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