sys_process.c revision 304188
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: stable/11/sys/kern/sys_process.c 304188 2016-08-15 21:10:41Z jhb $");
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
71struct ptrace_io_desc32 {
72	int		piod_op;
73	uint32_t	piod_offs;
74	uint32_t	piod_addr;
75	uint32_t	piod_len;
76};
77
78struct 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
91struct 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
143int
144proc_read_regs(struct thread *td, struct reg *regs)
145{
146
147	PROC_ACTION(fill_regs(td, regs));
148}
149
150int
151proc_write_regs(struct thread *td, struct reg *regs)
152{
153
154	PROC_ACTION(set_regs(td, regs));
155}
156
157int
158proc_read_dbregs(struct thread *td, struct dbreg *dbregs)
159{
160
161	PROC_ACTION(fill_dbregs(td, dbregs));
162}
163
164int
165proc_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 */
175int
176proc_read_fpregs(struct thread *td, struct fpreg *fpregs)
177{
178
179	PROC_ACTION(fill_fpregs(td, fpregs));
180}
181
182int
183proc_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. */
191int
192proc_read_regs32(struct thread *td, struct reg32 *regs32)
193{
194
195	PROC_ACTION(fill_regs32(td, regs32));
196}
197
198int
199proc_write_regs32(struct thread *td, struct reg32 *regs32)
200{
201
202	PROC_ACTION(set_regs32(td, regs32));
203}
204
205int
206proc_read_dbregs32(struct thread *td, struct dbreg32 *dbregs32)
207{
208
209	PROC_ACTION(fill_dbregs32(td, dbregs32));
210}
211
212int
213proc_write_dbregs32(struct thread *td, struct dbreg32 *dbregs32)
214{
215
216	PROC_ACTION(set_dbregs32(td, dbregs32));
217}
218
219int
220proc_read_fpregs32(struct thread *td, struct fpreg32 *fpregs32)
221{
222
223	PROC_ACTION(fill_fpregs32(td, fpregs32));
224}
225
226int
227proc_write_fpregs32(struct thread *td, struct fpreg32 *fpregs32)
228{
229
230	PROC_ACTION(set_fpregs32(td, fpregs32));
231}
232#endif
233
234int
235proc_sstep(struct thread *td)
236{
237
238	PROC_ACTION(ptrace_single_step(td));
239}
240
241int
242proc_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
331static ssize_t
332proc_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
358ssize_t
359proc_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
366ssize_t
367proc_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
374static int
375ptrace_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
489static int
490ptrace_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
516static void
517ptrace_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_
538struct 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
567int
568sys_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		int ptevents;
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_GET_EVENT_MASK:
605	case PT_GETREGS:
606	case PT_GETFPREGS:
607	case PT_GETDBREGS:
608	case PT_LWPINFO:
609		break;
610	case PT_SETREGS:
611		error = COPYIN(uap->addr, &r.reg, sizeof r.reg);
612		break;
613	case PT_SETFPREGS:
614		error = COPYIN(uap->addr, &r.fpreg, sizeof r.fpreg);
615		break;
616	case PT_SETDBREGS:
617		error = COPYIN(uap->addr, &r.dbreg, sizeof r.dbreg);
618		break;
619	case PT_SET_EVENT_MASK:
620		if (uap->data != sizeof(r.ptevents))
621			error = EINVAL;
622		else
623			error = copyin(uap->addr, &r.ptevents, uap->data);
624		break;
625	case PT_IO:
626		error = COPYIN(uap->addr, &r.piod, sizeof r.piod);
627		break;
628	case PT_VM_ENTRY:
629		error = COPYIN(uap->addr, &r.pve, sizeof r.pve);
630		break;
631	default:
632		addr = uap->addr;
633		break;
634	}
635	if (error)
636		return (error);
637
638	error = kern_ptrace(td, uap->req, uap->pid, addr, uap->data);
639	if (error)
640		return (error);
641
642	switch (uap->req) {
643	case PT_VM_ENTRY:
644		error = COPYOUT(&r.pve, uap->addr, sizeof r.pve);
645		break;
646	case PT_IO:
647		error = COPYOUT(&r.piod, uap->addr, sizeof r.piod);
648		break;
649	case PT_GETREGS:
650		error = COPYOUT(&r.reg, uap->addr, sizeof r.reg);
651		break;
652	case PT_GETFPREGS:
653		error = COPYOUT(&r.fpreg, uap->addr, sizeof r.fpreg);
654		break;
655	case PT_GETDBREGS:
656		error = COPYOUT(&r.dbreg, uap->addr, sizeof r.dbreg);
657		break;
658	case PT_GET_EVENT_MASK:
659		/* NB: The size in uap->data is validated in kern_ptrace(). */
660		error = copyout(&r.ptevents, uap->addr, uap->data);
661		break;
662	case PT_LWPINFO:
663		/* NB: The size in uap->data is validated in kern_ptrace(). */
664		error = copyout(&r.pl, uap->addr, uap->data);
665		break;
666	}
667
668	return (error);
669}
670#undef COPYIN
671#undef COPYOUT
672
673#ifdef COMPAT_FREEBSD32
674/*
675 *   PROC_READ(regs, td2, addr);
676 * becomes either:
677 *   proc_read_regs(td2, addr);
678 * or
679 *   proc_read_regs32(td2, addr);
680 * .. except this is done at runtime.  There is an additional
681 * complication in that PROC_WRITE disallows 32 bit consumers
682 * from writing to 64 bit address space targets.
683 */
684#define	PROC_READ(w, t, a)	wrap32 ? \
685	proc_read_ ## w ## 32(t, a) : \
686	proc_read_ ## w (t, a)
687#define	PROC_WRITE(w, t, a)	wrap32 ? \
688	(safe ? proc_write_ ## w ## 32(t, a) : EINVAL ) : \
689	proc_write_ ## w (t, a)
690#else
691#define	PROC_READ(w, t, a)	proc_read_ ## w (t, a)
692#define	PROC_WRITE(w, t, a)	proc_write_ ## w (t, a)
693#endif
694
695int
696kern_ptrace(struct thread *td, int req, pid_t pid, void *addr, int data)
697{
698	struct iovec iov;
699	struct uio uio;
700	struct proc *curp, *p, *pp;
701	struct thread *td2 = NULL, *td3;
702	struct ptrace_io_desc *piod = NULL;
703	struct ptrace_lwpinfo *pl;
704	int error, num, tmp;
705	int proctree_locked = 0;
706	lwpid_t tid = 0, *buf;
707#ifdef COMPAT_FREEBSD32
708	int wrap32 = 0, safe = 0;
709	struct ptrace_io_desc32 *piod32 = NULL;
710	struct ptrace_lwpinfo32 *pl32 = NULL;
711	struct ptrace_lwpinfo plr;
712#endif
713
714	curp = td->td_proc;
715
716	/* Lock proctree before locking the process. */
717	switch (req) {
718	case PT_TRACE_ME:
719	case PT_ATTACH:
720	case PT_STEP:
721	case PT_CONTINUE:
722	case PT_TO_SCE:
723	case PT_TO_SCX:
724	case PT_SYSCALL:
725	case PT_FOLLOW_FORK:
726	case PT_LWP_EVENTS:
727	case PT_GET_EVENT_MASK:
728	case PT_SET_EVENT_MASK:
729	case PT_DETACH:
730		sx_xlock(&proctree_lock);
731		proctree_locked = 1;
732		break;
733	default:
734		break;
735	}
736
737	if (req == PT_TRACE_ME) {
738		p = td->td_proc;
739		PROC_LOCK(p);
740	} else {
741		if (pid <= PID_MAX) {
742			if ((p = pfind(pid)) == NULL) {
743				if (proctree_locked)
744					sx_xunlock(&proctree_lock);
745				return (ESRCH);
746			}
747		} else {
748			td2 = tdfind(pid, -1);
749			if (td2 == NULL) {
750				if (proctree_locked)
751					sx_xunlock(&proctree_lock);
752				return (ESRCH);
753			}
754			p = td2->td_proc;
755			tid = pid;
756			pid = p->p_pid;
757		}
758	}
759	AUDIT_ARG_PROCESS(p);
760
761	if ((p->p_flag & P_WEXIT) != 0) {
762		error = ESRCH;
763		goto fail;
764	}
765	if ((error = p_cansee(td, p)) != 0)
766		goto fail;
767
768	if ((error = p_candebug(td, p)) != 0)
769		goto fail;
770
771	/*
772	 * System processes can't be debugged.
773	 */
774	if ((p->p_flag & P_SYSTEM) != 0) {
775		error = EINVAL;
776		goto fail;
777	}
778
779	if (tid == 0) {
780		if ((p->p_flag & P_STOPPED_TRACE) != 0) {
781			KASSERT(p->p_xthread != NULL, ("NULL p_xthread"));
782			td2 = p->p_xthread;
783		} else {
784			td2 = FIRST_THREAD_IN_PROC(p);
785		}
786		tid = td2->td_tid;
787	}
788
789#ifdef COMPAT_FREEBSD32
790	/*
791	 * Test if we're a 32 bit client and what the target is.
792	 * Set the wrap controls accordingly.
793	 */
794	if (SV_CURPROC_FLAG(SV_ILP32)) {
795		if (SV_PROC_FLAG(td2->td_proc, SV_ILP32))
796			safe = 1;
797		wrap32 = 1;
798	}
799#endif
800	/*
801	 * Permissions check
802	 */
803	switch (req) {
804	case PT_TRACE_ME:
805		/*
806		 * Always legal, when there is a parent process which
807		 * could trace us.  Otherwise, reject.
808		 */
809		if ((p->p_flag & P_TRACED) != 0) {
810			error = EBUSY;
811			goto fail;
812		}
813		if (p->p_pptr == initproc) {
814			error = EPERM;
815			goto fail;
816		}
817		break;
818
819	case PT_ATTACH:
820		/* Self */
821		if (p == td->td_proc) {
822			error = EINVAL;
823			goto fail;
824		}
825
826		/* Already traced */
827		if (p->p_flag & P_TRACED) {
828			error = EBUSY;
829			goto fail;
830		}
831
832		/* Can't trace an ancestor if you're being traced. */
833		if (curp->p_flag & P_TRACED) {
834			for (pp = curp->p_pptr; pp != NULL; pp = pp->p_pptr) {
835				if (pp == p) {
836					error = EINVAL;
837					goto fail;
838				}
839			}
840		}
841
842
843		/* OK */
844		break;
845
846	case PT_CLEARSTEP:
847		/* Allow thread to clear single step for itself */
848		if (td->td_tid == tid)
849			break;
850
851		/* FALLTHROUGH */
852	default:
853		/* not being traced... */
854		if ((p->p_flag & P_TRACED) == 0) {
855			error = EPERM;
856			goto fail;
857		}
858
859		/* not being traced by YOU */
860		if (p->p_pptr != td->td_proc) {
861			error = EBUSY;
862			goto fail;
863		}
864
865		/* not currently stopped */
866		if ((p->p_flag & (P_STOPPED_SIG | P_STOPPED_TRACE)) == 0 ||
867		    p->p_suspcount != p->p_numthreads  ||
868		    (p->p_flag & P_WAITED) == 0) {
869			error = EBUSY;
870			goto fail;
871		}
872
873		if ((p->p_flag & P_STOPPED_TRACE) == 0) {
874			static int count = 0;
875			if (count++ == 0)
876				printf("P_STOPPED_TRACE not set.\n");
877		}
878
879		/* OK */
880		break;
881	}
882
883	/* Keep this process around until we finish this request. */
884	_PHOLD(p);
885
886#ifdef FIX_SSTEP
887	/*
888	 * Single step fixup ala procfs
889	 */
890	FIX_SSTEP(td2);
891#endif
892
893	/*
894	 * Actually do the requests
895	 */
896
897	td->td_retval[0] = 0;
898
899	switch (req) {
900	case PT_TRACE_ME:
901		/* set my trace flag and "owner" so it can read/write me */
902		p->p_flag |= P_TRACED;
903		p->p_ptevents = PTRACE_DEFAULT;
904		if (p->p_flag & P_PPWAIT)
905			p->p_flag |= P_PPTRACE;
906		p->p_oppid = p->p_pptr->p_pid;
907		CTR1(KTR_PTRACE, "PT_TRACE_ME: pid %d", p->p_pid);
908		break;
909
910	case PT_ATTACH:
911		/* security check done above */
912		/*
913		 * It would be nice if the tracing relationship was separate
914		 * from the parent relationship but that would require
915		 * another set of links in the proc struct or for "wait"
916		 * to scan the entire proc table.  To make life easier,
917		 * we just re-parent the process we're trying to trace.
918		 * The old parent is remembered so we can put things back
919		 * on a "detach".
920		 */
921		p->p_flag |= P_TRACED;
922		p->p_ptevents = PTRACE_DEFAULT;
923		p->p_oppid = p->p_pptr->p_pid;
924		if (p->p_pptr != td->td_proc) {
925			proc_reparent(p, td->td_proc);
926		}
927		data = SIGSTOP;
928		CTR2(KTR_PTRACE, "PT_ATTACH: pid %d, oppid %d", p->p_pid,
929		    p->p_oppid);
930		goto sendsig;	/* in PT_CONTINUE below */
931
932	case PT_CLEARSTEP:
933		CTR2(KTR_PTRACE, "PT_CLEARSTEP: tid %d (pid %d)", td2->td_tid,
934		    p->p_pid);
935		error = ptrace_clear_single_step(td2);
936		break;
937
938	case PT_SETSTEP:
939		CTR2(KTR_PTRACE, "PT_SETSTEP: tid %d (pid %d)", td2->td_tid,
940		    p->p_pid);
941		error = ptrace_single_step(td2);
942		break;
943
944	case PT_SUSPEND:
945		CTR2(KTR_PTRACE, "PT_SUSPEND: tid %d (pid %d)", td2->td_tid,
946		    p->p_pid);
947		td2->td_dbgflags |= TDB_SUSPEND;
948		thread_lock(td2);
949		td2->td_flags |= TDF_NEEDSUSPCHK;
950		thread_unlock(td2);
951		break;
952
953	case PT_RESUME:
954		CTR2(KTR_PTRACE, "PT_RESUME: tid %d (pid %d)", td2->td_tid,
955		    p->p_pid);
956		td2->td_dbgflags &= ~TDB_SUSPEND;
957		break;
958
959	case PT_FOLLOW_FORK:
960		CTR3(KTR_PTRACE, "PT_FOLLOW_FORK: pid %d %s -> %s", p->p_pid,
961		    p->p_ptevents & PTRACE_FORK ? "enabled" : "disabled",
962		    data ? "enabled" : "disabled");
963		if (data)
964			p->p_ptevents |= PTRACE_FORK;
965		else
966			p->p_ptevents &= ~PTRACE_FORK;
967		break;
968
969	case PT_LWP_EVENTS:
970		CTR3(KTR_PTRACE, "PT_LWP_EVENTS: pid %d %s -> %s", p->p_pid,
971		    p->p_ptevents & PTRACE_LWP ? "enabled" : "disabled",
972		    data ? "enabled" : "disabled");
973		if (data)
974			p->p_ptevents |= PTRACE_LWP;
975		else
976			p->p_ptevents &= ~PTRACE_LWP;
977		break;
978
979	case PT_GET_EVENT_MASK:
980		if (data != sizeof(p->p_ptevents)) {
981			error = EINVAL;
982			break;
983		}
984		CTR2(KTR_PTRACE, "PT_GET_EVENT_MASK: pid %d mask %#x", p->p_pid,
985		    p->p_ptevents);
986		*(int *)addr = p->p_ptevents;
987		break;
988
989	case PT_SET_EVENT_MASK:
990		if (data != sizeof(p->p_ptevents)) {
991			error = EINVAL;
992			break;
993		}
994		tmp = *(int *)addr;
995		if ((tmp & ~(PTRACE_EXEC | PTRACE_SCE | PTRACE_SCX |
996		    PTRACE_FORK | PTRACE_LWP)) != 0) {
997			error = EINVAL;
998			break;
999		}
1000		CTR3(KTR_PTRACE, "PT_SET_EVENT_MASK: pid %d mask %#x -> %#x",
1001		    p->p_pid, p->p_ptevents, tmp);
1002		p->p_ptevents = tmp;
1003		break;
1004
1005	case PT_STEP:
1006	case PT_CONTINUE:
1007	case PT_TO_SCE:
1008	case PT_TO_SCX:
1009	case PT_SYSCALL:
1010	case PT_DETACH:
1011		/* Zero means do not send any signal */
1012		if (data < 0 || data > _SIG_MAXSIG) {
1013			error = EINVAL;
1014			break;
1015		}
1016
1017		switch (req) {
1018		case PT_STEP:
1019			CTR2(KTR_PTRACE, "PT_STEP: tid %d (pid %d)",
1020			    td2->td_tid, p->p_pid);
1021			error = ptrace_single_step(td2);
1022			if (error)
1023				goto out;
1024			break;
1025		case PT_CONTINUE:
1026		case PT_TO_SCE:
1027		case PT_TO_SCX:
1028		case PT_SYSCALL:
1029			if (addr != (void *)1) {
1030				error = ptrace_set_pc(td2,
1031				    (u_long)(uintfptr_t)addr);
1032				if (error)
1033					goto out;
1034			}
1035			switch (req) {
1036			case PT_TO_SCE:
1037				p->p_ptevents |= PTRACE_SCE;
1038				CTR4(KTR_PTRACE,
1039		    "PT_TO_SCE: pid %d, events = %#x, PC = %#lx, sig = %d",
1040				    p->p_pid, p->p_ptevents,
1041				    (u_long)(uintfptr_t)addr, data);
1042				break;
1043			case PT_TO_SCX:
1044				p->p_ptevents |= PTRACE_SCX;
1045				CTR4(KTR_PTRACE,
1046		    "PT_TO_SCX: pid %d, events = %#x, PC = %#lx, sig = %d",
1047				    p->p_pid, p->p_ptevents,
1048				    (u_long)(uintfptr_t)addr, data);
1049				break;
1050			case PT_SYSCALL:
1051				p->p_ptevents |= PTRACE_SYSCALL;
1052				CTR4(KTR_PTRACE,
1053		    "PT_SYSCALL: pid %d, events = %#x, PC = %#lx, sig = %d",
1054				    p->p_pid, p->p_ptevents,
1055				    (u_long)(uintfptr_t)addr, data);
1056				break;
1057			case PT_CONTINUE:
1058				CTR3(KTR_PTRACE,
1059				    "PT_CONTINUE: pid %d, PC = %#lx, sig = %d",
1060				    p->p_pid, (u_long)(uintfptr_t)addr, data);
1061				break;
1062			}
1063			break;
1064		case PT_DETACH:
1065			/*
1066			 * Reset the process parent.
1067			 *
1068			 * NB: This clears P_TRACED before reparenting
1069			 * a detached process back to its original
1070			 * parent.  Otherwise the debugee will be set
1071			 * as an orphan of the debugger.
1072			 */
1073			p->p_flag &= ~(P_TRACED | P_WAITED);
1074			if (p->p_oppid != p->p_pptr->p_pid) {
1075				PROC_LOCK(p->p_pptr);
1076				sigqueue_take(p->p_ksi);
1077				PROC_UNLOCK(p->p_pptr);
1078
1079				pp = proc_realparent(p);
1080				proc_reparent(p, pp);
1081				if (pp == initproc)
1082					p->p_sigparent = SIGCHLD;
1083				CTR3(KTR_PTRACE,
1084			    "PT_DETACH: pid %d reparented to pid %d, sig %d",
1085				    p->p_pid, pp->p_pid, data);
1086			} else
1087				CTR2(KTR_PTRACE, "PT_DETACH: pid %d, sig %d",
1088				    p->p_pid, data);
1089			p->p_oppid = 0;
1090			p->p_ptevents = 0;
1091
1092			/* should we send SIGCHLD? */
1093			/* childproc_continued(p); */
1094			break;
1095		}
1096
1097	sendsig:
1098		if (proctree_locked) {
1099			sx_xunlock(&proctree_lock);
1100			proctree_locked = 0;
1101		}
1102		p->p_xsig = data;
1103		p->p_xthread = NULL;
1104		if ((p->p_flag & (P_STOPPED_SIG | P_STOPPED_TRACE)) != 0) {
1105			/* deliver or queue signal */
1106			td2->td_dbgflags &= ~TDB_XSIG;
1107			td2->td_xsig = data;
1108
1109			if (req == PT_DETACH) {
1110				FOREACH_THREAD_IN_PROC(p, td3)
1111					td3->td_dbgflags &= ~TDB_SUSPEND;
1112			}
1113			/*
1114			 * unsuspend all threads, to not let a thread run,
1115			 * you should use PT_SUSPEND to suspend it before
1116			 * continuing process.
1117			 */
1118			PROC_SLOCK(p);
1119			p->p_flag &= ~(P_STOPPED_TRACE|P_STOPPED_SIG|P_WAITED);
1120			thread_unsuspend(p);
1121			PROC_SUNLOCK(p);
1122			if (req == PT_ATTACH)
1123				kern_psignal(p, data);
1124		} else {
1125			if (data)
1126				kern_psignal(p, data);
1127		}
1128		break;
1129
1130	case PT_WRITE_I:
1131	case PT_WRITE_D:
1132		td2->td_dbgflags |= TDB_USERWR;
1133		PROC_UNLOCK(p);
1134		error = 0;
1135		if (proc_writemem(td, p, (off_t)(uintptr_t)addr, &data,
1136		    sizeof(int)) != sizeof(int))
1137			error = ENOMEM;
1138		else
1139			CTR3(KTR_PTRACE, "PT_WRITE: pid %d: %p <= %#x",
1140			    p->p_pid, addr, data);
1141		PROC_LOCK(p);
1142		break;
1143
1144	case PT_READ_I:
1145	case PT_READ_D:
1146		PROC_UNLOCK(p);
1147		error = tmp = 0;
1148		if (proc_readmem(td, p, (off_t)(uintptr_t)addr, &tmp,
1149		    sizeof(int)) != sizeof(int))
1150			error = ENOMEM;
1151		else
1152			CTR3(KTR_PTRACE, "PT_READ: pid %d: %p >= %#x",
1153			    p->p_pid, addr, tmp);
1154		td->td_retval[0] = tmp;
1155		PROC_LOCK(p);
1156		break;
1157
1158	case PT_IO:
1159#ifdef COMPAT_FREEBSD32
1160		if (wrap32) {
1161			piod32 = addr;
1162			iov.iov_base = (void *)(uintptr_t)piod32->piod_addr;
1163			iov.iov_len = piod32->piod_len;
1164			uio.uio_offset = (off_t)(uintptr_t)piod32->piod_offs;
1165			uio.uio_resid = piod32->piod_len;
1166		} else
1167#endif
1168		{
1169			piod = addr;
1170			iov.iov_base = piod->piod_addr;
1171			iov.iov_len = piod->piod_len;
1172			uio.uio_offset = (off_t)(uintptr_t)piod->piod_offs;
1173			uio.uio_resid = piod->piod_len;
1174		}
1175		uio.uio_iov = &iov;
1176		uio.uio_iovcnt = 1;
1177		uio.uio_segflg = UIO_USERSPACE;
1178		uio.uio_td = td;
1179#ifdef COMPAT_FREEBSD32
1180		tmp = wrap32 ? piod32->piod_op : piod->piod_op;
1181#else
1182		tmp = piod->piod_op;
1183#endif
1184		switch (tmp) {
1185		case PIOD_READ_D:
1186		case PIOD_READ_I:
1187			CTR3(KTR_PTRACE, "PT_IO: pid %d: READ (%p, %#x)",
1188			    p->p_pid, (uintptr_t)uio.uio_offset, uio.uio_resid);
1189			uio.uio_rw = UIO_READ;
1190			break;
1191		case PIOD_WRITE_D:
1192		case PIOD_WRITE_I:
1193			CTR3(KTR_PTRACE, "PT_IO: pid %d: WRITE (%p, %#x)",
1194			    p->p_pid, (uintptr_t)uio.uio_offset, uio.uio_resid);
1195			td2->td_dbgflags |= TDB_USERWR;
1196			uio.uio_rw = UIO_WRITE;
1197			break;
1198		default:
1199			error = EINVAL;
1200			goto out;
1201		}
1202		PROC_UNLOCK(p);
1203		error = proc_rwmem(p, &uio);
1204#ifdef COMPAT_FREEBSD32
1205		if (wrap32)
1206			piod32->piod_len -= uio.uio_resid;
1207		else
1208#endif
1209			piod->piod_len -= uio.uio_resid;
1210		PROC_LOCK(p);
1211		break;
1212
1213	case PT_KILL:
1214		CTR1(KTR_PTRACE, "PT_KILL: pid %d", p->p_pid);
1215		data = SIGKILL;
1216		goto sendsig;	/* in PT_CONTINUE above */
1217
1218	case PT_SETREGS:
1219		CTR2(KTR_PTRACE, "PT_SETREGS: tid %d (pid %d)", td2->td_tid,
1220		    p->p_pid);
1221		td2->td_dbgflags |= TDB_USERWR;
1222		error = PROC_WRITE(regs, td2, addr);
1223		break;
1224
1225	case PT_GETREGS:
1226		CTR2(KTR_PTRACE, "PT_GETREGS: tid %d (pid %d)", td2->td_tid,
1227		    p->p_pid);
1228		error = PROC_READ(regs, td2, addr);
1229		break;
1230
1231	case PT_SETFPREGS:
1232		CTR2(KTR_PTRACE, "PT_SETFPREGS: tid %d (pid %d)", td2->td_tid,
1233		    p->p_pid);
1234		td2->td_dbgflags |= TDB_USERWR;
1235		error = PROC_WRITE(fpregs, td2, addr);
1236		break;
1237
1238	case PT_GETFPREGS:
1239		CTR2(KTR_PTRACE, "PT_GETFPREGS: tid %d (pid %d)", td2->td_tid,
1240		    p->p_pid);
1241		error = PROC_READ(fpregs, td2, addr);
1242		break;
1243
1244	case PT_SETDBREGS:
1245		CTR2(KTR_PTRACE, "PT_SETDBREGS: tid %d (pid %d)", td2->td_tid,
1246		    p->p_pid);
1247		td2->td_dbgflags |= TDB_USERWR;
1248		error = PROC_WRITE(dbregs, td2, addr);
1249		break;
1250
1251	case PT_GETDBREGS:
1252		CTR2(KTR_PTRACE, "PT_GETDBREGS: tid %d (pid %d)", td2->td_tid,
1253		    p->p_pid);
1254		error = PROC_READ(dbregs, td2, addr);
1255		break;
1256
1257	case PT_LWPINFO:
1258		if (data <= 0 ||
1259#ifdef COMPAT_FREEBSD32
1260		    (!wrap32 && data > sizeof(*pl)) ||
1261		    (wrap32 && data > sizeof(*pl32))) {
1262#else
1263		    data > sizeof(*pl)) {
1264#endif
1265			error = EINVAL;
1266			break;
1267		}
1268#ifdef COMPAT_FREEBSD32
1269		if (wrap32) {
1270			pl = &plr;
1271			pl32 = addr;
1272		} else
1273#endif
1274		pl = addr;
1275		pl->pl_lwpid = td2->td_tid;
1276		pl->pl_event = PL_EVENT_NONE;
1277		pl->pl_flags = 0;
1278		if (td2->td_dbgflags & TDB_XSIG) {
1279			pl->pl_event = PL_EVENT_SIGNAL;
1280			if (td2->td_dbgksi.ksi_signo != 0 &&
1281#ifdef COMPAT_FREEBSD32
1282			    ((!wrap32 && data >= offsetof(struct ptrace_lwpinfo,
1283			    pl_siginfo) + sizeof(pl->pl_siginfo)) ||
1284			    (wrap32 && data >= offsetof(struct ptrace_lwpinfo32,
1285			    pl_siginfo) + sizeof(struct siginfo32)))
1286#else
1287			    data >= offsetof(struct ptrace_lwpinfo, pl_siginfo)
1288			    + sizeof(pl->pl_siginfo)
1289#endif
1290			){
1291				pl->pl_flags |= PL_FLAG_SI;
1292				pl->pl_siginfo = td2->td_dbgksi.ksi_info;
1293			}
1294		}
1295		if ((pl->pl_flags & PL_FLAG_SI) == 0)
1296			bzero(&pl->pl_siginfo, sizeof(pl->pl_siginfo));
1297		if (td2->td_dbgflags & TDB_SCE)
1298			pl->pl_flags |= PL_FLAG_SCE;
1299		else if (td2->td_dbgflags & TDB_SCX)
1300			pl->pl_flags |= PL_FLAG_SCX;
1301		if (td2->td_dbgflags & TDB_EXEC)
1302			pl->pl_flags |= PL_FLAG_EXEC;
1303		if (td2->td_dbgflags & TDB_FORK) {
1304			pl->pl_flags |= PL_FLAG_FORKED;
1305			pl->pl_child_pid = td2->td_dbg_forked;
1306		}
1307		if (td2->td_dbgflags & TDB_CHILD)
1308			pl->pl_flags |= PL_FLAG_CHILD;
1309		if (td2->td_dbgflags & TDB_BORN)
1310			pl->pl_flags |= PL_FLAG_BORN;
1311		if (td2->td_dbgflags & TDB_EXIT)
1312			pl->pl_flags |= PL_FLAG_EXITED;
1313		pl->pl_sigmask = td2->td_sigmask;
1314		pl->pl_siglist = td2->td_siglist;
1315		strcpy(pl->pl_tdname, td2->td_name);
1316		if ((td2->td_dbgflags & (TDB_SCE | TDB_SCX)) != 0) {
1317			pl->pl_syscall_code = td2->td_dbg_sc_code;
1318			pl->pl_syscall_narg = td2->td_dbg_sc_narg;
1319		} else {
1320			pl->pl_syscall_code = 0;
1321			pl->pl_syscall_narg = 0;
1322		}
1323#ifdef COMPAT_FREEBSD32
1324		if (wrap32)
1325			ptrace_lwpinfo_to32(pl, pl32);
1326#endif
1327		CTR6(KTR_PTRACE,
1328    "PT_LWPINFO: tid %d (pid %d) event %d flags %#x child pid %d syscall %d",
1329		    td2->td_tid, p->p_pid, pl->pl_event, pl->pl_flags,
1330		    pl->pl_child_pid, pl->pl_syscall_code);
1331		break;
1332
1333	case PT_GETNUMLWPS:
1334		CTR2(KTR_PTRACE, "PT_GETNUMLWPS: pid %d: %d threads", p->p_pid,
1335		    p->p_numthreads);
1336		td->td_retval[0] = p->p_numthreads;
1337		break;
1338
1339	case PT_GETLWPLIST:
1340		CTR3(KTR_PTRACE, "PT_GETLWPLIST: pid %d: data %d, actual %d",
1341		    p->p_pid, data, p->p_numthreads);
1342		if (data <= 0) {
1343			error = EINVAL;
1344			break;
1345		}
1346		num = imin(p->p_numthreads, data);
1347		PROC_UNLOCK(p);
1348		buf = malloc(num * sizeof(lwpid_t), M_TEMP, M_WAITOK);
1349		tmp = 0;
1350		PROC_LOCK(p);
1351		FOREACH_THREAD_IN_PROC(p, td2) {
1352			if (tmp >= num)
1353				break;
1354			buf[tmp++] = td2->td_tid;
1355		}
1356		PROC_UNLOCK(p);
1357		error = copyout(buf, addr, tmp * sizeof(lwpid_t));
1358		free(buf, M_TEMP);
1359		if (!error)
1360			td->td_retval[0] = tmp;
1361		PROC_LOCK(p);
1362		break;
1363
1364	case PT_VM_TIMESTAMP:
1365		CTR2(KTR_PTRACE, "PT_VM_TIMESTAMP: pid %d: timestamp %d",
1366		    p->p_pid, p->p_vmspace->vm_map.timestamp);
1367		td->td_retval[0] = p->p_vmspace->vm_map.timestamp;
1368		break;
1369
1370	case PT_VM_ENTRY:
1371		PROC_UNLOCK(p);
1372#ifdef COMPAT_FREEBSD32
1373		if (wrap32)
1374			error = ptrace_vm_entry32(td, p, addr);
1375		else
1376#endif
1377		error = ptrace_vm_entry(td, p, addr);
1378		PROC_LOCK(p);
1379		break;
1380
1381	default:
1382#ifdef __HAVE_PTRACE_MACHDEP
1383		if (req >= PT_FIRSTMACH) {
1384			PROC_UNLOCK(p);
1385			error = cpu_ptrace(td2, req, addr, data);
1386			PROC_LOCK(p);
1387		} else
1388#endif
1389			/* Unknown request. */
1390			error = EINVAL;
1391		break;
1392	}
1393
1394out:
1395	/* Drop our hold on this process now that the request has completed. */
1396	_PRELE(p);
1397fail:
1398	PROC_UNLOCK(p);
1399	if (proctree_locked)
1400		sx_xunlock(&proctree_lock);
1401	return (error);
1402}
1403#undef PROC_READ
1404#undef PROC_WRITE
1405
1406/*
1407 * Stop a process because of a debugging event;
1408 * stay stopped until p->p_step is cleared
1409 * (cleared by PIOCCONT in procfs).
1410 */
1411void
1412stopevent(struct proc *p, unsigned int event, unsigned int val)
1413{
1414
1415	PROC_LOCK_ASSERT(p, MA_OWNED);
1416	p->p_step = 1;
1417	CTR3(KTR_PTRACE, "stopevent: pid %d event %u val %u", p->p_pid, event,
1418	    val);
1419	do {
1420		if (event != S_EXIT)
1421			p->p_xsig = val;
1422		p->p_xthread = NULL;
1423		p->p_stype = event;	/* Which event caused the stop? */
1424		wakeup(&p->p_stype);	/* Wake up any PIOCWAIT'ing procs */
1425		msleep(&p->p_step, &p->p_mtx, PWAIT, "stopevent", 0);
1426	} while (p->p_step);
1427}
1428