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 91 struct ptrace_lwpinfo32 { 92 lwpid_t pl_lwpid; /* LWP described. */ 93 int pl_event; /* Event that stopped the LWP. */ 94 int pl_flags; /* LWP flags. */ 95 sigset_t pl_sigmask; /* LWP signal mask */ 96 sigset_t pl_siglist; /* LWP pending signal */ 97 struct siginfo32 pl_siginfo; /* siginfo for signal */ 98 char pl_tdname[MAXCOMLEN + 1]; /* LWP name. */ 99 pid_t pl_child_pid; /* New child pid */ 100 u_int pl_syscall_code; 101 u_int pl_syscall_narg; 102 }; 103 104 #endif 105 106 /* 107 * Functions implemented using PROC_ACTION(): 108 * 109 * proc_read_regs(proc, regs) 110 * Get the current user-visible register set from the process 111 * and copy it into the regs structure (<machine/reg.h>). 112 * The process is stopped at the time read_regs is called. 113 * 114 * proc_write_regs(proc, regs) 115 * Update the current register set from the passed in regs 116 * structure. Take care to avoid clobbering special CPU 117 * registers or privileged bits in the PSL. 118 * Depending on the architecture this may have fix-up work to do, 119 * especially if the IAR or PCW are modified. 120 * The process is stopped at the time write_regs is called. 121 * 122 * proc_read_fpregs, proc_write_fpregs 123 * deal with the floating point register set, otherwise as above. 124 * 125 * proc_read_dbregs, proc_write_dbregs 126 * deal with the processor debug register set, otherwise as above. 127 * 128 * proc_sstep(proc) 129 * Arrange for the process to trap after executing a single instruction. 130 */ 131 132 #define PROC_ACTION(action) do { \ 133 int error; \ 134 \ 135 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED); \ 136 if ((td->td_proc->p_flag & P_INMEM) == 0) \ 137 error = EIO; \ 138 else \ 139 error = (action); \ 140 return (error); \ 141 } while(0) 142 143 int 144 proc_read_regs(struct thread *td, struct reg *regs) 145 { 146 147 PROC_ACTION(fill_regs(td, regs)); 148 } 149 150 int 151 proc_write_regs(struct thread *td, struct reg *regs) 152 { 153 154 PROC_ACTION(set_regs(td, regs)); 155 } 156 157 int 158 proc_read_dbregs(struct thread *td, struct dbreg *dbregs) 159 { 160 161 PROC_ACTION(fill_dbregs(td, dbregs)); 162 } 163 164 int 165 proc_write_dbregs(struct thread *td, struct dbreg *dbregs) 166 { 167 168 PROC_ACTION(set_dbregs(td, dbregs)); 169 } 170 171 /* 172 * Ptrace doesn't support fpregs at all, and there are no security holes 173 * or translations for fpregs, so we can just copy them. 174 */ 175 int 176 proc_read_fpregs(struct thread *td, struct fpreg *fpregs) 177 { 178 179 PROC_ACTION(fill_fpregs(td, fpregs)); 180 } 181 182 int 183 proc_write_fpregs(struct thread *td, struct fpreg *fpregs) 184 { 185 186 PROC_ACTION(set_fpregs(td, fpregs)); 187 } 188 189 #ifdef COMPAT_FREEBSD32 190 /* For 32 bit binaries, we need to expose the 32 bit regs layouts. */ 191 int 192 proc_read_regs32(struct thread *td, struct reg32 *regs32) 193 { 194 195 PROC_ACTION(fill_regs32(td, regs32)); 196 } 197 198 int 199 proc_write_regs32(struct thread *td, struct reg32 *regs32) 200 { 201 202 PROC_ACTION(set_regs32(td, regs32)); 203 } 204 205 int 206 proc_read_dbregs32(struct thread *td, struct dbreg32 *dbregs32) 207 { 208 209 PROC_ACTION(fill_dbregs32(td, dbregs32)); 210 } 211 212 int 213 proc_write_dbregs32(struct thread *td, struct dbreg32 *dbregs32) 214 { 215 216 PROC_ACTION(set_dbregs32(td, dbregs32)); 217 } 218 219 int 220 proc_read_fpregs32(struct thread *td, struct fpreg32 *fpregs32) 221 { 222 223 PROC_ACTION(fill_fpregs32(td, fpregs32)); 224 } 225 226 int 227 proc_write_fpregs32(struct thread *td, struct fpreg32 *fpregs32) 228 { 229 230 PROC_ACTION(set_fpregs32(td, fpregs32)); 231 } 232 #endif 233 234 int 235 proc_sstep(struct thread *td) 236 { 237 238 PROC_ACTION(ptrace_single_step(td)); 239 } 240 241 int 242 proc_rwmem(struct proc *p, struct uio *uio) 243 { 244 vm_map_t map; 245 vm_offset_t pageno; /* page number */ 246 vm_prot_t reqprot; 247 int error, fault_flags, page_offset, writing; 248 249 /* 250 * Assert that someone has locked this vmspace. (Should be 251 * curthread but we can't assert that.) This keeps the process 252 * from exiting out from under us until this operation completes. 253 */ 254 PROC_ASSERT_HELD(p); 255 PROC_LOCK_ASSERT(p, MA_NOTOWNED); 256 257 /* 258 * The map we want... 259 */ 260 map = &p->p_vmspace->vm_map; 261 262 /* 263 * If we are writing, then we request vm_fault() to create a private 264 * copy of each page. Since these copies will not be writeable by the 265 * process, we must explicity request that they be dirtied. 266 */ 267 writing = uio->uio_rw == UIO_WRITE; 268 reqprot = writing ? VM_PROT_COPY | VM_PROT_READ : VM_PROT_READ; 269 fault_flags = writing ? VM_FAULT_DIRTY : VM_FAULT_NORMAL; 270 271 /* 272 * Only map in one page at a time. We don't have to, but it 273 * makes things easier. This way is trivial - right? 274 */ 275 do { 276 vm_offset_t uva; 277 u_int len; 278 vm_page_t m; 279 280 uva = (vm_offset_t)uio->uio_offset; 281 282 /* 283 * Get the page number of this segment. 284 */ 285 pageno = trunc_page(uva); 286 page_offset = uva - pageno; 287 288 /* 289 * How many bytes to copy 290 */ 291 len = min(PAGE_SIZE - page_offset, uio->uio_resid); 292 293 /* 294 * Fault and hold the page on behalf of the process. 295 */ 296 error = vm_fault_hold(map, pageno, reqprot, fault_flags, &m); 297 if (error != KERN_SUCCESS) { 298 if (error == KERN_RESOURCE_SHORTAGE) 299 error = ENOMEM; 300 else 301 error = EFAULT; 302 break; 303 } 304 305 /* 306 * Now do the i/o move. 307 */ 308 error = uiomove_fromphys(&m, page_offset, len, uio); 309 310 /* Make the I-cache coherent for breakpoints. */ 311 if (writing && error == 0) { 312 vm_map_lock_read(map); 313 if (vm_map_check_protection(map, pageno, pageno + 314 PAGE_SIZE, VM_PROT_EXECUTE)) 315 vm_sync_icache(map, uva, len); 316 vm_map_unlock_read(map); 317 } 318 319 /* 320 * Release the page. 321 */ 322 vm_page_lock(m); 323 vm_page_unhold(m); 324 vm_page_unlock(m); 325 326 } while (error == 0 && uio->uio_resid > 0); 327 328 return (error); 329 } 330 331 static ssize_t 332 proc_iop(struct thread *td, struct proc *p, vm_offset_t va, void *buf, 333 size_t len, enum uio_rw rw) 334 { 335 struct iovec iov; 336 struct uio uio; 337 ssize_t slen; 338 int error; 339 340 MPASS(len < SSIZE_MAX); 341 slen = (ssize_t)len; 342 343 iov.iov_base = (caddr_t)buf; 344 iov.iov_len = len; 345 uio.uio_iov = &iov; 346 uio.uio_iovcnt = 1; 347 uio.uio_offset = va; 348 uio.uio_resid = slen; 349 uio.uio_segflg = UIO_SYSSPACE; 350 uio.uio_rw = rw; 351 uio.uio_td = td; 352 error = proc_rwmem(p, &uio); 353 if (uio.uio_resid == slen) 354 return (-1); 355 return (slen - uio.uio_resid); 356 } 357 358 ssize_t 359 proc_readmem(struct thread *td, struct proc *p, vm_offset_t va, void *buf, 360 size_t len) 361 { 362 363 return (proc_iop(td, p, va, buf, len, UIO_READ)); 364 } 365 366 ssize_t 367 proc_writemem(struct thread *td, struct proc *p, vm_offset_t va, void *buf, 368 size_t len) 369 { 370 371 return (proc_iop(td, p, va, buf, len, UIO_WRITE)); 372 } 373 374 static int 375 ptrace_vm_entry(struct thread *td, struct proc *p, struct ptrace_vm_entry *pve) 376 { 377 struct vattr vattr; 378 vm_map_t map; 379 vm_map_entry_t entry; 380 vm_object_t obj, tobj, lobj; 381 struct vmspace *vm; 382 struct vnode *vp; 383 char *freepath, *fullpath; 384 u_int pathlen; 385 int error, index; 386 387 error = 0; 388 obj = NULL; 389 390 vm = vmspace_acquire_ref(p); 391 map = &vm->vm_map; 392 vm_map_lock_read(map); 393 394 do { 395 entry = map->header.next; 396 index = 0; 397 while (index < pve->pve_entry && entry != &map->header) { 398 entry = entry->next; 399 index++; 400 } 401 if (index != pve->pve_entry) { 402 error = EINVAL; 403 break; 404 } 405 while (entry != &map->header && 406 (entry->eflags & MAP_ENTRY_IS_SUB_MAP) != 0) { 407 entry = entry->next; 408 index++; 409 } 410 if (entry == &map->header) { 411 error = ENOENT; 412 break; 413 } 414 415 /* We got an entry. */ 416 pve->pve_entry = index + 1; 417 pve->pve_timestamp = map->timestamp; 418 pve->pve_start = entry->start; 419 pve->pve_end = entry->end - 1; 420 pve->pve_offset = entry->offset; 421 pve->pve_prot = entry->protection; 422 423 /* Backing object's path needed? */ 424 if (pve->pve_pathlen == 0) 425 break; 426 427 pathlen = pve->pve_pathlen; 428 pve->pve_pathlen = 0; 429 430 obj = entry->object.vm_object; 431 if (obj != NULL) 432 VM_OBJECT_RLOCK(obj); 433 } while (0); 434 435 vm_map_unlock_read(map); 436 vmspace_free(vm); 437 438 pve->pve_fsid = VNOVAL; 439 pve->pve_fileid = VNOVAL; 440 441 if (error == 0 && obj != NULL) { 442 lobj = obj; 443 for (tobj = obj; tobj != NULL; tobj = tobj->backing_object) { 444 if (tobj != obj) 445 VM_OBJECT_RLOCK(tobj); 446 if (lobj != obj) 447 VM_OBJECT_RUNLOCK(lobj); 448 lobj = tobj; 449 pve->pve_offset += tobj->backing_object_offset; 450 } 451 vp = vm_object_vnode(lobj); 452 if (vp != NULL) 453 vref(vp); 454 if (lobj != obj) 455 VM_OBJECT_RUNLOCK(lobj); 456 VM_OBJECT_RUNLOCK(obj); 457 458 if (vp != NULL) { 459 freepath = NULL; 460 fullpath = NULL; 461 vn_fullpath(td, vp, &fullpath, &freepath); 462 vn_lock(vp, LK_SHARED | LK_RETRY); 463 if (VOP_GETATTR(vp, &vattr, td->td_ucred) == 0) { 464 pve->pve_fileid = vattr.va_fileid; 465 pve->pve_fsid = vattr.va_fsid; 466 } 467 vput(vp); 468 469 if (fullpath != NULL) { 470 pve->pve_pathlen = strlen(fullpath) + 1; 471 if (pve->pve_pathlen <= pathlen) { 472 error = copyout(fullpath, pve->pve_path, 473 pve->pve_pathlen); 474 } else 475 error = ENAMETOOLONG; 476 } 477 if (freepath != NULL) 478 free(freepath, M_TEMP); 479 } 480 } 481 if (error == 0) 482 CTR3(KTR_PTRACE, "PT_VM_ENTRY: pid %d, entry %d, start %p", 483 p->p_pid, pve->pve_entry, pve->pve_start); 484 485 return (error); 486 } 487 488 #ifdef COMPAT_FREEBSD32 489 static int 490 ptrace_vm_entry32(struct thread *td, struct proc *p, 491 struct ptrace_vm_entry32 *pve32) 492 { 493 struct ptrace_vm_entry pve; 494 int error; 495 496 pve.pve_entry = pve32->pve_entry; 497 pve.pve_pathlen = pve32->pve_pathlen; 498 pve.pve_path = (void *)(uintptr_t)pve32->pve_path; 499 500 error = ptrace_vm_entry(td, p, &pve); 501 if (error == 0) { 502 pve32->pve_entry = pve.pve_entry; 503 pve32->pve_timestamp = pve.pve_timestamp; 504 pve32->pve_start = pve.pve_start; 505 pve32->pve_end = pve.pve_end; 506 pve32->pve_offset = pve.pve_offset; 507 pve32->pve_prot = pve.pve_prot; 508 pve32->pve_fileid = pve.pve_fileid; 509 pve32->pve_fsid = pve.pve_fsid; 510 } 511 512 pve32->pve_pathlen = pve.pve_pathlen; 513 return (error); 514 } 515 516 static void 517 ptrace_lwpinfo_to32(const struct ptrace_lwpinfo *pl, 518 struct ptrace_lwpinfo32 *pl32) 519 { 520 521 pl32->pl_lwpid = pl->pl_lwpid; 522 pl32->pl_event = pl->pl_event; 523 pl32->pl_flags = pl->pl_flags; 524 pl32->pl_sigmask = pl->pl_sigmask; 525 pl32->pl_siglist = pl->pl_siglist; 526 siginfo_to_siginfo32(&pl->pl_siginfo, &pl32->pl_siginfo); 527 strcpy(pl32->pl_tdname, pl->pl_tdname); 528 pl32->pl_child_pid = pl->pl_child_pid; 529 pl32->pl_syscall_code = pl->pl_syscall_code; 530 pl32->pl_syscall_narg = pl->pl_syscall_narg; 531 } 532 #endif /* COMPAT_FREEBSD32 */ 533 534 /* 535 * Process debugging system call. 536 */ 537 #ifndef _SYS_SYSPROTO_H_ 538 struct ptrace_args { 539 int req; 540 pid_t pid; 541 caddr_t addr; 542 int data; 543 }; 544 #endif 545 546 #ifdef COMPAT_FREEBSD32 547 /* 548 * This CPP subterfuge is to try and reduce the number of ifdefs in 549 * the body of the code. 550 * COPYIN(uap->addr, &r.reg, sizeof r.reg); 551 * becomes either: 552 * copyin(uap->addr, &r.reg, sizeof r.reg); 553 * or 554 * copyin(uap->addr, &r.reg32, sizeof r.reg32); 555 * .. except this is done at runtime. 556 */ 557 #define COPYIN(u, k, s) wrap32 ? \ 558 copyin(u, k ## 32, s ## 32) : \ 559 copyin(u, k, s) 560 #define COPYOUT(k, u, s) wrap32 ? \ 561 copyout(k ## 32, u, s ## 32) : \ 562 copyout(k, u, s) 563 #else 564 #define COPYIN(u, k, s) copyin(u, k, s) 565 #define COPYOUT(k, u, s) copyout(k, u, s) 566 #endif 567 int 568 sys_ptrace(struct thread *td, struct ptrace_args *uap) 569 { 570 /* 571 * XXX this obfuscation is to reduce stack usage, but the register 572 * structs may be too large to put on the stack anyway. 573 */ 574 union { 575 struct ptrace_io_desc piod; 576 struct ptrace_lwpinfo pl; 577 struct ptrace_vm_entry pve; 578 struct dbreg dbreg; 579 struct fpreg fpreg; 580 struct reg reg; 581 #ifdef COMPAT_FREEBSD32 582 struct dbreg32 dbreg32; 583 struct fpreg32 fpreg32; 584 struct reg32 reg32; 585 struct ptrace_io_desc32 piod32; 586 struct ptrace_lwpinfo32 pl32; 587 struct ptrace_vm_entry32 pve32; 588 #endif 589 } r; 590 void *addr; 591 int error = 0; 592 #ifdef COMPAT_FREEBSD32 593 int wrap32 = 0; 594 595 if (SV_CURPROC_FLAG(SV_ILP32)) 596 wrap32 = 1; 597 #endif 598 AUDIT_ARG_PID(uap->pid); 599 AUDIT_ARG_CMD(uap->req); 600 AUDIT_ARG_VALUE(uap->data); 601 addr = &r; 602 switch (uap->req) { 603 case PT_GETREGS: 604 case PT_GETFPREGS: 605 case PT_GETDBREGS: 606 case PT_LWPINFO: 607 break; 608 case PT_SETREGS: 609 error = COPYIN(uap->addr, &r.reg, sizeof r.reg); 610 break; 611 case PT_SETFPREGS: 612 error = COPYIN(uap->addr, &r.fpreg, sizeof r.fpreg); 613 break; 614 case PT_SETDBREGS: 615 error = COPYIN(uap->addr, &r.dbreg, sizeof r.dbreg); 616 break; 617 case PT_IO: 618 error = COPYIN(uap->addr, &r.piod, sizeof r.piod); 619 break; 620 case PT_VM_ENTRY: 621 error = COPYIN(uap->addr, &r.pve, sizeof r.pve); 622 break; 623 default: 624 addr = uap->addr; 625 break; 626 } 627 if (error) 628 return (error); 629 630 error = kern_ptrace(td, uap->req, uap->pid, addr, uap->data); 631 if (error) 632 return (error); 633 634 switch (uap->req) { 635 case PT_VM_ENTRY: 636 error = COPYOUT(&r.pve, uap->addr, sizeof r.pve); 637 break; 638 case PT_IO: 639 error = COPYOUT(&r.piod, uap->addr, sizeof r.piod); 640 break; 641 case PT_GETREGS: 642 error = COPYOUT(&r.reg, uap->addr, sizeof r.reg); 643 break; 644 case PT_GETFPREGS: 645 error = COPYOUT(&r.fpreg, uap->addr, sizeof r.fpreg); 646 break; 647 case PT_GETDBREGS: 648 error = COPYOUT(&r.dbreg, uap->addr, sizeof r.dbreg); 649 break; 650 case PT_LWPINFO: 651 error = copyout(&r.pl, uap->addr, uap->data); 652 break; 653 } 654 655 return (error); 656 } 657 #undef COPYIN 658 #undef COPYOUT 659 660 #ifdef COMPAT_FREEBSD32 661 /* 662 * PROC_READ(regs, td2, addr); 663 * becomes either: 664 * proc_read_regs(td2, addr); 665 * or 666 * proc_read_regs32(td2, addr); 667 * .. except this is done at runtime. There is an additional 668 * complication in that PROC_WRITE disallows 32 bit consumers 669 * from writing to 64 bit address space targets. 670 */ 671 #define PROC_READ(w, t, a) wrap32 ? \ 672 proc_read_ ## w ## 32(t, a) : \ 673 proc_read_ ## w (t, a) 674 #define PROC_WRITE(w, t, a) wrap32 ? \ 675 (safe ? proc_write_ ## w ## 32(t, a) : EINVAL ) : \ 676 proc_write_ ## w (t, a) 677 #else 678 #define PROC_READ(w, t, a) proc_read_ ## w (t, a) 679 #define PROC_WRITE(w, t, a) proc_write_ ## w (t, a) 680 #endif 681 682 int 683 kern_ptrace(struct thread *td, int req, pid_t pid, void *addr, int data) 684 { 685 struct iovec iov; 686 struct uio uio; 687 struct proc *curp, *p, *pp; 688 struct thread *td2 = NULL, *td3; 689 struct ptrace_io_desc *piod = NULL; 690 struct ptrace_lwpinfo *pl; 691 int error, num, tmp; 692 int proctree_locked = 0; 693 lwpid_t tid = 0, *buf; 694 #ifdef COMPAT_FREEBSD32 695 int wrap32 = 0, safe = 0; 696 struct ptrace_io_desc32 *piod32 = NULL; 697 struct ptrace_lwpinfo32 *pl32 = NULL; 698 struct ptrace_lwpinfo plr; 699 #endif 700 701 curp = td->td_proc; 702 703 /* Lock proctree before locking the process. */ 704 switch (req) { 705 case PT_TRACE_ME: 706 case PT_ATTACH: 707 case PT_STEP: 708 case PT_CONTINUE: 709 case PT_TO_SCE: 710 case PT_TO_SCX: 711 case PT_SYSCALL: 712 case PT_FOLLOW_FORK: 713 case PT_LWP_EVENTS: 714 case PT_DETACH: 715 sx_xlock(&proctree_lock); 716 proctree_locked = 1; 717 break; 718 default: 719 break; 720 } 721 722 if (req == PT_TRACE_ME) { 723 p = td->td_proc; 724 PROC_LOCK(p); 725 } else { 726 if (pid <= PID_MAX) { 727 if ((p = pfind(pid)) == NULL) { 728 if (proctree_locked) 729 sx_xunlock(&proctree_lock); 730 return (ESRCH); 731 } 732 } else { 733 td2 = tdfind(pid, -1); 734 if (td2 == NULL) { 735 if (proctree_locked) 736 sx_xunlock(&proctree_lock); 737 return (ESRCH); 738 } 739 p = td2->td_proc; 740 tid = pid; 741 pid = p->p_pid; 742 } 743 } 744 AUDIT_ARG_PROCESS(p); 745 746 if ((p->p_flag & P_WEXIT) != 0) { 747 error = ESRCH; 748 goto fail; 749 } 750 if ((error = p_cansee(td, p)) != 0) 751 goto fail; 752 753 if ((error = p_candebug(td, p)) != 0) 754 goto fail; 755 756 /* 757 * System processes can't be debugged. 758 */ 759 if ((p->p_flag & P_SYSTEM) != 0) { 760 error = EINVAL; 761 goto fail; 762 } 763 764 if (tid == 0) { 765 if ((p->p_flag & P_STOPPED_TRACE) != 0) { 766 KASSERT(p->p_xthread != NULL, ("NULL p_xthread")); 767 td2 = p->p_xthread; 768 } else { 769 td2 = FIRST_THREAD_IN_PROC(p); 770 } 771 tid = td2->td_tid; 772 } 773 774 #ifdef COMPAT_FREEBSD32 775 /* 776 * Test if we're a 32 bit client and what the target is. 777 * Set the wrap controls accordingly. 778 */ 779 if (SV_CURPROC_FLAG(SV_ILP32)) { 780 if (SV_PROC_FLAG(td2->td_proc, SV_ILP32)) 781 safe = 1; 782 wrap32 = 1; 783 } 784 #endif 785 /* 786 * Permissions check 787 */ 788 switch (req) { 789 case PT_TRACE_ME: 790 /* 791 * Always legal, when there is a parent process which 792 * could trace us. Otherwise, reject. 793 */ 794 if ((p->p_flag & P_TRACED) != 0) { 795 error = EBUSY; 796 goto fail; 797 } 798 if (p->p_pptr == initproc) { 799 error = EPERM; 800 goto fail; 801 } 802 break; 803 804 case PT_ATTACH: 805 /* Self */ 806 if (p == td->td_proc) { 807 error = EINVAL; 808 goto fail; 809 } 810 811 /* Already traced */ 812 if (p->p_flag & P_TRACED) { 813 error = EBUSY; 814 goto fail; 815 } 816 817 /* Can't trace an ancestor if you're being traced. */ 818 if (curp->p_flag & P_TRACED) { 819 for (pp = curp->p_pptr; pp != NULL; pp = pp->p_pptr) { 820 if (pp == p) { 821 error = EINVAL; 822 goto fail; 823 } 824 } 825 } 826 827 828 /* OK */ 829 break; 830 831 case PT_CLEARSTEP: 832 /* Allow thread to clear single step for itself */ 833 if (td->td_tid == tid) 834 break; 835 836 /* FALLTHROUGH */ 837 default: 838 /* not being traced... */ 839 if ((p->p_flag & P_TRACED) == 0) { 840 error = EPERM; 841 goto fail; 842 } 843 844 /* not being traced by YOU */ 845 if (p->p_pptr != td->td_proc) { 846 error = EBUSY; 847 goto fail; 848 } 849 850 /* not currently stopped */ 851 if ((p->p_flag & (P_STOPPED_SIG | P_STOPPED_TRACE)) == 0 || 852 p->p_suspcount != p->p_numthreads || 853 (p->p_flag & P_WAITED) == 0) { 854 error = EBUSY; 855 goto fail; 856 } 857 858 if ((p->p_flag & P_STOPPED_TRACE) == 0) { 859 static int count = 0; 860 if (count++ == 0) 861 printf("P_STOPPED_TRACE not set.\n"); 862 } 863 864 /* OK */ 865 break; 866 } 867 868 /* Keep this process around until we finish this request. */ 869 _PHOLD(p); 870 871 #ifdef FIX_SSTEP 872 /* 873 * Single step fixup ala procfs 874 */ 875 FIX_SSTEP(td2); 876 #endif 877 878 /* 879 * Actually do the requests 880 */ 881 882 td->td_retval[0] = 0; 883 884 switch (req) { 885 case PT_TRACE_ME: 886 /* set my trace flag and "owner" so it can read/write me */ 887 p->p_flag |= P_TRACED; 888 if (p->p_flag & P_PPWAIT) 889 p->p_flag |= P_PPTRACE; 890 p->p_oppid = p->p_pptr->p_pid; 891 CTR1(KTR_PTRACE, "PT_TRACE_ME: pid %d", p->p_pid); 892 break; 893 894 case PT_ATTACH: 895 /* security check done above */ 896 /* 897 * It would be nice if the tracing relationship was separate 898 * from the parent relationship but that would require 899 * another set of links in the proc struct or for "wait" 900 * to scan the entire proc table. To make life easier, 901 * we just re-parent the process we're trying to trace. 902 * The old parent is remembered so we can put things back 903 * on a "detach". 904 */ 905 p->p_flag |= P_TRACED; 906 p->p_oppid = p->p_pptr->p_pid; 907 if (p->p_pptr != td->td_proc) { 908 proc_reparent(p, td->td_proc); 909 } 910 data = SIGSTOP; 911 CTR2(KTR_PTRACE, "PT_ATTACH: pid %d, oppid %d", p->p_pid, 912 p->p_oppid); 913 goto sendsig; /* in PT_CONTINUE below */ 914 915 case PT_CLEARSTEP: 916 CTR2(KTR_PTRACE, "PT_CLEARSTEP: tid %d (pid %d)", td2->td_tid, 917 p->p_pid); 918 error = ptrace_clear_single_step(td2); 919 break; 920 921 case PT_SETSTEP: 922 CTR2(KTR_PTRACE, "PT_SETSTEP: tid %d (pid %d)", td2->td_tid, 923 p->p_pid); 924 error = ptrace_single_step(td2); 925 break; 926 927 case PT_SUSPEND: 928 CTR2(KTR_PTRACE, "PT_SUSPEND: tid %d (pid %d)", td2->td_tid, 929 p->p_pid); 930 td2->td_dbgflags |= TDB_SUSPEND; 931 thread_lock(td2); 932 td2->td_flags |= TDF_NEEDSUSPCHK; 933 thread_unlock(td2); 934 break; 935 936 case PT_RESUME: 937 CTR2(KTR_PTRACE, "PT_RESUME: tid %d (pid %d)", td2->td_tid, 938 p->p_pid); 939 td2->td_dbgflags &= ~TDB_SUSPEND; 940 break; 941 942 case PT_FOLLOW_FORK: 943 CTR3(KTR_PTRACE, "PT_FOLLOW_FORK: pid %d %s -> %s", p->p_pid, 944 p->p_flag & P_FOLLOWFORK ? "enabled" : "disabled", 945 data ? "enabled" : "disabled"); 946 if (data) 947 p->p_flag |= P_FOLLOWFORK; 948 else 949 p->p_flag &= ~P_FOLLOWFORK; 950 break; 951 952 case PT_LWP_EVENTS: 953 CTR3(KTR_PTRACE, "PT_LWP_EVENTS: pid %d %s -> %s", p->p_pid, 954 p->p_flag2 & P2_LWP_EVENTS ? "enabled" : "disabled", 955 data ? "enabled" : "disabled"); 956 if (data) 957 p->p_flag2 |= P2_LWP_EVENTS; 958 else 959 p->p_flag2 &= ~P2_LWP_EVENTS; 960 break; 961 962 case PT_STEP: 963 case PT_CONTINUE: 964 case PT_TO_SCE: 965 case PT_TO_SCX: 966 case PT_SYSCALL: 967 case PT_DETACH: 968 /* Zero means do not send any signal */ 969 if (data < 0 || data > _SIG_MAXSIG) { 970 error = EINVAL; 971 break; 972 } 973 974 switch (req) { 975 case PT_STEP: 976 CTR2(KTR_PTRACE, "PT_STEP: tid %d (pid %d)", 977 td2->td_tid, p->p_pid); 978 error = ptrace_single_step(td2); 979 if (error) 980 goto out; 981 break; 982 case PT_CONTINUE: 983 case PT_TO_SCE: 984 case PT_TO_SCX: 985 case PT_SYSCALL: 986 if (addr != (void *)1) { 987 error = ptrace_set_pc(td2, 988 (u_long)(uintfptr_t)addr); 989 if (error) 990 goto out; 991 } 992 switch (req) { 993 case PT_TO_SCE: 994 p->p_stops |= S_PT_SCE; 995 CTR4(KTR_PTRACE, 996 "PT_TO_SCE: pid %d, stops = %#x, PC = %#lx, sig = %d", 997 p->p_pid, p->p_stops, 998 (u_long)(uintfptr_t)addr, data); 999 break; 1000 case PT_TO_SCX: 1001 p->p_stops |= S_PT_SCX; 1002 CTR4(KTR_PTRACE, 1003 "PT_TO_SCX: pid %d, stops = %#x, PC = %#lx, sig = %d", 1004 p->p_pid, p->p_stops, 1005 (u_long)(uintfptr_t)addr, data); 1006 break; 1007 case PT_SYSCALL: 1008 p->p_stops |= S_PT_SCE | S_PT_SCX; 1009 CTR4(KTR_PTRACE, 1010 "PT_SYSCALL: pid %d, stops = %#x, PC = %#lx, sig = %d", 1011 p->p_pid, p->p_stops, 1012 (u_long)(uintfptr_t)addr, data); 1013 break; 1014 case PT_CONTINUE: 1015 CTR3(KTR_PTRACE, 1016 "PT_CONTINUE: pid %d, PC = %#lx, sig = %d", 1017 p->p_pid, (u_long)(uintfptr_t)addr, data); 1018 break; 1019 } 1020 break; 1021 case PT_DETACH: 1022 /* 1023 * Reset the process parent. 1024 * 1025 * NB: This clears P_TRACED before reparenting 1026 * a detached process back to its original 1027 * parent. Otherwise the debugee will be set 1028 * as an orphan of the debugger. 1029 */ 1030 p->p_flag &= ~(P_TRACED | P_WAITED | P_FOLLOWFORK); 1031 if (p->p_oppid != p->p_pptr->p_pid) { 1032 PROC_LOCK(p->p_pptr); 1033 sigqueue_take(p->p_ksi); 1034 PROC_UNLOCK(p->p_pptr); 1035 1036 pp = proc_realparent(p); 1037 proc_reparent(p, pp); 1038 if (pp == initproc) 1039 p->p_sigparent = SIGCHLD; 1040 CTR3(KTR_PTRACE, 1041 "PT_DETACH: pid %d reparented to pid %d, sig %d", 1042 p->p_pid, pp->p_pid, data); 1043 } else 1044 CTR2(KTR_PTRACE, "PT_DETACH: pid %d, sig %d", 1045 p->p_pid, data); 1046 p->p_oppid = 0; 1047 p->p_stops = 0; 1048 1049 /* should we send SIGCHLD? */ 1050 /* childproc_continued(p); */ 1051 break; 1052 } 1053 1054 sendsig: 1055 if (proctree_locked) { 1056 sx_xunlock(&proctree_lock); 1057 proctree_locked = 0; 1058 } 1059 p->p_xsig = data; 1060 p->p_xthread = NULL; 1061 if ((p->p_flag & (P_STOPPED_SIG | P_STOPPED_TRACE)) != 0) { 1062 /* deliver or queue signal */ 1063 td2->td_dbgflags &= ~TDB_XSIG; 1064 td2->td_xsig = data; 1065 1066 if (req == PT_DETACH) { 1067 FOREACH_THREAD_IN_PROC(p, td3) 1068 td3->td_dbgflags &= ~TDB_SUSPEND; 1069 } 1070 /* 1071 * unsuspend all threads, to not let a thread run, 1072 * you should use PT_SUSPEND to suspend it before 1073 * continuing process. 1074 */ 1075 PROC_SLOCK(p); 1076 p->p_flag &= ~(P_STOPPED_TRACE|P_STOPPED_SIG|P_WAITED); 1077 thread_unsuspend(p); 1078 PROC_SUNLOCK(p); 1079 if (req == PT_ATTACH) 1080 kern_psignal(p, data); 1081 } else { 1082 if (data) 1083 kern_psignal(p, data); 1084 } 1085 break; 1086 1087 case PT_WRITE_I: 1088 case PT_WRITE_D: 1089 td2->td_dbgflags |= TDB_USERWR; 1090 PROC_UNLOCK(p); 1091 error = 0; 1092 if (proc_writemem(td, p, (off_t)(uintptr_t)addr, &data, 1093 sizeof(int)) != sizeof(int)) 1094 error = ENOMEM; 1095 else 1096 CTR3(KTR_PTRACE, "PT_WRITE: pid %d: %p <= %#x", 1097 p->p_pid, addr, data); 1098 PROC_LOCK(p); 1099 break; 1100 1101 case PT_READ_I: 1102 case PT_READ_D: 1103 PROC_UNLOCK(p); 1104 error = tmp = 0; 1105 if (proc_readmem(td, p, (off_t)(uintptr_t)addr, &tmp, 1106 sizeof(int)) != sizeof(int)) 1107 error = ENOMEM; 1108 else 1109 CTR3(KTR_PTRACE, "PT_READ: pid %d: %p >= %#x", 1110 p->p_pid, addr, tmp); 1111 td->td_retval[0] = tmp; 1112 PROC_LOCK(p); 1113 break; 1114 1115 case PT_IO: 1116 #ifdef COMPAT_FREEBSD32 1117 if (wrap32) { 1118 piod32 = addr; 1119 iov.iov_base = (void *)(uintptr_t)piod32->piod_addr; 1120 iov.iov_len = piod32->piod_len; 1121 uio.uio_offset = (off_t)(uintptr_t)piod32->piod_offs; 1122 uio.uio_resid = piod32->piod_len; 1123 } else 1124 #endif 1125 { 1126 piod = addr; 1127 iov.iov_base = piod->piod_addr; 1128 iov.iov_len = piod->piod_len; 1129 uio.uio_offset = (off_t)(uintptr_t)piod->piod_offs; 1130 uio.uio_resid = piod->piod_len; 1131 } 1132 uio.uio_iov = &iov; 1133 uio.uio_iovcnt = 1; 1134 uio.uio_segflg = UIO_USERSPACE; 1135 uio.uio_td = td; 1136 #ifdef COMPAT_FREEBSD32 1137 tmp = wrap32 ? piod32->piod_op : piod->piod_op; 1138 #else 1139 tmp = piod->piod_op; 1140 #endif 1141 switch (tmp) { 1142 case PIOD_READ_D: 1143 case PIOD_READ_I: 1144 CTR3(KTR_PTRACE, "PT_IO: pid %d: READ (%p, %#x)", 1145 p->p_pid, (uintptr_t)uio.uio_offset, uio.uio_resid); 1146 uio.uio_rw = UIO_READ; 1147 break; 1148 case PIOD_WRITE_D: 1149 case PIOD_WRITE_I: 1150 CTR3(KTR_PTRACE, "PT_IO: pid %d: WRITE (%p, %#x)", 1151 p->p_pid, (uintptr_t)uio.uio_offset, uio.uio_resid); 1152 td2->td_dbgflags |= TDB_USERWR; 1153 uio.uio_rw = UIO_WRITE; 1154 break; 1155 default: 1156 error = EINVAL; 1157 goto out; 1158 } 1159 PROC_UNLOCK(p); 1160 error = proc_rwmem(p, &uio); 1161 #ifdef COMPAT_FREEBSD32 1162 if (wrap32) 1163 piod32->piod_len -= uio.uio_resid; 1164 else 1165 #endif 1166 piod->piod_len -= uio.uio_resid; 1167 PROC_LOCK(p); 1168 break; 1169 1170 case PT_KILL: 1171 CTR1(KTR_PTRACE, "PT_KILL: pid %d", p->p_pid); 1172 data = SIGKILL; 1173 goto sendsig; /* in PT_CONTINUE above */ 1174 1175 case PT_SETREGS: 1176 CTR2(KTR_PTRACE, "PT_SETREGS: tid %d (pid %d)", td2->td_tid, 1177 p->p_pid); 1178 td2->td_dbgflags |= TDB_USERWR; 1179 error = PROC_WRITE(regs, td2, addr); 1180 break; 1181 1182 case PT_GETREGS: 1183 CTR2(KTR_PTRACE, "PT_GETREGS: tid %d (pid %d)", td2->td_tid, 1184 p->p_pid); 1185 error = PROC_READ(regs, td2, addr); 1186 break; 1187 1188 case PT_SETFPREGS: 1189 CTR2(KTR_PTRACE, "PT_SETFPREGS: tid %d (pid %d)", td2->td_tid, 1190 p->p_pid); 1191 td2->td_dbgflags |= TDB_USERWR; 1192 error = PROC_WRITE(fpregs, td2, addr); 1193 break; 1194 1195 case PT_GETFPREGS: 1196 CTR2(KTR_PTRACE, "PT_GETFPREGS: tid %d (pid %d)", td2->td_tid, 1197 p->p_pid); 1198 error = PROC_READ(fpregs, td2, addr); 1199 break; 1200 1201 case PT_SETDBREGS: 1202 CTR2(KTR_PTRACE, "PT_SETDBREGS: tid %d (pid %d)", td2->td_tid, 1203 p->p_pid); 1204 td2->td_dbgflags |= TDB_USERWR; 1205 error = PROC_WRITE(dbregs, td2, addr); 1206 break; 1207 1208 case PT_GETDBREGS: 1209 CTR2(KTR_PTRACE, "PT_GETDBREGS: tid %d (pid %d)", td2->td_tid, 1210 p->p_pid); 1211 error = PROC_READ(dbregs, td2, addr); 1212 break; 1213 1214 case PT_LWPINFO: 1215 if (data <= 0 || 1216 #ifdef COMPAT_FREEBSD32 1217 (!wrap32 && data > sizeof(*pl)) || 1218 (wrap32 && data > sizeof(*pl32))) { 1219 #else 1220 data > sizeof(*pl)) { 1221 #endif 1222 error = EINVAL; 1223 break; 1224 } 1225 #ifdef COMPAT_FREEBSD32 1226 if (wrap32) { 1227 pl = &plr; 1228 pl32 = addr; 1229 } else 1230 #endif 1231 pl = addr; 1232 pl->pl_lwpid = td2->td_tid; 1233 pl->pl_event = PL_EVENT_NONE; 1234 pl->pl_flags = 0; 1235 if (td2->td_dbgflags & TDB_XSIG) { 1236 pl->pl_event = PL_EVENT_SIGNAL; 1237 if (td2->td_dbgksi.ksi_signo != 0 && 1238 #ifdef COMPAT_FREEBSD32 1239 ((!wrap32 && data >= offsetof(struct ptrace_lwpinfo, 1240 pl_siginfo) + sizeof(pl->pl_siginfo)) || 1241 (wrap32 && data >= offsetof(struct ptrace_lwpinfo32, 1242 pl_siginfo) + sizeof(struct siginfo32))) 1243 #else 1244 data >= offsetof(struct ptrace_lwpinfo, pl_siginfo) 1245 + sizeof(pl->pl_siginfo) 1246 #endif 1247 ){ 1248 pl->pl_flags |= PL_FLAG_SI; 1249 pl->pl_siginfo = td2->td_dbgksi.ksi_info; 1250 } 1251 } 1252 if ((pl->pl_flags & PL_FLAG_SI) == 0) 1253 bzero(&pl->pl_siginfo, sizeof(pl->pl_siginfo)); 1254 if (td2->td_dbgflags & TDB_SCE) 1255 pl->pl_flags |= PL_FLAG_SCE; 1256 else if (td2->td_dbgflags & TDB_SCX) 1257 pl->pl_flags |= PL_FLAG_SCX; 1258 if (td2->td_dbgflags & TDB_EXEC) 1259 pl->pl_flags |= PL_FLAG_EXEC; 1260 if (td2->td_dbgflags & TDB_FORK) { 1261 pl->pl_flags |= PL_FLAG_FORKED; 1262 pl->pl_child_pid = td2->td_dbg_forked; 1263 } 1264 if (td2->td_dbgflags & TDB_CHILD) 1265 pl->pl_flags |= PL_FLAG_CHILD; 1266 if (td2->td_dbgflags & TDB_BORN) 1267 pl->pl_flags |= PL_FLAG_BORN; 1268 if (td2->td_dbgflags & TDB_EXIT) 1269 pl->pl_flags |= PL_FLAG_EXITED; 1270 pl->pl_sigmask = td2->td_sigmask; 1271 pl->pl_siglist = td2->td_siglist; 1272 strcpy(pl->pl_tdname, td2->td_name); 1273 if ((td2->td_dbgflags & (TDB_SCE | TDB_SCX)) != 0) { 1274 pl->pl_syscall_code = td2->td_dbg_sc_code; 1275 pl->pl_syscall_narg = td2->td_dbg_sc_narg; 1276 } else { 1277 pl->pl_syscall_code = 0; 1278 pl->pl_syscall_narg = 0; 1279 } 1280 #ifdef COMPAT_FREEBSD32 1281 if (wrap32) 1282 ptrace_lwpinfo_to32(pl, pl32); 1283 #endif 1284 CTR6(KTR_PTRACE, 1285 "PT_LWPINFO: tid %d (pid %d) event %d flags %#x child pid %d syscall %d", 1286 td2->td_tid, p->p_pid, pl->pl_event, pl->pl_flags, 1287 pl->pl_child_pid, pl->pl_syscall_code); 1288 break; 1289 1290 case PT_GETNUMLWPS: 1291 CTR2(KTR_PTRACE, "PT_GETNUMLWPS: pid %d: %d threads", p->p_pid, 1292 p->p_numthreads); 1293 td->td_retval[0] = p->p_numthreads; 1294 break; 1295 1296 case PT_GETLWPLIST: 1297 CTR3(KTR_PTRACE, "PT_GETLWPLIST: pid %d: data %d, actual %d", 1298 p->p_pid, data, p->p_numthreads); 1299 if (data <= 0) { 1300 error = EINVAL; 1301 break; 1302 } 1303 num = imin(p->p_numthreads, data); 1304 PROC_UNLOCK(p); 1305 buf = malloc(num * sizeof(lwpid_t), M_TEMP, M_WAITOK); 1306 tmp = 0; 1307 PROC_LOCK(p); 1308 FOREACH_THREAD_IN_PROC(p, td2) { 1309 if (tmp >= num) 1310 break; 1311 buf[tmp++] = td2->td_tid; 1312 } 1313 PROC_UNLOCK(p); 1314 error = copyout(buf, addr, tmp * sizeof(lwpid_t)); 1315 free(buf, M_TEMP); 1316 if (!error) 1317 td->td_retval[0] = tmp; 1318 PROC_LOCK(p); 1319 break; 1320 1321 case PT_VM_TIMESTAMP: 1322 CTR2(KTR_PTRACE, "PT_VM_TIMESTAMP: pid %d: timestamp %d", 1323 p->p_pid, p->p_vmspace->vm_map.timestamp); 1324 td->td_retval[0] = p->p_vmspace->vm_map.timestamp; 1325 break; 1326 1327 case PT_VM_ENTRY: 1328 PROC_UNLOCK(p); 1329 #ifdef COMPAT_FREEBSD32 1330 if (wrap32) 1331 error = ptrace_vm_entry32(td, p, addr); 1332 else 1333 #endif 1334 error = ptrace_vm_entry(td, p, addr); 1335 PROC_LOCK(p); 1336 break; 1337 1338 default: 1339 #ifdef __HAVE_PTRACE_MACHDEP 1340 if (req >= PT_FIRSTMACH) { 1341 PROC_UNLOCK(p); 1342 error = cpu_ptrace(td2, req, addr, data); 1343 PROC_LOCK(p); 1344 } else 1345 #endif 1346 /* Unknown request. */ 1347 error = EINVAL; 1348 break; 1349 } 1350 1351 out: 1352 /* Drop our hold on this process now that the request has completed. */ 1353 _PRELE(p); 1354 fail: 1355 PROC_UNLOCK(p); 1356 if (proctree_locked) 1357 sx_xunlock(&proctree_lock); 1358 return (error); 1359 } 1360 #undef PROC_READ 1361 #undef PROC_WRITE 1362 1363 /* 1364 * Stop a process because of a debugging event; 1365 * stay stopped until p->p_step is cleared 1366 * (cleared by PIOCCONT in procfs). 1367 */ 1368 void 1369 stopevent(struct proc *p, unsigned int event, unsigned int val) 1370 { 1371 1372 PROC_LOCK_ASSERT(p, MA_OWNED); 1373 p->p_step = 1; 1374 CTR3(KTR_PTRACE, "stopevent: pid %d event %u val %u", p->p_pid, event, 1375 val); 1376 do { 1377 if (event != S_EXIT) 1378 p->p_xsig = val; 1379 p->p_xthread = NULL; 1380 p->p_stype = event; /* Which event caused the stop? */ 1381 wakeup(&p->p_stype); /* Wake up any PIOCWAIT'ing procs */ 1382 msleep(&p->p_step, &p->p_mtx, PWAIT, "stopevent", 0); 1383 } while (p->p_step); 1384 } 1385