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