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 341491 2018-12-04 19:07:10Z markj $");
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#endif
91
92/*
93 * Functions implemented using PROC_ACTION():
94 *
95 * proc_read_regs(proc, regs)
96 *	Get the current user-visible register set from the process
97 *	and copy it into the regs structure (<machine/reg.h>).
98 *	The process is stopped at the time read_regs is called.
99 *
100 * proc_write_regs(proc, regs)
101 *	Update the current register set from the passed in regs
102 *	structure.  Take care to avoid clobbering special CPU
103 *	registers or privileged bits in the PSL.
104 *	Depending on the architecture this may have fix-up work to do,
105 *	especially if the IAR or PCW are modified.
106 *	The process is stopped at the time write_regs is called.
107 *
108 * proc_read_fpregs, proc_write_fpregs
109 *	deal with the floating point register set, otherwise as above.
110 *
111 * proc_read_dbregs, proc_write_dbregs
112 *	deal with the processor debug register set, otherwise as above.
113 *
114 * proc_sstep(proc)
115 *	Arrange for the process to trap after executing a single instruction.
116 */
117
118#define	PROC_ACTION(action) do {					\
119	int error;							\
120									\
121	PROC_LOCK_ASSERT(td->td_proc, MA_OWNED);			\
122	if ((td->td_proc->p_flag & P_INMEM) == 0)			\
123		error = EIO;						\
124	else								\
125		error = (action);					\
126	return (error);							\
127} while(0)
128
129int
130proc_read_regs(struct thread *td, struct reg *regs)
131{
132
133	PROC_ACTION(fill_regs(td, regs));
134}
135
136int
137proc_write_regs(struct thread *td, struct reg *regs)
138{
139
140	PROC_ACTION(set_regs(td, regs));
141}
142
143int
144proc_read_dbregs(struct thread *td, struct dbreg *dbregs)
145{
146
147	PROC_ACTION(fill_dbregs(td, dbregs));
148}
149
150int
151proc_write_dbregs(struct thread *td, struct dbreg *dbregs)
152{
153
154	PROC_ACTION(set_dbregs(td, dbregs));
155}
156
157/*
158 * Ptrace doesn't support fpregs at all, and there are no security holes
159 * or translations for fpregs, so we can just copy them.
160 */
161int
162proc_read_fpregs(struct thread *td, struct fpreg *fpregs)
163{
164
165	PROC_ACTION(fill_fpregs(td, fpregs));
166}
167
168int
169proc_write_fpregs(struct thread *td, struct fpreg *fpregs)
170{
171
172	PROC_ACTION(set_fpregs(td, fpregs));
173}
174
175#ifdef COMPAT_FREEBSD32
176/* For 32 bit binaries, we need to expose the 32 bit regs layouts. */
177int
178proc_read_regs32(struct thread *td, struct reg32 *regs32)
179{
180
181	PROC_ACTION(fill_regs32(td, regs32));
182}
183
184int
185proc_write_regs32(struct thread *td, struct reg32 *regs32)
186{
187
188	PROC_ACTION(set_regs32(td, regs32));
189}
190
191int
192proc_read_dbregs32(struct thread *td, struct dbreg32 *dbregs32)
193{
194
195	PROC_ACTION(fill_dbregs32(td, dbregs32));
196}
197
198int
199proc_write_dbregs32(struct thread *td, struct dbreg32 *dbregs32)
200{
201
202	PROC_ACTION(set_dbregs32(td, dbregs32));
203}
204
205int
206proc_read_fpregs32(struct thread *td, struct fpreg32 *fpregs32)
207{
208
209	PROC_ACTION(fill_fpregs32(td, fpregs32));
210}
211
212int
213proc_write_fpregs32(struct thread *td, struct fpreg32 *fpregs32)
214{
215
216	PROC_ACTION(set_fpregs32(td, fpregs32));
217}
218#endif
219
220int
221proc_sstep(struct thread *td)
222{
223
224	PROC_ACTION(ptrace_single_step(td));
225}
226
227int
228proc_rwmem(struct proc *p, struct uio *uio)
229{
230	vm_map_t map;
231	vm_offset_t pageno;		/* page number */
232	vm_prot_t reqprot;
233	int error, fault_flags, page_offset, writing;
234
235	/*
236	 * Assert that someone has locked this vmspace.  (Should be
237	 * curthread but we can't assert that.)  This keeps the process
238	 * from exiting out from under us until this operation completes.
239	 */
240	PROC_ASSERT_HELD(p);
241	PROC_LOCK_ASSERT(p, MA_NOTOWNED);
242
243	/*
244	 * The map we want...
245	 */
246	map = &p->p_vmspace->vm_map;
247
248	/*
249	 * If we are writing, then we request vm_fault() to create a private
250	 * copy of each page.  Since these copies will not be writeable by the
251	 * process, we must explicity request that they be dirtied.
252	 */
253	writing = uio->uio_rw == UIO_WRITE;
254	reqprot = writing ? VM_PROT_COPY | VM_PROT_READ : VM_PROT_READ;
255	fault_flags = writing ? VM_FAULT_DIRTY : VM_FAULT_NORMAL;
256
257	/*
258	 * Only map in one page at a time.  We don't have to, but it
259	 * makes things easier.  This way is trivial - right?
260	 */
261	do {
262		vm_offset_t uva;
263		u_int len;
264		vm_page_t m;
265
266		uva = (vm_offset_t)uio->uio_offset;
267
268		/*
269		 * Get the page number of this segment.
270		 */
271		pageno = trunc_page(uva);
272		page_offset = uva - pageno;
273
274		/*
275		 * How many bytes to copy
276		 */
277		len = min(PAGE_SIZE - page_offset, uio->uio_resid);
278
279		/*
280		 * Fault and hold the page on behalf of the process.
281		 */
282		error = vm_fault_hold(map, pageno, reqprot, fault_flags, &m);
283		if (error != KERN_SUCCESS) {
284			if (error == KERN_RESOURCE_SHORTAGE)
285				error = ENOMEM;
286			else
287				error = EFAULT;
288			break;
289		}
290
291		/*
292		 * Now do the i/o move.
293		 */
294		error = uiomove_fromphys(&m, page_offset, len, uio);
295
296		/* Make the I-cache coherent for breakpoints. */
297		if (writing && error == 0) {
298			vm_map_lock_read(map);
299			if (vm_map_check_protection(map, pageno, pageno +
300			    PAGE_SIZE, VM_PROT_EXECUTE))
301				vm_sync_icache(map, uva, len);
302			vm_map_unlock_read(map);
303		}
304
305		/*
306		 * Release the page.
307		 */
308		vm_page_lock(m);
309		vm_page_unhold(m);
310		vm_page_unlock(m);
311
312	} while (error == 0 && uio->uio_resid > 0);
313
314	return (error);
315}
316
317static ssize_t
318proc_iop(struct thread *td, struct proc *p, vm_offset_t va, void *buf,
319    size_t len, enum uio_rw rw)
320{
321	struct iovec iov;
322	struct uio uio;
323	ssize_t slen;
324	int error;
325
326	MPASS(len < SSIZE_MAX);
327	slen = (ssize_t)len;
328
329	iov.iov_base = (caddr_t)buf;
330	iov.iov_len = len;
331	uio.uio_iov = &iov;
332	uio.uio_iovcnt = 1;
333	uio.uio_offset = va;
334	uio.uio_resid = slen;
335	uio.uio_segflg = UIO_SYSSPACE;
336	uio.uio_rw = rw;
337	uio.uio_td = td;
338	error = proc_rwmem(p, &uio);
339	if (uio.uio_resid == slen)
340		return (-1);
341	return (slen - uio.uio_resid);
342}
343
344ssize_t
345proc_readmem(struct thread *td, struct proc *p, vm_offset_t va, void *buf,
346    size_t len)
347{
348
349	return (proc_iop(td, p, va, buf, len, UIO_READ));
350}
351
352ssize_t
353proc_writemem(struct thread *td, struct proc *p, vm_offset_t va, void *buf,
354    size_t len)
355{
356
357	return (proc_iop(td, p, va, buf, len, UIO_WRITE));
358}
359
360static int
361ptrace_vm_entry(struct thread *td, struct proc *p, struct ptrace_vm_entry *pve)
362{
363	struct vattr vattr;
364	vm_map_t map;
365	vm_map_entry_t entry;
366	vm_object_t obj, tobj, lobj;
367	struct vmspace *vm;
368	struct vnode *vp;
369	char *freepath, *fullpath;
370	u_int pathlen;
371	int error, index;
372
373	error = 0;
374	obj = NULL;
375
376	vm = vmspace_acquire_ref(p);
377	map = &vm->vm_map;
378	vm_map_lock_read(map);
379
380	do {
381		entry = map->header.next;
382		index = 0;
383		while (index < pve->pve_entry && entry != &map->header) {
384			entry = entry->next;
385			index++;
386		}
387		if (index != pve->pve_entry) {
388			error = EINVAL;
389			break;
390		}
391		while (entry != &map->header &&
392		    (entry->eflags & MAP_ENTRY_IS_SUB_MAP) != 0) {
393			entry = entry->next;
394			index++;
395		}
396		if (entry == &map->header) {
397			error = ENOENT;
398			break;
399		}
400
401		/* We got an entry. */
402		pve->pve_entry = index + 1;
403		pve->pve_timestamp = map->timestamp;
404		pve->pve_start = entry->start;
405		pve->pve_end = entry->end - 1;
406		pve->pve_offset = entry->offset;
407		pve->pve_prot = entry->protection;
408
409		/* Backing object's path needed? */
410		if (pve->pve_pathlen == 0)
411			break;
412
413		pathlen = pve->pve_pathlen;
414		pve->pve_pathlen = 0;
415
416		obj = entry->object.vm_object;
417		if (obj != NULL)
418			VM_OBJECT_RLOCK(obj);
419	} while (0);
420
421	vm_map_unlock_read(map);
422
423	pve->pve_fsid = VNOVAL;
424	pve->pve_fileid = VNOVAL;
425
426	if (error == 0 && obj != NULL) {
427		lobj = obj;
428		for (tobj = obj; tobj != NULL; tobj = tobj->backing_object) {
429			if (tobj != obj)
430				VM_OBJECT_RLOCK(tobj);
431			if (lobj != obj)
432				VM_OBJECT_RUNLOCK(lobj);
433			lobj = tobj;
434			pve->pve_offset += tobj->backing_object_offset;
435		}
436		vp = vm_object_vnode(lobj);
437		if (vp != NULL)
438			vref(vp);
439		if (lobj != obj)
440			VM_OBJECT_RUNLOCK(lobj);
441		VM_OBJECT_RUNLOCK(obj);
442
443		if (vp != NULL) {
444			freepath = NULL;
445			fullpath = NULL;
446			vn_fullpath(td, vp, &fullpath, &freepath);
447			vn_lock(vp, LK_SHARED | LK_RETRY);
448			if (VOP_GETATTR(vp, &vattr, td->td_ucred) == 0) {
449				pve->pve_fileid = vattr.va_fileid;
450				pve->pve_fsid = vattr.va_fsid;
451			}
452			vput(vp);
453
454			if (fullpath != NULL) {
455				pve->pve_pathlen = strlen(fullpath) + 1;
456				if (pve->pve_pathlen <= pathlen) {
457					error = copyout(fullpath, pve->pve_path,
458					    pve->pve_pathlen);
459				} else
460					error = ENAMETOOLONG;
461			}
462			if (freepath != NULL)
463				free(freepath, M_TEMP);
464		}
465	}
466	vmspace_free(vm);
467	if (error == 0)
468		CTR3(KTR_PTRACE, "PT_VM_ENTRY: pid %d, entry %d, start %p",
469		    p->p_pid, pve->pve_entry, pve->pve_start);
470
471	return (error);
472}
473
474#ifdef COMPAT_FREEBSD32
475static int
476ptrace_vm_entry32(struct thread *td, struct proc *p,
477    struct ptrace_vm_entry32 *pve32)
478{
479	struct ptrace_vm_entry pve;
480	int error;
481
482	pve.pve_entry = pve32->pve_entry;
483	pve.pve_pathlen = pve32->pve_pathlen;
484	pve.pve_path = (void *)(uintptr_t)pve32->pve_path;
485
486	error = ptrace_vm_entry(td, p, &pve);
487	if (error == 0) {
488		pve32->pve_entry = pve.pve_entry;
489		pve32->pve_timestamp = pve.pve_timestamp;
490		pve32->pve_start = pve.pve_start;
491		pve32->pve_end = pve.pve_end;
492		pve32->pve_offset = pve.pve_offset;
493		pve32->pve_prot = pve.pve_prot;
494		pve32->pve_fileid = pve.pve_fileid;
495		pve32->pve_fsid = pve.pve_fsid;
496	}
497
498	pve32->pve_pathlen = pve.pve_pathlen;
499	return (error);
500}
501
502static void
503ptrace_lwpinfo_to32(const struct ptrace_lwpinfo *pl,
504    struct ptrace_lwpinfo32 *pl32)
505{
506
507	bzero(pl32, sizeof(*pl32));
508	pl32->pl_lwpid = pl->pl_lwpid;
509	pl32->pl_event = pl->pl_event;
510	pl32->pl_flags = pl->pl_flags;
511	pl32->pl_sigmask = pl->pl_sigmask;
512	pl32->pl_siglist = pl->pl_siglist;
513	siginfo_to_siginfo32(&pl->pl_siginfo, &pl32->pl_siginfo);
514	strcpy(pl32->pl_tdname, pl->pl_tdname);
515	pl32->pl_child_pid = pl->pl_child_pid;
516	pl32->pl_syscall_code = pl->pl_syscall_code;
517	pl32->pl_syscall_narg = pl->pl_syscall_narg;
518}
519#endif /* COMPAT_FREEBSD32 */
520
521/*
522 * Process debugging system call.
523 */
524#ifndef _SYS_SYSPROTO_H_
525struct ptrace_args {
526	int	req;
527	pid_t	pid;
528	caddr_t	addr;
529	int	data;
530};
531#endif
532
533#ifdef COMPAT_FREEBSD32
534/*
535 * This CPP subterfuge is to try and reduce the number of ifdefs in
536 * the body of the code.
537 *   COPYIN(uap->addr, &r.reg, sizeof r.reg);
538 * becomes either:
539 *   copyin(uap->addr, &r.reg, sizeof r.reg);
540 * or
541 *   copyin(uap->addr, &r.reg32, sizeof r.reg32);
542 * .. except this is done at runtime.
543 */
544#define	BZERO(a, s)		wrap32 ? \
545	bzero(a ## 32, s ## 32) : \
546	bzero(a, s)
547#define	COPYIN(u, k, s)		wrap32 ? \
548	copyin(u, k ## 32, s ## 32) : \
549	copyin(u, k, s)
550#define	COPYOUT(k, u, s)	wrap32 ? \
551	copyout(k ## 32, u, s ## 32) : \
552	copyout(k, u, s)
553#else
554#define	BZERO(a, s)		bzero(a, s)
555#define	COPYIN(u, k, s)		copyin(u, k, s)
556#define	COPYOUT(k, u, s)	copyout(k, u, s)
557#endif
558int
559sys_ptrace(struct thread *td, struct ptrace_args *uap)
560{
561	/*
562	 * XXX this obfuscation is to reduce stack usage, but the register
563	 * structs may be too large to put on the stack anyway.
564	 */
565	union {
566		struct ptrace_io_desc piod;
567		struct ptrace_lwpinfo pl;
568		struct ptrace_vm_entry pve;
569		struct dbreg dbreg;
570		struct fpreg fpreg;
571		struct reg reg;
572#ifdef COMPAT_FREEBSD32
573		struct dbreg32 dbreg32;
574		struct fpreg32 fpreg32;
575		struct reg32 reg32;
576		struct ptrace_io_desc32 piod32;
577		struct ptrace_lwpinfo32 pl32;
578		struct ptrace_vm_entry32 pve32;
579#endif
580		char args[sizeof(td->td_sa.args)];
581		int ptevents;
582	} r;
583	void *addr;
584	int error = 0;
585#ifdef COMPAT_FREEBSD32
586	int wrap32 = 0;
587
588	if (SV_CURPROC_FLAG(SV_ILP32))
589		wrap32 = 1;
590#endif
591	AUDIT_ARG_PID(uap->pid);
592	AUDIT_ARG_CMD(uap->req);
593	AUDIT_ARG_VALUE(uap->data);
594	addr = &r;
595	switch (uap->req) {
596	case PT_GET_EVENT_MASK:
597	case PT_LWPINFO:
598	case PT_GET_SC_ARGS:
599		break;
600	case PT_GETREGS:
601		BZERO(&r.reg, sizeof r.reg);
602		break;
603	case PT_GETFPREGS:
604		BZERO(&r.fpreg, sizeof r.fpreg);
605		break;
606	case PT_GETDBREGS:
607		BZERO(&r.dbreg, sizeof r.dbreg);
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_SET_EVENT_MASK:
619		if (uap->data != sizeof(r.ptevents))
620			error = EINVAL;
621		else
622			error = copyin(uap->addr, &r.ptevents, uap->data);
623		break;
624	case PT_IO:
625		error = COPYIN(uap->addr, &r.piod, sizeof r.piod);
626		break;
627	case PT_VM_ENTRY:
628		error = COPYIN(uap->addr, &r.pve, sizeof r.pve);
629		break;
630	default:
631		addr = uap->addr;
632		break;
633	}
634	if (error)
635		return (error);
636
637	error = kern_ptrace(td, uap->req, uap->pid, addr, uap->data);
638	if (error)
639		return (error);
640
641	switch (uap->req) {
642	case PT_VM_ENTRY:
643		error = COPYOUT(&r.pve, uap->addr, sizeof r.pve);
644		break;
645	case PT_IO:
646		error = COPYOUT(&r.piod, uap->addr, sizeof r.piod);
647		break;
648	case PT_GETREGS:
649		error = COPYOUT(&r.reg, uap->addr, sizeof r.reg);
650		break;
651	case PT_GETFPREGS:
652		error = COPYOUT(&r.fpreg, uap->addr, sizeof r.fpreg);
653		break;
654	case PT_GETDBREGS:
655		error = COPYOUT(&r.dbreg, uap->addr, sizeof r.dbreg);
656		break;
657	case PT_GET_EVENT_MASK:
658		/* NB: The size in uap->data is validated in kern_ptrace(). */
659		error = copyout(&r.ptevents, uap->addr, uap->data);
660		break;
661	case PT_LWPINFO:
662		/* NB: The size in uap->data is validated in kern_ptrace(). */
663		error = copyout(&r.pl, uap->addr, uap->data);
664		break;
665	case PT_GET_SC_ARGS:
666		error = copyout(r.args, uap->addr, MIN(uap->data,
667		    sizeof(r.args)));
668		break;
669	}
670
671	return (error);
672}
673#undef COPYIN
674#undef COPYOUT
675#undef BZERO
676
677#ifdef COMPAT_FREEBSD32
678/*
679 *   PROC_READ(regs, td2, addr);
680 * becomes either:
681 *   proc_read_regs(td2, addr);
682 * or
683 *   proc_read_regs32(td2, addr);
684 * .. except this is done at runtime.  There is an additional
685 * complication in that PROC_WRITE disallows 32 bit consumers
686 * from writing to 64 bit address space targets.
687 */
688#define	PROC_READ(w, t, a)	wrap32 ? \
689	proc_read_ ## w ## 32(t, a) : \
690	proc_read_ ## w (t, a)
691#define	PROC_WRITE(w, t, a)	wrap32 ? \
692	(safe ? proc_write_ ## w ## 32(t, a) : EINVAL ) : \
693	proc_write_ ## w (t, a)
694#else
695#define	PROC_READ(w, t, a)	proc_read_ ## w (t, a)
696#define	PROC_WRITE(w, t, a)	proc_write_ ## w (t, a)
697#endif
698
699void
700proc_set_traced(struct proc *p, bool stop)
701{
702
703	sx_assert(&proctree_lock, SX_XLOCKED);
704	PROC_LOCK_ASSERT(p, MA_OWNED);
705	p->p_flag |= P_TRACED;
706	if (stop)
707		p->p_flag2 |= P2_PTRACE_FSTP;
708	p->p_ptevents = PTRACE_DEFAULT;
709	p->p_oppid = p->p_pptr->p_pid;
710}
711
712int
713kern_ptrace(struct thread *td, int req, pid_t pid, void *addr, int data)
714{
715	struct iovec iov;
716	struct uio uio;
717	struct proc *curp, *p, *pp;
718	struct thread *td2 = NULL, *td3;
719	struct ptrace_io_desc *piod = NULL;
720	struct ptrace_lwpinfo *pl;
721	int error, num, tmp;
722	int proctree_locked = 0;
723	lwpid_t tid = 0, *buf;
724#ifdef COMPAT_FREEBSD32
725	int wrap32 = 0, safe = 0;
726	struct ptrace_io_desc32 *piod32 = NULL;
727	struct ptrace_lwpinfo32 *pl32 = NULL;
728	struct ptrace_lwpinfo plr;
729#endif
730
731	curp = td->td_proc;
732
733	/* Lock proctree before locking the process. */
734	switch (req) {
735	case PT_TRACE_ME:
736	case PT_ATTACH:
737	case PT_STEP:
738	case PT_CONTINUE:
739	case PT_TO_SCE:
740	case PT_TO_SCX:
741	case PT_SYSCALL:
742	case PT_FOLLOW_FORK:
743	case PT_LWP_EVENTS:
744	case PT_GET_EVENT_MASK:
745	case PT_SET_EVENT_MASK:
746	case PT_DETACH:
747	case PT_GET_SC_ARGS:
748		sx_xlock(&proctree_lock);
749		proctree_locked = 1;
750		break;
751	default:
752		break;
753	}
754
755	if (req == PT_TRACE_ME) {
756		p = td->td_proc;
757		PROC_LOCK(p);
758	} else {
759		if (pid <= PID_MAX) {
760			if ((p = pfind(pid)) == NULL) {
761				if (proctree_locked)
762					sx_xunlock(&proctree_lock);
763				return (ESRCH);
764			}
765		} else {
766			td2 = tdfind(pid, -1);
767			if (td2 == NULL) {
768				if (proctree_locked)
769					sx_xunlock(&proctree_lock);
770				return (ESRCH);
771			}
772			p = td2->td_proc;
773			tid = pid;
774			pid = p->p_pid;
775		}
776	}
777	AUDIT_ARG_PROCESS(p);
778
779	if ((p->p_flag & P_WEXIT) != 0) {
780		error = ESRCH;
781		goto fail;
782	}
783	if ((error = p_cansee(td, p)) != 0)
784		goto fail;
785
786	if ((error = p_candebug(td, p)) != 0)
787		goto fail;
788
789	/*
790	 * System processes can't be debugged.
791	 */
792	if ((p->p_flag & P_SYSTEM) != 0) {
793		error = EINVAL;
794		goto fail;
795	}
796
797	if (tid == 0) {
798		if ((p->p_flag & P_STOPPED_TRACE) != 0) {
799			KASSERT(p->p_xthread != NULL, ("NULL p_xthread"));
800			td2 = p->p_xthread;
801		} else {
802			td2 = FIRST_THREAD_IN_PROC(p);
803		}
804		tid = td2->td_tid;
805	}
806
807#ifdef COMPAT_FREEBSD32
808	/*
809	 * Test if we're a 32 bit client and what the target is.
810	 * Set the wrap controls accordingly.
811	 */
812	if (SV_CURPROC_FLAG(SV_ILP32)) {
813		if (SV_PROC_FLAG(td2->td_proc, SV_ILP32))
814			safe = 1;
815		wrap32 = 1;
816	}
817#endif
818	/*
819	 * Permissions check
820	 */
821	switch (req) {
822	case PT_TRACE_ME:
823		/*
824		 * Always legal, when there is a parent process which
825		 * could trace us.  Otherwise, reject.
826		 */
827		if ((p->p_flag & P_TRACED) != 0) {
828			error = EBUSY;
829			goto fail;
830		}
831		if (p->p_pptr == initproc) {
832			error = EPERM;
833			goto fail;
834		}
835		break;
836
837	case PT_ATTACH:
838		/* Self */
839		if (p == td->td_proc) {
840			error = EINVAL;
841			goto fail;
842		}
843
844		/* Already traced */
845		if (p->p_flag & P_TRACED) {
846			error = EBUSY;
847			goto fail;
848		}
849
850		/* Can't trace an ancestor if you're being traced. */
851		if (curp->p_flag & P_TRACED) {
852			for (pp = curp->p_pptr; pp != NULL; pp = pp->p_pptr) {
853				if (pp == p) {
854					error = EINVAL;
855					goto fail;
856				}
857			}
858		}
859
860
861		/* OK */
862		break;
863
864	case PT_CLEARSTEP:
865		/* Allow thread to clear single step for itself */
866		if (td->td_tid == tid)
867			break;
868
869		/* FALLTHROUGH */
870	default:
871		/* not being traced... */
872		if ((p->p_flag & P_TRACED) == 0) {
873			error = EPERM;
874			goto fail;
875		}
876
877		/* not being traced by YOU */
878		if (p->p_pptr != td->td_proc) {
879			error = EBUSY;
880			goto fail;
881		}
882
883		/* not currently stopped */
884		if ((p->p_flag & P_STOPPED_TRACE) == 0 ||
885		    p->p_suspcount != p->p_numthreads  ||
886		    (p->p_flag & P_WAITED) == 0) {
887			error = EBUSY;
888			goto fail;
889		}
890
891		/* OK */
892		break;
893	}
894
895	/* Keep this process around until we finish this request. */
896	_PHOLD(p);
897
898#ifdef FIX_SSTEP
899	/*
900	 * Single step fixup ala procfs
901	 */
902	FIX_SSTEP(td2);
903#endif
904
905	/*
906	 * Actually do the requests
907	 */
908
909	td->td_retval[0] = 0;
910
911	switch (req) {
912	case PT_TRACE_ME:
913		/* set my trace flag and "owner" so it can read/write me */
914		proc_set_traced(p, false);
915		if (p->p_flag & P_PPWAIT)
916			p->p_flag |= P_PPTRACE;
917		CTR1(KTR_PTRACE, "PT_TRACE_ME: pid %d", p->p_pid);
918		break;
919
920	case PT_ATTACH:
921		/* security check done above */
922		/*
923		 * It would be nice if the tracing relationship was separate
924		 * from the parent relationship but that would require
925		 * another set of links in the proc struct or for "wait"
926		 * to scan the entire proc table.  To make life easier,
927		 * we just re-parent the process we're trying to trace.
928		 * The old parent is remembered so we can put things back
929		 * on a "detach".
930		 */
931		proc_set_traced(p, true);
932		if (p->p_pptr != td->td_proc) {
933			proc_reparent(p, td->td_proc);
934		}
935		CTR2(KTR_PTRACE, "PT_ATTACH: pid %d, oppid %d", p->p_pid,
936		    p->p_oppid);
937
938		sx_xunlock(&proctree_lock);
939		proctree_locked = 0;
940		MPASS(p->p_xthread == NULL);
941		MPASS((p->p_flag & P_STOPPED_TRACE) == 0);
942
943		/*
944		 * If already stopped due to a stop signal, clear the
945		 * existing stop before triggering a traced SIGSTOP.
946		 */
947		if ((p->p_flag & P_STOPPED_SIG) != 0) {
948			PROC_SLOCK(p);
949			p->p_flag &= ~(P_STOPPED_SIG | P_WAITED);
950			thread_unsuspend(p);
951			PROC_SUNLOCK(p);
952		}
953
954		kern_psignal(p, SIGSTOP);
955		break;
956
957	case PT_CLEARSTEP:
958		CTR2(KTR_PTRACE, "PT_CLEARSTEP: tid %d (pid %d)", td2->td_tid,
959		    p->p_pid);
960		error = ptrace_clear_single_step(td2);
961		break;
962
963	case PT_SETSTEP:
964		CTR2(KTR_PTRACE, "PT_SETSTEP: tid %d (pid %d)", td2->td_tid,
965		    p->p_pid);
966		error = ptrace_single_step(td2);
967		break;
968
969	case PT_SUSPEND:
970		CTR2(KTR_PTRACE, "PT_SUSPEND: tid %d (pid %d)", td2->td_tid,
971		    p->p_pid);
972		td2->td_dbgflags |= TDB_SUSPEND;
973		thread_lock(td2);
974		td2->td_flags |= TDF_NEEDSUSPCHK;
975		thread_unlock(td2);
976		break;
977
978	case PT_RESUME:
979		CTR2(KTR_PTRACE, "PT_RESUME: tid %d (pid %d)", td2->td_tid,
980		    p->p_pid);
981		td2->td_dbgflags &= ~TDB_SUSPEND;
982		break;
983
984	case PT_FOLLOW_FORK:
985		CTR3(KTR_PTRACE, "PT_FOLLOW_FORK: pid %d %s -> %s", p->p_pid,
986		    p->p_ptevents & PTRACE_FORK ? "enabled" : "disabled",
987		    data ? "enabled" : "disabled");
988		if (data)
989			p->p_ptevents |= PTRACE_FORK;
990		else
991			p->p_ptevents &= ~PTRACE_FORK;
992		break;
993
994	case PT_LWP_EVENTS:
995		CTR3(KTR_PTRACE, "PT_LWP_EVENTS: pid %d %s -> %s", p->p_pid,
996		    p->p_ptevents & PTRACE_LWP ? "enabled" : "disabled",
997		    data ? "enabled" : "disabled");
998		if (data)
999			p->p_ptevents |= PTRACE_LWP;
1000		else
1001			p->p_ptevents &= ~PTRACE_LWP;
1002		break;
1003
1004	case PT_GET_EVENT_MASK:
1005		if (data != sizeof(p->p_ptevents)) {
1006			error = EINVAL;
1007			break;
1008		}
1009		CTR2(KTR_PTRACE, "PT_GET_EVENT_MASK: pid %d mask %#x", p->p_pid,
1010		    p->p_ptevents);
1011		*(int *)addr = p->p_ptevents;
1012		break;
1013
1014	case PT_SET_EVENT_MASK:
1015		if (data != sizeof(p->p_ptevents)) {
1016			error = EINVAL;
1017			break;
1018		}
1019		tmp = *(int *)addr;
1020		if ((tmp & ~(PTRACE_EXEC | PTRACE_SCE | PTRACE_SCX |
1021		    PTRACE_FORK | PTRACE_LWP | PTRACE_VFORK)) != 0) {
1022			error = EINVAL;
1023			break;
1024		}
1025		CTR3(KTR_PTRACE, "PT_SET_EVENT_MASK: pid %d mask %#x -> %#x",
1026		    p->p_pid, p->p_ptevents, tmp);
1027		p->p_ptevents = tmp;
1028		break;
1029
1030	case PT_GET_SC_ARGS:
1031		CTR1(KTR_PTRACE, "PT_GET_SC_ARGS: pid %d", p->p_pid);
1032		if ((td2->td_dbgflags & (TDB_SCE | TDB_SCX)) == 0
1033#ifdef COMPAT_FREEBSD32
1034		    || (wrap32 && !safe)
1035#endif
1036		    ) {
1037			error = EINVAL;
1038			break;
1039		}
1040		bzero(addr, sizeof(td2->td_sa.args));
1041#ifdef COMPAT_FREEBSD32
1042		if (wrap32)
1043			for (num = 0; num < nitems(td2->td_sa.args); num++)
1044				((uint32_t *)addr)[num] = (uint32_t)
1045				    td2->td_sa.args[num];
1046		else
1047#endif
1048			bcopy(td2->td_sa.args, addr, td2->td_sa.narg *
1049			    sizeof(register_t));
1050		break;
1051
1052	case PT_STEP:
1053	case PT_CONTINUE:
1054	case PT_TO_SCE:
1055	case PT_TO_SCX:
1056	case PT_SYSCALL:
1057	case PT_DETACH:
1058		/* Zero means do not send any signal */
1059		if (data < 0 || data > _SIG_MAXSIG) {
1060			error = EINVAL;
1061			break;
1062		}
1063
1064		switch (req) {
1065		case PT_STEP:
1066			CTR3(KTR_PTRACE, "PT_STEP: tid %d (pid %d), sig = %d",
1067			    td2->td_tid, p->p_pid, data);
1068			error = ptrace_single_step(td2);
1069			if (error)
1070				goto out;
1071			break;
1072		case PT_CONTINUE:
1073		case PT_TO_SCE:
1074		case PT_TO_SCX:
1075		case PT_SYSCALL:
1076			if (addr != (void *)1) {
1077				error = ptrace_set_pc(td2,
1078				    (u_long)(uintfptr_t)addr);
1079				if (error)
1080					goto out;
1081			}
1082			switch (req) {
1083			case PT_TO_SCE:
1084				p->p_ptevents |= PTRACE_SCE;
1085				CTR4(KTR_PTRACE,
1086		    "PT_TO_SCE: pid %d, events = %#x, PC = %#lx, sig = %d",
1087				    p->p_pid, p->p_ptevents,
1088				    (u_long)(uintfptr_t)addr, data);
1089				break;
1090			case PT_TO_SCX:
1091				p->p_ptevents |= PTRACE_SCX;
1092				CTR4(KTR_PTRACE,
1093		    "PT_TO_SCX: pid %d, events = %#x, PC = %#lx, sig = %d",
1094				    p->p_pid, p->p_ptevents,
1095				    (u_long)(uintfptr_t)addr, data);
1096				break;
1097			case PT_SYSCALL:
1098				p->p_ptevents |= PTRACE_SYSCALL;
1099				CTR4(KTR_PTRACE,
1100		    "PT_SYSCALL: pid %d, events = %#x, PC = %#lx, sig = %d",
1101				    p->p_pid, p->p_ptevents,
1102				    (u_long)(uintfptr_t)addr, data);
1103				break;
1104			case PT_CONTINUE:
1105				CTR3(KTR_PTRACE,
1106				    "PT_CONTINUE: pid %d, PC = %#lx, sig = %d",
1107				    p->p_pid, (u_long)(uintfptr_t)addr, data);
1108				break;
1109			}
1110			break;
1111		case PT_DETACH:
1112			/*
1113			 * Reset the process parent.
1114			 *
1115			 * NB: This clears P_TRACED before reparenting
1116			 * a detached process back to its original
1117			 * parent.  Otherwise the debugee will be set
1118			 * as an orphan of the debugger.
1119			 */
1120			p->p_flag &= ~(P_TRACED | P_WAITED);
1121			if (p->p_oppid != p->p_pptr->p_pid) {
1122				PROC_LOCK(p->p_pptr);
1123				sigqueue_take(p->p_ksi);
1124				PROC_UNLOCK(p->p_pptr);
1125
1126				pp = proc_realparent(p);
1127				proc_reparent(p, pp);
1128				if (pp == initproc)
1129					p->p_sigparent = SIGCHLD;
1130				CTR3(KTR_PTRACE,
1131			    "PT_DETACH: pid %d reparented to pid %d, sig %d",
1132				    p->p_pid, pp->p_pid, data);
1133			} else
1134				CTR2(KTR_PTRACE, "PT_DETACH: pid %d, sig %d",
1135				    p->p_pid, data);
1136			p->p_oppid = 0;
1137			p->p_ptevents = 0;
1138			FOREACH_THREAD_IN_PROC(p, td3) {
1139				if ((td3->td_dbgflags & TDB_FSTP) != 0) {
1140					sigqueue_delete(&td3->td_sigqueue,
1141					    SIGSTOP);
1142				}
1143				td3->td_dbgflags &= ~(TDB_XSIG | TDB_FSTP |
1144				    TDB_SUSPEND);
1145			}
1146
1147			if ((p->p_flag2 & P2_PTRACE_FSTP) != 0) {
1148				sigqueue_delete(&p->p_sigqueue, SIGSTOP);
1149				p->p_flag2 &= ~P2_PTRACE_FSTP;
1150			}
1151
1152			/* should we send SIGCHLD? */
1153			/* childproc_continued(p); */
1154			break;
1155		}
1156
1157		sx_xunlock(&proctree_lock);
1158		proctree_locked = 0;
1159
1160	sendsig:
1161		MPASS(proctree_locked == 0);
1162
1163		/*
1164		 * Clear the pending event for the thread that just
1165		 * reported its event (p_xthread).  This may not be
1166		 * the thread passed to PT_CONTINUE, PT_STEP, etc. if
1167		 * the debugger is resuming a different thread.
1168		 *
1169		 * Deliver any pending signal via the reporting thread.
1170		 */
1171		MPASS(p->p_xthread != NULL);
1172		p->p_xthread->td_dbgflags &= ~TDB_XSIG;
1173		p->p_xthread->td_xsig = data;
1174		p->p_xthread = NULL;
1175		p->p_xsig = data;
1176
1177		/*
1178		 * P_WKILLED is insurance that a PT_KILL/SIGKILL
1179		 * always works immediately, even if another thread is
1180		 * unsuspended first and attempts to handle a
1181		 * different signal or if the POSIX.1b style signal
1182		 * queue cannot accommodate any new signals.
1183		 */
1184		if (data == SIGKILL)
1185			proc_wkilled(p);
1186
1187		/*
1188		 * Unsuspend all threads.  To leave a thread
1189		 * suspended, use PT_SUSPEND to suspend it before
1190		 * continuing the process.
1191		 */
1192		PROC_SLOCK(p);
1193		p->p_flag &= ~(P_STOPPED_TRACE | P_STOPPED_SIG | P_WAITED);
1194		thread_unsuspend(p);
1195		PROC_SUNLOCK(p);
1196		break;
1197
1198	case PT_WRITE_I:
1199	case PT_WRITE_D:
1200		td2->td_dbgflags |= TDB_USERWR;
1201		PROC_UNLOCK(p);
1202		error = 0;
1203		if (proc_writemem(td, p, (off_t)(uintptr_t)addr, &data,
1204		    sizeof(int)) != sizeof(int))
1205			error = ENOMEM;
1206		else
1207			CTR3(KTR_PTRACE, "PT_WRITE: pid %d: %p <= %#x",
1208			    p->p_pid, addr, data);
1209		PROC_LOCK(p);
1210		break;
1211
1212	case PT_READ_I:
1213	case PT_READ_D:
1214		PROC_UNLOCK(p);
1215		error = tmp = 0;
1216		if (proc_readmem(td, p, (off_t)(uintptr_t)addr, &tmp,
1217		    sizeof(int)) != sizeof(int))
1218			error = ENOMEM;
1219		else
1220			CTR3(KTR_PTRACE, "PT_READ: pid %d: %p >= %#x",
1221			    p->p_pid, addr, tmp);
1222		td->td_retval[0] = tmp;
1223		PROC_LOCK(p);
1224		break;
1225
1226	case PT_IO:
1227#ifdef COMPAT_FREEBSD32
1228		if (wrap32) {
1229			piod32 = addr;
1230			iov.iov_base = (void *)(uintptr_t)piod32->piod_addr;
1231			iov.iov_len = piod32->piod_len;
1232			uio.uio_offset = (off_t)(uintptr_t)piod32->piod_offs;
1233			uio.uio_resid = piod32->piod_len;
1234		} else
1235#endif
1236		{
1237			piod = addr;
1238			iov.iov_base = piod->piod_addr;
1239			iov.iov_len = piod->piod_len;
1240			uio.uio_offset = (off_t)(uintptr_t)piod->piod_offs;
1241			uio.uio_resid = piod->piod_len;
1242		}
1243		uio.uio_iov = &iov;
1244		uio.uio_iovcnt = 1;
1245		uio.uio_segflg = UIO_USERSPACE;
1246		uio.uio_td = td;
1247#ifdef COMPAT_FREEBSD32
1248		tmp = wrap32 ? piod32->piod_op : piod->piod_op;
1249#else
1250		tmp = piod->piod_op;
1251#endif
1252		switch (tmp) {
1253		case PIOD_READ_D:
1254		case PIOD_READ_I:
1255			CTR3(KTR_PTRACE, "PT_IO: pid %d: READ (%p, %#x)",
1256			    p->p_pid, (uintptr_t)uio.uio_offset, uio.uio_resid);
1257			uio.uio_rw = UIO_READ;
1258			break;
1259		case PIOD_WRITE_D:
1260		case PIOD_WRITE_I:
1261			CTR3(KTR_PTRACE, "PT_IO: pid %d: WRITE (%p, %#x)",
1262			    p->p_pid, (uintptr_t)uio.uio_offset, uio.uio_resid);
1263			td2->td_dbgflags |= TDB_USERWR;
1264			uio.uio_rw = UIO_WRITE;
1265			break;
1266		default:
1267			error = EINVAL;
1268			goto out;
1269		}
1270		PROC_UNLOCK(p);
1271		error = proc_rwmem(p, &uio);
1272#ifdef COMPAT_FREEBSD32
1273		if (wrap32)
1274			piod32->piod_len -= uio.uio_resid;
1275		else
1276#endif
1277			piod->piod_len -= uio.uio_resid;
1278		PROC_LOCK(p);
1279		break;
1280
1281	case PT_KILL:
1282		CTR1(KTR_PTRACE, "PT_KILL: pid %d", p->p_pid);
1283		data = SIGKILL;
1284		goto sendsig;	/* in PT_CONTINUE above */
1285
1286	case PT_SETREGS:
1287		CTR2(KTR_PTRACE, "PT_SETREGS: tid %d (pid %d)", td2->td_tid,
1288		    p->p_pid);
1289		td2->td_dbgflags |= TDB_USERWR;
1290		error = PROC_WRITE(regs, td2, addr);
1291		break;
1292
1293	case PT_GETREGS:
1294		CTR2(KTR_PTRACE, "PT_GETREGS: tid %d (pid %d)", td2->td_tid,
1295		    p->p_pid);
1296		error = PROC_READ(regs, td2, addr);
1297		break;
1298
1299	case PT_SETFPREGS:
1300		CTR2(KTR_PTRACE, "PT_SETFPREGS: tid %d (pid %d)", td2->td_tid,
1301		    p->p_pid);
1302		td2->td_dbgflags |= TDB_USERWR;
1303		error = PROC_WRITE(fpregs, td2, addr);
1304		break;
1305
1306	case PT_GETFPREGS:
1307		CTR2(KTR_PTRACE, "PT_GETFPREGS: tid %d (pid %d)", td2->td_tid,
1308		    p->p_pid);
1309		error = PROC_READ(fpregs, td2, addr);
1310		break;
1311
1312	case PT_SETDBREGS:
1313		CTR2(KTR_PTRACE, "PT_SETDBREGS: tid %d (pid %d)", td2->td_tid,
1314		    p->p_pid);
1315		td2->td_dbgflags |= TDB_USERWR;
1316		error = PROC_WRITE(dbregs, td2, addr);
1317		break;
1318
1319	case PT_GETDBREGS:
1320		CTR2(KTR_PTRACE, "PT_GETDBREGS: tid %d (pid %d)", td2->td_tid,
1321		    p->p_pid);
1322		error = PROC_READ(dbregs, td2, addr);
1323		break;
1324
1325	case PT_LWPINFO:
1326		if (data <= 0 ||
1327#ifdef COMPAT_FREEBSD32
1328		    (!wrap32 && data > sizeof(*pl)) ||
1329		    (wrap32 && data > sizeof(*pl32))) {
1330#else
1331		    data > sizeof(*pl)) {
1332#endif
1333			error = EINVAL;
1334			break;
1335		}
1336#ifdef COMPAT_FREEBSD32
1337		if (wrap32) {
1338			pl = &plr;
1339			pl32 = addr;
1340		} else
1341#endif
1342		pl = addr;
1343		bzero(pl, sizeof(*pl));
1344		pl->pl_lwpid = td2->td_tid;
1345		pl->pl_event = PL_EVENT_NONE;
1346		pl->pl_flags = 0;
1347		if (td2->td_dbgflags & TDB_XSIG) {
1348			pl->pl_event = PL_EVENT_SIGNAL;
1349			if (td2->td_si.si_signo != 0 &&
1350#ifdef COMPAT_FREEBSD32
1351			    ((!wrap32 && data >= offsetof(struct ptrace_lwpinfo,
1352			    pl_siginfo) + sizeof(pl->pl_siginfo)) ||
1353			    (wrap32 && data >= offsetof(struct ptrace_lwpinfo32,
1354			    pl_siginfo) + sizeof(struct siginfo32)))
1355#else
1356			    data >= offsetof(struct ptrace_lwpinfo, pl_siginfo)
1357			    + sizeof(pl->pl_siginfo)
1358#endif
1359			){
1360				pl->pl_flags |= PL_FLAG_SI;
1361				pl->pl_siginfo = td2->td_si;
1362			}
1363		}
1364		if (td2->td_dbgflags & TDB_SCE)
1365			pl->pl_flags |= PL_FLAG_SCE;
1366		else if (td2->td_dbgflags & TDB_SCX)
1367			pl->pl_flags |= PL_FLAG_SCX;
1368		if (td2->td_dbgflags & TDB_EXEC)
1369			pl->pl_flags |= PL_FLAG_EXEC;
1370		if (td2->td_dbgflags & TDB_FORK) {
1371			pl->pl_flags |= PL_FLAG_FORKED;
1372			pl->pl_child_pid = td2->td_dbg_forked;
1373			if (td2->td_dbgflags & TDB_VFORK)
1374				pl->pl_flags |= PL_FLAG_VFORKED;
1375		} else if ((td2->td_dbgflags & (TDB_SCX | TDB_VFORK)) ==
1376		    TDB_VFORK)
1377			pl->pl_flags |= PL_FLAG_VFORK_DONE;
1378		if (td2->td_dbgflags & TDB_CHILD)
1379			pl->pl_flags |= PL_FLAG_CHILD;
1380		if (td2->td_dbgflags & TDB_BORN)
1381			pl->pl_flags |= PL_FLAG_BORN;
1382		if (td2->td_dbgflags & TDB_EXIT)
1383			pl->pl_flags |= PL_FLAG_EXITED;
1384		pl->pl_sigmask = td2->td_sigmask;
1385		pl->pl_siglist = td2->td_siglist;
1386		strcpy(pl->pl_tdname, td2->td_name);
1387		if ((td2->td_dbgflags & (TDB_SCE | TDB_SCX)) != 0) {
1388			pl->pl_syscall_code = td2->td_sa.code;
1389			pl->pl_syscall_narg = td2->td_sa.narg;
1390		} else {
1391			pl->pl_syscall_code = 0;
1392			pl->pl_syscall_narg = 0;
1393		}
1394#ifdef COMPAT_FREEBSD32
1395		if (wrap32)
1396			ptrace_lwpinfo_to32(pl, pl32);
1397#endif
1398		CTR6(KTR_PTRACE,
1399    "PT_LWPINFO: tid %d (pid %d) event %d flags %#x child pid %d syscall %d",
1400		    td2->td_tid, p->p_pid, pl->pl_event, pl->pl_flags,
1401		    pl->pl_child_pid, pl->pl_syscall_code);
1402		break;
1403
1404	case PT_GETNUMLWPS:
1405		CTR2(KTR_PTRACE, "PT_GETNUMLWPS: pid %d: %d threads", p->p_pid,
1406		    p->p_numthreads);
1407		td->td_retval[0] = p->p_numthreads;
1408		break;
1409
1410	case PT_GETLWPLIST:
1411		CTR3(KTR_PTRACE, "PT_GETLWPLIST: pid %d: data %d, actual %d",
1412		    p->p_pid, data, p->p_numthreads);
1413		if (data <= 0) {
1414			error = EINVAL;
1415			break;
1416		}
1417		num = imin(p->p_numthreads, data);
1418		PROC_UNLOCK(p);
1419		buf = malloc(num * sizeof(lwpid_t), M_TEMP, M_WAITOK);
1420		tmp = 0;
1421		PROC_LOCK(p);
1422		FOREACH_THREAD_IN_PROC(p, td2) {
1423			if (tmp >= num)
1424				break;
1425			buf[tmp++] = td2->td_tid;
1426		}
1427		PROC_UNLOCK(p);
1428		error = copyout(buf, addr, tmp * sizeof(lwpid_t));
1429		free(buf, M_TEMP);
1430		if (!error)
1431			td->td_retval[0] = tmp;
1432		PROC_LOCK(p);
1433		break;
1434
1435	case PT_VM_TIMESTAMP:
1436		CTR2(KTR_PTRACE, "PT_VM_TIMESTAMP: pid %d: timestamp %d",
1437		    p->p_pid, p->p_vmspace->vm_map.timestamp);
1438		td->td_retval[0] = p->p_vmspace->vm_map.timestamp;
1439		break;
1440
1441	case PT_VM_ENTRY:
1442		PROC_UNLOCK(p);
1443#ifdef COMPAT_FREEBSD32
1444		if (wrap32)
1445			error = ptrace_vm_entry32(td, p, addr);
1446		else
1447#endif
1448		error = ptrace_vm_entry(td, p, addr);
1449		PROC_LOCK(p);
1450		break;
1451
1452	default:
1453#ifdef __HAVE_PTRACE_MACHDEP
1454		if (req >= PT_FIRSTMACH) {
1455			PROC_UNLOCK(p);
1456			error = cpu_ptrace(td2, req, addr, data);
1457			PROC_LOCK(p);
1458		} else
1459#endif
1460			/* Unknown request. */
1461			error = EINVAL;
1462		break;
1463	}
1464
1465out:
1466	/* Drop our hold on this process now that the request has completed. */
1467	_PRELE(p);
1468fail:
1469	PROC_UNLOCK(p);
1470	if (proctree_locked)
1471		sx_xunlock(&proctree_lock);
1472	return (error);
1473}
1474#undef PROC_READ
1475#undef PROC_WRITE
1476
1477/*
1478 * Stop a process because of a debugging event;
1479 * stay stopped until p->p_step is cleared
1480 * (cleared by PIOCCONT in procfs).
1481 */
1482void
1483stopevent(struct proc *p, unsigned int event, unsigned int val)
1484{
1485
1486	PROC_LOCK_ASSERT(p, MA_OWNED);
1487	p->p_step = 1;
1488	CTR3(KTR_PTRACE, "stopevent: pid %d event %u val %u", p->p_pid, event,
1489	    val);
1490	do {
1491		if (event != S_EXIT)
1492			p->p_xsig = val;
1493		p->p_xthread = NULL;
1494		p->p_stype = event;	/* Which event caused the stop? */
1495		wakeup(&p->p_stype);	/* Wake up any PIOCWAIT'ing procs */
1496		msleep(&p->p_step, &p->p_mtx, PWAIT, "stopevent", 0);
1497	} while (p->p_step);
1498}
1499