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 | 84 | |
73ddff2b TH |
85 | /* |
86 | * Clear all pending traps and TRAPPING. TRAPPING should be | |
87 | * cleared regardless of JOBCTL_STOP_PENDING. Do it explicitly. | |
88 | */ | |
89 | task_clear_jobctl_pending(child, JOBCTL_TRAP_MASK); | |
90 | task_clear_jobctl_trapping(child); | |
91 | ||
0e9f0a4a | 92 | /* |
a8f072c1 | 93 | * Reinstate JOBCTL_STOP_PENDING if group stop is in effect and |
0e9f0a4a TH |
94 | * @child isn't dead. |
95 | */ | |
96 | if (!(child->flags & PF_EXITING) && | |
97 | (child->signal->flags & SIGNAL_STOP_STOPPED || | |
98 | child->signal->group_stop_count)) | |
a8f072c1 | 99 | child->jobctl |= JOBCTL_STOP_PENDING; |
0e9f0a4a TH |
100 | |
101 | /* | |
102 | * If transition to TASK_STOPPED is pending or in TASK_TRACED, kick | |
103 | * @child in the butt. Note that @resume should be used iff @child | |
104 | * is in TASK_TRACED; otherwise, we might unduly disrupt | |
105 | * TASK_KILLABLE sleeps. | |
106 | */ | |
a8f072c1 | 107 | if (child->jobctl & JOBCTL_STOP_PENDING || task_is_traced(child)) |
0e9f0a4a TH |
108 | signal_wake_up(child, task_is_traced(child)); |
109 | ||
1da177e4 | 110 | spin_unlock(&child->sighand->siglock); |
1da177e4 LT |
111 | } |
112 | ||
755e276b TH |
113 | /** |
114 | * ptrace_check_attach - check whether ptracee is ready for ptrace operation | |
115 | * @child: ptracee to check for | |
116 | * @ignore_state: don't check whether @child is currently %TASK_TRACED | |
117 | * | |
118 | * Check whether @child is being ptraced by %current and ready for further | |
119 | * ptrace operations. If @ignore_state is %false, @child also should be in | |
120 | * %TASK_TRACED state and on return the child is guaranteed to be traced | |
121 | * and not executing. If @ignore_state is %true, @child can be in any | |
122 | * state. | |
123 | * | |
124 | * CONTEXT: | |
125 | * Grabs and releases tasklist_lock and @child->sighand->siglock. | |
126 | * | |
127 | * RETURNS: | |
128 | * 0 on success, -ESRCH if %child is not ready. | |
1da177e4 | 129 | */ |
755e276b | 130 | int ptrace_check_attach(struct task_struct *child, bool ignore_state) |
1da177e4 LT |
131 | { |
132 | int ret = -ESRCH; | |
133 | ||
134 | /* | |
135 | * We take the read lock around doing both checks to close a | |
136 | * possible race where someone else was tracing our child and | |
137 | * detached between these two checks. After this locked check, | |
138 | * we are sure that this is our traced child and that can only | |
139 | * be changed by us so it's not changing right after this. | |
140 | */ | |
141 | read_lock(&tasklist_lock); | |
c0c0b649 | 142 | if ((child->ptrace & PT_PTRACED) && child->parent == current) { |
c0c0b649 ON |
143 | /* |
144 | * child->sighand can't be NULL, release_task() | |
145 | * does ptrace_unlink() before __exit_signal(). | |
146 | */ | |
1da177e4 | 147 | spin_lock_irq(&child->sighand->siglock); |
321fb561 | 148 | WARN_ON_ONCE(task_is_stopped(child)); |
755e276b | 149 | if (task_is_traced(child) || ignore_state) |
321fb561 | 150 | ret = 0; |
1da177e4 LT |
151 | spin_unlock_irq(&child->sighand->siglock); |
152 | } | |
153 | read_unlock(&tasklist_lock); | |
154 | ||
755e276b | 155 | if (!ret && !ignore_state) |
85ba2d86 | 156 | ret = wait_task_inactive(child, TASK_TRACED) ? 0 : -ESRCH; |
1da177e4 LT |
157 | |
158 | /* All systems go.. */ | |
159 | return ret; | |
160 | } | |
161 | ||
006ebb40 | 162 | int __ptrace_may_access(struct task_struct *task, unsigned int mode) |
ab8d11be | 163 | { |
c69e8d9c | 164 | const struct cred *cred = current_cred(), *tcred; |
b6dff3ec | 165 | |
df26c40e EB |
166 | /* May we inspect the given task? |
167 | * This check is used both for attaching with ptrace | |
168 | * and for allowing access to sensitive information in /proc. | |
169 | * | |
170 | * ptrace_attach denies several cases that /proc allows | |
171 | * because setting up the necessary parent/child relationship | |
172 | * or halting the specified task is impossible. | |
173 | */ | |
174 | int dumpable = 0; | |
175 | /* Don't let security modules deny introspection */ | |
176 | if (task == current) | |
177 | return 0; | |
c69e8d9c DH |
178 | rcu_read_lock(); |
179 | tcred = __task_cred(task); | |
8409cca7 SH |
180 | if (cred->user->user_ns == tcred->user->user_ns && |
181 | (cred->uid == tcred->euid && | |
182 | cred->uid == tcred->suid && | |
183 | cred->uid == tcred->uid && | |
184 | cred->gid == tcred->egid && | |
185 | cred->gid == tcred->sgid && | |
186 | cred->gid == tcred->gid)) | |
187 | goto ok; | |
188 | if (ns_capable(tcred->user->user_ns, CAP_SYS_PTRACE)) | |
189 | goto ok; | |
190 | rcu_read_unlock(); | |
191 | return -EPERM; | |
192 | ok: | |
c69e8d9c | 193 | rcu_read_unlock(); |
ab8d11be | 194 | smp_rmb(); |
df26c40e | 195 | if (task->mm) |
6c5d5238 | 196 | dumpable = get_dumpable(task->mm); |
8409cca7 | 197 | if (!dumpable && !task_ns_capable(task, CAP_SYS_PTRACE)) |
ab8d11be MS |
198 | return -EPERM; |
199 | ||
9e48858f | 200 | return security_ptrace_access_check(task, mode); |
ab8d11be MS |
201 | } |
202 | ||
006ebb40 | 203 | bool ptrace_may_access(struct task_struct *task, unsigned int mode) |
ab8d11be MS |
204 | { |
205 | int err; | |
206 | task_lock(task); | |
006ebb40 | 207 | err = __ptrace_may_access(task, mode); |
ab8d11be | 208 | task_unlock(task); |
3a709703 | 209 | return !err; |
ab8d11be MS |
210 | } |
211 | ||
3544d72a TH |
212 | static int ptrace_attach(struct task_struct *task, long request, |
213 | unsigned long flags) | |
1da177e4 | 214 | { |
3544d72a | 215 | bool seize = (request == PTRACE_SEIZE); |
1da177e4 | 216 | int retval; |
f5b40e36 | 217 | |
3544d72a TH |
218 | /* |
219 | * SEIZE will enable new ptrace behaviors which will be implemented | |
220 | * gradually. SEIZE_DEVEL is used to prevent applications | |
221 | * expecting full SEIZE behaviors trapping on kernel commits which | |
222 | * are still in the process of implementing them. | |
223 | * | |
224 | * Only test programs for new ptrace behaviors being implemented | |
225 | * should set SEIZE_DEVEL. If unset, SEIZE will fail with -EIO. | |
226 | * | |
227 | * Once SEIZE behaviors are completely implemented, this flag and | |
228 | * the following test will be removed. | |
229 | */ | |
230 | retval = -EIO; | |
231 | if (seize && !(flags & PTRACE_SEIZE_DEVEL)) | |
232 | goto out; | |
233 | ||
a5cb013d AV |
234 | audit_ptrace(task); |
235 | ||
1da177e4 | 236 | retval = -EPERM; |
b79b7ba9 ON |
237 | if (unlikely(task->flags & PF_KTHREAD)) |
238 | goto out; | |
bac0abd6 | 239 | if (same_thread_group(task, current)) |
f5b40e36 LT |
240 | goto out; |
241 | ||
f2f0b00a ON |
242 | /* |
243 | * Protect exec's credential calculations against our interference; | |
5e751e99 DH |
244 | * interference; SUID, SGID and LSM creds get determined differently |
245 | * under ptrace. | |
d84f4f99 | 246 | */ |
793285fc | 247 | retval = -ERESTARTNOINTR; |
9b1bf12d | 248 | if (mutex_lock_interruptible(&task->signal->cred_guard_mutex)) |
d84f4f99 | 249 | goto out; |
f5b40e36 | 250 | |
4b105cbb | 251 | task_lock(task); |
006ebb40 | 252 | retval = __ptrace_may_access(task, PTRACE_MODE_ATTACH); |
4b105cbb | 253 | task_unlock(task); |
1da177e4 | 254 | if (retval) |
4b105cbb | 255 | goto unlock_creds; |
1da177e4 | 256 | |
4b105cbb | 257 | write_lock_irq(&tasklist_lock); |
b79b7ba9 ON |
258 | retval = -EPERM; |
259 | if (unlikely(task->exit_state)) | |
4b105cbb | 260 | goto unlock_tasklist; |
f2f0b00a | 261 | if (task->ptrace) |
4b105cbb | 262 | goto unlock_tasklist; |
b79b7ba9 | 263 | |
f2f0b00a | 264 | task->ptrace = PT_PTRACED; |
3544d72a TH |
265 | if (seize) |
266 | task->ptrace |= PT_SEIZED; | |
8409cca7 | 267 | if (task_ns_capable(task, CAP_SYS_PTRACE)) |
1da177e4 | 268 | task->ptrace |= PT_PTRACE_CAP; |
1da177e4 | 269 | |
1da177e4 | 270 | __ptrace_link(task, current); |
3544d72a TH |
271 | |
272 | /* SEIZE doesn't trap tracee on attach */ | |
273 | if (!seize) | |
274 | send_sig_info(SIGSTOP, SEND_SIG_FORCED, task); | |
b79b7ba9 | 275 | |
d79fdd6d TH |
276 | spin_lock(&task->sighand->siglock); |
277 | ||
278 | /* | |
73ddff2b | 279 | * If the task is already STOPPED, set JOBCTL_TRAP_STOP and |
d79fdd6d TH |
280 | * TRAPPING, and kick it so that it transits to TRACED. TRAPPING |
281 | * will be cleared if the child completes the transition or any | |
282 | * event which clears the group stop states happens. We'll wait | |
283 | * for the transition to complete before returning from this | |
284 | * function. | |
285 | * | |
286 | * This hides STOPPED -> RUNNING -> TRACED transition from the | |
287 | * attaching thread but a different thread in the same group can | |
288 | * still observe the transient RUNNING state. IOW, if another | |
289 | * thread's WNOHANG wait(2) on the stopped tracee races against | |
290 | * ATTACH, the wait(2) may fail due to the transient RUNNING. | |
291 | * | |
292 | * The following task_is_stopped() test is safe as both transitions | |
293 | * in and out of STOPPED are protected by siglock. | |
294 | */ | |
7dd3db54 | 295 | if (task_is_stopped(task) && |
73ddff2b | 296 | task_set_jobctl_pending(task, JOBCTL_TRAP_STOP | JOBCTL_TRAPPING)) |
d79fdd6d | 297 | signal_wake_up(task, 1); |
d79fdd6d TH |
298 | |
299 | spin_unlock(&task->sighand->siglock); | |
300 | ||
b79b7ba9 | 301 | retval = 0; |
4b105cbb ON |
302 | unlock_tasklist: |
303 | write_unlock_irq(&tasklist_lock); | |
304 | unlock_creds: | |
9b1bf12d | 305 | mutex_unlock(&task->signal->cred_guard_mutex); |
f5b40e36 | 306 | out: |
0b1007c3 | 307 | if (!retval) |
62c124ff TH |
308 | wait_on_bit(&task->jobctl, JOBCTL_TRAPPING_BIT, |
309 | ptrace_trapping_sleep_fn, TASK_UNINTERRUPTIBLE); | |
1da177e4 LT |
310 | return retval; |
311 | } | |
312 | ||
f2f0b00a ON |
313 | /** |
314 | * ptrace_traceme -- helper for PTRACE_TRACEME | |
315 | * | |
316 | * Performs checks and sets PT_PTRACED. | |
317 | * Should be used by all ptrace implementations for PTRACE_TRACEME. | |
318 | */ | |
e3e89cc5 | 319 | static int ptrace_traceme(void) |
f2f0b00a ON |
320 | { |
321 | int ret = -EPERM; | |
322 | ||
4b105cbb ON |
323 | write_lock_irq(&tasklist_lock); |
324 | /* Are we already being traced? */ | |
f2f0b00a | 325 | if (!current->ptrace) { |
f2f0b00a | 326 | ret = security_ptrace_traceme(current->parent); |
f2f0b00a ON |
327 | /* |
328 | * Check PF_EXITING to ensure ->real_parent has not passed | |
329 | * exit_ptrace(). Otherwise we don't report the error but | |
330 | * pretend ->real_parent untraces us right after return. | |
331 | */ | |
332 | if (!ret && !(current->real_parent->flags & PF_EXITING)) { | |
333 | current->ptrace = PT_PTRACED; | |
334 | __ptrace_link(current, current->real_parent); | |
335 | } | |
f2f0b00a | 336 | } |
4b105cbb ON |
337 | write_unlock_irq(&tasklist_lock); |
338 | ||
f2f0b00a ON |
339 | return ret; |
340 | } | |
341 | ||
39c626ae ON |
342 | /* |
343 | * Called with irqs disabled, returns true if childs should reap themselves. | |
344 | */ | |
345 | static int ignoring_children(struct sighand_struct *sigh) | |
346 | { | |
347 | int ret; | |
348 | spin_lock(&sigh->siglock); | |
349 | ret = (sigh->action[SIGCHLD-1].sa.sa_handler == SIG_IGN) || | |
350 | (sigh->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT); | |
351 | spin_unlock(&sigh->siglock); | |
352 | return ret; | |
353 | } | |
354 | ||
355 | /* | |
356 | * Called with tasklist_lock held for writing. | |
357 | * Unlink a traced task, and clean it up if it was a traced zombie. | |
358 | * Return true if it needs to be reaped with release_task(). | |
359 | * (We can't call release_task() here because we already hold tasklist_lock.) | |
360 | * | |
361 | * If it's a zombie, our attachedness prevented normal parent notification | |
362 | * or self-reaping. Do notification now if it would have happened earlier. | |
363 | * If it should reap itself, return true. | |
364 | * | |
a7f0765e ON |
365 | * If it's our own child, there is no notification to do. But if our normal |
366 | * children self-reap, then this child was prevented by ptrace and we must | |
367 | * reap it now, in that case we must also wake up sub-threads sleeping in | |
368 | * do_wait(). | |
39c626ae ON |
369 | */ |
370 | static bool __ptrace_detach(struct task_struct *tracer, struct task_struct *p) | |
371 | { | |
372 | __ptrace_unlink(p); | |
373 | ||
374 | if (p->exit_state == EXIT_ZOMBIE) { | |
375 | if (!task_detached(p) && thread_group_empty(p)) { | |
376 | if (!same_thread_group(p->real_parent, tracer)) | |
377 | do_notify_parent(p, p->exit_signal); | |
a7f0765e ON |
378 | else if (ignoring_children(tracer->sighand)) { |
379 | __wake_up_parent(p, tracer); | |
39c626ae | 380 | p->exit_signal = -1; |
a7f0765e | 381 | } |
39c626ae ON |
382 | } |
383 | if (task_detached(p)) { | |
384 | /* Mark it as in the process of being reaped. */ | |
385 | p->exit_state = EXIT_DEAD; | |
386 | return true; | |
387 | } | |
388 | } | |
389 | ||
390 | return false; | |
391 | } | |
392 | ||
e3e89cc5 | 393 | static int ptrace_detach(struct task_struct *child, unsigned int data) |
1da177e4 | 394 | { |
39c626ae | 395 | bool dead = false; |
4576145c | 396 | |
7ed20e1a | 397 | if (!valid_signal(data)) |
5ecfbae0 | 398 | return -EIO; |
1da177e4 LT |
399 | |
400 | /* Architecture-specific hardware disable .. */ | |
401 | ptrace_disable(child); | |
7d941432 | 402 | clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); |
1da177e4 | 403 | |
95c3eb76 | 404 | write_lock_irq(&tasklist_lock); |
39c626ae ON |
405 | /* |
406 | * This child can be already killed. Make sure de_thread() or | |
407 | * our sub-thread doing do_wait() didn't do release_task() yet. | |
408 | */ | |
95c3eb76 ON |
409 | if (child->ptrace) { |
410 | child->exit_code = data; | |
4576145c | 411 | dead = __ptrace_detach(current, child); |
95c3eb76 | 412 | } |
1da177e4 LT |
413 | write_unlock_irq(&tasklist_lock); |
414 | ||
4576145c ON |
415 | if (unlikely(dead)) |
416 | release_task(child); | |
417 | ||
1da177e4 LT |
418 | return 0; |
419 | } | |
420 | ||
39c626ae | 421 | /* |
c7e49c14 ON |
422 | * Detach all tasks we were using ptrace on. Called with tasklist held |
423 | * for writing, and returns with it held too. But note it can release | |
424 | * and reacquire the lock. | |
39c626ae ON |
425 | */ |
426 | void exit_ptrace(struct task_struct *tracer) | |
c4b5ed25 NK |
427 | __releases(&tasklist_lock) |
428 | __acquires(&tasklist_lock) | |
39c626ae ON |
429 | { |
430 | struct task_struct *p, *n; | |
431 | LIST_HEAD(ptrace_dead); | |
432 | ||
c7e49c14 ON |
433 | if (likely(list_empty(&tracer->ptraced))) |
434 | return; | |
435 | ||
39c626ae ON |
436 | list_for_each_entry_safe(p, n, &tracer->ptraced, ptrace_entry) { |
437 | if (__ptrace_detach(tracer, p)) | |
438 | list_add(&p->ptrace_entry, &ptrace_dead); | |
439 | } | |
39c626ae | 440 | |
c7e49c14 | 441 | write_unlock_irq(&tasklist_lock); |
39c626ae ON |
442 | BUG_ON(!list_empty(&tracer->ptraced)); |
443 | ||
444 | list_for_each_entry_safe(p, n, &ptrace_dead, ptrace_entry) { | |
445 | list_del_init(&p->ptrace_entry); | |
446 | release_task(p); | |
447 | } | |
c7e49c14 ON |
448 | |
449 | write_lock_irq(&tasklist_lock); | |
39c626ae ON |
450 | } |
451 | ||
1da177e4 LT |
452 | int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len) |
453 | { | |
454 | int copied = 0; | |
455 | ||
456 | while (len > 0) { | |
457 | char buf[128]; | |
458 | int this_len, retval; | |
459 | ||
460 | this_len = (len > sizeof(buf)) ? sizeof(buf) : len; | |
461 | retval = access_process_vm(tsk, src, buf, this_len, 0); | |
462 | if (!retval) { | |
463 | if (copied) | |
464 | break; | |
465 | return -EIO; | |
466 | } | |
467 | if (copy_to_user(dst, buf, retval)) | |
468 | return -EFAULT; | |
469 | copied += retval; | |
470 | src += retval; | |
471 | dst += retval; | |
3a709703 | 472 | len -= retval; |
1da177e4 LT |
473 | } |
474 | return copied; | |
475 | } | |
476 | ||
477 | int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len) | |
478 | { | |
479 | int copied = 0; | |
480 | ||
481 | while (len > 0) { | |
482 | char buf[128]; | |
483 | int this_len, retval; | |
484 | ||
485 | this_len = (len > sizeof(buf)) ? sizeof(buf) : len; | |
486 | if (copy_from_user(buf, src, this_len)) | |
487 | return -EFAULT; | |
488 | retval = access_process_vm(tsk, dst, buf, this_len, 1); | |
489 | if (!retval) { | |
490 | if (copied) | |
491 | break; | |
492 | return -EIO; | |
493 | } | |
494 | copied += retval; | |
495 | src += retval; | |
496 | dst += retval; | |
3a709703 | 497 | len -= retval; |
1da177e4 LT |
498 | } |
499 | return copied; | |
500 | } | |
501 | ||
4abf9869 | 502 | static int ptrace_setoptions(struct task_struct *child, unsigned long data) |
1da177e4 LT |
503 | { |
504 | child->ptrace &= ~PT_TRACE_MASK; | |
505 | ||
506 | if (data & PTRACE_O_TRACESYSGOOD) | |
507 | child->ptrace |= PT_TRACESYSGOOD; | |
508 | ||
509 | if (data & PTRACE_O_TRACEFORK) | |
510 | child->ptrace |= PT_TRACE_FORK; | |
511 | ||
512 | if (data & PTRACE_O_TRACEVFORK) | |
513 | child->ptrace |= PT_TRACE_VFORK; | |
514 | ||
515 | if (data & PTRACE_O_TRACECLONE) | |
516 | child->ptrace |= PT_TRACE_CLONE; | |
517 | ||
518 | if (data & PTRACE_O_TRACEEXEC) | |
519 | child->ptrace |= PT_TRACE_EXEC; | |
520 | ||
521 | if (data & PTRACE_O_TRACEVFORKDONE) | |
522 | child->ptrace |= PT_TRACE_VFORK_DONE; | |
523 | ||
524 | if (data & PTRACE_O_TRACEEXIT) | |
525 | child->ptrace |= PT_TRACE_EXIT; | |
526 | ||
527 | return (data & ~PTRACE_O_MASK) ? -EINVAL : 0; | |
528 | } | |
529 | ||
e16b2781 | 530 | static int ptrace_getsiginfo(struct task_struct *child, siginfo_t *info) |
1da177e4 | 531 | { |
e4961254 | 532 | unsigned long flags; |
1da177e4 LT |
533 | int error = -ESRCH; |
534 | ||
e4961254 | 535 | if (lock_task_sighand(child, &flags)) { |
1da177e4 | 536 | error = -EINVAL; |
1da177e4 | 537 | if (likely(child->last_siginfo != NULL)) { |
e16b2781 | 538 | *info = *child->last_siginfo; |
1da177e4 LT |
539 | error = 0; |
540 | } | |
e4961254 | 541 | unlock_task_sighand(child, &flags); |
1da177e4 | 542 | } |
1da177e4 LT |
543 | return error; |
544 | } | |
545 | ||
e16b2781 | 546 | static int ptrace_setsiginfo(struct task_struct *child, const siginfo_t *info) |
1da177e4 | 547 | { |
e4961254 | 548 | unsigned long flags; |
1da177e4 LT |
549 | int error = -ESRCH; |
550 | ||
e4961254 | 551 | if (lock_task_sighand(child, &flags)) { |
1da177e4 | 552 | error = -EINVAL; |
1da177e4 | 553 | if (likely(child->last_siginfo != NULL)) { |
e16b2781 | 554 | *child->last_siginfo = *info; |
1da177e4 LT |
555 | error = 0; |
556 | } | |
e4961254 | 557 | unlock_task_sighand(child, &flags); |
1da177e4 | 558 | } |
1da177e4 LT |
559 | return error; |
560 | } | |
561 | ||
36df29d7 RM |
562 | |
563 | #ifdef PTRACE_SINGLESTEP | |
564 | #define is_singlestep(request) ((request) == PTRACE_SINGLESTEP) | |
565 | #else | |
566 | #define is_singlestep(request) 0 | |
567 | #endif | |
568 | ||
5b88abbf RM |
569 | #ifdef PTRACE_SINGLEBLOCK |
570 | #define is_singleblock(request) ((request) == PTRACE_SINGLEBLOCK) | |
571 | #else | |
572 | #define is_singleblock(request) 0 | |
573 | #endif | |
574 | ||
36df29d7 RM |
575 | #ifdef PTRACE_SYSEMU |
576 | #define is_sysemu_singlestep(request) ((request) == PTRACE_SYSEMU_SINGLESTEP) | |
577 | #else | |
578 | #define is_sysemu_singlestep(request) 0 | |
579 | #endif | |
580 | ||
4abf9869 NK |
581 | static int ptrace_resume(struct task_struct *child, long request, |
582 | unsigned long data) | |
36df29d7 RM |
583 | { |
584 | if (!valid_signal(data)) | |
585 | return -EIO; | |
586 | ||
587 | if (request == PTRACE_SYSCALL) | |
588 | set_tsk_thread_flag(child, TIF_SYSCALL_TRACE); | |
589 | else | |
590 | clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); | |
591 | ||
592 | #ifdef TIF_SYSCALL_EMU | |
593 | if (request == PTRACE_SYSEMU || request == PTRACE_SYSEMU_SINGLESTEP) | |
594 | set_tsk_thread_flag(child, TIF_SYSCALL_EMU); | |
595 | else | |
596 | clear_tsk_thread_flag(child, TIF_SYSCALL_EMU); | |
597 | #endif | |
598 | ||
5b88abbf RM |
599 | if (is_singleblock(request)) { |
600 | if (unlikely(!arch_has_block_step())) | |
601 | return -EIO; | |
602 | user_enable_block_step(child); | |
603 | } else if (is_singlestep(request) || is_sysemu_singlestep(request)) { | |
36df29d7 RM |
604 | if (unlikely(!arch_has_single_step())) |
605 | return -EIO; | |
606 | user_enable_single_step(child); | |
3a709703 | 607 | } else { |
36df29d7 | 608 | user_disable_single_step(child); |
3a709703 | 609 | } |
36df29d7 RM |
610 | |
611 | child->exit_code = data; | |
0666fb51 | 612 | wake_up_state(child, __TASK_TRACED); |
36df29d7 RM |
613 | |
614 | return 0; | |
615 | } | |
616 | ||
2225a122 SS |
617 | #ifdef CONFIG_HAVE_ARCH_TRACEHOOK |
618 | ||
619 | static const struct user_regset * | |
620 | find_regset(const struct user_regset_view *view, unsigned int type) | |
621 | { | |
622 | const struct user_regset *regset; | |
623 | int n; | |
624 | ||
625 | for (n = 0; n < view->n; ++n) { | |
626 | regset = view->regsets + n; | |
627 | if (regset->core_note_type == type) | |
628 | return regset; | |
629 | } | |
630 | ||
631 | return NULL; | |
632 | } | |
633 | ||
634 | static int ptrace_regset(struct task_struct *task, int req, unsigned int type, | |
635 | struct iovec *kiov) | |
636 | { | |
637 | const struct user_regset_view *view = task_user_regset_view(task); | |
638 | const struct user_regset *regset = find_regset(view, type); | |
639 | int regset_no; | |
640 | ||
641 | if (!regset || (kiov->iov_len % regset->size) != 0) | |
c6a0dd7e | 642 | return -EINVAL; |
2225a122 SS |
643 | |
644 | regset_no = regset - view->regsets; | |
645 | kiov->iov_len = min(kiov->iov_len, | |
646 | (__kernel_size_t) (regset->n * regset->size)); | |
647 | ||
648 | if (req == PTRACE_GETREGSET) | |
649 | return copy_regset_to_user(task, view, regset_no, 0, | |
650 | kiov->iov_len, kiov->iov_base); | |
651 | else | |
652 | return copy_regset_from_user(task, view, regset_no, 0, | |
653 | kiov->iov_len, kiov->iov_base); | |
654 | } | |
655 | ||
656 | #endif | |
657 | ||
1da177e4 | 658 | int ptrace_request(struct task_struct *child, long request, |
4abf9869 | 659 | unsigned long addr, unsigned long data) |
1da177e4 LT |
660 | { |
661 | int ret = -EIO; | |
e16b2781 | 662 | siginfo_t siginfo; |
9fed81dc NK |
663 | void __user *datavp = (void __user *) data; |
664 | unsigned long __user *datalp = datavp; | |
1da177e4 LT |
665 | |
666 | switch (request) { | |
16c3e389 RM |
667 | case PTRACE_PEEKTEXT: |
668 | case PTRACE_PEEKDATA: | |
669 | return generic_ptrace_peekdata(child, addr, data); | |
670 | case PTRACE_POKETEXT: | |
671 | case PTRACE_POKEDATA: | |
672 | return generic_ptrace_pokedata(child, addr, data); | |
673 | ||
1da177e4 LT |
674 | #ifdef PTRACE_OLDSETOPTIONS |
675 | case PTRACE_OLDSETOPTIONS: | |
676 | #endif | |
677 | case PTRACE_SETOPTIONS: | |
678 | ret = ptrace_setoptions(child, data); | |
679 | break; | |
680 | case PTRACE_GETEVENTMSG: | |
9fed81dc | 681 | ret = put_user(child->ptrace_message, datalp); |
1da177e4 | 682 | break; |
e16b2781 | 683 | |
1da177e4 | 684 | case PTRACE_GETSIGINFO: |
e16b2781 RM |
685 | ret = ptrace_getsiginfo(child, &siginfo); |
686 | if (!ret) | |
9fed81dc | 687 | ret = copy_siginfo_to_user(datavp, &siginfo); |
1da177e4 | 688 | break; |
e16b2781 | 689 | |
1da177e4 | 690 | case PTRACE_SETSIGINFO: |
9fed81dc | 691 | if (copy_from_user(&siginfo, datavp, sizeof siginfo)) |
e16b2781 RM |
692 | ret = -EFAULT; |
693 | else | |
694 | ret = ptrace_setsiginfo(child, &siginfo); | |
1da177e4 | 695 | break; |
e16b2781 | 696 | |
1bcf5482 AD |
697 | case PTRACE_DETACH: /* detach a process that was attached. */ |
698 | ret = ptrace_detach(child, data); | |
699 | break; | |
36df29d7 | 700 | |
9c1a1259 MF |
701 | #ifdef CONFIG_BINFMT_ELF_FDPIC |
702 | case PTRACE_GETFDPIC: { | |
e0129ef9 | 703 | struct mm_struct *mm = get_task_mm(child); |
9c1a1259 MF |
704 | unsigned long tmp = 0; |
705 | ||
e0129ef9 ON |
706 | ret = -ESRCH; |
707 | if (!mm) | |
708 | break; | |
709 | ||
9c1a1259 MF |
710 | switch (addr) { |
711 | case PTRACE_GETFDPIC_EXEC: | |
e0129ef9 | 712 | tmp = mm->context.exec_fdpic_loadmap; |
9c1a1259 MF |
713 | break; |
714 | case PTRACE_GETFDPIC_INTERP: | |
e0129ef9 | 715 | tmp = mm->context.interp_fdpic_loadmap; |
9c1a1259 MF |
716 | break; |
717 | default: | |
718 | break; | |
719 | } | |
e0129ef9 | 720 | mmput(mm); |
9c1a1259 | 721 | |
9fed81dc | 722 | ret = put_user(tmp, datalp); |
9c1a1259 MF |
723 | break; |
724 | } | |
725 | #endif | |
726 | ||
36df29d7 RM |
727 | #ifdef PTRACE_SINGLESTEP |
728 | case PTRACE_SINGLESTEP: | |
729 | #endif | |
5b88abbf RM |
730 | #ifdef PTRACE_SINGLEBLOCK |
731 | case PTRACE_SINGLEBLOCK: | |
732 | #endif | |
36df29d7 RM |
733 | #ifdef PTRACE_SYSEMU |
734 | case PTRACE_SYSEMU: | |
735 | case PTRACE_SYSEMU_SINGLESTEP: | |
736 | #endif | |
737 | case PTRACE_SYSCALL: | |
738 | case PTRACE_CONT: | |
739 | return ptrace_resume(child, request, data); | |
740 | ||
741 | case PTRACE_KILL: | |
742 | if (child->exit_state) /* already dead */ | |
743 | return 0; | |
744 | return ptrace_resume(child, request, SIGKILL); | |
745 | ||
2225a122 SS |
746 | #ifdef CONFIG_HAVE_ARCH_TRACEHOOK |
747 | case PTRACE_GETREGSET: | |
748 | case PTRACE_SETREGSET: | |
749 | { | |
750 | struct iovec kiov; | |
9fed81dc | 751 | struct iovec __user *uiov = datavp; |
2225a122 SS |
752 | |
753 | if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov))) | |
754 | return -EFAULT; | |
755 | ||
756 | if (__get_user(kiov.iov_base, &uiov->iov_base) || | |
757 | __get_user(kiov.iov_len, &uiov->iov_len)) | |
758 | return -EFAULT; | |
759 | ||
760 | ret = ptrace_regset(child, request, addr, &kiov); | |
761 | if (!ret) | |
762 | ret = __put_user(kiov.iov_len, &uiov->iov_len); | |
763 | break; | |
764 | } | |
765 | #endif | |
1da177e4 LT |
766 | default: |
767 | break; | |
768 | } | |
769 | ||
770 | return ret; | |
771 | } | |
481bed45 | 772 | |
8053bdd5 | 773 | static struct task_struct *ptrace_get_task_struct(pid_t pid) |
6b9c7ed8 CH |
774 | { |
775 | struct task_struct *child; | |
481bed45 | 776 | |
8053bdd5 | 777 | rcu_read_lock(); |
228ebcbe | 778 | child = find_task_by_vpid(pid); |
481bed45 CH |
779 | if (child) |
780 | get_task_struct(child); | |
8053bdd5 | 781 | rcu_read_unlock(); |
f400e198 | 782 | |
481bed45 | 783 | if (!child) |
6b9c7ed8 CH |
784 | return ERR_PTR(-ESRCH); |
785 | return child; | |
481bed45 CH |
786 | } |
787 | ||
0ac15559 CH |
788 | #ifndef arch_ptrace_attach |
789 | #define arch_ptrace_attach(child) do { } while (0) | |
790 | #endif | |
791 | ||
4abf9869 NK |
792 | SYSCALL_DEFINE4(ptrace, long, request, long, pid, unsigned long, addr, |
793 | unsigned long, data) | |
481bed45 CH |
794 | { |
795 | struct task_struct *child; | |
796 | long ret; | |
797 | ||
6b9c7ed8 CH |
798 | if (request == PTRACE_TRACEME) { |
799 | ret = ptrace_traceme(); | |
6ea6dd93 HS |
800 | if (!ret) |
801 | arch_ptrace_attach(current); | |
481bed45 | 802 | goto out; |
6b9c7ed8 CH |
803 | } |
804 | ||
805 | child = ptrace_get_task_struct(pid); | |
806 | if (IS_ERR(child)) { | |
807 | ret = PTR_ERR(child); | |
808 | goto out; | |
809 | } | |
481bed45 | 810 | |
3544d72a TH |
811 | if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) { |
812 | ret = ptrace_attach(child, request, data); | |
0ac15559 CH |
813 | /* |
814 | * Some architectures need to do book-keeping after | |
815 | * a ptrace attach. | |
816 | */ | |
817 | if (!ret) | |
818 | arch_ptrace_attach(child); | |
005f18df | 819 | goto out_put_task_struct; |
481bed45 CH |
820 | } |
821 | ||
822 | ret = ptrace_check_attach(child, request == PTRACE_KILL); | |
823 | if (ret < 0) | |
824 | goto out_put_task_struct; | |
825 | ||
826 | ret = arch_ptrace(child, request, addr, data); | |
481bed45 CH |
827 | |
828 | out_put_task_struct: | |
829 | put_task_struct(child); | |
830 | out: | |
481bed45 CH |
831 | return ret; |
832 | } | |
76647323 | 833 | |
4abf9869 NK |
834 | int generic_ptrace_peekdata(struct task_struct *tsk, unsigned long addr, |
835 | unsigned long data) | |
76647323 AD |
836 | { |
837 | unsigned long tmp; | |
838 | int copied; | |
839 | ||
840 | copied = access_process_vm(tsk, addr, &tmp, sizeof(tmp), 0); | |
841 | if (copied != sizeof(tmp)) | |
842 | return -EIO; | |
843 | return put_user(tmp, (unsigned long __user *)data); | |
844 | } | |
f284ce72 | 845 | |
4abf9869 NK |
846 | int generic_ptrace_pokedata(struct task_struct *tsk, unsigned long addr, |
847 | unsigned long data) | |
f284ce72 AD |
848 | { |
849 | int copied; | |
850 | ||
851 | copied = access_process_vm(tsk, addr, &data, sizeof(data), 1); | |
852 | return (copied == sizeof(data)) ? 0 : -EIO; | |
853 | } | |
032d82d9 | 854 | |
96b8936a | 855 | #if defined CONFIG_COMPAT |
032d82d9 RM |
856 | #include <linux/compat.h> |
857 | ||
858 | int compat_ptrace_request(struct task_struct *child, compat_long_t request, | |
859 | compat_ulong_t addr, compat_ulong_t data) | |
860 | { | |
861 | compat_ulong_t __user *datap = compat_ptr(data); | |
862 | compat_ulong_t word; | |
e16b2781 | 863 | siginfo_t siginfo; |
032d82d9 RM |
864 | int ret; |
865 | ||
866 | switch (request) { | |
867 | case PTRACE_PEEKTEXT: | |
868 | case PTRACE_PEEKDATA: | |
869 | ret = access_process_vm(child, addr, &word, sizeof(word), 0); | |
870 | if (ret != sizeof(word)) | |
871 | ret = -EIO; | |
872 | else | |
873 | ret = put_user(word, datap); | |
874 | break; | |
875 | ||
876 | case PTRACE_POKETEXT: | |
877 | case PTRACE_POKEDATA: | |
878 | ret = access_process_vm(child, addr, &data, sizeof(data), 1); | |
879 | ret = (ret != sizeof(data) ? -EIO : 0); | |
880 | break; | |
881 | ||
882 | case PTRACE_GETEVENTMSG: | |
883 | ret = put_user((compat_ulong_t) child->ptrace_message, datap); | |
884 | break; | |
885 | ||
e16b2781 RM |
886 | case PTRACE_GETSIGINFO: |
887 | ret = ptrace_getsiginfo(child, &siginfo); | |
888 | if (!ret) | |
889 | ret = copy_siginfo_to_user32( | |
890 | (struct compat_siginfo __user *) datap, | |
891 | &siginfo); | |
892 | break; | |
893 | ||
894 | case PTRACE_SETSIGINFO: | |
895 | memset(&siginfo, 0, sizeof siginfo); | |
896 | if (copy_siginfo_from_user32( | |
897 | &siginfo, (struct compat_siginfo __user *) datap)) | |
898 | ret = -EFAULT; | |
899 | else | |
900 | ret = ptrace_setsiginfo(child, &siginfo); | |
901 | break; | |
2225a122 SS |
902 | #ifdef CONFIG_HAVE_ARCH_TRACEHOOK |
903 | case PTRACE_GETREGSET: | |
904 | case PTRACE_SETREGSET: | |
905 | { | |
906 | struct iovec kiov; | |
907 | struct compat_iovec __user *uiov = | |
908 | (struct compat_iovec __user *) datap; | |
909 | compat_uptr_t ptr; | |
910 | compat_size_t len; | |
911 | ||
912 | if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov))) | |
913 | return -EFAULT; | |
914 | ||
915 | if (__get_user(ptr, &uiov->iov_base) || | |
916 | __get_user(len, &uiov->iov_len)) | |
917 | return -EFAULT; | |
918 | ||
919 | kiov.iov_base = compat_ptr(ptr); | |
920 | kiov.iov_len = len; | |
921 | ||
922 | ret = ptrace_regset(child, request, addr, &kiov); | |
923 | if (!ret) | |
924 | ret = __put_user(kiov.iov_len, &uiov->iov_len); | |
925 | break; | |
926 | } | |
927 | #endif | |
e16b2781 | 928 | |
032d82d9 RM |
929 | default: |
930 | ret = ptrace_request(child, request, addr, data); | |
931 | } | |
932 | ||
933 | return ret; | |
934 | } | |
c269f196 | 935 | |
c269f196 RM |
936 | asmlinkage long compat_sys_ptrace(compat_long_t request, compat_long_t pid, |
937 | compat_long_t addr, compat_long_t data) | |
938 | { | |
939 | struct task_struct *child; | |
940 | long ret; | |
941 | ||
c269f196 RM |
942 | if (request == PTRACE_TRACEME) { |
943 | ret = ptrace_traceme(); | |
944 | goto out; | |
945 | } | |
946 | ||
947 | child = ptrace_get_task_struct(pid); | |
948 | if (IS_ERR(child)) { | |
949 | ret = PTR_ERR(child); | |
950 | goto out; | |
951 | } | |
952 | ||
3544d72a TH |
953 | if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) { |
954 | ret = ptrace_attach(child, request, data); | |
c269f196 RM |
955 | /* |
956 | * Some architectures need to do book-keeping after | |
957 | * a ptrace attach. | |
958 | */ | |
959 | if (!ret) | |
960 | arch_ptrace_attach(child); | |
961 | goto out_put_task_struct; | |
962 | } | |
963 | ||
964 | ret = ptrace_check_attach(child, request == PTRACE_KILL); | |
965 | if (!ret) | |
966 | ret = compat_arch_ptrace(child, request, addr, data); | |
967 | ||
968 | out_put_task_struct: | |
969 | put_task_struct(child); | |
970 | out: | |
c269f196 RM |
971 | return ret; |
972 | } | |
96b8936a | 973 | #endif /* CONFIG_COMPAT */ |
bf26c018 FW |
974 | |
975 | #ifdef CONFIG_HAVE_HW_BREAKPOINT | |
976 | int ptrace_get_breakpoints(struct task_struct *tsk) | |
977 | { | |
978 | if (atomic_inc_not_zero(&tsk->ptrace_bp_refcnt)) | |
979 | return 0; | |
980 | ||
981 | return -1; | |
982 | } | |
983 | ||
984 | void ptrace_put_breakpoints(struct task_struct *tsk) | |
985 | { | |
986 | if (atomic_dec_and_test(&tsk->ptrace_bp_refcnt)) | |
987 | flush_ptrace_hw_breakpoint(tsk); | |
988 | } | |
989 | #endif /* CONFIG_HAVE_HW_BREAKPOINT */ |