Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * linux/kernel/ptrace.c | |
3 | * | |
4 | * (C) Copyright 1999 Linus Torvalds | |
5 | * | |
6 | * Common interfaces for "ptrace()" which we do not want | |
7 | * to continually duplicate across every architecture. | |
8 | */ | |
9 | ||
c59ede7b | 10 | #include <linux/capability.h> |
1da177e4 LT |
11 | #include <linux/module.h> |
12 | #include <linux/sched.h> | |
13 | #include <linux/errno.h> | |
14 | #include <linux/mm.h> | |
15 | #include <linux/highmem.h> | |
16 | #include <linux/pagemap.h> | |
1da177e4 LT |
17 | #include <linux/ptrace.h> |
18 | #include <linux/security.h> | |
7ed20e1a | 19 | #include <linux/signal.h> |
a5cb013d | 20 | #include <linux/audit.h> |
b488893a | 21 | #include <linux/pid_namespace.h> |
f17d30a8 | 22 | #include <linux/syscalls.h> |
3a709703 | 23 | #include <linux/uaccess.h> |
2225a122 | 24 | #include <linux/regset.h> |
bf26c018 | 25 | #include <linux/hw_breakpoint.h> |
1da177e4 | 26 | |
bf53de90 | 27 | |
62c124ff TH |
28 | static int ptrace_trapping_sleep_fn(void *flags) |
29 | { | |
30 | schedule(); | |
31 | return 0; | |
32 | } | |
33 | ||
1da177e4 LT |
34 | /* |
35 | * ptrace a task: make the debugger its new parent and | |
36 | * move it to the ptrace list. | |
37 | * | |
38 | * Must be called with the tasklist lock write-held. | |
39 | */ | |
36c8b586 | 40 | void __ptrace_link(struct task_struct *child, struct task_struct *new_parent) |
1da177e4 | 41 | { |
f470021a RM |
42 | BUG_ON(!list_empty(&child->ptrace_entry)); |
43 | list_add(&child->ptrace_entry, &new_parent->ptraced); | |
1da177e4 | 44 | child->parent = new_parent; |
1da177e4 | 45 | } |
3a709703 | 46 | |
e3bd058f TH |
47 | /** |
48 | * __ptrace_unlink - unlink ptracee and restore its execution state | |
49 | * @child: ptracee to be unlinked | |
1da177e4 | 50 | * |
0e9f0a4a TH |
51 | * Remove @child from the ptrace list, move it back to the original parent, |
52 | * and restore the execution state so that it conforms to the group stop | |
53 | * state. | |
54 | * | |
55 | * Unlinking can happen via two paths - explicit PTRACE_DETACH or ptracer | |
56 | * exiting. For PTRACE_DETACH, unless the ptracee has been killed between | |
57 | * ptrace_check_attach() and here, it's guaranteed to be in TASK_TRACED. | |
58 | * If the ptracer is exiting, the ptracee can be in any state. | |
59 | * | |
60 | * After detach, the ptracee should be in a state which conforms to the | |
61 | * group stop. If the group is stopped or in the process of stopping, the | |
62 | * ptracee should be put into TASK_STOPPED; otherwise, it should be woken | |
63 | * up from TASK_TRACED. | |
64 | * | |
65 | * If the ptracee is in TASK_TRACED and needs to be moved to TASK_STOPPED, | |
66 | * it goes through TRACED -> RUNNING -> STOPPED transition which is similar | |
67 | * to but in the opposite direction of what happens while attaching to a | |
68 | * stopped task. However, in this direction, the intermediate RUNNING | |
69 | * state is not hidden even from the current ptracer and if it immediately | |
70 | * re-attaches and performs a WNOHANG wait(2), it may fail. | |
e3bd058f TH |
71 | * |
72 | * CONTEXT: | |
73 | * write_lock_irq(tasklist_lock) | |
1da177e4 | 74 | */ |
36c8b586 | 75 | void __ptrace_unlink(struct task_struct *child) |
1da177e4 | 76 | { |
5ecfbae0 ON |
77 | BUG_ON(!child->ptrace); |
78 | ||
1da177e4 | 79 | child->ptrace = 0; |
f470021a RM |
80 | child->parent = child->real_parent; |
81 | list_del_init(&child->ptrace_entry); | |
1da177e4 | 82 | |
1da177e4 | 83 | spin_lock(&child->sighand->siglock); |
0e9f0a4a | 84 | |
73ddff2b TH |
85 | /* |
86 | * Clear all pending traps and TRAPPING. TRAPPING should be | |
87 | * cleared regardless of JOBCTL_STOP_PENDING. Do it explicitly. | |
88 | */ | |
89 | task_clear_jobctl_pending(child, JOBCTL_TRAP_MASK); | |
90 | task_clear_jobctl_trapping(child); | |
91 | ||
0e9f0a4a | 92 | /* |
a8f072c1 | 93 | * Reinstate JOBCTL_STOP_PENDING if group stop is in effect and |
0e9f0a4a TH |
94 | * @child isn't dead. |
95 | */ | |
96 | if (!(child->flags & PF_EXITING) && | |
97 | (child->signal->flags & SIGNAL_STOP_STOPPED || | |
98 | child->signal->group_stop_count)) | |
a8f072c1 | 99 | child->jobctl |= JOBCTL_STOP_PENDING; |
0e9f0a4a TH |
100 | |
101 | /* | |
102 | * If transition to TASK_STOPPED is pending or in TASK_TRACED, kick | |
103 | * @child in the butt. Note that @resume should be used iff @child | |
104 | * is in TASK_TRACED; otherwise, we might unduly disrupt | |
105 | * TASK_KILLABLE sleeps. | |
106 | */ | |
a8f072c1 | 107 | if (child->jobctl & JOBCTL_STOP_PENDING || task_is_traced(child)) |
0e9f0a4a TH |
108 | signal_wake_up(child, task_is_traced(child)); |
109 | ||
1da177e4 | 110 | spin_unlock(&child->sighand->siglock); |
1da177e4 LT |
111 | } |
112 | ||
755e276b TH |
113 | /** |
114 | * ptrace_check_attach - check whether ptracee is ready for ptrace operation | |
115 | * @child: ptracee to check for | |
116 | * @ignore_state: don't check whether @child is currently %TASK_TRACED | |
117 | * | |
118 | * Check whether @child is being ptraced by %current and ready for further | |
119 | * ptrace operations. If @ignore_state is %false, @child also should be in | |
120 | * %TASK_TRACED state and on return the child is guaranteed to be traced | |
121 | * and not executing. If @ignore_state is %true, @child can be in any | |
122 | * state. | |
123 | * | |
124 | * CONTEXT: | |
125 | * Grabs and releases tasklist_lock and @child->sighand->siglock. | |
126 | * | |
127 | * RETURNS: | |
128 | * 0 on success, -ESRCH if %child is not ready. | |
1da177e4 | 129 | */ |
755e276b | 130 | int ptrace_check_attach(struct task_struct *child, bool ignore_state) |
1da177e4 LT |
131 | { |
132 | int ret = -ESRCH; | |
133 | ||
134 | /* | |
135 | * We take the read lock around doing both checks to close a | |
136 | * possible race where someone else was tracing our child and | |
137 | * detached between these two checks. After this locked check, | |
138 | * we are sure that this is our traced child and that can only | |
139 | * be changed by us so it's not changing right after this. | |
140 | */ | |
141 | read_lock(&tasklist_lock); | |
c0c0b649 | 142 | if ((child->ptrace & PT_PTRACED) && child->parent == current) { |
c0c0b649 ON |
143 | /* |
144 | * child->sighand can't be NULL, release_task() | |
145 | * does ptrace_unlink() before __exit_signal(). | |
146 | */ | |
1da177e4 | 147 | spin_lock_irq(&child->sighand->siglock); |
321fb561 | 148 | WARN_ON_ONCE(task_is_stopped(child)); |
544b2c91 TH |
149 | if (ignore_state || (task_is_traced(child) && |
150 | !(child->jobctl & JOBCTL_LISTENING))) | |
321fb561 | 151 | ret = 0; |
1da177e4 LT |
152 | spin_unlock_irq(&child->sighand->siglock); |
153 | } | |
154 | read_unlock(&tasklist_lock); | |
155 | ||
755e276b | 156 | if (!ret && !ignore_state) |
85ba2d86 | 157 | ret = wait_task_inactive(child, TASK_TRACED) ? 0 : -ESRCH; |
1da177e4 LT |
158 | |
159 | /* All systems go.. */ | |
160 | return ret; | |
161 | } | |
162 | ||
006ebb40 | 163 | int __ptrace_may_access(struct task_struct *task, unsigned int mode) |
ab8d11be | 164 | { |
c69e8d9c | 165 | const struct cred *cred = current_cred(), *tcred; |
b6dff3ec | 166 | |
df26c40e EB |
167 | /* May we inspect the given task? |
168 | * This check is used both for attaching with ptrace | |
169 | * and for allowing access to sensitive information in /proc. | |
170 | * | |
171 | * ptrace_attach denies several cases that /proc allows | |
172 | * because setting up the necessary parent/child relationship | |
173 | * or halting the specified task is impossible. | |
174 | */ | |
175 | int dumpable = 0; | |
176 | /* Don't let security modules deny introspection */ | |
177 | if (task == current) | |
178 | return 0; | |
c69e8d9c DH |
179 | rcu_read_lock(); |
180 | tcred = __task_cred(task); | |
8409cca7 SH |
181 | if (cred->user->user_ns == tcred->user->user_ns && |
182 | (cred->uid == tcred->euid && | |
183 | cred->uid == tcred->suid && | |
184 | cred->uid == tcred->uid && | |
185 | cred->gid == tcred->egid && | |
186 | cred->gid == tcred->sgid && | |
187 | cred->gid == tcred->gid)) | |
188 | goto ok; | |
189 | if (ns_capable(tcred->user->user_ns, CAP_SYS_PTRACE)) | |
190 | goto ok; | |
191 | rcu_read_unlock(); | |
192 | return -EPERM; | |
193 | ok: | |
c69e8d9c | 194 | rcu_read_unlock(); |
ab8d11be | 195 | smp_rmb(); |
df26c40e | 196 | if (task->mm) |
6c5d5238 | 197 | dumpable = get_dumpable(task->mm); |
8409cca7 | 198 | if (!dumpable && !task_ns_capable(task, CAP_SYS_PTRACE)) |
ab8d11be MS |
199 | return -EPERM; |
200 | ||
9e48858f | 201 | return security_ptrace_access_check(task, mode); |
ab8d11be MS |
202 | } |
203 | ||
006ebb40 | 204 | bool ptrace_may_access(struct task_struct *task, unsigned int mode) |
ab8d11be MS |
205 | { |
206 | int err; | |
207 | task_lock(task); | |
006ebb40 | 208 | err = __ptrace_may_access(task, mode); |
ab8d11be | 209 | task_unlock(task); |
3a709703 | 210 | return !err; |
ab8d11be MS |
211 | } |
212 | ||
3544d72a TH |
213 | static int ptrace_attach(struct task_struct *task, long request, |
214 | unsigned long flags) | |
1da177e4 | 215 | { |
3544d72a | 216 | bool seize = (request == PTRACE_SEIZE); |
1da177e4 | 217 | int retval; |
f5b40e36 | 218 | |
3544d72a TH |
219 | /* |
220 | * SEIZE will enable new ptrace behaviors which will be implemented | |
221 | * gradually. SEIZE_DEVEL is used to prevent applications | |
222 | * expecting full SEIZE behaviors trapping on kernel commits which | |
223 | * are still in the process of implementing them. | |
224 | * | |
225 | * Only test programs for new ptrace behaviors being implemented | |
226 | * should set SEIZE_DEVEL. If unset, SEIZE will fail with -EIO. | |
227 | * | |
228 | * Once SEIZE behaviors are completely implemented, this flag and | |
229 | * the following test will be removed. | |
230 | */ | |
231 | retval = -EIO; | |
232 | if (seize && !(flags & PTRACE_SEIZE_DEVEL)) | |
233 | goto out; | |
234 | ||
a5cb013d AV |
235 | audit_ptrace(task); |
236 | ||
1da177e4 | 237 | retval = -EPERM; |
b79b7ba9 ON |
238 | if (unlikely(task->flags & PF_KTHREAD)) |
239 | goto out; | |
bac0abd6 | 240 | if (same_thread_group(task, current)) |
f5b40e36 LT |
241 | goto out; |
242 | ||
f2f0b00a ON |
243 | /* |
244 | * Protect exec's credential calculations against our interference; | |
5e751e99 DH |
245 | * interference; SUID, SGID and LSM creds get determined differently |
246 | * under ptrace. | |
d84f4f99 | 247 | */ |
793285fc | 248 | retval = -ERESTARTNOINTR; |
9b1bf12d | 249 | if (mutex_lock_interruptible(&task->signal->cred_guard_mutex)) |
d84f4f99 | 250 | goto out; |
f5b40e36 | 251 | |
4b105cbb | 252 | task_lock(task); |
006ebb40 | 253 | retval = __ptrace_may_access(task, PTRACE_MODE_ATTACH); |
4b105cbb | 254 | task_unlock(task); |
1da177e4 | 255 | if (retval) |
4b105cbb | 256 | goto unlock_creds; |
1da177e4 | 257 | |
4b105cbb | 258 | write_lock_irq(&tasklist_lock); |
b79b7ba9 ON |
259 | retval = -EPERM; |
260 | if (unlikely(task->exit_state)) | |
4b105cbb | 261 | goto unlock_tasklist; |
f2f0b00a | 262 | if (task->ptrace) |
4b105cbb | 263 | goto unlock_tasklist; |
b79b7ba9 | 264 | |
f2f0b00a | 265 | task->ptrace = PT_PTRACED; |
3544d72a TH |
266 | if (seize) |
267 | task->ptrace |= PT_SEIZED; | |
8409cca7 | 268 | if (task_ns_capable(task, CAP_SYS_PTRACE)) |
1da177e4 | 269 | task->ptrace |= PT_PTRACE_CAP; |
1da177e4 | 270 | |
1da177e4 | 271 | __ptrace_link(task, current); |
3544d72a TH |
272 | |
273 | /* SEIZE doesn't trap tracee on attach */ | |
274 | if (!seize) | |
275 | send_sig_info(SIGSTOP, SEND_SIG_FORCED, task); | |
b79b7ba9 | 276 | |
d79fdd6d TH |
277 | spin_lock(&task->sighand->siglock); |
278 | ||
279 | /* | |
73ddff2b | 280 | * If the task is already STOPPED, set JOBCTL_TRAP_STOP and |
d79fdd6d TH |
281 | * TRAPPING, and kick it so that it transits to TRACED. TRAPPING |
282 | * will be cleared if the child completes the transition or any | |
283 | * event which clears the group stop states happens. We'll wait | |
284 | * for the transition to complete before returning from this | |
285 | * function. | |
286 | * | |
287 | * This hides STOPPED -> RUNNING -> TRACED transition from the | |
288 | * attaching thread but a different thread in the same group can | |
289 | * still observe the transient RUNNING state. IOW, if another | |
290 | * thread's WNOHANG wait(2) on the stopped tracee races against | |
291 | * ATTACH, the wait(2) may fail due to the transient RUNNING. | |
292 | * | |
293 | * The following task_is_stopped() test is safe as both transitions | |
294 | * in and out of STOPPED are protected by siglock. | |
295 | */ | |
7dd3db54 | 296 | if (task_is_stopped(task) && |
73ddff2b | 297 | task_set_jobctl_pending(task, JOBCTL_TRAP_STOP | JOBCTL_TRAPPING)) |
d79fdd6d | 298 | signal_wake_up(task, 1); |
d79fdd6d TH |
299 | |
300 | spin_unlock(&task->sighand->siglock); | |
301 | ||
b79b7ba9 | 302 | retval = 0; |
4b105cbb ON |
303 | unlock_tasklist: |
304 | write_unlock_irq(&tasklist_lock); | |
305 | unlock_creds: | |
9b1bf12d | 306 | mutex_unlock(&task->signal->cred_guard_mutex); |
f5b40e36 | 307 | out: |
0b1007c3 | 308 | if (!retval) |
62c124ff TH |
309 | wait_on_bit(&task->jobctl, JOBCTL_TRAPPING_BIT, |
310 | ptrace_trapping_sleep_fn, TASK_UNINTERRUPTIBLE); | |
1da177e4 LT |
311 | return retval; |
312 | } | |
313 | ||
f2f0b00a ON |
314 | /** |
315 | * ptrace_traceme -- helper for PTRACE_TRACEME | |
316 | * | |
317 | * Performs checks and sets PT_PTRACED. | |
318 | * Should be used by all ptrace implementations for PTRACE_TRACEME. | |
319 | */ | |
e3e89cc5 | 320 | static int ptrace_traceme(void) |
f2f0b00a ON |
321 | { |
322 | int ret = -EPERM; | |
323 | ||
4b105cbb ON |
324 | write_lock_irq(&tasklist_lock); |
325 | /* Are we already being traced? */ | |
f2f0b00a | 326 | if (!current->ptrace) { |
f2f0b00a | 327 | ret = security_ptrace_traceme(current->parent); |
f2f0b00a ON |
328 | /* |
329 | * Check PF_EXITING to ensure ->real_parent has not passed | |
330 | * exit_ptrace(). Otherwise we don't report the error but | |
331 | * pretend ->real_parent untraces us right after return. | |
332 | */ | |
333 | if (!ret && !(current->real_parent->flags & PF_EXITING)) { | |
334 | current->ptrace = PT_PTRACED; | |
335 | __ptrace_link(current, current->real_parent); | |
336 | } | |
f2f0b00a | 337 | } |
4b105cbb ON |
338 | write_unlock_irq(&tasklist_lock); |
339 | ||
f2f0b00a ON |
340 | return ret; |
341 | } | |
342 | ||
39c626ae ON |
343 | /* |
344 | * Called with irqs disabled, returns true if childs should reap themselves. | |
345 | */ | |
346 | static int ignoring_children(struct sighand_struct *sigh) | |
347 | { | |
348 | int ret; | |
349 | spin_lock(&sigh->siglock); | |
350 | ret = (sigh->action[SIGCHLD-1].sa.sa_handler == SIG_IGN) || | |
351 | (sigh->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT); | |
352 | spin_unlock(&sigh->siglock); | |
353 | return ret; | |
354 | } | |
355 | ||
356 | /* | |
357 | * Called with tasklist_lock held for writing. | |
358 | * Unlink a traced task, and clean it up if it was a traced zombie. | |
359 | * Return true if it needs to be reaped with release_task(). | |
360 | * (We can't call release_task() here because we already hold tasklist_lock.) | |
361 | * | |
362 | * If it's a zombie, our attachedness prevented normal parent notification | |
363 | * or self-reaping. Do notification now if it would have happened earlier. | |
364 | * If it should reap itself, return true. | |
365 | * | |
a7f0765e ON |
366 | * If it's our own child, there is no notification to do. But if our normal |
367 | * children self-reap, then this child was prevented by ptrace and we must | |
368 | * reap it now, in that case we must also wake up sub-threads sleeping in | |
369 | * do_wait(). | |
39c626ae ON |
370 | */ |
371 | static bool __ptrace_detach(struct task_struct *tracer, struct task_struct *p) | |
372 | { | |
373 | __ptrace_unlink(p); | |
374 | ||
375 | if (p->exit_state == EXIT_ZOMBIE) { | |
376 | if (!task_detached(p) && thread_group_empty(p)) { | |
377 | if (!same_thread_group(p->real_parent, tracer)) | |
378 | do_notify_parent(p, p->exit_signal); | |
a7f0765e ON |
379 | else if (ignoring_children(tracer->sighand)) { |
380 | __wake_up_parent(p, tracer); | |
39c626ae | 381 | p->exit_signal = -1; |
a7f0765e | 382 | } |
39c626ae ON |
383 | } |
384 | if (task_detached(p)) { | |
385 | /* Mark it as in the process of being reaped. */ | |
386 | p->exit_state = EXIT_DEAD; | |
387 | return true; | |
388 | } | |
389 | } | |
390 | ||
391 | return false; | |
392 | } | |
393 | ||
e3e89cc5 | 394 | static int ptrace_detach(struct task_struct *child, unsigned int data) |
1da177e4 | 395 | { |
39c626ae | 396 | bool dead = false; |
4576145c | 397 | |
7ed20e1a | 398 | if (!valid_signal(data)) |
5ecfbae0 | 399 | return -EIO; |
1da177e4 LT |
400 | |
401 | /* Architecture-specific hardware disable .. */ | |
402 | ptrace_disable(child); | |
7d941432 | 403 | clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); |
1da177e4 | 404 | |
95c3eb76 | 405 | write_lock_irq(&tasklist_lock); |
39c626ae ON |
406 | /* |
407 | * This child can be already killed. Make sure de_thread() or | |
408 | * our sub-thread doing do_wait() didn't do release_task() yet. | |
409 | */ | |
95c3eb76 ON |
410 | if (child->ptrace) { |
411 | child->exit_code = data; | |
4576145c | 412 | dead = __ptrace_detach(current, child); |
95c3eb76 | 413 | } |
1da177e4 LT |
414 | write_unlock_irq(&tasklist_lock); |
415 | ||
4576145c ON |
416 | if (unlikely(dead)) |
417 | release_task(child); | |
418 | ||
1da177e4 LT |
419 | return 0; |
420 | } | |
421 | ||
39c626ae | 422 | /* |
c7e49c14 ON |
423 | * Detach all tasks we were using ptrace on. Called with tasklist held |
424 | * for writing, and returns with it held too. But note it can release | |
425 | * and reacquire the lock. | |
39c626ae ON |
426 | */ |
427 | void exit_ptrace(struct task_struct *tracer) | |
c4b5ed25 NK |
428 | __releases(&tasklist_lock) |
429 | __acquires(&tasklist_lock) | |
39c626ae ON |
430 | { |
431 | struct task_struct *p, *n; | |
432 | LIST_HEAD(ptrace_dead); | |
433 | ||
c7e49c14 ON |
434 | if (likely(list_empty(&tracer->ptraced))) |
435 | return; | |
436 | ||
39c626ae ON |
437 | list_for_each_entry_safe(p, n, &tracer->ptraced, ptrace_entry) { |
438 | if (__ptrace_detach(tracer, p)) | |
439 | list_add(&p->ptrace_entry, &ptrace_dead); | |
440 | } | |
39c626ae | 441 | |
c7e49c14 | 442 | write_unlock_irq(&tasklist_lock); |
39c626ae ON |
443 | BUG_ON(!list_empty(&tracer->ptraced)); |
444 | ||
445 | list_for_each_entry_safe(p, n, &ptrace_dead, ptrace_entry) { | |
446 | list_del_init(&p->ptrace_entry); | |
447 | release_task(p); | |
448 | } | |
c7e49c14 ON |
449 | |
450 | write_lock_irq(&tasklist_lock); | |
39c626ae ON |
451 | } |
452 | ||
1da177e4 LT |
453 | int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len) |
454 | { | |
455 | int copied = 0; | |
456 | ||
457 | while (len > 0) { | |
458 | char buf[128]; | |
459 | int this_len, retval; | |
460 | ||
461 | this_len = (len > sizeof(buf)) ? sizeof(buf) : len; | |
462 | retval = access_process_vm(tsk, src, buf, this_len, 0); | |
463 | if (!retval) { | |
464 | if (copied) | |
465 | break; | |
466 | return -EIO; | |
467 | } | |
468 | if (copy_to_user(dst, buf, retval)) | |
469 | return -EFAULT; | |
470 | copied += retval; | |
471 | src += retval; | |
472 | dst += retval; | |
3a709703 | 473 | len -= retval; |
1da177e4 LT |
474 | } |
475 | return copied; | |
476 | } | |
477 | ||
478 | int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len) | |
479 | { | |
480 | int copied = 0; | |
481 | ||
482 | while (len > 0) { | |
483 | char buf[128]; | |
484 | int this_len, retval; | |
485 | ||
486 | this_len = (len > sizeof(buf)) ? sizeof(buf) : len; | |
487 | if (copy_from_user(buf, src, this_len)) | |
488 | return -EFAULT; | |
489 | retval = access_process_vm(tsk, dst, buf, this_len, 1); | |
490 | if (!retval) { | |
491 | if (copied) | |
492 | break; | |
493 | return -EIO; | |
494 | } | |
495 | copied += retval; | |
496 | src += retval; | |
497 | dst += retval; | |
3a709703 | 498 | len -= retval; |
1da177e4 LT |
499 | } |
500 | return copied; | |
501 | } | |
502 | ||
4abf9869 | 503 | static int ptrace_setoptions(struct task_struct *child, unsigned long data) |
1da177e4 LT |
504 | { |
505 | child->ptrace &= ~PT_TRACE_MASK; | |
506 | ||
507 | if (data & PTRACE_O_TRACESYSGOOD) | |
508 | child->ptrace |= PT_TRACESYSGOOD; | |
509 | ||
510 | if (data & PTRACE_O_TRACEFORK) | |
511 | child->ptrace |= PT_TRACE_FORK; | |
512 | ||
513 | if (data & PTRACE_O_TRACEVFORK) | |
514 | child->ptrace |= PT_TRACE_VFORK; | |
515 | ||
516 | if (data & PTRACE_O_TRACECLONE) | |
517 | child->ptrace |= PT_TRACE_CLONE; | |
518 | ||
519 | if (data & PTRACE_O_TRACEEXEC) | |
520 | child->ptrace |= PT_TRACE_EXEC; | |
521 | ||
522 | if (data & PTRACE_O_TRACEVFORKDONE) | |
523 | child->ptrace |= PT_TRACE_VFORK_DONE; | |
524 | ||
525 | if (data & PTRACE_O_TRACEEXIT) | |
526 | child->ptrace |= PT_TRACE_EXIT; | |
527 | ||
528 | return (data & ~PTRACE_O_MASK) ? -EINVAL : 0; | |
529 | } | |
530 | ||
e16b2781 | 531 | static int ptrace_getsiginfo(struct task_struct *child, siginfo_t *info) |
1da177e4 | 532 | { |
e4961254 | 533 | unsigned long flags; |
1da177e4 LT |
534 | int error = -ESRCH; |
535 | ||
e4961254 | 536 | if (lock_task_sighand(child, &flags)) { |
1da177e4 | 537 | error = -EINVAL; |
1da177e4 | 538 | if (likely(child->last_siginfo != NULL)) { |
e16b2781 | 539 | *info = *child->last_siginfo; |
1da177e4 LT |
540 | error = 0; |
541 | } | |
e4961254 | 542 | unlock_task_sighand(child, &flags); |
1da177e4 | 543 | } |
1da177e4 LT |
544 | return error; |
545 | } | |
546 | ||
e16b2781 | 547 | static int ptrace_setsiginfo(struct task_struct *child, const siginfo_t *info) |
1da177e4 | 548 | { |
e4961254 | 549 | unsigned long flags; |
1da177e4 LT |
550 | int error = -ESRCH; |
551 | ||
e4961254 | 552 | if (lock_task_sighand(child, &flags)) { |
1da177e4 | 553 | error = -EINVAL; |
1da177e4 | 554 | if (likely(child->last_siginfo != NULL)) { |
e16b2781 | 555 | *child->last_siginfo = *info; |
1da177e4 LT |
556 | error = 0; |
557 | } | |
e4961254 | 558 | unlock_task_sighand(child, &flags); |
1da177e4 | 559 | } |
1da177e4 LT |
560 | return error; |
561 | } | |
562 | ||
36df29d7 RM |
563 | |
564 | #ifdef PTRACE_SINGLESTEP | |
565 | #define is_singlestep(request) ((request) == PTRACE_SINGLESTEP) | |
566 | #else | |
567 | #define is_singlestep(request) 0 | |
568 | #endif | |
569 | ||
5b88abbf RM |
570 | #ifdef PTRACE_SINGLEBLOCK |
571 | #define is_singleblock(request) ((request) == PTRACE_SINGLEBLOCK) | |
572 | #else | |
573 | #define is_singleblock(request) 0 | |
574 | #endif | |
575 | ||
36df29d7 RM |
576 | #ifdef PTRACE_SYSEMU |
577 | #define is_sysemu_singlestep(request) ((request) == PTRACE_SYSEMU_SINGLESTEP) | |
578 | #else | |
579 | #define is_sysemu_singlestep(request) 0 | |
580 | #endif | |
581 | ||
4abf9869 NK |
582 | static int ptrace_resume(struct task_struct *child, long request, |
583 | unsigned long data) | |
36df29d7 RM |
584 | { |
585 | if (!valid_signal(data)) | |
586 | return -EIO; | |
587 | ||
588 | if (request == PTRACE_SYSCALL) | |
589 | set_tsk_thread_flag(child, TIF_SYSCALL_TRACE); | |
590 | else | |
591 | clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); | |
592 | ||
593 | #ifdef TIF_SYSCALL_EMU | |
594 | if (request == PTRACE_SYSEMU || request == PTRACE_SYSEMU_SINGLESTEP) | |
595 | set_tsk_thread_flag(child, TIF_SYSCALL_EMU); | |
596 | else | |
597 | clear_tsk_thread_flag(child, TIF_SYSCALL_EMU); | |
598 | #endif | |
599 | ||
5b88abbf RM |
600 | if (is_singleblock(request)) { |
601 | if (unlikely(!arch_has_block_step())) | |
602 | return -EIO; | |
603 | user_enable_block_step(child); | |
604 | } else if (is_singlestep(request) || is_sysemu_singlestep(request)) { | |
36df29d7 RM |
605 | if (unlikely(!arch_has_single_step())) |
606 | return -EIO; | |
607 | user_enable_single_step(child); | |
3a709703 | 608 | } else { |
36df29d7 | 609 | user_disable_single_step(child); |
3a709703 | 610 | } |
36df29d7 RM |
611 | |
612 | child->exit_code = data; | |
0666fb51 | 613 | wake_up_state(child, __TASK_TRACED); |
36df29d7 RM |
614 | |
615 | return 0; | |
616 | } | |
617 | ||
2225a122 SS |
618 | #ifdef CONFIG_HAVE_ARCH_TRACEHOOK |
619 | ||
620 | static const struct user_regset * | |
621 | find_regset(const struct user_regset_view *view, unsigned int type) | |
622 | { | |
623 | const struct user_regset *regset; | |
624 | int n; | |
625 | ||
626 | for (n = 0; n < view->n; ++n) { | |
627 | regset = view->regsets + n; | |
628 | if (regset->core_note_type == type) | |
629 | return regset; | |
630 | } | |
631 | ||
632 | return NULL; | |
633 | } | |
634 | ||
635 | static int ptrace_regset(struct task_struct *task, int req, unsigned int type, | |
636 | struct iovec *kiov) | |
637 | { | |
638 | const struct user_regset_view *view = task_user_regset_view(task); | |
639 | const struct user_regset *regset = find_regset(view, type); | |
640 | int regset_no; | |
641 | ||
642 | if (!regset || (kiov->iov_len % regset->size) != 0) | |
c6a0dd7e | 643 | return -EINVAL; |
2225a122 SS |
644 | |
645 | regset_no = regset - view->regsets; | |
646 | kiov->iov_len = min(kiov->iov_len, | |
647 | (__kernel_size_t) (regset->n * regset->size)); | |
648 | ||
649 | if (req == PTRACE_GETREGSET) | |
650 | return copy_regset_to_user(task, view, regset_no, 0, | |
651 | kiov->iov_len, kiov->iov_base); | |
652 | else | |
653 | return copy_regset_from_user(task, view, regset_no, 0, | |
654 | kiov->iov_len, kiov->iov_base); | |
655 | } | |
656 | ||
657 | #endif | |
658 | ||
1da177e4 | 659 | int ptrace_request(struct task_struct *child, long request, |
4abf9869 | 660 | unsigned long addr, unsigned long data) |
1da177e4 | 661 | { |
fca26f26 | 662 | bool seized = child->ptrace & PT_SEIZED; |
1da177e4 | 663 | int ret = -EIO; |
544b2c91 | 664 | siginfo_t siginfo, *si; |
9fed81dc NK |
665 | void __user *datavp = (void __user *) data; |
666 | unsigned long __user *datalp = datavp; | |
fca26f26 | 667 | unsigned long flags; |
1da177e4 LT |
668 | |
669 | switch (request) { | |
16c3e389 RM |
670 | case PTRACE_PEEKTEXT: |
671 | case PTRACE_PEEKDATA: | |
672 | return generic_ptrace_peekdata(child, addr, data); | |
673 | case PTRACE_POKETEXT: | |
674 | case PTRACE_POKEDATA: | |
675 | return generic_ptrace_pokedata(child, addr, data); | |
676 | ||
1da177e4 LT |
677 | #ifdef PTRACE_OLDSETOPTIONS |
678 | case PTRACE_OLDSETOPTIONS: | |
679 | #endif | |
680 | case PTRACE_SETOPTIONS: | |
681 | ret = ptrace_setoptions(child, data); | |
682 | break; | |
683 | case PTRACE_GETEVENTMSG: | |
9fed81dc | 684 | ret = put_user(child->ptrace_message, datalp); |
1da177e4 | 685 | break; |
e16b2781 | 686 | |
1da177e4 | 687 | case PTRACE_GETSIGINFO: |
e16b2781 RM |
688 | ret = ptrace_getsiginfo(child, &siginfo); |
689 | if (!ret) | |
9fed81dc | 690 | ret = copy_siginfo_to_user(datavp, &siginfo); |
1da177e4 | 691 | break; |
e16b2781 | 692 | |
1da177e4 | 693 | case PTRACE_SETSIGINFO: |
9fed81dc | 694 | if (copy_from_user(&siginfo, datavp, sizeof siginfo)) |
e16b2781 RM |
695 | ret = -EFAULT; |
696 | else | |
697 | ret = ptrace_setsiginfo(child, &siginfo); | |
1da177e4 | 698 | break; |
e16b2781 | 699 | |
fca26f26 TH |
700 | case PTRACE_INTERRUPT: |
701 | /* | |
702 | * Stop tracee without any side-effect on signal or job | |
703 | * control. At least one trap is guaranteed to happen | |
704 | * after this request. If @child is already trapped, the | |
705 | * current trap is not disturbed and another trap will | |
706 | * happen after the current trap is ended with PTRACE_CONT. | |
707 | * | |
708 | * The actual trap might not be PTRACE_EVENT_STOP trap but | |
709 | * the pending condition is cleared regardless. | |
710 | */ | |
711 | if (unlikely(!seized || !lock_task_sighand(child, &flags))) | |
712 | break; | |
713 | ||
544b2c91 TH |
714 | /* |
715 | * INTERRUPT doesn't disturb existing trap sans one | |
716 | * exception. If ptracer issued LISTEN for the current | |
717 | * STOP, this INTERRUPT should clear LISTEN and re-trap | |
718 | * tracee into STOP. | |
719 | */ | |
fca26f26 | 720 | if (likely(task_set_jobctl_pending(child, JOBCTL_TRAP_STOP))) |
544b2c91 TH |
721 | signal_wake_up(child, child->jobctl & JOBCTL_LISTENING); |
722 | ||
723 | unlock_task_sighand(child, &flags); | |
724 | ret = 0; | |
725 | break; | |
726 | ||
727 | case PTRACE_LISTEN: | |
728 | /* | |
729 | * Listen for events. Tracee must be in STOP. It's not | |
730 | * resumed per-se but is not considered to be in TRACED by | |
731 | * wait(2) or ptrace(2). If an async event (e.g. group | |
732 | * stop state change) happens, tracee will enter STOP trap | |
733 | * again. Alternatively, ptracer can issue INTERRUPT to | |
734 | * finish listening and re-trap tracee into STOP. | |
735 | */ | |
736 | if (unlikely(!seized || !lock_task_sighand(child, &flags))) | |
737 | break; | |
738 | ||
739 | si = child->last_siginfo; | |
740 | if (unlikely(!si || si->si_code >> 8 != PTRACE_EVENT_STOP)) | |
741 | break; | |
742 | ||
743 | child->jobctl |= JOBCTL_LISTENING; | |
744 | ||
745 | /* | |
746 | * If NOTIFY is set, it means event happened between start | |
747 | * of this trap and now. Trigger re-trap immediately. | |
748 | */ | |
749 | if (child->jobctl & JOBCTL_TRAP_NOTIFY) | |
750 | signal_wake_up(child, true); | |
fca26f26 TH |
751 | |
752 | unlock_task_sighand(child, &flags); | |
753 | ret = 0; | |
754 | break; | |
755 | ||
1bcf5482 AD |
756 | case PTRACE_DETACH: /* detach a process that was attached. */ |
757 | ret = ptrace_detach(child, data); | |
758 | break; | |
36df29d7 | 759 | |
9c1a1259 MF |
760 | #ifdef CONFIG_BINFMT_ELF_FDPIC |
761 | case PTRACE_GETFDPIC: { | |
e0129ef9 | 762 | struct mm_struct *mm = get_task_mm(child); |
9c1a1259 MF |
763 | unsigned long tmp = 0; |
764 | ||
e0129ef9 ON |
765 | ret = -ESRCH; |
766 | if (!mm) | |
767 | break; | |
768 | ||
9c1a1259 MF |
769 | switch (addr) { |
770 | case PTRACE_GETFDPIC_EXEC: | |
e0129ef9 | 771 | tmp = mm->context.exec_fdpic_loadmap; |
9c1a1259 MF |
772 | break; |
773 | case PTRACE_GETFDPIC_INTERP: | |
e0129ef9 | 774 | tmp = mm->context.interp_fdpic_loadmap; |
9c1a1259 MF |
775 | break; |
776 | default: | |
777 | break; | |
778 | } | |
e0129ef9 | 779 | mmput(mm); |
9c1a1259 | 780 | |
9fed81dc | 781 | ret = put_user(tmp, datalp); |
9c1a1259 MF |
782 | break; |
783 | } | |
784 | #endif | |
785 | ||
36df29d7 RM |
786 | #ifdef PTRACE_SINGLESTEP |
787 | case PTRACE_SINGLESTEP: | |
788 | #endif | |
5b88abbf RM |
789 | #ifdef PTRACE_SINGLEBLOCK |
790 | case PTRACE_SINGLEBLOCK: | |
791 | #endif | |
36df29d7 RM |
792 | #ifdef PTRACE_SYSEMU |
793 | case PTRACE_SYSEMU: | |
794 | case PTRACE_SYSEMU_SINGLESTEP: | |
795 | #endif | |
796 | case PTRACE_SYSCALL: | |
797 | case PTRACE_CONT: | |
798 | return ptrace_resume(child, request, data); | |
799 | ||
800 | case PTRACE_KILL: | |
801 | if (child->exit_state) /* already dead */ | |
802 | return 0; | |
803 | return ptrace_resume(child, request, SIGKILL); | |
804 | ||
2225a122 SS |
805 | #ifdef CONFIG_HAVE_ARCH_TRACEHOOK |
806 | case PTRACE_GETREGSET: | |
807 | case PTRACE_SETREGSET: | |
808 | { | |
809 | struct iovec kiov; | |
9fed81dc | 810 | struct iovec __user *uiov = datavp; |
2225a122 SS |
811 | |
812 | if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov))) | |
813 | return -EFAULT; | |
814 | ||
815 | if (__get_user(kiov.iov_base, &uiov->iov_base) || | |
816 | __get_user(kiov.iov_len, &uiov->iov_len)) | |
817 | return -EFAULT; | |
818 | ||
819 | ret = ptrace_regset(child, request, addr, &kiov); | |
820 | if (!ret) | |
821 | ret = __put_user(kiov.iov_len, &uiov->iov_len); | |
822 | break; | |
823 | } | |
824 | #endif | |
1da177e4 LT |
825 | default: |
826 | break; | |
827 | } | |
828 | ||
829 | return ret; | |
830 | } | |
481bed45 | 831 | |
8053bdd5 | 832 | static struct task_struct *ptrace_get_task_struct(pid_t pid) |
6b9c7ed8 CH |
833 | { |
834 | struct task_struct *child; | |
481bed45 | 835 | |
8053bdd5 | 836 | rcu_read_lock(); |
228ebcbe | 837 | child = find_task_by_vpid(pid); |
481bed45 CH |
838 | if (child) |
839 | get_task_struct(child); | |
8053bdd5 | 840 | rcu_read_unlock(); |
f400e198 | 841 | |
481bed45 | 842 | if (!child) |
6b9c7ed8 CH |
843 | return ERR_PTR(-ESRCH); |
844 | return child; | |
481bed45 CH |
845 | } |
846 | ||
0ac15559 CH |
847 | #ifndef arch_ptrace_attach |
848 | #define arch_ptrace_attach(child) do { } while (0) | |
849 | #endif | |
850 | ||
4abf9869 NK |
851 | SYSCALL_DEFINE4(ptrace, long, request, long, pid, unsigned long, addr, |
852 | unsigned long, data) | |
481bed45 CH |
853 | { |
854 | struct task_struct *child; | |
855 | long ret; | |
856 | ||
6b9c7ed8 CH |
857 | if (request == PTRACE_TRACEME) { |
858 | ret = ptrace_traceme(); | |
6ea6dd93 HS |
859 | if (!ret) |
860 | arch_ptrace_attach(current); | |
481bed45 | 861 | goto out; |
6b9c7ed8 CH |
862 | } |
863 | ||
864 | child = ptrace_get_task_struct(pid); | |
865 | if (IS_ERR(child)) { | |
866 | ret = PTR_ERR(child); | |
867 | goto out; | |
868 | } | |
481bed45 | 869 | |
3544d72a TH |
870 | if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) { |
871 | ret = ptrace_attach(child, request, data); | |
0ac15559 CH |
872 | /* |
873 | * Some architectures need to do book-keeping after | |
874 | * a ptrace attach. | |
875 | */ | |
876 | if (!ret) | |
877 | arch_ptrace_attach(child); | |
005f18df | 878 | goto out_put_task_struct; |
481bed45 CH |
879 | } |
880 | ||
fca26f26 TH |
881 | ret = ptrace_check_attach(child, request == PTRACE_KILL || |
882 | request == PTRACE_INTERRUPT); | |
481bed45 CH |
883 | if (ret < 0) |
884 | goto out_put_task_struct; | |
885 | ||
886 | ret = arch_ptrace(child, request, addr, data); | |
481bed45 CH |
887 | |
888 | out_put_task_struct: | |
889 | put_task_struct(child); | |
890 | out: | |
481bed45 CH |
891 | return ret; |
892 | } | |
76647323 | 893 | |
4abf9869 NK |
894 | int generic_ptrace_peekdata(struct task_struct *tsk, unsigned long addr, |
895 | unsigned long data) | |
76647323 AD |
896 | { |
897 | unsigned long tmp; | |
898 | int copied; | |
899 | ||
900 | copied = access_process_vm(tsk, addr, &tmp, sizeof(tmp), 0); | |
901 | if (copied != sizeof(tmp)) | |
902 | return -EIO; | |
903 | return put_user(tmp, (unsigned long __user *)data); | |
904 | } | |
f284ce72 | 905 | |
4abf9869 NK |
906 | int generic_ptrace_pokedata(struct task_struct *tsk, unsigned long addr, |
907 | unsigned long data) | |
f284ce72 AD |
908 | { |
909 | int copied; | |
910 | ||
911 | copied = access_process_vm(tsk, addr, &data, sizeof(data), 1); | |
912 | return (copied == sizeof(data)) ? 0 : -EIO; | |
913 | } | |
032d82d9 | 914 | |
96b8936a | 915 | #if defined CONFIG_COMPAT |
032d82d9 RM |
916 | #include <linux/compat.h> |
917 | ||
918 | int compat_ptrace_request(struct task_struct *child, compat_long_t request, | |
919 | compat_ulong_t addr, compat_ulong_t data) | |
920 | { | |
921 | compat_ulong_t __user *datap = compat_ptr(data); | |
922 | compat_ulong_t word; | |
e16b2781 | 923 | siginfo_t siginfo; |
032d82d9 RM |
924 | int ret; |
925 | ||
926 | switch (request) { | |
927 | case PTRACE_PEEKTEXT: | |
928 | case PTRACE_PEEKDATA: | |
929 | ret = access_process_vm(child, addr, &word, sizeof(word), 0); | |
930 | if (ret != sizeof(word)) | |
931 | ret = -EIO; | |
932 | else | |
933 | ret = put_user(word, datap); | |
934 | break; | |
935 | ||
936 | case PTRACE_POKETEXT: | |
937 | case PTRACE_POKEDATA: | |
938 | ret = access_process_vm(child, addr, &data, sizeof(data), 1); | |
939 | ret = (ret != sizeof(data) ? -EIO : 0); | |
940 | break; | |
941 | ||
942 | case PTRACE_GETEVENTMSG: | |
943 | ret = put_user((compat_ulong_t) child->ptrace_message, datap); | |
944 | break; | |
945 | ||
e16b2781 RM |
946 | case PTRACE_GETSIGINFO: |
947 | ret = ptrace_getsiginfo(child, &siginfo); | |
948 | if (!ret) | |
949 | ret = copy_siginfo_to_user32( | |
950 | (struct compat_siginfo __user *) datap, | |
951 | &siginfo); | |
952 | break; | |
953 | ||
954 | case PTRACE_SETSIGINFO: | |
955 | memset(&siginfo, 0, sizeof siginfo); | |
956 | if (copy_siginfo_from_user32( | |
957 | &siginfo, (struct compat_siginfo __user *) datap)) | |
958 | ret = -EFAULT; | |
959 | else | |
960 | ret = ptrace_setsiginfo(child, &siginfo); | |
961 | break; | |
2225a122 SS |
962 | #ifdef CONFIG_HAVE_ARCH_TRACEHOOK |
963 | case PTRACE_GETREGSET: | |
964 | case PTRACE_SETREGSET: | |
965 | { | |
966 | struct iovec kiov; | |
967 | struct compat_iovec __user *uiov = | |
968 | (struct compat_iovec __user *) datap; | |
969 | compat_uptr_t ptr; | |
970 | compat_size_t len; | |
971 | ||
972 | if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov))) | |
973 | return -EFAULT; | |
974 | ||
975 | if (__get_user(ptr, &uiov->iov_base) || | |
976 | __get_user(len, &uiov->iov_len)) | |
977 | return -EFAULT; | |
978 | ||
979 | kiov.iov_base = compat_ptr(ptr); | |
980 | kiov.iov_len = len; | |
981 | ||
982 | ret = ptrace_regset(child, request, addr, &kiov); | |
983 | if (!ret) | |
984 | ret = __put_user(kiov.iov_len, &uiov->iov_len); | |
985 | break; | |
986 | } | |
987 | #endif | |
e16b2781 | 988 | |
032d82d9 RM |
989 | default: |
990 | ret = ptrace_request(child, request, addr, data); | |
991 | } | |
992 | ||
993 | return ret; | |
994 | } | |
c269f196 | 995 | |
c269f196 RM |
996 | asmlinkage long compat_sys_ptrace(compat_long_t request, compat_long_t pid, |
997 | compat_long_t addr, compat_long_t data) | |
998 | { | |
999 | struct task_struct *child; | |
1000 | long ret; | |
1001 | ||
c269f196 RM |
1002 | if (request == PTRACE_TRACEME) { |
1003 | ret = ptrace_traceme(); | |
1004 | goto out; | |
1005 | } | |
1006 | ||
1007 | child = ptrace_get_task_struct(pid); | |
1008 | if (IS_ERR(child)) { | |
1009 | ret = PTR_ERR(child); | |
1010 | goto out; | |
1011 | } | |
1012 | ||
3544d72a TH |
1013 | if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) { |
1014 | ret = ptrace_attach(child, request, data); | |
c269f196 RM |
1015 | /* |
1016 | * Some architectures need to do book-keeping after | |
1017 | * a ptrace attach. | |
1018 | */ | |
1019 | if (!ret) | |
1020 | arch_ptrace_attach(child); | |
1021 | goto out_put_task_struct; | |
1022 | } | |
1023 | ||
fca26f26 TH |
1024 | ret = ptrace_check_attach(child, request == PTRACE_KILL || |
1025 | request == PTRACE_INTERRUPT); | |
c269f196 RM |
1026 | if (!ret) |
1027 | ret = compat_arch_ptrace(child, request, addr, data); | |
1028 | ||
1029 | out_put_task_struct: | |
1030 | put_task_struct(child); | |
1031 | out: | |
c269f196 RM |
1032 | return ret; |
1033 | } | |
96b8936a | 1034 | #endif /* CONFIG_COMPAT */ |
bf26c018 FW |
1035 | |
1036 | #ifdef CONFIG_HAVE_HW_BREAKPOINT | |
1037 | int ptrace_get_breakpoints(struct task_struct *tsk) | |
1038 | { | |
1039 | if (atomic_inc_not_zero(&tsk->ptrace_bp_refcnt)) | |
1040 | return 0; | |
1041 | ||
1042 | return -1; | |
1043 | } | |
1044 | ||
1045 | void ptrace_put_breakpoints(struct task_struct *tsk) | |
1046 | { | |
1047 | if (atomic_dec_and_test(&tsk->ptrace_bp_refcnt)) | |
1048 | flush_ptrace_hw_breakpoint(tsk); | |
1049 | } | |
1050 | #endif /* CONFIG_HAVE_HW_BREAKPOINT */ |