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> |
9984de1a | 11 | #include <linux/export.h> |
1da177e4 LT |
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> |
f701e5b7 | 26 | #include <linux/cn_proc.h> |
1da177e4 | 27 | |
bf53de90 | 28 | |
62c124ff TH |
29 | static int ptrace_trapping_sleep_fn(void *flags) |
30 | { | |
31 | schedule(); | |
32 | return 0; | |
33 | } | |
34 | ||
1da177e4 LT |
35 | /* |
36 | * ptrace a task: make the debugger its new parent and | |
37 | * move it to the ptrace list. | |
38 | * | |
39 | * Must be called with the tasklist lock write-held. | |
40 | */ | |
36c8b586 | 41 | void __ptrace_link(struct task_struct *child, struct task_struct *new_parent) |
1da177e4 | 42 | { |
f470021a RM |
43 | BUG_ON(!list_empty(&child->ptrace_entry)); |
44 | list_add(&child->ptrace_entry, &new_parent->ptraced); | |
1da177e4 | 45 | child->parent = new_parent; |
1da177e4 | 46 | } |
3a709703 | 47 | |
e3bd058f TH |
48 | /** |
49 | * __ptrace_unlink - unlink ptracee and restore its execution state | |
50 | * @child: ptracee to be unlinked | |
1da177e4 | 51 | * |
0e9f0a4a TH |
52 | * Remove @child from the ptrace list, move it back to the original parent, |
53 | * and restore the execution state so that it conforms to the group stop | |
54 | * state. | |
55 | * | |
56 | * Unlinking can happen via two paths - explicit PTRACE_DETACH or ptracer | |
57 | * exiting. For PTRACE_DETACH, unless the ptracee has been killed between | |
58 | * ptrace_check_attach() and here, it's guaranteed to be in TASK_TRACED. | |
59 | * If the ptracer is exiting, the ptracee can be in any state. | |
60 | * | |
61 | * After detach, the ptracee should be in a state which conforms to the | |
62 | * group stop. If the group is stopped or in the process of stopping, the | |
63 | * ptracee should be put into TASK_STOPPED; otherwise, it should be woken | |
64 | * up from TASK_TRACED. | |
65 | * | |
66 | * If the ptracee is in TASK_TRACED and needs to be moved to TASK_STOPPED, | |
67 | * it goes through TRACED -> RUNNING -> STOPPED transition which is similar | |
68 | * to but in the opposite direction of what happens while attaching to a | |
69 | * stopped task. However, in this direction, the intermediate RUNNING | |
70 | * state is not hidden even from the current ptracer and if it immediately | |
71 | * re-attaches and performs a WNOHANG wait(2), it may fail. | |
e3bd058f TH |
72 | * |
73 | * CONTEXT: | |
74 | * write_lock_irq(tasklist_lock) | |
1da177e4 | 75 | */ |
36c8b586 | 76 | void __ptrace_unlink(struct task_struct *child) |
1da177e4 | 77 | { |
5ecfbae0 ON |
78 | BUG_ON(!child->ptrace); |
79 | ||
1da177e4 | 80 | child->ptrace = 0; |
f470021a RM |
81 | child->parent = child->real_parent; |
82 | list_del_init(&child->ptrace_entry); | |
1da177e4 | 83 | |
1da177e4 | 84 | spin_lock(&child->sighand->siglock); |
0e9f0a4a | 85 | |
73ddff2b TH |
86 | /* |
87 | * Clear all pending traps and TRAPPING. TRAPPING should be | |
88 | * cleared regardless of JOBCTL_STOP_PENDING. Do it explicitly. | |
89 | */ | |
90 | task_clear_jobctl_pending(child, JOBCTL_TRAP_MASK); | |
91 | task_clear_jobctl_trapping(child); | |
92 | ||
0e9f0a4a | 93 | /* |
a8f072c1 | 94 | * Reinstate JOBCTL_STOP_PENDING if group stop is in effect and |
0e9f0a4a TH |
95 | * @child isn't dead. |
96 | */ | |
97 | if (!(child->flags & PF_EXITING) && | |
98 | (child->signal->flags & SIGNAL_STOP_STOPPED || | |
8a88951b | 99 | child->signal->group_stop_count)) { |
a8f072c1 | 100 | child->jobctl |= JOBCTL_STOP_PENDING; |
0e9f0a4a | 101 | |
8a88951b ON |
102 | /* |
103 | * This is only possible if this thread was cloned by the | |
104 | * traced task running in the stopped group, set the signal | |
105 | * for the future reports. | |
106 | * FIXME: we should change ptrace_init_task() to handle this | |
107 | * case. | |
108 | */ | |
109 | if (!(child->jobctl & JOBCTL_STOP_SIGMASK)) | |
110 | child->jobctl |= SIGSTOP; | |
111 | } | |
112 | ||
0e9f0a4a TH |
113 | /* |
114 | * If transition to TASK_STOPPED is pending or in TASK_TRACED, kick | |
115 | * @child in the butt. Note that @resume should be used iff @child | |
116 | * is in TASK_TRACED; otherwise, we might unduly disrupt | |
117 | * TASK_KILLABLE sleeps. | |
118 | */ | |
a8f072c1 | 119 | if (child->jobctl & JOBCTL_STOP_PENDING || task_is_traced(child)) |
910ffdb1 | 120 | ptrace_signal_wake_up(child, true); |
0e9f0a4a | 121 | |
1da177e4 | 122 | spin_unlock(&child->sighand->siglock); |
1da177e4 LT |
123 | } |
124 | ||
9899d11f ON |
125 | /* Ensure that nothing can wake it up, even SIGKILL */ |
126 | static bool ptrace_freeze_traced(struct task_struct *task) | |
127 | { | |
128 | bool ret = false; | |
129 | ||
130 | /* Lockless, nobody but us can set this flag */ | |
131 | if (task->jobctl & JOBCTL_LISTENING) | |
132 | return ret; | |
133 | ||
134 | spin_lock_irq(&task->sighand->siglock); | |
135 | if (task_is_traced(task) && !__fatal_signal_pending(task)) { | |
136 | task->state = __TASK_TRACED; | |
137 | ret = true; | |
138 | } | |
139 | spin_unlock_irq(&task->sighand->siglock); | |
140 | ||
141 | return ret; | |
142 | } | |
143 | ||
144 | static void ptrace_unfreeze_traced(struct task_struct *task) | |
145 | { | |
146 | if (task->state != __TASK_TRACED) | |
147 | return; | |
148 | ||
149 | WARN_ON(!task->ptrace || task->parent != current); | |
150 | ||
151 | spin_lock_irq(&task->sighand->siglock); | |
152 | if (__fatal_signal_pending(task)) | |
153 | wake_up_state(task, __TASK_TRACED); | |
154 | else | |
155 | task->state = TASK_TRACED; | |
156 | spin_unlock_irq(&task->sighand->siglock); | |
157 | } | |
158 | ||
755e276b TH |
159 | /** |
160 | * ptrace_check_attach - check whether ptracee is ready for ptrace operation | |
161 | * @child: ptracee to check for | |
162 | * @ignore_state: don't check whether @child is currently %TASK_TRACED | |
163 | * | |
164 | * Check whether @child is being ptraced by %current and ready for further | |
165 | * ptrace operations. If @ignore_state is %false, @child also should be in | |
166 | * %TASK_TRACED state and on return the child is guaranteed to be traced | |
167 | * and not executing. If @ignore_state is %true, @child can be in any | |
168 | * state. | |
169 | * | |
170 | * CONTEXT: | |
171 | * Grabs and releases tasklist_lock and @child->sighand->siglock. | |
172 | * | |
173 | * RETURNS: | |
174 | * 0 on success, -ESRCH if %child is not ready. | |
1da177e4 | 175 | */ |
edea0d03 | 176 | static int ptrace_check_attach(struct task_struct *child, bool ignore_state) |
1da177e4 LT |
177 | { |
178 | int ret = -ESRCH; | |
179 | ||
180 | /* | |
181 | * We take the read lock around doing both checks to close a | |
182 | * possible race where someone else was tracing our child and | |
183 | * detached between these two checks. After this locked check, | |
184 | * we are sure that this is our traced child and that can only | |
185 | * be changed by us so it's not changing right after this. | |
186 | */ | |
187 | read_lock(&tasklist_lock); | |
9899d11f ON |
188 | if (child->ptrace && child->parent == current) { |
189 | WARN_ON(child->state == __TASK_TRACED); | |
c0c0b649 ON |
190 | /* |
191 | * child->sighand can't be NULL, release_task() | |
192 | * does ptrace_unlink() before __exit_signal(). | |
193 | */ | |
9899d11f | 194 | if (ignore_state || ptrace_freeze_traced(child)) |
321fb561 | 195 | ret = 0; |
1da177e4 LT |
196 | } |
197 | read_unlock(&tasklist_lock); | |
198 | ||
9899d11f ON |
199 | if (!ret && !ignore_state) { |
200 | if (!wait_task_inactive(child, __TASK_TRACED)) { | |
201 | /* | |
202 | * This can only happen if may_ptrace_stop() fails and | |
203 | * ptrace_stop() changes ->state back to TASK_RUNNING, | |
204 | * so we should not worry about leaking __TASK_TRACED. | |
205 | */ | |
206 | WARN_ON(child->state == __TASK_TRACED); | |
207 | ret = -ESRCH; | |
208 | } | |
209 | } | |
1da177e4 | 210 | |
1da177e4 LT |
211 | return ret; |
212 | } | |
213 | ||
69f594a3 EP |
214 | static int ptrace_has_cap(struct user_namespace *ns, unsigned int mode) |
215 | { | |
216 | if (mode & PTRACE_MODE_NOAUDIT) | |
217 | return has_ns_capability_noaudit(current, ns, CAP_SYS_PTRACE); | |
218 | else | |
219 | return has_ns_capability(current, ns, CAP_SYS_PTRACE); | |
220 | } | |
221 | ||
9f99798f TH |
222 | /* Returns 0 on success, -errno on denial. */ |
223 | static int __ptrace_may_access(struct task_struct *task, unsigned int mode) | |
ab8d11be | 224 | { |
c69e8d9c | 225 | const struct cred *cred = current_cred(), *tcred; |
b6dff3ec | 226 | |
df26c40e EB |
227 | /* May we inspect the given task? |
228 | * This check is used both for attaching with ptrace | |
229 | * and for allowing access to sensitive information in /proc. | |
230 | * | |
231 | * ptrace_attach denies several cases that /proc allows | |
232 | * because setting up the necessary parent/child relationship | |
233 | * or halting the specified task is impossible. | |
234 | */ | |
235 | int dumpable = 0; | |
236 | /* Don't let security modules deny introspection */ | |
237 | if (task == current) | |
238 | return 0; | |
c69e8d9c DH |
239 | rcu_read_lock(); |
240 | tcred = __task_cred(task); | |
5af66203 EB |
241 | if (uid_eq(cred->uid, tcred->euid) && |
242 | uid_eq(cred->uid, tcred->suid) && | |
243 | uid_eq(cred->uid, tcred->uid) && | |
244 | gid_eq(cred->gid, tcred->egid) && | |
245 | gid_eq(cred->gid, tcred->sgid) && | |
246 | gid_eq(cred->gid, tcred->gid)) | |
8409cca7 | 247 | goto ok; |
c4a4d603 | 248 | if (ptrace_has_cap(tcred->user_ns, mode)) |
8409cca7 SH |
249 | goto ok; |
250 | rcu_read_unlock(); | |
251 | return -EPERM; | |
252 | ok: | |
c69e8d9c | 253 | rcu_read_unlock(); |
ab8d11be | 254 | smp_rmb(); |
df26c40e | 255 | if (task->mm) |
6c5d5238 | 256 | dumpable = get_dumpable(task->mm); |
4c44aaaf EB |
257 | rcu_read_lock(); |
258 | if (!dumpable && !ptrace_has_cap(__task_cred(task)->user_ns, mode)) { | |
259 | rcu_read_unlock(); | |
ab8d11be | 260 | return -EPERM; |
4c44aaaf EB |
261 | } |
262 | rcu_read_unlock(); | |
ab8d11be | 263 | |
9e48858f | 264 | return security_ptrace_access_check(task, mode); |
ab8d11be MS |
265 | } |
266 | ||
006ebb40 | 267 | bool ptrace_may_access(struct task_struct *task, unsigned int mode) |
ab8d11be MS |
268 | { |
269 | int err; | |
270 | task_lock(task); | |
006ebb40 | 271 | err = __ptrace_may_access(task, mode); |
ab8d11be | 272 | task_unlock(task); |
3a709703 | 273 | return !err; |
ab8d11be MS |
274 | } |
275 | ||
3544d72a | 276 | static int ptrace_attach(struct task_struct *task, long request, |
aa9147c9 | 277 | unsigned long addr, |
3544d72a | 278 | unsigned long flags) |
1da177e4 | 279 | { |
3544d72a | 280 | bool seize = (request == PTRACE_SEIZE); |
1da177e4 | 281 | int retval; |
f5b40e36 | 282 | |
3544d72a | 283 | retval = -EIO; |
aa9147c9 DV |
284 | if (seize) { |
285 | if (addr != 0) | |
286 | goto out; | |
aa9147c9 DV |
287 | if (flags & ~(unsigned long)PTRACE_O_MASK) |
288 | goto out; | |
289 | flags = PT_PTRACED | PT_SEIZED | (flags << PT_OPT_FLAG_SHIFT); | |
290 | } else { | |
291 | flags = PT_PTRACED; | |
292 | } | |
3544d72a | 293 | |
a5cb013d AV |
294 | audit_ptrace(task); |
295 | ||
1da177e4 | 296 | retval = -EPERM; |
b79b7ba9 ON |
297 | if (unlikely(task->flags & PF_KTHREAD)) |
298 | goto out; | |
bac0abd6 | 299 | if (same_thread_group(task, current)) |
f5b40e36 LT |
300 | goto out; |
301 | ||
f2f0b00a ON |
302 | /* |
303 | * Protect exec's credential calculations against our interference; | |
86b6c1f3 | 304 | * SUID, SGID and LSM creds get determined differently |
5e751e99 | 305 | * under ptrace. |
d84f4f99 | 306 | */ |
793285fc | 307 | retval = -ERESTARTNOINTR; |
9b1bf12d | 308 | if (mutex_lock_interruptible(&task->signal->cred_guard_mutex)) |
d84f4f99 | 309 | goto out; |
f5b40e36 | 310 | |
4b105cbb | 311 | task_lock(task); |
006ebb40 | 312 | retval = __ptrace_may_access(task, PTRACE_MODE_ATTACH); |
4b105cbb | 313 | task_unlock(task); |
1da177e4 | 314 | if (retval) |
4b105cbb | 315 | goto unlock_creds; |
1da177e4 | 316 | |
4b105cbb | 317 | write_lock_irq(&tasklist_lock); |
b79b7ba9 ON |
318 | retval = -EPERM; |
319 | if (unlikely(task->exit_state)) | |
4b105cbb | 320 | goto unlock_tasklist; |
f2f0b00a | 321 | if (task->ptrace) |
4b105cbb | 322 | goto unlock_tasklist; |
b79b7ba9 | 323 | |
3544d72a | 324 | if (seize) |
aa9147c9 | 325 | flags |= PT_SEIZED; |
4c44aaaf EB |
326 | rcu_read_lock(); |
327 | if (ns_capable(__task_cred(task)->user_ns, CAP_SYS_PTRACE)) | |
aa9147c9 | 328 | flags |= PT_PTRACE_CAP; |
4c44aaaf | 329 | rcu_read_unlock(); |
aa9147c9 | 330 | task->ptrace = flags; |
1da177e4 | 331 | |
1da177e4 | 332 | __ptrace_link(task, current); |
3544d72a TH |
333 | |
334 | /* SEIZE doesn't trap tracee on attach */ | |
335 | if (!seize) | |
336 | send_sig_info(SIGSTOP, SEND_SIG_FORCED, task); | |
b79b7ba9 | 337 | |
d79fdd6d TH |
338 | spin_lock(&task->sighand->siglock); |
339 | ||
340 | /* | |
73ddff2b | 341 | * If the task is already STOPPED, set JOBCTL_TRAP_STOP and |
d79fdd6d TH |
342 | * TRAPPING, and kick it so that it transits to TRACED. TRAPPING |
343 | * will be cleared if the child completes the transition or any | |
344 | * event which clears the group stop states happens. We'll wait | |
345 | * for the transition to complete before returning from this | |
346 | * function. | |
347 | * | |
348 | * This hides STOPPED -> RUNNING -> TRACED transition from the | |
349 | * attaching thread but a different thread in the same group can | |
350 | * still observe the transient RUNNING state. IOW, if another | |
351 | * thread's WNOHANG wait(2) on the stopped tracee races against | |
352 | * ATTACH, the wait(2) may fail due to the transient RUNNING. | |
353 | * | |
354 | * The following task_is_stopped() test is safe as both transitions | |
355 | * in and out of STOPPED are protected by siglock. | |
356 | */ | |
7dd3db54 | 357 | if (task_is_stopped(task) && |
73ddff2b | 358 | task_set_jobctl_pending(task, JOBCTL_TRAP_STOP | JOBCTL_TRAPPING)) |
910ffdb1 | 359 | signal_wake_up_state(task, __TASK_STOPPED); |
d79fdd6d TH |
360 | |
361 | spin_unlock(&task->sighand->siglock); | |
362 | ||
b79b7ba9 | 363 | retval = 0; |
4b105cbb ON |
364 | unlock_tasklist: |
365 | write_unlock_irq(&tasklist_lock); | |
366 | unlock_creds: | |
9b1bf12d | 367 | mutex_unlock(&task->signal->cred_guard_mutex); |
f5b40e36 | 368 | out: |
f701e5b7 | 369 | if (!retval) { |
62c124ff TH |
370 | wait_on_bit(&task->jobctl, JOBCTL_TRAPPING_BIT, |
371 | ptrace_trapping_sleep_fn, TASK_UNINTERRUPTIBLE); | |
f701e5b7 VZ |
372 | proc_ptrace_connector(task, PTRACE_ATTACH); |
373 | } | |
374 | ||
1da177e4 LT |
375 | return retval; |
376 | } | |
377 | ||
f2f0b00a ON |
378 | /** |
379 | * ptrace_traceme -- helper for PTRACE_TRACEME | |
380 | * | |
381 | * Performs checks and sets PT_PTRACED. | |
382 | * Should be used by all ptrace implementations for PTRACE_TRACEME. | |
383 | */ | |
e3e89cc5 | 384 | static int ptrace_traceme(void) |
f2f0b00a ON |
385 | { |
386 | int ret = -EPERM; | |
387 | ||
4b105cbb ON |
388 | write_lock_irq(&tasklist_lock); |
389 | /* Are we already being traced? */ | |
f2f0b00a | 390 | if (!current->ptrace) { |
f2f0b00a | 391 | ret = security_ptrace_traceme(current->parent); |
f2f0b00a ON |
392 | /* |
393 | * Check PF_EXITING to ensure ->real_parent has not passed | |
394 | * exit_ptrace(). Otherwise we don't report the error but | |
395 | * pretend ->real_parent untraces us right after return. | |
396 | */ | |
397 | if (!ret && !(current->real_parent->flags & PF_EXITING)) { | |
398 | current->ptrace = PT_PTRACED; | |
399 | __ptrace_link(current, current->real_parent); | |
400 | } | |
f2f0b00a | 401 | } |
4b105cbb ON |
402 | write_unlock_irq(&tasklist_lock); |
403 | ||
f2f0b00a ON |
404 | return ret; |
405 | } | |
406 | ||
39c626ae ON |
407 | /* |
408 | * Called with irqs disabled, returns true if childs should reap themselves. | |
409 | */ | |
410 | static int ignoring_children(struct sighand_struct *sigh) | |
411 | { | |
412 | int ret; | |
413 | spin_lock(&sigh->siglock); | |
414 | ret = (sigh->action[SIGCHLD-1].sa.sa_handler == SIG_IGN) || | |
415 | (sigh->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT); | |
416 | spin_unlock(&sigh->siglock); | |
417 | return ret; | |
418 | } | |
419 | ||
420 | /* | |
421 | * Called with tasklist_lock held for writing. | |
422 | * Unlink a traced task, and clean it up if it was a traced zombie. | |
423 | * Return true if it needs to be reaped with release_task(). | |
424 | * (We can't call release_task() here because we already hold tasklist_lock.) | |
425 | * | |
426 | * If it's a zombie, our attachedness prevented normal parent notification | |
427 | * or self-reaping. Do notification now if it would have happened earlier. | |
428 | * If it should reap itself, return true. | |
429 | * | |
a7f0765e ON |
430 | * If it's our own child, there is no notification to do. But if our normal |
431 | * children self-reap, then this child was prevented by ptrace and we must | |
432 | * reap it now, in that case we must also wake up sub-threads sleeping in | |
433 | * do_wait(). | |
39c626ae ON |
434 | */ |
435 | static bool __ptrace_detach(struct task_struct *tracer, struct task_struct *p) | |
436 | { | |
9843a1e9 ON |
437 | bool dead; |
438 | ||
39c626ae ON |
439 | __ptrace_unlink(p); |
440 | ||
9843a1e9 ON |
441 | if (p->exit_state != EXIT_ZOMBIE) |
442 | return false; | |
443 | ||
444 | dead = !thread_group_leader(p); | |
445 | ||
446 | if (!dead && thread_group_empty(p)) { | |
447 | if (!same_thread_group(p->real_parent, tracer)) | |
448 | dead = do_notify_parent(p, p->exit_signal); | |
449 | else if (ignoring_children(tracer->sighand)) { | |
450 | __wake_up_parent(p, tracer); | |
9843a1e9 | 451 | dead = true; |
39c626ae ON |
452 | } |
453 | } | |
9843a1e9 ON |
454 | /* Mark it as in the process of being reaped. */ |
455 | if (dead) | |
456 | p->exit_state = EXIT_DEAD; | |
457 | return dead; | |
39c626ae ON |
458 | } |
459 | ||
e3e89cc5 | 460 | static int ptrace_detach(struct task_struct *child, unsigned int data) |
1da177e4 | 461 | { |
39c626ae | 462 | bool dead = false; |
4576145c | 463 | |
7ed20e1a | 464 | if (!valid_signal(data)) |
5ecfbae0 | 465 | return -EIO; |
1da177e4 LT |
466 | |
467 | /* Architecture-specific hardware disable .. */ | |
468 | ptrace_disable(child); | |
7d941432 | 469 | clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); |
1da177e4 | 470 | |
95c3eb76 | 471 | write_lock_irq(&tasklist_lock); |
39c626ae ON |
472 | /* |
473 | * This child can be already killed. Make sure de_thread() or | |
474 | * our sub-thread doing do_wait() didn't do release_task() yet. | |
475 | */ | |
95c3eb76 ON |
476 | if (child->ptrace) { |
477 | child->exit_code = data; | |
4576145c | 478 | dead = __ptrace_detach(current, child); |
95c3eb76 | 479 | } |
1da177e4 LT |
480 | write_unlock_irq(&tasklist_lock); |
481 | ||
f701e5b7 | 482 | proc_ptrace_connector(child, PTRACE_DETACH); |
4576145c ON |
483 | if (unlikely(dead)) |
484 | release_task(child); | |
485 | ||
1da177e4 LT |
486 | return 0; |
487 | } | |
488 | ||
39c626ae | 489 | /* |
c7e49c14 ON |
490 | * Detach all tasks we were using ptrace on. Called with tasklist held |
491 | * for writing, and returns with it held too. But note it can release | |
492 | * and reacquire the lock. | |
39c626ae ON |
493 | */ |
494 | void exit_ptrace(struct task_struct *tracer) | |
c4b5ed25 NK |
495 | __releases(&tasklist_lock) |
496 | __acquires(&tasklist_lock) | |
39c626ae ON |
497 | { |
498 | struct task_struct *p, *n; | |
499 | LIST_HEAD(ptrace_dead); | |
500 | ||
c7e49c14 ON |
501 | if (likely(list_empty(&tracer->ptraced))) |
502 | return; | |
503 | ||
39c626ae | 504 | list_for_each_entry_safe(p, n, &tracer->ptraced, ptrace_entry) { |
992fb6e1 ON |
505 | if (unlikely(p->ptrace & PT_EXITKILL)) |
506 | send_sig_info(SIGKILL, SEND_SIG_FORCED, p); | |
507 | ||
39c626ae ON |
508 | if (__ptrace_detach(tracer, p)) |
509 | list_add(&p->ptrace_entry, &ptrace_dead); | |
510 | } | |
39c626ae | 511 | |
c7e49c14 | 512 | write_unlock_irq(&tasklist_lock); |
39c626ae ON |
513 | BUG_ON(!list_empty(&tracer->ptraced)); |
514 | ||
515 | list_for_each_entry_safe(p, n, &ptrace_dead, ptrace_entry) { | |
516 | list_del_init(&p->ptrace_entry); | |
517 | release_task(p); | |
518 | } | |
c7e49c14 ON |
519 | |
520 | write_lock_irq(&tasklist_lock); | |
39c626ae ON |
521 | } |
522 | ||
1da177e4 LT |
523 | int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len) |
524 | { | |
525 | int copied = 0; | |
526 | ||
527 | while (len > 0) { | |
528 | char buf[128]; | |
529 | int this_len, retval; | |
530 | ||
531 | this_len = (len > sizeof(buf)) ? sizeof(buf) : len; | |
532 | retval = access_process_vm(tsk, src, buf, this_len, 0); | |
533 | if (!retval) { | |
534 | if (copied) | |
535 | break; | |
536 | return -EIO; | |
537 | } | |
538 | if (copy_to_user(dst, buf, retval)) | |
539 | return -EFAULT; | |
540 | copied += retval; | |
541 | src += retval; | |
542 | dst += retval; | |
3a709703 | 543 | len -= retval; |
1da177e4 LT |
544 | } |
545 | return copied; | |
546 | } | |
547 | ||
548 | int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len) | |
549 | { | |
550 | int copied = 0; | |
551 | ||
552 | while (len > 0) { | |
553 | char buf[128]; | |
554 | int this_len, retval; | |
555 | ||
556 | this_len = (len > sizeof(buf)) ? sizeof(buf) : len; | |
557 | if (copy_from_user(buf, src, this_len)) | |
558 | return -EFAULT; | |
559 | retval = access_process_vm(tsk, dst, buf, this_len, 1); | |
560 | if (!retval) { | |
561 | if (copied) | |
562 | break; | |
563 | return -EIO; | |
564 | } | |
565 | copied += retval; | |
566 | src += retval; | |
567 | dst += retval; | |
3a709703 | 568 | len -= retval; |
1da177e4 LT |
569 | } |
570 | return copied; | |
571 | } | |
572 | ||
4abf9869 | 573 | static int ptrace_setoptions(struct task_struct *child, unsigned long data) |
1da177e4 | 574 | { |
86b6c1f3 DV |
575 | unsigned flags; |
576 | ||
8c5cf9e5 DV |
577 | if (data & ~(unsigned long)PTRACE_O_MASK) |
578 | return -EINVAL; | |
579 | ||
86b6c1f3 DV |
580 | /* Avoid intermediate state when all opts are cleared */ |
581 | flags = child->ptrace; | |
582 | flags &= ~(PTRACE_O_MASK << PT_OPT_FLAG_SHIFT); | |
583 | flags |= (data << PT_OPT_FLAG_SHIFT); | |
584 | child->ptrace = flags; | |
1da177e4 | 585 | |
8c5cf9e5 | 586 | return 0; |
1da177e4 LT |
587 | } |
588 | ||
e16b2781 | 589 | static int ptrace_getsiginfo(struct task_struct *child, siginfo_t *info) |
1da177e4 | 590 | { |
e4961254 | 591 | unsigned long flags; |
1da177e4 LT |
592 | int error = -ESRCH; |
593 | ||
e4961254 | 594 | if (lock_task_sighand(child, &flags)) { |
1da177e4 | 595 | error = -EINVAL; |
1da177e4 | 596 | if (likely(child->last_siginfo != NULL)) { |
e16b2781 | 597 | *info = *child->last_siginfo; |
1da177e4 LT |
598 | error = 0; |
599 | } | |
e4961254 | 600 | unlock_task_sighand(child, &flags); |
1da177e4 | 601 | } |
1da177e4 LT |
602 | return error; |
603 | } | |
604 | ||
e16b2781 | 605 | static int ptrace_setsiginfo(struct task_struct *child, const siginfo_t *info) |
1da177e4 | 606 | { |
e4961254 | 607 | unsigned long flags; |
1da177e4 LT |
608 | int error = -ESRCH; |
609 | ||
e4961254 | 610 | if (lock_task_sighand(child, &flags)) { |
1da177e4 | 611 | error = -EINVAL; |
1da177e4 | 612 | if (likely(child->last_siginfo != NULL)) { |
e16b2781 | 613 | *child->last_siginfo = *info; |
1da177e4 LT |
614 | error = 0; |
615 | } | |
e4961254 | 616 | unlock_task_sighand(child, &flags); |
1da177e4 | 617 | } |
1da177e4 LT |
618 | return error; |
619 | } | |
620 | ||
36df29d7 RM |
621 | |
622 | #ifdef PTRACE_SINGLESTEP | |
623 | #define is_singlestep(request) ((request) == PTRACE_SINGLESTEP) | |
624 | #else | |
625 | #define is_singlestep(request) 0 | |
626 | #endif | |
627 | ||
5b88abbf RM |
628 | #ifdef PTRACE_SINGLEBLOCK |
629 | #define is_singleblock(request) ((request) == PTRACE_SINGLEBLOCK) | |
630 | #else | |
631 | #define is_singleblock(request) 0 | |
632 | #endif | |
633 | ||
36df29d7 RM |
634 | #ifdef PTRACE_SYSEMU |
635 | #define is_sysemu_singlestep(request) ((request) == PTRACE_SYSEMU_SINGLESTEP) | |
636 | #else | |
637 | #define is_sysemu_singlestep(request) 0 | |
638 | #endif | |
639 | ||
4abf9869 NK |
640 | static int ptrace_resume(struct task_struct *child, long request, |
641 | unsigned long data) | |
36df29d7 RM |
642 | { |
643 | if (!valid_signal(data)) | |
644 | return -EIO; | |
645 | ||
646 | if (request == PTRACE_SYSCALL) | |
647 | set_tsk_thread_flag(child, TIF_SYSCALL_TRACE); | |
648 | else | |
649 | clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); | |
650 | ||
651 | #ifdef TIF_SYSCALL_EMU | |
652 | if (request == PTRACE_SYSEMU || request == PTRACE_SYSEMU_SINGLESTEP) | |
653 | set_tsk_thread_flag(child, TIF_SYSCALL_EMU); | |
654 | else | |
655 | clear_tsk_thread_flag(child, TIF_SYSCALL_EMU); | |
656 | #endif | |
657 | ||
5b88abbf RM |
658 | if (is_singleblock(request)) { |
659 | if (unlikely(!arch_has_block_step())) | |
660 | return -EIO; | |
661 | user_enable_block_step(child); | |
662 | } else if (is_singlestep(request) || is_sysemu_singlestep(request)) { | |
36df29d7 RM |
663 | if (unlikely(!arch_has_single_step())) |
664 | return -EIO; | |
665 | user_enable_single_step(child); | |
3a709703 | 666 | } else { |
36df29d7 | 667 | user_disable_single_step(child); |
3a709703 | 668 | } |
36df29d7 RM |
669 | |
670 | child->exit_code = data; | |
0666fb51 | 671 | wake_up_state(child, __TASK_TRACED); |
36df29d7 RM |
672 | |
673 | return 0; | |
674 | } | |
675 | ||
2225a122 SS |
676 | #ifdef CONFIG_HAVE_ARCH_TRACEHOOK |
677 | ||
678 | static const struct user_regset * | |
679 | find_regset(const struct user_regset_view *view, unsigned int type) | |
680 | { | |
681 | const struct user_regset *regset; | |
682 | int n; | |
683 | ||
684 | for (n = 0; n < view->n; ++n) { | |
685 | regset = view->regsets + n; | |
686 | if (regset->core_note_type == type) | |
687 | return regset; | |
688 | } | |
689 | ||
690 | return NULL; | |
691 | } | |
692 | ||
693 | static int ptrace_regset(struct task_struct *task, int req, unsigned int type, | |
694 | struct iovec *kiov) | |
695 | { | |
696 | const struct user_regset_view *view = task_user_regset_view(task); | |
697 | const struct user_regset *regset = find_regset(view, type); | |
698 | int regset_no; | |
699 | ||
700 | if (!regset || (kiov->iov_len % regset->size) != 0) | |
c6a0dd7e | 701 | return -EINVAL; |
2225a122 SS |
702 | |
703 | regset_no = regset - view->regsets; | |
704 | kiov->iov_len = min(kiov->iov_len, | |
705 | (__kernel_size_t) (regset->n * regset->size)); | |
706 | ||
707 | if (req == PTRACE_GETREGSET) | |
708 | return copy_regset_to_user(task, view, regset_no, 0, | |
709 | kiov->iov_len, kiov->iov_base); | |
710 | else | |
711 | return copy_regset_from_user(task, view, regset_no, 0, | |
712 | kiov->iov_len, kiov->iov_base); | |
713 | } | |
714 | ||
715 | #endif | |
716 | ||
1da177e4 | 717 | int ptrace_request(struct task_struct *child, long request, |
4abf9869 | 718 | unsigned long addr, unsigned long data) |
1da177e4 | 719 | { |
fca26f26 | 720 | bool seized = child->ptrace & PT_SEIZED; |
1da177e4 | 721 | int ret = -EIO; |
544b2c91 | 722 | siginfo_t siginfo, *si; |
9fed81dc NK |
723 | void __user *datavp = (void __user *) data; |
724 | unsigned long __user *datalp = datavp; | |
fca26f26 | 725 | unsigned long flags; |
1da177e4 LT |
726 | |
727 | switch (request) { | |
16c3e389 RM |
728 | case PTRACE_PEEKTEXT: |
729 | case PTRACE_PEEKDATA: | |
730 | return generic_ptrace_peekdata(child, addr, data); | |
731 | case PTRACE_POKETEXT: | |
732 | case PTRACE_POKEDATA: | |
733 | return generic_ptrace_pokedata(child, addr, data); | |
734 | ||
1da177e4 LT |
735 | #ifdef PTRACE_OLDSETOPTIONS |
736 | case PTRACE_OLDSETOPTIONS: | |
737 | #endif | |
738 | case PTRACE_SETOPTIONS: | |
739 | ret = ptrace_setoptions(child, data); | |
740 | break; | |
741 | case PTRACE_GETEVENTMSG: | |
9fed81dc | 742 | ret = put_user(child->ptrace_message, datalp); |
1da177e4 | 743 | break; |
e16b2781 | 744 | |
1da177e4 | 745 | case PTRACE_GETSIGINFO: |
e16b2781 RM |
746 | ret = ptrace_getsiginfo(child, &siginfo); |
747 | if (!ret) | |
9fed81dc | 748 | ret = copy_siginfo_to_user(datavp, &siginfo); |
1da177e4 | 749 | break; |
e16b2781 | 750 | |
1da177e4 | 751 | case PTRACE_SETSIGINFO: |
9fed81dc | 752 | if (copy_from_user(&siginfo, datavp, sizeof siginfo)) |
e16b2781 RM |
753 | ret = -EFAULT; |
754 | else | |
755 | ret = ptrace_setsiginfo(child, &siginfo); | |
1da177e4 | 756 | break; |
e16b2781 | 757 | |
fca26f26 TH |
758 | case PTRACE_INTERRUPT: |
759 | /* | |
760 | * Stop tracee without any side-effect on signal or job | |
761 | * control. At least one trap is guaranteed to happen | |
762 | * after this request. If @child is already trapped, the | |
763 | * current trap is not disturbed and another trap will | |
764 | * happen after the current trap is ended with PTRACE_CONT. | |
765 | * | |
766 | * The actual trap might not be PTRACE_EVENT_STOP trap but | |
767 | * the pending condition is cleared regardless. | |
768 | */ | |
769 | if (unlikely(!seized || !lock_task_sighand(child, &flags))) | |
770 | break; | |
771 | ||
544b2c91 TH |
772 | /* |
773 | * INTERRUPT doesn't disturb existing trap sans one | |
774 | * exception. If ptracer issued LISTEN for the current | |
775 | * STOP, this INTERRUPT should clear LISTEN and re-trap | |
776 | * tracee into STOP. | |
777 | */ | |
fca26f26 | 778 | if (likely(task_set_jobctl_pending(child, JOBCTL_TRAP_STOP))) |
910ffdb1 | 779 | ptrace_signal_wake_up(child, child->jobctl & JOBCTL_LISTENING); |
544b2c91 TH |
780 | |
781 | unlock_task_sighand(child, &flags); | |
782 | ret = 0; | |
783 | break; | |
784 | ||
785 | case PTRACE_LISTEN: | |
786 | /* | |
787 | * Listen for events. Tracee must be in STOP. It's not | |
788 | * resumed per-se but is not considered to be in TRACED by | |
789 | * wait(2) or ptrace(2). If an async event (e.g. group | |
790 | * stop state change) happens, tracee will enter STOP trap | |
791 | * again. Alternatively, ptracer can issue INTERRUPT to | |
792 | * finish listening and re-trap tracee into STOP. | |
793 | */ | |
794 | if (unlikely(!seized || !lock_task_sighand(child, &flags))) | |
795 | break; | |
796 | ||
797 | si = child->last_siginfo; | |
f9d81f61 ON |
798 | if (likely(si && (si->si_code >> 8) == PTRACE_EVENT_STOP)) { |
799 | child->jobctl |= JOBCTL_LISTENING; | |
800 | /* | |
801 | * If NOTIFY is set, it means event happened between | |
802 | * start of this trap and now. Trigger re-trap. | |
803 | */ | |
804 | if (child->jobctl & JOBCTL_TRAP_NOTIFY) | |
910ffdb1 | 805 | ptrace_signal_wake_up(child, true); |
f9d81f61 ON |
806 | ret = 0; |
807 | } | |
fca26f26 | 808 | unlock_task_sighand(child, &flags); |
fca26f26 TH |
809 | break; |
810 | ||
1bcf5482 AD |
811 | case PTRACE_DETACH: /* detach a process that was attached. */ |
812 | ret = ptrace_detach(child, data); | |
813 | break; | |
36df29d7 | 814 | |
9c1a1259 MF |
815 | #ifdef CONFIG_BINFMT_ELF_FDPIC |
816 | case PTRACE_GETFDPIC: { | |
e0129ef9 | 817 | struct mm_struct *mm = get_task_mm(child); |
9c1a1259 MF |
818 | unsigned long tmp = 0; |
819 | ||
e0129ef9 ON |
820 | ret = -ESRCH; |
821 | if (!mm) | |
822 | break; | |
823 | ||
9c1a1259 MF |
824 | switch (addr) { |
825 | case PTRACE_GETFDPIC_EXEC: | |
e0129ef9 | 826 | tmp = mm->context.exec_fdpic_loadmap; |
9c1a1259 MF |
827 | break; |
828 | case PTRACE_GETFDPIC_INTERP: | |
e0129ef9 | 829 | tmp = mm->context.interp_fdpic_loadmap; |
9c1a1259 MF |
830 | break; |
831 | default: | |
832 | break; | |
833 | } | |
e0129ef9 | 834 | mmput(mm); |
9c1a1259 | 835 | |
9fed81dc | 836 | ret = put_user(tmp, datalp); |
9c1a1259 MF |
837 | break; |
838 | } | |
839 | #endif | |
840 | ||
36df29d7 RM |
841 | #ifdef PTRACE_SINGLESTEP |
842 | case PTRACE_SINGLESTEP: | |
843 | #endif | |
5b88abbf RM |
844 | #ifdef PTRACE_SINGLEBLOCK |
845 | case PTRACE_SINGLEBLOCK: | |
846 | #endif | |
36df29d7 RM |
847 | #ifdef PTRACE_SYSEMU |
848 | case PTRACE_SYSEMU: | |
849 | case PTRACE_SYSEMU_SINGLESTEP: | |
850 | #endif | |
851 | case PTRACE_SYSCALL: | |
852 | case PTRACE_CONT: | |
853 | return ptrace_resume(child, request, data); | |
854 | ||
855 | case PTRACE_KILL: | |
856 | if (child->exit_state) /* already dead */ | |
857 | return 0; | |
858 | return ptrace_resume(child, request, SIGKILL); | |
859 | ||
2225a122 SS |
860 | #ifdef CONFIG_HAVE_ARCH_TRACEHOOK |
861 | case PTRACE_GETREGSET: | |
862 | case PTRACE_SETREGSET: | |
863 | { | |
864 | struct iovec kiov; | |
9fed81dc | 865 | struct iovec __user *uiov = datavp; |
2225a122 SS |
866 | |
867 | if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov))) | |
868 | return -EFAULT; | |
869 | ||
870 | if (__get_user(kiov.iov_base, &uiov->iov_base) || | |
871 | __get_user(kiov.iov_len, &uiov->iov_len)) | |
872 | return -EFAULT; | |
873 | ||
874 | ret = ptrace_regset(child, request, addr, &kiov); | |
875 | if (!ret) | |
876 | ret = __put_user(kiov.iov_len, &uiov->iov_len); | |
877 | break; | |
878 | } | |
879 | #endif | |
1da177e4 LT |
880 | default: |
881 | break; | |
882 | } | |
883 | ||
884 | return ret; | |
885 | } | |
481bed45 | 886 | |
8053bdd5 | 887 | static struct task_struct *ptrace_get_task_struct(pid_t pid) |
6b9c7ed8 CH |
888 | { |
889 | struct task_struct *child; | |
481bed45 | 890 | |
8053bdd5 | 891 | rcu_read_lock(); |
228ebcbe | 892 | child = find_task_by_vpid(pid); |
481bed45 CH |
893 | if (child) |
894 | get_task_struct(child); | |
8053bdd5 | 895 | rcu_read_unlock(); |
f400e198 | 896 | |
481bed45 | 897 | if (!child) |
6b9c7ed8 CH |
898 | return ERR_PTR(-ESRCH); |
899 | return child; | |
481bed45 CH |
900 | } |
901 | ||
0ac15559 CH |
902 | #ifndef arch_ptrace_attach |
903 | #define arch_ptrace_attach(child) do { } while (0) | |
904 | #endif | |
905 | ||
4abf9869 NK |
906 | SYSCALL_DEFINE4(ptrace, long, request, long, pid, unsigned long, addr, |
907 | unsigned long, data) | |
481bed45 CH |
908 | { |
909 | struct task_struct *child; | |
910 | long ret; | |
911 | ||
6b9c7ed8 CH |
912 | if (request == PTRACE_TRACEME) { |
913 | ret = ptrace_traceme(); | |
6ea6dd93 HS |
914 | if (!ret) |
915 | arch_ptrace_attach(current); | |
481bed45 | 916 | goto out; |
6b9c7ed8 CH |
917 | } |
918 | ||
919 | child = ptrace_get_task_struct(pid); | |
920 | if (IS_ERR(child)) { | |
921 | ret = PTR_ERR(child); | |
922 | goto out; | |
923 | } | |
481bed45 | 924 | |
3544d72a | 925 | if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) { |
aa9147c9 | 926 | ret = ptrace_attach(child, request, addr, data); |
0ac15559 CH |
927 | /* |
928 | * Some architectures need to do book-keeping after | |
929 | * a ptrace attach. | |
930 | */ | |
931 | if (!ret) | |
932 | arch_ptrace_attach(child); | |
005f18df | 933 | goto out_put_task_struct; |
481bed45 CH |
934 | } |
935 | ||
fca26f26 TH |
936 | ret = ptrace_check_attach(child, request == PTRACE_KILL || |
937 | request == PTRACE_INTERRUPT); | |
481bed45 CH |
938 | if (ret < 0) |
939 | goto out_put_task_struct; | |
940 | ||
941 | ret = arch_ptrace(child, request, addr, data); | |
9899d11f ON |
942 | if (ret || request != PTRACE_DETACH) |
943 | ptrace_unfreeze_traced(child); | |
481bed45 CH |
944 | |
945 | out_put_task_struct: | |
946 | put_task_struct(child); | |
947 | out: | |
481bed45 CH |
948 | return ret; |
949 | } | |
76647323 | 950 | |
4abf9869 NK |
951 | int generic_ptrace_peekdata(struct task_struct *tsk, unsigned long addr, |
952 | unsigned long data) | |
76647323 AD |
953 | { |
954 | unsigned long tmp; | |
955 | int copied; | |
956 | ||
957 | copied = access_process_vm(tsk, addr, &tmp, sizeof(tmp), 0); | |
958 | if (copied != sizeof(tmp)) | |
959 | return -EIO; | |
960 | return put_user(tmp, (unsigned long __user *)data); | |
961 | } | |
f284ce72 | 962 | |
4abf9869 NK |
963 | int generic_ptrace_pokedata(struct task_struct *tsk, unsigned long addr, |
964 | unsigned long data) | |
f284ce72 AD |
965 | { |
966 | int copied; | |
967 | ||
968 | copied = access_process_vm(tsk, addr, &data, sizeof(data), 1); | |
969 | return (copied == sizeof(data)) ? 0 : -EIO; | |
970 | } | |
032d82d9 | 971 | |
96b8936a | 972 | #if defined CONFIG_COMPAT |
032d82d9 RM |
973 | #include <linux/compat.h> |
974 | ||
975 | int compat_ptrace_request(struct task_struct *child, compat_long_t request, | |
976 | compat_ulong_t addr, compat_ulong_t data) | |
977 | { | |
978 | compat_ulong_t __user *datap = compat_ptr(data); | |
979 | compat_ulong_t word; | |
e16b2781 | 980 | siginfo_t siginfo; |
032d82d9 RM |
981 | int ret; |
982 | ||
983 | switch (request) { | |
984 | case PTRACE_PEEKTEXT: | |
985 | case PTRACE_PEEKDATA: | |
986 | ret = access_process_vm(child, addr, &word, sizeof(word), 0); | |
987 | if (ret != sizeof(word)) | |
988 | ret = -EIO; | |
989 | else | |
990 | ret = put_user(word, datap); | |
991 | break; | |
992 | ||
993 | case PTRACE_POKETEXT: | |
994 | case PTRACE_POKEDATA: | |
995 | ret = access_process_vm(child, addr, &data, sizeof(data), 1); | |
996 | ret = (ret != sizeof(data) ? -EIO : 0); | |
997 | break; | |
998 | ||
999 | case PTRACE_GETEVENTMSG: | |
1000 | ret = put_user((compat_ulong_t) child->ptrace_message, datap); | |
1001 | break; | |
1002 | ||
e16b2781 RM |
1003 | case PTRACE_GETSIGINFO: |
1004 | ret = ptrace_getsiginfo(child, &siginfo); | |
1005 | if (!ret) | |
1006 | ret = copy_siginfo_to_user32( | |
1007 | (struct compat_siginfo __user *) datap, | |
1008 | &siginfo); | |
1009 | break; | |
1010 | ||
1011 | case PTRACE_SETSIGINFO: | |
1012 | memset(&siginfo, 0, sizeof siginfo); | |
1013 | if (copy_siginfo_from_user32( | |
1014 | &siginfo, (struct compat_siginfo __user *) datap)) | |
1015 | ret = -EFAULT; | |
1016 | else | |
1017 | ret = ptrace_setsiginfo(child, &siginfo); | |
1018 | break; | |
2225a122 SS |
1019 | #ifdef CONFIG_HAVE_ARCH_TRACEHOOK |
1020 | case PTRACE_GETREGSET: | |
1021 | case PTRACE_SETREGSET: | |
1022 | { | |
1023 | struct iovec kiov; | |
1024 | struct compat_iovec __user *uiov = | |
1025 | (struct compat_iovec __user *) datap; | |
1026 | compat_uptr_t ptr; | |
1027 | compat_size_t len; | |
1028 | ||
1029 | if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov))) | |
1030 | return -EFAULT; | |
1031 | ||
1032 | if (__get_user(ptr, &uiov->iov_base) || | |
1033 | __get_user(len, &uiov->iov_len)) | |
1034 | return -EFAULT; | |
1035 | ||
1036 | kiov.iov_base = compat_ptr(ptr); | |
1037 | kiov.iov_len = len; | |
1038 | ||
1039 | ret = ptrace_regset(child, request, addr, &kiov); | |
1040 | if (!ret) | |
1041 | ret = __put_user(kiov.iov_len, &uiov->iov_len); | |
1042 | break; | |
1043 | } | |
1044 | #endif | |
e16b2781 | 1045 | |
032d82d9 RM |
1046 | default: |
1047 | ret = ptrace_request(child, request, addr, data); | |
1048 | } | |
1049 | ||
1050 | return ret; | |
1051 | } | |
c269f196 | 1052 | |
c269f196 RM |
1053 | asmlinkage long compat_sys_ptrace(compat_long_t request, compat_long_t pid, |
1054 | compat_long_t addr, compat_long_t data) | |
1055 | { | |
1056 | struct task_struct *child; | |
1057 | long ret; | |
1058 | ||
c269f196 RM |
1059 | if (request == PTRACE_TRACEME) { |
1060 | ret = ptrace_traceme(); | |
1061 | goto out; | |
1062 | } | |
1063 | ||
1064 | child = ptrace_get_task_struct(pid); | |
1065 | if (IS_ERR(child)) { | |
1066 | ret = PTR_ERR(child); | |
1067 | goto out; | |
1068 | } | |
1069 | ||
3544d72a | 1070 | if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) { |
aa9147c9 | 1071 | ret = ptrace_attach(child, request, addr, data); |
c269f196 RM |
1072 | /* |
1073 | * Some architectures need to do book-keeping after | |
1074 | * a ptrace attach. | |
1075 | */ | |
1076 | if (!ret) | |
1077 | arch_ptrace_attach(child); | |
1078 | goto out_put_task_struct; | |
1079 | } | |
1080 | ||
fca26f26 TH |
1081 | ret = ptrace_check_attach(child, request == PTRACE_KILL || |
1082 | request == PTRACE_INTERRUPT); | |
9899d11f | 1083 | if (!ret) { |
c269f196 | 1084 | ret = compat_arch_ptrace(child, request, addr, data); |
9899d11f ON |
1085 | if (ret || request != PTRACE_DETACH) |
1086 | ptrace_unfreeze_traced(child); | |
1087 | } | |
c269f196 RM |
1088 | |
1089 | out_put_task_struct: | |
1090 | put_task_struct(child); | |
1091 | out: | |
c269f196 RM |
1092 | return ret; |
1093 | } | |
96b8936a | 1094 | #endif /* CONFIG_COMPAT */ |
bf26c018 FW |
1095 | |
1096 | #ifdef CONFIG_HAVE_HW_BREAKPOINT | |
1097 | int ptrace_get_breakpoints(struct task_struct *tsk) | |
1098 | { | |
1099 | if (atomic_inc_not_zero(&tsk->ptrace_bp_refcnt)) | |
1100 | return 0; | |
1101 | ||
1102 | return -1; | |
1103 | } | |
1104 | ||
1105 | void ptrace_put_breakpoints(struct task_struct *tsk) | |
1106 | { | |
1107 | if (atomic_dec_and_test(&tsk->ptrace_bp_refcnt)) | |
1108 | flush_ptrace_hw_breakpoint(tsk); | |
1109 | } | |
1110 | #endif /* CONFIG_HAVE_HW_BREAKPOINT */ |