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 | |
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 | ||
100 | /* | |
101 | * Check that we have indeed attached to the thing.. | |
102 | */ | |
103 | int ptrace_check_attach(struct task_struct *child, int kill) | |
104 | { | |
105 | int ret = -ESRCH; | |
106 | ||
107 | /* | |
108 | * We take the read lock around doing both checks to close a | |
109 | * possible race where someone else was tracing our child and | |
110 | * detached between these two checks. After this locked check, | |
111 | * we are sure that this is our traced child and that can only | |
112 | * be changed by us so it's not changing right after this. | |
113 | */ | |
114 | read_lock(&tasklist_lock); | |
c0c0b649 | 115 | if ((child->ptrace & PT_PTRACED) && child->parent == current) { |
c0c0b649 ON |
116 | /* |
117 | * child->sighand can't be NULL, release_task() | |
118 | * does ptrace_unlink() before __exit_signal(). | |
119 | */ | |
1da177e4 | 120 | spin_lock_irq(&child->sighand->siglock); |
321fb561 ON |
121 | WARN_ON_ONCE(task_is_stopped(child)); |
122 | if (task_is_traced(child) || kill) | |
123 | ret = 0; | |
1da177e4 LT |
124 | spin_unlock_irq(&child->sighand->siglock); |
125 | } | |
126 | read_unlock(&tasklist_lock); | |
127 | ||
d9ae90ac | 128 | if (!ret && !kill) |
85ba2d86 | 129 | ret = wait_task_inactive(child, TASK_TRACED) ? 0 : -ESRCH; |
1da177e4 LT |
130 | |
131 | /* All systems go.. */ | |
132 | return ret; | |
133 | } | |
134 | ||
006ebb40 | 135 | int __ptrace_may_access(struct task_struct *task, unsigned int mode) |
ab8d11be | 136 | { |
c69e8d9c | 137 | const struct cred *cred = current_cred(), *tcred; |
b6dff3ec | 138 | |
df26c40e EB |
139 | /* May we inspect the given task? |
140 | * This check is used both for attaching with ptrace | |
141 | * and for allowing access to sensitive information in /proc. | |
142 | * | |
143 | * ptrace_attach denies several cases that /proc allows | |
144 | * because setting up the necessary parent/child relationship | |
145 | * or halting the specified task is impossible. | |
146 | */ | |
147 | int dumpable = 0; | |
148 | /* Don't let security modules deny introspection */ | |
149 | if (task == current) | |
150 | return 0; | |
c69e8d9c DH |
151 | rcu_read_lock(); |
152 | tcred = __task_cred(task); | |
8409cca7 SH |
153 | if (cred->user->user_ns == tcred->user->user_ns && |
154 | (cred->uid == tcred->euid && | |
155 | cred->uid == tcred->suid && | |
156 | cred->uid == tcred->uid && | |
157 | cred->gid == tcred->egid && | |
158 | cred->gid == tcred->sgid && | |
159 | cred->gid == tcred->gid)) | |
160 | goto ok; | |
161 | if (ns_capable(tcred->user->user_ns, CAP_SYS_PTRACE)) | |
162 | goto ok; | |
163 | rcu_read_unlock(); | |
164 | return -EPERM; | |
165 | ok: | |
c69e8d9c | 166 | rcu_read_unlock(); |
ab8d11be | 167 | smp_rmb(); |
df26c40e | 168 | if (task->mm) |
6c5d5238 | 169 | dumpable = get_dumpable(task->mm); |
8409cca7 | 170 | if (!dumpable && !task_ns_capable(task, CAP_SYS_PTRACE)) |
ab8d11be MS |
171 | return -EPERM; |
172 | ||
9e48858f | 173 | return security_ptrace_access_check(task, mode); |
ab8d11be MS |
174 | } |
175 | ||
006ebb40 | 176 | bool ptrace_may_access(struct task_struct *task, unsigned int mode) |
ab8d11be MS |
177 | { |
178 | int err; | |
179 | task_lock(task); | |
006ebb40 | 180 | err = __ptrace_may_access(task, mode); |
ab8d11be | 181 | task_unlock(task); |
3a709703 | 182 | return !err; |
ab8d11be MS |
183 | } |
184 | ||
e3e89cc5 | 185 | static int ptrace_attach(struct task_struct *task) |
1da177e4 LT |
186 | { |
187 | int retval; | |
f5b40e36 | 188 | |
a5cb013d AV |
189 | audit_ptrace(task); |
190 | ||
1da177e4 | 191 | retval = -EPERM; |
b79b7ba9 ON |
192 | if (unlikely(task->flags & PF_KTHREAD)) |
193 | goto out; | |
bac0abd6 | 194 | if (same_thread_group(task, current)) |
f5b40e36 LT |
195 | goto out; |
196 | ||
f2f0b00a ON |
197 | /* |
198 | * Protect exec's credential calculations against our interference; | |
5e751e99 DH |
199 | * interference; SUID, SGID and LSM creds get determined differently |
200 | * under ptrace. | |
d84f4f99 | 201 | */ |
793285fc | 202 | retval = -ERESTARTNOINTR; |
9b1bf12d | 203 | if (mutex_lock_interruptible(&task->signal->cred_guard_mutex)) |
d84f4f99 | 204 | goto out; |
f5b40e36 | 205 | |
4b105cbb | 206 | task_lock(task); |
006ebb40 | 207 | retval = __ptrace_may_access(task, PTRACE_MODE_ATTACH); |
4b105cbb | 208 | task_unlock(task); |
1da177e4 | 209 | if (retval) |
4b105cbb | 210 | goto unlock_creds; |
1da177e4 | 211 | |
4b105cbb | 212 | write_lock_irq(&tasklist_lock); |
b79b7ba9 ON |
213 | retval = -EPERM; |
214 | if (unlikely(task->exit_state)) | |
4b105cbb | 215 | goto unlock_tasklist; |
f2f0b00a | 216 | if (task->ptrace) |
4b105cbb | 217 | goto unlock_tasklist; |
b79b7ba9 | 218 | |
f2f0b00a | 219 | task->ptrace = PT_PTRACED; |
8409cca7 | 220 | if (task_ns_capable(task, CAP_SYS_PTRACE)) |
1da177e4 | 221 | task->ptrace |= PT_PTRACE_CAP; |
1da177e4 | 222 | |
1da177e4 | 223 | __ptrace_link(task, current); |
33e9fc7d | 224 | send_sig_info(SIGSTOP, SEND_SIG_FORCED, task); |
b79b7ba9 | 225 | |
d79fdd6d TH |
226 | spin_lock(&task->sighand->siglock); |
227 | ||
228 | /* | |
a8f072c1 | 229 | * If the task is already STOPPED, set JOBCTL_STOP_PENDING and |
d79fdd6d TH |
230 | * TRAPPING, and kick it so that it transits to TRACED. TRAPPING |
231 | * will be cleared if the child completes the transition or any | |
232 | * event which clears the group stop states happens. We'll wait | |
233 | * for the transition to complete before returning from this | |
234 | * function. | |
235 | * | |
236 | * This hides STOPPED -> RUNNING -> TRACED transition from the | |
237 | * attaching thread but a different thread in the same group can | |
238 | * still observe the transient RUNNING state. IOW, if another | |
239 | * thread's WNOHANG wait(2) on the stopped tracee races against | |
240 | * ATTACH, the wait(2) may fail due to the transient RUNNING. | |
241 | * | |
242 | * The following task_is_stopped() test is safe as both transitions | |
243 | * in and out of STOPPED are protected by siglock. | |
244 | */ | |
245 | if (task_is_stopped(task)) { | |
a8f072c1 | 246 | task->jobctl |= JOBCTL_STOP_PENDING | JOBCTL_TRAPPING; |
d79fdd6d | 247 | signal_wake_up(task, 1); |
d79fdd6d TH |
248 | } |
249 | ||
250 | spin_unlock(&task->sighand->siglock); | |
251 | ||
b79b7ba9 | 252 | retval = 0; |
4b105cbb ON |
253 | unlock_tasklist: |
254 | write_unlock_irq(&tasklist_lock); | |
255 | unlock_creds: | |
9b1bf12d | 256 | mutex_unlock(&task->signal->cred_guard_mutex); |
f5b40e36 | 257 | out: |
0b1007c3 | 258 | if (!retval) |
d79fdd6d | 259 | wait_event(current->signal->wait_chldexit, |
a8f072c1 | 260 | !(task->jobctl & JOBCTL_TRAPPING)); |
1da177e4 LT |
261 | return retval; |
262 | } | |
263 | ||
f2f0b00a ON |
264 | /** |
265 | * ptrace_traceme -- helper for PTRACE_TRACEME | |
266 | * | |
267 | * Performs checks and sets PT_PTRACED. | |
268 | * Should be used by all ptrace implementations for PTRACE_TRACEME. | |
269 | */ | |
e3e89cc5 | 270 | static int ptrace_traceme(void) |
f2f0b00a ON |
271 | { |
272 | int ret = -EPERM; | |
273 | ||
4b105cbb ON |
274 | write_lock_irq(&tasklist_lock); |
275 | /* Are we already being traced? */ | |
f2f0b00a | 276 | if (!current->ptrace) { |
f2f0b00a | 277 | ret = security_ptrace_traceme(current->parent); |
f2f0b00a ON |
278 | /* |
279 | * Check PF_EXITING to ensure ->real_parent has not passed | |
280 | * exit_ptrace(). Otherwise we don't report the error but | |
281 | * pretend ->real_parent untraces us right after return. | |
282 | */ | |
283 | if (!ret && !(current->real_parent->flags & PF_EXITING)) { | |
284 | current->ptrace = PT_PTRACED; | |
285 | __ptrace_link(current, current->real_parent); | |
286 | } | |
f2f0b00a | 287 | } |
4b105cbb ON |
288 | write_unlock_irq(&tasklist_lock); |
289 | ||
f2f0b00a ON |
290 | return ret; |
291 | } | |
292 | ||
39c626ae ON |
293 | /* |
294 | * Called with irqs disabled, returns true if childs should reap themselves. | |
295 | */ | |
296 | static int ignoring_children(struct sighand_struct *sigh) | |
297 | { | |
298 | int ret; | |
299 | spin_lock(&sigh->siglock); | |
300 | ret = (sigh->action[SIGCHLD-1].sa.sa_handler == SIG_IGN) || | |
301 | (sigh->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT); | |
302 | spin_unlock(&sigh->siglock); | |
303 | return ret; | |
304 | } | |
305 | ||
306 | /* | |
307 | * Called with tasklist_lock held for writing. | |
308 | * Unlink a traced task, and clean it up if it was a traced zombie. | |
309 | * Return true if it needs to be reaped with release_task(). | |
310 | * (We can't call release_task() here because we already hold tasklist_lock.) | |
311 | * | |
312 | * If it's a zombie, our attachedness prevented normal parent notification | |
313 | * or self-reaping. Do notification now if it would have happened earlier. | |
314 | * If it should reap itself, return true. | |
315 | * | |
a7f0765e ON |
316 | * If it's our own child, there is no notification to do. But if our normal |
317 | * children self-reap, then this child was prevented by ptrace and we must | |
318 | * reap it now, in that case we must also wake up sub-threads sleeping in | |
319 | * do_wait(). | |
39c626ae ON |
320 | */ |
321 | static bool __ptrace_detach(struct task_struct *tracer, struct task_struct *p) | |
322 | { | |
323 | __ptrace_unlink(p); | |
324 | ||
325 | if (p->exit_state == EXIT_ZOMBIE) { | |
326 | if (!task_detached(p) && thread_group_empty(p)) { | |
327 | if (!same_thread_group(p->real_parent, tracer)) | |
328 | do_notify_parent(p, p->exit_signal); | |
a7f0765e ON |
329 | else if (ignoring_children(tracer->sighand)) { |
330 | __wake_up_parent(p, tracer); | |
39c626ae | 331 | p->exit_signal = -1; |
a7f0765e | 332 | } |
39c626ae ON |
333 | } |
334 | if (task_detached(p)) { | |
335 | /* Mark it as in the process of being reaped. */ | |
336 | p->exit_state = EXIT_DEAD; | |
337 | return true; | |
338 | } | |
339 | } | |
340 | ||
341 | return false; | |
342 | } | |
343 | ||
e3e89cc5 | 344 | static int ptrace_detach(struct task_struct *child, unsigned int data) |
1da177e4 | 345 | { |
39c626ae | 346 | bool dead = false; |
4576145c | 347 | |
7ed20e1a | 348 | if (!valid_signal(data)) |
5ecfbae0 | 349 | return -EIO; |
1da177e4 LT |
350 | |
351 | /* Architecture-specific hardware disable .. */ | |
352 | ptrace_disable(child); | |
7d941432 | 353 | clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); |
1da177e4 | 354 | |
95c3eb76 | 355 | write_lock_irq(&tasklist_lock); |
39c626ae ON |
356 | /* |
357 | * This child can be already killed. Make sure de_thread() or | |
358 | * our sub-thread doing do_wait() didn't do release_task() yet. | |
359 | */ | |
95c3eb76 ON |
360 | if (child->ptrace) { |
361 | child->exit_code = data; | |
4576145c | 362 | dead = __ptrace_detach(current, child); |
95c3eb76 | 363 | } |
1da177e4 LT |
364 | write_unlock_irq(&tasklist_lock); |
365 | ||
4576145c ON |
366 | if (unlikely(dead)) |
367 | release_task(child); | |
368 | ||
1da177e4 LT |
369 | return 0; |
370 | } | |
371 | ||
39c626ae | 372 | /* |
c7e49c14 ON |
373 | * Detach all tasks we were using ptrace on. Called with tasklist held |
374 | * for writing, and returns with it held too. But note it can release | |
375 | * and reacquire the lock. | |
39c626ae ON |
376 | */ |
377 | void exit_ptrace(struct task_struct *tracer) | |
c4b5ed25 NK |
378 | __releases(&tasklist_lock) |
379 | __acquires(&tasklist_lock) | |
39c626ae ON |
380 | { |
381 | struct task_struct *p, *n; | |
382 | LIST_HEAD(ptrace_dead); | |
383 | ||
c7e49c14 ON |
384 | if (likely(list_empty(&tracer->ptraced))) |
385 | return; | |
386 | ||
39c626ae ON |
387 | list_for_each_entry_safe(p, n, &tracer->ptraced, ptrace_entry) { |
388 | if (__ptrace_detach(tracer, p)) | |
389 | list_add(&p->ptrace_entry, &ptrace_dead); | |
390 | } | |
39c626ae | 391 | |
c7e49c14 | 392 | write_unlock_irq(&tasklist_lock); |
39c626ae ON |
393 | BUG_ON(!list_empty(&tracer->ptraced)); |
394 | ||
395 | list_for_each_entry_safe(p, n, &ptrace_dead, ptrace_entry) { | |
396 | list_del_init(&p->ptrace_entry); | |
397 | release_task(p); | |
398 | } | |
c7e49c14 ON |
399 | |
400 | write_lock_irq(&tasklist_lock); | |
39c626ae ON |
401 | } |
402 | ||
1da177e4 LT |
403 | int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len) |
404 | { | |
405 | int copied = 0; | |
406 | ||
407 | while (len > 0) { | |
408 | char buf[128]; | |
409 | int this_len, retval; | |
410 | ||
411 | this_len = (len > sizeof(buf)) ? sizeof(buf) : len; | |
412 | retval = access_process_vm(tsk, src, buf, this_len, 0); | |
413 | if (!retval) { | |
414 | if (copied) | |
415 | break; | |
416 | return -EIO; | |
417 | } | |
418 | if (copy_to_user(dst, buf, retval)) | |
419 | return -EFAULT; | |
420 | copied += retval; | |
421 | src += retval; | |
422 | dst += retval; | |
3a709703 | 423 | len -= retval; |
1da177e4 LT |
424 | } |
425 | return copied; | |
426 | } | |
427 | ||
428 | int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len) | |
429 | { | |
430 | int copied = 0; | |
431 | ||
432 | while (len > 0) { | |
433 | char buf[128]; | |
434 | int this_len, retval; | |
435 | ||
436 | this_len = (len > sizeof(buf)) ? sizeof(buf) : len; | |
437 | if (copy_from_user(buf, src, this_len)) | |
438 | return -EFAULT; | |
439 | retval = access_process_vm(tsk, dst, buf, this_len, 1); | |
440 | if (!retval) { | |
441 | if (copied) | |
442 | break; | |
443 | return -EIO; | |
444 | } | |
445 | copied += retval; | |
446 | src += retval; | |
447 | dst += retval; | |
3a709703 | 448 | len -= retval; |
1da177e4 LT |
449 | } |
450 | return copied; | |
451 | } | |
452 | ||
4abf9869 | 453 | static int ptrace_setoptions(struct task_struct *child, unsigned long data) |
1da177e4 LT |
454 | { |
455 | child->ptrace &= ~PT_TRACE_MASK; | |
456 | ||
457 | if (data & PTRACE_O_TRACESYSGOOD) | |
458 | child->ptrace |= PT_TRACESYSGOOD; | |
459 | ||
460 | if (data & PTRACE_O_TRACEFORK) | |
461 | child->ptrace |= PT_TRACE_FORK; | |
462 | ||
463 | if (data & PTRACE_O_TRACEVFORK) | |
464 | child->ptrace |= PT_TRACE_VFORK; | |
465 | ||
466 | if (data & PTRACE_O_TRACECLONE) | |
467 | child->ptrace |= PT_TRACE_CLONE; | |
468 | ||
469 | if (data & PTRACE_O_TRACEEXEC) | |
470 | child->ptrace |= PT_TRACE_EXEC; | |
471 | ||
472 | if (data & PTRACE_O_TRACEVFORKDONE) | |
473 | child->ptrace |= PT_TRACE_VFORK_DONE; | |
474 | ||
475 | if (data & PTRACE_O_TRACEEXIT) | |
476 | child->ptrace |= PT_TRACE_EXIT; | |
477 | ||
478 | return (data & ~PTRACE_O_MASK) ? -EINVAL : 0; | |
479 | } | |
480 | ||
e16b2781 | 481 | static int ptrace_getsiginfo(struct task_struct *child, siginfo_t *info) |
1da177e4 | 482 | { |
e4961254 | 483 | unsigned long flags; |
1da177e4 LT |
484 | int error = -ESRCH; |
485 | ||
e4961254 | 486 | if (lock_task_sighand(child, &flags)) { |
1da177e4 | 487 | error = -EINVAL; |
1da177e4 | 488 | if (likely(child->last_siginfo != NULL)) { |
e16b2781 | 489 | *info = *child->last_siginfo; |
1da177e4 LT |
490 | error = 0; |
491 | } | |
e4961254 | 492 | unlock_task_sighand(child, &flags); |
1da177e4 | 493 | } |
1da177e4 LT |
494 | return error; |
495 | } | |
496 | ||
e16b2781 | 497 | static int ptrace_setsiginfo(struct task_struct *child, const siginfo_t *info) |
1da177e4 | 498 | { |
e4961254 | 499 | unsigned long flags; |
1da177e4 LT |
500 | int error = -ESRCH; |
501 | ||
e4961254 | 502 | if (lock_task_sighand(child, &flags)) { |
1da177e4 | 503 | error = -EINVAL; |
1da177e4 | 504 | if (likely(child->last_siginfo != NULL)) { |
e16b2781 | 505 | *child->last_siginfo = *info; |
1da177e4 LT |
506 | error = 0; |
507 | } | |
e4961254 | 508 | unlock_task_sighand(child, &flags); |
1da177e4 | 509 | } |
1da177e4 LT |
510 | return error; |
511 | } | |
512 | ||
36df29d7 RM |
513 | |
514 | #ifdef PTRACE_SINGLESTEP | |
515 | #define is_singlestep(request) ((request) == PTRACE_SINGLESTEP) | |
516 | #else | |
517 | #define is_singlestep(request) 0 | |
518 | #endif | |
519 | ||
5b88abbf RM |
520 | #ifdef PTRACE_SINGLEBLOCK |
521 | #define is_singleblock(request) ((request) == PTRACE_SINGLEBLOCK) | |
522 | #else | |
523 | #define is_singleblock(request) 0 | |
524 | #endif | |
525 | ||
36df29d7 RM |
526 | #ifdef PTRACE_SYSEMU |
527 | #define is_sysemu_singlestep(request) ((request) == PTRACE_SYSEMU_SINGLESTEP) | |
528 | #else | |
529 | #define is_sysemu_singlestep(request) 0 | |
530 | #endif | |
531 | ||
4abf9869 NK |
532 | static int ptrace_resume(struct task_struct *child, long request, |
533 | unsigned long data) | |
36df29d7 RM |
534 | { |
535 | if (!valid_signal(data)) | |
536 | return -EIO; | |
537 | ||
538 | if (request == PTRACE_SYSCALL) | |
539 | set_tsk_thread_flag(child, TIF_SYSCALL_TRACE); | |
540 | else | |
541 | clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); | |
542 | ||
543 | #ifdef TIF_SYSCALL_EMU | |
544 | if (request == PTRACE_SYSEMU || request == PTRACE_SYSEMU_SINGLESTEP) | |
545 | set_tsk_thread_flag(child, TIF_SYSCALL_EMU); | |
546 | else | |
547 | clear_tsk_thread_flag(child, TIF_SYSCALL_EMU); | |
548 | #endif | |
549 | ||
5b88abbf RM |
550 | if (is_singleblock(request)) { |
551 | if (unlikely(!arch_has_block_step())) | |
552 | return -EIO; | |
553 | user_enable_block_step(child); | |
554 | } else if (is_singlestep(request) || is_sysemu_singlestep(request)) { | |
36df29d7 RM |
555 | if (unlikely(!arch_has_single_step())) |
556 | return -EIO; | |
557 | user_enable_single_step(child); | |
3a709703 | 558 | } else { |
36df29d7 | 559 | user_disable_single_step(child); |
3a709703 | 560 | } |
36df29d7 RM |
561 | |
562 | child->exit_code = data; | |
0666fb51 | 563 | wake_up_state(child, __TASK_TRACED); |
36df29d7 RM |
564 | |
565 | return 0; | |
566 | } | |
567 | ||
2225a122 SS |
568 | #ifdef CONFIG_HAVE_ARCH_TRACEHOOK |
569 | ||
570 | static const struct user_regset * | |
571 | find_regset(const struct user_regset_view *view, unsigned int type) | |
572 | { | |
573 | const struct user_regset *regset; | |
574 | int n; | |
575 | ||
576 | for (n = 0; n < view->n; ++n) { | |
577 | regset = view->regsets + n; | |
578 | if (regset->core_note_type == type) | |
579 | return regset; | |
580 | } | |
581 | ||
582 | return NULL; | |
583 | } | |
584 | ||
585 | static int ptrace_regset(struct task_struct *task, int req, unsigned int type, | |
586 | struct iovec *kiov) | |
587 | { | |
588 | const struct user_regset_view *view = task_user_regset_view(task); | |
589 | const struct user_regset *regset = find_regset(view, type); | |
590 | int regset_no; | |
591 | ||
592 | if (!regset || (kiov->iov_len % regset->size) != 0) | |
c6a0dd7e | 593 | return -EINVAL; |
2225a122 SS |
594 | |
595 | regset_no = regset - view->regsets; | |
596 | kiov->iov_len = min(kiov->iov_len, | |
597 | (__kernel_size_t) (regset->n * regset->size)); | |
598 | ||
599 | if (req == PTRACE_GETREGSET) | |
600 | return copy_regset_to_user(task, view, regset_no, 0, | |
601 | kiov->iov_len, kiov->iov_base); | |
602 | else | |
603 | return copy_regset_from_user(task, view, regset_no, 0, | |
604 | kiov->iov_len, kiov->iov_base); | |
605 | } | |
606 | ||
607 | #endif | |
608 | ||
1da177e4 | 609 | int ptrace_request(struct task_struct *child, long request, |
4abf9869 | 610 | unsigned long addr, unsigned long data) |
1da177e4 LT |
611 | { |
612 | int ret = -EIO; | |
e16b2781 | 613 | siginfo_t siginfo; |
9fed81dc NK |
614 | void __user *datavp = (void __user *) data; |
615 | unsigned long __user *datalp = datavp; | |
1da177e4 LT |
616 | |
617 | switch (request) { | |
16c3e389 RM |
618 | case PTRACE_PEEKTEXT: |
619 | case PTRACE_PEEKDATA: | |
620 | return generic_ptrace_peekdata(child, addr, data); | |
621 | case PTRACE_POKETEXT: | |
622 | case PTRACE_POKEDATA: | |
623 | return generic_ptrace_pokedata(child, addr, data); | |
624 | ||
1da177e4 LT |
625 | #ifdef PTRACE_OLDSETOPTIONS |
626 | case PTRACE_OLDSETOPTIONS: | |
627 | #endif | |
628 | case PTRACE_SETOPTIONS: | |
629 | ret = ptrace_setoptions(child, data); | |
630 | break; | |
631 | case PTRACE_GETEVENTMSG: | |
9fed81dc | 632 | ret = put_user(child->ptrace_message, datalp); |
1da177e4 | 633 | break; |
e16b2781 | 634 | |
1da177e4 | 635 | case PTRACE_GETSIGINFO: |
e16b2781 RM |
636 | ret = ptrace_getsiginfo(child, &siginfo); |
637 | if (!ret) | |
9fed81dc | 638 | ret = copy_siginfo_to_user(datavp, &siginfo); |
1da177e4 | 639 | break; |
e16b2781 | 640 | |
1da177e4 | 641 | case PTRACE_SETSIGINFO: |
9fed81dc | 642 | if (copy_from_user(&siginfo, datavp, sizeof siginfo)) |
e16b2781 RM |
643 | ret = -EFAULT; |
644 | else | |
645 | ret = ptrace_setsiginfo(child, &siginfo); | |
1da177e4 | 646 | break; |
e16b2781 | 647 | |
1bcf5482 AD |
648 | case PTRACE_DETACH: /* detach a process that was attached. */ |
649 | ret = ptrace_detach(child, data); | |
650 | break; | |
36df29d7 | 651 | |
9c1a1259 MF |
652 | #ifdef CONFIG_BINFMT_ELF_FDPIC |
653 | case PTRACE_GETFDPIC: { | |
e0129ef9 | 654 | struct mm_struct *mm = get_task_mm(child); |
9c1a1259 MF |
655 | unsigned long tmp = 0; |
656 | ||
e0129ef9 ON |
657 | ret = -ESRCH; |
658 | if (!mm) | |
659 | break; | |
660 | ||
9c1a1259 MF |
661 | switch (addr) { |
662 | case PTRACE_GETFDPIC_EXEC: | |
e0129ef9 | 663 | tmp = mm->context.exec_fdpic_loadmap; |
9c1a1259 MF |
664 | break; |
665 | case PTRACE_GETFDPIC_INTERP: | |
e0129ef9 | 666 | tmp = mm->context.interp_fdpic_loadmap; |
9c1a1259 MF |
667 | break; |
668 | default: | |
669 | break; | |
670 | } | |
e0129ef9 | 671 | mmput(mm); |
9c1a1259 | 672 | |
9fed81dc | 673 | ret = put_user(tmp, datalp); |
9c1a1259 MF |
674 | break; |
675 | } | |
676 | #endif | |
677 | ||
36df29d7 RM |
678 | #ifdef PTRACE_SINGLESTEP |
679 | case PTRACE_SINGLESTEP: | |
680 | #endif | |
5b88abbf RM |
681 | #ifdef PTRACE_SINGLEBLOCK |
682 | case PTRACE_SINGLEBLOCK: | |
683 | #endif | |
36df29d7 RM |
684 | #ifdef PTRACE_SYSEMU |
685 | case PTRACE_SYSEMU: | |
686 | case PTRACE_SYSEMU_SINGLESTEP: | |
687 | #endif | |
688 | case PTRACE_SYSCALL: | |
689 | case PTRACE_CONT: | |
690 | return ptrace_resume(child, request, data); | |
691 | ||
692 | case PTRACE_KILL: | |
693 | if (child->exit_state) /* already dead */ | |
694 | return 0; | |
695 | return ptrace_resume(child, request, SIGKILL); | |
696 | ||
2225a122 SS |
697 | #ifdef CONFIG_HAVE_ARCH_TRACEHOOK |
698 | case PTRACE_GETREGSET: | |
699 | case PTRACE_SETREGSET: | |
700 | { | |
701 | struct iovec kiov; | |
9fed81dc | 702 | struct iovec __user *uiov = datavp; |
2225a122 SS |
703 | |
704 | if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov))) | |
705 | return -EFAULT; | |
706 | ||
707 | if (__get_user(kiov.iov_base, &uiov->iov_base) || | |
708 | __get_user(kiov.iov_len, &uiov->iov_len)) | |
709 | return -EFAULT; | |
710 | ||
711 | ret = ptrace_regset(child, request, addr, &kiov); | |
712 | if (!ret) | |
713 | ret = __put_user(kiov.iov_len, &uiov->iov_len); | |
714 | break; | |
715 | } | |
716 | #endif | |
1da177e4 LT |
717 | default: |
718 | break; | |
719 | } | |
720 | ||
721 | return ret; | |
722 | } | |
481bed45 | 723 | |
8053bdd5 | 724 | static struct task_struct *ptrace_get_task_struct(pid_t pid) |
6b9c7ed8 CH |
725 | { |
726 | struct task_struct *child; | |
481bed45 | 727 | |
8053bdd5 | 728 | rcu_read_lock(); |
228ebcbe | 729 | child = find_task_by_vpid(pid); |
481bed45 CH |
730 | if (child) |
731 | get_task_struct(child); | |
8053bdd5 | 732 | rcu_read_unlock(); |
f400e198 | 733 | |
481bed45 | 734 | if (!child) |
6b9c7ed8 CH |
735 | return ERR_PTR(-ESRCH); |
736 | return child; | |
481bed45 CH |
737 | } |
738 | ||
0ac15559 CH |
739 | #ifndef arch_ptrace_attach |
740 | #define arch_ptrace_attach(child) do { } while (0) | |
741 | #endif | |
742 | ||
4abf9869 NK |
743 | SYSCALL_DEFINE4(ptrace, long, request, long, pid, unsigned long, addr, |
744 | unsigned long, data) | |
481bed45 CH |
745 | { |
746 | struct task_struct *child; | |
747 | long ret; | |
748 | ||
6b9c7ed8 CH |
749 | if (request == PTRACE_TRACEME) { |
750 | ret = ptrace_traceme(); | |
6ea6dd93 HS |
751 | if (!ret) |
752 | arch_ptrace_attach(current); | |
481bed45 | 753 | goto out; |
6b9c7ed8 CH |
754 | } |
755 | ||
756 | child = ptrace_get_task_struct(pid); | |
757 | if (IS_ERR(child)) { | |
758 | ret = PTR_ERR(child); | |
759 | goto out; | |
760 | } | |
481bed45 CH |
761 | |
762 | if (request == PTRACE_ATTACH) { | |
763 | ret = ptrace_attach(child); | |
0ac15559 CH |
764 | /* |
765 | * Some architectures need to do book-keeping after | |
766 | * a ptrace attach. | |
767 | */ | |
768 | if (!ret) | |
769 | arch_ptrace_attach(child); | |
005f18df | 770 | goto out_put_task_struct; |
481bed45 CH |
771 | } |
772 | ||
773 | ret = ptrace_check_attach(child, request == PTRACE_KILL); | |
774 | if (ret < 0) | |
775 | goto out_put_task_struct; | |
776 | ||
777 | ret = arch_ptrace(child, request, addr, data); | |
481bed45 CH |
778 | |
779 | out_put_task_struct: | |
780 | put_task_struct(child); | |
781 | out: | |
481bed45 CH |
782 | return ret; |
783 | } | |
76647323 | 784 | |
4abf9869 NK |
785 | int generic_ptrace_peekdata(struct task_struct *tsk, unsigned long addr, |
786 | unsigned long data) | |
76647323 AD |
787 | { |
788 | unsigned long tmp; | |
789 | int copied; | |
790 | ||
791 | copied = access_process_vm(tsk, addr, &tmp, sizeof(tmp), 0); | |
792 | if (copied != sizeof(tmp)) | |
793 | return -EIO; | |
794 | return put_user(tmp, (unsigned long __user *)data); | |
795 | } | |
f284ce72 | 796 | |
4abf9869 NK |
797 | int generic_ptrace_pokedata(struct task_struct *tsk, unsigned long addr, |
798 | unsigned long data) | |
f284ce72 AD |
799 | { |
800 | int copied; | |
801 | ||
802 | copied = access_process_vm(tsk, addr, &data, sizeof(data), 1); | |
803 | return (copied == sizeof(data)) ? 0 : -EIO; | |
804 | } | |
032d82d9 | 805 | |
96b8936a | 806 | #if defined CONFIG_COMPAT |
032d82d9 RM |
807 | #include <linux/compat.h> |
808 | ||
809 | int compat_ptrace_request(struct task_struct *child, compat_long_t request, | |
810 | compat_ulong_t addr, compat_ulong_t data) | |
811 | { | |
812 | compat_ulong_t __user *datap = compat_ptr(data); | |
813 | compat_ulong_t word; | |
e16b2781 | 814 | siginfo_t siginfo; |
032d82d9 RM |
815 | int ret; |
816 | ||
817 | switch (request) { | |
818 | case PTRACE_PEEKTEXT: | |
819 | case PTRACE_PEEKDATA: | |
820 | ret = access_process_vm(child, addr, &word, sizeof(word), 0); | |
821 | if (ret != sizeof(word)) | |
822 | ret = -EIO; | |
823 | else | |
824 | ret = put_user(word, datap); | |
825 | break; | |
826 | ||
827 | case PTRACE_POKETEXT: | |
828 | case PTRACE_POKEDATA: | |
829 | ret = access_process_vm(child, addr, &data, sizeof(data), 1); | |
830 | ret = (ret != sizeof(data) ? -EIO : 0); | |
831 | break; | |
832 | ||
833 | case PTRACE_GETEVENTMSG: | |
834 | ret = put_user((compat_ulong_t) child->ptrace_message, datap); | |
835 | break; | |
836 | ||
e16b2781 RM |
837 | case PTRACE_GETSIGINFO: |
838 | ret = ptrace_getsiginfo(child, &siginfo); | |
839 | if (!ret) | |
840 | ret = copy_siginfo_to_user32( | |
841 | (struct compat_siginfo __user *) datap, | |
842 | &siginfo); | |
843 | break; | |
844 | ||
845 | case PTRACE_SETSIGINFO: | |
846 | memset(&siginfo, 0, sizeof siginfo); | |
847 | if (copy_siginfo_from_user32( | |
848 | &siginfo, (struct compat_siginfo __user *) datap)) | |
849 | ret = -EFAULT; | |
850 | else | |
851 | ret = ptrace_setsiginfo(child, &siginfo); | |
852 | break; | |
2225a122 SS |
853 | #ifdef CONFIG_HAVE_ARCH_TRACEHOOK |
854 | case PTRACE_GETREGSET: | |
855 | case PTRACE_SETREGSET: | |
856 | { | |
857 | struct iovec kiov; | |
858 | struct compat_iovec __user *uiov = | |
859 | (struct compat_iovec __user *) datap; | |
860 | compat_uptr_t ptr; | |
861 | compat_size_t len; | |
862 | ||
863 | if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov))) | |
864 | return -EFAULT; | |
865 | ||
866 | if (__get_user(ptr, &uiov->iov_base) || | |
867 | __get_user(len, &uiov->iov_len)) | |
868 | return -EFAULT; | |
869 | ||
870 | kiov.iov_base = compat_ptr(ptr); | |
871 | kiov.iov_len = len; | |
872 | ||
873 | ret = ptrace_regset(child, request, addr, &kiov); | |
874 | if (!ret) | |
875 | ret = __put_user(kiov.iov_len, &uiov->iov_len); | |
876 | break; | |
877 | } | |
878 | #endif | |
e16b2781 | 879 | |
032d82d9 RM |
880 | default: |
881 | ret = ptrace_request(child, request, addr, data); | |
882 | } | |
883 | ||
884 | return ret; | |
885 | } | |
c269f196 | 886 | |
c269f196 RM |
887 | asmlinkage long compat_sys_ptrace(compat_long_t request, compat_long_t pid, |
888 | compat_long_t addr, compat_long_t data) | |
889 | { | |
890 | struct task_struct *child; | |
891 | long ret; | |
892 | ||
c269f196 RM |
893 | if (request == PTRACE_TRACEME) { |
894 | ret = ptrace_traceme(); | |
895 | goto out; | |
896 | } | |
897 | ||
898 | child = ptrace_get_task_struct(pid); | |
899 | if (IS_ERR(child)) { | |
900 | ret = PTR_ERR(child); | |
901 | goto out; | |
902 | } | |
903 | ||
904 | if (request == PTRACE_ATTACH) { | |
905 | ret = ptrace_attach(child); | |
906 | /* | |
907 | * Some architectures need to do book-keeping after | |
908 | * a ptrace attach. | |
909 | */ | |
910 | if (!ret) | |
911 | arch_ptrace_attach(child); | |
912 | goto out_put_task_struct; | |
913 | } | |
914 | ||
915 | ret = ptrace_check_attach(child, request == PTRACE_KILL); | |
916 | if (!ret) | |
917 | ret = compat_arch_ptrace(child, request, addr, data); | |
918 | ||
919 | out_put_task_struct: | |
920 | put_task_struct(child); | |
921 | out: | |
c269f196 RM |
922 | return ret; |
923 | } | |
96b8936a | 924 | #endif /* CONFIG_COMPAT */ |
bf26c018 FW |
925 | |
926 | #ifdef CONFIG_HAVE_HW_BREAKPOINT | |
927 | int ptrace_get_breakpoints(struct task_struct *tsk) | |
928 | { | |
929 | if (atomic_inc_not_zero(&tsk->ptrace_bp_refcnt)) | |
930 | return 0; | |
931 | ||
932 | return -1; | |
933 | } | |
934 | ||
935 | void ptrace_put_breakpoints(struct task_struct *tsk) | |
936 | { | |
937 | if (atomic_dec_and_test(&tsk->ptrace_bp_refcnt)) | |
938 | flush_ptrace_hw_breakpoint(tsk); | |
939 | } | |
940 | #endif /* CONFIG_HAVE_HW_BREAKPOINT */ |