Commit | Line | Data |
---|---|---|
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> |
bf26c018 | 25 | #include <linux/hw_breakpoint.h> |
1da177e4 | 26 | |
bf53de90 | 27 | |
62c124ff TH |
28 | static int ptrace_trapping_sleep_fn(void *flags) |
29 | { | |
30 | schedule(); | |
31 | return 0; | |
32 | } | |
33 | ||
1da177e4 LT |
34 | /* |
35 | * ptrace a task: make the debugger its new parent and | |
36 | * move it to the ptrace list. | |
37 | * | |
38 | * Must be called with the tasklist lock write-held. | |
39 | */ | |
36c8b586 | 40 | void __ptrace_link(struct task_struct *child, struct task_struct *new_parent) |
1da177e4 | 41 | { |
f470021a RM |
42 | BUG_ON(!list_empty(&child->ptrace_entry)); |
43 | list_add(&child->ptrace_entry, &new_parent->ptraced); | |
1da177e4 | 44 | child->parent = new_parent; |
1da177e4 | 45 | } |
3a709703 | 46 | |
e3bd058f TH |
47 | /** |
48 | * __ptrace_unlink - unlink ptracee and restore its execution state | |
49 | * @child: ptracee to be unlinked | |
1da177e4 | 50 | * |
0e9f0a4a TH |
51 | * Remove @child from the ptrace list, move it back to the original parent, |
52 | * and restore the execution state so that it conforms to the group stop | |
53 | * state. | |
54 | * | |
55 | * Unlinking can happen via two paths - explicit PTRACE_DETACH or ptracer | |
56 | * exiting. For PTRACE_DETACH, unless the ptracee has been killed between | |
57 | * ptrace_check_attach() and here, it's guaranteed to be in TASK_TRACED. | |
58 | * If the ptracer is exiting, the ptracee can be in any state. | |
59 | * | |
60 | * After detach, the ptracee should be in a state which conforms to the | |
61 | * group stop. If the group is stopped or in the process of stopping, the | |
62 | * ptracee should be put into TASK_STOPPED; otherwise, it should be woken | |
63 | * up from TASK_TRACED. | |
64 | * | |
65 | * If the ptracee is in TASK_TRACED and needs to be moved to TASK_STOPPED, | |
66 | * it goes through TRACED -> RUNNING -> STOPPED transition which is similar | |
67 | * to but in the opposite direction of what happens while attaching to a | |
68 | * stopped task. However, in this direction, the intermediate RUNNING | |
69 | * state is not hidden even from the current ptracer and if it immediately | |
70 | * re-attaches and performs a WNOHANG wait(2), it may fail. | |
e3bd058f TH |
71 | * |
72 | * CONTEXT: | |
73 | * write_lock_irq(tasklist_lock) | |
1da177e4 | 74 | */ |
36c8b586 | 75 | void __ptrace_unlink(struct task_struct *child) |
1da177e4 | 76 | { |
5ecfbae0 ON |
77 | BUG_ON(!child->ptrace); |
78 | ||
1da177e4 | 79 | child->ptrace = 0; |
f470021a RM |
80 | child->parent = child->real_parent; |
81 | list_del_init(&child->ptrace_entry); | |
1da177e4 | 82 | |
1da177e4 | 83 | spin_lock(&child->sighand->siglock); |
0e9f0a4a TH |
84 | |
85 | /* | |
a8f072c1 | 86 | * Reinstate JOBCTL_STOP_PENDING if group stop is in effect and |
0e9f0a4a TH |
87 | * @child isn't dead. |
88 | */ | |
89 | if (!(child->flags & PF_EXITING) && | |
90 | (child->signal->flags & SIGNAL_STOP_STOPPED || | |
91 | child->signal->group_stop_count)) | |
a8f072c1 | 92 | child->jobctl |= JOBCTL_STOP_PENDING; |
0e9f0a4a TH |
93 | |
94 | /* | |
95 | * If transition to TASK_STOPPED is pending or in TASK_TRACED, kick | |
96 | * @child in the butt. Note that @resume should be used iff @child | |
97 | * is in TASK_TRACED; otherwise, we might unduly disrupt | |
98 | * TASK_KILLABLE sleeps. | |
99 | */ | |
a8f072c1 | 100 | if (child->jobctl & JOBCTL_STOP_PENDING || task_is_traced(child)) |
0e9f0a4a TH |
101 | signal_wake_up(child, task_is_traced(child)); |
102 | ||
1da177e4 | 103 | spin_unlock(&child->sighand->siglock); |
1da177e4 LT |
104 | } |
105 | ||
755e276b TH |
106 | /** |
107 | * ptrace_check_attach - check whether ptracee is ready for ptrace operation | |
108 | * @child: ptracee to check for | |
109 | * @ignore_state: don't check whether @child is currently %TASK_TRACED | |
110 | * | |
111 | * Check whether @child is being ptraced by %current and ready for further | |
112 | * ptrace operations. If @ignore_state is %false, @child also should be in | |
113 | * %TASK_TRACED state and on return the child is guaranteed to be traced | |
114 | * and not executing. If @ignore_state is %true, @child can be in any | |
115 | * state. | |
116 | * | |
117 | * CONTEXT: | |
118 | * Grabs and releases tasklist_lock and @child->sighand->siglock. | |
119 | * | |
120 | * RETURNS: | |
121 | * 0 on success, -ESRCH if %child is not ready. | |
1da177e4 | 122 | */ |
755e276b | 123 | int ptrace_check_attach(struct task_struct *child, bool ignore_state) |
1da177e4 LT |
124 | { |
125 | int ret = -ESRCH; | |
126 | ||
127 | /* | |
128 | * We take the read lock around doing both checks to close a | |
129 | * possible race where someone else was tracing our child and | |
130 | * detached between these two checks. After this locked check, | |
131 | * we are sure that this is our traced child and that can only | |
132 | * be changed by us so it's not changing right after this. | |
133 | */ | |
134 | read_lock(&tasklist_lock); | |
c0c0b649 | 135 | if ((child->ptrace & PT_PTRACED) && child->parent == current) { |
c0c0b649 ON |
136 | /* |
137 | * child->sighand can't be NULL, release_task() | |
138 | * does ptrace_unlink() before __exit_signal(). | |
139 | */ | |
1da177e4 | 140 | spin_lock_irq(&child->sighand->siglock); |
321fb561 | 141 | WARN_ON_ONCE(task_is_stopped(child)); |
755e276b | 142 | if (task_is_traced(child) || ignore_state) |
321fb561 | 143 | ret = 0; |
1da177e4 LT |
144 | spin_unlock_irq(&child->sighand->siglock); |
145 | } | |
146 | read_unlock(&tasklist_lock); | |
147 | ||
755e276b | 148 | if (!ret && !ignore_state) |
85ba2d86 | 149 | ret = wait_task_inactive(child, TASK_TRACED) ? 0 : -ESRCH; |
1da177e4 LT |
150 | |
151 | /* All systems go.. */ | |
152 | return ret; | |
153 | } | |
154 | ||
006ebb40 | 155 | int __ptrace_may_access(struct task_struct *task, unsigned int mode) |
ab8d11be | 156 | { |
c69e8d9c | 157 | const struct cred *cred = current_cred(), *tcred; |
b6dff3ec | 158 | |
df26c40e EB |
159 | /* May we inspect the given task? |
160 | * This check is used both for attaching with ptrace | |
161 | * and for allowing access to sensitive information in /proc. | |
162 | * | |
163 | * ptrace_attach denies several cases that /proc allows | |
164 | * because setting up the necessary parent/child relationship | |
165 | * or halting the specified task is impossible. | |
166 | */ | |
167 | int dumpable = 0; | |
168 | /* Don't let security modules deny introspection */ | |
169 | if (task == current) | |
170 | return 0; | |
c69e8d9c DH |
171 | rcu_read_lock(); |
172 | tcred = __task_cred(task); | |
8409cca7 SH |
173 | if (cred->user->user_ns == tcred->user->user_ns && |
174 | (cred->uid == tcred->euid && | |
175 | cred->uid == tcred->suid && | |
176 | cred->uid == tcred->uid && | |
177 | cred->gid == tcred->egid && | |
178 | cred->gid == tcred->sgid && | |
179 | cred->gid == tcred->gid)) | |
180 | goto ok; | |
181 | if (ns_capable(tcred->user->user_ns, CAP_SYS_PTRACE)) | |
182 | goto ok; | |
183 | rcu_read_unlock(); | |
184 | return -EPERM; | |
185 | ok: | |
c69e8d9c | 186 | rcu_read_unlock(); |
ab8d11be | 187 | smp_rmb(); |
df26c40e | 188 | if (task->mm) |
6c5d5238 | 189 | dumpable = get_dumpable(task->mm); |
8409cca7 | 190 | if (!dumpable && !task_ns_capable(task, CAP_SYS_PTRACE)) |
ab8d11be MS |
191 | return -EPERM; |
192 | ||
9e48858f | 193 | return security_ptrace_access_check(task, mode); |
ab8d11be MS |
194 | } |
195 | ||
006ebb40 | 196 | bool ptrace_may_access(struct task_struct *task, unsigned int mode) |
ab8d11be MS |
197 | { |
198 | int err; | |
199 | task_lock(task); | |
006ebb40 | 200 | err = __ptrace_may_access(task, mode); |
ab8d11be | 201 | task_unlock(task); |
3a709703 | 202 | return !err; |
ab8d11be MS |
203 | } |
204 | ||
e3e89cc5 | 205 | static int ptrace_attach(struct task_struct *task) |
1da177e4 LT |
206 | { |
207 | int retval; | |
f5b40e36 | 208 | |
a5cb013d AV |
209 | audit_ptrace(task); |
210 | ||
1da177e4 | 211 | retval = -EPERM; |
b79b7ba9 ON |
212 | if (unlikely(task->flags & PF_KTHREAD)) |
213 | goto out; | |
bac0abd6 | 214 | if (same_thread_group(task, current)) |
f5b40e36 LT |
215 | goto out; |
216 | ||
f2f0b00a ON |
217 | /* |
218 | * Protect exec's credential calculations against our interference; | |
5e751e99 DH |
219 | * interference; SUID, SGID and LSM creds get determined differently |
220 | * under ptrace. | |
d84f4f99 | 221 | */ |
793285fc | 222 | retval = -ERESTARTNOINTR; |
9b1bf12d | 223 | if (mutex_lock_interruptible(&task->signal->cred_guard_mutex)) |
d84f4f99 | 224 | goto out; |
f5b40e36 | 225 | |
4b105cbb | 226 | task_lock(task); |
006ebb40 | 227 | retval = __ptrace_may_access(task, PTRACE_MODE_ATTACH); |
4b105cbb | 228 | task_unlock(task); |
1da177e4 | 229 | if (retval) |
4b105cbb | 230 | goto unlock_creds; |
1da177e4 | 231 | |
4b105cbb | 232 | write_lock_irq(&tasklist_lock); |
b79b7ba9 ON |
233 | retval = -EPERM; |
234 | if (unlikely(task->exit_state)) | |
4b105cbb | 235 | goto unlock_tasklist; |
f2f0b00a | 236 | if (task->ptrace) |
4b105cbb | 237 | goto unlock_tasklist; |
b79b7ba9 | 238 | |
f2f0b00a | 239 | task->ptrace = PT_PTRACED; |
8409cca7 | 240 | if (task_ns_capable(task, CAP_SYS_PTRACE)) |
1da177e4 | 241 | task->ptrace |= PT_PTRACE_CAP; |
1da177e4 | 242 | |
1da177e4 | 243 | __ptrace_link(task, current); |
33e9fc7d | 244 | send_sig_info(SIGSTOP, SEND_SIG_FORCED, task); |
b79b7ba9 | 245 | |
d79fdd6d TH |
246 | spin_lock(&task->sighand->siglock); |
247 | ||
248 | /* | |
a8f072c1 | 249 | * If the task is already STOPPED, set JOBCTL_STOP_PENDING and |
d79fdd6d TH |
250 | * TRAPPING, and kick it so that it transits to TRACED. TRAPPING |
251 | * will be cleared if the child completes the transition or any | |
252 | * event which clears the group stop states happens. We'll wait | |
253 | * for the transition to complete before returning from this | |
254 | * function. | |
255 | * | |
256 | * This hides STOPPED -> RUNNING -> TRACED transition from the | |
257 | * attaching thread but a different thread in the same group can | |
258 | * still observe the transient RUNNING state. IOW, if another | |
259 | * thread's WNOHANG wait(2) on the stopped tracee races against | |
260 | * ATTACH, the wait(2) may fail due to the transient RUNNING. | |
261 | * | |
262 | * The following task_is_stopped() test is safe as both transitions | |
263 | * in and out of STOPPED are protected by siglock. | |
264 | */ | |
7dd3db54 TH |
265 | if (task_is_stopped(task) && |
266 | task_set_jobctl_pending(task, | |
267 | JOBCTL_STOP_PENDING | JOBCTL_TRAPPING)) | |
d79fdd6d | 268 | signal_wake_up(task, 1); |
d79fdd6d TH |
269 | |
270 | spin_unlock(&task->sighand->siglock); | |
271 | ||
b79b7ba9 | 272 | retval = 0; |
4b105cbb ON |
273 | unlock_tasklist: |
274 | write_unlock_irq(&tasklist_lock); | |
275 | unlock_creds: | |
9b1bf12d | 276 | mutex_unlock(&task->signal->cred_guard_mutex); |
f5b40e36 | 277 | out: |
0b1007c3 | 278 | if (!retval) |
62c124ff TH |
279 | wait_on_bit(&task->jobctl, JOBCTL_TRAPPING_BIT, |
280 | ptrace_trapping_sleep_fn, TASK_UNINTERRUPTIBLE); | |
1da177e4 LT |
281 | return retval; |
282 | } | |
283 | ||
f2f0b00a ON |
284 | /** |
285 | * ptrace_traceme -- helper for PTRACE_TRACEME | |
286 | * | |
287 | * Performs checks and sets PT_PTRACED. | |
288 | * Should be used by all ptrace implementations for PTRACE_TRACEME. | |
289 | */ | |
e3e89cc5 | 290 | static int ptrace_traceme(void) |
f2f0b00a ON |
291 | { |
292 | int ret = -EPERM; | |
293 | ||
4b105cbb ON |
294 | write_lock_irq(&tasklist_lock); |
295 | /* Are we already being traced? */ | |
f2f0b00a | 296 | if (!current->ptrace) { |
f2f0b00a | 297 | ret = security_ptrace_traceme(current->parent); |
f2f0b00a ON |
298 | /* |
299 | * Check PF_EXITING to ensure ->real_parent has not passed | |
300 | * exit_ptrace(). Otherwise we don't report the error but | |
301 | * pretend ->real_parent untraces us right after return. | |
302 | */ | |
303 | if (!ret && !(current->real_parent->flags & PF_EXITING)) { | |
304 | current->ptrace = PT_PTRACED; | |
305 | __ptrace_link(current, current->real_parent); | |
306 | } | |
f2f0b00a | 307 | } |
4b105cbb ON |
308 | write_unlock_irq(&tasklist_lock); |
309 | ||
f2f0b00a ON |
310 | return ret; |
311 | } | |
312 | ||
39c626ae ON |
313 | /* |
314 | * Called with irqs disabled, returns true if childs should reap themselves. | |
315 | */ | |
316 | static int ignoring_children(struct sighand_struct *sigh) | |
317 | { | |
318 | int ret; | |
319 | spin_lock(&sigh->siglock); | |
320 | ret = (sigh->action[SIGCHLD-1].sa.sa_handler == SIG_IGN) || | |
321 | (sigh->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT); | |
322 | spin_unlock(&sigh->siglock); | |
323 | return ret; | |
324 | } | |
325 | ||
326 | /* | |
327 | * Called with tasklist_lock held for writing. | |
328 | * Unlink a traced task, and clean it up if it was a traced zombie. | |
329 | * Return true if it needs to be reaped with release_task(). | |
330 | * (We can't call release_task() here because we already hold tasklist_lock.) | |
331 | * | |
332 | * If it's a zombie, our attachedness prevented normal parent notification | |
333 | * or self-reaping. Do notification now if it would have happened earlier. | |
334 | * If it should reap itself, return true. | |
335 | * | |
a7f0765e ON |
336 | * If it's our own child, there is no notification to do. But if our normal |
337 | * children self-reap, then this child was prevented by ptrace and we must | |
338 | * reap it now, in that case we must also wake up sub-threads sleeping in | |
339 | * do_wait(). | |
39c626ae ON |
340 | */ |
341 | static bool __ptrace_detach(struct task_struct *tracer, struct task_struct *p) | |
342 | { | |
343 | __ptrace_unlink(p); | |
344 | ||
345 | if (p->exit_state == EXIT_ZOMBIE) { | |
346 | if (!task_detached(p) && thread_group_empty(p)) { | |
347 | if (!same_thread_group(p->real_parent, tracer)) | |
348 | do_notify_parent(p, p->exit_signal); | |
a7f0765e ON |
349 | else if (ignoring_children(tracer->sighand)) { |
350 | __wake_up_parent(p, tracer); | |
39c626ae | 351 | p->exit_signal = -1; |
a7f0765e | 352 | } |
39c626ae ON |
353 | } |
354 | if (task_detached(p)) { | |
355 | /* Mark it as in the process of being reaped. */ | |
356 | p->exit_state = EXIT_DEAD; | |
357 | return true; | |
358 | } | |
359 | } | |
360 | ||
361 | return false; | |
362 | } | |
363 | ||
e3e89cc5 | 364 | static int ptrace_detach(struct task_struct *child, unsigned int data) |
1da177e4 | 365 | { |
39c626ae | 366 | bool dead = false; |
4576145c | 367 | |
7ed20e1a | 368 | if (!valid_signal(data)) |
5ecfbae0 | 369 | return -EIO; |
1da177e4 LT |
370 | |
371 | /* Architecture-specific hardware disable .. */ | |
372 | ptrace_disable(child); | |
7d941432 | 373 | clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); |
1da177e4 | 374 | |
95c3eb76 | 375 | write_lock_irq(&tasklist_lock); |
39c626ae ON |
376 | /* |
377 | * This child can be already killed. Make sure de_thread() or | |
378 | * our sub-thread doing do_wait() didn't do release_task() yet. | |
379 | */ | |
95c3eb76 ON |
380 | if (child->ptrace) { |
381 | child->exit_code = data; | |
4576145c | 382 | dead = __ptrace_detach(current, child); |
95c3eb76 | 383 | } |
1da177e4 LT |
384 | write_unlock_irq(&tasklist_lock); |
385 | ||
4576145c ON |
386 | if (unlikely(dead)) |
387 | release_task(child); | |
388 | ||
1da177e4 LT |
389 | return 0; |
390 | } | |
391 | ||
39c626ae | 392 | /* |
c7e49c14 ON |
393 | * Detach all tasks we were using ptrace on. Called with tasklist held |
394 | * for writing, and returns with it held too. But note it can release | |
395 | * and reacquire the lock. | |
39c626ae ON |
396 | */ |
397 | void exit_ptrace(struct task_struct *tracer) | |
c4b5ed25 NK |
398 | __releases(&tasklist_lock) |
399 | __acquires(&tasklist_lock) | |
39c626ae ON |
400 | { |
401 | struct task_struct *p, *n; | |
402 | LIST_HEAD(ptrace_dead); | |
403 | ||
c7e49c14 ON |
404 | if (likely(list_empty(&tracer->ptraced))) |
405 | return; | |
406 | ||
39c626ae ON |
407 | list_for_each_entry_safe(p, n, &tracer->ptraced, ptrace_entry) { |
408 | if (__ptrace_detach(tracer, p)) | |
409 | list_add(&p->ptrace_entry, &ptrace_dead); | |
410 | } | |
39c626ae | 411 | |
c7e49c14 | 412 | write_unlock_irq(&tasklist_lock); |
39c626ae ON |
413 | BUG_ON(!list_empty(&tracer->ptraced)); |
414 | ||
415 | list_for_each_entry_safe(p, n, &ptrace_dead, ptrace_entry) { | |
416 | list_del_init(&p->ptrace_entry); | |
417 | release_task(p); | |
418 | } | |
c7e49c14 ON |
419 | |
420 | write_lock_irq(&tasklist_lock); | |
39c626ae ON |
421 | } |
422 | ||
1da177e4 LT |
423 | int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len) |
424 | { | |
425 | int copied = 0; | |
426 | ||
427 | while (len > 0) { | |
428 | char buf[128]; | |
429 | int this_len, retval; | |
430 | ||
431 | this_len = (len > sizeof(buf)) ? sizeof(buf) : len; | |
432 | retval = access_process_vm(tsk, src, buf, this_len, 0); | |
433 | if (!retval) { | |
434 | if (copied) | |
435 | break; | |
436 | return -EIO; | |
437 | } | |
438 | if (copy_to_user(dst, buf, retval)) | |
439 | return -EFAULT; | |
440 | copied += retval; | |
441 | src += retval; | |
442 | dst += retval; | |
3a709703 | 443 | len -= retval; |
1da177e4 LT |
444 | } |
445 | return copied; | |
446 | } | |
447 | ||
448 | int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len) | |
449 | { | |
450 | int copied = 0; | |
451 | ||
452 | while (len > 0) { | |
453 | char buf[128]; | |
454 | int this_len, retval; | |
455 | ||
456 | this_len = (len > sizeof(buf)) ? sizeof(buf) : len; | |
457 | if (copy_from_user(buf, src, this_len)) | |
458 | return -EFAULT; | |
459 | retval = access_process_vm(tsk, dst, buf, this_len, 1); | |
460 | if (!retval) { | |
461 | if (copied) | |
462 | break; | |
463 | return -EIO; | |
464 | } | |
465 | copied += retval; | |
466 | src += retval; | |
467 | dst += retval; | |
3a709703 | 468 | len -= retval; |
1da177e4 LT |
469 | } |
470 | return copied; | |
471 | } | |
472 | ||
4abf9869 | 473 | static int ptrace_setoptions(struct task_struct *child, unsigned long data) |
1da177e4 LT |
474 | { |
475 | child->ptrace &= ~PT_TRACE_MASK; | |
476 | ||
477 | if (data & PTRACE_O_TRACESYSGOOD) | |
478 | child->ptrace |= PT_TRACESYSGOOD; | |
479 | ||
480 | if (data & PTRACE_O_TRACEFORK) | |
481 | child->ptrace |= PT_TRACE_FORK; | |
482 | ||
483 | if (data & PTRACE_O_TRACEVFORK) | |
484 | child->ptrace |= PT_TRACE_VFORK; | |
485 | ||
486 | if (data & PTRACE_O_TRACECLONE) | |
487 | child->ptrace |= PT_TRACE_CLONE; | |
488 | ||
489 | if (data & PTRACE_O_TRACEEXEC) | |
490 | child->ptrace |= PT_TRACE_EXEC; | |
491 | ||
492 | if (data & PTRACE_O_TRACEVFORKDONE) | |
493 | child->ptrace |= PT_TRACE_VFORK_DONE; | |
494 | ||
495 | if (data & PTRACE_O_TRACEEXIT) | |
496 | child->ptrace |= PT_TRACE_EXIT; | |
497 | ||
498 | return (data & ~PTRACE_O_MASK) ? -EINVAL : 0; | |
499 | } | |
500 | ||
e16b2781 | 501 | static int ptrace_getsiginfo(struct task_struct *child, siginfo_t *info) |
1da177e4 | 502 | { |
e4961254 | 503 | unsigned long flags; |
1da177e4 LT |
504 | int error = -ESRCH; |
505 | ||
e4961254 | 506 | if (lock_task_sighand(child, &flags)) { |
1da177e4 | 507 | error = -EINVAL; |
1da177e4 | 508 | if (likely(child->last_siginfo != NULL)) { |
e16b2781 | 509 | *info = *child->last_siginfo; |
1da177e4 LT |
510 | error = 0; |
511 | } | |
e4961254 | 512 | unlock_task_sighand(child, &flags); |
1da177e4 | 513 | } |
1da177e4 LT |
514 | return error; |
515 | } | |
516 | ||
e16b2781 | 517 | static int ptrace_setsiginfo(struct task_struct *child, const siginfo_t *info) |
1da177e4 | 518 | { |
e4961254 | 519 | unsigned long flags; |
1da177e4 LT |
520 | int error = -ESRCH; |
521 | ||
e4961254 | 522 | if (lock_task_sighand(child, &flags)) { |
1da177e4 | 523 | error = -EINVAL; |
1da177e4 | 524 | if (likely(child->last_siginfo != NULL)) { |
e16b2781 | 525 | *child->last_siginfo = *info; |
1da177e4 LT |
526 | error = 0; |
527 | } | |
e4961254 | 528 | unlock_task_sighand(child, &flags); |
1da177e4 | 529 | } |
1da177e4 LT |
530 | return error; |
531 | } | |
532 | ||
36df29d7 RM |
533 | |
534 | #ifdef PTRACE_SINGLESTEP | |
535 | #define is_singlestep(request) ((request) == PTRACE_SINGLESTEP) | |
536 | #else | |
537 | #define is_singlestep(request) 0 | |
538 | #endif | |
539 | ||
5b88abbf RM |
540 | #ifdef PTRACE_SINGLEBLOCK |
541 | #define is_singleblock(request) ((request) == PTRACE_SINGLEBLOCK) | |
542 | #else | |
543 | #define is_singleblock(request) 0 | |
544 | #endif | |
545 | ||
36df29d7 RM |
546 | #ifdef PTRACE_SYSEMU |
547 | #define is_sysemu_singlestep(request) ((request) == PTRACE_SYSEMU_SINGLESTEP) | |
548 | #else | |
549 | #define is_sysemu_singlestep(request) 0 | |
550 | #endif | |
551 | ||
4abf9869 NK |
552 | static int ptrace_resume(struct task_struct *child, long request, |
553 | unsigned long data) | |
36df29d7 RM |
554 | { |
555 | if (!valid_signal(data)) | |
556 | return -EIO; | |
557 | ||
558 | if (request == PTRACE_SYSCALL) | |
559 | set_tsk_thread_flag(child, TIF_SYSCALL_TRACE); | |
560 | else | |
561 | clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); | |
562 | ||
563 | #ifdef TIF_SYSCALL_EMU | |
564 | if (request == PTRACE_SYSEMU || request == PTRACE_SYSEMU_SINGLESTEP) | |
565 | set_tsk_thread_flag(child, TIF_SYSCALL_EMU); | |
566 | else | |
567 | clear_tsk_thread_flag(child, TIF_SYSCALL_EMU); | |
568 | #endif | |
569 | ||
5b88abbf RM |
570 | if (is_singleblock(request)) { |
571 | if (unlikely(!arch_has_block_step())) | |
572 | return -EIO; | |
573 | user_enable_block_step(child); | |
574 | } else if (is_singlestep(request) || is_sysemu_singlestep(request)) { | |
36df29d7 RM |
575 | if (unlikely(!arch_has_single_step())) |
576 | return -EIO; | |
577 | user_enable_single_step(child); | |
3a709703 | 578 | } else { |
36df29d7 | 579 | user_disable_single_step(child); |
3a709703 | 580 | } |
36df29d7 RM |
581 | |
582 | child->exit_code = data; | |
0666fb51 | 583 | wake_up_state(child, __TASK_TRACED); |
36df29d7 RM |
584 | |
585 | return 0; | |
586 | } | |
587 | ||
2225a122 SS |
588 | #ifdef CONFIG_HAVE_ARCH_TRACEHOOK |
589 | ||
590 | static const struct user_regset * | |
591 | find_regset(const struct user_regset_view *view, unsigned int type) | |
592 | { | |
593 | const struct user_regset *regset; | |
594 | int n; | |
595 | ||
596 | for (n = 0; n < view->n; ++n) { | |
597 | regset = view->regsets + n; | |
598 | if (regset->core_note_type == type) | |
599 | return regset; | |
600 | } | |
601 | ||
602 | return NULL; | |
603 | } | |
604 | ||
605 | static int ptrace_regset(struct task_struct *task, int req, unsigned int type, | |
606 | struct iovec *kiov) | |
607 | { | |
608 | const struct user_regset_view *view = task_user_regset_view(task); | |
609 | const struct user_regset *regset = find_regset(view, type); | |
610 | int regset_no; | |
611 | ||
612 | if (!regset || (kiov->iov_len % regset->size) != 0) | |
c6a0dd7e | 613 | return -EINVAL; |
2225a122 SS |
614 | |
615 | regset_no = regset - view->regsets; | |
616 | kiov->iov_len = min(kiov->iov_len, | |
617 | (__kernel_size_t) (regset->n * regset->size)); | |
618 | ||
619 | if (req == PTRACE_GETREGSET) | |
620 | return copy_regset_to_user(task, view, regset_no, 0, | |
621 | kiov->iov_len, kiov->iov_base); | |
622 | else | |
623 | return copy_regset_from_user(task, view, regset_no, 0, | |
624 | kiov->iov_len, kiov->iov_base); | |
625 | } | |
626 | ||
627 | #endif | |
628 | ||
1da177e4 | 629 | int ptrace_request(struct task_struct *child, long request, |
4abf9869 | 630 | unsigned long addr, unsigned long data) |
1da177e4 LT |
631 | { |
632 | int ret = -EIO; | |
e16b2781 | 633 | siginfo_t siginfo; |
9fed81dc NK |
634 | void __user *datavp = (void __user *) data; |
635 | unsigned long __user *datalp = datavp; | |
1da177e4 LT |
636 | |
637 | switch (request) { | |
16c3e389 RM |
638 | case PTRACE_PEEKTEXT: |
639 | case PTRACE_PEEKDATA: | |
640 | return generic_ptrace_peekdata(child, addr, data); | |
641 | case PTRACE_POKETEXT: | |
642 | case PTRACE_POKEDATA: | |
643 | return generic_ptrace_pokedata(child, addr, data); | |
644 | ||
1da177e4 LT |
645 | #ifdef PTRACE_OLDSETOPTIONS |
646 | case PTRACE_OLDSETOPTIONS: | |
647 | #endif | |
648 | case PTRACE_SETOPTIONS: | |
649 | ret = ptrace_setoptions(child, data); | |
650 | break; | |
651 | case PTRACE_GETEVENTMSG: | |
9fed81dc | 652 | ret = put_user(child->ptrace_message, datalp); |
1da177e4 | 653 | break; |
e16b2781 | 654 | |
1da177e4 | 655 | case PTRACE_GETSIGINFO: |
e16b2781 RM |
656 | ret = ptrace_getsiginfo(child, &siginfo); |
657 | if (!ret) | |
9fed81dc | 658 | ret = copy_siginfo_to_user(datavp, &siginfo); |
1da177e4 | 659 | break; |
e16b2781 | 660 | |
1da177e4 | 661 | case PTRACE_SETSIGINFO: |
9fed81dc | 662 | if (copy_from_user(&siginfo, datavp, sizeof siginfo)) |
e16b2781 RM |
663 | ret = -EFAULT; |
664 | else | |
665 | ret = ptrace_setsiginfo(child, &siginfo); | |
1da177e4 | 666 | break; |
e16b2781 | 667 | |
1bcf5482 AD |
668 | case PTRACE_DETACH: /* detach a process that was attached. */ |
669 | ret = ptrace_detach(child, data); | |
670 | break; | |
36df29d7 | 671 | |
9c1a1259 MF |
672 | #ifdef CONFIG_BINFMT_ELF_FDPIC |
673 | case PTRACE_GETFDPIC: { | |
e0129ef9 | 674 | struct mm_struct *mm = get_task_mm(child); |
9c1a1259 MF |
675 | unsigned long tmp = 0; |
676 | ||
e0129ef9 ON |
677 | ret = -ESRCH; |
678 | if (!mm) | |
679 | break; | |
680 | ||
9c1a1259 MF |
681 | switch (addr) { |
682 | case PTRACE_GETFDPIC_EXEC: | |
e0129ef9 | 683 | tmp = mm->context.exec_fdpic_loadmap; |
9c1a1259 MF |
684 | break; |
685 | case PTRACE_GETFDPIC_INTERP: | |
e0129ef9 | 686 | tmp = mm->context.interp_fdpic_loadmap; |
9c1a1259 MF |
687 | break; |
688 | default: | |
689 | break; | |
690 | } | |
e0129ef9 | 691 | mmput(mm); |
9c1a1259 | 692 | |
9fed81dc | 693 | ret = put_user(tmp, datalp); |
9c1a1259 MF |
694 | break; |
695 | } | |
696 | #endif | |
697 | ||
36df29d7 RM |
698 | #ifdef PTRACE_SINGLESTEP |
699 | case PTRACE_SINGLESTEP: | |
700 | #endif | |
5b88abbf RM |
701 | #ifdef PTRACE_SINGLEBLOCK |
702 | case PTRACE_SINGLEBLOCK: | |
703 | #endif | |
36df29d7 RM |
704 | #ifdef PTRACE_SYSEMU |
705 | case PTRACE_SYSEMU: | |
706 | case PTRACE_SYSEMU_SINGLESTEP: | |
707 | #endif | |
708 | case PTRACE_SYSCALL: | |
709 | case PTRACE_CONT: | |
710 | return ptrace_resume(child, request, data); | |
711 | ||
712 | case PTRACE_KILL: | |
713 | if (child->exit_state) /* already dead */ | |
714 | return 0; | |
715 | return ptrace_resume(child, request, SIGKILL); | |
716 | ||
2225a122 SS |
717 | #ifdef CONFIG_HAVE_ARCH_TRACEHOOK |
718 | case PTRACE_GETREGSET: | |
719 | case PTRACE_SETREGSET: | |
720 | { | |
721 | struct iovec kiov; | |
9fed81dc | 722 | struct iovec __user *uiov = datavp; |
2225a122 SS |
723 | |
724 | if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov))) | |
725 | return -EFAULT; | |
726 | ||
727 | if (__get_user(kiov.iov_base, &uiov->iov_base) || | |
728 | __get_user(kiov.iov_len, &uiov->iov_len)) | |
729 | return -EFAULT; | |
730 | ||
731 | ret = ptrace_regset(child, request, addr, &kiov); | |
732 | if (!ret) | |
733 | ret = __put_user(kiov.iov_len, &uiov->iov_len); | |
734 | break; | |
735 | } | |
736 | #endif | |
1da177e4 LT |
737 | default: |
738 | break; | |
739 | } | |
740 | ||
741 | return ret; | |
742 | } | |
481bed45 | 743 | |
8053bdd5 | 744 | static struct task_struct *ptrace_get_task_struct(pid_t pid) |
6b9c7ed8 CH |
745 | { |
746 | struct task_struct *child; | |
481bed45 | 747 | |
8053bdd5 | 748 | rcu_read_lock(); |
228ebcbe | 749 | child = find_task_by_vpid(pid); |
481bed45 CH |
750 | if (child) |
751 | get_task_struct(child); | |
8053bdd5 | 752 | rcu_read_unlock(); |
f400e198 | 753 | |
481bed45 | 754 | if (!child) |
6b9c7ed8 CH |
755 | return ERR_PTR(-ESRCH); |
756 | return child; | |
481bed45 CH |
757 | } |
758 | ||
0ac15559 CH |
759 | #ifndef arch_ptrace_attach |
760 | #define arch_ptrace_attach(child) do { } while (0) | |
761 | #endif | |
762 | ||
4abf9869 NK |
763 | SYSCALL_DEFINE4(ptrace, long, request, long, pid, unsigned long, addr, |
764 | unsigned long, data) | |
481bed45 CH |
765 | { |
766 | struct task_struct *child; | |
767 | long ret; | |
768 | ||
6b9c7ed8 CH |
769 | if (request == PTRACE_TRACEME) { |
770 | ret = ptrace_traceme(); | |
6ea6dd93 HS |
771 | if (!ret) |
772 | arch_ptrace_attach(current); | |
481bed45 | 773 | goto out; |
6b9c7ed8 CH |
774 | } |
775 | ||
776 | child = ptrace_get_task_struct(pid); | |
777 | if (IS_ERR(child)) { | |
778 | ret = PTR_ERR(child); | |
779 | goto out; | |
780 | } | |
481bed45 CH |
781 | |
782 | if (request == PTRACE_ATTACH) { | |
783 | ret = ptrace_attach(child); | |
0ac15559 CH |
784 | /* |
785 | * Some architectures need to do book-keeping after | |
786 | * a ptrace attach. | |
787 | */ | |
788 | if (!ret) | |
789 | arch_ptrace_attach(child); | |
005f18df | 790 | goto out_put_task_struct; |
481bed45 CH |
791 | } |
792 | ||
793 | ret = ptrace_check_attach(child, request == PTRACE_KILL); | |
794 | if (ret < 0) | |
795 | goto out_put_task_struct; | |
796 | ||
797 | ret = arch_ptrace(child, request, addr, data); | |
481bed45 CH |
798 | |
799 | out_put_task_struct: | |
800 | put_task_struct(child); | |
801 | out: | |
481bed45 CH |
802 | return ret; |
803 | } | |
76647323 | 804 | |
4abf9869 NK |
805 | int generic_ptrace_peekdata(struct task_struct *tsk, unsigned long addr, |
806 | unsigned long data) | |
76647323 AD |
807 | { |
808 | unsigned long tmp; | |
809 | int copied; | |
810 | ||
811 | copied = access_process_vm(tsk, addr, &tmp, sizeof(tmp), 0); | |
812 | if (copied != sizeof(tmp)) | |
813 | return -EIO; | |
814 | return put_user(tmp, (unsigned long __user *)data); | |
815 | } | |
f284ce72 | 816 | |
4abf9869 NK |
817 | int generic_ptrace_pokedata(struct task_struct *tsk, unsigned long addr, |
818 | unsigned long data) | |
f284ce72 AD |
819 | { |
820 | int copied; | |
821 | ||
822 | copied = access_process_vm(tsk, addr, &data, sizeof(data), 1); | |
823 | return (copied == sizeof(data)) ? 0 : -EIO; | |
824 | } | |
032d82d9 | 825 | |
96b8936a | 826 | #if defined CONFIG_COMPAT |
032d82d9 RM |
827 | #include <linux/compat.h> |
828 | ||
829 | int compat_ptrace_request(struct task_struct *child, compat_long_t request, | |
830 | compat_ulong_t addr, compat_ulong_t data) | |
831 | { | |
832 | compat_ulong_t __user *datap = compat_ptr(data); | |
833 | compat_ulong_t word; | |
e16b2781 | 834 | siginfo_t siginfo; |
032d82d9 RM |
835 | int ret; |
836 | ||
837 | switch (request) { | |
838 | case PTRACE_PEEKTEXT: | |
839 | case PTRACE_PEEKDATA: | |
840 | ret = access_process_vm(child, addr, &word, sizeof(word), 0); | |
841 | if (ret != sizeof(word)) | |
842 | ret = -EIO; | |
843 | else | |
844 | ret = put_user(word, datap); | |
845 | break; | |
846 | ||
847 | case PTRACE_POKETEXT: | |
848 | case PTRACE_POKEDATA: | |
849 | ret = access_process_vm(child, addr, &data, sizeof(data), 1); | |
850 | ret = (ret != sizeof(data) ? -EIO : 0); | |
851 | break; | |
852 | ||
853 | case PTRACE_GETEVENTMSG: | |
854 | ret = put_user((compat_ulong_t) child->ptrace_message, datap); | |
855 | break; | |
856 | ||
e16b2781 RM |
857 | case PTRACE_GETSIGINFO: |
858 | ret = ptrace_getsiginfo(child, &siginfo); | |
859 | if (!ret) | |
860 | ret = copy_siginfo_to_user32( | |
861 | (struct compat_siginfo __user *) datap, | |
862 | &siginfo); | |
863 | break; | |
864 | ||
865 | case PTRACE_SETSIGINFO: | |
866 | memset(&siginfo, 0, sizeof siginfo); | |
867 | if (copy_siginfo_from_user32( | |
868 | &siginfo, (struct compat_siginfo __user *) datap)) | |
869 | ret = -EFAULT; | |
870 | else | |
871 | ret = ptrace_setsiginfo(child, &siginfo); | |
872 | break; | |
2225a122 SS |
873 | #ifdef CONFIG_HAVE_ARCH_TRACEHOOK |
874 | case PTRACE_GETREGSET: | |
875 | case PTRACE_SETREGSET: | |
876 | { | |
877 | struct iovec kiov; | |
878 | struct compat_iovec __user *uiov = | |
879 | (struct compat_iovec __user *) datap; | |
880 | compat_uptr_t ptr; | |
881 | compat_size_t len; | |
882 | ||
883 | if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov))) | |
884 | return -EFAULT; | |
885 | ||
886 | if (__get_user(ptr, &uiov->iov_base) || | |
887 | __get_user(len, &uiov->iov_len)) | |
888 | return -EFAULT; | |
889 | ||
890 | kiov.iov_base = compat_ptr(ptr); | |
891 | kiov.iov_len = len; | |
892 | ||
893 | ret = ptrace_regset(child, request, addr, &kiov); | |
894 | if (!ret) | |
895 | ret = __put_user(kiov.iov_len, &uiov->iov_len); | |
896 | break; | |
897 | } | |
898 | #endif | |
e16b2781 | 899 | |
032d82d9 RM |
900 | default: |
901 | ret = ptrace_request(child, request, addr, data); | |
902 | } | |
903 | ||
904 | return ret; | |
905 | } | |
c269f196 | 906 | |
c269f196 RM |
907 | asmlinkage long compat_sys_ptrace(compat_long_t request, compat_long_t pid, |
908 | compat_long_t addr, compat_long_t data) | |
909 | { | |
910 | struct task_struct *child; | |
911 | long ret; | |
912 | ||
c269f196 RM |
913 | if (request == PTRACE_TRACEME) { |
914 | ret = ptrace_traceme(); | |
915 | goto out; | |
916 | } | |
917 | ||
918 | child = ptrace_get_task_struct(pid); | |
919 | if (IS_ERR(child)) { | |
920 | ret = PTR_ERR(child); | |
921 | goto out; | |
922 | } | |
923 | ||
924 | if (request == PTRACE_ATTACH) { | |
925 | ret = ptrace_attach(child); | |
926 | /* | |
927 | * Some architectures need to do book-keeping after | |
928 | * a ptrace attach. | |
929 | */ | |
930 | if (!ret) | |
931 | arch_ptrace_attach(child); | |
932 | goto out_put_task_struct; | |
933 | } | |
934 | ||
935 | ret = ptrace_check_attach(child, request == PTRACE_KILL); | |
936 | if (!ret) | |
937 | ret = compat_arch_ptrace(child, request, addr, data); | |
938 | ||
939 | out_put_task_struct: | |
940 | put_task_struct(child); | |
941 | out: | |
c269f196 RM |
942 | return ret; |
943 | } | |
96b8936a | 944 | #endif /* CONFIG_COMPAT */ |
bf26c018 FW |
945 | |
946 | #ifdef CONFIG_HAVE_HW_BREAKPOINT | |
947 | int ptrace_get_breakpoints(struct task_struct *tsk) | |
948 | { | |
949 | if (atomic_inc_not_zero(&tsk->ptrace_bp_refcnt)) | |
950 | return 0; | |
951 | ||
952 | return -1; | |
953 | } | |
954 | ||
955 | void ptrace_put_breakpoints(struct task_struct *tsk) | |
956 | { | |
957 | if (atomic_dec_and_test(&tsk->ptrace_bp_refcnt)) | |
958 | flush_ptrace_hw_breakpoint(tsk); | |
959 | } | |
960 | #endif /* CONFIG_HAVE_HW_BREAKPOINT */ |