an ancestor if you're being traced. */
 877                 if (curp->p_flag & P_TRACED) {
 878                         for (pp = curp->p_pptr; pp != NULL; pp = pp->p_pptr) {
 879                                 if (pp == p) {
 880                                         error = EINVAL;
 881                                         goto fail;
 882                                 }
 883                         }
 884                 }
 885
 886
 887                 /* OK */
 888                 break;
 889
 890         case PT_CLEARSTEP:
 891                 /* Allow thread to clear single step for itself */
 892                 if (td->td_tid == tid)
 893                         break;
 894
 895                 /* FALLTHROUGH */
 896         default:
 897                 /* not being traced... */
 898                 if ((p->p_flag & P_TRACED) == 0) {
 899                         error = EPERM;
 900                         goto fail;
 901                 }
 902
 903                 /* not being traced by YOU */
 904                 if (p->p_pptr != td->td_proc) {
 905                         error = EBUSY;
 906                         goto fail;
 907                 }
 908
 909                 /* not currently stopped */
 910                 if ((p->p_flag & P_STOPPED_TRACE) == 0 ||
 911                     p->p_suspcount != p->p_numthreads  ||
 912                     (p->p_flag & P_WAITED) == 0) {
 913                         error = EBUSY;
 914                         goto fail;
 915                 }
 916
 917                 /* OK */
 918                 break;
 919         }
 920
 921         /* Keep this process around until we finish this request. */
 922         _PHOLD(p);
 923
 924 #ifdef FIX_SSTEP
 925         /*
 926          * Single step fixup ala procfs
 927          */
 928         FIX_SSTEP(td2);
 929 #endif
 930
 931         /*
 932          * Actually do the requests
 933          */
 934
 935         td->td_retval[0] = 0;
 936
 937         switch (req) {
 938         case PT_TRACE_ME:
 939                 /* set my trace flag and "owner" so it can read/write me */
 940                 proc_set_traced(p, false);
 941                 if (p->p_flag & P_PPWAIT)
 942                         p->p_flag |= P_PPTRACE;
 943                 CTR1(KTR_PTRACE, "PT_TRACE_ME: pid %d", p->p_pid);
 944                 break;
 945
 946         case PT_ATTACH:
 947                 /* security check done above */
 948                 /*
 949                  * It would be nice if the tracing relationship was separate
 950                  * from the parent relationship but that would require
 951                  * another set of links in the proc struct or for "wait"
 952                  * to scan the entire proc table.  To make life easier,
 953                  * we just re-parent the process we're trying to trace.
 954                  * The old parent is remembered so we can put things back
 955                  * on a "detach".
 956                  */
 957                 proc_set_traced(p, true);
 958                 proc_reparent(p, td->td_proc, false);
 959                 CTR2(KTR_PTRACE, "PT_ATTACH: pid %d, oppid %d", p->p_pid,
 960                     p->p_oppid);
 961
 962                 sx_xunlock(&proctree_lock);
 963                 proctree_locked = 0;
 964                 MPASS(p->p_xthread == NULL);
 965                 MPASS((p->p_flag & P_STOPPED_TRACE) == 0);
 966
 967                 /*
 968                  * If already stopped due to a stop signal, clear the
 969                  * existing stop before triggering a traced SIGSTOP.
 970                  */
 971                 if ((p->p_flag & P_STOPPED_SIG) != 0) {
 972                         PROC_SLOCK(p);
 973                         p->p_flag &= ~(P_STOPPED_SIG | P_WAITED);
 974                         thread_unsuspend(p);
 975                         PROC_SUNLOCK(p);
 976                 }
 977
 978                 kern_psignal(p, SIGSTOP);
 979                 break;
 980
 981         case PT_CLEARSTEP:
 982                 CTR2(KTR_PTRACE, "PT_CLEARSTEP: tid %d (pid %d)", td2->td_tid,
 983                     p->p_pid);
 984                 error = ptrace_clear_single_step(td2);
 985                 break;
 986
 987         case PT_SETSTEP:
 988                 CTR2(KTR_PTRACE, "PT_SETSTEP: tid %d (pid %d)", td2->td_tid,
 989                     p->p_pid);
 990                 error = ptrace_single_step(td2);
 991                 break;
 992
 993         case PT_SUSPEND:
 994                 CTR2(KTR_PTRACE, "PT_SUSPEND: tid %d (pid %d)", td2->td_tid,
 995                     p->p_pid);
 996                 td2->td_dbgflags |= TDB_SUSPEND;
 997                 thread_lock(td2);
 998                 td2->td_flags |= TDF_NEEDSUSPCHK;
 999                 thread_unlock(td2);
1000                 break;
1001
1002         case PT_RESUME:
1003                 CTR2(KTR_PTRACE, "PT_RESUME: tid %d (pid %d)", td2->td_tid,
1004                     p->p_pid);
1005                 td2->td_dbgflags &= ~TDB_SUSPEND;
1006                 break;
1007
1008         case PT_FOLLOW_FORK:
1009                 CTR3(KTR_PTRACE, "PT_FOLLOW_FORK: pid %d %s -> %s", p->p_pid,
1010                     p->p_ptevents & PTRACE_FORK ? "enabled" : "disabled",
1011                     data ? "enabled" : "disabled");
1012                 if (data)
1013                         p->p_ptevents |= PTRACE_FORK;
1014                 else
1015                         p->p_ptevents &= ~PTRACE_FORK;
1016                 break;
1017
1018         case PT_LWP_EVENTS:
1019                 CTR3(KTR_PTRACE, "PT_LWP_EVENTS: pid %d %s -> %s", p->p_pid,
1020                     p->p_ptevents & PTRACE_LWP ? "enabled" : "disabled",
1021                     data ? "enabled" : "disabled");
1022                 if (data)
1023                         p->p_ptevents |= PTRACE_LWP;
1024                 else
1025                         p->p_ptevents &= ~PTRACE_LWP;
1026                 break;
1027
1028         case PT_GET_EVENT_MASK:
1029                 if (data != sizeof(p->p_ptevents)) {
1030                         error = EINVAL;
1031                         break;
1032                 }
1033                 CTR2(KTR_PTRACE, "PT_GET_EVENT_MASK: pid %d mask %#x", p->p_pid,
1034                     p->p_ptevents);
1035                 *(int *)addr = p->p_ptevents;
1036                 break;
1037
1038         case PT_SET_EVENT_MASK:
1039                 if (data != sizeof(p->p_ptevents)) {
1040                         error = EINVAL;
1041                         break;
1042                 }
1043                 tmp = *(int *)addr;
1044                 if ((tmp & ~(PTRACE_EXEC | PTRACE_SCE | PTRACE_SCX |
1045                     PTRACE_FORK | PTRACE_LWP | PTRACE_VFORK)) != 0) {
1046                         error = EINVAL;
1047                         break;
1048                 }
1049                 CTR3(KTR_PTRACE, "PT_SET_EVENT_MASK: pid %d mask %#x -> %#x",
1050                     p->p_pid, p->p_ptevents, tmp);
1051                 p->p_ptevents = tmp;
1052                 break;
1053
1054         case PT_GET_SC_ARGS:
1055                 CTR1(KTR_PTRACE, "PT_GET_SC_ARGS: pid %d", p->p_pid);
1056                 if ((td2->td_dbgflags & (TDB_SCE | TDB_SCX)) == 0
1057 #ifdef COMPAT_FREEBSD32
1058                     || (wrap32 && !safe)
1059 #endif
1060                     ) {
1061                         error = EINVAL;
1062                         break;
1063                 }
1064                 bzero(addr, sizeof(td2->td_sa.args));
1065 #ifdef COMPAT_FREEBSD32
1066                 if (wrap32)
1067                         for (num = 0; num < nitems(td2->td_sa.args); num++)
1068                                 ((uint32_t *)addr)[num] = (uint32_t)
1069                                     td2->td_sa.args[num];
1070                 else
1071 #endif
1072                         bcopy(td2->td_sa.args, addr, td2->td_sa.narg *
1073                             sizeof(register_t));
1074                 break;
1075
1076         case PT_GET_SC_RET:
1077                 if ((td2->td_dbgflags & (TDB_SCX)) == 0
1078 #ifdef COMPAT_FREEBSD32
1079                     || (wrap32 && !safe)
1080 #endif
1081                     ) {
1082                         error = EINVAL;
1083                         break;
1084                 }
1085 #ifdef COMPAT_FREEBSD32
1086                 if (wrap32) {
1087                         psr = &r.psr;
1088                         psr32 = addr;
1089                 } else
1090 #endif
1091                 psr = addr;
1092                 bzero(psr, sizeof(*psr));
1093                 psr->sr_error = td2->td_errno;
1094                 if (psr->sr_error == 0) {
1095                         psr->sr_retval[0] = td2->td_retval[0];
1096                         psr->sr_retval[1] = td2->td_retval[1];
1097                 }
1098 #ifdef COMPAT_FREEBSD32
1099                 if (wrap32)
1100                         ptrace_sc_ret_to32(psr, psr32);
1101 #endif
1102                 CTR4(KTR_PTRACE,
1103                     "PT_GET_SC_RET: pid %d error %d retval %#lx,%#lx",
1104                     p->p_pid, psr->sr_error, psr->sr_retval[0],
1105                     psr->sr_retval[1]);
1106                 break;
1107
1108         case PT_STEP:
1109         case PT_CONTINUE:
1110         case PT_TO_SCE:
1111         case PT_TO_SCX:
1112         case PT_SYSCALL:
1113         case PT_DETACH:
1114                 /* Zero means do not send any signal */
1115                 if (data < 0 || data > _SIG_MAXSIG) {
1116                         error = EINVAL;
1117                         break;
1118                 }
1119
1120                 switch (req) {
1121                 case PT_STEP:
1122                         CTR3(KTR_PTRACE, "PT_STEP: tid %d (pid %d), sig = %d",
1123                             td2->td_tid, p->p_pid, data);
1124                         error = ptrace_single_step(td2);
1125                         if (error)
1126                                 goto out;
1127                         break;
1128                 case PT_CONTINUE:
1129                 case PT_TO_SCE:
1130                 case PT_TO_SCX:
1131                 case PT_SYSCALL:
1132                         if (addr != (void *)1) {
1133                                 error = ptrace_set_pc(td2,
1134                                     (u_long)(uintfptr_t)addr);
1135                                 if (error)
1136                                         goto out;
1137                         }
1138                         switch (req) {
1139                         case PT_TO_SCE:
1140                                 p->p_ptevents |= PTRACE_SCE;
1141                                 CTR4(KTR_PTRACE,
1142                     "PT_TO_SCE: pid %d, events = %#x, PC = %#lx, sig = %d",
1143                                     p->p_pid, p->p_ptevents,
1144                                     (u_long)(uintfptr_t)addr, data);
1145                                 break;
1146                         case PT_TO_SCX:
1147                                 p->p_ptevents |= PTRACE_SCX;
1148                                 CTR4(KTR_PTRACE,
1149                     "PT_TO_SCX: pid %d, events = %#x, PC = %#lx, sig = %d",
1150                                     p->p_pid, p->p_ptevents,
1151                                     (u_long)(uintfptr_t)addr, data);
1152                                 break;
1153                         case PT_SYSCALL:
1154                                 p->p_ptevents |= PTRACE_SYSCALL;
1155                                 CTR4(KTR_PTRACE,
1156                     "PT_SYSCALL: pid %d, events = %#x, PC = %#lx, sig = %d",
1157                                     p->p_pid, p->p_ptevents,
1158                                     (u_long)(uintfptr_t)addr, data);
1159                                 break;
1160                         case PT_CONTINUE:
1161                                 CTR3(KTR_PTRACE,
1162                                     "PT_CONTINUE: pid %d, PC = %#lx, sig = %d",
1163                                     p->p_pid, (u_long)(uintfptr_t)addr, data);
1164                                 break;
1165                         }
1166                         break;
1167                 case PT_DETACH:
1168                         /*
1169                          * Reset the process parent.
1170                          *
1171                          * NB: This clears P_TRACED before reparenting
1172                          * a detached process back to its original
1173                          * parent.  Otherwise the debugee will be set
1174                          * as an orphan of the debugger.
1175                          */
1176                         p->p_flag &= ~(P_TRACED | P_WAITED);
1177                         if (p->p_oppid != p->p_pptr->p_pid) {
1178                                 PROC_LOCK(p->p_pptr);
1179                                 sigqueue_take(p->p_ksi);
1180                                 PROC_UNLOCK(p->p_pptr);
1181
1182                                 pp = proc_realparent(p);
1183                                 proc_reparent(p, pp, false);
1184                                 if (pp == initproc)
1185                                         p->p_sigparent = SIGCHLD;
1186                                 CTR3(KTR_PTRACE,
1187                             "PT_DETACH: pid %d reparented to pid %d, sig %d",
1188                                     p->p_pid, pp->p_pid, data);
1189                         } else
1190                                 CTR2(KTR_PTRACE, "PT_DETACH: pid %d, sig %d",
1191                                     p->p_pid, data);
1192                         p->p_ptevents = 0;
1193                         FOREACH_THREAD_IN_PROC(p, td3) {
1194                                 if ((td3->td_dbgflags & TDB_FSTP) != 0) {
1195                                         sigqueue_delete(&td3->td_sigqueue,
1196                                             SIGSTOP);
1197                                 }
1198                                 td3->td_dbgflags &= ~(TDB_XSIG | TDB_FSTP |
1199                                     TDB_SUSPEND);
1200                         }
1201
1202                         if ((p->p_flag2 & P2_PTRACE_FSTP) != 0) {
1203                                 sigqueue_delete(&p->p_sigqueue, SIGSTOP);
1204                                 p->p_flag2 &= ~P2_PTRACE_FSTP;
1205                         }
1206
1207                         /* should we send SIGCHLD? */
1208                         /* childproc_continued(p); */
1209                         break;
1210                 }
1211
1212                 sx_xunlock(&proctree_lock);
1213                 proctree_locked = 0;
1214
1215         sendsig:
1216                 MPASS(proctree_locked == 0);
1217
1218                 /*
1219                  * Clear the pending event for the thread that just
1220                  * reported its event (p_xthread).  This may not be
1221                  * the thread passed to PT_CONTINUE, PT_STEP, etc. if
1222                  * the debugger is resuming a different thread.
1223                  *
1224                  * Deliver any pending signal via the reporting thread.
1225                  */
1226                 MPASS(p->p_xthread != NULL);
1227                 p->p_xthread->td_dbgflags &= ~TDB_XSIG;
1228                 p->p_xthread->td_xsig = data;
1229                 p->p_xthread = NULL;
1230                 p->p_xsig = data;
1231
1232                 /*
1233                  * P_WKILLED is insurance that a PT_KILL/SIGKILL
1234                  * always works immediately, even if another thread is
1235                  * unsuspended first and attempts to handle a
1236                  * different signal or if the POSIX.1b style signal
1237                  * queue cannot accommodate any new signals.
1238                  */
1239                 if (data == SIGKILL)
1240                         proc_wkilled(p);
1241
1242                 /*
1243                  * Unsuspend all threads.  To leave a thread
1244                  * suspended, use PT_SUSPEND to suspend it before
1245                  * continuing the process.
1246                  */
1247                 PROC_SLOCK(p);
1248                 p->p_flag &= ~(P_STOPPED_TRACE | P_STOPPED_SIG | P_WAITED);
1249                 thread_unsuspend(p);
1250                 PROC_SUNLOCK(p);
1251                 break;
1252
1253         case PT_WRITE_I:
1254         case PT_WRITE_D:
1255                 td2->td_dbgflags |= TDB_USERWR;
1256                 PROC_UNLOCK(p);
1257                 error = 0;
1258                 if (proc_writemem(td, p, (off_t)(uintptr_t)addr, &data,
1259                     sizeof(int)) != sizeof(int))
1260                         error = ENOMEM;
1261                 else
1262                         CTR3(KTR_PTRACE, "PT_WRITE: pid %d: %p <= %#x",
1263                             p->p_pid, addr, data);
1264                 PROC_LOCK(p);
1265                 break;
1266
1267         case PT_READ_I:
1268         case PT_READ_D:
1269                 PROC_UNLOCK(p);
1270                 error = tmp = 0;
1271                 if (proc_readmem(td, p, (off_t)(uintptr_t)addr, &tmp,
1272                     sizeof(int)) != sizeof(int))
1273                         error = ENOMEM;
1274                 else
1275                         CTR3(KTR_PTRACE, "PT_READ: pid %d: %p >= %#x",
1276                             p->p_pid, addr, tmp);
1277                 td->td_retval[0] = tmp;
1278                 PROC_LOCK(p);
1279                 break;
1280
1281         case PT_IO:
1282 #ifdef COMPAT_FREEBSD32
1283                 if (wrap32) {
1284                         piod32 = addr;
1285                         iov.iov_base = (void *)(uintptr_t)piod32->piod_addr;
1286                         iov.iov_len = piod32->piod_len;
1287                         uio.uio_offset = (off_t)(uintptr_t)piod32->piod_offs;
1288                         uio.uio_resid = piod32->piod_len;
1289                 } else
1290 #endif
1291                 {
1292                         piod = addr;
1293                         iov.iov_base = piod->piod_addr;
1294                         iov.iov_len = piod->piod_len;
1295                         uio.uio_offset = (off_t)(uintptr_t)piod->piod_offs;
1296                         uio.uio_resid = piod->piod_len;
1297                 }
1298                 uio.uio_iov = &iov;
1299                 uio.uio_iovcnt = 1;
1300                 uio.uio_segflg = UIO_USERSPACE;
1301                 uio.uio_td = td;
1302 #ifdef COMPAT_FREEBSD32
1303                 tmp = wrap32 ? piod32->piod_op : piod->piod_op;
1304 #else
1305                 tmp = piod->piod_op;
1306 #endif
1307                 switch (tmp) {
1308                 case PIOD_READ_D:
1309                 case PIOD_READ_I:
1310                         CTR3(KTR_PTRACE, "PT_IO: pid %d: READ (%p, %#x)",
1311                             p->p_pid, (uintptr_t)uio.uio_offset, uio.uio_resid);
1312                         uio.uio_rw = UIO_READ;
1313                         break;
1314                 case PIOD_WRITE_D:
1315                 case PIOD_WRITE_I:
1316                         CTR3(KTR_PTRACE, "PT_IO: pid %d: WRITE (%p, %#x)",
1317                             p->p_pid, (uintptr_t)uio.uio_offset, uio.uio_resid);
1318                         td2->td_dbgflags |= TDB_USERWR;
1319                         uio.uio_rw = UIO_WRITE;
1320                         break;
1321                 default:
1322                         error = EINVAL;
1323                         goto out;
1324                 }
1325                 PROC_UNLOCK(p);
1326                 error = proc_rwmem(p, &uio);
1327 #ifdef COMPAT_FREEBSD32
1328                 if (wrap32)
1329                         piod32->piod_len -= uio.uio_resid;
1330                 else
1331 #endif
1332                         piod->piod_len -= uio.uio_resid;
1333                 PROC_LOCK(p);
1334                 break;
1335
1336         case PT_KILL:
1337                 CTR1(KTR_PTRACE, "PT_KILL: pid %d", p->p_pid);
1338                 data = SIGKILL;
1339                 goto sendsig;   /* in PT_CONTINUE above */
1340
1341         case PT_SETREGS:
1342                 CTR2(KTR_PTRACE, "PT_SETREGS: tid %d (pid %d)", td2->td_tid,
1343                     p->p_pid);
1344                 td2->td_dbgflags |= TDB_USERWR;
1345                 error = PROC_WRITE(regs, td2, addr);
1346                 break;
1347
1348         case PT_GETREGS:
1349                 CTR2(KTR_PTRACE, "PT_GETREGS: tid %d (pid %d)", td2->td_tid,
1350                     p->p_pid);
1351                 error = PROC_READ(regs, td2, addr);
1352                 break;
1353
1354         case PT_SETFPREGS:
1355                 CTR2(KTR_PTRACE, "PT_SETFPREGS: tid %d (pid %d)", td2->td_tid,
1356                     p->p_pid);
1357                 td2->td_dbgflags |= TDB_USERWR;
1358                 error = PROC_WRITE(fpregs, td2, addr);
1359                 break;
1360
1361         case PT_GETFPREGS:
1362                 CTR2(KTR_PTRACE, "PT_GETFPREGS: tid %d (pid %d)", td2->td_tid,
1363                     p->p_pid);
1364                 error = PROC_READ(fpregs, td2, addr);
1365                 break;
1366
1367         case PT_SETDBREGS:
1368                 CTR2(KTR_PTRACE, "PT_SETDBREGS: tid %d (pid %d)", td2->td_tid,
1369                     p->p_pid);
1370                 td2->td_dbgflags |= TDB_USERWR;
1371                 error = PROC_WRITE(dbregs, td2, addr);
1372                 break;
1373
1374         case PT_GETDBREGS:
1375                 CTR2(KTR_PTRACE, "PT_GETDBREGS: tid %d (pid %d)", td2->td_tid,
1376                     p->p_pid);
1377                 error = PROC_READ(dbregs, td2, addr);
1378                 break;
1379
1380         case PT_LWPINFO:
1381                 if (data <= 0 ||
1382 #ifdef COMPAT_FREEBSD32
1383                     (!wrap32 && data > sizeof(*pl)) ||
1384                     (wrap32 && data > sizeof(*pl32))) {
1385 #else
1386                     data > sizeof(*pl)) {
1387 #endif
1388                         error = EINVAL;
1389                         break;
1390                 }
1391 #ifdef COMPAT_FREEBSD32
1392                 if (wrap32) {
1393                         pl = &r.pl;
1394                         pl32 = addr;
1395                 } else
1396 #endif
1397                 pl = addr;
1398                 bzero(pl, sizeof(*pl));
1399                 pl->pl_lwpid = td2->td_tid;
1400                 pl->pl_event = PL_EVENT_NONE;
1401                 pl->pl_flags = 0;
1402                 if (td2->td_dbgflags & TDB_XSIG) {
1403                         pl->pl_event = PL_EVENT_SIGNAL;
1404                         if (td2->td_si.si_signo != 0 &&
1405 #ifdef COMPAT_FREEBSD32
1406                             ((!wrap32 && data >= offsetof(struct ptrace_lwpinfo,
1407                             pl_siginfo) + sizeof(pl->pl_siginfo)) ||
1408                             (wrap32 && data >= offsetof(struct ptrace_lwpinfo32,
1409                             pl_siginfo) + sizeof(struct siginfo32)))
1410 #else
1411                             data >= offsetof(struct ptrace_lwpinfo, pl_siginfo)
1412                             + sizeof(pl->pl_siginfo)
1413 #endif
1414                         ){
1415                                 pl->pl_flags |= PL_FLAG_SI;
1416                                 pl->pl_siginfo = td2->td_si;
1417                         }
1418                 }
1419                 if (td2->td_dbgflags & TDB_SCE)
1420                         pl->pl_flags |= PL_FLAG_SCE;
1421                 else if (td2->td_dbgflags & TDB_SCX)
1422                         pl->pl_flags |= PL_FLAG_SCX;
1423                 if (td2->td_dbgflags & TDB_EXEC)
1424                         pl->pl_flags |= PL_FLAG_EXEC;
1425                 if (td2->td_dbgflags & TDB_FORK) {
1426                         pl->pl_flags |= PL_FLAG_FORKED;
1427                         pl->pl_child_pid = td2->td_dbg_forked;
1428                         if (td2->td_dbgflags & TDB_VFORK)
1429                                 pl->pl_flags |= PL_FLAG_VFORKED;
1430                 } else if ((td2->td_dbgflags & (TDB_SCX | TDB_VFORK)) ==
1431                     TDB_VFORK)
1432                         pl->pl_flags |= PL_FLAG_VFORK_DONE;
1433                 if (td2->td_dbgflags & TDB_CHILD)
1434                         pl->pl_flags |= PL_FLAG_CHILD;
1435                 if (td2->td_dbgflags & TDB_BORN)
1436                         pl->pl_flags |= PL_FLAG_BORN;
1437                 if (td2->td_dbgflags & TDB_EXIT)
1438                         pl->pl_flags |= PL_FLAG_EXITED;
1439                 pl->pl_sigmask = td2->td_sigmask;
1440                 pl->pl_siglist = td2->td_siglist;
1441                 strcpy(pl->pl_tdname, td2->td_name);
1442                 if ((td2->td_dbgflags & (TDB_SCE | TDB_SCX)) != 0) {
1443                         pl->pl_syscall_code = td2->td_sa.code;
1444                         pl->pl_syscall_narg = td2->td_sa.narg;
1445                 } else {
1446                         pl->pl_syscall_code = 0;
1447                         pl->pl_syscall_narg = 0;
1448                 }
1449 #ifdef COMPAT_FREEBSD32
1450                 if (wrap32)
1451                         ptrace_lwpinfo_to32(pl, pl32);
1452 #endif
1453                 CTR6(KTR_PTRACE,
1454     "PT_LWPINFO: tid %d (pid %d) event %d flags %#x child pid %d syscall %d",
1455                     td2->td_tid, p->p_pid, pl->pl_event, pl->pl_flags,
1456                     pl->pl_child_pid, pl->pl_syscall_code);
1457                 break;
1458
1459         case PT_GETNUMLWPS:
1460                 CTR2(KTR_PTRACE, "PT_GETNUMLWPS: pid %d: %d threads", p->p_pid,
1461                     p->p_numthreads);
1462                 td->td_retval[0] = p->p_numthreads;
1463                 break;
1464
1465         case PT_GETLWPLIST:
1466                 CTR3(KTR_PTRACE, "PT_GETLWPLIST: pid %d: data %d, actual %d",
1467                     p->p_pid, data, p->p_numthreads);
1468                 if (data <= 0) {
1469                         error = EINVAL;
1470                         break;
1471                 }
1472                 num = imin(p->p_numthreads, data);
1473                 PROC_UNLOCK(p);
1474                 buf = malloc(num * sizeof(lwpid_t), M_TEMP, M_WAITOK);
1475                 tmp = 0;
1476                 PROC_LOCK(p);
1477                 FOREACH_THREAD_IN_PROC(p, td2) {
1478                         if (tmp >= num)
1479                                 break;
1480                         buf[tmp++] = td2->td_tid;
1481                 }
1482                 PROC_UNLOCK(p);
1483                 error = copyout(buf, addr, tmp * sizeof(lwpid_t));
1484                 free(buf, M_TEMP);
1485                 if (!error)
1486                         td->td_retval[0] = tmp;
1487                 PROC_LOCK(p);
1488                 break;
1489
1490         case PT_VM_TIMESTAMP:
1491                 CTR2(KTR_PTRACE, "PT_VM_TIMESTAMP: pid %d: timestamp %d",
1492                     p->p_pid, p->p_vmspace->vm_map.timestamp);
1493                 td->td_retval[0] = p->p_vmspace->vm_map.timestamp;
1494                 break;
1495
1496         case PT_VM_ENTRY:
1497                 PROC_UNLOCK(p);
1498 #ifdef COMPAT_FREEBSD32
1499                 if (wrap32)
1500                         error = ptrace_vm_entry32(td, p, addr);
1501                 else
1502 #endif
1503                 error = ptrace_vm_entry(td, p, addr);
1504                 PROC_LOCK(p);
1505                 break;
1506
1507         default:
1508 #ifdef __HAVE_PTRACE_MACHDEP
1509                 if (req >= PT_FIRSTMACH) {
1510                         PROC_UNLOCK(p);
1511                         error = cpu_ptrace(td2, req, addr, data);
1512                         PROC_LOCK(p);
1513                 } else
1514 #endif
1515                         /* Unknown request. */
1516                         error = EINVAL;
1517                 break;
1518         }
1519
1520 out:
1521         /* Drop our hold on this process now that the request has completed. */
1522         _PRELE(p);
1523 fail:
1524         PROC_UNLOCK(p);
1525         if (proctree_locked)
1526                 sx_xunlock(&proctree_lock);
1527         return (error);
1528 }
1529 #undef PROC_READ
1530 #undef PROC_WRITE
1531
1532 /*
1533  * Stop a process because of a debugging event;
1534  * stay stopped until p->p_step is cleared
1535  * (cleared by PIOCCONT in procfs).
1536  */
1537 void
1538 stopevent(struct proc *p, unsigned int event, unsigned int val)
1539 {
1540
1541         PROC_LOCK_ASSERT(p, MA_OWNED);
1542         p->p_step = 1;
1543         CTR3(KTR_PTRACE, "stopevent: pid %d event %u val %u", p->p_pid, event,
1544             val);
1545         do {
1546                 if (event != S_EXIT)
1547                         p->p_xsig = val;
1548                 p->p_xthread = NULL;
1549                 p->p_stype = event;     /* Which event caused the stop? */
1550                 wakeup(&p->p_stype);    /* Wake up any PIOCWAIT'ing procs */
1551                 msleep(&p->p_step, &p->p_mtx, PWAIT, "stopevent", 0);
1552         } while (p->p_step);
1553 }