xref: /dragonfly/sys/kern/sys_process.c (revision 92fc8b5c) 
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  * $FreeBSD: src/sys/kern/sys_process.c,v 1.51.2.6 2003/01/08 03:06:45 kan Exp $
32  * $DragonFly: src/sys/kern/sys_process.c,v 1.30 2007/02/19 01:14:23 corecode Exp $
33  */
34 
35 #include <sys/param.h>
36 #include <sys/systm.h>
37 #include <sys/sysproto.h>
38 #include <sys/proc.h>
39 #include <sys/priv.h>
40 #include <sys/vnode.h>
41 #include <sys/ptrace.h>
42 #include <sys/reg.h>
43 #include <sys/lock.h>
44 
45 #include <vm/vm.h>
46 #include <vm/pmap.h>
47 #include <vm/vm_map.h>
48 #include <vm/vm_page.h>
49 
50 #include <sys/user.h>
51 #include <vfs/procfs/procfs.h>
52 
53 #include <sys/thread2.h>
54 #include <sys/spinlock2.h>
55 
56 /* use the equivalent procfs code */
57 #if 0
58 static int
59 pread (struct proc *procp, unsigned int addr, unsigned int *retval) {
60 	int		rv;
61 	vm_map_t	map, tmap;
62 	vm_object_t	object;
63 	vm_offset_t	kva = 0;
64 	int		page_offset;	/* offset into page */
65 	vm_offset_t	pageno;		/* page number */
66 	vm_map_entry_t	out_entry;
67 	vm_prot_t	out_prot;
68 	boolean_t	wired;
69 	vm_pindex_t	pindex;
70 
71 	/* Map page into kernel space */
72 
73 	map = &procp->p_vmspace->vm_map;
74 
75 	page_offset = addr - trunc_page(addr);
76 	pageno = trunc_page(addr);
77 
78 	tmap = map;
79 	rv = vm_map_lookup (&tmap, pageno, VM_PROT_READ, &out_entry,
80 		&object, &pindex, &out_prot, &wired);
81 
82 	if (rv != KERN_SUCCESS)
83 		return EINVAL;
84 
85 	vm_map_lookup_done (tmap, out_entry, 0);
86 
87 	/* Find space in kernel_map for the page we're interested in */
88 	rv = vm_map_find (&kernel_map, object, IDX_TO_OFF(pindex),
89 			  &kva,
90 			  PAGE_SIZE, PAGE_SIZE,
91 			  0, VM_MAPTYPE_NORMAL,
92 			  VM_PROT_ALL, VM_PROT_ALL,
93 			  0);
94 
95 	if (!rv) {
96 		vm_object_reference (object);
97 
98 		rv = vm_map_wire (&kernel_map, kva, kva + PAGE_SIZE, 0);
99 		if (!rv) {
100 			*retval = 0;
101 			bcopy ((caddr_t)kva + page_offset,
102 			       retval, sizeof *retval);
103 		}
104 		vm_map_remove (&kernel_map, kva, kva + PAGE_SIZE);
105 	}
106 
107 	return rv;
108 }
109 
110 static int
111 pwrite (struct proc *procp, unsigned int addr, unsigned int datum) {
112 	int		rv;
113 	vm_map_t	map, tmap;
114 	vm_object_t	object;
115 	vm_offset_t	kva = 0;
116 	int		page_offset;	/* offset into page */
117 	vm_offset_t	pageno;		/* page number */
118 	vm_map_entry_t	out_entry;
119 	vm_prot_t	out_prot;
120 	boolean_t	wired;
121 	vm_pindex_t	pindex;
122 	boolean_t	fix_prot = 0;
123 
124 	/* Map page into kernel space */
125 
126 	map = &procp->p_vmspace->vm_map;
127 
128 	page_offset = addr - trunc_page(addr);
129 	pageno = trunc_page(addr);
130 
131 	/*
132 	 * Check the permissions for the area we're interested in.
133 	 */
134 
135 	if (vm_map_check_protection (map, pageno, pageno + PAGE_SIZE,
136 				     VM_PROT_WRITE, FALSE) == FALSE) {
137 		/*
138 		 * If the page was not writable, we make it so.
139 		 * XXX It is possible a page may *not* be read/executable,
140 		 * if a process changes that!
141 		 */
142 		fix_prot = 1;
143 		/* The page isn't writable, so let's try making it so... */
144 		if ((rv = vm_map_protect (map, pageno, pageno + PAGE_SIZE,
145 			VM_PROT_ALL, 0)) != KERN_SUCCESS)
146 		  return EFAULT;	/* I guess... */
147 	}
148 
149 	/*
150 	 * Now we need to get the page.  out_entry, out_prot, wired, and
151 	 * single_use aren't used.  One would think the vm code would be
152 	 * a *bit* nicer...  We use tmap because vm_map_lookup() can
153 	 * change the map argument.
154 	 */
155 
156 	tmap = map;
157 	rv = vm_map_lookup (&tmap, pageno, VM_PROT_WRITE, &out_entry,
158 		&object, &pindex, &out_prot, &wired);
159 	if (rv != KERN_SUCCESS) {
160 		return EINVAL;
161 	}
162 
163 	/*
164 	 * Okay, we've got the page.  Let's release tmap.
165 	 */
166 
167 	vm_map_lookup_done (tmap, out_entry, 0);
168 
169 	/*
170 	 * Fault the page in...
171 	 */
172 
173 	rv = vm_fault(map, pageno, VM_PROT_WRITE|VM_PROT_READ, FALSE);
174 	if (rv != KERN_SUCCESS)
175 		return EFAULT;
176 
177 	/* Find space in kernel_map for the page we're interested in */
178 	rv = vm_map_find (&kernel_map, object, IDX_TO_OFF(pindex),
179 			  &kva,
180 			  PAGE_SIZE, PAGE_SIZE,
181 			  0, VM_MAPTYPE_NORMAL,
182 			  VM_PROT_ALL, VM_PROT_ALL,
183 			  0);
184 	if (!rv) {
185 		vm_object_reference (object);
186 
187 		rv = vm_map_wire (&kernel_map, kva, kva + PAGE_SIZE, 0);
188 		if (!rv) {
189 		  bcopy (&datum, (caddr_t)kva + page_offset, sizeof datum);
190 		}
191 		vm_map_remove (&kernel_map, kva, kva + PAGE_SIZE);
192 	}
193 
194 	if (fix_prot)
195 		vm_map_protect (map, pageno, pageno + PAGE_SIZE,
196 			VM_PROT_READ|VM_PROT_EXECUTE, 0);
197 	return rv;
198 }
199 #endif
200 
201 /*
202  * Process debugging system call.
203  *
204  * MPALMOSTSAFE
205  */
206 int
207 sys_ptrace(struct ptrace_args *uap)
208 {
209 	struct proc *p = curproc;
210 
211 	/*
212 	 * XXX this obfuscation is to reduce stack usage, but the register
213 	 * structs may be too large to put on the stack anyway.
214 	 */
215 	union {
216 		struct ptrace_io_desc piod;
217 		struct dbreg dbreg;
218 		struct fpreg fpreg;
219 		struct reg reg;
220 	} r;
221 	void *addr;
222 	int error = 0;
223 
224 	addr = &r;
225 	switch (uap->req) {
226 	case PT_GETREGS:
227 	case PT_GETFPREGS:
228 #ifdef PT_GETDBREGS
229 	case PT_GETDBREGS:
230 #endif
231 		break;
232 	case PT_SETREGS:
233 		error = copyin(uap->addr, &r.reg, sizeof r.reg);
234 		break;
235 	case PT_SETFPREGS:
236 		error = copyin(uap->addr, &r.fpreg, sizeof r.fpreg);
237 		break;
238 #ifdef PT_SETDBREGS
239 	case PT_SETDBREGS:
240 		error = copyin(uap->addr, &r.dbreg, sizeof r.dbreg);
241 		break;
242 #endif
243 	case PT_IO:
244 		error = copyin(uap->addr, &r.piod, sizeof r.piod);
245 		break;
246 	default:
247 		addr = uap->addr;
248 	}
249 	if (error)
250 		return (error);
251 
252 	error = kern_ptrace(p, uap->req, uap->pid, addr, uap->data,
253 			&uap->sysmsg_result);
254 	if (error)
255 		return (error);
256 
257 	switch (uap->req) {
258 	case PT_IO:
259 		(void)copyout(&r.piod, uap->addr, sizeof r.piod);
260 		break;
261 	case PT_GETREGS:
262 		error = copyout(&r.reg, uap->addr, sizeof r.reg);
263 		break;
264 	case PT_GETFPREGS:
265 		error = copyout(&r.fpreg, uap->addr, sizeof r.fpreg);
266 		break;
267 #ifdef PT_GETDBREGS
268 	case PT_GETDBREGS:
269 		error = copyout(&r.dbreg, uap->addr, sizeof r.dbreg);
270 		break;
271 #endif
272 	}
273 
274 	return (error);
275 }
276 
277 int
278 kern_ptrace(struct proc *curp, int req, pid_t pid, void *addr,
279 	    int data, int *res)
280 {
281 	struct proc *p, *pp;
282 	struct lwp *lp;
283 	struct iovec iov;
284 	struct uio uio;
285 	struct ptrace_io_desc *piod;
286 	int error = 0;
287 	int write, tmp;
288 	int t;
289 
290 	lwkt_gettoken(&proc_token);
291 
292 	write = 0;
293 	if (req == PT_TRACE_ME) {
294 		p = curp;
295 		PHOLD(p);
296 	} else {
297 		if ((p = pfind(pid)) == NULL) {
298 			lwkt_reltoken(&proc_token);
299 			return ESRCH;
300 		}
301 	}
302 	if (!PRISON_CHECK(curp->p_ucred, p->p_ucred)) {
303 		PRELE(p);
304 		lwkt_reltoken(&proc_token);
305 		return (ESRCH);
306 	}
307 
308 	lwkt_gettoken(&p->p_token);
309 	/* Can't trace a process that's currently exec'ing. */
310 	if ((p->p_flag & P_INEXEC) != 0) {
311 		lwkt_reltoken(&p->p_token);
312 		PRELE(p);
313 		lwkt_reltoken(&proc_token);
314 		return EAGAIN;
315 	}
316 
317 	/*
318 	 * Permissions check
319 	 */
320 	switch (req) {
321 	case PT_TRACE_ME:
322 		/* Always legal. */
323 		break;
324 
325 	case PT_ATTACH:
326 		/* Self */
327 		if (p->p_pid == curp->p_pid) {
328 			lwkt_reltoken(&p->p_token);
329 			PRELE(p);
330 			lwkt_reltoken(&proc_token);
331 			return EINVAL;
332 		}
333 
334 		/* Already traced */
335 		if (p->p_flag & P_TRACED) {
336 			lwkt_reltoken(&p->p_token);
337 			PRELE(p);
338 			lwkt_reltoken(&proc_token);
339 			return EBUSY;
340 		}
341 
342 		if (curp->p_flag & P_TRACED)
343 			for (pp = curp->p_pptr; pp != NULL; pp = pp->p_pptr)
344 				if (pp == p) {
345 					lwkt_reltoken(&p->p_token);
346 					PRELE(p);
347 					lwkt_reltoken(&proc_token);
348 					return (EINVAL);
349 				}
350 
351 		/* not owned by you, has done setuid (unless you're root) */
352 		if ((p->p_ucred->cr_ruid != curp->p_ucred->cr_ruid) ||
353 		     (p->p_flag & P_SUGID)) {
354 			if ((error = priv_check_cred(curp->p_ucred, PRIV_ROOT, 0)) != 0) {
355 				lwkt_reltoken(&p->p_token);
356 				PRELE(p);
357 				lwkt_reltoken(&proc_token);
358 				return error;
359 			}
360 		}
361 
362 		/* can't trace init when securelevel > 0 */
363 		if (securelevel > 0 && p->p_pid == 1) {
364 			lwkt_reltoken(&p->p_token);
365 			PRELE(p);
366 			lwkt_reltoken(&proc_token);
367 			return EPERM;
368 		}
369 
370 		/* OK */
371 		break;
372 
373 	case PT_READ_I:
374 	case PT_READ_D:
375 	case PT_WRITE_I:
376 	case PT_WRITE_D:
377 	case PT_IO:
378 	case PT_CONTINUE:
379 	case PT_KILL:
380 	case PT_STEP:
381 	case PT_DETACH:
382 #ifdef PT_GETREGS
383 	case PT_GETREGS:
384 #endif
385 #ifdef PT_SETREGS
386 	case PT_SETREGS:
387 #endif
388 #ifdef PT_GETFPREGS
389 	case PT_GETFPREGS:
390 #endif
391 #ifdef PT_SETFPREGS
392 	case PT_SETFPREGS:
393 #endif
394 #ifdef PT_GETDBREGS
395 	case PT_GETDBREGS:
396 #endif
397 #ifdef PT_SETDBREGS
398 	case PT_SETDBREGS:
399 #endif
400 		/* not being traced... */
401 		if ((p->p_flag & P_TRACED) == 0) {
402 			lwkt_reltoken(&p->p_token);
403 			PRELE(p);
404 			lwkt_reltoken(&proc_token);
405 			return EPERM;
406 		}
407 
408 		/* not being traced by YOU */
409 		if (p->p_pptr != curp) {
410 			lwkt_reltoken(&p->p_token);
411 			PRELE(p);
412 			lwkt_reltoken(&proc_token);
413 			return EBUSY;
414 		}
415 
416 		/* not currently stopped */
417 		if (p->p_stat != SSTOP ||
418 		    (p->p_flag & P_WAITED) == 0) {
419 			lwkt_reltoken(&p->p_token);
420 			PRELE(p);
421 			lwkt_reltoken(&proc_token);
422 			return EBUSY;
423 		}
424 
425 		/* OK */
426 		break;
427 
428 	default:
429 		lwkt_reltoken(&p->p_token);
430 		PRELE(p);
431 		lwkt_reltoken(&proc_token);
432 		return EINVAL;
433 	}
434 
435 	/* XXX lwp */
436 	lp = FIRST_LWP_IN_PROC(p);
437 #ifdef FIX_SSTEP
438 	/*
439 	 * Single step fixup ala procfs
440 	 */
441 	FIX_SSTEP(lp);
442 #endif
443 
444 	/*
445 	 * Actually do the requests
446 	 */
447 
448 	*res = 0;
449 
450 	switch (req) {
451 	case PT_TRACE_ME:
452 		/* set my trace flag and "owner" so it can read/write me */
453 		p->p_flag |= P_TRACED;
454 		p->p_oppid = p->p_pptr->p_pid;
455 		lwkt_reltoken(&p->p_token);
456 		PRELE(p);
457 		lwkt_reltoken(&proc_token);
458 		return 0;
459 
460 	case PT_ATTACH:
461 		/* security check done above */
462 		p->p_flag |= P_TRACED;
463 		p->p_oppid = p->p_pptr->p_pid;
464 		if (p->p_pptr != curp)
465 			proc_reparent(p, curp);
466 		data = SIGSTOP;
467 		goto sendsig;	/* in PT_CONTINUE below */
468 
469 	case PT_STEP:
470 	case PT_CONTINUE:
471 	case PT_DETACH:
472 		/* Zero means do not send any signal */
473 		if (data < 0 || data > _SIG_MAXSIG) {
474 			lwkt_reltoken(&p->p_token);
475 			PRELE(p);
476 			lwkt_reltoken(&proc_token);
477 			return EINVAL;
478 		}
479 
480 		LWPHOLD(lp);
481 
482 		if (req == PT_STEP) {
483 			if ((error = ptrace_single_step (lp))) {
484 				LWPRELE(lp);
485 				lwkt_reltoken(&p->p_token);
486 				PRELE(p);
487 				lwkt_reltoken(&proc_token);
488 				return error;
489 			}
490 		}
491 
492 		if (addr != (void *)1) {
493 			if ((error = ptrace_set_pc (lp,
494 			    (u_long)(uintfptr_t)addr))) {
495 				LWPRELE(lp);
496 				lwkt_reltoken(&p->p_token);
497 				PRELE(p);
498 				lwkt_reltoken(&proc_token);
499 				return error;
500 			}
501 		}
502 		LWPRELE(lp);
503 
504 		if (req == PT_DETACH) {
505 			/* reset process parent */
506 			if (p->p_oppid != p->p_pptr->p_pid) {
507 				struct proc *pp;
508 
509 				pp = pfind(p->p_oppid);
510 				proc_reparent(p, pp ? pp : initproc);
511 				if (pp != NULL)
512 					PRELE(pp);
513 			}
514 
515 			p->p_flag &= ~(P_TRACED | P_WAITED);
516 			p->p_oppid = 0;
517 
518 			/* should we send SIGCHLD? */
519 		}
520 
521 	sendsig:
522 		/*
523 		 * Deliver or queue signal.  If the process is stopped
524 		 * force it to be SACTIVE again.
525 		 */
526 		crit_enter();
527 		if (p->p_stat == SSTOP) {
528 			p->p_xstat = data;
529 			lp->lwp_flag |= LWP_BREAKTSLEEP;
530 			proc_unstop(p);
531 		} else if (data) {
532 			ksignal(p, data);
533 		}
534 		crit_exit();
535 		lwkt_reltoken(&p->p_token);
536 		PRELE(p);
537 		lwkt_reltoken(&proc_token);
538 		return 0;
539 
540 	case PT_WRITE_I:
541 	case PT_WRITE_D:
542 		write = 1;
543 		/* fallthrough */
544 	case PT_READ_I:
545 	case PT_READ_D:
546 		/*
547 		 * NOTE! uio_offset represents the offset in the target
548 		 * process.  The iov is in the current process (the guy
549 		 * making the ptrace call) so uio_td must be the current
550 		 * process (though for a SYSSPACE transfer it doesn't
551 		 * really matter).
552 		 */
553 		tmp = 0;
554 		/* write = 0 set above */
555 		iov.iov_base = write ? (caddr_t)&data : (caddr_t)&tmp;
556 		iov.iov_len = sizeof(int);
557 		uio.uio_iov = &iov;
558 		uio.uio_iovcnt = 1;
559 		uio.uio_offset = (off_t)(uintptr_t)addr;
560 		uio.uio_resid = sizeof(int);
561 		uio.uio_segflg = UIO_SYSSPACE;
562 		uio.uio_rw = write ? UIO_WRITE : UIO_READ;
563 		uio.uio_td = curthread;
564 		error = procfs_domem(curp, lp, NULL, &uio);
565 		if (uio.uio_resid != 0) {
566 			/*
567 			 * XXX procfs_domem() doesn't currently return ENOSPC,
568 			 * so I think write() can bogusly return 0.
569 			 * XXX what happens for short writes?  We don't want
570 			 * to write partial data.
571 			 * XXX procfs_domem() returns EPERM for other invalid
572 			 * addresses.  Convert this to EINVAL.  Does this
573 			 * clobber returns of EPERM for other reasons?
574 			 */
575 			if (error == 0 || error == ENOSPC || error == EPERM)
576 				error = EINVAL;	/* EOF */
577 		}
578 		if (!write)
579 			*res = tmp;
580 		lwkt_reltoken(&p->p_token);
581 		PRELE(p);
582 		lwkt_reltoken(&proc_token);
583 		return (error);
584 
585 	case PT_IO:
586 		/*
587 		 * NOTE! uio_offset represents the offset in the target
588 		 * process.  The iov is in the current process (the guy
589 		 * making the ptrace call) so uio_td must be the current
590 		 * process.
591 		 */
592 		piod = addr;
593 		iov.iov_base = piod->piod_addr;
594 		iov.iov_len = piod->piod_len;
595 		uio.uio_iov = &iov;
596 		uio.uio_iovcnt = 1;
597 		uio.uio_offset = (off_t)(uintptr_t)piod->piod_offs;
598 		uio.uio_resid = piod->piod_len;
599 		uio.uio_segflg = UIO_USERSPACE;
600 		uio.uio_td = curthread;
601 		switch (piod->piod_op) {
602 		case PIOD_READ_D:
603 		case PIOD_READ_I:
604 			uio.uio_rw = UIO_READ;
605 			break;
606 		case PIOD_WRITE_D:
607 		case PIOD_WRITE_I:
608 			uio.uio_rw = UIO_WRITE;
609 			break;
610 		default:
611 			lwkt_reltoken(&p->p_token);
612 			PRELE(p);
613 			lwkt_reltoken(&proc_token);
614 			return (EINVAL);
615 		}
616 		error = procfs_domem(curp, lp, NULL, &uio);
617 		piod->piod_len -= uio.uio_resid;
618 		lwkt_reltoken(&p->p_token);
619 		PRELE(p);
620 		lwkt_reltoken(&proc_token);
621 		return (error);
622 
623 	case PT_KILL:
624 		data = SIGKILL;
625 		goto sendsig;	/* in PT_CONTINUE above */
626 
627 #ifdef PT_SETREGS
628 	case PT_SETREGS:
629 		write = 1;
630 		/* fallthrough */
631 #endif /* PT_SETREGS */
632 #ifdef PT_GETREGS
633 	case PT_GETREGS:
634 		/* write = 0 above */
635 #endif /* PT_SETREGS */
636 #if defined(PT_SETREGS) || defined(PT_GETREGS)
637 		if (!procfs_validregs(lp)) {	/* no P_SYSTEM procs please */
638 			lwkt_reltoken(&p->p_token);
639 			PRELE(p);
640 			lwkt_reltoken(&proc_token);
641 			return EINVAL;
642 		} else {
643 			iov.iov_base = addr;
644 			iov.iov_len = sizeof(struct reg);
645 			uio.uio_iov = &iov;
646 			uio.uio_iovcnt = 1;
647 			uio.uio_offset = 0;
648 			uio.uio_resid = sizeof(struct reg);
649 			uio.uio_segflg = UIO_SYSSPACE;
650 			uio.uio_rw = write ? UIO_WRITE : UIO_READ;
651 			uio.uio_td = curthread;
652 			t = procfs_doregs(curp, lp, NULL, &uio);
653 			lwkt_reltoken(&p->p_token);
654 			PRELE(p);
655 			lwkt_reltoken(&proc_token);
656 			return t;
657 		}
658 #endif /* defined(PT_SETREGS) || defined(PT_GETREGS) */
659 
660 #ifdef PT_SETFPREGS
661 	case PT_SETFPREGS:
662 		write = 1;
663 		/* fallthrough */
664 #endif /* PT_SETFPREGS */
665 #ifdef PT_GETFPREGS
666 	case PT_GETFPREGS:
667 		/* write = 0 above */
668 #endif /* PT_SETFPREGS */
669 #if defined(PT_SETFPREGS) || defined(PT_GETFPREGS)
670 		if (!procfs_validfpregs(lp)) {	/* no P_SYSTEM procs please */
671 			lwkt_reltoken(&p->p_token);
672 			PRELE(p);
673 			lwkt_reltoken(&proc_token);
674 			return EINVAL;
675 		} else {
676 			iov.iov_base = addr;
677 			iov.iov_len = sizeof(struct fpreg);
678 			uio.uio_iov = &iov;
679 			uio.uio_iovcnt = 1;
680 			uio.uio_offset = 0;
681 			uio.uio_resid = sizeof(struct fpreg);
682 			uio.uio_segflg = UIO_SYSSPACE;
683 			uio.uio_rw = write ? UIO_WRITE : UIO_READ;
684 			uio.uio_td = curthread;
685 			t = procfs_dofpregs(curp, lp, NULL, &uio);
686 			lwkt_reltoken(&p->p_token);
687 			PRELE(p);
688 			lwkt_reltoken(&proc_token);
689 			return t;
690 		}
691 #endif /* defined(PT_SETFPREGS) || defined(PT_GETFPREGS) */
692 
693 #ifdef PT_SETDBREGS
694 	case PT_SETDBREGS:
695 		write = 1;
696 		/* fallthrough */
697 #endif /* PT_SETDBREGS */
698 #ifdef PT_GETDBREGS
699 	case PT_GETDBREGS:
700 		/* write = 0 above */
701 #endif /* PT_SETDBREGS */
702 #if defined(PT_SETDBREGS) || defined(PT_GETDBREGS)
703 		if (!procfs_validdbregs(lp)) {	/* no P_SYSTEM procs please */
704 			lwkt_reltoken(&p->p_token);
705 			PRELE(p);
706 			lwkt_reltoken(&proc_token);
707 			return EINVAL;
708 		} else {
709 			iov.iov_base = addr;
710 			iov.iov_len = sizeof(struct dbreg);
711 			uio.uio_iov = &iov;
712 			uio.uio_iovcnt = 1;
713 			uio.uio_offset = 0;
714 			uio.uio_resid = sizeof(struct dbreg);
715 			uio.uio_segflg = UIO_SYSSPACE;
716 			uio.uio_rw = write ? UIO_WRITE : UIO_READ;
717 			uio.uio_td = curthread;
718 			t = procfs_dodbregs(curp, lp, NULL, &uio);
719 			lwkt_reltoken(&p->p_token);
720 			PRELE(p);
721 			lwkt_reltoken(&proc_token);
722 			return t;
723 		}
724 #endif /* defined(PT_SETDBREGS) || defined(PT_GETDBREGS) */
725 
726 	default:
727 		break;
728 	}
729 
730 	lwkt_reltoken(&p->p_token);
731 	PRELE(p);
732 	lwkt_reltoken(&proc_token);
733 
734 	return 0;
735 }
736 
737 int
738 trace_req(struct proc *p)
739 {
740 	return 1;
741 }
742 
743 /*
744  * stopevent()
745  *
746  * Stop a process because of a procfs event.  Stay stopped until p->p_step
747  * is cleared (cleared by PIOCCONT in procfs).
748  *
749  * MPSAFE
750  */
751 void
752 stopevent(struct proc *p, unsigned int event, unsigned int val)
753 {
754 	/*
755 	 * Set event info.  Recheck p_stops in case we are
756 	 * racing a close() on procfs.
757 	 */
758 	spin_lock(&p->p_spin);
759 	if ((p->p_stops & event) == 0) {
760 		spin_unlock(&p->p_spin);
761 		return;
762 	}
763 	p->p_xstat = val;
764 	p->p_stype = event;
765 	p->p_step = 1;
766 	tsleep_interlock(&p->p_step, 0);
767 	spin_unlock(&p->p_spin);
768 
769 	/*
770 	 * Wakeup any PIOCWAITing procs and wait for p_step to
771 	 * be cleared.
772 	 */
773 	for (;;) {
774 		wakeup(&p->p_stype);
775 		tsleep(&p->p_step, PINTERLOCKED, "stopevent", 0);
776 		spin_lock(&p->p_spin);
777 		if (p->p_step == 0) {
778 			spin_unlock(&p->p_spin);
779 			break;
780 		}
781 		tsleep_interlock(&p->p_step, 0);
782 		spin_unlock(&p->p_spin);
783 	}
784 }
785 
786