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 | |
1da177e4 LT |
41 | /* |
42 | * Turn a tracing stop into a normal stop now, since with no tracer there | |
43 | * would be no way to wake it up with SIGCONT or SIGKILL. If there was a | |
44 | * signal sent that would resume the child, but didn't because it was in | |
45 | * TASK_TRACED, resume it now. | |
46 | * Requires that irqs be disabled. | |
47 | */ | |
b747c8c1 | 48 | static void ptrace_untrace(struct task_struct *child) |
1da177e4 LT |
49 | { |
50 | spin_lock(&child->sighand->siglock); | |
6618a3e2 | 51 | if (task_is_traced(child)) { |
1ee11844 ON |
52 | /* |
53 | * If the group stop is completed or in progress, | |
54 | * this thread was already counted as stopped. | |
55 | */ | |
56 | if (child->signal->flags & SIGNAL_STOP_STOPPED || | |
57 | child->signal->group_stop_count) | |
d9ae90ac | 58 | __set_task_state(child, TASK_STOPPED); |
1ee11844 | 59 | else |
1da177e4 | 60 | signal_wake_up(child, 1); |
1da177e4 LT |
61 | } |
62 | spin_unlock(&child->sighand->siglock); | |
63 | } | |
64 | ||
65 | /* | |
66 | * unptrace a task: move it back to its original parent and | |
67 | * remove it from the ptrace list. | |
68 | * | |
69 | * Must be called with the tasklist lock write-held. | |
70 | */ | |
36c8b586 | 71 | void __ptrace_unlink(struct task_struct *child) |
1da177e4 | 72 | { |
5ecfbae0 ON |
73 | BUG_ON(!child->ptrace); |
74 | ||
1da177e4 | 75 | child->ptrace = 0; |
f470021a RM |
76 | child->parent = child->real_parent; |
77 | list_del_init(&child->ptrace_entry); | |
1da177e4 | 78 | |
6618a3e2 | 79 | if (task_is_traced(child)) |
e57a5059 | 80 | ptrace_untrace(child); |
1da177e4 LT |
81 | } |
82 | ||
83 | /* | |
84 | * Check that we have indeed attached to the thing.. | |
85 | */ | |
86 | int ptrace_check_attach(struct task_struct *child, int kill) | |
87 | { | |
88 | int ret = -ESRCH; | |
89 | ||
90 | /* | |
91 | * We take the read lock around doing both checks to close a | |
92 | * possible race where someone else was tracing our child and | |
93 | * detached between these two checks. After this locked check, | |
94 | * we are sure that this is our traced child and that can only | |
95 | * be changed by us so it's not changing right after this. | |
96 | */ | |
97 | read_lock(&tasklist_lock); | |
c0c0b649 | 98 | if ((child->ptrace & PT_PTRACED) && child->parent == current) { |
1da177e4 | 99 | ret = 0; |
c0c0b649 ON |
100 | /* |
101 | * child->sighand can't be NULL, release_task() | |
102 | * does ptrace_unlink() before __exit_signal(). | |
103 | */ | |
1da177e4 | 104 | spin_lock_irq(&child->sighand->siglock); |
d9ae90ac | 105 | if (task_is_stopped(child)) |
1da177e4 | 106 | child->state = TASK_TRACED; |
d9ae90ac | 107 | else if (!task_is_traced(child) && !kill) |
1da177e4 | 108 | ret = -ESRCH; |
1da177e4 LT |
109 | spin_unlock_irq(&child->sighand->siglock); |
110 | } | |
111 | read_unlock(&tasklist_lock); | |
112 | ||
d9ae90ac | 113 | if (!ret && !kill) |
85ba2d86 | 114 | ret = wait_task_inactive(child, TASK_TRACED) ? 0 : -ESRCH; |
1da177e4 LT |
115 | |
116 | /* All systems go.. */ | |
117 | return ret; | |
118 | } | |
119 | ||
006ebb40 | 120 | int __ptrace_may_access(struct task_struct *task, unsigned int mode) |
ab8d11be | 121 | { |
c69e8d9c | 122 | const struct cred *cred = current_cred(), *tcred; |
b6dff3ec | 123 | |
df26c40e EB |
124 | /* May we inspect the given task? |
125 | * This check is used both for attaching with ptrace | |
126 | * and for allowing access to sensitive information in /proc. | |
127 | * | |
128 | * ptrace_attach denies several cases that /proc allows | |
129 | * because setting up the necessary parent/child relationship | |
130 | * or halting the specified task is impossible. | |
131 | */ | |
132 | int dumpable = 0; | |
133 | /* Don't let security modules deny introspection */ | |
134 | if (task == current) | |
135 | return 0; | |
c69e8d9c DH |
136 | rcu_read_lock(); |
137 | tcred = __task_cred(task); | |
8409cca7 SH |
138 | if (cred->user->user_ns == tcred->user->user_ns && |
139 | (cred->uid == tcred->euid && | |
140 | cred->uid == tcred->suid && | |
141 | cred->uid == tcred->uid && | |
142 | cred->gid == tcred->egid && | |
143 | cred->gid == tcred->sgid && | |
144 | cred->gid == tcred->gid)) | |
145 | goto ok; | |
146 | if (ns_capable(tcred->user->user_ns, CAP_SYS_PTRACE)) | |
147 | goto ok; | |
148 | rcu_read_unlock(); | |
149 | return -EPERM; | |
150 | ok: | |
c69e8d9c | 151 | rcu_read_unlock(); |
ab8d11be | 152 | smp_rmb(); |
df26c40e | 153 | if (task->mm) |
6c5d5238 | 154 | dumpable = get_dumpable(task->mm); |
8409cca7 | 155 | if (!dumpable && !task_ns_capable(task, CAP_SYS_PTRACE)) |
ab8d11be MS |
156 | return -EPERM; |
157 | ||
9e48858f | 158 | return security_ptrace_access_check(task, mode); |
ab8d11be MS |
159 | } |
160 | ||
006ebb40 | 161 | bool ptrace_may_access(struct task_struct *task, unsigned int mode) |
ab8d11be MS |
162 | { |
163 | int err; | |
164 | task_lock(task); | |
006ebb40 | 165 | err = __ptrace_may_access(task, mode); |
ab8d11be | 166 | task_unlock(task); |
3a709703 | 167 | return !err; |
ab8d11be MS |
168 | } |
169 | ||
e3e89cc5 | 170 | static int ptrace_attach(struct task_struct *task) |
1da177e4 LT |
171 | { |
172 | int retval; | |
f5b40e36 | 173 | |
a5cb013d AV |
174 | audit_ptrace(task); |
175 | ||
1da177e4 | 176 | retval = -EPERM; |
b79b7ba9 ON |
177 | if (unlikely(task->flags & PF_KTHREAD)) |
178 | goto out; | |
bac0abd6 | 179 | if (same_thread_group(task, current)) |
f5b40e36 LT |
180 | goto out; |
181 | ||
f2f0b00a ON |
182 | /* |
183 | * Protect exec's credential calculations against our interference; | |
5e751e99 DH |
184 | * interference; SUID, SGID and LSM creds get determined differently |
185 | * under ptrace. | |
d84f4f99 | 186 | */ |
793285fc | 187 | retval = -ERESTARTNOINTR; |
9b1bf12d | 188 | if (mutex_lock_interruptible(&task->signal->cred_guard_mutex)) |
d84f4f99 | 189 | goto out; |
f5b40e36 | 190 | |
4b105cbb | 191 | task_lock(task); |
006ebb40 | 192 | retval = __ptrace_may_access(task, PTRACE_MODE_ATTACH); |
4b105cbb | 193 | task_unlock(task); |
1da177e4 | 194 | if (retval) |
4b105cbb | 195 | goto unlock_creds; |
1da177e4 | 196 | |
4b105cbb | 197 | write_lock_irq(&tasklist_lock); |
b79b7ba9 ON |
198 | retval = -EPERM; |
199 | if (unlikely(task->exit_state)) | |
4b105cbb | 200 | goto unlock_tasklist; |
f2f0b00a | 201 | if (task->ptrace) |
4b105cbb | 202 | goto unlock_tasklist; |
b79b7ba9 | 203 | |
f2f0b00a | 204 | task->ptrace = PT_PTRACED; |
8409cca7 | 205 | if (task_ns_capable(task, CAP_SYS_PTRACE)) |
1da177e4 | 206 | task->ptrace |= PT_PTRACE_CAP; |
1da177e4 | 207 | |
1da177e4 | 208 | __ptrace_link(task, current); |
33e9fc7d | 209 | send_sig_info(SIGSTOP, SEND_SIG_FORCED, task); |
b79b7ba9 ON |
210 | |
211 | retval = 0; | |
4b105cbb ON |
212 | unlock_tasklist: |
213 | write_unlock_irq(&tasklist_lock); | |
214 | unlock_creds: | |
9b1bf12d | 215 | mutex_unlock(&task->signal->cred_guard_mutex); |
f5b40e36 | 216 | out: |
1da177e4 LT |
217 | return retval; |
218 | } | |
219 | ||
f2f0b00a ON |
220 | /** |
221 | * ptrace_traceme -- helper for PTRACE_TRACEME | |
222 | * | |
223 | * Performs checks and sets PT_PTRACED. | |
224 | * Should be used by all ptrace implementations for PTRACE_TRACEME. | |
225 | */ | |
e3e89cc5 | 226 | static int ptrace_traceme(void) |
f2f0b00a ON |
227 | { |
228 | int ret = -EPERM; | |
229 | ||
4b105cbb ON |
230 | write_lock_irq(&tasklist_lock); |
231 | /* Are we already being traced? */ | |
f2f0b00a | 232 | if (!current->ptrace) { |
f2f0b00a | 233 | ret = security_ptrace_traceme(current->parent); |
f2f0b00a ON |
234 | /* |
235 | * Check PF_EXITING to ensure ->real_parent has not passed | |
236 | * exit_ptrace(). Otherwise we don't report the error but | |
237 | * pretend ->real_parent untraces us right after return. | |
238 | */ | |
239 | if (!ret && !(current->real_parent->flags & PF_EXITING)) { | |
240 | current->ptrace = PT_PTRACED; | |
241 | __ptrace_link(current, current->real_parent); | |
242 | } | |
f2f0b00a | 243 | } |
4b105cbb ON |
244 | write_unlock_irq(&tasklist_lock); |
245 | ||
f2f0b00a ON |
246 | return ret; |
247 | } | |
248 | ||
39c626ae ON |
249 | /* |
250 | * Called with irqs disabled, returns true if childs should reap themselves. | |
251 | */ | |
252 | static int ignoring_children(struct sighand_struct *sigh) | |
253 | { | |
254 | int ret; | |
255 | spin_lock(&sigh->siglock); | |
256 | ret = (sigh->action[SIGCHLD-1].sa.sa_handler == SIG_IGN) || | |
257 | (sigh->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT); | |
258 | spin_unlock(&sigh->siglock); | |
259 | return ret; | |
260 | } | |
261 | ||
262 | /* | |
263 | * Called with tasklist_lock held for writing. | |
264 | * Unlink a traced task, and clean it up if it was a traced zombie. | |
265 | * Return true if it needs to be reaped with release_task(). | |
266 | * (We can't call release_task() here because we already hold tasklist_lock.) | |
267 | * | |
268 | * If it's a zombie, our attachedness prevented normal parent notification | |
269 | * or self-reaping. Do notification now if it would have happened earlier. | |
270 | * If it should reap itself, return true. | |
271 | * | |
a7f0765e ON |
272 | * If it's our own child, there is no notification to do. But if our normal |
273 | * children self-reap, then this child was prevented by ptrace and we must | |
274 | * reap it now, in that case we must also wake up sub-threads sleeping in | |
275 | * do_wait(). | |
39c626ae ON |
276 | */ |
277 | static bool __ptrace_detach(struct task_struct *tracer, struct task_struct *p) | |
278 | { | |
279 | __ptrace_unlink(p); | |
280 | ||
281 | if (p->exit_state == EXIT_ZOMBIE) { | |
282 | if (!task_detached(p) && thread_group_empty(p)) { | |
283 | if (!same_thread_group(p->real_parent, tracer)) | |
284 | do_notify_parent(p, p->exit_signal); | |
a7f0765e ON |
285 | else if (ignoring_children(tracer->sighand)) { |
286 | __wake_up_parent(p, tracer); | |
39c626ae | 287 | p->exit_signal = -1; |
a7f0765e | 288 | } |
39c626ae ON |
289 | } |
290 | if (task_detached(p)) { | |
291 | /* Mark it as in the process of being reaped. */ | |
292 | p->exit_state = EXIT_DEAD; | |
293 | return true; | |
294 | } | |
295 | } | |
296 | ||
297 | return false; | |
298 | } | |
299 | ||
e3e89cc5 | 300 | static int ptrace_detach(struct task_struct *child, unsigned int data) |
1da177e4 | 301 | { |
39c626ae | 302 | bool dead = false; |
4576145c | 303 | |
7ed20e1a | 304 | if (!valid_signal(data)) |
5ecfbae0 | 305 | return -EIO; |
1da177e4 LT |
306 | |
307 | /* Architecture-specific hardware disable .. */ | |
308 | ptrace_disable(child); | |
7d941432 | 309 | clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); |
1da177e4 | 310 | |
95c3eb76 | 311 | write_lock_irq(&tasklist_lock); |
39c626ae ON |
312 | /* |
313 | * This child can be already killed. Make sure de_thread() or | |
314 | * our sub-thread doing do_wait() didn't do release_task() yet. | |
315 | */ | |
95c3eb76 ON |
316 | if (child->ptrace) { |
317 | child->exit_code = data; | |
4576145c | 318 | dead = __ptrace_detach(current, child); |
edaba2c5 | 319 | if (!child->exit_state) |
01e05e9a | 320 | wake_up_state(child, TASK_TRACED | TASK_STOPPED); |
95c3eb76 | 321 | } |
1da177e4 LT |
322 | write_unlock_irq(&tasklist_lock); |
323 | ||
4576145c ON |
324 | if (unlikely(dead)) |
325 | release_task(child); | |
326 | ||
1da177e4 LT |
327 | return 0; |
328 | } | |
329 | ||
39c626ae | 330 | /* |
c7e49c14 ON |
331 | * Detach all tasks we were using ptrace on. Called with tasklist held |
332 | * for writing, and returns with it held too. But note it can release | |
333 | * and reacquire the lock. | |
39c626ae ON |
334 | */ |
335 | void exit_ptrace(struct task_struct *tracer) | |
c4b5ed25 NK |
336 | __releases(&tasklist_lock) |
337 | __acquires(&tasklist_lock) | |
39c626ae ON |
338 | { |
339 | struct task_struct *p, *n; | |
340 | LIST_HEAD(ptrace_dead); | |
341 | ||
c7e49c14 ON |
342 | if (likely(list_empty(&tracer->ptraced))) |
343 | return; | |
344 | ||
39c626ae ON |
345 | list_for_each_entry_safe(p, n, &tracer->ptraced, ptrace_entry) { |
346 | if (__ptrace_detach(tracer, p)) | |
347 | list_add(&p->ptrace_entry, &ptrace_dead); | |
348 | } | |
39c626ae | 349 | |
c7e49c14 | 350 | write_unlock_irq(&tasklist_lock); |
39c626ae ON |
351 | BUG_ON(!list_empty(&tracer->ptraced)); |
352 | ||
353 | list_for_each_entry_safe(p, n, &ptrace_dead, ptrace_entry) { | |
354 | list_del_init(&p->ptrace_entry); | |
355 | release_task(p); | |
356 | } | |
c7e49c14 ON |
357 | |
358 | write_lock_irq(&tasklist_lock); | |
39c626ae ON |
359 | } |
360 | ||
1da177e4 LT |
361 | int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len) |
362 | { | |
363 | int copied = 0; | |
364 | ||
365 | while (len > 0) { | |
366 | char buf[128]; | |
367 | int this_len, retval; | |
368 | ||
369 | this_len = (len > sizeof(buf)) ? sizeof(buf) : len; | |
370 | retval = access_process_vm(tsk, src, buf, this_len, 0); | |
371 | if (!retval) { | |
372 | if (copied) | |
373 | break; | |
374 | return -EIO; | |
375 | } | |
376 | if (copy_to_user(dst, buf, retval)) | |
377 | return -EFAULT; | |
378 | copied += retval; | |
379 | src += retval; | |
380 | dst += retval; | |
3a709703 | 381 | len -= retval; |
1da177e4 LT |
382 | } |
383 | return copied; | |
384 | } | |
385 | ||
386 | int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len) | |
387 | { | |
388 | int copied = 0; | |
389 | ||
390 | while (len > 0) { | |
391 | char buf[128]; | |
392 | int this_len, retval; | |
393 | ||
394 | this_len = (len > sizeof(buf)) ? sizeof(buf) : len; | |
395 | if (copy_from_user(buf, src, this_len)) | |
396 | return -EFAULT; | |
397 | retval = access_process_vm(tsk, dst, buf, this_len, 1); | |
398 | if (!retval) { | |
399 | if (copied) | |
400 | break; | |
401 | return -EIO; | |
402 | } | |
403 | copied += retval; | |
404 | src += retval; | |
405 | dst += retval; | |
3a709703 | 406 | len -= retval; |
1da177e4 LT |
407 | } |
408 | return copied; | |
409 | } | |
410 | ||
4abf9869 | 411 | static int ptrace_setoptions(struct task_struct *child, unsigned long data) |
1da177e4 LT |
412 | { |
413 | child->ptrace &= ~PT_TRACE_MASK; | |
414 | ||
415 | if (data & PTRACE_O_TRACESYSGOOD) | |
416 | child->ptrace |= PT_TRACESYSGOOD; | |
417 | ||
418 | if (data & PTRACE_O_TRACEFORK) | |
419 | child->ptrace |= PT_TRACE_FORK; | |
420 | ||
421 | if (data & PTRACE_O_TRACEVFORK) | |
422 | child->ptrace |= PT_TRACE_VFORK; | |
423 | ||
424 | if (data & PTRACE_O_TRACECLONE) | |
425 | child->ptrace |= PT_TRACE_CLONE; | |
426 | ||
427 | if (data & PTRACE_O_TRACEEXEC) | |
428 | child->ptrace |= PT_TRACE_EXEC; | |
429 | ||
430 | if (data & PTRACE_O_TRACEVFORKDONE) | |
431 | child->ptrace |= PT_TRACE_VFORK_DONE; | |
432 | ||
433 | if (data & PTRACE_O_TRACEEXIT) | |
434 | child->ptrace |= PT_TRACE_EXIT; | |
435 | ||
436 | return (data & ~PTRACE_O_MASK) ? -EINVAL : 0; | |
437 | } | |
438 | ||
e16b2781 | 439 | static int ptrace_getsiginfo(struct task_struct *child, siginfo_t *info) |
1da177e4 | 440 | { |
e4961254 | 441 | unsigned long flags; |
1da177e4 LT |
442 | int error = -ESRCH; |
443 | ||
e4961254 | 444 | if (lock_task_sighand(child, &flags)) { |
1da177e4 | 445 | error = -EINVAL; |
1da177e4 | 446 | if (likely(child->last_siginfo != NULL)) { |
e16b2781 | 447 | *info = *child->last_siginfo; |
1da177e4 LT |
448 | error = 0; |
449 | } | |
e4961254 | 450 | unlock_task_sighand(child, &flags); |
1da177e4 | 451 | } |
1da177e4 LT |
452 | return error; |
453 | } | |
454 | ||
e16b2781 | 455 | static int ptrace_setsiginfo(struct task_struct *child, const siginfo_t *info) |
1da177e4 | 456 | { |
e4961254 | 457 | unsigned long flags; |
1da177e4 LT |
458 | int error = -ESRCH; |
459 | ||
e4961254 | 460 | if (lock_task_sighand(child, &flags)) { |
1da177e4 | 461 | error = -EINVAL; |
1da177e4 | 462 | if (likely(child->last_siginfo != NULL)) { |
e16b2781 | 463 | *child->last_siginfo = *info; |
1da177e4 LT |
464 | error = 0; |
465 | } | |
e4961254 | 466 | unlock_task_sighand(child, &flags); |
1da177e4 | 467 | } |
1da177e4 LT |
468 | return error; |
469 | } | |
470 | ||
36df29d7 RM |
471 | |
472 | #ifdef PTRACE_SINGLESTEP | |
473 | #define is_singlestep(request) ((request) == PTRACE_SINGLESTEP) | |
474 | #else | |
475 | #define is_singlestep(request) 0 | |
476 | #endif | |
477 | ||
5b88abbf RM |
478 | #ifdef PTRACE_SINGLEBLOCK |
479 | #define is_singleblock(request) ((request) == PTRACE_SINGLEBLOCK) | |
480 | #else | |
481 | #define is_singleblock(request) 0 | |
482 | #endif | |
483 | ||
36df29d7 RM |
484 | #ifdef PTRACE_SYSEMU |
485 | #define is_sysemu_singlestep(request) ((request) == PTRACE_SYSEMU_SINGLESTEP) | |
486 | #else | |
487 | #define is_sysemu_singlestep(request) 0 | |
488 | #endif | |
489 | ||
4abf9869 NK |
490 | static int ptrace_resume(struct task_struct *child, long request, |
491 | unsigned long data) | |
36df29d7 RM |
492 | { |
493 | if (!valid_signal(data)) | |
494 | return -EIO; | |
495 | ||
496 | if (request == PTRACE_SYSCALL) | |
497 | set_tsk_thread_flag(child, TIF_SYSCALL_TRACE); | |
498 | else | |
499 | clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); | |
500 | ||
501 | #ifdef TIF_SYSCALL_EMU | |
502 | if (request == PTRACE_SYSEMU || request == PTRACE_SYSEMU_SINGLESTEP) | |
503 | set_tsk_thread_flag(child, TIF_SYSCALL_EMU); | |
504 | else | |
505 | clear_tsk_thread_flag(child, TIF_SYSCALL_EMU); | |
506 | #endif | |
507 | ||
5b88abbf RM |
508 | if (is_singleblock(request)) { |
509 | if (unlikely(!arch_has_block_step())) | |
510 | return -EIO; | |
511 | user_enable_block_step(child); | |
512 | } else if (is_singlestep(request) || is_sysemu_singlestep(request)) { | |
36df29d7 RM |
513 | if (unlikely(!arch_has_single_step())) |
514 | return -EIO; | |
515 | user_enable_single_step(child); | |
3a709703 | 516 | } else { |
36df29d7 | 517 | user_disable_single_step(child); |
3a709703 | 518 | } |
36df29d7 RM |
519 | |
520 | child->exit_code = data; | |
521 | wake_up_process(child); | |
522 | ||
523 | return 0; | |
524 | } | |
525 | ||
2225a122 SS |
526 | #ifdef CONFIG_HAVE_ARCH_TRACEHOOK |
527 | ||
528 | static const struct user_regset * | |
529 | find_regset(const struct user_regset_view *view, unsigned int type) | |
530 | { | |
531 | const struct user_regset *regset; | |
532 | int n; | |
533 | ||
534 | for (n = 0; n < view->n; ++n) { | |
535 | regset = view->regsets + n; | |
536 | if (regset->core_note_type == type) | |
537 | return regset; | |
538 | } | |
539 | ||
540 | return NULL; | |
541 | } | |
542 | ||
543 | static int ptrace_regset(struct task_struct *task, int req, unsigned int type, | |
544 | struct iovec *kiov) | |
545 | { | |
546 | const struct user_regset_view *view = task_user_regset_view(task); | |
547 | const struct user_regset *regset = find_regset(view, type); | |
548 | int regset_no; | |
549 | ||
550 | if (!regset || (kiov->iov_len % regset->size) != 0) | |
c6a0dd7e | 551 | return -EINVAL; |
2225a122 SS |
552 | |
553 | regset_no = regset - view->regsets; | |
554 | kiov->iov_len = min(kiov->iov_len, | |
555 | (__kernel_size_t) (regset->n * regset->size)); | |
556 | ||
557 | if (req == PTRACE_GETREGSET) | |
558 | return copy_regset_to_user(task, view, regset_no, 0, | |
559 | kiov->iov_len, kiov->iov_base); | |
560 | else | |
561 | return copy_regset_from_user(task, view, regset_no, 0, | |
562 | kiov->iov_len, kiov->iov_base); | |
563 | } | |
564 | ||
565 | #endif | |
566 | ||
1da177e4 | 567 | int ptrace_request(struct task_struct *child, long request, |
4abf9869 | 568 | unsigned long addr, unsigned long data) |
1da177e4 LT |
569 | { |
570 | int ret = -EIO; | |
e16b2781 | 571 | siginfo_t siginfo; |
9fed81dc NK |
572 | void __user *datavp = (void __user *) data; |
573 | unsigned long __user *datalp = datavp; | |
1da177e4 LT |
574 | |
575 | switch (request) { | |
16c3e389 RM |
576 | case PTRACE_PEEKTEXT: |
577 | case PTRACE_PEEKDATA: | |
578 | return generic_ptrace_peekdata(child, addr, data); | |
579 | case PTRACE_POKETEXT: | |
580 | case PTRACE_POKEDATA: | |
581 | return generic_ptrace_pokedata(child, addr, data); | |
582 | ||
1da177e4 LT |
583 | #ifdef PTRACE_OLDSETOPTIONS |
584 | case PTRACE_OLDSETOPTIONS: | |
585 | #endif | |
586 | case PTRACE_SETOPTIONS: | |
587 | ret = ptrace_setoptions(child, data); | |
588 | break; | |
589 | case PTRACE_GETEVENTMSG: | |
9fed81dc | 590 | ret = put_user(child->ptrace_message, datalp); |
1da177e4 | 591 | break; |
e16b2781 | 592 | |
1da177e4 | 593 | case PTRACE_GETSIGINFO: |
e16b2781 RM |
594 | ret = ptrace_getsiginfo(child, &siginfo); |
595 | if (!ret) | |
9fed81dc | 596 | ret = copy_siginfo_to_user(datavp, &siginfo); |
1da177e4 | 597 | break; |
e16b2781 | 598 | |
1da177e4 | 599 | case PTRACE_SETSIGINFO: |
9fed81dc | 600 | if (copy_from_user(&siginfo, datavp, sizeof siginfo)) |
e16b2781 RM |
601 | ret = -EFAULT; |
602 | else | |
603 | ret = ptrace_setsiginfo(child, &siginfo); | |
1da177e4 | 604 | break; |
e16b2781 | 605 | |
1bcf5482 AD |
606 | case PTRACE_DETACH: /* detach a process that was attached. */ |
607 | ret = ptrace_detach(child, data); | |
608 | break; | |
36df29d7 | 609 | |
9c1a1259 MF |
610 | #ifdef CONFIG_BINFMT_ELF_FDPIC |
611 | case PTRACE_GETFDPIC: { | |
e0129ef9 | 612 | struct mm_struct *mm = get_task_mm(child); |
9c1a1259 MF |
613 | unsigned long tmp = 0; |
614 | ||
e0129ef9 ON |
615 | ret = -ESRCH; |
616 | if (!mm) | |
617 | break; | |
618 | ||
9c1a1259 MF |
619 | switch (addr) { |
620 | case PTRACE_GETFDPIC_EXEC: | |
e0129ef9 | 621 | tmp = mm->context.exec_fdpic_loadmap; |
9c1a1259 MF |
622 | break; |
623 | case PTRACE_GETFDPIC_INTERP: | |
e0129ef9 | 624 | tmp = mm->context.interp_fdpic_loadmap; |
9c1a1259 MF |
625 | break; |
626 | default: | |
627 | break; | |
628 | } | |
e0129ef9 | 629 | mmput(mm); |
9c1a1259 | 630 | |
9fed81dc | 631 | ret = put_user(tmp, datalp); |
9c1a1259 MF |
632 | break; |
633 | } | |
634 | #endif | |
635 | ||
36df29d7 RM |
636 | #ifdef PTRACE_SINGLESTEP |
637 | case PTRACE_SINGLESTEP: | |
638 | #endif | |
5b88abbf RM |
639 | #ifdef PTRACE_SINGLEBLOCK |
640 | case PTRACE_SINGLEBLOCK: | |
641 | #endif | |
36df29d7 RM |
642 | #ifdef PTRACE_SYSEMU |
643 | case PTRACE_SYSEMU: | |
644 | case PTRACE_SYSEMU_SINGLESTEP: | |
645 | #endif | |
646 | case PTRACE_SYSCALL: | |
647 | case PTRACE_CONT: | |
648 | return ptrace_resume(child, request, data); | |
649 | ||
650 | case PTRACE_KILL: | |
651 | if (child->exit_state) /* already dead */ | |
652 | return 0; | |
653 | return ptrace_resume(child, request, SIGKILL); | |
654 | ||
2225a122 SS |
655 | #ifdef CONFIG_HAVE_ARCH_TRACEHOOK |
656 | case PTRACE_GETREGSET: | |
657 | case PTRACE_SETREGSET: | |
658 | { | |
659 | struct iovec kiov; | |
9fed81dc | 660 | struct iovec __user *uiov = datavp; |
2225a122 SS |
661 | |
662 | if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov))) | |
663 | return -EFAULT; | |
664 | ||
665 | if (__get_user(kiov.iov_base, &uiov->iov_base) || | |
666 | __get_user(kiov.iov_len, &uiov->iov_len)) | |
667 | return -EFAULT; | |
668 | ||
669 | ret = ptrace_regset(child, request, addr, &kiov); | |
670 | if (!ret) | |
671 | ret = __put_user(kiov.iov_len, &uiov->iov_len); | |
672 | break; | |
673 | } | |
674 | #endif | |
1da177e4 LT |
675 | default: |
676 | break; | |
677 | } | |
678 | ||
679 | return ret; | |
680 | } | |
481bed45 | 681 | |
8053bdd5 | 682 | static struct task_struct *ptrace_get_task_struct(pid_t pid) |
6b9c7ed8 CH |
683 | { |
684 | struct task_struct *child; | |
481bed45 | 685 | |
8053bdd5 | 686 | rcu_read_lock(); |
228ebcbe | 687 | child = find_task_by_vpid(pid); |
481bed45 CH |
688 | if (child) |
689 | get_task_struct(child); | |
8053bdd5 | 690 | rcu_read_unlock(); |
f400e198 | 691 | |
481bed45 | 692 | if (!child) |
6b9c7ed8 CH |
693 | return ERR_PTR(-ESRCH); |
694 | return child; | |
481bed45 CH |
695 | } |
696 | ||
0ac15559 CH |
697 | #ifndef arch_ptrace_attach |
698 | #define arch_ptrace_attach(child) do { } while (0) | |
699 | #endif | |
700 | ||
4abf9869 NK |
701 | SYSCALL_DEFINE4(ptrace, long, request, long, pid, unsigned long, addr, |
702 | unsigned long, data) | |
481bed45 CH |
703 | { |
704 | struct task_struct *child; | |
705 | long ret; | |
706 | ||
6b9c7ed8 CH |
707 | if (request == PTRACE_TRACEME) { |
708 | ret = ptrace_traceme(); | |
6ea6dd93 HS |
709 | if (!ret) |
710 | arch_ptrace_attach(current); | |
481bed45 | 711 | goto out; |
6b9c7ed8 CH |
712 | } |
713 | ||
714 | child = ptrace_get_task_struct(pid); | |
715 | if (IS_ERR(child)) { | |
716 | ret = PTR_ERR(child); | |
717 | goto out; | |
718 | } | |
481bed45 CH |
719 | |
720 | if (request == PTRACE_ATTACH) { | |
721 | ret = ptrace_attach(child); | |
0ac15559 CH |
722 | /* |
723 | * Some architectures need to do book-keeping after | |
724 | * a ptrace attach. | |
725 | */ | |
726 | if (!ret) | |
727 | arch_ptrace_attach(child); | |
005f18df | 728 | goto out_put_task_struct; |
481bed45 CH |
729 | } |
730 | ||
731 | ret = ptrace_check_attach(child, request == PTRACE_KILL); | |
732 | if (ret < 0) | |
733 | goto out_put_task_struct; | |
734 | ||
735 | ret = arch_ptrace(child, request, addr, data); | |
481bed45 CH |
736 | |
737 | out_put_task_struct: | |
738 | put_task_struct(child); | |
739 | out: | |
481bed45 CH |
740 | return ret; |
741 | } | |
76647323 | 742 | |
4abf9869 NK |
743 | int generic_ptrace_peekdata(struct task_struct *tsk, unsigned long addr, |
744 | unsigned long data) | |
76647323 AD |
745 | { |
746 | unsigned long tmp; | |
747 | int copied; | |
748 | ||
749 | copied = access_process_vm(tsk, addr, &tmp, sizeof(tmp), 0); | |
750 | if (copied != sizeof(tmp)) | |
751 | return -EIO; | |
752 | return put_user(tmp, (unsigned long __user *)data); | |
753 | } | |
f284ce72 | 754 | |
4abf9869 NK |
755 | int generic_ptrace_pokedata(struct task_struct *tsk, unsigned long addr, |
756 | unsigned long data) | |
f284ce72 AD |
757 | { |
758 | int copied; | |
759 | ||
760 | copied = access_process_vm(tsk, addr, &data, sizeof(data), 1); | |
761 | return (copied == sizeof(data)) ? 0 : -EIO; | |
762 | } | |
032d82d9 | 763 | |
96b8936a | 764 | #if defined CONFIG_COMPAT |
032d82d9 RM |
765 | #include <linux/compat.h> |
766 | ||
767 | int compat_ptrace_request(struct task_struct *child, compat_long_t request, | |
768 | compat_ulong_t addr, compat_ulong_t data) | |
769 | { | |
770 | compat_ulong_t __user *datap = compat_ptr(data); | |
771 | compat_ulong_t word; | |
e16b2781 | 772 | siginfo_t siginfo; |
032d82d9 RM |
773 | int ret; |
774 | ||
775 | switch (request) { | |
776 | case PTRACE_PEEKTEXT: | |
777 | case PTRACE_PEEKDATA: | |
778 | ret = access_process_vm(child, addr, &word, sizeof(word), 0); | |
779 | if (ret != sizeof(word)) | |
780 | ret = -EIO; | |
781 | else | |
782 | ret = put_user(word, datap); | |
783 | break; | |
784 | ||
785 | case PTRACE_POKETEXT: | |
786 | case PTRACE_POKEDATA: | |
787 | ret = access_process_vm(child, addr, &data, sizeof(data), 1); | |
788 | ret = (ret != sizeof(data) ? -EIO : 0); | |
789 | break; | |
790 | ||
791 | case PTRACE_GETEVENTMSG: | |
792 | ret = put_user((compat_ulong_t) child->ptrace_message, datap); | |
793 | break; | |
794 | ||
e16b2781 RM |
795 | case PTRACE_GETSIGINFO: |
796 | ret = ptrace_getsiginfo(child, &siginfo); | |
797 | if (!ret) | |
798 | ret = copy_siginfo_to_user32( | |
799 | (struct compat_siginfo __user *) datap, | |
800 | &siginfo); | |
801 | break; | |
802 | ||
803 | case PTRACE_SETSIGINFO: | |
804 | memset(&siginfo, 0, sizeof siginfo); | |
805 | if (copy_siginfo_from_user32( | |
806 | &siginfo, (struct compat_siginfo __user *) datap)) | |
807 | ret = -EFAULT; | |
808 | else | |
809 | ret = ptrace_setsiginfo(child, &siginfo); | |
810 | break; | |
2225a122 SS |
811 | #ifdef CONFIG_HAVE_ARCH_TRACEHOOK |
812 | case PTRACE_GETREGSET: | |
813 | case PTRACE_SETREGSET: | |
814 | { | |
815 | struct iovec kiov; | |
816 | struct compat_iovec __user *uiov = | |
817 | (struct compat_iovec __user *) datap; | |
818 | compat_uptr_t ptr; | |
819 | compat_size_t len; | |
820 | ||
821 | if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov))) | |
822 | return -EFAULT; | |
823 | ||
824 | if (__get_user(ptr, &uiov->iov_base) || | |
825 | __get_user(len, &uiov->iov_len)) | |
826 | return -EFAULT; | |
827 | ||
828 | kiov.iov_base = compat_ptr(ptr); | |
829 | kiov.iov_len = len; | |
830 | ||
831 | ret = ptrace_regset(child, request, addr, &kiov); | |
832 | if (!ret) | |
833 | ret = __put_user(kiov.iov_len, &uiov->iov_len); | |
834 | break; | |
835 | } | |
836 | #endif | |
e16b2781 | 837 | |
032d82d9 RM |
838 | default: |
839 | ret = ptrace_request(child, request, addr, data); | |
840 | } | |
841 | ||
842 | return ret; | |
843 | } | |
c269f196 | 844 | |
c269f196 RM |
845 | asmlinkage long compat_sys_ptrace(compat_long_t request, compat_long_t pid, |
846 | compat_long_t addr, compat_long_t data) | |
847 | { | |
848 | struct task_struct *child; | |
849 | long ret; | |
850 | ||
c269f196 RM |
851 | if (request == PTRACE_TRACEME) { |
852 | ret = ptrace_traceme(); | |
853 | goto out; | |
854 | } | |
855 | ||
856 | child = ptrace_get_task_struct(pid); | |
857 | if (IS_ERR(child)) { | |
858 | ret = PTR_ERR(child); | |
859 | goto out; | |
860 | } | |
861 | ||
862 | if (request == PTRACE_ATTACH) { | |
863 | ret = ptrace_attach(child); | |
864 | /* | |
865 | * Some architectures need to do book-keeping after | |
866 | * a ptrace attach. | |
867 | */ | |
868 | if (!ret) | |
869 | arch_ptrace_attach(child); | |
870 | goto out_put_task_struct; | |
871 | } | |
872 | ||
873 | ret = ptrace_check_attach(child, request == PTRACE_KILL); | |
874 | if (!ret) | |
875 | ret = compat_arch_ptrace(child, request, addr, data); | |
876 | ||
877 | out_put_task_struct: | |
878 | put_task_struct(child); | |
879 | out: | |
c269f196 RM |
880 | return ret; |
881 | } | |
96b8936a | 882 | #endif /* CONFIG_COMPAT */ |
bf26c018 FW |
883 | |
884 | #ifdef CONFIG_HAVE_HW_BREAKPOINT | |
885 | int ptrace_get_breakpoints(struct task_struct *tsk) | |
886 | { | |
887 | if (atomic_inc_not_zero(&tsk->ptrace_bp_refcnt)) | |
888 | return 0; | |
889 | ||
890 | return -1; | |
891 | } | |
892 | ||
893 | void ptrace_put_breakpoints(struct task_struct *tsk) | |
894 | { | |
895 | if (atomic_dec_and_test(&tsk->ptrace_bp_refcnt)) | |
896 | flush_ptrace_hw_breakpoint(tsk); | |
897 | } | |
898 | #endif /* CONFIG_HAVE_HW_BREAKPOINT */ |