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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 | ||
10 | #include <linux/capability.h> | |
11 | #include <linux/export.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> | |
17 | #include <linux/ptrace.h> | |
18 | #include <linux/security.h> | |
19 | #include <linux/signal.h> | |
20 | #include <linux/uio.h> | |
21 | #include <linux/audit.h> | |
22 | #include <linux/pid_namespace.h> | |
23 | #include <linux/syscalls.h> | |
24 | #include <linux/uaccess.h> | |
25 | #include <linux/regset.h> | |
26 | #include <linux/hw_breakpoint.h> | |
27 | #include <linux/cn_proc.h> | |
28 | #include <linux/compat.h> | |
29 | ||
30 | ||
31 | /* | |
32 | * ptrace a task: make the debugger its new parent and | |
33 | * move it to the ptrace list. | |
34 | * | |
35 | * Must be called with the tasklist lock write-held. | |
36 | */ | |
37 | void __ptrace_link(struct task_struct *child, struct task_struct *new_parent) | |
38 | { | |
39 | BUG_ON(!list_empty(&child->ptrace_entry)); | |
40 | list_add(&child->ptrace_entry, &new_parent->ptraced); | |
41 | child->parent = new_parent; | |
42 | } | |
43 | ||
44 | /** | |
45 | * __ptrace_unlink - unlink ptracee and restore its execution state | |
46 | * @child: ptracee to be unlinked | |
47 | * | |
48 | * Remove @child from the ptrace list, move it back to the original parent, | |
49 | * and restore the execution state so that it conforms to the group stop | |
50 | * state. | |
51 | * | |
52 | * Unlinking can happen via two paths - explicit PTRACE_DETACH or ptracer | |
53 | * exiting. For PTRACE_DETACH, unless the ptracee has been killed between | |
54 | * ptrace_check_attach() and here, it's guaranteed to be in TASK_TRACED. | |
55 | * If the ptracer is exiting, the ptracee can be in any state. | |
56 | * | |
57 | * After detach, the ptracee should be in a state which conforms to the | |
58 | * group stop. If the group is stopped or in the process of stopping, the | |
59 | * ptracee should be put into TASK_STOPPED; otherwise, it should be woken | |
60 | * up from TASK_TRACED. | |
61 | * | |
62 | * If the ptracee is in TASK_TRACED and needs to be moved to TASK_STOPPED, | |
63 | * it goes through TRACED -> RUNNING -> STOPPED transition which is similar | |
64 | * to but in the opposite direction of what happens while attaching to a | |
65 | * stopped task. However, in this direction, the intermediate RUNNING | |
66 | * state is not hidden even from the current ptracer and if it immediately | |
67 | * re-attaches and performs a WNOHANG wait(2), it may fail. | |
68 | * | |
69 | * CONTEXT: | |
70 | * write_lock_irq(tasklist_lock) | |
71 | */ | |
72 | void __ptrace_unlink(struct task_struct *child) | |
73 | { | |
74 | BUG_ON(!child->ptrace); | |
75 | ||
76 | child->ptrace = 0; | |
77 | child->parent = child->real_parent; | |
78 | list_del_init(&child->ptrace_entry); | |
79 | ||
80 | spin_lock(&child->sighand->siglock); | |
81 | ||
82 | /* | |
83 | * Clear all pending traps and TRAPPING. TRAPPING should be | |
84 | * cleared regardless of JOBCTL_STOP_PENDING. Do it explicitly. | |
85 | */ | |
86 | task_clear_jobctl_pending(child, JOBCTL_TRAP_MASK); | |
87 | task_clear_jobctl_trapping(child); | |
88 | ||
89 | /* | |
90 | * Reinstate JOBCTL_STOP_PENDING if group stop is in effect and | |
91 | * @child isn't dead. | |
92 | */ | |
93 | if (!(child->flags & PF_EXITING) && | |
94 | (child->signal->flags & SIGNAL_STOP_STOPPED || | |
95 | child->signal->group_stop_count)) { | |
96 | child->jobctl |= JOBCTL_STOP_PENDING; | |
97 | ||
98 | /* | |
99 | * This is only possible if this thread was cloned by the | |
100 | * traced task running in the stopped group, set the signal | |
101 | * for the future reports. | |
102 | * FIXME: we should change ptrace_init_task() to handle this | |
103 | * case. | |
104 | */ | |
105 | if (!(child->jobctl & JOBCTL_STOP_SIGMASK)) | |
106 | child->jobctl |= SIGSTOP; | |
107 | } | |
108 | ||
109 | /* | |
110 | * If transition to TASK_STOPPED is pending or in TASK_TRACED, kick | |
111 | * @child in the butt. Note that @resume should be used iff @child | |
112 | * is in TASK_TRACED; otherwise, we might unduly disrupt | |
113 | * TASK_KILLABLE sleeps. | |
114 | */ | |
115 | if (child->jobctl & JOBCTL_STOP_PENDING || task_is_traced(child)) | |
116 | ptrace_signal_wake_up(child, true); | |
117 | ||
118 | spin_unlock(&child->sighand->siglock); | |
119 | } | |
120 | ||
121 | /* Ensure that nothing can wake it up, even SIGKILL */ | |
122 | static bool ptrace_freeze_traced(struct task_struct *task) | |
123 | { | |
124 | bool ret = false; | |
125 | ||
126 | /* Lockless, nobody but us can set this flag */ | |
127 | if (task->jobctl & JOBCTL_LISTENING) | |
128 | return ret; | |
129 | ||
130 | spin_lock_irq(&task->sighand->siglock); | |
131 | if (task_is_traced(task) && !__fatal_signal_pending(task)) { | |
132 | task->state = __TASK_TRACED; | |
133 | ret = true; | |
134 | } | |
135 | spin_unlock_irq(&task->sighand->siglock); | |
136 | ||
137 | return ret; | |
138 | } | |
139 | ||
140 | static void ptrace_unfreeze_traced(struct task_struct *task) | |
141 | { | |
142 | if (task->state != __TASK_TRACED) | |
143 | return; | |
144 | ||
145 | WARN_ON(!task->ptrace || task->parent != current); | |
146 | ||
147 | spin_lock_irq(&task->sighand->siglock); | |
148 | if (__fatal_signal_pending(task)) | |
149 | wake_up_state(task, __TASK_TRACED); | |
150 | else | |
151 | task->state = TASK_TRACED; | |
152 | spin_unlock_irq(&task->sighand->siglock); | |
153 | } | |
154 | ||
155 | /** | |
156 | * ptrace_check_attach - check whether ptracee is ready for ptrace operation | |
157 | * @child: ptracee to check for | |
158 | * @ignore_state: don't check whether @child is currently %TASK_TRACED | |
159 | * | |
160 | * Check whether @child is being ptraced by %current and ready for further | |
161 | * ptrace operations. If @ignore_state is %false, @child also should be in | |
162 | * %TASK_TRACED state and on return the child is guaranteed to be traced | |
163 | * and not executing. If @ignore_state is %true, @child can be in any | |
164 | * state. | |
165 | * | |
166 | * CONTEXT: | |
167 | * Grabs and releases tasklist_lock and @child->sighand->siglock. | |
168 | * | |
169 | * RETURNS: | |
170 | * 0 on success, -ESRCH if %child is not ready. | |
171 | */ | |
172 | static int ptrace_check_attach(struct task_struct *child, bool ignore_state) | |
173 | { | |
174 | int ret = -ESRCH; | |
175 | ||
176 | /* | |
177 | * We take the read lock around doing both checks to close a | |
178 | * possible race where someone else was tracing our child and | |
179 | * detached between these two checks. After this locked check, | |
180 | * we are sure that this is our traced child and that can only | |
181 | * be changed by us so it's not changing right after this. | |
182 | */ | |
183 | read_lock(&tasklist_lock); | |
184 | if (child->ptrace && child->parent == current) { | |
185 | WARN_ON(child->state == __TASK_TRACED); | |
186 | /* | |
187 | * child->sighand can't be NULL, release_task() | |
188 | * does ptrace_unlink() before __exit_signal(). | |
189 | */ | |
190 | if (ignore_state || ptrace_freeze_traced(child)) | |
191 | ret = 0; | |
192 | } | |
193 | read_unlock(&tasklist_lock); | |
194 | ||
195 | if (!ret && !ignore_state) { | |
196 | if (!wait_task_inactive(child, __TASK_TRACED)) { | |
197 | /* | |
198 | * This can only happen if may_ptrace_stop() fails and | |
199 | * ptrace_stop() changes ->state back to TASK_RUNNING, | |
200 | * so we should not worry about leaking __TASK_TRACED. | |
201 | */ | |
202 | WARN_ON(child->state == __TASK_TRACED); | |
203 | ret = -ESRCH; | |
204 | } | |
205 | } | |
206 | ||
207 | return ret; | |
208 | } | |
209 | ||
210 | static int ptrace_has_cap(struct user_namespace *ns, unsigned int mode) | |
211 | { | |
212 | if (mode & PTRACE_MODE_NOAUDIT) | |
213 | return has_ns_capability_noaudit(current, ns, CAP_SYS_PTRACE); | |
214 | else | |
215 | return has_ns_capability(current, ns, CAP_SYS_PTRACE); | |
216 | } | |
217 | ||
218 | /* Returns 0 on success, -errno on denial. */ | |
219 | static int __ptrace_may_access(struct task_struct *task, unsigned int mode) | |
220 | { | |
221 | const struct cred *cred = current_cred(), *tcred; | |
222 | ||
223 | /* May we inspect the given task? | |
224 | * This check is used both for attaching with ptrace | |
225 | * and for allowing access to sensitive information in /proc. | |
226 | * | |
227 | * ptrace_attach denies several cases that /proc allows | |
228 | * because setting up the necessary parent/child relationship | |
229 | * or halting the specified task is impossible. | |
230 | */ | |
231 | int dumpable = 0; | |
232 | /* Don't let security modules deny introspection */ | |
233 | if (same_thread_group(task, current)) | |
234 | return 0; | |
235 | rcu_read_lock(); | |
236 | tcred = __task_cred(task); | |
237 | if (uid_eq(cred->uid, tcred->euid) && | |
238 | uid_eq(cred->uid, tcred->suid) && | |
239 | uid_eq(cred->uid, tcred->uid) && | |
240 | gid_eq(cred->gid, tcred->egid) && | |
241 | gid_eq(cred->gid, tcred->sgid) && | |
242 | gid_eq(cred->gid, tcred->gid)) | |
243 | goto ok; | |
244 | if (ptrace_has_cap(tcred->user_ns, mode)) | |
245 | goto ok; | |
246 | rcu_read_unlock(); | |
247 | return -EPERM; | |
248 | ok: | |
249 | rcu_read_unlock(); | |
250 | smp_rmb(); | |
251 | if (task->mm) | |
252 | dumpable = get_dumpable(task->mm); | |
253 | rcu_read_lock(); | |
254 | if (dumpable != SUID_DUMP_USER && | |
255 | !ptrace_has_cap(__task_cred(task)->user_ns, mode)) { | |
256 | rcu_read_unlock(); | |
257 | return -EPERM; | |
258 | } | |
259 | rcu_read_unlock(); | |
260 | ||
261 | return security_ptrace_access_check(task, mode); | |
262 | } | |
263 | ||
264 | bool ptrace_may_access(struct task_struct *task, unsigned int mode) | |
265 | { | |
266 | int err; | |
267 | task_lock(task); | |
268 | err = __ptrace_may_access(task, mode); | |
269 | task_unlock(task); | |
270 | return !err; | |
271 | } | |
272 | ||
273 | static int ptrace_attach(struct task_struct *task, long request, | |
274 | unsigned long addr, | |
275 | unsigned long flags) | |
276 | { | |
277 | bool seize = (request == PTRACE_SEIZE); | |
278 | int retval; | |
279 | ||
280 | retval = -EIO; | |
281 | if (seize) { | |
282 | if (addr != 0) | |
283 | goto out; | |
284 | if (flags & ~(unsigned long)PTRACE_O_MASK) | |
285 | goto out; | |
286 | flags = PT_PTRACED | PT_SEIZED | (flags << PT_OPT_FLAG_SHIFT); | |
287 | } else { | |
288 | flags = PT_PTRACED; | |
289 | } | |
290 | ||
291 | audit_ptrace(task); | |
292 | ||
293 | retval = -EPERM; | |
294 | if (unlikely(task->flags & PF_KTHREAD)) | |
295 | goto out; | |
296 | if (same_thread_group(task, current)) | |
297 | goto out; | |
298 | ||
299 | /* | |
300 | * Protect exec's credential calculations against our interference; | |
301 | * SUID, SGID and LSM creds get determined differently | |
302 | * under ptrace. | |
303 | */ | |
304 | retval = -ERESTARTNOINTR; | |
305 | if (mutex_lock_interruptible(&task->signal->cred_guard_mutex)) | |
306 | goto out; | |
307 | ||
308 | task_lock(task); | |
309 | retval = __ptrace_may_access(task, PTRACE_MODE_ATTACH); | |
310 | task_unlock(task); | |
311 | if (retval) | |
312 | goto unlock_creds; | |
313 | ||
314 | write_lock_irq(&tasklist_lock); | |
315 | retval = -EPERM; | |
316 | if (unlikely(task->exit_state)) | |
317 | goto unlock_tasklist; | |
318 | if (task->ptrace) | |
319 | goto unlock_tasklist; | |
320 | ||
321 | if (seize) | |
322 | flags |= PT_SEIZED; | |
323 | rcu_read_lock(); | |
324 | if (ns_capable(__task_cred(task)->user_ns, CAP_SYS_PTRACE)) | |
325 | flags |= PT_PTRACE_CAP; | |
326 | rcu_read_unlock(); | |
327 | task->ptrace = flags; | |
328 | ||
329 | __ptrace_link(task, current); | |
330 | ||
331 | /* SEIZE doesn't trap tracee on attach */ | |
332 | if (!seize) | |
333 | send_sig_info(SIGSTOP, SEND_SIG_FORCED, task); | |
334 | ||
335 | spin_lock(&task->sighand->siglock); | |
336 | ||
337 | /* | |
338 | * If the task is already STOPPED, set JOBCTL_TRAP_STOP and | |
339 | * TRAPPING, and kick it so that it transits to TRACED. TRAPPING | |
340 | * will be cleared if the child completes the transition or any | |
341 | * event which clears the group stop states happens. We'll wait | |
342 | * for the transition to complete before returning from this | |
343 | * function. | |
344 | * | |
345 | * This hides STOPPED -> RUNNING -> TRACED transition from the | |
346 | * attaching thread but a different thread in the same group can | |
347 | * still observe the transient RUNNING state. IOW, if another | |
348 | * thread's WNOHANG wait(2) on the stopped tracee races against | |
349 | * ATTACH, the wait(2) may fail due to the transient RUNNING. | |
350 | * | |
351 | * The following task_is_stopped() test is safe as both transitions | |
352 | * in and out of STOPPED are protected by siglock. | |
353 | */ | |
354 | if (task_is_stopped(task) && | |
355 | task_set_jobctl_pending(task, JOBCTL_TRAP_STOP | JOBCTL_TRAPPING)) | |
356 | signal_wake_up_state(task, __TASK_STOPPED); | |
357 | ||
358 | spin_unlock(&task->sighand->siglock); | |
359 | ||
360 | retval = 0; | |
361 | unlock_tasklist: | |
362 | write_unlock_irq(&tasklist_lock); | |
363 | unlock_creds: | |
364 | mutex_unlock(&task->signal->cred_guard_mutex); | |
365 | out: | |
366 | if (!retval) { | |
367 | wait_on_bit(&task->jobctl, JOBCTL_TRAPPING_BIT, | |
368 | TASK_UNINTERRUPTIBLE); | |
369 | proc_ptrace_connector(task, PTRACE_ATTACH); | |
370 | } | |
371 | ||
372 | return retval; | |
373 | } | |
374 | ||
375 | /** | |
376 | * ptrace_traceme -- helper for PTRACE_TRACEME | |
377 | * | |
378 | * Performs checks and sets PT_PTRACED. | |
379 | * Should be used by all ptrace implementations for PTRACE_TRACEME. | |
380 | */ | |
381 | static int ptrace_traceme(void) | |
382 | { | |
383 | int ret = -EPERM; | |
384 | ||
385 | write_lock_irq(&tasklist_lock); | |
386 | /* Are we already being traced? */ | |
387 | if (!current->ptrace) { | |
388 | ret = security_ptrace_traceme(current->parent); | |
389 | /* | |
390 | * Check PF_EXITING to ensure ->real_parent has not passed | |
391 | * exit_ptrace(). Otherwise we don't report the error but | |
392 | * pretend ->real_parent untraces us right after return. | |
393 | */ | |
394 | if (!ret && !(current->real_parent->flags & PF_EXITING)) { | |
395 | current->ptrace = PT_PTRACED; | |
396 | __ptrace_link(current, current->real_parent); | |
397 | } | |
398 | } | |
399 | write_unlock_irq(&tasklist_lock); | |
400 | ||
401 | return ret; | |
402 | } | |
403 | ||
404 | /* | |
405 | * Called with irqs disabled, returns true if childs should reap themselves. | |
406 | */ | |
407 | static int ignoring_children(struct sighand_struct *sigh) | |
408 | { | |
409 | int ret; | |
410 | spin_lock(&sigh->siglock); | |
411 | ret = (sigh->action[SIGCHLD-1].sa.sa_handler == SIG_IGN) || | |
412 | (sigh->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT); | |
413 | spin_unlock(&sigh->siglock); | |
414 | return ret; | |
415 | } | |
416 | ||
417 | /* | |
418 | * Called with tasklist_lock held for writing. | |
419 | * Unlink a traced task, and clean it up if it was a traced zombie. | |
420 | * Return true if it needs to be reaped with release_task(). | |
421 | * (We can't call release_task() here because we already hold tasklist_lock.) | |
422 | * | |
423 | * If it's a zombie, our attachedness prevented normal parent notification | |
424 | * or self-reaping. Do notification now if it would have happened earlier. | |
425 | * If it should reap itself, return true. | |
426 | * | |
427 | * If it's our own child, there is no notification to do. But if our normal | |
428 | * children self-reap, then this child was prevented by ptrace and we must | |
429 | * reap it now, in that case we must also wake up sub-threads sleeping in | |
430 | * do_wait(). | |
431 | */ | |
432 | static bool __ptrace_detach(struct task_struct *tracer, struct task_struct *p) | |
433 | { | |
434 | bool dead; | |
435 | ||
436 | __ptrace_unlink(p); | |
437 | ||
438 | if (p->exit_state != EXIT_ZOMBIE) | |
439 | return false; | |
440 | ||
441 | dead = !thread_group_leader(p); | |
442 | ||
443 | if (!dead && thread_group_empty(p)) { | |
444 | if (!same_thread_group(p->real_parent, tracer)) | |
445 | dead = do_notify_parent(p, p->exit_signal); | |
446 | else if (ignoring_children(tracer->sighand)) { | |
447 | __wake_up_parent(p, tracer); | |
448 | dead = true; | |
449 | } | |
450 | } | |
451 | /* Mark it as in the process of being reaped. */ | |
452 | if (dead) | |
453 | p->exit_state = EXIT_DEAD; | |
454 | return dead; | |
455 | } | |
456 | ||
457 | static int ptrace_detach(struct task_struct *child, unsigned int data) | |
458 | { | |
459 | if (!valid_signal(data)) | |
460 | return -EIO; | |
461 | ||
462 | /* Architecture-specific hardware disable .. */ | |
463 | ptrace_disable(child); | |
464 | clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); | |
465 | ||
466 | write_lock_irq(&tasklist_lock); | |
467 | /* | |
468 | * We rely on ptrace_freeze_traced(). It can't be killed and | |
469 | * untraced by another thread, it can't be a zombie. | |
470 | */ | |
471 | WARN_ON(!child->ptrace || child->exit_state); | |
472 | /* | |
473 | * tasklist_lock avoids the race with wait_task_stopped(), see | |
474 | * the comment in ptrace_resume(). | |
475 | */ | |
476 | child->exit_code = data; | |
477 | __ptrace_detach(current, child); | |
478 | write_unlock_irq(&tasklist_lock); | |
479 | ||
480 | proc_ptrace_connector(child, PTRACE_DETACH); | |
481 | ||
482 | return 0; | |
483 | } | |
484 | ||
485 | /* | |
486 | * Detach all tasks we were using ptrace on. Called with tasklist held | |
487 | * for writing. | |
488 | */ | |
489 | void exit_ptrace(struct task_struct *tracer, struct list_head *dead) | |
490 | { | |
491 | struct task_struct *p, *n; | |
492 | ||
493 | list_for_each_entry_safe(p, n, &tracer->ptraced, ptrace_entry) { | |
494 | if (unlikely(p->ptrace & PT_EXITKILL)) | |
495 | send_sig_info(SIGKILL, SEND_SIG_FORCED, p); | |
496 | ||
497 | if (__ptrace_detach(tracer, p)) | |
498 | list_add(&p->ptrace_entry, dead); | |
499 | } | |
500 | } | |
501 | ||
502 | int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len) | |
503 | { | |
504 | int copied = 0; | |
505 | ||
506 | while (len > 0) { | |
507 | char buf[128]; | |
508 | int this_len, retval; | |
509 | ||
510 | this_len = (len > sizeof(buf)) ? sizeof(buf) : len; | |
511 | retval = access_process_vm(tsk, src, buf, this_len, 0); | |
512 | if (!retval) { | |
513 | if (copied) | |
514 | break; | |
515 | return -EIO; | |
516 | } | |
517 | if (copy_to_user(dst, buf, retval)) | |
518 | return -EFAULT; | |
519 | copied += retval; | |
520 | src += retval; | |
521 | dst += retval; | |
522 | len -= retval; | |
523 | } | |
524 | return copied; | |
525 | } | |
526 | ||
527 | int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len) | |
528 | { | |
529 | int copied = 0; | |
530 | ||
531 | while (len > 0) { | |
532 | char buf[128]; | |
533 | int this_len, retval; | |
534 | ||
535 | this_len = (len > sizeof(buf)) ? sizeof(buf) : len; | |
536 | if (copy_from_user(buf, src, this_len)) | |
537 | return -EFAULT; | |
538 | retval = access_process_vm(tsk, dst, buf, this_len, 1); | |
539 | if (!retval) { | |
540 | if (copied) | |
541 | break; | |
542 | return -EIO; | |
543 | } | |
544 | copied += retval; | |
545 | src += retval; | |
546 | dst += retval; | |
547 | len -= retval; | |
548 | } | |
549 | return copied; | |
550 | } | |
551 | ||
552 | static int ptrace_setoptions(struct task_struct *child, unsigned long data) | |
553 | { | |
554 | unsigned flags; | |
555 | ||
556 | if (data & ~(unsigned long)PTRACE_O_MASK) | |
557 | return -EINVAL; | |
558 | ||
559 | if (unlikely(data & PTRACE_O_SUSPEND_SECCOMP)) { | |
560 | if (!config_enabled(CONFIG_CHECKPOINT_RESTORE) || | |
561 | !config_enabled(CONFIG_SECCOMP)) | |
562 | return -EINVAL; | |
563 | ||
564 | if (!capable(CAP_SYS_ADMIN)) | |
565 | return -EPERM; | |
566 | ||
567 | if (seccomp_mode(¤t->seccomp) != SECCOMP_MODE_DISABLED || | |
568 | current->ptrace & PT_SUSPEND_SECCOMP) | |
569 | return -EPERM; | |
570 | } | |
571 | ||
572 | /* Avoid intermediate state when all opts are cleared */ | |
573 | flags = child->ptrace; | |
574 | flags &= ~(PTRACE_O_MASK << PT_OPT_FLAG_SHIFT); | |
575 | flags |= (data << PT_OPT_FLAG_SHIFT); | |
576 | child->ptrace = flags; | |
577 | ||
578 | return 0; | |
579 | } | |
580 | ||
581 | static int ptrace_getsiginfo(struct task_struct *child, siginfo_t *info) | |
582 | { | |
583 | unsigned long flags; | |
584 | int error = -ESRCH; | |
585 | ||
586 | if (lock_task_sighand(child, &flags)) { | |
587 | error = -EINVAL; | |
588 | if (likely(child->last_siginfo != NULL)) { | |
589 | *info = *child->last_siginfo; | |
590 | error = 0; | |
591 | } | |
592 | unlock_task_sighand(child, &flags); | |
593 | } | |
594 | return error; | |
595 | } | |
596 | ||
597 | static int ptrace_setsiginfo(struct task_struct *child, const siginfo_t *info) | |
598 | { | |
599 | unsigned long flags; | |
600 | int error = -ESRCH; | |
601 | ||
602 | if (lock_task_sighand(child, &flags)) { | |
603 | error = -EINVAL; | |
604 | if (likely(child->last_siginfo != NULL)) { | |
605 | *child->last_siginfo = *info; | |
606 | error = 0; | |
607 | } | |
608 | unlock_task_sighand(child, &flags); | |
609 | } | |
610 | return error; | |
611 | } | |
612 | ||
613 | static int ptrace_peek_siginfo(struct task_struct *child, | |
614 | unsigned long addr, | |
615 | unsigned long data) | |
616 | { | |
617 | struct ptrace_peeksiginfo_args arg; | |
618 | struct sigpending *pending; | |
619 | struct sigqueue *q; | |
620 | int ret, i; | |
621 | ||
622 | ret = copy_from_user(&arg, (void __user *) addr, | |
623 | sizeof(struct ptrace_peeksiginfo_args)); | |
624 | if (ret) | |
625 | return -EFAULT; | |
626 | ||
627 | if (arg.flags & ~PTRACE_PEEKSIGINFO_SHARED) | |
628 | return -EINVAL; /* unknown flags */ | |
629 | ||
630 | if (arg.nr < 0) | |
631 | return -EINVAL; | |
632 | ||
633 | if (arg.flags & PTRACE_PEEKSIGINFO_SHARED) | |
634 | pending = &child->signal->shared_pending; | |
635 | else | |
636 | pending = &child->pending; | |
637 | ||
638 | for (i = 0; i < arg.nr; ) { | |
639 | siginfo_t info; | |
640 | s32 off = arg.off + i; | |
641 | ||
642 | spin_lock_irq(&child->sighand->siglock); | |
643 | list_for_each_entry(q, &pending->list, list) { | |
644 | if (!off--) { | |
645 | copy_siginfo(&info, &q->info); | |
646 | break; | |
647 | } | |
648 | } | |
649 | spin_unlock_irq(&child->sighand->siglock); | |
650 | ||
651 | if (off >= 0) /* beyond the end of the list */ | |
652 | break; | |
653 | ||
654 | #ifdef CONFIG_COMPAT | |
655 | if (unlikely(is_compat_task())) { | |
656 | compat_siginfo_t __user *uinfo = compat_ptr(data); | |
657 | ||
658 | if (copy_siginfo_to_user32(uinfo, &info) || | |
659 | __put_user(info.si_code, &uinfo->si_code)) { | |
660 | ret = -EFAULT; | |
661 | break; | |
662 | } | |
663 | ||
664 | } else | |
665 | #endif | |
666 | { | |
667 | siginfo_t __user *uinfo = (siginfo_t __user *) data; | |
668 | ||
669 | if (copy_siginfo_to_user(uinfo, &info) || | |
670 | __put_user(info.si_code, &uinfo->si_code)) { | |
671 | ret = -EFAULT; | |
672 | break; | |
673 | } | |
674 | } | |
675 | ||
676 | data += sizeof(siginfo_t); | |
677 | i++; | |
678 | ||
679 | if (signal_pending(current)) | |
680 | break; | |
681 | ||
682 | cond_resched(); | |
683 | } | |
684 | ||
685 | if (i > 0) | |
686 | return i; | |
687 | ||
688 | return ret; | |
689 | } | |
690 | ||
691 | #ifdef PTRACE_SINGLESTEP | |
692 | #define is_singlestep(request) ((request) == PTRACE_SINGLESTEP) | |
693 | #else | |
694 | #define is_singlestep(request) 0 | |
695 | #endif | |
696 | ||
697 | #ifdef PTRACE_SINGLEBLOCK | |
698 | #define is_singleblock(request) ((request) == PTRACE_SINGLEBLOCK) | |
699 | #else | |
700 | #define is_singleblock(request) 0 | |
701 | #endif | |
702 | ||
703 | #ifdef PTRACE_SYSEMU | |
704 | #define is_sysemu_singlestep(request) ((request) == PTRACE_SYSEMU_SINGLESTEP) | |
705 | #else | |
706 | #define is_sysemu_singlestep(request) 0 | |
707 | #endif | |
708 | ||
709 | static int ptrace_resume(struct task_struct *child, long request, | |
710 | unsigned long data) | |
711 | { | |
712 | bool need_siglock; | |
713 | ||
714 | if (!valid_signal(data)) | |
715 | return -EIO; | |
716 | ||
717 | if (request == PTRACE_SYSCALL) | |
718 | set_tsk_thread_flag(child, TIF_SYSCALL_TRACE); | |
719 | else | |
720 | clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); | |
721 | ||
722 | #ifdef TIF_SYSCALL_EMU | |
723 | if (request == PTRACE_SYSEMU || request == PTRACE_SYSEMU_SINGLESTEP) | |
724 | set_tsk_thread_flag(child, TIF_SYSCALL_EMU); | |
725 | else | |
726 | clear_tsk_thread_flag(child, TIF_SYSCALL_EMU); | |
727 | #endif | |
728 | ||
729 | if (is_singleblock(request)) { | |
730 | if (unlikely(!arch_has_block_step())) | |
731 | return -EIO; | |
732 | user_enable_block_step(child); | |
733 | } else if (is_singlestep(request) || is_sysemu_singlestep(request)) { | |
734 | if (unlikely(!arch_has_single_step())) | |
735 | return -EIO; | |
736 | user_enable_single_step(child); | |
737 | } else { | |
738 | user_disable_single_step(child); | |
739 | } | |
740 | ||
741 | /* | |
742 | * Change ->exit_code and ->state under siglock to avoid the race | |
743 | * with wait_task_stopped() in between; a non-zero ->exit_code will | |
744 | * wrongly look like another report from tracee. | |
745 | * | |
746 | * Note that we need siglock even if ->exit_code == data and/or this | |
747 | * status was not reported yet, the new status must not be cleared by | |
748 | * wait_task_stopped() after resume. | |
749 | * | |
750 | * If data == 0 we do not care if wait_task_stopped() reports the old | |
751 | * status and clears the code too; this can't race with the tracee, it | |
752 | * takes siglock after resume. | |
753 | */ | |
754 | need_siglock = data && !thread_group_empty(current); | |
755 | if (need_siglock) | |
756 | spin_lock_irq(&child->sighand->siglock); | |
757 | child->exit_code = data; | |
758 | wake_up_state(child, __TASK_TRACED); | |
759 | if (need_siglock) | |
760 | spin_unlock_irq(&child->sighand->siglock); | |
761 | ||
762 | return 0; | |
763 | } | |
764 | ||
765 | #ifdef CONFIG_HAVE_ARCH_TRACEHOOK | |
766 | ||
767 | static const struct user_regset * | |
768 | find_regset(const struct user_regset_view *view, unsigned int type) | |
769 | { | |
770 | const struct user_regset *regset; | |
771 | int n; | |
772 | ||
773 | for (n = 0; n < view->n; ++n) { | |
774 | regset = view->regsets + n; | |
775 | if (regset->core_note_type == type) | |
776 | return regset; | |
777 | } | |
778 | ||
779 | return NULL; | |
780 | } | |
781 | ||
782 | static int ptrace_regset(struct task_struct *task, int req, unsigned int type, | |
783 | struct iovec *kiov) | |
784 | { | |
785 | const struct user_regset_view *view = task_user_regset_view(task); | |
786 | const struct user_regset *regset = find_regset(view, type); | |
787 | int regset_no; | |
788 | ||
789 | if (!regset || (kiov->iov_len % regset->size) != 0) | |
790 | return -EINVAL; | |
791 | ||
792 | regset_no = regset - view->regsets; | |
793 | kiov->iov_len = min(kiov->iov_len, | |
794 | (__kernel_size_t) (regset->n * regset->size)); | |
795 | ||
796 | if (req == PTRACE_GETREGSET) | |
797 | return copy_regset_to_user(task, view, regset_no, 0, | |
798 | kiov->iov_len, kiov->iov_base); | |
799 | else | |
800 | return copy_regset_from_user(task, view, regset_no, 0, | |
801 | kiov->iov_len, kiov->iov_base); | |
802 | } | |
803 | ||
804 | /* | |
805 | * This is declared in linux/regset.h and defined in machine-dependent | |
806 | * code. We put the export here, near the primary machine-neutral use, | |
807 | * to ensure no machine forgets it. | |
808 | */ | |
809 | EXPORT_SYMBOL_GPL(task_user_regset_view); | |
810 | #endif | |
811 | ||
812 | int ptrace_request(struct task_struct *child, long request, | |
813 | unsigned long addr, unsigned long data) | |
814 | { | |
815 | bool seized = child->ptrace & PT_SEIZED; | |
816 | int ret = -EIO; | |
817 | siginfo_t siginfo, *si; | |
818 | void __user *datavp = (void __user *) data; | |
819 | unsigned long __user *datalp = datavp; | |
820 | unsigned long flags; | |
821 | ||
822 | switch (request) { | |
823 | case PTRACE_PEEKTEXT: | |
824 | case PTRACE_PEEKDATA: | |
825 | return generic_ptrace_peekdata(child, addr, data); | |
826 | case PTRACE_POKETEXT: | |
827 | case PTRACE_POKEDATA: | |
828 | return generic_ptrace_pokedata(child, addr, data); | |
829 | ||
830 | #ifdef PTRACE_OLDSETOPTIONS | |
831 | case PTRACE_OLDSETOPTIONS: | |
832 | #endif | |
833 | case PTRACE_SETOPTIONS: | |
834 | ret = ptrace_setoptions(child, data); | |
835 | break; | |
836 | case PTRACE_GETEVENTMSG: | |
837 | ret = put_user(child->ptrace_message, datalp); | |
838 | break; | |
839 | ||
840 | case PTRACE_PEEKSIGINFO: | |
841 | ret = ptrace_peek_siginfo(child, addr, data); | |
842 | break; | |
843 | ||
844 | case PTRACE_GETSIGINFO: | |
845 | ret = ptrace_getsiginfo(child, &siginfo); | |
846 | if (!ret) | |
847 | ret = copy_siginfo_to_user(datavp, &siginfo); | |
848 | break; | |
849 | ||
850 | case PTRACE_SETSIGINFO: | |
851 | if (copy_from_user(&siginfo, datavp, sizeof siginfo)) | |
852 | ret = -EFAULT; | |
853 | else | |
854 | ret = ptrace_setsiginfo(child, &siginfo); | |
855 | break; | |
856 | ||
857 | case PTRACE_GETSIGMASK: | |
858 | if (addr != sizeof(sigset_t)) { | |
859 | ret = -EINVAL; | |
860 | break; | |
861 | } | |
862 | ||
863 | if (copy_to_user(datavp, &child->blocked, sizeof(sigset_t))) | |
864 | ret = -EFAULT; | |
865 | else | |
866 | ret = 0; | |
867 | ||
868 | break; | |
869 | ||
870 | case PTRACE_SETSIGMASK: { | |
871 | sigset_t new_set; | |
872 | ||
873 | if (addr != sizeof(sigset_t)) { | |
874 | ret = -EINVAL; | |
875 | break; | |
876 | } | |
877 | ||
878 | if (copy_from_user(&new_set, datavp, sizeof(sigset_t))) { | |
879 | ret = -EFAULT; | |
880 | break; | |
881 | } | |
882 | ||
883 | sigdelsetmask(&new_set, sigmask(SIGKILL)|sigmask(SIGSTOP)); | |
884 | ||
885 | /* | |
886 | * Every thread does recalc_sigpending() after resume, so | |
887 | * retarget_shared_pending() and recalc_sigpending() are not | |
888 | * called here. | |
889 | */ | |
890 | spin_lock_irq(&child->sighand->siglock); | |
891 | child->blocked = new_set; | |
892 | spin_unlock_irq(&child->sighand->siglock); | |
893 | ||
894 | ret = 0; | |
895 | break; | |
896 | } | |
897 | ||
898 | case PTRACE_INTERRUPT: | |
899 | /* | |
900 | * Stop tracee without any side-effect on signal or job | |
901 | * control. At least one trap is guaranteed to happen | |
902 | * after this request. If @child is already trapped, the | |
903 | * current trap is not disturbed and another trap will | |
904 | * happen after the current trap is ended with PTRACE_CONT. | |
905 | * | |
906 | * The actual trap might not be PTRACE_EVENT_STOP trap but | |
907 | * the pending condition is cleared regardless. | |
908 | */ | |
909 | if (unlikely(!seized || !lock_task_sighand(child, &flags))) | |
910 | break; | |
911 | ||
912 | /* | |
913 | * INTERRUPT doesn't disturb existing trap sans one | |
914 | * exception. If ptracer issued LISTEN for the current | |
915 | * STOP, this INTERRUPT should clear LISTEN and re-trap | |
916 | * tracee into STOP. | |
917 | */ | |
918 | if (likely(task_set_jobctl_pending(child, JOBCTL_TRAP_STOP))) | |
919 | ptrace_signal_wake_up(child, child->jobctl & JOBCTL_LISTENING); | |
920 | ||
921 | unlock_task_sighand(child, &flags); | |
922 | ret = 0; | |
923 | break; | |
924 | ||
925 | case PTRACE_LISTEN: | |
926 | /* | |
927 | * Listen for events. Tracee must be in STOP. It's not | |
928 | * resumed per-se but is not considered to be in TRACED by | |
929 | * wait(2) or ptrace(2). If an async event (e.g. group | |
930 | * stop state change) happens, tracee will enter STOP trap | |
931 | * again. Alternatively, ptracer can issue INTERRUPT to | |
932 | * finish listening and re-trap tracee into STOP. | |
933 | */ | |
934 | if (unlikely(!seized || !lock_task_sighand(child, &flags))) | |
935 | break; | |
936 | ||
937 | si = child->last_siginfo; | |
938 | if (likely(si && (si->si_code >> 8) == PTRACE_EVENT_STOP)) { | |
939 | child->jobctl |= JOBCTL_LISTENING; | |
940 | /* | |
941 | * If NOTIFY is set, it means event happened between | |
942 | * start of this trap and now. Trigger re-trap. | |
943 | */ | |
944 | if (child->jobctl & JOBCTL_TRAP_NOTIFY) | |
945 | ptrace_signal_wake_up(child, true); | |
946 | ret = 0; | |
947 | } | |
948 | unlock_task_sighand(child, &flags); | |
949 | break; | |
950 | ||
951 | case PTRACE_DETACH: /* detach a process that was attached. */ | |
952 | ret = ptrace_detach(child, data); | |
953 | break; | |
954 | ||
955 | #ifdef CONFIG_BINFMT_ELF_FDPIC | |
956 | case PTRACE_GETFDPIC: { | |
957 | struct mm_struct *mm = get_task_mm(child); | |
958 | unsigned long tmp = 0; | |
959 | ||
960 | ret = -ESRCH; | |
961 | if (!mm) | |
962 | break; | |
963 | ||
964 | switch (addr) { | |
965 | case PTRACE_GETFDPIC_EXEC: | |
966 | tmp = mm->context.exec_fdpic_loadmap; | |
967 | break; | |
968 | case PTRACE_GETFDPIC_INTERP: | |
969 | tmp = mm->context.interp_fdpic_loadmap; | |
970 | break; | |
971 | default: | |
972 | break; | |
973 | } | |
974 | mmput(mm); | |
975 | ||
976 | ret = put_user(tmp, datalp); | |
977 | break; | |
978 | } | |
979 | #endif | |
980 | ||
981 | #ifdef PTRACE_SINGLESTEP | |
982 | case PTRACE_SINGLESTEP: | |
983 | #endif | |
984 | #ifdef PTRACE_SINGLEBLOCK | |
985 | case PTRACE_SINGLEBLOCK: | |
986 | #endif | |
987 | #ifdef PTRACE_SYSEMU | |
988 | case PTRACE_SYSEMU: | |
989 | case PTRACE_SYSEMU_SINGLESTEP: | |
990 | #endif | |
991 | case PTRACE_SYSCALL: | |
992 | case PTRACE_CONT: | |
993 | return ptrace_resume(child, request, data); | |
994 | ||
995 | case PTRACE_KILL: | |
996 | if (child->exit_state) /* already dead */ | |
997 | return 0; | |
998 | return ptrace_resume(child, request, SIGKILL); | |
999 | ||
1000 | #ifdef CONFIG_HAVE_ARCH_TRACEHOOK | |
1001 | case PTRACE_GETREGSET: | |
1002 | case PTRACE_SETREGSET: { | |
1003 | struct iovec kiov; | |
1004 | struct iovec __user *uiov = datavp; | |
1005 | ||
1006 | if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov))) | |
1007 | return -EFAULT; | |
1008 | ||
1009 | if (__get_user(kiov.iov_base, &uiov->iov_base) || | |
1010 | __get_user(kiov.iov_len, &uiov->iov_len)) | |
1011 | return -EFAULT; | |
1012 | ||
1013 | ret = ptrace_regset(child, request, addr, &kiov); | |
1014 | if (!ret) | |
1015 | ret = __put_user(kiov.iov_len, &uiov->iov_len); | |
1016 | break; | |
1017 | } | |
1018 | #endif | |
1019 | ||
1020 | case PTRACE_SECCOMP_GET_FILTER: | |
1021 | ret = seccomp_get_filter(child, addr, datavp); | |
1022 | break; | |
1023 | ||
1024 | default: | |
1025 | break; | |
1026 | } | |
1027 | ||
1028 | return ret; | |
1029 | } | |
1030 | ||
1031 | static struct task_struct *ptrace_get_task_struct(pid_t pid) | |
1032 | { | |
1033 | struct task_struct *child; | |
1034 | ||
1035 | rcu_read_lock(); | |
1036 | child = find_task_by_vpid(pid); | |
1037 | if (child) | |
1038 | get_task_struct(child); | |
1039 | rcu_read_unlock(); | |
1040 | ||
1041 | if (!child) | |
1042 | return ERR_PTR(-ESRCH); | |
1043 | return child; | |
1044 | } | |
1045 | ||
1046 | #ifndef arch_ptrace_attach | |
1047 | #define arch_ptrace_attach(child) do { } while (0) | |
1048 | #endif | |
1049 | ||
1050 | SYSCALL_DEFINE4(ptrace, long, request, long, pid, unsigned long, addr, | |
1051 | unsigned long, data) | |
1052 | { | |
1053 | struct task_struct *child; | |
1054 | long ret; | |
1055 | ||
1056 | if (request == PTRACE_TRACEME) { | |
1057 | ret = ptrace_traceme(); | |
1058 | if (!ret) | |
1059 | arch_ptrace_attach(current); | |
1060 | goto out; | |
1061 | } | |
1062 | ||
1063 | child = ptrace_get_task_struct(pid); | |
1064 | if (IS_ERR(child)) { | |
1065 | ret = PTR_ERR(child); | |
1066 | goto out; | |
1067 | } | |
1068 | ||
1069 | if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) { | |
1070 | ret = ptrace_attach(child, request, addr, data); | |
1071 | /* | |
1072 | * Some architectures need to do book-keeping after | |
1073 | * a ptrace attach. | |
1074 | */ | |
1075 | if (!ret) | |
1076 | arch_ptrace_attach(child); | |
1077 | goto out_put_task_struct; | |
1078 | } | |
1079 | ||
1080 | ret = ptrace_check_attach(child, request == PTRACE_KILL || | |
1081 | request == PTRACE_INTERRUPT); | |
1082 | if (ret < 0) | |
1083 | goto out_put_task_struct; | |
1084 | ||
1085 | ret = arch_ptrace(child, request, addr, data); | |
1086 | if (ret || request != PTRACE_DETACH) | |
1087 | ptrace_unfreeze_traced(child); | |
1088 | ||
1089 | out_put_task_struct: | |
1090 | put_task_struct(child); | |
1091 | out: | |
1092 | return ret; | |
1093 | } | |
1094 | ||
1095 | int generic_ptrace_peekdata(struct task_struct *tsk, unsigned long addr, | |
1096 | unsigned long data) | |
1097 | { | |
1098 | unsigned long tmp; | |
1099 | int copied; | |
1100 | ||
1101 | copied = access_process_vm(tsk, addr, &tmp, sizeof(tmp), 0); | |
1102 | if (copied != sizeof(tmp)) | |
1103 | return -EIO; | |
1104 | return put_user(tmp, (unsigned long __user *)data); | |
1105 | } | |
1106 | ||
1107 | int generic_ptrace_pokedata(struct task_struct *tsk, unsigned long addr, | |
1108 | unsigned long data) | |
1109 | { | |
1110 | int copied; | |
1111 | ||
1112 | copied = access_process_vm(tsk, addr, &data, sizeof(data), 1); | |
1113 | return (copied == sizeof(data)) ? 0 : -EIO; | |
1114 | } | |
1115 | ||
1116 | #if defined CONFIG_COMPAT | |
1117 | ||
1118 | int compat_ptrace_request(struct task_struct *child, compat_long_t request, | |
1119 | compat_ulong_t addr, compat_ulong_t data) | |
1120 | { | |
1121 | compat_ulong_t __user *datap = compat_ptr(data); | |
1122 | compat_ulong_t word; | |
1123 | siginfo_t siginfo; | |
1124 | int ret; | |
1125 | ||
1126 | switch (request) { | |
1127 | case PTRACE_PEEKTEXT: | |
1128 | case PTRACE_PEEKDATA: | |
1129 | ret = access_process_vm(child, addr, &word, sizeof(word), 0); | |
1130 | if (ret != sizeof(word)) | |
1131 | ret = -EIO; | |
1132 | else | |
1133 | ret = put_user(word, datap); | |
1134 | break; | |
1135 | ||
1136 | case PTRACE_POKETEXT: | |
1137 | case PTRACE_POKEDATA: | |
1138 | ret = access_process_vm(child, addr, &data, sizeof(data), 1); | |
1139 | ret = (ret != sizeof(data) ? -EIO : 0); | |
1140 | break; | |
1141 | ||
1142 | case PTRACE_GETEVENTMSG: | |
1143 | ret = put_user((compat_ulong_t) child->ptrace_message, datap); | |
1144 | break; | |
1145 | ||
1146 | case PTRACE_GETSIGINFO: | |
1147 | ret = ptrace_getsiginfo(child, &siginfo); | |
1148 | if (!ret) | |
1149 | ret = copy_siginfo_to_user32( | |
1150 | (struct compat_siginfo __user *) datap, | |
1151 | &siginfo); | |
1152 | break; | |
1153 | ||
1154 | case PTRACE_SETSIGINFO: | |
1155 | memset(&siginfo, 0, sizeof siginfo); | |
1156 | if (copy_siginfo_from_user32( | |
1157 | &siginfo, (struct compat_siginfo __user *) datap)) | |
1158 | ret = -EFAULT; | |
1159 | else | |
1160 | ret = ptrace_setsiginfo(child, &siginfo); | |
1161 | break; | |
1162 | #ifdef CONFIG_HAVE_ARCH_TRACEHOOK | |
1163 | case PTRACE_GETREGSET: | |
1164 | case PTRACE_SETREGSET: | |
1165 | { | |
1166 | struct iovec kiov; | |
1167 | struct compat_iovec __user *uiov = | |
1168 | (struct compat_iovec __user *) datap; | |
1169 | compat_uptr_t ptr; | |
1170 | compat_size_t len; | |
1171 | ||
1172 | if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov))) | |
1173 | return -EFAULT; | |
1174 | ||
1175 | if (__get_user(ptr, &uiov->iov_base) || | |
1176 | __get_user(len, &uiov->iov_len)) | |
1177 | return -EFAULT; | |
1178 | ||
1179 | kiov.iov_base = compat_ptr(ptr); | |
1180 | kiov.iov_len = len; | |
1181 | ||
1182 | ret = ptrace_regset(child, request, addr, &kiov); | |
1183 | if (!ret) | |
1184 | ret = __put_user(kiov.iov_len, &uiov->iov_len); | |
1185 | break; | |
1186 | } | |
1187 | #endif | |
1188 | ||
1189 | default: | |
1190 | ret = ptrace_request(child, request, addr, data); | |
1191 | } | |
1192 | ||
1193 | return ret; | |
1194 | } | |
1195 | ||
1196 | COMPAT_SYSCALL_DEFINE4(ptrace, compat_long_t, request, compat_long_t, pid, | |
1197 | compat_long_t, addr, compat_long_t, data) | |
1198 | { | |
1199 | struct task_struct *child; | |
1200 | long ret; | |
1201 | ||
1202 | if (request == PTRACE_TRACEME) { | |
1203 | ret = ptrace_traceme(); | |
1204 | goto out; | |
1205 | } | |
1206 | ||
1207 | child = ptrace_get_task_struct(pid); | |
1208 | if (IS_ERR(child)) { | |
1209 | ret = PTR_ERR(child); | |
1210 | goto out; | |
1211 | } | |
1212 | ||
1213 | if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) { | |
1214 | ret = ptrace_attach(child, request, addr, data); | |
1215 | /* | |
1216 | * Some architectures need to do book-keeping after | |
1217 | * a ptrace attach. | |
1218 | */ | |
1219 | if (!ret) | |
1220 | arch_ptrace_attach(child); | |
1221 | goto out_put_task_struct; | |
1222 | } | |
1223 | ||
1224 | ret = ptrace_check_attach(child, request == PTRACE_KILL || | |
1225 | request == PTRACE_INTERRUPT); | |
1226 | if (!ret) { | |
1227 | ret = compat_arch_ptrace(child, request, addr, data); | |
1228 | if (ret || request != PTRACE_DETACH) | |
1229 | ptrace_unfreeze_traced(child); | |
1230 | } | |
1231 | ||
1232 | out_put_task_struct: | |
1233 | put_task_struct(child); | |
1234 | out: | |
1235 | return ret; | |
1236 | } | |
1237 | #endif /* CONFIG_COMPAT */ |