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Commit | Line | Data |
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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> |
a27bb332 | 20 | #include <linux/uio.h> |
a5cb013d | 21 | #include <linux/audit.h> |
b488893a | 22 | #include <linux/pid_namespace.h> |
f17d30a8 | 23 | #include <linux/syscalls.h> |
3a709703 | 24 | #include <linux/uaccess.h> |
2225a122 | 25 | #include <linux/regset.h> |
bf26c018 | 26 | #include <linux/hw_breakpoint.h> |
f701e5b7 | 27 | #include <linux/cn_proc.h> |
84c751bd | 28 | #include <linux/compat.h> |
1da177e4 | 29 | |
bf53de90 | 30 | |
1da177e4 LT |
31 | /* |
32 | * ptrace a task: make the debugger its new parent and | |
33 | * move it to the ptrace list. | |
34 | * | |
35 | * Must be called with the tasklist lock write-held. | |
36 | */ | |
36c8b586 | 37 | void __ptrace_link(struct task_struct *child, struct task_struct *new_parent) |
1da177e4 | 38 | { |
f470021a RM |
39 | BUG_ON(!list_empty(&child->ptrace_entry)); |
40 | list_add(&child->ptrace_entry, &new_parent->ptraced); | |
1da177e4 | 41 | child->parent = new_parent; |
1da177e4 | 42 | } |
3a709703 | 43 | |
e3bd058f TH |
44 | /** |
45 | * __ptrace_unlink - unlink ptracee and restore its execution state | |
46 | * @child: ptracee to be unlinked | |
1da177e4 | 47 | * |
0e9f0a4a TH |
48 | * Remove @child from the ptrace list, move it back to the original parent, |
49 | * and restore the execution state so that it conforms to the group stop | |
50 | * state. | |
51 | * | |
52 | * Unlinking can happen via two paths - explicit PTRACE_DETACH or ptracer | |
53 | * exiting. For PTRACE_DETACH, unless the ptracee has been killed between | |
54 | * ptrace_check_attach() and here, it's guaranteed to be in TASK_TRACED. | |
55 | * If the ptracer is exiting, the ptracee can be in any state. | |
56 | * | |
57 | * After detach, the ptracee should be in a state which conforms to the | |
58 | * group stop. If the group is stopped or in the process of stopping, the | |
59 | * ptracee should be put into TASK_STOPPED; otherwise, it should be woken | |
60 | * up from TASK_TRACED. | |
61 | * | |
62 | * If the ptracee is in TASK_TRACED and needs to be moved to TASK_STOPPED, | |
63 | * it goes through TRACED -> RUNNING -> STOPPED transition which is similar | |
64 | * to but in the opposite direction of what happens while attaching to a | |
65 | * stopped task. However, in this direction, the intermediate RUNNING | |
66 | * state is not hidden even from the current ptracer and if it immediately | |
67 | * re-attaches and performs a WNOHANG wait(2), it may fail. | |
e3bd058f TH |
68 | * |
69 | * CONTEXT: | |
70 | * write_lock_irq(tasklist_lock) | |
1da177e4 | 71 | */ |
36c8b586 | 72 | void __ptrace_unlink(struct task_struct *child) |
1da177e4 | 73 | { |
5ecfbae0 ON |
74 | BUG_ON(!child->ptrace); |
75 | ||
1da177e4 | 76 | child->ptrace = 0; |
f470021a RM |
77 | child->parent = child->real_parent; |
78 | list_del_init(&child->ptrace_entry); | |
1da177e4 | 79 | |
1da177e4 | 80 | spin_lock(&child->sighand->siglock); |
0e9f0a4a | 81 | |
73ddff2b TH |
82 | /* |
83 | * Clear all pending traps and TRAPPING. TRAPPING should be | |
84 | * cleared regardless of JOBCTL_STOP_PENDING. Do it explicitly. | |
85 | */ | |
86 | task_clear_jobctl_pending(child, JOBCTL_TRAP_MASK); | |
87 | task_clear_jobctl_trapping(child); | |
88 | ||
0e9f0a4a | 89 | /* |
a8f072c1 | 90 | * Reinstate JOBCTL_STOP_PENDING if group stop is in effect and |
0e9f0a4a TH |
91 | * @child isn't dead. |
92 | */ | |
93 | if (!(child->flags & PF_EXITING) && | |
94 | (child->signal->flags & SIGNAL_STOP_STOPPED || | |
8a88951b | 95 | child->signal->group_stop_count)) { |
a8f072c1 | 96 | child->jobctl |= JOBCTL_STOP_PENDING; |
0e9f0a4a | 97 | |
8a88951b ON |
98 | /* |
99 | * This is only possible if this thread was cloned by the | |
100 | * traced task running in the stopped group, set the signal | |
101 | * for the future reports. | |
102 | * FIXME: we should change ptrace_init_task() to handle this | |
103 | * case. | |
104 | */ | |
105 | if (!(child->jobctl & JOBCTL_STOP_SIGMASK)) | |
106 | child->jobctl |= SIGSTOP; | |
107 | } | |
108 | ||
0e9f0a4a TH |
109 | /* |
110 | * If transition to TASK_STOPPED is pending or in TASK_TRACED, kick | |
111 | * @child in the butt. Note that @resume should be used iff @child | |
112 | * is in TASK_TRACED; otherwise, we might unduly disrupt | |
113 | * TASK_KILLABLE sleeps. | |
114 | */ | |
a8f072c1 | 115 | if (child->jobctl & JOBCTL_STOP_PENDING || task_is_traced(child)) |
910ffdb1 | 116 | ptrace_signal_wake_up(child, true); |
0e9f0a4a | 117 | |
1da177e4 | 118 | spin_unlock(&child->sighand->siglock); |
1da177e4 LT |
119 | } |
120 | ||
9899d11f ON |
121 | /* Ensure that nothing can wake it up, even SIGKILL */ |
122 | static bool ptrace_freeze_traced(struct task_struct *task) | |
123 | { | |
124 | bool ret = false; | |
125 | ||
126 | /* Lockless, nobody but us can set this flag */ | |
127 | if (task->jobctl & JOBCTL_LISTENING) | |
128 | return ret; | |
129 | ||
130 | spin_lock_irq(&task->sighand->siglock); | |
131 | if (task_is_traced(task) && !__fatal_signal_pending(task)) { | |
132 | task->state = __TASK_TRACED; | |
133 | ret = true; | |
134 | } | |
135 | spin_unlock_irq(&task->sighand->siglock); | |
136 | ||
137 | return ret; | |
138 | } | |
139 | ||
140 | static void ptrace_unfreeze_traced(struct task_struct *task) | |
141 | { | |
142 | if (task->state != __TASK_TRACED) | |
143 | return; | |
144 | ||
145 | WARN_ON(!task->ptrace || task->parent != current); | |
146 | ||
147 | spin_lock_irq(&task->sighand->siglock); | |
148 | if (__fatal_signal_pending(task)) | |
149 | wake_up_state(task, __TASK_TRACED); | |
150 | else | |
151 | task->state = TASK_TRACED; | |
152 | spin_unlock_irq(&task->sighand->siglock); | |
153 | } | |
154 | ||
755e276b TH |
155 | /** |
156 | * ptrace_check_attach - check whether ptracee is ready for ptrace operation | |
157 | * @child: ptracee to check for | |
158 | * @ignore_state: don't check whether @child is currently %TASK_TRACED | |
159 | * | |
160 | * Check whether @child is being ptraced by %current and ready for further | |
161 | * ptrace operations. If @ignore_state is %false, @child also should be in | |
162 | * %TASK_TRACED state and on return the child is guaranteed to be traced | |
163 | * and not executing. If @ignore_state is %true, @child can be in any | |
164 | * state. | |
165 | * | |
166 | * CONTEXT: | |
167 | * Grabs and releases tasklist_lock and @child->sighand->siglock. | |
168 | * | |
169 | * RETURNS: | |
170 | * 0 on success, -ESRCH if %child is not ready. | |
1da177e4 | 171 | */ |
edea0d03 | 172 | static int ptrace_check_attach(struct task_struct *child, bool ignore_state) |
1da177e4 LT |
173 | { |
174 | int ret = -ESRCH; | |
175 | ||
176 | /* | |
177 | * We take the read lock around doing both checks to close a | |
178 | * possible race where someone else was tracing our child and | |
179 | * detached between these two checks. After this locked check, | |
180 | * we are sure that this is our traced child and that can only | |
181 | * be changed by us so it's not changing right after this. | |
182 | */ | |
183 | read_lock(&tasklist_lock); | |
9899d11f ON |
184 | if (child->ptrace && child->parent == current) { |
185 | WARN_ON(child->state == __TASK_TRACED); | |
c0c0b649 ON |
186 | /* |
187 | * child->sighand can't be NULL, release_task() | |
188 | * does ptrace_unlink() before __exit_signal(). | |
189 | */ | |
9899d11f | 190 | if (ignore_state || ptrace_freeze_traced(child)) |
321fb561 | 191 | ret = 0; |
1da177e4 LT |
192 | } |
193 | read_unlock(&tasklist_lock); | |
194 | ||
9899d11f ON |
195 | if (!ret && !ignore_state) { |
196 | if (!wait_task_inactive(child, __TASK_TRACED)) { | |
197 | /* | |
198 | * This can only happen if may_ptrace_stop() fails and | |
199 | * ptrace_stop() changes ->state back to TASK_RUNNING, | |
200 | * so we should not worry about leaking __TASK_TRACED. | |
201 | */ | |
202 | WARN_ON(child->state == __TASK_TRACED); | |
203 | ret = -ESRCH; | |
204 | } | |
205 | } | |
1da177e4 | 206 | |
1da177e4 LT |
207 | return ret; |
208 | } | |
209 | ||
69f594a3 EP |
210 | static int ptrace_has_cap(struct user_namespace *ns, unsigned int mode) |
211 | { | |
212 | if (mode & PTRACE_MODE_NOAUDIT) | |
213 | return has_ns_capability_noaudit(current, ns, CAP_SYS_PTRACE); | |
214 | else | |
215 | return has_ns_capability(current, ns, CAP_SYS_PTRACE); | |
216 | } | |
217 | ||
9f99798f TH |
218 | /* Returns 0 on success, -errno on denial. */ |
219 | static int __ptrace_may_access(struct task_struct *task, unsigned int mode) | |
ab8d11be | 220 | { |
c69e8d9c | 221 | const struct cred *cred = current_cred(), *tcred; |
b6dff3ec | 222 | |
df26c40e EB |
223 | /* May we inspect the given task? |
224 | * This check is used both for attaching with ptrace | |
225 | * and for allowing access to sensitive information in /proc. | |
226 | * | |
227 | * ptrace_attach denies several cases that /proc allows | |
228 | * because setting up the necessary parent/child relationship | |
229 | * or halting the specified task is impossible. | |
230 | */ | |
231 | int dumpable = 0; | |
232 | /* Don't let security modules deny introspection */ | |
73af963f | 233 | if (same_thread_group(task, current)) |
df26c40e | 234 | return 0; |
c69e8d9c DH |
235 | rcu_read_lock(); |
236 | tcred = __task_cred(task); | |
5af66203 EB |
237 | if (uid_eq(cred->uid, tcred->euid) && |
238 | uid_eq(cred->uid, tcred->suid) && | |
239 | uid_eq(cred->uid, tcred->uid) && | |
240 | gid_eq(cred->gid, tcred->egid) && | |
241 | gid_eq(cred->gid, tcred->sgid) && | |
242 | gid_eq(cred->gid, tcred->gid)) | |
8409cca7 | 243 | goto ok; |
c4a4d603 | 244 | if (ptrace_has_cap(tcred->user_ns, mode)) |
8409cca7 SH |
245 | goto ok; |
246 | rcu_read_unlock(); | |
247 | return -EPERM; | |
248 | ok: | |
c69e8d9c | 249 | rcu_read_unlock(); |
ab8d11be | 250 | smp_rmb(); |
df26c40e | 251 | if (task->mm) |
6c5d5238 | 252 | dumpable = get_dumpable(task->mm); |
4c44aaaf | 253 | rcu_read_lock(); |
d049f74f KC |
254 | if (dumpable != SUID_DUMP_USER && |
255 | !ptrace_has_cap(__task_cred(task)->user_ns, mode)) { | |
4c44aaaf | 256 | rcu_read_unlock(); |
ab8d11be | 257 | return -EPERM; |
4c44aaaf EB |
258 | } |
259 | rcu_read_unlock(); | |
ab8d11be | 260 | |
9e48858f | 261 | return security_ptrace_access_check(task, mode); |
ab8d11be MS |
262 | } |
263 | ||
006ebb40 | 264 | bool ptrace_may_access(struct task_struct *task, unsigned int mode) |
ab8d11be MS |
265 | { |
266 | int err; | |
267 | task_lock(task); | |
006ebb40 | 268 | err = __ptrace_may_access(task, mode); |
ab8d11be | 269 | task_unlock(task); |
3a709703 | 270 | return !err; |
ab8d11be MS |
271 | } |
272 | ||
3544d72a | 273 | static int ptrace_attach(struct task_struct *task, long request, |
aa9147c9 | 274 | unsigned long addr, |
3544d72a | 275 | unsigned long flags) |
1da177e4 | 276 | { |
3544d72a | 277 | bool seize = (request == PTRACE_SEIZE); |
1da177e4 | 278 | int retval; |
f5b40e36 | 279 | |
3544d72a | 280 | retval = -EIO; |
aa9147c9 DV |
281 | if (seize) { |
282 | if (addr != 0) | |
283 | goto out; | |
aa9147c9 DV |
284 | if (flags & ~(unsigned long)PTRACE_O_MASK) |
285 | goto out; | |
286 | flags = PT_PTRACED | PT_SEIZED | (flags << PT_OPT_FLAG_SHIFT); | |
287 | } else { | |
288 | flags = PT_PTRACED; | |
289 | } | |
3544d72a | 290 | |
a5cb013d AV |
291 | audit_ptrace(task); |
292 | ||
1da177e4 | 293 | retval = -EPERM; |
b79b7ba9 ON |
294 | if (unlikely(task->flags & PF_KTHREAD)) |
295 | goto out; | |
bac0abd6 | 296 | if (same_thread_group(task, current)) |
f5b40e36 LT |
297 | goto out; |
298 | ||
f2f0b00a ON |
299 | /* |
300 | * Protect exec's credential calculations against our interference; | |
86b6c1f3 | 301 | * SUID, SGID and LSM creds get determined differently |
5e751e99 | 302 | * under ptrace. |
d84f4f99 | 303 | */ |
793285fc | 304 | retval = -ERESTARTNOINTR; |
9b1bf12d | 305 | if (mutex_lock_interruptible(&task->signal->cred_guard_mutex)) |
d84f4f99 | 306 | goto out; |
f5b40e36 | 307 | |
4b105cbb | 308 | task_lock(task); |
006ebb40 | 309 | retval = __ptrace_may_access(task, PTRACE_MODE_ATTACH); |
4b105cbb | 310 | task_unlock(task); |
1da177e4 | 311 | if (retval) |
4b105cbb | 312 | goto unlock_creds; |
1da177e4 | 313 | |
4b105cbb | 314 | write_lock_irq(&tasklist_lock); |
b79b7ba9 ON |
315 | retval = -EPERM; |
316 | if (unlikely(task->exit_state)) | |
4b105cbb | 317 | goto unlock_tasklist; |
f2f0b00a | 318 | if (task->ptrace) |
4b105cbb | 319 | goto unlock_tasklist; |
b79b7ba9 | 320 | |
3544d72a | 321 | if (seize) |
aa9147c9 | 322 | flags |= PT_SEIZED; |
4c44aaaf EB |
323 | rcu_read_lock(); |
324 | if (ns_capable(__task_cred(task)->user_ns, CAP_SYS_PTRACE)) | |
aa9147c9 | 325 | flags |= PT_PTRACE_CAP; |
4c44aaaf | 326 | rcu_read_unlock(); |
aa9147c9 | 327 | task->ptrace = flags; |
1da177e4 | 328 | |
1da177e4 | 329 | __ptrace_link(task, current); |
3544d72a TH |
330 | |
331 | /* SEIZE doesn't trap tracee on attach */ | |
332 | if (!seize) | |
333 | send_sig_info(SIGSTOP, SEND_SIG_FORCED, task); | |
b79b7ba9 | 334 | |
d79fdd6d TH |
335 | spin_lock(&task->sighand->siglock); |
336 | ||
337 | /* | |
73ddff2b | 338 | * If the task is already STOPPED, set JOBCTL_TRAP_STOP and |
d79fdd6d TH |
339 | * TRAPPING, and kick it so that it transits to TRACED. TRAPPING |
340 | * will be cleared if the child completes the transition or any | |
341 | * event which clears the group stop states happens. We'll wait | |
342 | * for the transition to complete before returning from this | |
343 | * function. | |
344 | * | |
345 | * This hides STOPPED -> RUNNING -> TRACED transition from the | |
346 | * attaching thread but a different thread in the same group can | |
347 | * still observe the transient RUNNING state. IOW, if another | |
348 | * thread's WNOHANG wait(2) on the stopped tracee races against | |
349 | * ATTACH, the wait(2) may fail due to the transient RUNNING. | |
350 | * | |
351 | * The following task_is_stopped() test is safe as both transitions | |
352 | * in and out of STOPPED are protected by siglock. | |
353 | */ | |
7dd3db54 | 354 | if (task_is_stopped(task) && |
73ddff2b | 355 | task_set_jobctl_pending(task, JOBCTL_TRAP_STOP | JOBCTL_TRAPPING)) |
910ffdb1 | 356 | signal_wake_up_state(task, __TASK_STOPPED); |
d79fdd6d TH |
357 | |
358 | spin_unlock(&task->sighand->siglock); | |
359 | ||
b79b7ba9 | 360 | retval = 0; |
4b105cbb ON |
361 | unlock_tasklist: |
362 | write_unlock_irq(&tasklist_lock); | |
363 | unlock_creds: | |
9b1bf12d | 364 | mutex_unlock(&task->signal->cred_guard_mutex); |
f5b40e36 | 365 | out: |
f701e5b7 | 366 | if (!retval) { |
62c124ff | 367 | wait_on_bit(&task->jobctl, JOBCTL_TRAPPING_BIT, |
74316201 | 368 | TASK_UNINTERRUPTIBLE); |
f701e5b7 VZ |
369 | proc_ptrace_connector(task, PTRACE_ATTACH); |
370 | } | |
371 | ||
1da177e4 LT |
372 | return retval; |
373 | } | |
374 | ||
f2f0b00a ON |
375 | /** |
376 | * ptrace_traceme -- helper for PTRACE_TRACEME | |
377 | * | |
378 | * Performs checks and sets PT_PTRACED. | |
379 | * Should be used by all ptrace implementations for PTRACE_TRACEME. | |
380 | */ | |
e3e89cc5 | 381 | static int ptrace_traceme(void) |
f2f0b00a ON |
382 | { |
383 | int ret = -EPERM; | |
384 | ||
4b105cbb ON |
385 | write_lock_irq(&tasklist_lock); |
386 | /* Are we already being traced? */ | |
f2f0b00a | 387 | if (!current->ptrace) { |
f2f0b00a | 388 | ret = security_ptrace_traceme(current->parent); |
f2f0b00a ON |
389 | /* |
390 | * Check PF_EXITING to ensure ->real_parent has not passed | |
391 | * exit_ptrace(). Otherwise we don't report the error but | |
392 | * pretend ->real_parent untraces us right after return. | |
393 | */ | |
394 | if (!ret && !(current->real_parent->flags & PF_EXITING)) { | |
395 | current->ptrace = PT_PTRACED; | |
396 | __ptrace_link(current, current->real_parent); | |
397 | } | |
f2f0b00a | 398 | } |
4b105cbb ON |
399 | write_unlock_irq(&tasklist_lock); |
400 | ||
f2f0b00a ON |
401 | return ret; |
402 | } | |
403 | ||
39c626ae ON |
404 | /* |
405 | * Called with irqs disabled, returns true if childs should reap themselves. | |
406 | */ | |
407 | static int ignoring_children(struct sighand_struct *sigh) | |
408 | { | |
409 | int ret; | |
410 | spin_lock(&sigh->siglock); | |
411 | ret = (sigh->action[SIGCHLD-1].sa.sa_handler == SIG_IGN) || | |
412 | (sigh->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT); | |
413 | spin_unlock(&sigh->siglock); | |
414 | return ret; | |
415 | } | |
416 | ||
417 | /* | |
418 | * Called with tasklist_lock held for writing. | |
419 | * Unlink a traced task, and clean it up if it was a traced zombie. | |
420 | * Return true if it needs to be reaped with release_task(). | |
421 | * (We can't call release_task() here because we already hold tasklist_lock.) | |
422 | * | |
423 | * If it's a zombie, our attachedness prevented normal parent notification | |
424 | * or self-reaping. Do notification now if it would have happened earlier. | |
425 | * If it should reap itself, return true. | |
426 | * | |
a7f0765e ON |
427 | * If it's our own child, there is no notification to do. But if our normal |
428 | * children self-reap, then this child was prevented by ptrace and we must | |
429 | * reap it now, in that case we must also wake up sub-threads sleeping in | |
430 | * do_wait(). | |
39c626ae ON |
431 | */ |
432 | static bool __ptrace_detach(struct task_struct *tracer, struct task_struct *p) | |
433 | { | |
9843a1e9 ON |
434 | bool dead; |
435 | ||
39c626ae ON |
436 | __ptrace_unlink(p); |
437 | ||
9843a1e9 ON |
438 | if (p->exit_state != EXIT_ZOMBIE) |
439 | return false; | |
440 | ||
441 | dead = !thread_group_leader(p); | |
442 | ||
443 | if (!dead && thread_group_empty(p)) { | |
444 | if (!same_thread_group(p->real_parent, tracer)) | |
445 | dead = do_notify_parent(p, p->exit_signal); | |
446 | else if (ignoring_children(tracer->sighand)) { | |
447 | __wake_up_parent(p, tracer); | |
9843a1e9 | 448 | dead = true; |
39c626ae ON |
449 | } |
450 | } | |
9843a1e9 ON |
451 | /* Mark it as in the process of being reaped. */ |
452 | if (dead) | |
453 | p->exit_state = EXIT_DEAD; | |
454 | return dead; | |
39c626ae ON |
455 | } |
456 | ||
e3e89cc5 | 457 | static int ptrace_detach(struct task_struct *child, unsigned int data) |
1da177e4 | 458 | { |
7ed20e1a | 459 | if (!valid_signal(data)) |
5ecfbae0 | 460 | return -EIO; |
1da177e4 LT |
461 | |
462 | /* Architecture-specific hardware disable .. */ | |
463 | ptrace_disable(child); | |
7d941432 | 464 | clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); |
1da177e4 | 465 | |
95c3eb76 | 466 | write_lock_irq(&tasklist_lock); |
39c626ae | 467 | /* |
64a4096c ON |
468 | * We rely on ptrace_freeze_traced(). It can't be killed and |
469 | * untraced by another thread, it can't be a zombie. | |
39c626ae | 470 | */ |
64a4096c ON |
471 | WARN_ON(!child->ptrace || child->exit_state); |
472 | /* | |
473 | * tasklist_lock avoids the race with wait_task_stopped(), see | |
474 | * the comment in ptrace_resume(). | |
475 | */ | |
476 | child->exit_code = data; | |
477 | __ptrace_detach(current, child); | |
1da177e4 LT |
478 | write_unlock_irq(&tasklist_lock); |
479 | ||
f701e5b7 | 480 | proc_ptrace_connector(child, PTRACE_DETACH); |
4576145c | 481 | |
1da177e4 LT |
482 | return 0; |
483 | } | |
484 | ||
39c626ae | 485 | /* |
c7e49c14 | 486 | * Detach all tasks we were using ptrace on. Called with tasklist held |
7c8bd232 | 487 | * for writing. |
39c626ae | 488 | */ |
7c8bd232 | 489 | void exit_ptrace(struct task_struct *tracer, struct list_head *dead) |
39c626ae ON |
490 | { |
491 | struct task_struct *p, *n; | |
c7e49c14 | 492 | |
39c626ae | 493 | list_for_each_entry_safe(p, n, &tracer->ptraced, ptrace_entry) { |
992fb6e1 ON |
494 | if (unlikely(p->ptrace & PT_EXITKILL)) |
495 | send_sig_info(SIGKILL, SEND_SIG_FORCED, p); | |
496 | ||
39c626ae | 497 | if (__ptrace_detach(tracer, p)) |
7c8bd232 | 498 | list_add(&p->ptrace_entry, dead); |
39c626ae ON |
499 | } |
500 | } | |
501 | ||
1da177e4 LT |
502 | int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len) |
503 | { | |
504 | int copied = 0; | |
505 | ||
506 | while (len > 0) { | |
507 | char buf[128]; | |
508 | int this_len, retval; | |
509 | ||
510 | this_len = (len > sizeof(buf)) ? sizeof(buf) : len; | |
511 | retval = access_process_vm(tsk, src, buf, this_len, 0); | |
512 | if (!retval) { | |
513 | if (copied) | |
514 | break; | |
515 | return -EIO; | |
516 | } | |
517 | if (copy_to_user(dst, buf, retval)) | |
518 | return -EFAULT; | |
519 | copied += retval; | |
520 | src += retval; | |
521 | dst += retval; | |
3a709703 | 522 | len -= retval; |
1da177e4 LT |
523 | } |
524 | return copied; | |
525 | } | |
526 | ||
527 | int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len) | |
528 | { | |
529 | int copied = 0; | |
530 | ||
531 | while (len > 0) { | |
532 | char buf[128]; | |
533 | int this_len, retval; | |
534 | ||
535 | this_len = (len > sizeof(buf)) ? sizeof(buf) : len; | |
536 | if (copy_from_user(buf, src, this_len)) | |
537 | return -EFAULT; | |
538 | retval = access_process_vm(tsk, dst, buf, this_len, 1); | |
539 | if (!retval) { | |
540 | if (copied) | |
541 | break; | |
542 | return -EIO; | |
543 | } | |
544 | copied += retval; | |
545 | src += retval; | |
546 | dst += retval; | |
3a709703 | 547 | len -= retval; |
1da177e4 LT |
548 | } |
549 | return copied; | |
550 | } | |
551 | ||
4abf9869 | 552 | static int ptrace_setoptions(struct task_struct *child, unsigned long data) |
1da177e4 | 553 | { |
86b6c1f3 DV |
554 | unsigned flags; |
555 | ||
8c5cf9e5 DV |
556 | if (data & ~(unsigned long)PTRACE_O_MASK) |
557 | return -EINVAL; | |
558 | ||
13c4a901 TA |
559 | if (unlikely(data & PTRACE_O_SUSPEND_SECCOMP)) { |
560 | if (!config_enabled(CONFIG_CHECKPOINT_RESTORE) || | |
561 | !config_enabled(CONFIG_SECCOMP)) | |
562 | return -EINVAL; | |
563 | ||
564 | if (!capable(CAP_SYS_ADMIN)) | |
565 | return -EPERM; | |
566 | ||
567 | if (seccomp_mode(¤t->seccomp) != SECCOMP_MODE_DISABLED || | |
568 | current->ptrace & PT_SUSPEND_SECCOMP) | |
569 | return -EPERM; | |
570 | } | |
571 | ||
86b6c1f3 DV |
572 | /* Avoid intermediate state when all opts are cleared */ |
573 | flags = child->ptrace; | |
574 | flags &= ~(PTRACE_O_MASK << PT_OPT_FLAG_SHIFT); | |
575 | flags |= (data << PT_OPT_FLAG_SHIFT); | |
576 | child->ptrace = flags; | |
1da177e4 | 577 | |
8c5cf9e5 | 578 | return 0; |
1da177e4 LT |
579 | } |
580 | ||
e16b2781 | 581 | static int ptrace_getsiginfo(struct task_struct *child, siginfo_t *info) |
1da177e4 | 582 | { |
e4961254 | 583 | unsigned long flags; |
1da177e4 LT |
584 | int error = -ESRCH; |
585 | ||
e4961254 | 586 | if (lock_task_sighand(child, &flags)) { |
1da177e4 | 587 | error = -EINVAL; |
1da177e4 | 588 | if (likely(child->last_siginfo != NULL)) { |
e16b2781 | 589 | *info = *child->last_siginfo; |
1da177e4 LT |
590 | error = 0; |
591 | } | |
e4961254 | 592 | unlock_task_sighand(child, &flags); |
1da177e4 | 593 | } |
1da177e4 LT |
594 | return error; |
595 | } | |
596 | ||
e16b2781 | 597 | static int ptrace_setsiginfo(struct task_struct *child, const siginfo_t *info) |
1da177e4 | 598 | { |
e4961254 | 599 | unsigned long flags; |
1da177e4 LT |
600 | int error = -ESRCH; |
601 | ||
e4961254 | 602 | if (lock_task_sighand(child, &flags)) { |
1da177e4 | 603 | error = -EINVAL; |
1da177e4 | 604 | if (likely(child->last_siginfo != NULL)) { |
e16b2781 | 605 | *child->last_siginfo = *info; |
1da177e4 LT |
606 | error = 0; |
607 | } | |
e4961254 | 608 | unlock_task_sighand(child, &flags); |
1da177e4 | 609 | } |
1da177e4 LT |
610 | return error; |
611 | } | |
612 | ||
84c751bd AV |
613 | static int ptrace_peek_siginfo(struct task_struct *child, |
614 | unsigned long addr, | |
615 | unsigned long data) | |
616 | { | |
617 | struct ptrace_peeksiginfo_args arg; | |
618 | struct sigpending *pending; | |
619 | struct sigqueue *q; | |
620 | int ret, i; | |
621 | ||
622 | ret = copy_from_user(&arg, (void __user *) addr, | |
623 | sizeof(struct ptrace_peeksiginfo_args)); | |
624 | if (ret) | |
625 | return -EFAULT; | |
626 | ||
627 | if (arg.flags & ~PTRACE_PEEKSIGINFO_SHARED) | |
628 | return -EINVAL; /* unknown flags */ | |
629 | ||
630 | if (arg.nr < 0) | |
631 | return -EINVAL; | |
632 | ||
633 | if (arg.flags & PTRACE_PEEKSIGINFO_SHARED) | |
634 | pending = &child->signal->shared_pending; | |
635 | else | |
636 | pending = &child->pending; | |
637 | ||
638 | for (i = 0; i < arg.nr; ) { | |
639 | siginfo_t info; | |
640 | s32 off = arg.off + i; | |
641 | ||
642 | spin_lock_irq(&child->sighand->siglock); | |
643 | list_for_each_entry(q, &pending->list, list) { | |
644 | if (!off--) { | |
645 | copy_siginfo(&info, &q->info); | |
646 | break; | |
647 | } | |
648 | } | |
649 | spin_unlock_irq(&child->sighand->siglock); | |
650 | ||
651 | if (off >= 0) /* beyond the end of the list */ | |
652 | break; | |
653 | ||
654 | #ifdef CONFIG_COMPAT | |
655 | if (unlikely(is_compat_task())) { | |
656 | compat_siginfo_t __user *uinfo = compat_ptr(data); | |
657 | ||
706b23bd MD |
658 | if (copy_siginfo_to_user32(uinfo, &info) || |
659 | __put_user(info.si_code, &uinfo->si_code)) { | |
660 | ret = -EFAULT; | |
661 | break; | |
662 | } | |
663 | ||
84c751bd AV |
664 | } else |
665 | #endif | |
666 | { | |
667 | siginfo_t __user *uinfo = (siginfo_t __user *) data; | |
668 | ||
706b23bd MD |
669 | if (copy_siginfo_to_user(uinfo, &info) || |
670 | __put_user(info.si_code, &uinfo->si_code)) { | |
671 | ret = -EFAULT; | |
672 | break; | |
673 | } | |
84c751bd AV |
674 | } |
675 | ||
676 | data += sizeof(siginfo_t); | |
677 | i++; | |
678 | ||
679 | if (signal_pending(current)) | |
680 | break; | |
681 | ||
682 | cond_resched(); | |
683 | } | |
684 | ||
685 | if (i > 0) | |
686 | return i; | |
687 | ||
688 | return ret; | |
689 | } | |
36df29d7 RM |
690 | |
691 | #ifdef PTRACE_SINGLESTEP | |
692 | #define is_singlestep(request) ((request) == PTRACE_SINGLESTEP) | |
693 | #else | |
694 | #define is_singlestep(request) 0 | |
695 | #endif | |
696 | ||
5b88abbf RM |
697 | #ifdef PTRACE_SINGLEBLOCK |
698 | #define is_singleblock(request) ((request) == PTRACE_SINGLEBLOCK) | |
699 | #else | |
700 | #define is_singleblock(request) 0 | |
701 | #endif | |
702 | ||
36df29d7 RM |
703 | #ifdef PTRACE_SYSEMU |
704 | #define is_sysemu_singlestep(request) ((request) == PTRACE_SYSEMU_SINGLESTEP) | |
705 | #else | |
706 | #define is_sysemu_singlestep(request) 0 | |
707 | #endif | |
708 | ||
4abf9869 NK |
709 | static int ptrace_resume(struct task_struct *child, long request, |
710 | unsigned long data) | |
36df29d7 | 711 | { |
b72c1869 ON |
712 | bool need_siglock; |
713 | ||
36df29d7 RM |
714 | if (!valid_signal(data)) |
715 | return -EIO; | |
716 | ||
717 | if (request == PTRACE_SYSCALL) | |
718 | set_tsk_thread_flag(child, TIF_SYSCALL_TRACE); | |
719 | else | |
720 | clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); | |
721 | ||
722 | #ifdef TIF_SYSCALL_EMU | |
723 | if (request == PTRACE_SYSEMU || request == PTRACE_SYSEMU_SINGLESTEP) | |
724 | set_tsk_thread_flag(child, TIF_SYSCALL_EMU); | |
725 | else | |
726 | clear_tsk_thread_flag(child, TIF_SYSCALL_EMU); | |
727 | #endif | |
728 | ||
5b88abbf RM |
729 | if (is_singleblock(request)) { |
730 | if (unlikely(!arch_has_block_step())) | |
731 | return -EIO; | |
732 | user_enable_block_step(child); | |
733 | } else if (is_singlestep(request) || is_sysemu_singlestep(request)) { | |
36df29d7 RM |
734 | if (unlikely(!arch_has_single_step())) |
735 | return -EIO; | |
736 | user_enable_single_step(child); | |
3a709703 | 737 | } else { |
36df29d7 | 738 | user_disable_single_step(child); |
3a709703 | 739 | } |
36df29d7 | 740 | |
b72c1869 ON |
741 | /* |
742 | * Change ->exit_code and ->state under siglock to avoid the race | |
743 | * with wait_task_stopped() in between; a non-zero ->exit_code will | |
744 | * wrongly look like another report from tracee. | |
745 | * | |
746 | * Note that we need siglock even if ->exit_code == data and/or this | |
747 | * status was not reported yet, the new status must not be cleared by | |
748 | * wait_task_stopped() after resume. | |
749 | * | |
750 | * If data == 0 we do not care if wait_task_stopped() reports the old | |
751 | * status and clears the code too; this can't race with the tracee, it | |
752 | * takes siglock after resume. | |
753 | */ | |
754 | need_siglock = data && !thread_group_empty(current); | |
755 | if (need_siglock) | |
756 | spin_lock_irq(&child->sighand->siglock); | |
36df29d7 | 757 | child->exit_code = data; |
0666fb51 | 758 | wake_up_state(child, __TASK_TRACED); |
b72c1869 ON |
759 | if (need_siglock) |
760 | spin_unlock_irq(&child->sighand->siglock); | |
36df29d7 RM |
761 | |
762 | return 0; | |
763 | } | |
764 | ||
2225a122 SS |
765 | #ifdef CONFIG_HAVE_ARCH_TRACEHOOK |
766 | ||
767 | static const struct user_regset * | |
768 | find_regset(const struct user_regset_view *view, unsigned int type) | |
769 | { | |
770 | const struct user_regset *regset; | |
771 | int n; | |
772 | ||
773 | for (n = 0; n < view->n; ++n) { | |
774 | regset = view->regsets + n; | |
775 | if (regset->core_note_type == type) | |
776 | return regset; | |
777 | } | |
778 | ||
779 | return NULL; | |
780 | } | |
781 | ||
782 | static int ptrace_regset(struct task_struct *task, int req, unsigned int type, | |
783 | struct iovec *kiov) | |
784 | { | |
785 | const struct user_regset_view *view = task_user_regset_view(task); | |
786 | const struct user_regset *regset = find_regset(view, type); | |
787 | int regset_no; | |
788 | ||
789 | if (!regset || (kiov->iov_len % regset->size) != 0) | |
c6a0dd7e | 790 | return -EINVAL; |
2225a122 SS |
791 | |
792 | regset_no = regset - view->regsets; | |
793 | kiov->iov_len = min(kiov->iov_len, | |
794 | (__kernel_size_t) (regset->n * regset->size)); | |
795 | ||
796 | if (req == PTRACE_GETREGSET) | |
797 | return copy_regset_to_user(task, view, regset_no, 0, | |
798 | kiov->iov_len, kiov->iov_base); | |
799 | else | |
800 | return copy_regset_from_user(task, view, regset_no, 0, | |
801 | kiov->iov_len, kiov->iov_base); | |
802 | } | |
803 | ||
e8440c14 JS |
804 | /* |
805 | * This is declared in linux/regset.h and defined in machine-dependent | |
806 | * code. We put the export here, near the primary machine-neutral use, | |
807 | * to ensure no machine forgets it. | |
808 | */ | |
809 | EXPORT_SYMBOL_GPL(task_user_regset_view); | |
2225a122 SS |
810 | #endif |
811 | ||
1da177e4 | 812 | int ptrace_request(struct task_struct *child, long request, |
4abf9869 | 813 | unsigned long addr, unsigned long data) |
1da177e4 | 814 | { |
fca26f26 | 815 | bool seized = child->ptrace & PT_SEIZED; |
1da177e4 | 816 | int ret = -EIO; |
544b2c91 | 817 | siginfo_t siginfo, *si; |
9fed81dc NK |
818 | void __user *datavp = (void __user *) data; |
819 | unsigned long __user *datalp = datavp; | |
fca26f26 | 820 | unsigned long flags; |
1da177e4 LT |
821 | |
822 | switch (request) { | |
16c3e389 RM |
823 | case PTRACE_PEEKTEXT: |
824 | case PTRACE_PEEKDATA: | |
825 | return generic_ptrace_peekdata(child, addr, data); | |
826 | case PTRACE_POKETEXT: | |
827 | case PTRACE_POKEDATA: | |
828 | return generic_ptrace_pokedata(child, addr, data); | |
829 | ||
1da177e4 LT |
830 | #ifdef PTRACE_OLDSETOPTIONS |
831 | case PTRACE_OLDSETOPTIONS: | |
832 | #endif | |
833 | case PTRACE_SETOPTIONS: | |
834 | ret = ptrace_setoptions(child, data); | |
835 | break; | |
836 | case PTRACE_GETEVENTMSG: | |
9fed81dc | 837 | ret = put_user(child->ptrace_message, datalp); |
1da177e4 | 838 | break; |
e16b2781 | 839 | |
84c751bd AV |
840 | case PTRACE_PEEKSIGINFO: |
841 | ret = ptrace_peek_siginfo(child, addr, data); | |
842 | break; | |
843 | ||
1da177e4 | 844 | case PTRACE_GETSIGINFO: |
e16b2781 RM |
845 | ret = ptrace_getsiginfo(child, &siginfo); |
846 | if (!ret) | |
9fed81dc | 847 | ret = copy_siginfo_to_user(datavp, &siginfo); |
1da177e4 | 848 | break; |
e16b2781 | 849 | |
1da177e4 | 850 | case PTRACE_SETSIGINFO: |
9fed81dc | 851 | if (copy_from_user(&siginfo, datavp, sizeof siginfo)) |
e16b2781 RM |
852 | ret = -EFAULT; |
853 | else | |
854 | ret = ptrace_setsiginfo(child, &siginfo); | |
1da177e4 | 855 | break; |
e16b2781 | 856 | |
29000cae AV |
857 | case PTRACE_GETSIGMASK: |
858 | if (addr != sizeof(sigset_t)) { | |
859 | ret = -EINVAL; | |
860 | break; | |
861 | } | |
862 | ||
863 | if (copy_to_user(datavp, &child->blocked, sizeof(sigset_t))) | |
864 | ret = -EFAULT; | |
865 | else | |
866 | ret = 0; | |
867 | ||
868 | break; | |
869 | ||
870 | case PTRACE_SETSIGMASK: { | |
871 | sigset_t new_set; | |
872 | ||
873 | if (addr != sizeof(sigset_t)) { | |
874 | ret = -EINVAL; | |
875 | break; | |
876 | } | |
877 | ||
878 | if (copy_from_user(&new_set, datavp, sizeof(sigset_t))) { | |
879 | ret = -EFAULT; | |
880 | break; | |
881 | } | |
882 | ||
883 | sigdelsetmask(&new_set, sigmask(SIGKILL)|sigmask(SIGSTOP)); | |
884 | ||
885 | /* | |
886 | * Every thread does recalc_sigpending() after resume, so | |
887 | * retarget_shared_pending() and recalc_sigpending() are not | |
888 | * called here. | |
889 | */ | |
890 | spin_lock_irq(&child->sighand->siglock); | |
891 | child->blocked = new_set; | |
892 | spin_unlock_irq(&child->sighand->siglock); | |
893 | ||
894 | ret = 0; | |
895 | break; | |
896 | } | |
897 | ||
fca26f26 TH |
898 | case PTRACE_INTERRUPT: |
899 | /* | |
900 | * Stop tracee without any side-effect on signal or job | |
901 | * control. At least one trap is guaranteed to happen | |
902 | * after this request. If @child is already trapped, the | |
903 | * current trap is not disturbed and another trap will | |
904 | * happen after the current trap is ended with PTRACE_CONT. | |
905 | * | |
906 | * The actual trap might not be PTRACE_EVENT_STOP trap but | |
907 | * the pending condition is cleared regardless. | |
908 | */ | |
909 | if (unlikely(!seized || !lock_task_sighand(child, &flags))) | |
910 | break; | |
911 | ||
544b2c91 TH |
912 | /* |
913 | * INTERRUPT doesn't disturb existing trap sans one | |
914 | * exception. If ptracer issued LISTEN for the current | |
915 | * STOP, this INTERRUPT should clear LISTEN and re-trap | |
916 | * tracee into STOP. | |
917 | */ | |
fca26f26 | 918 | if (likely(task_set_jobctl_pending(child, JOBCTL_TRAP_STOP))) |
910ffdb1 | 919 | ptrace_signal_wake_up(child, child->jobctl & JOBCTL_LISTENING); |
544b2c91 TH |
920 | |
921 | unlock_task_sighand(child, &flags); | |
922 | ret = 0; | |
923 | break; | |
924 | ||
925 | case PTRACE_LISTEN: | |
926 | /* | |
927 | * Listen for events. Tracee must be in STOP. It's not | |
928 | * resumed per-se but is not considered to be in TRACED by | |
929 | * wait(2) or ptrace(2). If an async event (e.g. group | |
930 | * stop state change) happens, tracee will enter STOP trap | |
931 | * again. Alternatively, ptracer can issue INTERRUPT to | |
932 | * finish listening and re-trap tracee into STOP. | |
933 | */ | |
934 | if (unlikely(!seized || !lock_task_sighand(child, &flags))) | |
935 | break; | |
936 | ||
937 | si = child->last_siginfo; | |
f9d81f61 ON |
938 | if (likely(si && (si->si_code >> 8) == PTRACE_EVENT_STOP)) { |
939 | child->jobctl |= JOBCTL_LISTENING; | |
940 | /* | |
941 | * If NOTIFY is set, it means event happened between | |
942 | * start of this trap and now. Trigger re-trap. | |
943 | */ | |
944 | if (child->jobctl & JOBCTL_TRAP_NOTIFY) | |
910ffdb1 | 945 | ptrace_signal_wake_up(child, true); |
f9d81f61 ON |
946 | ret = 0; |
947 | } | |
fca26f26 | 948 | unlock_task_sighand(child, &flags); |
fca26f26 TH |
949 | break; |
950 | ||
1bcf5482 AD |
951 | case PTRACE_DETACH: /* detach a process that was attached. */ |
952 | ret = ptrace_detach(child, data); | |
953 | break; | |
36df29d7 | 954 | |
9c1a1259 MF |
955 | #ifdef CONFIG_BINFMT_ELF_FDPIC |
956 | case PTRACE_GETFDPIC: { | |
e0129ef9 | 957 | struct mm_struct *mm = get_task_mm(child); |
9c1a1259 MF |
958 | unsigned long tmp = 0; |
959 | ||
e0129ef9 ON |
960 | ret = -ESRCH; |
961 | if (!mm) | |
962 | break; | |
963 | ||
9c1a1259 MF |
964 | switch (addr) { |
965 | case PTRACE_GETFDPIC_EXEC: | |
e0129ef9 | 966 | tmp = mm->context.exec_fdpic_loadmap; |
9c1a1259 MF |
967 | break; |
968 | case PTRACE_GETFDPIC_INTERP: | |
e0129ef9 | 969 | tmp = mm->context.interp_fdpic_loadmap; |
9c1a1259 MF |
970 | break; |
971 | default: | |
972 | break; | |
973 | } | |
e0129ef9 | 974 | mmput(mm); |
9c1a1259 | 975 | |
9fed81dc | 976 | ret = put_user(tmp, datalp); |
9c1a1259 MF |
977 | break; |
978 | } | |
979 | #endif | |
980 | ||
36df29d7 RM |
981 | #ifdef PTRACE_SINGLESTEP |
982 | case PTRACE_SINGLESTEP: | |
983 | #endif | |
5b88abbf RM |
984 | #ifdef PTRACE_SINGLEBLOCK |
985 | case PTRACE_SINGLEBLOCK: | |
986 | #endif | |
36df29d7 RM |
987 | #ifdef PTRACE_SYSEMU |
988 | case PTRACE_SYSEMU: | |
989 | case PTRACE_SYSEMU_SINGLESTEP: | |
990 | #endif | |
991 | case PTRACE_SYSCALL: | |
992 | case PTRACE_CONT: | |
993 | return ptrace_resume(child, request, data); | |
994 | ||
995 | case PTRACE_KILL: | |
996 | if (child->exit_state) /* already dead */ | |
997 | return 0; | |
998 | return ptrace_resume(child, request, SIGKILL); | |
999 | ||
2225a122 SS |
1000 | #ifdef CONFIG_HAVE_ARCH_TRACEHOOK |
1001 | case PTRACE_GETREGSET: | |
29000cae | 1002 | case PTRACE_SETREGSET: { |
2225a122 | 1003 | struct iovec kiov; |
9fed81dc | 1004 | struct iovec __user *uiov = datavp; |
2225a122 SS |
1005 | |
1006 | if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov))) | |
1007 | return -EFAULT; | |
1008 | ||
1009 | if (__get_user(kiov.iov_base, &uiov->iov_base) || | |
1010 | __get_user(kiov.iov_len, &uiov->iov_len)) | |
1011 | return -EFAULT; | |
1012 | ||
1013 | ret = ptrace_regset(child, request, addr, &kiov); | |
1014 | if (!ret) | |
1015 | ret = __put_user(kiov.iov_len, &uiov->iov_len); | |
1016 | break; | |
1017 | } | |
1018 | #endif | |
f8e529ed TA |
1019 | |
1020 | case PTRACE_SECCOMP_GET_FILTER: | |
1021 | ret = seccomp_get_filter(child, addr, datavp); | |
1022 | break; | |
1023 | ||
1da177e4 LT |
1024 | default: |
1025 | break; | |
1026 | } | |
1027 | ||
1028 | return ret; | |
1029 | } | |
481bed45 | 1030 | |
8053bdd5 | 1031 | static struct task_struct *ptrace_get_task_struct(pid_t pid) |
6b9c7ed8 CH |
1032 | { |
1033 | struct task_struct *child; | |
481bed45 | 1034 | |
8053bdd5 | 1035 | rcu_read_lock(); |
228ebcbe | 1036 | child = find_task_by_vpid(pid); |
481bed45 CH |
1037 | if (child) |
1038 | get_task_struct(child); | |
8053bdd5 | 1039 | rcu_read_unlock(); |
f400e198 | 1040 | |
481bed45 | 1041 | if (!child) |
6b9c7ed8 CH |
1042 | return ERR_PTR(-ESRCH); |
1043 | return child; | |
481bed45 CH |
1044 | } |
1045 | ||
0ac15559 CH |
1046 | #ifndef arch_ptrace_attach |
1047 | #define arch_ptrace_attach(child) do { } while (0) | |
1048 | #endif | |
1049 | ||
4abf9869 NK |
1050 | SYSCALL_DEFINE4(ptrace, long, request, long, pid, unsigned long, addr, |
1051 | unsigned long, data) | |
481bed45 CH |
1052 | { |
1053 | struct task_struct *child; | |
1054 | long ret; | |
1055 | ||
6b9c7ed8 CH |
1056 | if (request == PTRACE_TRACEME) { |
1057 | ret = ptrace_traceme(); | |
6ea6dd93 HS |
1058 | if (!ret) |
1059 | arch_ptrace_attach(current); | |
481bed45 | 1060 | goto out; |
6b9c7ed8 CH |
1061 | } |
1062 | ||
1063 | child = ptrace_get_task_struct(pid); | |
1064 | if (IS_ERR(child)) { | |
1065 | ret = PTR_ERR(child); | |
1066 | goto out; | |
1067 | } | |
481bed45 | 1068 | |
3544d72a | 1069 | if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) { |
aa9147c9 | 1070 | ret = ptrace_attach(child, request, addr, data); |
0ac15559 CH |
1071 | /* |
1072 | * Some architectures need to do book-keeping after | |
1073 | * a ptrace attach. | |
1074 | */ | |
1075 | if (!ret) | |
1076 | arch_ptrace_attach(child); | |
005f18df | 1077 | goto out_put_task_struct; |
481bed45 CH |
1078 | } |
1079 | ||
fca26f26 TH |
1080 | ret = ptrace_check_attach(child, request == PTRACE_KILL || |
1081 | request == PTRACE_INTERRUPT); | |
481bed45 CH |
1082 | if (ret < 0) |
1083 | goto out_put_task_struct; | |
1084 | ||
1085 | ret = arch_ptrace(child, request, addr, data); | |
9899d11f ON |
1086 | if (ret || request != PTRACE_DETACH) |
1087 | ptrace_unfreeze_traced(child); | |
481bed45 CH |
1088 | |
1089 | out_put_task_struct: | |
1090 | put_task_struct(child); | |
1091 | out: | |
481bed45 CH |
1092 | return ret; |
1093 | } | |
76647323 | 1094 | |
4abf9869 NK |
1095 | int generic_ptrace_peekdata(struct task_struct *tsk, unsigned long addr, |
1096 | unsigned long data) | |
76647323 AD |
1097 | { |
1098 | unsigned long tmp; | |
1099 | int copied; | |
1100 | ||
1101 | copied = access_process_vm(tsk, addr, &tmp, sizeof(tmp), 0); | |
1102 | if (copied != sizeof(tmp)) | |
1103 | return -EIO; | |
1104 | return put_user(tmp, (unsigned long __user *)data); | |
1105 | } | |
f284ce72 | 1106 | |
4abf9869 NK |
1107 | int generic_ptrace_pokedata(struct task_struct *tsk, unsigned long addr, |
1108 | unsigned long data) | |
f284ce72 AD |
1109 | { |
1110 | int copied; | |
1111 | ||
1112 | copied = access_process_vm(tsk, addr, &data, sizeof(data), 1); | |
1113 | return (copied == sizeof(data)) ? 0 : -EIO; | |
1114 | } | |
032d82d9 | 1115 | |
96b8936a | 1116 | #if defined CONFIG_COMPAT |
032d82d9 RM |
1117 | |
1118 | int compat_ptrace_request(struct task_struct *child, compat_long_t request, | |
1119 | compat_ulong_t addr, compat_ulong_t data) | |
1120 | { | |
1121 | compat_ulong_t __user *datap = compat_ptr(data); | |
1122 | compat_ulong_t word; | |
e16b2781 | 1123 | siginfo_t siginfo; |
032d82d9 RM |
1124 | int ret; |
1125 | ||
1126 | switch (request) { | |
1127 | case PTRACE_PEEKTEXT: | |
1128 | case PTRACE_PEEKDATA: | |
1129 | ret = access_process_vm(child, addr, &word, sizeof(word), 0); | |
1130 | if (ret != sizeof(word)) | |
1131 | ret = -EIO; | |
1132 | else | |
1133 | ret = put_user(word, datap); | |
1134 | break; | |
1135 | ||
1136 | case PTRACE_POKETEXT: | |
1137 | case PTRACE_POKEDATA: | |
1138 | ret = access_process_vm(child, addr, &data, sizeof(data), 1); | |
1139 | ret = (ret != sizeof(data) ? -EIO : 0); | |
1140 | break; | |
1141 | ||
1142 | case PTRACE_GETEVENTMSG: | |
1143 | ret = put_user((compat_ulong_t) child->ptrace_message, datap); | |
1144 | break; | |
1145 | ||
e16b2781 RM |
1146 | case PTRACE_GETSIGINFO: |
1147 | ret = ptrace_getsiginfo(child, &siginfo); | |
1148 | if (!ret) | |
1149 | ret = copy_siginfo_to_user32( | |
1150 | (struct compat_siginfo __user *) datap, | |
1151 | &siginfo); | |
1152 | break; | |
1153 | ||
1154 | case PTRACE_SETSIGINFO: | |
1155 | memset(&siginfo, 0, sizeof siginfo); | |
1156 | if (copy_siginfo_from_user32( | |
1157 | &siginfo, (struct compat_siginfo __user *) datap)) | |
1158 | ret = -EFAULT; | |
1159 | else | |
1160 | ret = ptrace_setsiginfo(child, &siginfo); | |
1161 | break; | |
2225a122 SS |
1162 | #ifdef CONFIG_HAVE_ARCH_TRACEHOOK |
1163 | case PTRACE_GETREGSET: | |
1164 | case PTRACE_SETREGSET: | |
1165 | { | |
1166 | struct iovec kiov; | |
1167 | struct compat_iovec __user *uiov = | |
1168 | (struct compat_iovec __user *) datap; | |
1169 | compat_uptr_t ptr; | |
1170 | compat_size_t len; | |
1171 | ||
1172 | if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov))) | |
1173 | return -EFAULT; | |
1174 | ||
1175 | if (__get_user(ptr, &uiov->iov_base) || | |
1176 | __get_user(len, &uiov->iov_len)) | |
1177 | return -EFAULT; | |
1178 | ||
1179 | kiov.iov_base = compat_ptr(ptr); | |
1180 | kiov.iov_len = len; | |
1181 | ||
1182 | ret = ptrace_regset(child, request, addr, &kiov); | |
1183 | if (!ret) | |
1184 | ret = __put_user(kiov.iov_len, &uiov->iov_len); | |
1185 | break; | |
1186 | } | |
1187 | #endif | |
e16b2781 | 1188 | |
032d82d9 RM |
1189 | default: |
1190 | ret = ptrace_request(child, request, addr, data); | |
1191 | } | |
1192 | ||
1193 | return ret; | |
1194 | } | |
c269f196 | 1195 | |
62a6fa97 HC |
1196 | COMPAT_SYSCALL_DEFINE4(ptrace, compat_long_t, request, compat_long_t, pid, |
1197 | compat_long_t, addr, compat_long_t, data) | |
c269f196 RM |
1198 | { |
1199 | struct task_struct *child; | |
1200 | long ret; | |
1201 | ||
c269f196 RM |
1202 | if (request == PTRACE_TRACEME) { |
1203 | ret = ptrace_traceme(); | |
1204 | goto out; | |
1205 | } | |
1206 | ||
1207 | child = ptrace_get_task_struct(pid); | |
1208 | if (IS_ERR(child)) { | |
1209 | ret = PTR_ERR(child); | |
1210 | goto out; | |
1211 | } | |
1212 | ||
3544d72a | 1213 | if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) { |
aa9147c9 | 1214 | ret = ptrace_attach(child, request, addr, data); |
c269f196 RM |
1215 | /* |
1216 | * Some architectures need to do book-keeping after | |
1217 | * a ptrace attach. | |
1218 | */ | |
1219 | if (!ret) | |
1220 | arch_ptrace_attach(child); | |
1221 | goto out_put_task_struct; | |
1222 | } | |
1223 | ||
fca26f26 TH |
1224 | ret = ptrace_check_attach(child, request == PTRACE_KILL || |
1225 | request == PTRACE_INTERRUPT); | |
9899d11f | 1226 | if (!ret) { |
c269f196 | 1227 | ret = compat_arch_ptrace(child, request, addr, data); |
9899d11f ON |
1228 | if (ret || request != PTRACE_DETACH) |
1229 | ptrace_unfreeze_traced(child); | |
1230 | } | |
c269f196 RM |
1231 | |
1232 | out_put_task_struct: | |
1233 | put_task_struct(child); | |
1234 | out: | |
c269f196 RM |
1235 | return ret; |
1236 | } | |
96b8936a | 1237 | #endif /* CONFIG_COMPAT */ |