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: releng/11.0/sys/kern/sys_process.c 325869 2017-11-15 22:40:15Z gordon $");
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
437 pve->pve_fsid = VNOVAL;
438 pve->pve_fileid = VNOVAL;
439
440 if (error == 0 && obj != NULL) {
441 lobj = obj;
442 for (tobj = obj; tobj != NULL; tobj = tobj->backing_object) {
443 if (tobj != obj)
444 VM_OBJECT_RLOCK(tobj);
445 if (lobj != obj)
446 VM_OBJECT_RUNLOCK(lobj);
447 lobj = tobj;
448 pve->pve_offset += tobj->backing_object_offset;
449 }
450 vp = vm_object_vnode(lobj);
451 if (vp != NULL)
452 vref(vp);
453 if (lobj != obj)
454 VM_OBJECT_RUNLOCK(lobj);
455 VM_OBJECT_RUNLOCK(obj);
456
457 if (vp != NULL) {
458 freepath = NULL;
459 fullpath = NULL;
460 vn_fullpath(td, vp, &fullpath, &freepath);
461 vn_lock(vp, LK_SHARED | LK_RETRY);
462 if (VOP_GETATTR(vp, &vattr, td->td_ucred) == 0) {
463 pve->pve_fileid = vattr.va_fileid;
464 pve->pve_fsid = vattr.va_fsid;
465 }
466 vput(vp);
467
468 if (fullpath != NULL) {
469 pve->pve_pathlen = strlen(fullpath) + 1;
470 if (pve->pve_pathlen <= pathlen) {
471 error = copyout(fullpath, pve->pve_path,
472 pve->pve_pathlen);
473 } else
474 error = ENAMETOOLONG;
475 }
476 if (freepath != NULL)
477 free(freepath, M_TEMP);
478 }
479 }
480 vmspace_free(vm);
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 bzero(pl32, sizeof(*pl32));
522 pl32->pl_lwpid = pl->pl_lwpid;
523 pl32->pl_event = pl->pl_event;
524 pl32->pl_flags = pl->pl_flags;
525 pl32->pl_sigmask = pl->pl_sigmask;
526 pl32->pl_siglist = pl->pl_siglist;
527 siginfo_to_siginfo32(&pl->pl_siginfo, &pl32->pl_siginfo);
528 strcpy(pl32->pl_tdname, pl->pl_tdname);
529 pl32->pl_child_pid = pl->pl_child_pid;
530 pl32->pl_syscall_code = pl->pl_syscall_code;
531 pl32->pl_syscall_narg = pl->pl_syscall_narg;
532 }
533 #endif /* COMPAT_FREEBSD32 */
534
535 /*
536 * Process debugging system call.
537 */
538 #ifndef _SYS_SYSPROTO_H_
539 struct ptrace_args {
540 int req;
541 pid_t pid;
542 caddr_t addr;
543 int data;
544 };
545 #endif
546
547 #ifdef COMPAT_FREEBSD32
548 /*
549 * This CPP subterfuge is to try and reduce the number of ifdefs in
550 * the body of the code.
551 * COPYIN(uap->addr, &r.reg, sizeof r.reg);
552 * becomes either:
553 * copyin(uap->addr, &r.reg, sizeof r.reg);
554 * or
555 * copyin(uap->addr, &r.reg32, sizeof r.reg32);
556 * .. except this is done at runtime.
557 */
558 #define COPYIN(u, k, s) wrap32 ? \
559 copyin(u, k ## 32, s ## 32) : \
560 copyin(u, k, s)
561 #define COPYOUT(k, u, s) wrap32 ? \
562 copyout(k ## 32, u, s ## 32) : \
563 copyout(k, u, s)
564 #else
565 #define COPYIN(u, k, s) copyin(u, k, s)
566 #define COPYOUT(k, u, s) copyout(k, u, s)
567 #endif
568 int
569 sys_ptrace(struct thread *td, struct ptrace_args *uap)
570 {
571 /*
572 * XXX this obfuscation is to reduce stack usage, but the register
573 * structs may be too large to put on the stack anyway.
574 */
575 union {
576 struct ptrace_io_desc piod;
577 struct ptrace_lwpinfo pl;
578 struct ptrace_vm_entry pve;
579 struct dbreg dbreg;
580 struct fpreg fpreg;
581 struct reg reg;
582 #ifdef COMPAT_FREEBSD32
583 struct dbreg32 dbreg32;
584 struct fpreg32 fpreg32;
585 struct reg32 reg32;
586 struct ptrace_io_desc32 piod32;
587 struct ptrace_lwpinfo32 pl32;
588 struct ptrace_vm_entry32 pve32;
589 #endif
590 } r;
591 void *addr;
592 int error = 0;
593 #ifdef COMPAT_FREEBSD32
594 int wrap32 = 0;
595
596 if (SV_CURPROC_FLAG(SV_ILP32))
597 wrap32 = 1;
598 #endif
599 AUDIT_ARG_PID(uap->pid);
600 AUDIT_ARG_CMD(uap->req);
601 AUDIT_ARG_VALUE(uap->data);
602 addr = &r;
603 switch (uap->req) {
604 case PT_GETREGS:
605 case PT_GETFPREGS:
606 case PT_GETDBREGS:
607 case PT_LWPINFO:
608 break;
609 case PT_SETREGS:
610 error = COPYIN(uap->addr, &r.reg, sizeof r.reg);
611 break;
612 case PT_SETFPREGS:
613 error = COPYIN(uap->addr, &r.fpreg, sizeof r.fpreg);
614 break;
615 case PT_SETDBREGS:
616 error = COPYIN(uap->addr, &r.dbreg, sizeof r.dbreg);
617 break;
618 case PT_IO:
619 error = COPYIN(uap->addr, &r.piod, sizeof r.piod);
620 break;
621 case PT_VM_ENTRY:
622 error = COPYIN(uap->addr, &r.pve, sizeof r.pve);
623 break;
624 default:
625 addr = uap->addr;
626 break;
627 }
628 if (error)
629 return (error);
630
631 error = kern_ptrace(td, uap->req, uap->pid, addr, uap->data);
632 if (error)
633 return (error);
634
635 switch (uap->req) {
636 case PT_VM_ENTRY:
637 error = COPYOUT(&r.pve, uap->addr, sizeof r.pve);
638 break;
639 case PT_IO:
640 error = COPYOUT(&r.piod, uap->addr, sizeof r.piod);
641 break;
642 case PT_GETREGS:
643 error = COPYOUT(&r.reg, uap->addr, sizeof r.reg);
644 break;
645 case PT_GETFPREGS:
646 error = COPYOUT(&r.fpreg, uap->addr, sizeof r.fpreg);
647 break;
648 case PT_GETDBREGS:
649 error = COPYOUT(&r.dbreg, uap->addr, sizeof r.dbreg);
650 break;
651 case PT_LWPINFO:
652 error = copyout(&r.pl, uap->addr, uap->data);
653 break;
654 }
655
656 return (error);
657 }
658 #undef COPYIN
659 #undef COPYOUT
660
661 #ifdef COMPAT_FREEBSD32
662 /*
663 * PROC_READ(regs, td2, addr);
664 * becomes either:
665 * proc_read_regs(td2, addr);
666 * or
667 * proc_read_regs32(td2, addr);
668 * .. except this is done at runtime. There is an additional
669 * complication in that PROC_WRITE disallows 32 bit consumers
670 * from writing to 64 bit address space targets.
671 */
672 #define PROC_READ(w, t, a) wrap32 ? \
673 proc_read_ ## w ## 32(t, a) : \
674 proc_read_ ## w (t, a)
675 #define PROC_WRITE(w, t, a) wrap32 ? \
676 (safe ? proc_write_ ## w ## 32(t, a) : EINVAL ) : \
677 proc_write_ ## w (t, a)
678 #else
679 #define PROC_READ(w, t, a) proc_read_ ## w (t, a)
680 #define PROC_WRITE(w, t, a) proc_write_ ## w (t, a)
681 #endif
682
683 int
684 kern_ptrace(struct thread *td, int req, pid_t pid, void *addr, int data)
685 {
686 struct iovec iov;
687 struct uio uio;
688 struct proc *curp, *p, *pp;
689 struct thread *td2 = NULL, *td3;
690 struct ptrace_io_desc *piod = NULL;
691 struct ptrace_lwpinfo *pl;
692 int error, num, tmp;
693 int proctree_locked = 0;
694 lwpid_t tid = 0, *buf;
695 #ifdef COMPAT_FREEBSD32
696 int wrap32 = 0, safe = 0;
697 struct ptrace_io_desc32 *piod32 = NULL;
698 struct ptrace_lwpinfo32 *pl32 = NULL;
699 struct ptrace_lwpinfo plr;
700 #endif
701
702 curp = td->td_proc;
703
704 /* Lock proctree before locking the process. */
705 switch (req) {
706 case PT_TRACE_ME:
707 case PT_ATTACH:
708 case PT_STEP:
709 case PT_CONTINUE:
710 case PT_TO_SCE:
711 case PT_TO_SCX:
712 case PT_SYSCALL:
713 case PT_FOLLOW_FORK:
714 case PT_LWP_EVENTS:
715 case PT_DETACH:
716 sx_xlock(&proctree_lock);
717 proctree_locked = 1;
718 break;
719 default:
720 break;
721 }
722
723 if (req == PT_TRACE_ME) {
724 p = td->td_proc;
725 PROC_LOCK(p);
726 } else {
727 if (pid <= PID_MAX) {
728 if ((p = pfind(pid)) == NULL) {
729 if (proctree_locked)
730 sx_xunlock(&proctree_lock);
731 return (ESRCH);
732 }
733 } else {
734 td2 = tdfind(pid, -1);
735 if (td2 == NULL) {
736 if (proctree_locked)
737 sx_xunlock(&proctree_lock);
738 return (ESRCH);
739 }
740 p = td2->td_proc;
741 tid = pid;
742 pid = p->p_pid;
743 }
744 }
745 AUDIT_ARG_PROCESS(p);
746
747 if ((p->p_flag & P_WEXIT) != 0) {
748 error = ESRCH;
749 goto fail;
750 }
751 if ((error = p_cansee(td, p)) != 0)
752 goto fail;
753
754 if ((error = p_candebug(td, p)) != 0)
755 goto fail;
756
757 /*
758 * System processes can't be debugged.
759 */
760 if ((p->p_flag & P_SYSTEM) != 0) {
761 error = EINVAL;
762 goto fail;
763 }
764
765 if (tid == 0) {
766 if ((p->p_flag & P_STOPPED_TRACE) != 0) {
767 KASSERT(p->p_xthread != NULL, ("NULL p_xthread"));
768 td2 = p->p_xthread;
769 } else {
770 td2 = FIRST_THREAD_IN_PROC(p);
771 }
772 tid = td2->td_tid;
773 }
774
775 #ifdef COMPAT_FREEBSD32
776 /*
777 * Test if we're a 32 bit client and what the target is.
778 * Set the wrap controls accordingly.
779 */
780 if (SV_CURPROC_FLAG(SV_ILP32)) {
781 if (SV_PROC_FLAG(td2->td_proc, SV_ILP32))
782 safe = 1;
783 wrap32 = 1;
784 }
785 #endif
786 /*
787 * Permissions check
788 */
789 switch (req) {
790 case PT_TRACE_ME:
791 /*
792 * Always legal, when there is a parent process which
793 * could trace us. Otherwise, reject.
794 */
795 if ((p->p_flag & P_TRACED) != 0) {
796 error = EBUSY;
797 goto fail;
798 }
799 if (p->p_pptr == initproc) {
800 error = EPERM;
801 goto fail;
802 }
803 break;
804
805 case PT_ATTACH:
806 /* Self */
807 if (p == td->td_proc) {
808 error = EINVAL;
809 goto fail;
810 }
811
812 /* Already traced */
813 if (p->p_flag & P_TRACED) {
814 error = EBUSY;
815 goto fail;
816 }
817
818 /* Can't trace an ancestor if you're being traced. */
819 if (curp->p_flag & P_TRACED) {
820 for (pp = curp->p_pptr; pp != NULL; pp = pp->p_pptr) {
821 if (pp == p) {
822 error = EINVAL;
823 goto fail;
824 }
825 }
826 }
827
828
829 /* OK */
830 break;
831
832 case PT_CLEARSTEP:
833 /* Allow thread to clear single step for itself */
834 if (td->td_tid == tid)
835 break;
836
837 /* FALLTHROUGH */
838 default:
839 /* not being traced... */
840 if ((p->p_flag & P_TRACED) == 0) {
841 error = EPERM;
842 goto fail;
843 }
844
845 /* not being traced by YOU */
846 if (p->p_pptr != td->td_proc) {
847 error = EBUSY;
848 goto fail;
849 }
850
851 /* not currently stopped */
852 if ((p->p_flag & (P_STOPPED_SIG | P_STOPPED_TRACE)) == 0 ||
853 p->p_suspcount != p->p_numthreads ||
854 (p->p_flag & P_WAITED) == 0) {
855 error = EBUSY;
856 goto fail;
857 }
858
859 if ((p->p_flag & P_STOPPED_TRACE) == 0) {
860 static int count = 0;
861 if (count++ == 0)
862 printf("P_STOPPED_TRACE not set.\n");
863 }
864
865 /* OK */
866 break;
867 }
868
869 /* Keep this process around until we finish this request. */
870 _PHOLD(p);
871
872 #ifdef FIX_SSTEP
873 /*
874 * Single step fixup ala procfs
875 */
876 FIX_SSTEP(td2);
877 #endif
878
879 /*
880 * Actually do the requests
881 */
882
883 td->td_retval[0] = 0;
884
885 switch (req) {
886 case PT_TRACE_ME:
887 /* set my trace flag and "owner" so it can read/write me */
888 p->p_flag |= P_TRACED;
889 if (p->p_flag & P_PPWAIT)
890 p->p_flag |= P_PPTRACE;
891 p->p_oppid = p->p_pptr->p_pid;
892 CTR1(KTR_PTRACE, "PT_TRACE_ME: pid %d", p->p_pid);
893 break;
894
895 case PT_ATTACH:
896 /* security check done above */
897 /*
898 * It would be nice if the tracing relationship was separate
899 * from the parent relationship but that would require
900 * another set of links in the proc struct or for "wait"
901 * to scan the entire proc table. To make life easier,
902 * we just re-parent the process we're trying to trace.
903 * The old parent is remembered so we can put things back
904 * on a "detach".
905 */
906 p->p_flag |= P_TRACED;
907 p->p_oppid = p->p_pptr->p_pid;
908 if (p->p_pptr != td->td_proc) {
909 proc_reparent(p, td->td_proc);
910 }
911 data = SIGSTOP;
912 CTR2(KTR_PTRACE, "PT_ATTACH: pid %d, oppid %d", p->p_pid,
913 p->p_oppid);
914 goto sendsig; /* in PT_CONTINUE below */
915
916 case PT_CLEARSTEP:
917 CTR2(KTR_PTRACE, "PT_CLEARSTEP: tid %d (pid %d)", td2->td_tid,
918 p->p_pid);
919 error = ptrace_clear_single_step(td2);
920 break;
921
922 case PT_SETSTEP:
923 CTR2(KTR_PTRACE, "PT_SETSTEP: tid %d (pid %d)", td2->td_tid,
924 p->p_pid);
925 error = ptrace_single_step(td2);
926 break;
927
928 case PT_SUSPEND:
929 CTR2(KTR_PTRACE, "PT_SUSPEND: tid %d (pid %d)", td2->td_tid,
930 p->p_pid);
931 td2->td_dbgflags |= TDB_SUSPEND;
932 thread_lock(td2);
933 td2->td_flags |= TDF_NEEDSUSPCHK;
934 thread_unlock(td2);
935 break;
936
937 case PT_RESUME:
938 CTR2(KTR_PTRACE, "PT_RESUME: tid %d (pid %d)", td2->td_tid,
939 p->p_pid);
940 td2->td_dbgflags &= ~TDB_SUSPEND;
941 break;
942
943 case PT_FOLLOW_FORK:
944 CTR3(KTR_PTRACE, "PT_FOLLOW_FORK: pid %d %s -> %s", p->p_pid,
945 p->p_flag & P_FOLLOWFORK ? "enabled" : "disabled",
946 data ? "enabled" : "disabled");
947 if (data)
948 p->p_flag |= P_FOLLOWFORK;
949 else
950 p->p_flag &= ~P_FOLLOWFORK;
951 break;
952
953 case PT_LWP_EVENTS:
954 CTR3(KTR_PTRACE, "PT_LWP_EVENTS: pid %d %s -> %s", p->p_pid,
955 p->p_flag2 & P2_LWP_EVENTS ? "enabled" : "disabled",
956 data ? "enabled" : "disabled");
957 if (data)
958 p->p_flag2 |= P2_LWP_EVENTS;
959 else
960 p->p_flag2 &= ~P2_LWP_EVENTS;
961 break;
962
963 case PT_STEP:
964 case PT_CONTINUE:
965 case PT_TO_SCE:
966 case PT_TO_SCX:
967 case PT_SYSCALL:
968 case PT_DETACH:
969 /* Zero means do not send any signal */
970 if (data < 0 || data > _SIG_MAXSIG) {
971 error = EINVAL;
972 break;
973 }
974
975 switch (req) {
976 case PT_STEP:
977 CTR2(KTR_PTRACE, "PT_STEP: tid %d (pid %d)",
978 td2->td_tid, p->p_pid);
979 error = ptrace_single_step(td2);
980 if (error)
981 goto out;
982 break;
983 case PT_CONTINUE:
984 case PT_TO_SCE:
985 case PT_TO_SCX:
986 case PT_SYSCALL:
987 if (addr != (void *)1) {
988 error = ptrace_set_pc(td2,
989 (u_long)(uintfptr_t)addr);
990 if (error)
991 goto out;
992 }
993 switch (req) {
994 case PT_TO_SCE:
995 p->p_stops |= S_PT_SCE;
996 CTR4(KTR_PTRACE,
997 "PT_TO_SCE: pid %d, stops = %#x, PC = %#lx, sig = %d",
998 p->p_pid, p->p_stops,
999 (u_long)(uintfptr_t)addr, data);
1000 break;
1001 case PT_TO_SCX:
1002 p->p_stops |= S_PT_SCX;
1003 CTR4(KTR_PTRACE,
1004 "PT_TO_SCX: pid %d, stops = %#x, PC = %#lx, sig = %d",
1005 p->p_pid, p->p_stops,
1006 (u_long)(uintfptr_t)addr, data);
1007 break;
1008 case PT_SYSCALL:
1009 p->p_stops |= S_PT_SCE | S_PT_SCX;
1010 CTR4(KTR_PTRACE,
1011 "PT_SYSCALL: pid %d, stops = %#x, PC = %#lx, sig = %d",
1012 p->p_pid, p->p_stops,
1013 (u_long)(uintfptr_t)addr, data);
1014 break;
1015 case PT_CONTINUE:
1016 CTR3(KTR_PTRACE,
1017 "PT_CONTINUE: pid %d, PC = %#lx, sig = %d",
1018 p->p_pid, (u_long)(uintfptr_t)addr, data);
1019 break;
1020 }
1021 break;
1022 case PT_DETACH:
1023 /*
1024 * Reset the process parent.
1025 *
1026 * NB: This clears P_TRACED before reparenting
1027 * a detached process back to its original
1028 * parent. Otherwise the debugee will be set
1029 * as an orphan of the debugger.
1030 */
1031 p->p_flag &= ~(P_TRACED | P_WAITED | P_FOLLOWFORK);
1032 if (p->p_oppid != p->p_pptr->p_pid) {
1033 PROC_LOCK(p->p_pptr);
1034 sigqueue_take(p->p_ksi);
1035 PROC_UNLOCK(p->p_pptr);
1036
1037 pp = proc_realparent(p);
1038 proc_reparent(p, pp);
1039 if (pp == initproc)
1040 p->p_sigparent = SIGCHLD;
1041 CTR3(KTR_PTRACE,
1042 "PT_DETACH: pid %d reparented to pid %d, sig %d",
1043 p->p_pid, pp->p_pid, data);
1044 } else
1045 CTR2(KTR_PTRACE, "PT_DETACH: pid %d, sig %d",
1046 p->p_pid, data);
1047 p->p_oppid = 0;
1048 p->p_stops = 0;
1049
1050 /* should we send SIGCHLD? */
1051 /* childproc_continued(p); */
1052 break;
1053 }
1054
1055 sendsig:
1056 if (proctree_locked) {
1057 sx_xunlock(&proctree_lock);
1058 proctree_locked = 0;
1059 }
1060 p->p_xsig = data;
1061 p->p_xthread = NULL;
1062 if ((p->p_flag & (P_STOPPED_SIG | P_STOPPED_TRACE)) != 0) {
1063 /* deliver or queue signal */
1064 td2->td_dbgflags &= ~TDB_XSIG;
1065 td2->td_xsig = data;
1066
1067 if (req == PT_DETACH) {
1068 FOREACH_THREAD_IN_PROC(p, td3)
1069 td3->td_dbgflags &= ~TDB_SUSPEND;
1070 }
1071 /*
1072 * unsuspend all threads, to not let a thread run,
1073 * you should use PT_SUSPEND to suspend it before
1074 * continuing process.
1075 */
1076 PROC_SLOCK(p);
1077 p->p_flag &= ~(P_STOPPED_TRACE|P_STOPPED_SIG|P_WAITED);
1078 thread_unsuspend(p);
1079 PROC_SUNLOCK(p);
1080 if (req == PT_ATTACH)
1081 kern_psignal(p, data);
1082 } else {
1083 if (data)
1084 kern_psignal(p, data);
1085 }
1086 break;
1087
1088 case PT_WRITE_I:
1089 case PT_WRITE_D:
1090 td2->td_dbgflags |= TDB_USERWR;
1091 PROC_UNLOCK(p);
1092 error = 0;
1093 if (proc_writemem(td, p, (off_t)(uintptr_t)addr, &data,
1094 sizeof(int)) != sizeof(int))
1095 error = ENOMEM;
1096 else
1097 CTR3(KTR_PTRACE, "PT_WRITE: pid %d: %p <= %#x",
1098 p->p_pid, addr, data);
1099 PROC_LOCK(p);
1100 break;
1101
1102 case PT_READ_I:
1103 case PT_READ_D:
1104 PROC_UNLOCK(p);
1105 error = tmp = 0;
1106 if (proc_readmem(td, p, (off_t)(uintptr_t)addr, &tmp,
1107 sizeof(int)) != sizeof(int))
1108 error = ENOMEM;
1109 else
1110 CTR3(KTR_PTRACE, "PT_READ: pid %d: %p >= %#x",
1111 p->p_pid, addr, tmp);
1112 td->td_retval[0] = tmp;
1113 PROC_LOCK(p);
1114 break;
1115
1116 case PT_IO:
1117 #ifdef COMPAT_FREEBSD32
1118 if (wrap32) {
1119 piod32 = addr;
1120 iov.iov_base = (void *)(uintptr_t)piod32->piod_addr;
1121 iov.iov_len = piod32->piod_len;
1122 uio.uio_offset = (off_t)(uintptr_t)piod32->piod_offs;
1123 uio.uio_resid = piod32->piod_len;
1124 } else
1125 #endif
1126 {
1127 piod = addr;
1128 iov.iov_base = piod->piod_addr;
1129 iov.iov_len = piod->piod_len;
1130 uio.uio_offset = (off_t)(uintptr_t)piod->piod_offs;
1131 uio.uio_resid = piod->piod_len;
1132 }
1133 uio.uio_iov = &iov;
1134 uio.uio_iovcnt = 1;
1135 uio.uio_segflg = UIO_USERSPACE;
1136 uio.uio_td = td;
1137 #ifdef COMPAT_FREEBSD32
1138 tmp = wrap32 ? piod32->piod_op : piod->piod_op;
1139 #else
1140 tmp = piod->piod_op;
1141 #endif
1142 switch (tmp) {
1143 case PIOD_READ_D:
1144 case PIOD_READ_I:
1145 CTR3(KTR_PTRACE, "PT_IO: pid %d: READ (%p, %#x)",
1146 p->p_pid, (uintptr_t)uio.uio_offset, uio.uio_resid);
1147 uio.uio_rw = UIO_READ;
1148 break;
1149 case PIOD_WRITE_D:
1150 case PIOD_WRITE_I:
1151 CTR3(KTR_PTRACE, "PT_IO: pid %d: WRITE (%p, %#x)",
1152 p->p_pid, (uintptr_t)uio.uio_offset, uio.uio_resid);
1153 td2->td_dbgflags |= TDB_USERWR;
1154 uio.uio_rw = UIO_WRITE;
1155 break;
1156 default:
1157 error = EINVAL;
1158 goto out;
1159 }
1160 PROC_UNLOCK(p);
1161 error = proc_rwmem(p, &uio);
1162 #ifdef COMPAT_FREEBSD32
1163 if (wrap32)
1164 piod32->piod_len -= uio.uio_resid;
1165 else
1166 #endif
1167 piod->piod_len -= uio.uio_resid;
1168 PROC_LOCK(p);
1169 break;
1170
1171 case PT_KILL:
1172 CTR1(KTR_PTRACE, "PT_KILL: pid %d", p->p_pid);
1173 data = SIGKILL;
1174 goto sendsig; /* in PT_CONTINUE above */
1175
1176 case PT_SETREGS:
1177 CTR2(KTR_PTRACE, "PT_SETREGS: tid %d (pid %d)", td2->td_tid,
1178 p->p_pid);
1179 td2->td_dbgflags |= TDB_USERWR;
1180 error = PROC_WRITE(regs, td2, addr);
1181 break;
1182
1183 case PT_GETREGS:
1184 CTR2(KTR_PTRACE, "PT_GETREGS: tid %d (pid %d)", td2->td_tid,
1185 p->p_pid);
1186 error = PROC_READ(regs, td2, addr);
1187 break;
1188
1189 case PT_SETFPREGS:
1190 CTR2(KTR_PTRACE, "PT_SETFPREGS: tid %d (pid %d)", td2->td_tid,
1191 p->p_pid);
1192 td2->td_dbgflags |= TDB_USERWR;
1193 error = PROC_WRITE(fpregs, td2, addr);
1194 break;
1195
1196 case PT_GETFPREGS:
1197 CTR2(KTR_PTRACE, "PT_GETFPREGS: tid %d (pid %d)", td2->td_tid,
1198 p->p_pid);
1199 error = PROC_READ(fpregs, td2, addr);
1200 break;
1201
1202 case PT_SETDBREGS:
1203 CTR2(KTR_PTRACE, "PT_SETDBREGS: tid %d (pid %d)", td2->td_tid,
1204 p->p_pid);
1205 td2->td_dbgflags |= TDB_USERWR;
1206 error = PROC_WRITE(dbregs, td2, addr);
1207 break;
1208
1209 case PT_GETDBREGS:
1210 CTR2(KTR_PTRACE, "PT_GETDBREGS: tid %d (pid %d)", td2->td_tid,
1211 p->p_pid);
1212 error = PROC_READ(dbregs, td2, addr);
1213 break;
1214
1215 case PT_LWPINFO:
1216 if (data <= 0 ||
1217 #ifdef COMPAT_FREEBSD32
1218 (!wrap32 && data > sizeof(*pl)) ||
1219 (wrap32 && data > sizeof(*pl32))) {
1220 #else
1221 data > sizeof(*pl)) {
1222 #endif
1223 error = EINVAL;
1224 break;
1225 }
1226 #ifdef COMPAT_FREEBSD32
1227 if (wrap32) {
1228 pl = &plr;
1229 pl32 = addr;
1230 } else
1231 #endif
1232 pl = addr;
1233 bzero(pl, sizeof(*pl));
1234 pl->pl_lwpid = td2->td_tid;
1235 pl->pl_event = PL_EVENT_NONE;
1236 pl->pl_flags = 0;
1237 if (td2->td_dbgflags & TDB_XSIG) {
1238 pl->pl_event = PL_EVENT_SIGNAL;
1239 if (td2->td_dbgksi.ksi_signo != 0 &&
1240 #ifdef COMPAT_FREEBSD32
1241 ((!wrap32 && data >= offsetof(struct ptrace_lwpinfo,
1242 pl_siginfo) + sizeof(pl->pl_siginfo)) ||
1243 (wrap32 && data >= offsetof(struct ptrace_lwpinfo32,
1244 pl_siginfo) + sizeof(struct siginfo32)))
1245 #else
1246 data >= offsetof(struct ptrace_lwpinfo, pl_siginfo)
1247 + sizeof(pl->pl_siginfo)
1248 #endif
1249 ){
1250 pl->pl_flags |= PL_FLAG_SI;
1251 pl->pl_siginfo = td2->td_dbgksi.ksi_info;
1252 }
1253 }
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 }
Cache object: fc1f56580e40b2aa37296ddb37fab6e3
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