sys/kern/sys_process.c

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