1 /*-
2 * Copyright (c) 1994, Sean Eric Fagan
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 * must display the following acknowledgement:
15 * This product includes software developed by Sean Eric Fagan.
16 * 4. The name of the author may not be used to endorse or promote products
17 * derived from this software without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32 #include <sys/cdefs.h>
33 __FBSDID("$FreeBSD$");
34
35 #include "opt_compat.h"
36 #include "opt_compat_mach.h"
37
38 #include <sys/param.h>
39 #include <sys/systm.h>
40 #include <sys/lock.h>
41 #include <sys/mutex.h>
42 #include <sys/syscallsubr.h>
43 #include <sys/sysent.h>
44 #include <sys/sysproto.h>
45 #include <sys/priv.h>
46 #include <sys/proc.h>
47 #include <sys/vnode.h>
48 #include <sys/ptrace.h>
49 #include <sys/rwlock.h>
50 #include <sys/sx.h>
51 #include <sys/malloc.h>
52 #include <sys/signalvar.h>
53
54 #include <machine/reg.h>
55
56 #include <security/audit/audit.h>
57
58 #include <vm/vm.h>
59 #include <vm/pmap.h>
60 #include <vm/vm_extern.h>
61 #include <vm/vm_map.h>
62 #include <vm/vm_kern.h>
63 #include <vm/vm_object.h>
64 #include <vm/vm_page.h>
65 #include <vm/vm_param.h>
66
67 #ifdef COMPAT_FREEBSD32
68 #include <sys/procfs.h>
69 #include <compat/freebsd32/freebsd32_signal.h>
70
71 struct ptrace_io_desc32 {
72 int piod_op;
73 uint32_t piod_offs;
74 uint32_t piod_addr;
75 uint32_t piod_len;
76 };
77
78 struct ptrace_vm_entry32 {
79 int pve_entry;
80 int pve_timestamp;
81 uint32_t pve_start;
82 uint32_t pve_end;
83 uint32_t pve_offset;
84 u_int pve_prot;
85 u_int pve_pathlen;
86 int32_t pve_fileid;
87 u_int pve_fsid;
88 uint32_t pve_path;
89 };
90
91 struct ptrace_lwpinfo32 {
92 lwpid_t pl_lwpid; /* LWP described. */
93 int pl_event; /* Event that stopped the LWP. */
94 int pl_flags; /* LWP flags. */
95 sigset_t pl_sigmask; /* LWP signal mask */
96 sigset_t pl_siglist; /* LWP pending signal */
97 struct siginfo32 pl_siginfo; /* siginfo for signal */
98 char pl_tdname[MAXCOMLEN + 1]; /* LWP name. */
99 int pl_child_pid; /* New child pid */
100 };
101
102 #endif
103
104 /*
105 * Functions implemented using PROC_ACTION():
106 *
107 * proc_read_regs(proc, regs)
108 * Get the current user-visible register set from the process
109 * and copy it into the regs structure (<machine/reg.h>).
110 * The process is stopped at the time read_regs is called.
111 *
112 * proc_write_regs(proc, regs)
113 * Update the current register set from the passed in regs
114 * structure. Take care to avoid clobbering special CPU
115 * registers or privileged bits in the PSL.
116 * Depending on the architecture this may have fix-up work to do,
117 * especially if the IAR or PCW are modified.
118 * The process is stopped at the time write_regs is called.
119 *
120 * proc_read_fpregs, proc_write_fpregs
121 * deal with the floating point register set, otherwise as above.
122 *
123 * proc_read_dbregs, proc_write_dbregs
124 * deal with the processor debug register set, otherwise as above.
125 *
126 * proc_sstep(proc)
127 * Arrange for the process to trap after executing a single instruction.
128 */
129
130 #define PROC_ACTION(action) do { \
131 int error; \
132 \
133 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED); \
134 if ((td->td_proc->p_flag & P_INMEM) == 0) \
135 error = EIO; \
136 else \
137 error = (action); \
138 return (error); \
139 } while(0)
140
141 int
proc_read_regs(struct thread * td,struct reg * regs)142 proc_read_regs(struct thread *td, struct reg *regs)
143 {
144
145 PROC_ACTION(fill_regs(td, regs));
146 }
147
148 int
proc_write_regs(struct thread * td,struct reg * regs)149 proc_write_regs(struct thread *td, struct reg *regs)
150 {
151
152 PROC_ACTION(set_regs(td, regs));
153 }
154
155 int
proc_read_dbregs(struct thread * td,struct dbreg * dbregs)156 proc_read_dbregs(struct thread *td, struct dbreg *dbregs)
157 {
158
159 PROC_ACTION(fill_dbregs(td, dbregs));
160 }
161
162 int
proc_write_dbregs(struct thread * td,struct dbreg * dbregs)163 proc_write_dbregs(struct thread *td, struct dbreg *dbregs)
164 {
165
166 PROC_ACTION(set_dbregs(td, dbregs));
167 }
168
169 /*
170 * Ptrace doesn't support fpregs at all, and there are no security holes
171 * or translations for fpregs, so we can just copy them.
172 */
173 int
proc_read_fpregs(struct thread * td,struct fpreg * fpregs)174 proc_read_fpregs(struct thread *td, struct fpreg *fpregs)
175 {
176
177 PROC_ACTION(fill_fpregs(td, fpregs));
178 }
179
180 int
proc_write_fpregs(struct thread * td,struct fpreg * fpregs)181 proc_write_fpregs(struct thread *td, struct fpreg *fpregs)
182 {
183
184 PROC_ACTION(set_fpregs(td, fpregs));
185 }
186
187 #ifdef COMPAT_FREEBSD32
188 /* For 32 bit binaries, we need to expose the 32 bit regs layouts. */
189 int
proc_read_regs32(struct thread * td,struct reg32 * regs32)190 proc_read_regs32(struct thread *td, struct reg32 *regs32)
191 {
192
193 PROC_ACTION(fill_regs32(td, regs32));
194 }
195
196 int
proc_write_regs32(struct thread * td,struct reg32 * regs32)197 proc_write_regs32(struct thread *td, struct reg32 *regs32)
198 {
199
200 PROC_ACTION(set_regs32(td, regs32));
201 }
202
203 int
proc_read_dbregs32(struct thread * td,struct dbreg32 * dbregs32)204 proc_read_dbregs32(struct thread *td, struct dbreg32 *dbregs32)
205 {
206
207 PROC_ACTION(fill_dbregs32(td, dbregs32));
208 }
209
210 int
proc_write_dbregs32(struct thread * td,struct dbreg32 * dbregs32)211 proc_write_dbregs32(struct thread *td, struct dbreg32 *dbregs32)
212 {
213
214 PROC_ACTION(set_dbregs32(td, dbregs32));
215 }
216
217 int
proc_read_fpregs32(struct thread * td,struct fpreg32 * fpregs32)218 proc_read_fpregs32(struct thread *td, struct fpreg32 *fpregs32)
219 {
220
221 PROC_ACTION(fill_fpregs32(td, fpregs32));
222 }
223
224 int
proc_write_fpregs32(struct thread * td,struct fpreg32 * fpregs32)225 proc_write_fpregs32(struct thread *td, struct fpreg32 *fpregs32)
226 {
227
228 PROC_ACTION(set_fpregs32(td, fpregs32));
229 }
230 #endif
231
232 int
proc_sstep(struct thread * td)233 proc_sstep(struct thread *td)
234 {
235
236 PROC_ACTION(ptrace_single_step(td));
237 }
238
239 int
proc_rwmem(struct proc * p,struct uio * uio)240 proc_rwmem(struct proc *p, struct uio *uio)
241 {
242 vm_map_t map;
243 vm_offset_t pageno; /* page number */
244 vm_prot_t reqprot;
245 int error, fault_flags, page_offset, writing;
246
247 /*
248 * Assert that someone has locked this vmspace. (Should be
249 * curthread but we can't assert that.) This keeps the process
250 * from exiting out from under us until this operation completes.
251 */
252 KASSERT(p->p_lock >= 1, ("%s: process %p (pid %d) not held", __func__,
253 p, p->p_pid));
254
255 /*
256 * The map we want...
257 */
258 map = &p->p_vmspace->vm_map;
259
260 /*
261 * If we are writing, then we request vm_fault() to create a private
262 * copy of each page. Since these copies will not be writeable by the
263 * process, we must explicity request that they be dirtied.
264 */
265 writing = uio->uio_rw == UIO_WRITE;
266 reqprot = writing ? VM_PROT_COPY | VM_PROT_READ : VM_PROT_READ;
267 fault_flags = writing ? VM_FAULT_DIRTY : VM_FAULT_NORMAL;
268
269 /*
270 * Only map in one page at a time. We don't have to, but it
271 * makes things easier. This way is trivial - right?
272 */
273 do {
274 vm_offset_t uva;
275 u_int len;
276 vm_page_t m;
277
278 uva = (vm_offset_t)uio->uio_offset;
279
280 /*
281 * Get the page number of this segment.
282 */
283 pageno = trunc_page(uva);
284 page_offset = uva - pageno;
285
286 /*
287 * How many bytes to copy
288 */
289 len = min(PAGE_SIZE - page_offset, uio->uio_resid);
290
291 /*
292 * Fault and hold the page on behalf of the process.
293 */
294 error = vm_fault_hold(map, pageno, reqprot, fault_flags, &m);
295 if (error != KERN_SUCCESS) {
296 if (error == KERN_RESOURCE_SHORTAGE)
297 error = ENOMEM;
298 else
299 error = EFAULT;
300 break;
301 }
302
303 /*
304 * Now do the i/o move.
305 */
306 error = uiomove_fromphys(&m, page_offset, len, uio);
307
308 /* Make the I-cache coherent for breakpoints. */
309 if (writing && error == 0) {
310 vm_map_lock_read(map);
311 if (vm_map_check_protection(map, pageno, pageno +
312 PAGE_SIZE, VM_PROT_EXECUTE))
313 vm_sync_icache(map, uva, len);
314 vm_map_unlock_read(map);
315 }
316
317 /*
318 * Release the page.
319 */
320 vm_page_lock(m);
321 vm_page_unhold(m);
322 vm_page_unlock(m);
323
324 } while (error == 0 && uio->uio_resid > 0);
325
326 return (error);
327 }
328
329 static int
ptrace_vm_entry(struct thread * td,struct proc * p,struct ptrace_vm_entry * pve)330 ptrace_vm_entry(struct thread *td, struct proc *p, struct ptrace_vm_entry *pve)
331 {
332 struct vattr vattr;
333 vm_map_t map;
334 vm_map_entry_t entry;
335 vm_object_t obj, tobj, lobj;
336 struct vmspace *vm;
337 struct vnode *vp;
338 char *freepath, *fullpath;
339 u_int pathlen;
340 int error, index;
341
342 error = 0;
343 obj = NULL;
344
345 vm = vmspace_acquire_ref(p);
346 map = &vm->vm_map;
347 vm_map_lock_read(map);
348
349 do {
350 entry = map->header.next;
351 index = 0;
352 while (index < pve->pve_entry && entry != &map->header) {
353 entry = entry->next;
354 index++;
355 }
356 if (index != pve->pve_entry) {
357 error = EINVAL;
358 break;
359 }
360 while (entry != &map->header &&
361 (entry->eflags & MAP_ENTRY_IS_SUB_MAP) != 0) {
362 entry = entry->next;
363 index++;
364 }
365 if (entry == &map->header) {
366 error = ENOENT;
367 break;
368 }
369
370 /* We got an entry. */
371 pve->pve_entry = index + 1;
372 pve->pve_timestamp = map->timestamp;
373 pve->pve_start = entry->start;
374 pve->pve_end = entry->end - 1;
375 pve->pve_offset = entry->offset;
376 pve->pve_prot = entry->protection;
377
378 /* Backing object's path needed? */
379 if (pve->pve_pathlen == 0)
380 break;
381
382 pathlen = pve->pve_pathlen;
383 pve->pve_pathlen = 0;
384
385 obj = entry->object.vm_object;
386 if (obj != NULL)
387 VM_OBJECT_RLOCK(obj);
388 } while (0);
389
390 vm_map_unlock_read(map);
391 vmspace_free(vm);
392
393 pve->pve_fsid = VNOVAL;
394 pve->pve_fileid = VNOVAL;
395
396 if (error == 0 && obj != NULL) {
397 lobj = obj;
398 for (tobj = obj; tobj != NULL; tobj = tobj->backing_object) {
399 if (tobj != obj)
400 VM_OBJECT_RLOCK(tobj);
401 if (lobj != obj)
402 VM_OBJECT_RUNLOCK(lobj);
403 lobj = tobj;
404 pve->pve_offset += tobj->backing_object_offset;
405 }
406 vp = (lobj->type == OBJT_VNODE) ? lobj->handle : NULL;
407 if (vp != NULL)
408 vref(vp);
409 if (lobj != obj)
410 VM_OBJECT_RUNLOCK(lobj);
411 VM_OBJECT_RUNLOCK(obj);
412
413 if (vp != NULL) {
414 freepath = NULL;
415 fullpath = NULL;
416 vn_fullpath(td, vp, &fullpath, &freepath);
417 vn_lock(vp, LK_SHARED | LK_RETRY);
418 if (VOP_GETATTR(vp, &vattr, td->td_ucred) == 0) {
419 pve->pve_fileid = vattr.va_fileid;
420 pve->pve_fsid = vattr.va_fsid;
421 }
422 vput(vp);
423
424 if (fullpath != NULL) {
425 pve->pve_pathlen = strlen(fullpath) + 1;
426 if (pve->pve_pathlen <= pathlen) {
427 error = copyout(fullpath, pve->pve_path,
428 pve->pve_pathlen);
429 } else
430 error = ENAMETOOLONG;
431 }
432 if (freepath != NULL)
433 free(freepath, M_TEMP);
434 }
435 }
436
437 return (error);
438 }
439
440 #ifdef COMPAT_FREEBSD32
441 static int
ptrace_vm_entry32(struct thread * td,struct proc * p,struct ptrace_vm_entry32 * pve32)442 ptrace_vm_entry32(struct thread *td, struct proc *p,
443 struct ptrace_vm_entry32 *pve32)
444 {
445 struct ptrace_vm_entry pve;
446 int error;
447
448 pve.pve_entry = pve32->pve_entry;
449 pve.pve_pathlen = pve32->pve_pathlen;
450 pve.pve_path = (void *)(uintptr_t)pve32->pve_path;
451
452 error = ptrace_vm_entry(td, p, &pve);
453 if (error == 0) {
454 pve32->pve_entry = pve.pve_entry;
455 pve32->pve_timestamp = pve.pve_timestamp;
456 pve32->pve_start = pve.pve_start;
457 pve32->pve_end = pve.pve_end;
458 pve32->pve_offset = pve.pve_offset;
459 pve32->pve_prot = pve.pve_prot;
460 pve32->pve_fileid = pve.pve_fileid;
461 pve32->pve_fsid = pve.pve_fsid;
462 }
463
464 pve32->pve_pathlen = pve.pve_pathlen;
465 return (error);
466 }
467
468 static void
ptrace_lwpinfo_to32(const struct ptrace_lwpinfo * pl,struct ptrace_lwpinfo32 * pl32)469 ptrace_lwpinfo_to32(const struct ptrace_lwpinfo *pl,
470 struct ptrace_lwpinfo32 *pl32)
471 {
472
473 pl32->pl_lwpid = pl->pl_lwpid;
474 pl32->pl_event = pl->pl_event;
475 pl32->pl_flags = pl->pl_flags;
476 pl32->pl_sigmask = pl->pl_sigmask;
477 pl32->pl_siglist = pl->pl_siglist;
478 siginfo_to_siginfo32(&pl->pl_siginfo, &pl32->pl_siginfo);
479 strcpy(pl32->pl_tdname, pl->pl_tdname);
480 pl32->pl_child_pid = pl->pl_child_pid;
481 }
482 #endif /* COMPAT_FREEBSD32 */
483
484 /*
485 * Process debugging system call.
486 */
487 #ifndef _SYS_SYSPROTO_H_
488 struct ptrace_args {
489 int req;
490 pid_t pid;
491 caddr_t addr;
492 int data;
493 };
494 #endif
495
496 #ifdef COMPAT_FREEBSD32
497 /*
498 * This CPP subterfuge is to try and reduce the number of ifdefs in
499 * the body of the code.
500 * COPYIN(uap->addr, &r.reg, sizeof r.reg);
501 * becomes either:
502 * copyin(uap->addr, &r.reg, sizeof r.reg);
503 * or
504 * copyin(uap->addr, &r.reg32, sizeof r.reg32);
505 * .. except this is done at runtime.
506 */
507 #define COPYIN(u, k, s) wrap32 ? \
508 copyin(u, k ## 32, s ## 32) : \
509 copyin(u, k, s)
510 #define COPYOUT(k, u, s) wrap32 ? \
511 copyout(k ## 32, u, s ## 32) : \
512 copyout(k, u, s)
513 #else
514 #define COPYIN(u, k, s) copyin(u, k, s)
515 #define COPYOUT(k, u, s) copyout(k, u, s)
516 #endif
517 int
sys_ptrace(struct thread * td,struct ptrace_args * uap)518 sys_ptrace(struct thread *td, struct ptrace_args *uap)
519 {
520 /*
521 * XXX this obfuscation is to reduce stack usage, but the register
522 * structs may be too large to put on the stack anyway.
523 */
524 union {
525 struct ptrace_io_desc piod;
526 struct ptrace_lwpinfo pl;
527 struct ptrace_vm_entry pve;
528 struct dbreg dbreg;
529 struct fpreg fpreg;
530 struct reg reg;
531 #ifdef COMPAT_FREEBSD32
532 struct dbreg32 dbreg32;
533 struct fpreg32 fpreg32;
534 struct reg32 reg32;
535 struct ptrace_io_desc32 piod32;
536 struct ptrace_lwpinfo32 pl32;
537 struct ptrace_vm_entry32 pve32;
538 #endif
539 } r;
540 void *addr;
541 int error = 0;
542 #ifdef COMPAT_FREEBSD32
543 int wrap32 = 0;
544
545 if (SV_CURPROC_FLAG(SV_ILP32))
546 wrap32 = 1;
547 #endif
548 AUDIT_ARG_PID(uap->pid);
549 AUDIT_ARG_CMD(uap->req);
550 AUDIT_ARG_VALUE(uap->data);
551 addr = &r;
552 switch (uap->req) {
553 case PT_GETREGS:
554 case PT_GETFPREGS:
555 case PT_GETDBREGS:
556 case PT_LWPINFO:
557 break;
558 case PT_SETREGS:
559 error = COPYIN(uap->addr, &r.reg, sizeof r.reg);
560 break;
561 case PT_SETFPREGS:
562 error = COPYIN(uap->addr, &r.fpreg, sizeof r.fpreg);
563 break;
564 case PT_SETDBREGS:
565 error = COPYIN(uap->addr, &r.dbreg, sizeof r.dbreg);
566 break;
567 case PT_IO:
568 error = COPYIN(uap->addr, &r.piod, sizeof r.piod);
569 break;
570 case PT_VM_ENTRY:
571 error = COPYIN(uap->addr, &r.pve, sizeof r.pve);
572 break;
573 default:
574 addr = uap->addr;
575 break;
576 }
577 if (error)
578 return (error);
579
580 error = kern_ptrace(td, uap->req, uap->pid, addr, uap->data);
581 if (error)
582 return (error);
583
584 switch (uap->req) {
585 case PT_VM_ENTRY:
586 error = COPYOUT(&r.pve, uap->addr, sizeof r.pve);
587 break;
588 case PT_IO:
589 error = COPYOUT(&r.piod, uap->addr, sizeof r.piod);
590 break;
591 case PT_GETREGS:
592 error = COPYOUT(&r.reg, uap->addr, sizeof r.reg);
593 break;
594 case PT_GETFPREGS:
595 error = COPYOUT(&r.fpreg, uap->addr, sizeof r.fpreg);
596 break;
597 case PT_GETDBREGS:
598 error = COPYOUT(&r.dbreg, uap->addr, sizeof r.dbreg);
599 break;
600 case PT_LWPINFO:
601 error = copyout(&r.pl, uap->addr, uap->data);
602 break;
603 }
604
605 return (error);
606 }
607 #undef COPYIN
608 #undef COPYOUT
609
610 #ifdef COMPAT_FREEBSD32
611 /*
612 * PROC_READ(regs, td2, addr);
613 * becomes either:
614 * proc_read_regs(td2, addr);
615 * or
616 * proc_read_regs32(td2, addr);
617 * .. except this is done at runtime. There is an additional
618 * complication in that PROC_WRITE disallows 32 bit consumers
619 * from writing to 64 bit address space targets.
620 */
621 #define PROC_READ(w, t, a) wrap32 ? \
622 proc_read_ ## w ## 32(t, a) : \
623 proc_read_ ## w (t, a)
624 #define PROC_WRITE(w, t, a) wrap32 ? \
625 (safe ? proc_write_ ## w ## 32(t, a) : EINVAL ) : \
626 proc_write_ ## w (t, a)
627 #else
628 #define PROC_READ(w, t, a) proc_read_ ## w (t, a)
629 #define PROC_WRITE(w, t, a) proc_write_ ## w (t, a)
630 #endif
631
632 int
kern_ptrace(struct thread * td,int req,pid_t pid,void * addr,int data)633 kern_ptrace(struct thread *td, int req, pid_t pid, void *addr, int data)
634 {
635 struct iovec iov;
636 struct uio uio;
637 struct proc *curp, *p, *pp;
638 struct thread *td2 = NULL, *td3;
639 struct ptrace_io_desc *piod = NULL;
640 struct ptrace_lwpinfo *pl;
641 int error, write, tmp, num;
642 int proctree_locked = 0;
643 lwpid_t tid = 0, *buf;
644 #ifdef COMPAT_FREEBSD32
645 int wrap32 = 0, safe = 0;
646 struct ptrace_io_desc32 *piod32 = NULL;
647 struct ptrace_lwpinfo32 *pl32 = NULL;
648 struct ptrace_lwpinfo plr;
649 #endif
650
651 curp = td->td_proc;
652
653 /* Lock proctree before locking the process. */
654 switch (req) {
655 case PT_TRACE_ME:
656 case PT_ATTACH:
657 case PT_STEP:
658 case PT_CONTINUE:
659 case PT_TO_SCE:
660 case PT_TO_SCX:
661 case PT_SYSCALL:
662 case PT_FOLLOW_FORK:
663 case PT_DETACH:
664 sx_xlock(&proctree_lock);
665 proctree_locked = 1;
666 break;
667 default:
668 break;
669 }
670
671 write = 0;
672 if (req == PT_TRACE_ME) {
673 p = td->td_proc;
674 PROC_LOCK(p);
675 } else {
676 if (pid <= PID_MAX) {
677 if ((p = pfind(pid)) == NULL) {
678 if (proctree_locked)
679 sx_xunlock(&proctree_lock);
680 return (ESRCH);
681 }
682 } else {
683 td2 = tdfind(pid, -1);
684 if (td2 == NULL) {
685 if (proctree_locked)
686 sx_xunlock(&proctree_lock);
687 return (ESRCH);
688 }
689 p = td2->td_proc;
690 tid = pid;
691 pid = p->p_pid;
692 }
693 }
694 AUDIT_ARG_PROCESS(p);
695
696 if ((p->p_flag & P_WEXIT) != 0) {
697 error = ESRCH;
698 goto fail;
699 }
700 if ((error = p_cansee(td, p)) != 0)
701 goto fail;
702
703 if ((error = p_candebug(td, p)) != 0)
704 goto fail;
705
706 /*
707 * System processes can't be debugged.
708 */
709 if ((p->p_flag & P_SYSTEM) != 0) {
710 error = EINVAL;
711 goto fail;
712 }
713
714 if (tid == 0) {
715 if ((p->p_flag & P_STOPPED_TRACE) != 0) {
716 KASSERT(p->p_xthread != NULL, ("NULL p_xthread"));
717 td2 = p->p_xthread;
718 } else {
719 td2 = FIRST_THREAD_IN_PROC(p);
720 }
721 tid = td2->td_tid;
722 }
723
724 #ifdef COMPAT_FREEBSD32
725 /*
726 * Test if we're a 32 bit client and what the target is.
727 * Set the wrap controls accordingly.
728 */
729 if (SV_CURPROC_FLAG(SV_ILP32)) {
730 if (SV_PROC_FLAG(td2->td_proc, SV_ILP32))
731 safe = 1;
732 wrap32 = 1;
733 }
734 #endif
735 /*
736 * Permissions check
737 */
738 switch (req) {
739 case PT_TRACE_ME:
740 /* Always legal. */
741 break;
742
743 case PT_ATTACH:
744 /* Self */
745 if (p->p_pid == td->td_proc->p_pid) {
746 error = EINVAL;
747 goto fail;
748 }
749
750 /* Already traced */
751 if (p->p_flag & P_TRACED) {
752 error = EBUSY;
753 goto fail;
754 }
755
756 /* Can't trace an ancestor if you're being traced. */
757 if (curp->p_flag & P_TRACED) {
758 for (pp = curp->p_pptr; pp != NULL; pp = pp->p_pptr) {
759 if (pp == p) {
760 error = EINVAL;
761 goto fail;
762 }
763 }
764 }
765
766
767 /* OK */
768 break;
769
770 case PT_CLEARSTEP:
771 /* Allow thread to clear single step for itself */
772 if (td->td_tid == tid)
773 break;
774
775 /* FALLTHROUGH */
776 default:
777 /* not being traced... */
778 if ((p->p_flag & P_TRACED) == 0) {
779 error = EPERM;
780 goto fail;
781 }
782
783 /* not being traced by YOU */
784 if (p->p_pptr != td->td_proc) {
785 error = EBUSY;
786 goto fail;
787 }
788
789 /* not currently stopped */
790 if ((p->p_flag & (P_STOPPED_SIG | P_STOPPED_TRACE)) == 0 ||
791 p->p_suspcount != p->p_numthreads ||
792 (p->p_flag & P_WAITED) == 0) {
793 error = EBUSY;
794 goto fail;
795 }
796
797 if ((p->p_flag & P_STOPPED_TRACE) == 0) {
798 static int count = 0;
799 if (count++ == 0)
800 printf("P_STOPPED_TRACE not set.\n");
801 }
802
803 /* OK */
804 break;
805 }
806
807 /* Keep this process around until we finish this request. */
808 _PHOLD(p);
809
810 #ifdef FIX_SSTEP
811 /*
812 * Single step fixup ala procfs
813 */
814 FIX_SSTEP(td2);
815 #endif
816
817 /*
818 * Actually do the requests
819 */
820
821 td->td_retval[0] = 0;
822
823 switch (req) {
824 case PT_TRACE_ME:
825 /* set my trace flag and "owner" so it can read/write me */
826 p->p_flag |= P_TRACED;
827 if (p->p_flag & P_PPWAIT)
828 p->p_flag |= P_PPTRACE;
829 p->p_oppid = p->p_pptr->p_pid;
830 break;
831
832 case PT_ATTACH:
833 /* security check done above */
834 /*
835 * It would be nice if the tracing relationship was separate
836 * from the parent relationship but that would require
837 * another set of links in the proc struct or for "wait"
838 * to scan the entire proc table. To make life easier,
839 * we just re-parent the process we're trying to trace.
840 * The old parent is remembered so we can put things back
841 * on a "detach".
842 */
843 p->p_flag |= P_TRACED;
844 p->p_oppid = p->p_pptr->p_pid;
845 if (p->p_pptr != td->td_proc) {
846 proc_reparent(p, td->td_proc);
847 }
848 data = SIGSTOP;
849 goto sendsig; /* in PT_CONTINUE below */
850
851 case PT_CLEARSTEP:
852 error = ptrace_clear_single_step(td2);
853 break;
854
855 case PT_SETSTEP:
856 error = ptrace_single_step(td2);
857 break;
858
859 case PT_SUSPEND:
860 td2->td_dbgflags |= TDB_SUSPEND;
861 thread_lock(td2);
862 td2->td_flags |= TDF_NEEDSUSPCHK;
863 thread_unlock(td2);
864 break;
865
866 case PT_RESUME:
867 td2->td_dbgflags &= ~TDB_SUSPEND;
868 break;
869
870 case PT_FOLLOW_FORK:
871 if (data)
872 p->p_flag |= P_FOLLOWFORK;
873 else
874 p->p_flag &= ~P_FOLLOWFORK;
875 break;
876
877 case PT_STEP:
878 case PT_CONTINUE:
879 case PT_TO_SCE:
880 case PT_TO_SCX:
881 case PT_SYSCALL:
882 case PT_DETACH:
883 /* Zero means do not send any signal */
884 if (data < 0 || data > _SIG_MAXSIG) {
885 error = EINVAL;
886 break;
887 }
888
889 switch (req) {
890 case PT_STEP:
891 error = ptrace_single_step(td2);
892 if (error)
893 goto out;
894 break;
895 case PT_CONTINUE:
896 case PT_TO_SCE:
897 case PT_TO_SCX:
898 case PT_SYSCALL:
899 if (addr != (void *)1) {
900 error = ptrace_set_pc(td2,
901 (u_long)(uintfptr_t)addr);
902 if (error)
903 goto out;
904 }
905 switch (req) {
906 case PT_TO_SCE:
907 p->p_stops |= S_PT_SCE;
908 break;
909 case PT_TO_SCX:
910 p->p_stops |= S_PT_SCX;
911 break;
912 case PT_SYSCALL:
913 p->p_stops |= S_PT_SCE | S_PT_SCX;
914 break;
915 }
916 break;
917 case PT_DETACH:
918 /* reset process parent */
919 if (p->p_oppid != p->p_pptr->p_pid) {
920 PROC_LOCK(p->p_pptr);
921 sigqueue_take(p->p_ksi);
922 PROC_UNLOCK(p->p_pptr);
923
924 pp = proc_realparent(p);
925 proc_reparent(p, pp);
926 if (pp == initproc)
927 p->p_sigparent = SIGCHLD;
928 }
929 p->p_oppid = 0;
930 p->p_flag &= ~(P_TRACED | P_WAITED | P_FOLLOWFORK);
931 p->p_stops = 0;
932
933 /* should we send SIGCHLD? */
934 /* childproc_continued(p); */
935 break;
936 }
937
938 sendsig:
939 if (proctree_locked) {
940 sx_xunlock(&proctree_lock);
941 proctree_locked = 0;
942 }
943 p->p_xstat = data;
944 p->p_xthread = NULL;
945 if ((p->p_flag & (P_STOPPED_SIG | P_STOPPED_TRACE)) != 0) {
946 /* deliver or queue signal */
947 td2->td_dbgflags &= ~TDB_XSIG;
948 td2->td_xsig = data;
949
950 if (req == PT_DETACH) {
951 FOREACH_THREAD_IN_PROC(p, td3)
952 td3->td_dbgflags &= ~TDB_SUSPEND;
953 }
954 /*
955 * unsuspend all threads, to not let a thread run,
956 * you should use PT_SUSPEND to suspend it before
957 * continuing process.
958 */
959 PROC_SLOCK(p);
960 p->p_flag &= ~(P_STOPPED_TRACE|P_STOPPED_SIG|P_WAITED);
961 thread_unsuspend(p);
962 PROC_SUNLOCK(p);
963 if (req == PT_ATTACH)
964 kern_psignal(p, data);
965 } else {
966 if (data)
967 kern_psignal(p, data);
968 }
969 break;
970
971 case PT_WRITE_I:
972 case PT_WRITE_D:
973 td2->td_dbgflags |= TDB_USERWR;
974 write = 1;
975 /* FALLTHROUGH */
976 case PT_READ_I:
977 case PT_READ_D:
978 PROC_UNLOCK(p);
979 tmp = 0;
980 /* write = 0 set above */
981 iov.iov_base = write ? (caddr_t)&data : (caddr_t)&tmp;
982 iov.iov_len = sizeof(int);
983 uio.uio_iov = &iov;
984 uio.uio_iovcnt = 1;
985 uio.uio_offset = (off_t)(uintptr_t)addr;
986 uio.uio_resid = sizeof(int);
987 uio.uio_segflg = UIO_SYSSPACE; /* i.e.: the uap */
988 uio.uio_rw = write ? UIO_WRITE : UIO_READ;
989 uio.uio_td = td;
990 error = proc_rwmem(p, &uio);
991 if (uio.uio_resid != 0) {
992 /*
993 * XXX proc_rwmem() doesn't currently return ENOSPC,
994 * so I think write() can bogusly return 0.
995 * XXX what happens for short writes? We don't want
996 * to write partial data.
997 * XXX proc_rwmem() returns EPERM for other invalid
998 * addresses. Convert this to EINVAL. Does this
999 * clobber returns of EPERM for other reasons?
1000 */
1001 if (error == 0 || error == ENOSPC || error == EPERM)
1002 error = EINVAL; /* EOF */
1003 }
1004 if (!write)
1005 td->td_retval[0] = tmp;
1006 PROC_LOCK(p);
1007 break;
1008
1009 case PT_IO:
1010 #ifdef COMPAT_FREEBSD32
1011 if (wrap32) {
1012 piod32 = addr;
1013 iov.iov_base = (void *)(uintptr_t)piod32->piod_addr;
1014 iov.iov_len = piod32->piod_len;
1015 uio.uio_offset = (off_t)(uintptr_t)piod32->piod_offs;
1016 uio.uio_resid = piod32->piod_len;
1017 } else
1018 #endif
1019 {
1020 piod = addr;
1021 iov.iov_base = piod->piod_addr;
1022 iov.iov_len = piod->piod_len;
1023 uio.uio_offset = (off_t)(uintptr_t)piod->piod_offs;
1024 uio.uio_resid = piod->piod_len;
1025 }
1026 uio.uio_iov = &iov;
1027 uio.uio_iovcnt = 1;
1028 uio.uio_segflg = UIO_USERSPACE;
1029 uio.uio_td = td;
1030 #ifdef COMPAT_FREEBSD32
1031 tmp = wrap32 ? piod32->piod_op : piod->piod_op;
1032 #else
1033 tmp = piod->piod_op;
1034 #endif
1035 switch (tmp) {
1036 case PIOD_READ_D:
1037 case PIOD_READ_I:
1038 uio.uio_rw = UIO_READ;
1039 break;
1040 case PIOD_WRITE_D:
1041 case PIOD_WRITE_I:
1042 td2->td_dbgflags |= TDB_USERWR;
1043 uio.uio_rw = UIO_WRITE;
1044 break;
1045 default:
1046 error = EINVAL;
1047 goto out;
1048 }
1049 PROC_UNLOCK(p);
1050 error = proc_rwmem(p, &uio);
1051 #ifdef COMPAT_FREEBSD32
1052 if (wrap32)
1053 piod32->piod_len -= uio.uio_resid;
1054 else
1055 #endif
1056 piod->piod_len -= uio.uio_resid;
1057 PROC_LOCK(p);
1058 break;
1059
1060 case PT_KILL:
1061 data = SIGKILL;
1062 goto sendsig; /* in PT_CONTINUE above */
1063
1064 case PT_SETREGS:
1065 td2->td_dbgflags |= TDB_USERWR;
1066 error = PROC_WRITE(regs, td2, addr);
1067 break;
1068
1069 case PT_GETREGS:
1070 error = PROC_READ(regs, td2, addr);
1071 break;
1072
1073 case PT_SETFPREGS:
1074 td2->td_dbgflags |= TDB_USERWR;
1075 error = PROC_WRITE(fpregs, td2, addr);
1076 break;
1077
1078 case PT_GETFPREGS:
1079 error = PROC_READ(fpregs, td2, addr);
1080 break;
1081
1082 case PT_SETDBREGS:
1083 td2->td_dbgflags |= TDB_USERWR;
1084 error = PROC_WRITE(dbregs, td2, addr);
1085 break;
1086
1087 case PT_GETDBREGS:
1088 error = PROC_READ(dbregs, td2, addr);
1089 break;
1090
1091 case PT_LWPINFO:
1092 if (data <= 0 ||
1093 #ifdef COMPAT_FREEBSD32
1094 (!wrap32 && data > sizeof(*pl)) ||
1095 (wrap32 && data > sizeof(*pl32))) {
1096 #else
1097 data > sizeof(*pl)) {
1098 #endif
1099 error = EINVAL;
1100 break;
1101 }
1102 #ifdef COMPAT_FREEBSD32
1103 if (wrap32) {
1104 pl = &plr;
1105 pl32 = addr;
1106 } else
1107 #endif
1108 pl = addr;
1109 pl->pl_lwpid = td2->td_tid;
1110 pl->pl_event = PL_EVENT_NONE;
1111 pl->pl_flags = 0;
1112 if (td2->td_dbgflags & TDB_XSIG) {
1113 pl->pl_event = PL_EVENT_SIGNAL;
1114 if (td2->td_dbgksi.ksi_signo != 0 &&
1115 #ifdef COMPAT_FREEBSD32
1116 ((!wrap32 && data >= offsetof(struct ptrace_lwpinfo,
1117 pl_siginfo) + sizeof(pl->pl_siginfo)) ||
1118 (wrap32 && data >= offsetof(struct ptrace_lwpinfo32,
1119 pl_siginfo) + sizeof(struct siginfo32)))
1120 #else
1121 data >= offsetof(struct ptrace_lwpinfo, pl_siginfo)
1122 + sizeof(pl->pl_siginfo)
1123 #endif
1124 ){
1125 pl->pl_flags |= PL_FLAG_SI;
1126 pl->pl_siginfo = td2->td_dbgksi.ksi_info;
1127 }
1128 }
1129 if ((pl->pl_flags & PL_FLAG_SI) == 0)
1130 bzero(&pl->pl_siginfo, sizeof(pl->pl_siginfo));
1131 if (td2->td_dbgflags & TDB_SCE)
1132 pl->pl_flags |= PL_FLAG_SCE;
1133 else if (td2->td_dbgflags & TDB_SCX)
1134 pl->pl_flags |= PL_FLAG_SCX;
1135 if (td2->td_dbgflags & TDB_EXEC)
1136 pl->pl_flags |= PL_FLAG_EXEC;
1137 if (td2->td_dbgflags & TDB_FORK) {
1138 pl->pl_flags |= PL_FLAG_FORKED;
1139 pl->pl_child_pid = td2->td_dbg_forked;
1140 }
1141 if (td2->td_dbgflags & TDB_CHILD)
1142 pl->pl_flags |= PL_FLAG_CHILD;
1143 pl->pl_sigmask = td2->td_sigmask;
1144 pl->pl_siglist = td2->td_siglist;
1145 strcpy(pl->pl_tdname, td2->td_name);
1146 #ifdef COMPAT_FREEBSD32
1147 if (wrap32)
1148 ptrace_lwpinfo_to32(pl, pl32);
1149 #endif
1150 break;
1151
1152 case PT_GETNUMLWPS:
1153 td->td_retval[0] = p->p_numthreads;
1154 break;
1155
1156 case PT_GETLWPLIST:
1157 if (data <= 0) {
1158 error = EINVAL;
1159 break;
1160 }
1161 num = imin(p->p_numthreads, data);
1162 PROC_UNLOCK(p);
1163 buf = malloc(num * sizeof(lwpid_t), M_TEMP, M_WAITOK);
1164 tmp = 0;
1165 PROC_LOCK(p);
1166 FOREACH_THREAD_IN_PROC(p, td2) {
1167 if (tmp >= num)
1168 break;
1169 buf[tmp++] = td2->td_tid;
1170 }
1171 PROC_UNLOCK(p);
1172 error = copyout(buf, addr, tmp * sizeof(lwpid_t));
1173 free(buf, M_TEMP);
1174 if (!error)
1175 td->td_retval[0] = tmp;
1176 PROC_LOCK(p);
1177 break;
1178
1179 case PT_VM_TIMESTAMP:
1180 td->td_retval[0] = p->p_vmspace->vm_map.timestamp;
1181 break;
1182
1183 case PT_VM_ENTRY:
1184 PROC_UNLOCK(p);
1185 #ifdef COMPAT_FREEBSD32
1186 if (wrap32)
1187 error = ptrace_vm_entry32(td, p, addr);
1188 else
1189 #endif
1190 error = ptrace_vm_entry(td, p, addr);
1191 PROC_LOCK(p);
1192 break;
1193
1194 default:
1195 #ifdef __HAVE_PTRACE_MACHDEP
1196 if (req >= PT_FIRSTMACH) {
1197 PROC_UNLOCK(p);
1198 error = cpu_ptrace(td2, req, addr, data);
1199 PROC_LOCK(p);
1200 } else
1201 #endif
1202 /* Unknown request. */
1203 error = EINVAL;
1204 break;
1205 }
1206
1207 out:
1208 /* Drop our hold on this process now that the request has completed. */
1209 _PRELE(p);
1210 fail:
1211 PROC_UNLOCK(p);
1212 if (proctree_locked)
1213 sx_xunlock(&proctree_lock);
1214 return (error);
1215 }
1216 #undef PROC_READ
1217 #undef PROC_WRITE
1218
1219 /*
1220 * Stop a process because of a debugging event;
1221 * stay stopped until p->p_step is cleared
1222 * (cleared by PIOCCONT in procfs).
1223 */
1224 void
1225 stopevent(struct proc *p, unsigned int event, unsigned int val)
1226 {
1227
1228 PROC_LOCK_ASSERT(p, MA_OWNED);
1229 p->p_step = 1;
1230 do {
1231 p->p_xstat = val;
1232 p->p_xthread = NULL;
1233 p->p_stype = event; /* Which event caused the stop? */
1234 wakeup(&p->p_stype); /* Wake up any PIOCWAIT'ing procs */
1235 msleep(&p->p_step, &p->p_mtx, PWAIT, "stopevent", 0);
1236 } while (p->p_step);
1237 }
1238
1239
1240