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Merge branch 'akpm-incoming-2'
[mirror_ubuntu-artful-kernel.git] / kernel / ptrace.c
CommitLineData
1da177e4
LT
1/*
2 * linux/kernel/ptrace.c
3 *
4 * (C) Copyright 1999 Linus Torvalds
5 *
6 * Common interfaces for "ptrace()" which we do not want
7 * to continually duplicate across every architecture.
8 */
9
c59ede7b 10#include <linux/capability.h>
1da177e4
LT
11#include <linux/module.h>
12#include <linux/sched.h>
13#include <linux/errno.h>
14#include <linux/mm.h>
15#include <linux/highmem.h>
16#include <linux/pagemap.h>
1da177e4
LT
17#include <linux/ptrace.h>
18#include <linux/security.h>
7ed20e1a 19#include <linux/signal.h>
a5cb013d 20#include <linux/audit.h>
b488893a 21#include <linux/pid_namespace.h>
f17d30a8 22#include <linux/syscalls.h>
3a709703 23#include <linux/uaccess.h>
2225a122 24#include <linux/regset.h>
1da177e4 25
bf53de90 26
1da177e4
LT
27/*
28 * ptrace a task: make the debugger its new parent and
29 * move it to the ptrace list.
30 *
31 * Must be called with the tasklist lock write-held.
32 */
36c8b586 33void __ptrace_link(struct task_struct *child, struct task_struct *new_parent)
1da177e4 34{
f470021a
RM
35 BUG_ON(!list_empty(&child->ptrace_entry));
36 list_add(&child->ptrace_entry, &new_parent->ptraced);
1da177e4 37 child->parent = new_parent;
1da177e4 38}
3a709703 39
1da177e4
LT
40/*
41 * Turn a tracing stop into a normal stop now, since with no tracer there
42 * would be no way to wake it up with SIGCONT or SIGKILL. If there was a
43 * signal sent that would resume the child, but didn't because it was in
44 * TASK_TRACED, resume it now.
45 * Requires that irqs be disabled.
46 */
b747c8c1 47static void ptrace_untrace(struct task_struct *child)
1da177e4
LT
48{
49 spin_lock(&child->sighand->siglock);
6618a3e2 50 if (task_is_traced(child)) {
1ee11844
ON
51 /*
52 * If the group stop is completed or in progress,
53 * this thread was already counted as stopped.
54 */
55 if (child->signal->flags & SIGNAL_STOP_STOPPED ||
56 child->signal->group_stop_count)
d9ae90ac 57 __set_task_state(child, TASK_STOPPED);
1ee11844 58 else
1da177e4 59 signal_wake_up(child, 1);
1da177e4
LT
60 }
61 spin_unlock(&child->sighand->siglock);
62}
63
64/*
65 * unptrace a task: move it back to its original parent and
66 * remove it from the ptrace list.
67 *
68 * Must be called with the tasklist lock write-held.
69 */
36c8b586 70void __ptrace_unlink(struct task_struct *child)
1da177e4 71{
5ecfbae0
ON
72 BUG_ON(!child->ptrace);
73
1da177e4 74 child->ptrace = 0;
f470021a
RM
75 child->parent = child->real_parent;
76 list_del_init(&child->ptrace_entry);
1da177e4 77
6618a3e2 78 if (task_is_traced(child))
e57a5059 79 ptrace_untrace(child);
1da177e4
LT
80}
81
82/*
83 * Check that we have indeed attached to the thing..
84 */
85int ptrace_check_attach(struct task_struct *child, int kill)
86{
87 int ret = -ESRCH;
88
89 /*
90 * We take the read lock around doing both checks to close a
91 * possible race where someone else was tracing our child and
92 * detached between these two checks. After this locked check,
93 * we are sure that this is our traced child and that can only
94 * be changed by us so it's not changing right after this.
95 */
96 read_lock(&tasklist_lock);
c0c0b649 97 if ((child->ptrace & PT_PTRACED) && child->parent == current) {
1da177e4 98 ret = 0;
c0c0b649
ON
99 /*
100 * child->sighand can't be NULL, release_task()
101 * does ptrace_unlink() before __exit_signal().
102 */
1da177e4 103 spin_lock_irq(&child->sighand->siglock);
d9ae90ac 104 if (task_is_stopped(child))
1da177e4 105 child->state = TASK_TRACED;
d9ae90ac 106 else if (!task_is_traced(child) && !kill)
1da177e4 107 ret = -ESRCH;
1da177e4
LT
108 spin_unlock_irq(&child->sighand->siglock);
109 }
110 read_unlock(&tasklist_lock);
111
d9ae90ac 112 if (!ret && !kill)
85ba2d86 113 ret = wait_task_inactive(child, TASK_TRACED) ? 0 : -ESRCH;
1da177e4
LT
114
115 /* All systems go.. */
116 return ret;
117}
118
006ebb40 119int __ptrace_may_access(struct task_struct *task, unsigned int mode)
ab8d11be 120{
c69e8d9c 121 const struct cred *cred = current_cred(), *tcred;
b6dff3ec 122
df26c40e
EB
123 /* May we inspect the given task?
124 * This check is used both for attaching with ptrace
125 * and for allowing access to sensitive information in /proc.
126 *
127 * ptrace_attach denies several cases that /proc allows
128 * because setting up the necessary parent/child relationship
129 * or halting the specified task is impossible.
130 */
131 int dumpable = 0;
132 /* Don't let security modules deny introspection */
133 if (task == current)
134 return 0;
c69e8d9c
DH
135 rcu_read_lock();
136 tcred = __task_cred(task);
137 if ((cred->uid != tcred->euid ||
138 cred->uid != tcred->suid ||
139 cred->uid != tcred->uid ||
140 cred->gid != tcred->egid ||
141 cred->gid != tcred->sgid ||
142 cred->gid != tcred->gid) &&
143 !capable(CAP_SYS_PTRACE)) {
144 rcu_read_unlock();
ab8d11be 145 return -EPERM;
c69e8d9c
DH
146 }
147 rcu_read_unlock();
ab8d11be 148 smp_rmb();
df26c40e 149 if (task->mm)
6c5d5238 150 dumpable = get_dumpable(task->mm);
df26c40e 151 if (!dumpable && !capable(CAP_SYS_PTRACE))
ab8d11be
MS
152 return -EPERM;
153
9e48858f 154 return security_ptrace_access_check(task, mode);
ab8d11be
MS
155}
156
006ebb40 157bool ptrace_may_access(struct task_struct *task, unsigned int mode)
ab8d11be
MS
158{
159 int err;
160 task_lock(task);
006ebb40 161 err = __ptrace_may_access(task, mode);
ab8d11be 162 task_unlock(task);
3a709703 163 return !err;
ab8d11be
MS
164}
165
1da177e4
LT
166int ptrace_attach(struct task_struct *task)
167{
168 int retval;
f5b40e36 169
a5cb013d
AV
170 audit_ptrace(task);
171
1da177e4 172 retval = -EPERM;
b79b7ba9
ON
173 if (unlikely(task->flags & PF_KTHREAD))
174 goto out;
bac0abd6 175 if (same_thread_group(task, current))
f5b40e36
LT
176 goto out;
177
f2f0b00a
ON
178 /*
179 * Protect exec's credential calculations against our interference;
5e751e99
DH
180 * interference; SUID, SGID and LSM creds get determined differently
181 * under ptrace.
d84f4f99 182 */
793285fc 183 retval = -ERESTARTNOINTR;
9b1bf12d 184 if (mutex_lock_interruptible(&task->signal->cred_guard_mutex))
d84f4f99 185 goto out;
f5b40e36 186
4b105cbb 187 task_lock(task);
006ebb40 188 retval = __ptrace_may_access(task, PTRACE_MODE_ATTACH);
4b105cbb 189 task_unlock(task);
1da177e4 190 if (retval)
4b105cbb 191 goto unlock_creds;
1da177e4 192
4b105cbb 193 write_lock_irq(&tasklist_lock);
b79b7ba9
ON
194 retval = -EPERM;
195 if (unlikely(task->exit_state))
4b105cbb 196 goto unlock_tasklist;
f2f0b00a 197 if (task->ptrace)
4b105cbb 198 goto unlock_tasklist;
b79b7ba9 199
f2f0b00a 200 task->ptrace = PT_PTRACED;
1da177e4
LT
201 if (capable(CAP_SYS_PTRACE))
202 task->ptrace |= PT_PTRACE_CAP;
1da177e4 203
1da177e4 204 __ptrace_link(task, current);
33e9fc7d 205 send_sig_info(SIGSTOP, SEND_SIG_FORCED, task);
b79b7ba9
ON
206
207 retval = 0;
4b105cbb
ON
208unlock_tasklist:
209 write_unlock_irq(&tasklist_lock);
210unlock_creds:
9b1bf12d 211 mutex_unlock(&task->signal->cred_guard_mutex);
f5b40e36 212out:
1da177e4
LT
213 return retval;
214}
215
f2f0b00a
ON
216/**
217 * ptrace_traceme -- helper for PTRACE_TRACEME
218 *
219 * Performs checks and sets PT_PTRACED.
220 * Should be used by all ptrace implementations for PTRACE_TRACEME.
221 */
222int ptrace_traceme(void)
223{
224 int ret = -EPERM;
225
4b105cbb
ON
226 write_lock_irq(&tasklist_lock);
227 /* Are we already being traced? */
f2f0b00a 228 if (!current->ptrace) {
f2f0b00a 229 ret = security_ptrace_traceme(current->parent);
f2f0b00a
ON
230 /*
231 * Check PF_EXITING to ensure ->real_parent has not passed
232 * exit_ptrace(). Otherwise we don't report the error but
233 * pretend ->real_parent untraces us right after return.
234 */
235 if (!ret && !(current->real_parent->flags & PF_EXITING)) {
236 current->ptrace = PT_PTRACED;
237 __ptrace_link(current, current->real_parent);
238 }
f2f0b00a 239 }
4b105cbb
ON
240 write_unlock_irq(&tasklist_lock);
241
f2f0b00a
ON
242 return ret;
243}
244
39c626ae
ON
245/*
246 * Called with irqs disabled, returns true if childs should reap themselves.
247 */
248static int ignoring_children(struct sighand_struct *sigh)
249{
250 int ret;
251 spin_lock(&sigh->siglock);
252 ret = (sigh->action[SIGCHLD-1].sa.sa_handler == SIG_IGN) ||
253 (sigh->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT);
254 spin_unlock(&sigh->siglock);
255 return ret;
256}
257
258/*
259 * Called with tasklist_lock held for writing.
260 * Unlink a traced task, and clean it up if it was a traced zombie.
261 * Return true if it needs to be reaped with release_task().
262 * (We can't call release_task() here because we already hold tasklist_lock.)
263 *
264 * If it's a zombie, our attachedness prevented normal parent notification
265 * or self-reaping. Do notification now if it would have happened earlier.
266 * If it should reap itself, return true.
267 *
a7f0765e
ON
268 * If it's our own child, there is no notification to do. But if our normal
269 * children self-reap, then this child was prevented by ptrace and we must
270 * reap it now, in that case we must also wake up sub-threads sleeping in
271 * do_wait().
39c626ae
ON
272 */
273static bool __ptrace_detach(struct task_struct *tracer, struct task_struct *p)
274{
275 __ptrace_unlink(p);
276
277 if (p->exit_state == EXIT_ZOMBIE) {
278 if (!task_detached(p) && thread_group_empty(p)) {
279 if (!same_thread_group(p->real_parent, tracer))
280 do_notify_parent(p, p->exit_signal);
a7f0765e
ON
281 else if (ignoring_children(tracer->sighand)) {
282 __wake_up_parent(p, tracer);
39c626ae 283 p->exit_signal = -1;
a7f0765e 284 }
39c626ae
ON
285 }
286 if (task_detached(p)) {
287 /* Mark it as in the process of being reaped. */
288 p->exit_state = EXIT_DEAD;
289 return true;
290 }
291 }
292
293 return false;
294}
295
1da177e4
LT
296int ptrace_detach(struct task_struct *child, unsigned int data)
297{
39c626ae 298 bool dead = false;
4576145c 299
7ed20e1a 300 if (!valid_signal(data))
5ecfbae0 301 return -EIO;
1da177e4
LT
302
303 /* Architecture-specific hardware disable .. */
304 ptrace_disable(child);
7d941432 305 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
1da177e4 306
95c3eb76 307 write_lock_irq(&tasklist_lock);
39c626ae
ON
308 /*
309 * This child can be already killed. Make sure de_thread() or
310 * our sub-thread doing do_wait() didn't do release_task() yet.
311 */
95c3eb76
ON
312 if (child->ptrace) {
313 child->exit_code = data;
4576145c 314 dead = __ptrace_detach(current, child);
edaba2c5
ON
315 if (!child->exit_state)
316 wake_up_process(child);
95c3eb76 317 }
1da177e4
LT
318 write_unlock_irq(&tasklist_lock);
319
4576145c
ON
320 if (unlikely(dead))
321 release_task(child);
322
1da177e4
LT
323 return 0;
324}
325
39c626ae 326/*
c7e49c14
ON
327 * Detach all tasks we were using ptrace on. Called with tasklist held
328 * for writing, and returns with it held too. But note it can release
329 * and reacquire the lock.
39c626ae
ON
330 */
331void exit_ptrace(struct task_struct *tracer)
c4b5ed25
NK
332 __releases(&tasklist_lock)
333 __acquires(&tasklist_lock)
39c626ae
ON
334{
335 struct task_struct *p, *n;
336 LIST_HEAD(ptrace_dead);
337
c7e49c14
ON
338 if (likely(list_empty(&tracer->ptraced)))
339 return;
340
39c626ae
ON
341 list_for_each_entry_safe(p, n, &tracer->ptraced, ptrace_entry) {
342 if (__ptrace_detach(tracer, p))
343 list_add(&p->ptrace_entry, &ptrace_dead);
344 }
39c626ae 345
c7e49c14 346 write_unlock_irq(&tasklist_lock);
39c626ae
ON
347 BUG_ON(!list_empty(&tracer->ptraced));
348
349 list_for_each_entry_safe(p, n, &ptrace_dead, ptrace_entry) {
350 list_del_init(&p->ptrace_entry);
351 release_task(p);
352 }
c7e49c14
ON
353
354 write_lock_irq(&tasklist_lock);
39c626ae
ON
355}
356
1da177e4
LT
357int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len)
358{
359 int copied = 0;
360
361 while (len > 0) {
362 char buf[128];
363 int this_len, retval;
364
365 this_len = (len > sizeof(buf)) ? sizeof(buf) : len;
366 retval = access_process_vm(tsk, src, buf, this_len, 0);
367 if (!retval) {
368 if (copied)
369 break;
370 return -EIO;
371 }
372 if (copy_to_user(dst, buf, retval))
373 return -EFAULT;
374 copied += retval;
375 src += retval;
376 dst += retval;
3a709703 377 len -= retval;
1da177e4
LT
378 }
379 return copied;
380}
381
382int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len)
383{
384 int copied = 0;
385
386 while (len > 0) {
387 char buf[128];
388 int this_len, retval;
389
390 this_len = (len > sizeof(buf)) ? sizeof(buf) : len;
391 if (copy_from_user(buf, src, this_len))
392 return -EFAULT;
393 retval = access_process_vm(tsk, dst, buf, this_len, 1);
394 if (!retval) {
395 if (copied)
396 break;
397 return -EIO;
398 }
399 copied += retval;
400 src += retval;
401 dst += retval;
3a709703 402 len -= retval;
1da177e4
LT
403 }
404 return copied;
405}
406
4abf9869 407static int ptrace_setoptions(struct task_struct *child, unsigned long data)
1da177e4
LT
408{
409 child->ptrace &= ~PT_TRACE_MASK;
410
411 if (data & PTRACE_O_TRACESYSGOOD)
412 child->ptrace |= PT_TRACESYSGOOD;
413
414 if (data & PTRACE_O_TRACEFORK)
415 child->ptrace |= PT_TRACE_FORK;
416
417 if (data & PTRACE_O_TRACEVFORK)
418 child->ptrace |= PT_TRACE_VFORK;
419
420 if (data & PTRACE_O_TRACECLONE)
421 child->ptrace |= PT_TRACE_CLONE;
422
423 if (data & PTRACE_O_TRACEEXEC)
424 child->ptrace |= PT_TRACE_EXEC;
425
426 if (data & PTRACE_O_TRACEVFORKDONE)
427 child->ptrace |= PT_TRACE_VFORK_DONE;
428
429 if (data & PTRACE_O_TRACEEXIT)
430 child->ptrace |= PT_TRACE_EXIT;
431
432 return (data & ~PTRACE_O_MASK) ? -EINVAL : 0;
433}
434
e16b2781 435static int ptrace_getsiginfo(struct task_struct *child, siginfo_t *info)
1da177e4 436{
e4961254 437 unsigned long flags;
1da177e4
LT
438 int error = -ESRCH;
439
e4961254 440 if (lock_task_sighand(child, &flags)) {
1da177e4 441 error = -EINVAL;
1da177e4 442 if (likely(child->last_siginfo != NULL)) {
e16b2781 443 *info = *child->last_siginfo;
1da177e4
LT
444 error = 0;
445 }
e4961254 446 unlock_task_sighand(child, &flags);
1da177e4 447 }
1da177e4
LT
448 return error;
449}
450
e16b2781 451static int ptrace_setsiginfo(struct task_struct *child, const siginfo_t *info)
1da177e4 452{
e4961254 453 unsigned long flags;
1da177e4
LT
454 int error = -ESRCH;
455
e4961254 456 if (lock_task_sighand(child, &flags)) {
1da177e4 457 error = -EINVAL;
1da177e4 458 if (likely(child->last_siginfo != NULL)) {
e16b2781 459 *child->last_siginfo = *info;
1da177e4
LT
460 error = 0;
461 }
e4961254 462 unlock_task_sighand(child, &flags);
1da177e4 463 }
1da177e4
LT
464 return error;
465}
466
36df29d7
RM
467
468#ifdef PTRACE_SINGLESTEP
469#define is_singlestep(request) ((request) == PTRACE_SINGLESTEP)
470#else
471#define is_singlestep(request) 0
472#endif
473
5b88abbf
RM
474#ifdef PTRACE_SINGLEBLOCK
475#define is_singleblock(request) ((request) == PTRACE_SINGLEBLOCK)
476#else
477#define is_singleblock(request) 0
478#endif
479
36df29d7
RM
480#ifdef PTRACE_SYSEMU
481#define is_sysemu_singlestep(request) ((request) == PTRACE_SYSEMU_SINGLESTEP)
482#else
483#define is_sysemu_singlestep(request) 0
484#endif
485
4abf9869
NK
486static int ptrace_resume(struct task_struct *child, long request,
487 unsigned long data)
36df29d7
RM
488{
489 if (!valid_signal(data))
490 return -EIO;
491
492 if (request == PTRACE_SYSCALL)
493 set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
494 else
495 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
496
497#ifdef TIF_SYSCALL_EMU
498 if (request == PTRACE_SYSEMU || request == PTRACE_SYSEMU_SINGLESTEP)
499 set_tsk_thread_flag(child, TIF_SYSCALL_EMU);
500 else
501 clear_tsk_thread_flag(child, TIF_SYSCALL_EMU);
502#endif
503
5b88abbf
RM
504 if (is_singleblock(request)) {
505 if (unlikely(!arch_has_block_step()))
506 return -EIO;
507 user_enable_block_step(child);
508 } else if (is_singlestep(request) || is_sysemu_singlestep(request)) {
36df29d7
RM
509 if (unlikely(!arch_has_single_step()))
510 return -EIO;
511 user_enable_single_step(child);
3a709703 512 } else {
36df29d7 513 user_disable_single_step(child);
3a709703 514 }
36df29d7
RM
515
516 child->exit_code = data;
517 wake_up_process(child);
518
519 return 0;
520}
521
2225a122
SS
522#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
523
524static const struct user_regset *
525find_regset(const struct user_regset_view *view, unsigned int type)
526{
527 const struct user_regset *regset;
528 int n;
529
530 for (n = 0; n < view->n; ++n) {
531 regset = view->regsets + n;
532 if (regset->core_note_type == type)
533 return regset;
534 }
535
536 return NULL;
537}
538
539static int ptrace_regset(struct task_struct *task, int req, unsigned int type,
540 struct iovec *kiov)
541{
542 const struct user_regset_view *view = task_user_regset_view(task);
543 const struct user_regset *regset = find_regset(view, type);
544 int regset_no;
545
546 if (!regset || (kiov->iov_len % regset->size) != 0)
c6a0dd7e 547 return -EINVAL;
2225a122
SS
548
549 regset_no = regset - view->regsets;
550 kiov->iov_len = min(kiov->iov_len,
551 (__kernel_size_t) (regset->n * regset->size));
552
553 if (req == PTRACE_GETREGSET)
554 return copy_regset_to_user(task, view, regset_no, 0,
555 kiov->iov_len, kiov->iov_base);
556 else
557 return copy_regset_from_user(task, view, regset_no, 0,
558 kiov->iov_len, kiov->iov_base);
559}
560
561#endif
562
1da177e4 563int ptrace_request(struct task_struct *child, long request,
4abf9869 564 unsigned long addr, unsigned long data)
1da177e4
LT
565{
566 int ret = -EIO;
e16b2781 567 siginfo_t siginfo;
9fed81dc
NK
568 void __user *datavp = (void __user *) data;
569 unsigned long __user *datalp = datavp;
1da177e4
LT
570
571 switch (request) {
16c3e389
RM
572 case PTRACE_PEEKTEXT:
573 case PTRACE_PEEKDATA:
574 return generic_ptrace_peekdata(child, addr, data);
575 case PTRACE_POKETEXT:
576 case PTRACE_POKEDATA:
577 return generic_ptrace_pokedata(child, addr, data);
578
1da177e4
LT
579#ifdef PTRACE_OLDSETOPTIONS
580 case PTRACE_OLDSETOPTIONS:
581#endif
582 case PTRACE_SETOPTIONS:
583 ret = ptrace_setoptions(child, data);
584 break;
585 case PTRACE_GETEVENTMSG:
9fed81dc 586 ret = put_user(child->ptrace_message, datalp);
1da177e4 587 break;
e16b2781 588
1da177e4 589 case PTRACE_GETSIGINFO:
e16b2781
RM
590 ret = ptrace_getsiginfo(child, &siginfo);
591 if (!ret)
9fed81dc 592 ret = copy_siginfo_to_user(datavp, &siginfo);
1da177e4 593 break;
e16b2781 594
1da177e4 595 case PTRACE_SETSIGINFO:
9fed81dc 596 if (copy_from_user(&siginfo, datavp, sizeof siginfo))
e16b2781
RM
597 ret = -EFAULT;
598 else
599 ret = ptrace_setsiginfo(child, &siginfo);
1da177e4 600 break;
e16b2781 601
1bcf5482
AD
602 case PTRACE_DETACH: /* detach a process that was attached. */
603 ret = ptrace_detach(child, data);
604 break;
36df29d7 605
9c1a1259
MF
606#ifdef CONFIG_BINFMT_ELF_FDPIC
607 case PTRACE_GETFDPIC: {
e0129ef9 608 struct mm_struct *mm = get_task_mm(child);
9c1a1259
MF
609 unsigned long tmp = 0;
610
e0129ef9
ON
611 ret = -ESRCH;
612 if (!mm)
613 break;
614
9c1a1259
MF
615 switch (addr) {
616 case PTRACE_GETFDPIC_EXEC:
e0129ef9 617 tmp = mm->context.exec_fdpic_loadmap;
9c1a1259
MF
618 break;
619 case PTRACE_GETFDPIC_INTERP:
e0129ef9 620 tmp = mm->context.interp_fdpic_loadmap;
9c1a1259
MF
621 break;
622 default:
623 break;
624 }
e0129ef9 625 mmput(mm);
9c1a1259 626
9fed81dc 627 ret = put_user(tmp, datalp);
9c1a1259
MF
628 break;
629 }
630#endif
631
36df29d7
RM
632#ifdef PTRACE_SINGLESTEP
633 case PTRACE_SINGLESTEP:
634#endif
5b88abbf
RM
635#ifdef PTRACE_SINGLEBLOCK
636 case PTRACE_SINGLEBLOCK:
637#endif
36df29d7
RM
638#ifdef PTRACE_SYSEMU
639 case PTRACE_SYSEMU:
640 case PTRACE_SYSEMU_SINGLESTEP:
641#endif
642 case PTRACE_SYSCALL:
643 case PTRACE_CONT:
644 return ptrace_resume(child, request, data);
645
646 case PTRACE_KILL:
647 if (child->exit_state) /* already dead */
648 return 0;
649 return ptrace_resume(child, request, SIGKILL);
650
2225a122
SS
651#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
652 case PTRACE_GETREGSET:
653 case PTRACE_SETREGSET:
654 {
655 struct iovec kiov;
9fed81dc 656 struct iovec __user *uiov = datavp;
2225a122
SS
657
658 if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov)))
659 return -EFAULT;
660
661 if (__get_user(kiov.iov_base, &uiov->iov_base) ||
662 __get_user(kiov.iov_len, &uiov->iov_len))
663 return -EFAULT;
664
665 ret = ptrace_regset(child, request, addr, &kiov);
666 if (!ret)
667 ret = __put_user(kiov.iov_len, &uiov->iov_len);
668 break;
669 }
670#endif
1da177e4
LT
671 default:
672 break;
673 }
674
675 return ret;
676}
481bed45 677
8053bdd5 678static struct task_struct *ptrace_get_task_struct(pid_t pid)
6b9c7ed8
CH
679{
680 struct task_struct *child;
481bed45 681
8053bdd5 682 rcu_read_lock();
228ebcbe 683 child = find_task_by_vpid(pid);
481bed45
CH
684 if (child)
685 get_task_struct(child);
8053bdd5 686 rcu_read_unlock();
f400e198 687
481bed45 688 if (!child)
6b9c7ed8
CH
689 return ERR_PTR(-ESRCH);
690 return child;
481bed45
CH
691}
692
0ac15559
CH
693#ifndef arch_ptrace_attach
694#define arch_ptrace_attach(child) do { } while (0)
695#endif
696
4abf9869
NK
697SYSCALL_DEFINE4(ptrace, long, request, long, pid, unsigned long, addr,
698 unsigned long, data)
481bed45
CH
699{
700 struct task_struct *child;
701 long ret;
702
6b9c7ed8
CH
703 if (request == PTRACE_TRACEME) {
704 ret = ptrace_traceme();
6ea6dd93
HS
705 if (!ret)
706 arch_ptrace_attach(current);
481bed45 707 goto out;
6b9c7ed8
CH
708 }
709
710 child = ptrace_get_task_struct(pid);
711 if (IS_ERR(child)) {
712 ret = PTR_ERR(child);
713 goto out;
714 }
481bed45
CH
715
716 if (request == PTRACE_ATTACH) {
717 ret = ptrace_attach(child);
0ac15559
CH
718 /*
719 * Some architectures need to do book-keeping after
720 * a ptrace attach.
721 */
722 if (!ret)
723 arch_ptrace_attach(child);
005f18df 724 goto out_put_task_struct;
481bed45
CH
725 }
726
727 ret = ptrace_check_attach(child, request == PTRACE_KILL);
728 if (ret < 0)
729 goto out_put_task_struct;
730
731 ret = arch_ptrace(child, request, addr, data);
481bed45
CH
732
733 out_put_task_struct:
734 put_task_struct(child);
735 out:
481bed45
CH
736 return ret;
737}
76647323 738
4abf9869
NK
739int generic_ptrace_peekdata(struct task_struct *tsk, unsigned long addr,
740 unsigned long data)
76647323
AD
741{
742 unsigned long tmp;
743 int copied;
744
745 copied = access_process_vm(tsk, addr, &tmp, sizeof(tmp), 0);
746 if (copied != sizeof(tmp))
747 return -EIO;
748 return put_user(tmp, (unsigned long __user *)data);
749}
f284ce72 750
4abf9869
NK
751int generic_ptrace_pokedata(struct task_struct *tsk, unsigned long addr,
752 unsigned long data)
f284ce72
AD
753{
754 int copied;
755
756 copied = access_process_vm(tsk, addr, &data, sizeof(data), 1);
757 return (copied == sizeof(data)) ? 0 : -EIO;
758}
032d82d9 759
96b8936a 760#if defined CONFIG_COMPAT
032d82d9
RM
761#include <linux/compat.h>
762
763int compat_ptrace_request(struct task_struct *child, compat_long_t request,
764 compat_ulong_t addr, compat_ulong_t data)
765{
766 compat_ulong_t __user *datap = compat_ptr(data);
767 compat_ulong_t word;
e16b2781 768 siginfo_t siginfo;
032d82d9
RM
769 int ret;
770
771 switch (request) {
772 case PTRACE_PEEKTEXT:
773 case PTRACE_PEEKDATA:
774 ret = access_process_vm(child, addr, &word, sizeof(word), 0);
775 if (ret != sizeof(word))
776 ret = -EIO;
777 else
778 ret = put_user(word, datap);
779 break;
780
781 case PTRACE_POKETEXT:
782 case PTRACE_POKEDATA:
783 ret = access_process_vm(child, addr, &data, sizeof(data), 1);
784 ret = (ret != sizeof(data) ? -EIO : 0);
785 break;
786
787 case PTRACE_GETEVENTMSG:
788 ret = put_user((compat_ulong_t) child->ptrace_message, datap);
789 break;
790
e16b2781
RM
791 case PTRACE_GETSIGINFO:
792 ret = ptrace_getsiginfo(child, &siginfo);
793 if (!ret)
794 ret = copy_siginfo_to_user32(
795 (struct compat_siginfo __user *) datap,
796 &siginfo);
797 break;
798
799 case PTRACE_SETSIGINFO:
800 memset(&siginfo, 0, sizeof siginfo);
801 if (copy_siginfo_from_user32(
802 &siginfo, (struct compat_siginfo __user *) datap))
803 ret = -EFAULT;
804 else
805 ret = ptrace_setsiginfo(child, &siginfo);
806 break;
2225a122
SS
807#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
808 case PTRACE_GETREGSET:
809 case PTRACE_SETREGSET:
810 {
811 struct iovec kiov;
812 struct compat_iovec __user *uiov =
813 (struct compat_iovec __user *) datap;
814 compat_uptr_t ptr;
815 compat_size_t len;
816
817 if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov)))
818 return -EFAULT;
819
820 if (__get_user(ptr, &uiov->iov_base) ||
821 __get_user(len, &uiov->iov_len))
822 return -EFAULT;
823
824 kiov.iov_base = compat_ptr(ptr);
825 kiov.iov_len = len;
826
827 ret = ptrace_regset(child, request, addr, &kiov);
828 if (!ret)
829 ret = __put_user(kiov.iov_len, &uiov->iov_len);
830 break;
831 }
832#endif
e16b2781 833
032d82d9
RM
834 default:
835 ret = ptrace_request(child, request, addr, data);
836 }
837
838 return ret;
839}
c269f196 840
c269f196
RM
841asmlinkage long compat_sys_ptrace(compat_long_t request, compat_long_t pid,
842 compat_long_t addr, compat_long_t data)
843{
844 struct task_struct *child;
845 long ret;
846
c269f196
RM
847 if (request == PTRACE_TRACEME) {
848 ret = ptrace_traceme();
849 goto out;
850 }
851
852 child = ptrace_get_task_struct(pid);
853 if (IS_ERR(child)) {
854 ret = PTR_ERR(child);
855 goto out;
856 }
857
858 if (request == PTRACE_ATTACH) {
859 ret = ptrace_attach(child);
860 /*
861 * Some architectures need to do book-keeping after
862 * a ptrace attach.
863 */
864 if (!ret)
865 arch_ptrace_attach(child);
866 goto out_put_task_struct;
867 }
868
869 ret = ptrace_check_attach(child, request == PTRACE_KILL);
870 if (!ret)
871 ret = compat_arch_ptrace(child, request, addr, data);
872
873 out_put_task_struct:
874 put_task_struct(child);
875 out:
c269f196
RM
876 return ret;
877}
96b8936a 878#endif /* CONFIG_COMPAT */