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> |
1da177e4 | 25 | |
bf53de90 | 26 | |
1da177e4 LT |
27 | /* |
28 | * ptrace a task: make the debugger its new parent and | |
29 | * move it to the ptrace list. | |
30 | * | |
31 | * Must be called with the tasklist lock write-held. | |
32 | */ | |
36c8b586 | 33 | void __ptrace_link(struct task_struct *child, struct task_struct *new_parent) |
1da177e4 | 34 | { |
f470021a RM |
35 | BUG_ON(!list_empty(&child->ptrace_entry)); |
36 | list_add(&child->ptrace_entry, &new_parent->ptraced); | |
1da177e4 | 37 | child->parent = new_parent; |
1da177e4 | 38 | } |
3a709703 | 39 | |
1da177e4 LT |
40 | /* |
41 | * Turn a tracing stop into a normal stop now, since with no tracer there | |
42 | * would be no way to wake it up with SIGCONT or SIGKILL. If there was a | |
43 | * signal sent that would resume the child, but didn't because it was in | |
44 | * TASK_TRACED, resume it now. | |
45 | * Requires that irqs be disabled. | |
46 | */ | |
b747c8c1 | 47 | static void ptrace_untrace(struct task_struct *child) |
1da177e4 LT |
48 | { |
49 | spin_lock(&child->sighand->siglock); | |
6618a3e2 | 50 | if (task_is_traced(child)) { |
1ee11844 | 51 | /* |
d79fdd6d TH |
52 | * If group stop is completed or in progress, it should |
53 | * participate in the group stop. Set GROUP_STOP_PENDING | |
54 | * before kicking it. | |
55 | * | |
56 | * This involves TRACED -> RUNNING -> STOPPED transition | |
57 | * which is similar to but in the opposite direction of | |
58 | * what happens while attaching to a stopped task. | |
59 | * However, in this direction, the intermediate RUNNING | |
60 | * state is not hidden even from the current ptracer and if | |
61 | * it immediately re-attaches and performs a WNOHANG | |
62 | * wait(2), it may fail. | |
1ee11844 ON |
63 | */ |
64 | if (child->signal->flags & SIGNAL_STOP_STOPPED || | |
65 | child->signal->group_stop_count) | |
d79fdd6d TH |
66 | child->group_stop |= GROUP_STOP_PENDING; |
67 | signal_wake_up(child, 1); | |
1da177e4 LT |
68 | } |
69 | spin_unlock(&child->sighand->siglock); | |
70 | } | |
71 | ||
72 | /* | |
73 | * unptrace a task: move it back to its original parent and | |
74 | * remove it from the ptrace list. | |
75 | * | |
76 | * Must be called with the tasklist lock write-held. | |
77 | */ | |
36c8b586 | 78 | void __ptrace_unlink(struct task_struct *child) |
1da177e4 | 79 | { |
5ecfbae0 ON |
80 | BUG_ON(!child->ptrace); |
81 | ||
1da177e4 | 82 | child->ptrace = 0; |
f470021a RM |
83 | child->parent = child->real_parent; |
84 | list_del_init(&child->ptrace_entry); | |
1da177e4 | 85 | |
6618a3e2 | 86 | if (task_is_traced(child)) |
e57a5059 | 87 | ptrace_untrace(child); |
1da177e4 LT |
88 | } |
89 | ||
90 | /* | |
91 | * Check that we have indeed attached to the thing.. | |
92 | */ | |
93 | int ptrace_check_attach(struct task_struct *child, int kill) | |
94 | { | |
95 | int ret = -ESRCH; | |
96 | ||
97 | /* | |
98 | * We take the read lock around doing both checks to close a | |
99 | * possible race where someone else was tracing our child and | |
100 | * detached between these two checks. After this locked check, | |
101 | * we are sure that this is our traced child and that can only | |
102 | * be changed by us so it's not changing right after this. | |
103 | */ | |
104 | read_lock(&tasklist_lock); | |
c0c0b649 | 105 | if ((child->ptrace & PT_PTRACED) && child->parent == current) { |
1da177e4 | 106 | ret = 0; |
c0c0b649 ON |
107 | /* |
108 | * child->sighand can't be NULL, release_task() | |
109 | * does ptrace_unlink() before __exit_signal(). | |
110 | */ | |
1da177e4 | 111 | spin_lock_irq(&child->sighand->siglock); |
d9ae90ac | 112 | if (task_is_stopped(child)) |
1da177e4 | 113 | child->state = TASK_TRACED; |
d9ae90ac | 114 | else if (!task_is_traced(child) && !kill) |
1da177e4 | 115 | ret = -ESRCH; |
1da177e4 LT |
116 | spin_unlock_irq(&child->sighand->siglock); |
117 | } | |
118 | read_unlock(&tasklist_lock); | |
119 | ||
d9ae90ac | 120 | if (!ret && !kill) |
85ba2d86 | 121 | ret = wait_task_inactive(child, TASK_TRACED) ? 0 : -ESRCH; |
1da177e4 LT |
122 | |
123 | /* All systems go.. */ | |
124 | return ret; | |
125 | } | |
126 | ||
006ebb40 | 127 | int __ptrace_may_access(struct task_struct *task, unsigned int mode) |
ab8d11be | 128 | { |
c69e8d9c | 129 | const struct cred *cred = current_cred(), *tcred; |
b6dff3ec | 130 | |
df26c40e EB |
131 | /* May we inspect the given task? |
132 | * This check is used both for attaching with ptrace | |
133 | * and for allowing access to sensitive information in /proc. | |
134 | * | |
135 | * ptrace_attach denies several cases that /proc allows | |
136 | * because setting up the necessary parent/child relationship | |
137 | * or halting the specified task is impossible. | |
138 | */ | |
139 | int dumpable = 0; | |
140 | /* Don't let security modules deny introspection */ | |
141 | if (task == current) | |
142 | return 0; | |
c69e8d9c DH |
143 | rcu_read_lock(); |
144 | tcred = __task_cred(task); | |
145 | if ((cred->uid != tcred->euid || | |
146 | cred->uid != tcred->suid || | |
147 | cred->uid != tcred->uid || | |
148 | cred->gid != tcred->egid || | |
149 | cred->gid != tcred->sgid || | |
150 | cred->gid != tcred->gid) && | |
151 | !capable(CAP_SYS_PTRACE)) { | |
152 | rcu_read_unlock(); | |
ab8d11be | 153 | return -EPERM; |
c69e8d9c DH |
154 | } |
155 | rcu_read_unlock(); | |
ab8d11be | 156 | smp_rmb(); |
df26c40e | 157 | if (task->mm) |
6c5d5238 | 158 | dumpable = get_dumpable(task->mm); |
df26c40e | 159 | if (!dumpable && !capable(CAP_SYS_PTRACE)) |
ab8d11be MS |
160 | return -EPERM; |
161 | ||
9e48858f | 162 | return security_ptrace_access_check(task, mode); |
ab8d11be MS |
163 | } |
164 | ||
006ebb40 | 165 | bool ptrace_may_access(struct task_struct *task, unsigned int mode) |
ab8d11be MS |
166 | { |
167 | int err; | |
168 | task_lock(task); | |
006ebb40 | 169 | err = __ptrace_may_access(task, mode); |
ab8d11be | 170 | task_unlock(task); |
3a709703 | 171 | return !err; |
ab8d11be MS |
172 | } |
173 | ||
e3e89cc5 | 174 | static int ptrace_attach(struct task_struct *task) |
1da177e4 | 175 | { |
d79fdd6d | 176 | bool wait_trap = false; |
1da177e4 | 177 | int retval; |
f5b40e36 | 178 | |
a5cb013d AV |
179 | audit_ptrace(task); |
180 | ||
1da177e4 | 181 | retval = -EPERM; |
b79b7ba9 ON |
182 | if (unlikely(task->flags & PF_KTHREAD)) |
183 | goto out; | |
bac0abd6 | 184 | if (same_thread_group(task, current)) |
f5b40e36 LT |
185 | goto out; |
186 | ||
f2f0b00a ON |
187 | /* |
188 | * Protect exec's credential calculations against our interference; | |
5e751e99 DH |
189 | * interference; SUID, SGID and LSM creds get determined differently |
190 | * under ptrace. | |
d84f4f99 | 191 | */ |
793285fc | 192 | retval = -ERESTARTNOINTR; |
9b1bf12d | 193 | if (mutex_lock_interruptible(&task->signal->cred_guard_mutex)) |
d84f4f99 | 194 | goto out; |
f5b40e36 | 195 | |
4b105cbb | 196 | task_lock(task); |
006ebb40 | 197 | retval = __ptrace_may_access(task, PTRACE_MODE_ATTACH); |
4b105cbb | 198 | task_unlock(task); |
1da177e4 | 199 | if (retval) |
4b105cbb | 200 | goto unlock_creds; |
1da177e4 | 201 | |
4b105cbb | 202 | write_lock_irq(&tasklist_lock); |
b79b7ba9 ON |
203 | retval = -EPERM; |
204 | if (unlikely(task->exit_state)) | |
4b105cbb | 205 | goto unlock_tasklist; |
f2f0b00a | 206 | if (task->ptrace) |
4b105cbb | 207 | goto unlock_tasklist; |
b79b7ba9 | 208 | |
f2f0b00a | 209 | task->ptrace = PT_PTRACED; |
1da177e4 LT |
210 | if (capable(CAP_SYS_PTRACE)) |
211 | task->ptrace |= PT_PTRACE_CAP; | |
1da177e4 | 212 | |
1da177e4 | 213 | __ptrace_link(task, current); |
33e9fc7d | 214 | send_sig_info(SIGSTOP, SEND_SIG_FORCED, task); |
b79b7ba9 | 215 | |
d79fdd6d TH |
216 | spin_lock(&task->sighand->siglock); |
217 | ||
218 | /* | |
219 | * If the task is already STOPPED, set GROUP_STOP_PENDING and | |
220 | * TRAPPING, and kick it so that it transits to TRACED. TRAPPING | |
221 | * will be cleared if the child completes the transition or any | |
222 | * event which clears the group stop states happens. We'll wait | |
223 | * for the transition to complete before returning from this | |
224 | * function. | |
225 | * | |
226 | * This hides STOPPED -> RUNNING -> TRACED transition from the | |
227 | * attaching thread but a different thread in the same group can | |
228 | * still observe the transient RUNNING state. IOW, if another | |
229 | * thread's WNOHANG wait(2) on the stopped tracee races against | |
230 | * ATTACH, the wait(2) may fail due to the transient RUNNING. | |
231 | * | |
232 | * The following task_is_stopped() test is safe as both transitions | |
233 | * in and out of STOPPED are protected by siglock. | |
234 | */ | |
235 | if (task_is_stopped(task)) { | |
236 | task->group_stop |= GROUP_STOP_PENDING | GROUP_STOP_TRAPPING; | |
237 | signal_wake_up(task, 1); | |
238 | wait_trap = true; | |
239 | } | |
240 | ||
241 | spin_unlock(&task->sighand->siglock); | |
242 | ||
b79b7ba9 | 243 | retval = 0; |
4b105cbb ON |
244 | unlock_tasklist: |
245 | write_unlock_irq(&tasklist_lock); | |
246 | unlock_creds: | |
9b1bf12d | 247 | mutex_unlock(&task->signal->cred_guard_mutex); |
f5b40e36 | 248 | out: |
d79fdd6d TH |
249 | if (wait_trap) |
250 | wait_event(current->signal->wait_chldexit, | |
251 | !(task->group_stop & GROUP_STOP_TRAPPING)); | |
1da177e4 LT |
252 | return retval; |
253 | } | |
254 | ||
f2f0b00a ON |
255 | /** |
256 | * ptrace_traceme -- helper for PTRACE_TRACEME | |
257 | * | |
258 | * Performs checks and sets PT_PTRACED. | |
259 | * Should be used by all ptrace implementations for PTRACE_TRACEME. | |
260 | */ | |
e3e89cc5 | 261 | static int ptrace_traceme(void) |
f2f0b00a ON |
262 | { |
263 | int ret = -EPERM; | |
264 | ||
4b105cbb ON |
265 | write_lock_irq(&tasklist_lock); |
266 | /* Are we already being traced? */ | |
f2f0b00a | 267 | if (!current->ptrace) { |
f2f0b00a | 268 | ret = security_ptrace_traceme(current->parent); |
f2f0b00a ON |
269 | /* |
270 | * Check PF_EXITING to ensure ->real_parent has not passed | |
271 | * exit_ptrace(). Otherwise we don't report the error but | |
272 | * pretend ->real_parent untraces us right after return. | |
273 | */ | |
274 | if (!ret && !(current->real_parent->flags & PF_EXITING)) { | |
275 | current->ptrace = PT_PTRACED; | |
276 | __ptrace_link(current, current->real_parent); | |
277 | } | |
f2f0b00a | 278 | } |
4b105cbb ON |
279 | write_unlock_irq(&tasklist_lock); |
280 | ||
f2f0b00a ON |
281 | return ret; |
282 | } | |
283 | ||
39c626ae ON |
284 | /* |
285 | * Called with irqs disabled, returns true if childs should reap themselves. | |
286 | */ | |
287 | static int ignoring_children(struct sighand_struct *sigh) | |
288 | { | |
289 | int ret; | |
290 | spin_lock(&sigh->siglock); | |
291 | ret = (sigh->action[SIGCHLD-1].sa.sa_handler == SIG_IGN) || | |
292 | (sigh->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT); | |
293 | spin_unlock(&sigh->siglock); | |
294 | return ret; | |
295 | } | |
296 | ||
297 | /* | |
298 | * Called with tasklist_lock held for writing. | |
299 | * Unlink a traced task, and clean it up if it was a traced zombie. | |
300 | * Return true if it needs to be reaped with release_task(). | |
301 | * (We can't call release_task() here because we already hold tasklist_lock.) | |
302 | * | |
303 | * If it's a zombie, our attachedness prevented normal parent notification | |
304 | * or self-reaping. Do notification now if it would have happened earlier. | |
305 | * If it should reap itself, return true. | |
306 | * | |
a7f0765e ON |
307 | * If it's our own child, there is no notification to do. But if our normal |
308 | * children self-reap, then this child was prevented by ptrace and we must | |
309 | * reap it now, in that case we must also wake up sub-threads sleeping in | |
310 | * do_wait(). | |
39c626ae ON |
311 | */ |
312 | static bool __ptrace_detach(struct task_struct *tracer, struct task_struct *p) | |
313 | { | |
314 | __ptrace_unlink(p); | |
315 | ||
316 | if (p->exit_state == EXIT_ZOMBIE) { | |
317 | if (!task_detached(p) && thread_group_empty(p)) { | |
318 | if (!same_thread_group(p->real_parent, tracer)) | |
319 | do_notify_parent(p, p->exit_signal); | |
a7f0765e ON |
320 | else if (ignoring_children(tracer->sighand)) { |
321 | __wake_up_parent(p, tracer); | |
39c626ae | 322 | p->exit_signal = -1; |
a7f0765e | 323 | } |
39c626ae ON |
324 | } |
325 | if (task_detached(p)) { | |
326 | /* Mark it as in the process of being reaped. */ | |
327 | p->exit_state = EXIT_DEAD; | |
328 | return true; | |
329 | } | |
330 | } | |
331 | ||
332 | return false; | |
333 | } | |
334 | ||
e3e89cc5 | 335 | static int ptrace_detach(struct task_struct *child, unsigned int data) |
1da177e4 | 336 | { |
39c626ae | 337 | bool dead = false; |
4576145c | 338 | |
7ed20e1a | 339 | if (!valid_signal(data)) |
5ecfbae0 | 340 | return -EIO; |
1da177e4 LT |
341 | |
342 | /* Architecture-specific hardware disable .. */ | |
343 | ptrace_disable(child); | |
7d941432 | 344 | clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); |
1da177e4 | 345 | |
95c3eb76 | 346 | write_lock_irq(&tasklist_lock); |
39c626ae ON |
347 | /* |
348 | * This child can be already killed. Make sure de_thread() or | |
349 | * our sub-thread doing do_wait() didn't do release_task() yet. | |
350 | */ | |
95c3eb76 ON |
351 | if (child->ptrace) { |
352 | child->exit_code = data; | |
4576145c | 353 | dead = __ptrace_detach(current, child); |
95c3eb76 | 354 | } |
1da177e4 LT |
355 | write_unlock_irq(&tasklist_lock); |
356 | ||
4576145c ON |
357 | if (unlikely(dead)) |
358 | release_task(child); | |
359 | ||
1da177e4 LT |
360 | return 0; |
361 | } | |
362 | ||
39c626ae | 363 | /* |
c7e49c14 ON |
364 | * Detach all tasks we were using ptrace on. Called with tasklist held |
365 | * for writing, and returns with it held too. But note it can release | |
366 | * and reacquire the lock. | |
39c626ae ON |
367 | */ |
368 | void exit_ptrace(struct task_struct *tracer) | |
c4b5ed25 NK |
369 | __releases(&tasklist_lock) |
370 | __acquires(&tasklist_lock) | |
39c626ae ON |
371 | { |
372 | struct task_struct *p, *n; | |
373 | LIST_HEAD(ptrace_dead); | |
374 | ||
c7e49c14 ON |
375 | if (likely(list_empty(&tracer->ptraced))) |
376 | return; | |
377 | ||
39c626ae ON |
378 | list_for_each_entry_safe(p, n, &tracer->ptraced, ptrace_entry) { |
379 | if (__ptrace_detach(tracer, p)) | |
380 | list_add(&p->ptrace_entry, &ptrace_dead); | |
381 | } | |
39c626ae | 382 | |
c7e49c14 | 383 | write_unlock_irq(&tasklist_lock); |
39c626ae ON |
384 | BUG_ON(!list_empty(&tracer->ptraced)); |
385 | ||
386 | list_for_each_entry_safe(p, n, &ptrace_dead, ptrace_entry) { | |
387 | list_del_init(&p->ptrace_entry); | |
388 | release_task(p); | |
389 | } | |
c7e49c14 ON |
390 | |
391 | write_lock_irq(&tasklist_lock); | |
39c626ae ON |
392 | } |
393 | ||
1da177e4 LT |
394 | int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len) |
395 | { | |
396 | int copied = 0; | |
397 | ||
398 | while (len > 0) { | |
399 | char buf[128]; | |
400 | int this_len, retval; | |
401 | ||
402 | this_len = (len > sizeof(buf)) ? sizeof(buf) : len; | |
403 | retval = access_process_vm(tsk, src, buf, this_len, 0); | |
404 | if (!retval) { | |
405 | if (copied) | |
406 | break; | |
407 | return -EIO; | |
408 | } | |
409 | if (copy_to_user(dst, buf, retval)) | |
410 | return -EFAULT; | |
411 | copied += retval; | |
412 | src += retval; | |
413 | dst += retval; | |
3a709703 | 414 | len -= retval; |
1da177e4 LT |
415 | } |
416 | return copied; | |
417 | } | |
418 | ||
419 | int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len) | |
420 | { | |
421 | int copied = 0; | |
422 | ||
423 | while (len > 0) { | |
424 | char buf[128]; | |
425 | int this_len, retval; | |
426 | ||
427 | this_len = (len > sizeof(buf)) ? sizeof(buf) : len; | |
428 | if (copy_from_user(buf, src, this_len)) | |
429 | return -EFAULT; | |
430 | retval = access_process_vm(tsk, dst, buf, this_len, 1); | |
431 | if (!retval) { | |
432 | if (copied) | |
433 | break; | |
434 | return -EIO; | |
435 | } | |
436 | copied += retval; | |
437 | src += retval; | |
438 | dst += retval; | |
3a709703 | 439 | len -= retval; |
1da177e4 LT |
440 | } |
441 | return copied; | |
442 | } | |
443 | ||
4abf9869 | 444 | static int ptrace_setoptions(struct task_struct *child, unsigned long data) |
1da177e4 LT |
445 | { |
446 | child->ptrace &= ~PT_TRACE_MASK; | |
447 | ||
448 | if (data & PTRACE_O_TRACESYSGOOD) | |
449 | child->ptrace |= PT_TRACESYSGOOD; | |
450 | ||
451 | if (data & PTRACE_O_TRACEFORK) | |
452 | child->ptrace |= PT_TRACE_FORK; | |
453 | ||
454 | if (data & PTRACE_O_TRACEVFORK) | |
455 | child->ptrace |= PT_TRACE_VFORK; | |
456 | ||
457 | if (data & PTRACE_O_TRACECLONE) | |
458 | child->ptrace |= PT_TRACE_CLONE; | |
459 | ||
460 | if (data & PTRACE_O_TRACEEXEC) | |
461 | child->ptrace |= PT_TRACE_EXEC; | |
462 | ||
463 | if (data & PTRACE_O_TRACEVFORKDONE) | |
464 | child->ptrace |= PT_TRACE_VFORK_DONE; | |
465 | ||
466 | if (data & PTRACE_O_TRACEEXIT) | |
467 | child->ptrace |= PT_TRACE_EXIT; | |
468 | ||
469 | return (data & ~PTRACE_O_MASK) ? -EINVAL : 0; | |
470 | } | |
471 | ||
e16b2781 | 472 | static int ptrace_getsiginfo(struct task_struct *child, siginfo_t *info) |
1da177e4 | 473 | { |
e4961254 | 474 | unsigned long flags; |
1da177e4 LT |
475 | int error = -ESRCH; |
476 | ||
e4961254 | 477 | if (lock_task_sighand(child, &flags)) { |
1da177e4 | 478 | error = -EINVAL; |
1da177e4 | 479 | if (likely(child->last_siginfo != NULL)) { |
e16b2781 | 480 | *info = *child->last_siginfo; |
1da177e4 LT |
481 | error = 0; |
482 | } | |
e4961254 | 483 | unlock_task_sighand(child, &flags); |
1da177e4 | 484 | } |
1da177e4 LT |
485 | return error; |
486 | } | |
487 | ||
e16b2781 | 488 | static int ptrace_setsiginfo(struct task_struct *child, const siginfo_t *info) |
1da177e4 | 489 | { |
e4961254 | 490 | unsigned long flags; |
1da177e4 LT |
491 | int error = -ESRCH; |
492 | ||
e4961254 | 493 | if (lock_task_sighand(child, &flags)) { |
1da177e4 | 494 | error = -EINVAL; |
1da177e4 | 495 | if (likely(child->last_siginfo != NULL)) { |
e16b2781 | 496 | *child->last_siginfo = *info; |
1da177e4 LT |
497 | error = 0; |
498 | } | |
e4961254 | 499 | unlock_task_sighand(child, &flags); |
1da177e4 | 500 | } |
1da177e4 LT |
501 | return error; |
502 | } | |
503 | ||
36df29d7 RM |
504 | |
505 | #ifdef PTRACE_SINGLESTEP | |
506 | #define is_singlestep(request) ((request) == PTRACE_SINGLESTEP) | |
507 | #else | |
508 | #define is_singlestep(request) 0 | |
509 | #endif | |
510 | ||
5b88abbf RM |
511 | #ifdef PTRACE_SINGLEBLOCK |
512 | #define is_singleblock(request) ((request) == PTRACE_SINGLEBLOCK) | |
513 | #else | |
514 | #define is_singleblock(request) 0 | |
515 | #endif | |
516 | ||
36df29d7 RM |
517 | #ifdef PTRACE_SYSEMU |
518 | #define is_sysemu_singlestep(request) ((request) == PTRACE_SYSEMU_SINGLESTEP) | |
519 | #else | |
520 | #define is_sysemu_singlestep(request) 0 | |
521 | #endif | |
522 | ||
4abf9869 NK |
523 | static int ptrace_resume(struct task_struct *child, long request, |
524 | unsigned long data) | |
36df29d7 RM |
525 | { |
526 | if (!valid_signal(data)) | |
527 | return -EIO; | |
528 | ||
529 | if (request == PTRACE_SYSCALL) | |
530 | set_tsk_thread_flag(child, TIF_SYSCALL_TRACE); | |
531 | else | |
532 | clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); | |
533 | ||
534 | #ifdef TIF_SYSCALL_EMU | |
535 | if (request == PTRACE_SYSEMU || request == PTRACE_SYSEMU_SINGLESTEP) | |
536 | set_tsk_thread_flag(child, TIF_SYSCALL_EMU); | |
537 | else | |
538 | clear_tsk_thread_flag(child, TIF_SYSCALL_EMU); | |
539 | #endif | |
540 | ||
5b88abbf RM |
541 | if (is_singleblock(request)) { |
542 | if (unlikely(!arch_has_block_step())) | |
543 | return -EIO; | |
544 | user_enable_block_step(child); | |
545 | } else if (is_singlestep(request) || is_sysemu_singlestep(request)) { | |
36df29d7 RM |
546 | if (unlikely(!arch_has_single_step())) |
547 | return -EIO; | |
548 | user_enable_single_step(child); | |
3a709703 | 549 | } else { |
36df29d7 | 550 | user_disable_single_step(child); |
3a709703 | 551 | } |
36df29d7 RM |
552 | |
553 | child->exit_code = data; | |
554 | wake_up_process(child); | |
555 | ||
556 | return 0; | |
557 | } | |
558 | ||
2225a122 SS |
559 | #ifdef CONFIG_HAVE_ARCH_TRACEHOOK |
560 | ||
561 | static const struct user_regset * | |
562 | find_regset(const struct user_regset_view *view, unsigned int type) | |
563 | { | |
564 | const struct user_regset *regset; | |
565 | int n; | |
566 | ||
567 | for (n = 0; n < view->n; ++n) { | |
568 | regset = view->regsets + n; | |
569 | if (regset->core_note_type == type) | |
570 | return regset; | |
571 | } | |
572 | ||
573 | return NULL; | |
574 | } | |
575 | ||
576 | static int ptrace_regset(struct task_struct *task, int req, unsigned int type, | |
577 | struct iovec *kiov) | |
578 | { | |
579 | const struct user_regset_view *view = task_user_regset_view(task); | |
580 | const struct user_regset *regset = find_regset(view, type); | |
581 | int regset_no; | |
582 | ||
583 | if (!regset || (kiov->iov_len % regset->size) != 0) | |
c6a0dd7e | 584 | return -EINVAL; |
2225a122 SS |
585 | |
586 | regset_no = regset - view->regsets; | |
587 | kiov->iov_len = min(kiov->iov_len, | |
588 | (__kernel_size_t) (regset->n * regset->size)); | |
589 | ||
590 | if (req == PTRACE_GETREGSET) | |
591 | return copy_regset_to_user(task, view, regset_no, 0, | |
592 | kiov->iov_len, kiov->iov_base); | |
593 | else | |
594 | return copy_regset_from_user(task, view, regset_no, 0, | |
595 | kiov->iov_len, kiov->iov_base); | |
596 | } | |
597 | ||
598 | #endif | |
599 | ||
1da177e4 | 600 | int ptrace_request(struct task_struct *child, long request, |
4abf9869 | 601 | unsigned long addr, unsigned long data) |
1da177e4 LT |
602 | { |
603 | int ret = -EIO; | |
e16b2781 | 604 | siginfo_t siginfo; |
9fed81dc NK |
605 | void __user *datavp = (void __user *) data; |
606 | unsigned long __user *datalp = datavp; | |
1da177e4 LT |
607 | |
608 | switch (request) { | |
16c3e389 RM |
609 | case PTRACE_PEEKTEXT: |
610 | case PTRACE_PEEKDATA: | |
611 | return generic_ptrace_peekdata(child, addr, data); | |
612 | case PTRACE_POKETEXT: | |
613 | case PTRACE_POKEDATA: | |
614 | return generic_ptrace_pokedata(child, addr, data); | |
615 | ||
1da177e4 LT |
616 | #ifdef PTRACE_OLDSETOPTIONS |
617 | case PTRACE_OLDSETOPTIONS: | |
618 | #endif | |
619 | case PTRACE_SETOPTIONS: | |
620 | ret = ptrace_setoptions(child, data); | |
621 | break; | |
622 | case PTRACE_GETEVENTMSG: | |
9fed81dc | 623 | ret = put_user(child->ptrace_message, datalp); |
1da177e4 | 624 | break; |
e16b2781 | 625 | |
1da177e4 | 626 | case PTRACE_GETSIGINFO: |
e16b2781 RM |
627 | ret = ptrace_getsiginfo(child, &siginfo); |
628 | if (!ret) | |
9fed81dc | 629 | ret = copy_siginfo_to_user(datavp, &siginfo); |
1da177e4 | 630 | break; |
e16b2781 | 631 | |
1da177e4 | 632 | case PTRACE_SETSIGINFO: |
9fed81dc | 633 | if (copy_from_user(&siginfo, datavp, sizeof siginfo)) |
e16b2781 RM |
634 | ret = -EFAULT; |
635 | else | |
636 | ret = ptrace_setsiginfo(child, &siginfo); | |
1da177e4 | 637 | break; |
e16b2781 | 638 | |
1bcf5482 AD |
639 | case PTRACE_DETACH: /* detach a process that was attached. */ |
640 | ret = ptrace_detach(child, data); | |
641 | break; | |
36df29d7 | 642 | |
9c1a1259 MF |
643 | #ifdef CONFIG_BINFMT_ELF_FDPIC |
644 | case PTRACE_GETFDPIC: { | |
e0129ef9 | 645 | struct mm_struct *mm = get_task_mm(child); |
9c1a1259 MF |
646 | unsigned long tmp = 0; |
647 | ||
e0129ef9 ON |
648 | ret = -ESRCH; |
649 | if (!mm) | |
650 | break; | |
651 | ||
9c1a1259 MF |
652 | switch (addr) { |
653 | case PTRACE_GETFDPIC_EXEC: | |
e0129ef9 | 654 | tmp = mm->context.exec_fdpic_loadmap; |
9c1a1259 MF |
655 | break; |
656 | case PTRACE_GETFDPIC_INTERP: | |
e0129ef9 | 657 | tmp = mm->context.interp_fdpic_loadmap; |
9c1a1259 MF |
658 | break; |
659 | default: | |
660 | break; | |
661 | } | |
e0129ef9 | 662 | mmput(mm); |
9c1a1259 | 663 | |
9fed81dc | 664 | ret = put_user(tmp, datalp); |
9c1a1259 MF |
665 | break; |
666 | } | |
667 | #endif | |
668 | ||
36df29d7 RM |
669 | #ifdef PTRACE_SINGLESTEP |
670 | case PTRACE_SINGLESTEP: | |
671 | #endif | |
5b88abbf RM |
672 | #ifdef PTRACE_SINGLEBLOCK |
673 | case PTRACE_SINGLEBLOCK: | |
674 | #endif | |
36df29d7 RM |
675 | #ifdef PTRACE_SYSEMU |
676 | case PTRACE_SYSEMU: | |
677 | case PTRACE_SYSEMU_SINGLESTEP: | |
678 | #endif | |
679 | case PTRACE_SYSCALL: | |
680 | case PTRACE_CONT: | |
681 | return ptrace_resume(child, request, data); | |
682 | ||
683 | case PTRACE_KILL: | |
684 | if (child->exit_state) /* already dead */ | |
685 | return 0; | |
686 | return ptrace_resume(child, request, SIGKILL); | |
687 | ||
2225a122 SS |
688 | #ifdef CONFIG_HAVE_ARCH_TRACEHOOK |
689 | case PTRACE_GETREGSET: | |
690 | case PTRACE_SETREGSET: | |
691 | { | |
692 | struct iovec kiov; | |
9fed81dc | 693 | struct iovec __user *uiov = datavp; |
2225a122 SS |
694 | |
695 | if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov))) | |
696 | return -EFAULT; | |
697 | ||
698 | if (__get_user(kiov.iov_base, &uiov->iov_base) || | |
699 | __get_user(kiov.iov_len, &uiov->iov_len)) | |
700 | return -EFAULT; | |
701 | ||
702 | ret = ptrace_regset(child, request, addr, &kiov); | |
703 | if (!ret) | |
704 | ret = __put_user(kiov.iov_len, &uiov->iov_len); | |
705 | break; | |
706 | } | |
707 | #endif | |
1da177e4 LT |
708 | default: |
709 | break; | |
710 | } | |
711 | ||
712 | return ret; | |
713 | } | |
481bed45 | 714 | |
8053bdd5 | 715 | static struct task_struct *ptrace_get_task_struct(pid_t pid) |
6b9c7ed8 CH |
716 | { |
717 | struct task_struct *child; | |
481bed45 | 718 | |
8053bdd5 | 719 | rcu_read_lock(); |
228ebcbe | 720 | child = find_task_by_vpid(pid); |
481bed45 CH |
721 | if (child) |
722 | get_task_struct(child); | |
8053bdd5 | 723 | rcu_read_unlock(); |
f400e198 | 724 | |
481bed45 | 725 | if (!child) |
6b9c7ed8 CH |
726 | return ERR_PTR(-ESRCH); |
727 | return child; | |
481bed45 CH |
728 | } |
729 | ||
0ac15559 CH |
730 | #ifndef arch_ptrace_attach |
731 | #define arch_ptrace_attach(child) do { } while (0) | |
732 | #endif | |
733 | ||
4abf9869 NK |
734 | SYSCALL_DEFINE4(ptrace, long, request, long, pid, unsigned long, addr, |
735 | unsigned long, data) | |
481bed45 CH |
736 | { |
737 | struct task_struct *child; | |
738 | long ret; | |
739 | ||
6b9c7ed8 CH |
740 | if (request == PTRACE_TRACEME) { |
741 | ret = ptrace_traceme(); | |
6ea6dd93 HS |
742 | if (!ret) |
743 | arch_ptrace_attach(current); | |
481bed45 | 744 | goto out; |
6b9c7ed8 CH |
745 | } |
746 | ||
747 | child = ptrace_get_task_struct(pid); | |
748 | if (IS_ERR(child)) { | |
749 | ret = PTR_ERR(child); | |
750 | goto out; | |
751 | } | |
481bed45 CH |
752 | |
753 | if (request == PTRACE_ATTACH) { | |
754 | ret = ptrace_attach(child); | |
0ac15559 CH |
755 | /* |
756 | * Some architectures need to do book-keeping after | |
757 | * a ptrace attach. | |
758 | */ | |
759 | if (!ret) | |
760 | arch_ptrace_attach(child); | |
005f18df | 761 | goto out_put_task_struct; |
481bed45 CH |
762 | } |
763 | ||
764 | ret = ptrace_check_attach(child, request == PTRACE_KILL); | |
765 | if (ret < 0) | |
766 | goto out_put_task_struct; | |
767 | ||
768 | ret = arch_ptrace(child, request, addr, data); | |
481bed45 CH |
769 | |
770 | out_put_task_struct: | |
771 | put_task_struct(child); | |
772 | out: | |
481bed45 CH |
773 | return ret; |
774 | } | |
76647323 | 775 | |
4abf9869 NK |
776 | int generic_ptrace_peekdata(struct task_struct *tsk, unsigned long addr, |
777 | unsigned long data) | |
76647323 AD |
778 | { |
779 | unsigned long tmp; | |
780 | int copied; | |
781 | ||
782 | copied = access_process_vm(tsk, addr, &tmp, sizeof(tmp), 0); | |
783 | if (copied != sizeof(tmp)) | |
784 | return -EIO; | |
785 | return put_user(tmp, (unsigned long __user *)data); | |
786 | } | |
f284ce72 | 787 | |
4abf9869 NK |
788 | int generic_ptrace_pokedata(struct task_struct *tsk, unsigned long addr, |
789 | unsigned long data) | |
f284ce72 AD |
790 | { |
791 | int copied; | |
792 | ||
793 | copied = access_process_vm(tsk, addr, &data, sizeof(data), 1); | |
794 | return (copied == sizeof(data)) ? 0 : -EIO; | |
795 | } | |
032d82d9 | 796 | |
96b8936a | 797 | #if defined CONFIG_COMPAT |
032d82d9 RM |
798 | #include <linux/compat.h> |
799 | ||
800 | int compat_ptrace_request(struct task_struct *child, compat_long_t request, | |
801 | compat_ulong_t addr, compat_ulong_t data) | |
802 | { | |
803 | compat_ulong_t __user *datap = compat_ptr(data); | |
804 | compat_ulong_t word; | |
e16b2781 | 805 | siginfo_t siginfo; |
032d82d9 RM |
806 | int ret; |
807 | ||
808 | switch (request) { | |
809 | case PTRACE_PEEKTEXT: | |
810 | case PTRACE_PEEKDATA: | |
811 | ret = access_process_vm(child, addr, &word, sizeof(word), 0); | |
812 | if (ret != sizeof(word)) | |
813 | ret = -EIO; | |
814 | else | |
815 | ret = put_user(word, datap); | |
816 | break; | |
817 | ||
818 | case PTRACE_POKETEXT: | |
819 | case PTRACE_POKEDATA: | |
820 | ret = access_process_vm(child, addr, &data, sizeof(data), 1); | |
821 | ret = (ret != sizeof(data) ? -EIO : 0); | |
822 | break; | |
823 | ||
824 | case PTRACE_GETEVENTMSG: | |
825 | ret = put_user((compat_ulong_t) child->ptrace_message, datap); | |
826 | break; | |
827 | ||
e16b2781 RM |
828 | case PTRACE_GETSIGINFO: |
829 | ret = ptrace_getsiginfo(child, &siginfo); | |
830 | if (!ret) | |
831 | ret = copy_siginfo_to_user32( | |
832 | (struct compat_siginfo __user *) datap, | |
833 | &siginfo); | |
834 | break; | |
835 | ||
836 | case PTRACE_SETSIGINFO: | |
837 | memset(&siginfo, 0, sizeof siginfo); | |
838 | if (copy_siginfo_from_user32( | |
839 | &siginfo, (struct compat_siginfo __user *) datap)) | |
840 | ret = -EFAULT; | |
841 | else | |
842 | ret = ptrace_setsiginfo(child, &siginfo); | |
843 | break; | |
2225a122 SS |
844 | #ifdef CONFIG_HAVE_ARCH_TRACEHOOK |
845 | case PTRACE_GETREGSET: | |
846 | case PTRACE_SETREGSET: | |
847 | { | |
848 | struct iovec kiov; | |
849 | struct compat_iovec __user *uiov = | |
850 | (struct compat_iovec __user *) datap; | |
851 | compat_uptr_t ptr; | |
852 | compat_size_t len; | |
853 | ||
854 | if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov))) | |
855 | return -EFAULT; | |
856 | ||
857 | if (__get_user(ptr, &uiov->iov_base) || | |
858 | __get_user(len, &uiov->iov_len)) | |
859 | return -EFAULT; | |
860 | ||
861 | kiov.iov_base = compat_ptr(ptr); | |
862 | kiov.iov_len = len; | |
863 | ||
864 | ret = ptrace_regset(child, request, addr, &kiov); | |
865 | if (!ret) | |
866 | ret = __put_user(kiov.iov_len, &uiov->iov_len); | |
867 | break; | |
868 | } | |
869 | #endif | |
e16b2781 | 870 | |
032d82d9 RM |
871 | default: |
872 | ret = ptrace_request(child, request, addr, data); | |
873 | } | |
874 | ||
875 | return ret; | |
876 | } | |
c269f196 | 877 | |
c269f196 RM |
878 | asmlinkage long compat_sys_ptrace(compat_long_t request, compat_long_t pid, |
879 | compat_long_t addr, compat_long_t data) | |
880 | { | |
881 | struct task_struct *child; | |
882 | long ret; | |
883 | ||
c269f196 RM |
884 | if (request == PTRACE_TRACEME) { |
885 | ret = ptrace_traceme(); | |
886 | goto out; | |
887 | } | |
888 | ||
889 | child = ptrace_get_task_struct(pid); | |
890 | if (IS_ERR(child)) { | |
891 | ret = PTR_ERR(child); | |
892 | goto out; | |
893 | } | |
894 | ||
895 | if (request == PTRACE_ATTACH) { | |
896 | ret = ptrace_attach(child); | |
897 | /* | |
898 | * Some architectures need to do book-keeping after | |
899 | * a ptrace attach. | |
900 | */ | |
901 | if (!ret) | |
902 | arch_ptrace_attach(child); | |
903 | goto out_put_task_struct; | |
904 | } | |
905 | ||
906 | ret = ptrace_check_attach(child, request == PTRACE_KILL); | |
907 | if (!ret) | |
908 | ret = compat_arch_ptrace(child, request, addr, data); | |
909 | ||
910 | out_put_task_struct: | |
911 | put_task_struct(child); | |
912 | out: | |
c269f196 RM |
913 | return ret; |
914 | } | |
96b8936a | 915 | #endif /* CONFIG_COMPAT */ |