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