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> |
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 | |
62c124ff TH |
31 | static int ptrace_trapping_sleep_fn(void *flags) |
32 | { | |
33 | schedule(); | |
34 | return 0; | |
35 | } | |
36 | ||
1da177e4 LT |
37 | /* |
38 | * ptrace a task: make the debugger its new parent and | |
39 | * move it to the ptrace list. | |
40 | * | |
41 | * Must be called with the tasklist lock write-held. | |
42 | */ | |
36c8b586 | 43 | void __ptrace_link(struct task_struct *child, struct task_struct *new_parent) |
1da177e4 | 44 | { |
f470021a RM |
45 | BUG_ON(!list_empty(&child->ptrace_entry)); |
46 | list_add(&child->ptrace_entry, &new_parent->ptraced); | |
1da177e4 | 47 | child->parent = new_parent; |
1da177e4 | 48 | } |
3a709703 | 49 | |
e3bd058f TH |
50 | /** |
51 | * __ptrace_unlink - unlink ptracee and restore its execution state | |
52 | * @child: ptracee to be unlinked | |
1da177e4 | 53 | * |
0e9f0a4a TH |
54 | * Remove @child from the ptrace list, move it back to the original parent, |
55 | * and restore the execution state so that it conforms to the group stop | |
56 | * state. | |
57 | * | |
58 | * Unlinking can happen via two paths - explicit PTRACE_DETACH or ptracer | |
59 | * exiting. For PTRACE_DETACH, unless the ptracee has been killed between | |
60 | * ptrace_check_attach() and here, it's guaranteed to be in TASK_TRACED. | |
61 | * If the ptracer is exiting, the ptracee can be in any state. | |
62 | * | |
63 | * After detach, the ptracee should be in a state which conforms to the | |
64 | * group stop. If the group is stopped or in the process of stopping, the | |
65 | * ptracee should be put into TASK_STOPPED; otherwise, it should be woken | |
66 | * up from TASK_TRACED. | |
67 | * | |
68 | * If the ptracee is in TASK_TRACED and needs to be moved to TASK_STOPPED, | |
69 | * it goes through TRACED -> RUNNING -> STOPPED transition which is similar | |
70 | * to but in the opposite direction of what happens while attaching to a | |
71 | * stopped task. However, in this direction, the intermediate RUNNING | |
72 | * state is not hidden even from the current ptracer and if it immediately | |
73 | * re-attaches and performs a WNOHANG wait(2), it may fail. | |
e3bd058f TH |
74 | * |
75 | * CONTEXT: | |
76 | * write_lock_irq(tasklist_lock) | |
1da177e4 | 77 | */ |
36c8b586 | 78 | void __ptrace_unlink(struct task_struct *child) |
1da177e4 | 79 | { |
5ecfbae0 ON |
80 | BUG_ON(!child->ptrace); |
81 | ||
1da177e4 | 82 | child->ptrace = 0; |
f470021a RM |
83 | child->parent = child->real_parent; |
84 | list_del_init(&child->ptrace_entry); | |
1da177e4 | 85 | |
1da177e4 | 86 | spin_lock(&child->sighand->siglock); |
0e9f0a4a | 87 | |
73ddff2b TH |
88 | /* |
89 | * Clear all pending traps and TRAPPING. TRAPPING should be | |
90 | * cleared regardless of JOBCTL_STOP_PENDING. Do it explicitly. | |
91 | */ | |
92 | task_clear_jobctl_pending(child, JOBCTL_TRAP_MASK); | |
93 | task_clear_jobctl_trapping(child); | |
94 | ||
0e9f0a4a | 95 | /* |
a8f072c1 | 96 | * Reinstate JOBCTL_STOP_PENDING if group stop is in effect and |
0e9f0a4a TH |
97 | * @child isn't dead. |
98 | */ | |
99 | if (!(child->flags & PF_EXITING) && | |
100 | (child->signal->flags & SIGNAL_STOP_STOPPED || | |
8a88951b | 101 | child->signal->group_stop_count)) { |
a8f072c1 | 102 | child->jobctl |= JOBCTL_STOP_PENDING; |
0e9f0a4a | 103 | |
8a88951b ON |
104 | /* |
105 | * This is only possible if this thread was cloned by the | |
106 | * traced task running in the stopped group, set the signal | |
107 | * for the future reports. | |
108 | * FIXME: we should change ptrace_init_task() to handle this | |
109 | * case. | |
110 | */ | |
111 | if (!(child->jobctl & JOBCTL_STOP_SIGMASK)) | |
112 | child->jobctl |= SIGSTOP; | |
113 | } | |
114 | ||
0e9f0a4a TH |
115 | /* |
116 | * If transition to TASK_STOPPED is pending or in TASK_TRACED, kick | |
117 | * @child in the butt. Note that @resume should be used iff @child | |
118 | * is in TASK_TRACED; otherwise, we might unduly disrupt | |
119 | * TASK_KILLABLE sleeps. | |
120 | */ | |
a8f072c1 | 121 | if (child->jobctl & JOBCTL_STOP_PENDING || task_is_traced(child)) |
910ffdb1 | 122 | ptrace_signal_wake_up(child, true); |
0e9f0a4a | 123 | |
1da177e4 | 124 | spin_unlock(&child->sighand->siglock); |
1da177e4 LT |
125 | } |
126 | ||
9899d11f ON |
127 | /* Ensure that nothing can wake it up, even SIGKILL */ |
128 | static bool ptrace_freeze_traced(struct task_struct *task) | |
129 | { | |
130 | bool ret = false; | |
131 | ||
132 | /* Lockless, nobody but us can set this flag */ | |
133 | if (task->jobctl & JOBCTL_LISTENING) | |
134 | return ret; | |
135 | ||
136 | spin_lock_irq(&task->sighand->siglock); | |
137 | if (task_is_traced(task) && !__fatal_signal_pending(task)) { | |
138 | task->state = __TASK_TRACED; | |
139 | ret = true; | |
140 | } | |
141 | spin_unlock_irq(&task->sighand->siglock); | |
142 | ||
143 | return ret; | |
144 | } | |
145 | ||
146 | static void ptrace_unfreeze_traced(struct task_struct *task) | |
147 | { | |
148 | if (task->state != __TASK_TRACED) | |
149 | return; | |
150 | ||
151 | WARN_ON(!task->ptrace || task->parent != current); | |
152 | ||
153 | spin_lock_irq(&task->sighand->siglock); | |
154 | if (__fatal_signal_pending(task)) | |
155 | wake_up_state(task, __TASK_TRACED); | |
156 | else | |
157 | task->state = TASK_TRACED; | |
158 | spin_unlock_irq(&task->sighand->siglock); | |
159 | } | |
160 | ||
755e276b TH |
161 | /** |
162 | * ptrace_check_attach - check whether ptracee is ready for ptrace operation | |
163 | * @child: ptracee to check for | |
164 | * @ignore_state: don't check whether @child is currently %TASK_TRACED | |
165 | * | |
166 | * Check whether @child is being ptraced by %current and ready for further | |
167 | * ptrace operations. If @ignore_state is %false, @child also should be in | |
168 | * %TASK_TRACED state and on return the child is guaranteed to be traced | |
169 | * and not executing. If @ignore_state is %true, @child can be in any | |
170 | * state. | |
171 | * | |
172 | * CONTEXT: | |
173 | * Grabs and releases tasklist_lock and @child->sighand->siglock. | |
174 | * | |
175 | * RETURNS: | |
176 | * 0 on success, -ESRCH if %child is not ready. | |
1da177e4 | 177 | */ |
edea0d03 | 178 | static int ptrace_check_attach(struct task_struct *child, bool ignore_state) |
1da177e4 LT |
179 | { |
180 | int ret = -ESRCH; | |
181 | ||
182 | /* | |
183 | * We take the read lock around doing both checks to close a | |
184 | * possible race where someone else was tracing our child and | |
185 | * detached between these two checks. After this locked check, | |
186 | * we are sure that this is our traced child and that can only | |
187 | * be changed by us so it's not changing right after this. | |
188 | */ | |
189 | read_lock(&tasklist_lock); | |
9899d11f ON |
190 | if (child->ptrace && child->parent == current) { |
191 | WARN_ON(child->state == __TASK_TRACED); | |
c0c0b649 ON |
192 | /* |
193 | * child->sighand can't be NULL, release_task() | |
194 | * does ptrace_unlink() before __exit_signal(). | |
195 | */ | |
9899d11f | 196 | if (ignore_state || ptrace_freeze_traced(child)) |
321fb561 | 197 | ret = 0; |
1da177e4 LT |
198 | } |
199 | read_unlock(&tasklist_lock); | |
200 | ||
9899d11f ON |
201 | if (!ret && !ignore_state) { |
202 | if (!wait_task_inactive(child, __TASK_TRACED)) { | |
203 | /* | |
204 | * This can only happen if may_ptrace_stop() fails and | |
205 | * ptrace_stop() changes ->state back to TASK_RUNNING, | |
206 | * so we should not worry about leaking __TASK_TRACED. | |
207 | */ | |
208 | WARN_ON(child->state == __TASK_TRACED); | |
209 | ret = -ESRCH; | |
210 | } | |
211 | } | |
1da177e4 | 212 | |
1da177e4 LT |
213 | return ret; |
214 | } | |
215 | ||
69f594a3 EP |
216 | static int ptrace_has_cap(struct user_namespace *ns, unsigned int mode) |
217 | { | |
218 | if (mode & PTRACE_MODE_NOAUDIT) | |
219 | return has_ns_capability_noaudit(current, ns, CAP_SYS_PTRACE); | |
220 | else | |
221 | return has_ns_capability(current, ns, CAP_SYS_PTRACE); | |
222 | } | |
223 | ||
9f99798f TH |
224 | /* Returns 0 on success, -errno on denial. */ |
225 | static int __ptrace_may_access(struct task_struct *task, unsigned int mode) | |
ab8d11be | 226 | { |
c69e8d9c | 227 | const struct cred *cred = current_cred(), *tcred; |
414f6fbc JH |
228 | int dumpable = 0; |
229 | kuid_t caller_uid; | |
230 | kgid_t caller_gid; | |
231 | ||
232 | if (!(mode & PTRACE_MODE_FSCREDS) == !(mode & PTRACE_MODE_REALCREDS)) { | |
233 | WARN(1, "denying ptrace access check without PTRACE_MODE_*CREDS\n"); | |
234 | return -EPERM; | |
235 | } | |
b6dff3ec | 236 | |
df26c40e EB |
237 | /* May we inspect the given task? |
238 | * This check is used both for attaching with ptrace | |
239 | * and for allowing access to sensitive information in /proc. | |
240 | * | |
241 | * ptrace_attach denies several cases that /proc allows | |
242 | * because setting up the necessary parent/child relationship | |
243 | * or halting the specified task is impossible. | |
244 | */ | |
414f6fbc | 245 | |
df26c40e | 246 | /* Don't let security modules deny introspection */ |
a20cc70d | 247 | if (same_thread_group(task, current)) |
df26c40e | 248 | return 0; |
c69e8d9c | 249 | rcu_read_lock(); |
414f6fbc JH |
250 | if (mode & PTRACE_MODE_FSCREDS) { |
251 | caller_uid = cred->fsuid; | |
252 | caller_gid = cred->fsgid; | |
253 | } else { | |
254 | /* | |
255 | * Using the euid would make more sense here, but something | |
256 | * in userland might rely on the old behavior, and this | |
257 | * shouldn't be a security problem since | |
258 | * PTRACE_MODE_REALCREDS implies that the caller explicitly | |
259 | * used a syscall that requests access to another process | |
260 | * (and not a filesystem syscall to procfs). | |
261 | */ | |
262 | caller_uid = cred->uid; | |
263 | caller_gid = cred->gid; | |
264 | } | |
c69e8d9c | 265 | tcred = __task_cred(task); |
414f6fbc JH |
266 | if (uid_eq(caller_uid, tcred->euid) && |
267 | uid_eq(caller_uid, tcred->suid) && | |
268 | uid_eq(caller_uid, tcred->uid) && | |
269 | gid_eq(caller_gid, tcred->egid) && | |
270 | gid_eq(caller_gid, tcred->sgid) && | |
271 | gid_eq(caller_gid, tcred->gid)) | |
8409cca7 | 272 | goto ok; |
c4a4d603 | 273 | if (ptrace_has_cap(tcred->user_ns, mode)) |
8409cca7 SH |
274 | goto ok; |
275 | rcu_read_unlock(); | |
276 | return -EPERM; | |
277 | ok: | |
c69e8d9c | 278 | rcu_read_unlock(); |
ab8d11be | 279 | smp_rmb(); |
df26c40e | 280 | if (task->mm) |
6c5d5238 | 281 | dumpable = get_dumpable(task->mm); |
4c44aaaf | 282 | rcu_read_lock(); |
d389d610 KC |
283 | if (dumpable != SUID_DUMP_USER && |
284 | !ptrace_has_cap(__task_cred(task)->user_ns, mode)) { | |
4c44aaaf | 285 | rcu_read_unlock(); |
ab8d11be | 286 | return -EPERM; |
4c44aaaf EB |
287 | } |
288 | rcu_read_unlock(); | |
ab8d11be | 289 | |
9e48858f | 290 | return security_ptrace_access_check(task, mode); |
ab8d11be MS |
291 | } |
292 | ||
006ebb40 | 293 | bool ptrace_may_access(struct task_struct *task, unsigned int mode) |
ab8d11be MS |
294 | { |
295 | int err; | |
296 | task_lock(task); | |
006ebb40 | 297 | err = __ptrace_may_access(task, mode); |
ab8d11be | 298 | task_unlock(task); |
3a709703 | 299 | return !err; |
ab8d11be MS |
300 | } |
301 | ||
3544d72a | 302 | static int ptrace_attach(struct task_struct *task, long request, |
aa9147c9 | 303 | unsigned long addr, |
3544d72a | 304 | unsigned long flags) |
1da177e4 | 305 | { |
3544d72a | 306 | bool seize = (request == PTRACE_SEIZE); |
1da177e4 | 307 | int retval; |
f5b40e36 | 308 | |
3544d72a | 309 | retval = -EIO; |
aa9147c9 DV |
310 | if (seize) { |
311 | if (addr != 0) | |
312 | goto out; | |
aa9147c9 DV |
313 | if (flags & ~(unsigned long)PTRACE_O_MASK) |
314 | goto out; | |
315 | flags = PT_PTRACED | PT_SEIZED | (flags << PT_OPT_FLAG_SHIFT); | |
316 | } else { | |
317 | flags = PT_PTRACED; | |
318 | } | |
3544d72a | 319 | |
a5cb013d AV |
320 | audit_ptrace(task); |
321 | ||
1da177e4 | 322 | retval = -EPERM; |
b79b7ba9 ON |
323 | if (unlikely(task->flags & PF_KTHREAD)) |
324 | goto out; | |
bac0abd6 | 325 | if (same_thread_group(task, current)) |
f5b40e36 LT |
326 | goto out; |
327 | ||
f2f0b00a ON |
328 | /* |
329 | * Protect exec's credential calculations against our interference; | |
86b6c1f3 | 330 | * SUID, SGID and LSM creds get determined differently |
5e751e99 | 331 | * under ptrace. |
d84f4f99 | 332 | */ |
793285fc | 333 | retval = -ERESTARTNOINTR; |
9b1bf12d | 334 | if (mutex_lock_interruptible(&task->signal->cred_guard_mutex)) |
d84f4f99 | 335 | goto out; |
f5b40e36 | 336 | |
4b105cbb | 337 | task_lock(task); |
414f6fbc | 338 | retval = __ptrace_may_access(task, PTRACE_MODE_ATTACH_REALCREDS); |
4b105cbb | 339 | task_unlock(task); |
1da177e4 | 340 | if (retval) |
4b105cbb | 341 | goto unlock_creds; |
1da177e4 | 342 | |
4b105cbb | 343 | write_lock_irq(&tasklist_lock); |
b79b7ba9 ON |
344 | retval = -EPERM; |
345 | if (unlikely(task->exit_state)) | |
4b105cbb | 346 | goto unlock_tasklist; |
f2f0b00a | 347 | if (task->ptrace) |
4b105cbb | 348 | goto unlock_tasklist; |
b79b7ba9 | 349 | |
3544d72a | 350 | if (seize) |
aa9147c9 | 351 | flags |= PT_SEIZED; |
4c44aaaf EB |
352 | rcu_read_lock(); |
353 | if (ns_capable(__task_cred(task)->user_ns, CAP_SYS_PTRACE)) | |
aa9147c9 | 354 | flags |= PT_PTRACE_CAP; |
4c44aaaf | 355 | rcu_read_unlock(); |
aa9147c9 | 356 | task->ptrace = flags; |
1da177e4 | 357 | |
1da177e4 | 358 | __ptrace_link(task, current); |
3544d72a TH |
359 | |
360 | /* SEIZE doesn't trap tracee on attach */ | |
361 | if (!seize) | |
362 | send_sig_info(SIGSTOP, SEND_SIG_FORCED, task); | |
b79b7ba9 | 363 | |
d79fdd6d TH |
364 | spin_lock(&task->sighand->siglock); |
365 | ||
366 | /* | |
73ddff2b | 367 | * If the task is already STOPPED, set JOBCTL_TRAP_STOP and |
d79fdd6d TH |
368 | * TRAPPING, and kick it so that it transits to TRACED. TRAPPING |
369 | * will be cleared if the child completes the transition or any | |
370 | * event which clears the group stop states happens. We'll wait | |
371 | * for the transition to complete before returning from this | |
372 | * function. | |
373 | * | |
374 | * This hides STOPPED -> RUNNING -> TRACED transition from the | |
375 | * attaching thread but a different thread in the same group can | |
376 | * still observe the transient RUNNING state. IOW, if another | |
377 | * thread's WNOHANG wait(2) on the stopped tracee races against | |
378 | * ATTACH, the wait(2) may fail due to the transient RUNNING. | |
379 | * | |
380 | * The following task_is_stopped() test is safe as both transitions | |
381 | * in and out of STOPPED are protected by siglock. | |
382 | */ | |
7dd3db54 | 383 | if (task_is_stopped(task) && |
73ddff2b | 384 | task_set_jobctl_pending(task, JOBCTL_TRAP_STOP | JOBCTL_TRAPPING)) |
910ffdb1 | 385 | signal_wake_up_state(task, __TASK_STOPPED); |
d79fdd6d TH |
386 | |
387 | spin_unlock(&task->sighand->siglock); | |
388 | ||
b79b7ba9 | 389 | retval = 0; |
4b105cbb ON |
390 | unlock_tasklist: |
391 | write_unlock_irq(&tasklist_lock); | |
392 | unlock_creds: | |
9b1bf12d | 393 | mutex_unlock(&task->signal->cred_guard_mutex); |
f5b40e36 | 394 | out: |
f701e5b7 | 395 | if (!retval) { |
62c124ff TH |
396 | wait_on_bit(&task->jobctl, JOBCTL_TRAPPING_BIT, |
397 | ptrace_trapping_sleep_fn, TASK_UNINTERRUPTIBLE); | |
f701e5b7 VZ |
398 | proc_ptrace_connector(task, PTRACE_ATTACH); |
399 | } | |
400 | ||
1da177e4 LT |
401 | return retval; |
402 | } | |
403 | ||
f2f0b00a ON |
404 | /** |
405 | * ptrace_traceme -- helper for PTRACE_TRACEME | |
406 | * | |
407 | * Performs checks and sets PT_PTRACED. | |
408 | * Should be used by all ptrace implementations for PTRACE_TRACEME. | |
409 | */ | |
e3e89cc5 | 410 | static int ptrace_traceme(void) |
f2f0b00a ON |
411 | { |
412 | int ret = -EPERM; | |
413 | ||
4b105cbb ON |
414 | write_lock_irq(&tasklist_lock); |
415 | /* Are we already being traced? */ | |
f2f0b00a | 416 | if (!current->ptrace) { |
f2f0b00a | 417 | ret = security_ptrace_traceme(current->parent); |
f2f0b00a ON |
418 | /* |
419 | * Check PF_EXITING to ensure ->real_parent has not passed | |
420 | * exit_ptrace(). Otherwise we don't report the error but | |
421 | * pretend ->real_parent untraces us right after return. | |
422 | */ | |
423 | if (!ret && !(current->real_parent->flags & PF_EXITING)) { | |
424 | current->ptrace = PT_PTRACED; | |
425 | __ptrace_link(current, current->real_parent); | |
426 | } | |
f2f0b00a | 427 | } |
4b105cbb ON |
428 | write_unlock_irq(&tasklist_lock); |
429 | ||
f2f0b00a ON |
430 | return ret; |
431 | } | |
432 | ||
39c626ae ON |
433 | /* |
434 | * Called with irqs disabled, returns true if childs should reap themselves. | |
435 | */ | |
436 | static int ignoring_children(struct sighand_struct *sigh) | |
437 | { | |
438 | int ret; | |
439 | spin_lock(&sigh->siglock); | |
440 | ret = (sigh->action[SIGCHLD-1].sa.sa_handler == SIG_IGN) || | |
441 | (sigh->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT); | |
442 | spin_unlock(&sigh->siglock); | |
443 | return ret; | |
444 | } | |
445 | ||
446 | /* | |
447 | * Called with tasklist_lock held for writing. | |
448 | * Unlink a traced task, and clean it up if it was a traced zombie. | |
449 | * Return true if it needs to be reaped with release_task(). | |
450 | * (We can't call release_task() here because we already hold tasklist_lock.) | |
451 | * | |
452 | * If it's a zombie, our attachedness prevented normal parent notification | |
453 | * or self-reaping. Do notification now if it would have happened earlier. | |
454 | * If it should reap itself, return true. | |
455 | * | |
a7f0765e ON |
456 | * If it's our own child, there is no notification to do. But if our normal |
457 | * children self-reap, then this child was prevented by ptrace and we must | |
458 | * reap it now, in that case we must also wake up sub-threads sleeping in | |
459 | * do_wait(). | |
39c626ae ON |
460 | */ |
461 | static bool __ptrace_detach(struct task_struct *tracer, struct task_struct *p) | |
462 | { | |
9843a1e9 ON |
463 | bool dead; |
464 | ||
39c626ae ON |
465 | __ptrace_unlink(p); |
466 | ||
9843a1e9 ON |
467 | if (p->exit_state != EXIT_ZOMBIE) |
468 | return false; | |
469 | ||
470 | dead = !thread_group_leader(p); | |
471 | ||
472 | if (!dead && thread_group_empty(p)) { | |
473 | if (!same_thread_group(p->real_parent, tracer)) | |
474 | dead = do_notify_parent(p, p->exit_signal); | |
475 | else if (ignoring_children(tracer->sighand)) { | |
476 | __wake_up_parent(p, tracer); | |
9843a1e9 | 477 | dead = true; |
39c626ae ON |
478 | } |
479 | } | |
9843a1e9 ON |
480 | /* Mark it as in the process of being reaped. */ |
481 | if (dead) | |
482 | p->exit_state = EXIT_DEAD; | |
483 | return dead; | |
39c626ae ON |
484 | } |
485 | ||
e3e89cc5 | 486 | static int ptrace_detach(struct task_struct *child, unsigned int data) |
1da177e4 | 487 | { |
39c626ae | 488 | bool dead = false; |
4576145c | 489 | |
7ed20e1a | 490 | if (!valid_signal(data)) |
5ecfbae0 | 491 | return -EIO; |
1da177e4 LT |
492 | |
493 | /* Architecture-specific hardware disable .. */ | |
494 | ptrace_disable(child); | |
7d941432 | 495 | clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); |
1da177e4 | 496 | |
95c3eb76 | 497 | write_lock_irq(&tasklist_lock); |
39c626ae ON |
498 | /* |
499 | * This child can be already killed. Make sure de_thread() or | |
500 | * our sub-thread doing do_wait() didn't do release_task() yet. | |
501 | */ | |
95c3eb76 ON |
502 | if (child->ptrace) { |
503 | child->exit_code = data; | |
4576145c | 504 | dead = __ptrace_detach(current, child); |
95c3eb76 | 505 | } |
1da177e4 LT |
506 | write_unlock_irq(&tasklist_lock); |
507 | ||
f701e5b7 | 508 | proc_ptrace_connector(child, PTRACE_DETACH); |
4576145c ON |
509 | if (unlikely(dead)) |
510 | release_task(child); | |
511 | ||
1da177e4 LT |
512 | return 0; |
513 | } | |
514 | ||
39c626ae | 515 | /* |
c7e49c14 ON |
516 | * Detach all tasks we were using ptrace on. Called with tasklist held |
517 | * for writing, and returns with it held too. But note it can release | |
518 | * and reacquire the lock. | |
39c626ae ON |
519 | */ |
520 | void exit_ptrace(struct task_struct *tracer) | |
c4b5ed25 NK |
521 | __releases(&tasklist_lock) |
522 | __acquires(&tasklist_lock) | |
39c626ae ON |
523 | { |
524 | struct task_struct *p, *n; | |
525 | LIST_HEAD(ptrace_dead); | |
526 | ||
c7e49c14 ON |
527 | if (likely(list_empty(&tracer->ptraced))) |
528 | return; | |
529 | ||
39c626ae | 530 | list_for_each_entry_safe(p, n, &tracer->ptraced, ptrace_entry) { |
992fb6e1 ON |
531 | if (unlikely(p->ptrace & PT_EXITKILL)) |
532 | send_sig_info(SIGKILL, SEND_SIG_FORCED, p); | |
533 | ||
39c626ae ON |
534 | if (__ptrace_detach(tracer, p)) |
535 | list_add(&p->ptrace_entry, &ptrace_dead); | |
536 | } | |
39c626ae | 537 | |
c7e49c14 | 538 | write_unlock_irq(&tasklist_lock); |
39c626ae ON |
539 | BUG_ON(!list_empty(&tracer->ptraced)); |
540 | ||
541 | list_for_each_entry_safe(p, n, &ptrace_dead, ptrace_entry) { | |
542 | list_del_init(&p->ptrace_entry); | |
543 | release_task(p); | |
544 | } | |
c7e49c14 ON |
545 | |
546 | write_lock_irq(&tasklist_lock); | |
39c626ae ON |
547 | } |
548 | ||
1da177e4 LT |
549 | int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len) |
550 | { | |
551 | int copied = 0; | |
552 | ||
553 | while (len > 0) { | |
554 | char buf[128]; | |
555 | int this_len, retval; | |
556 | ||
557 | this_len = (len > sizeof(buf)) ? sizeof(buf) : len; | |
558 | retval = access_process_vm(tsk, src, buf, this_len, 0); | |
559 | if (!retval) { | |
560 | if (copied) | |
561 | break; | |
562 | return -EIO; | |
563 | } | |
564 | if (copy_to_user(dst, buf, retval)) | |
565 | return -EFAULT; | |
566 | copied += retval; | |
567 | src += retval; | |
568 | dst += retval; | |
3a709703 | 569 | len -= retval; |
1da177e4 LT |
570 | } |
571 | return copied; | |
572 | } | |
573 | ||
574 | int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len) | |
575 | { | |
576 | int copied = 0; | |
577 | ||
578 | while (len > 0) { | |
579 | char buf[128]; | |
580 | int this_len, retval; | |
581 | ||
582 | this_len = (len > sizeof(buf)) ? sizeof(buf) : len; | |
583 | if (copy_from_user(buf, src, this_len)) | |
584 | return -EFAULT; | |
585 | retval = access_process_vm(tsk, dst, buf, this_len, 1); | |
586 | if (!retval) { | |
587 | if (copied) | |
588 | break; | |
589 | return -EIO; | |
590 | } | |
591 | copied += retval; | |
592 | src += retval; | |
593 | dst += retval; | |
3a709703 | 594 | len -= retval; |
1da177e4 LT |
595 | } |
596 | return copied; | |
597 | } | |
598 | ||
4abf9869 | 599 | static int ptrace_setoptions(struct task_struct *child, unsigned long data) |
1da177e4 | 600 | { |
86b6c1f3 DV |
601 | unsigned flags; |
602 | ||
8c5cf9e5 DV |
603 | if (data & ~(unsigned long)PTRACE_O_MASK) |
604 | return -EINVAL; | |
605 | ||
86b6c1f3 DV |
606 | /* Avoid intermediate state when all opts are cleared */ |
607 | flags = child->ptrace; | |
608 | flags &= ~(PTRACE_O_MASK << PT_OPT_FLAG_SHIFT); | |
609 | flags |= (data << PT_OPT_FLAG_SHIFT); | |
610 | child->ptrace = flags; | |
1da177e4 | 611 | |
8c5cf9e5 | 612 | return 0; |
1da177e4 LT |
613 | } |
614 | ||
e16b2781 | 615 | static int ptrace_getsiginfo(struct task_struct *child, siginfo_t *info) |
1da177e4 | 616 | { |
e4961254 | 617 | unsigned long flags; |
1da177e4 LT |
618 | int error = -ESRCH; |
619 | ||
e4961254 | 620 | if (lock_task_sighand(child, &flags)) { |
1da177e4 | 621 | error = -EINVAL; |
1da177e4 | 622 | if (likely(child->last_siginfo != NULL)) { |
e16b2781 | 623 | *info = *child->last_siginfo; |
1da177e4 LT |
624 | error = 0; |
625 | } | |
e4961254 | 626 | unlock_task_sighand(child, &flags); |
1da177e4 | 627 | } |
1da177e4 LT |
628 | return error; |
629 | } | |
630 | ||
e16b2781 | 631 | static int ptrace_setsiginfo(struct task_struct *child, const siginfo_t *info) |
1da177e4 | 632 | { |
e4961254 | 633 | unsigned long flags; |
1da177e4 LT |
634 | int error = -ESRCH; |
635 | ||
e4961254 | 636 | if (lock_task_sighand(child, &flags)) { |
1da177e4 | 637 | error = -EINVAL; |
1da177e4 | 638 | if (likely(child->last_siginfo != NULL)) { |
e16b2781 | 639 | *child->last_siginfo = *info; |
1da177e4 LT |
640 | error = 0; |
641 | } | |
e4961254 | 642 | unlock_task_sighand(child, &flags); |
1da177e4 | 643 | } |
1da177e4 LT |
644 | return error; |
645 | } | |
646 | ||
84c751bd AV |
647 | static int ptrace_peek_siginfo(struct task_struct *child, |
648 | unsigned long addr, | |
649 | unsigned long data) | |
650 | { | |
651 | struct ptrace_peeksiginfo_args arg; | |
652 | struct sigpending *pending; | |
653 | struct sigqueue *q; | |
654 | int ret, i; | |
655 | ||
656 | ret = copy_from_user(&arg, (void __user *) addr, | |
657 | sizeof(struct ptrace_peeksiginfo_args)); | |
658 | if (ret) | |
659 | return -EFAULT; | |
660 | ||
661 | if (arg.flags & ~PTRACE_PEEKSIGINFO_SHARED) | |
662 | return -EINVAL; /* unknown flags */ | |
663 | ||
664 | if (arg.nr < 0) | |
665 | return -EINVAL; | |
666 | ||
667 | if (arg.flags & PTRACE_PEEKSIGINFO_SHARED) | |
668 | pending = &child->signal->shared_pending; | |
669 | else | |
670 | pending = &child->pending; | |
671 | ||
672 | for (i = 0; i < arg.nr; ) { | |
673 | siginfo_t info; | |
674 | s32 off = arg.off + i; | |
675 | ||
676 | spin_lock_irq(&child->sighand->siglock); | |
677 | list_for_each_entry(q, &pending->list, list) { | |
678 | if (!off--) { | |
679 | copy_siginfo(&info, &q->info); | |
680 | break; | |
681 | } | |
682 | } | |
683 | spin_unlock_irq(&child->sighand->siglock); | |
684 | ||
685 | if (off >= 0) /* beyond the end of the list */ | |
686 | break; | |
687 | ||
688 | #ifdef CONFIG_COMPAT | |
689 | if (unlikely(is_compat_task())) { | |
690 | compat_siginfo_t __user *uinfo = compat_ptr(data); | |
691 | ||
706b23bd MD |
692 | if (copy_siginfo_to_user32(uinfo, &info) || |
693 | __put_user(info.si_code, &uinfo->si_code)) { | |
694 | ret = -EFAULT; | |
695 | break; | |
696 | } | |
697 | ||
84c751bd AV |
698 | } else |
699 | #endif | |
700 | { | |
701 | siginfo_t __user *uinfo = (siginfo_t __user *) data; | |
702 | ||
706b23bd MD |
703 | if (copy_siginfo_to_user(uinfo, &info) || |
704 | __put_user(info.si_code, &uinfo->si_code)) { | |
705 | ret = -EFAULT; | |
706 | break; | |
707 | } | |
84c751bd AV |
708 | } |
709 | ||
710 | data += sizeof(siginfo_t); | |
711 | i++; | |
712 | ||
713 | if (signal_pending(current)) | |
714 | break; | |
715 | ||
716 | cond_resched(); | |
717 | } | |
718 | ||
719 | if (i > 0) | |
720 | return i; | |
721 | ||
722 | return ret; | |
723 | } | |
36df29d7 RM |
724 | |
725 | #ifdef PTRACE_SINGLESTEP | |
726 | #define is_singlestep(request) ((request) == PTRACE_SINGLESTEP) | |
727 | #else | |
728 | #define is_singlestep(request) 0 | |
729 | #endif | |
730 | ||
5b88abbf RM |
731 | #ifdef PTRACE_SINGLEBLOCK |
732 | #define is_singleblock(request) ((request) == PTRACE_SINGLEBLOCK) | |
733 | #else | |
734 | #define is_singleblock(request) 0 | |
735 | #endif | |
736 | ||
36df29d7 RM |
737 | #ifdef PTRACE_SYSEMU |
738 | #define is_sysemu_singlestep(request) ((request) == PTRACE_SYSEMU_SINGLESTEP) | |
739 | #else | |
740 | #define is_sysemu_singlestep(request) 0 | |
741 | #endif | |
742 | ||
4abf9869 NK |
743 | static int ptrace_resume(struct task_struct *child, long request, |
744 | unsigned long data) | |
36df29d7 | 745 | { |
ddb56eac ON |
746 | bool need_siglock; |
747 | ||
36df29d7 RM |
748 | if (!valid_signal(data)) |
749 | return -EIO; | |
750 | ||
751 | if (request == PTRACE_SYSCALL) | |
752 | set_tsk_thread_flag(child, TIF_SYSCALL_TRACE); | |
753 | else | |
754 | clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); | |
755 | ||
756 | #ifdef TIF_SYSCALL_EMU | |
757 | if (request == PTRACE_SYSEMU || request == PTRACE_SYSEMU_SINGLESTEP) | |
758 | set_tsk_thread_flag(child, TIF_SYSCALL_EMU); | |
759 | else | |
760 | clear_tsk_thread_flag(child, TIF_SYSCALL_EMU); | |
761 | #endif | |
762 | ||
5b88abbf RM |
763 | if (is_singleblock(request)) { |
764 | if (unlikely(!arch_has_block_step())) | |
765 | return -EIO; | |
766 | user_enable_block_step(child); | |
767 | } else if (is_singlestep(request) || is_sysemu_singlestep(request)) { | |
36df29d7 RM |
768 | if (unlikely(!arch_has_single_step())) |
769 | return -EIO; | |
770 | user_enable_single_step(child); | |
3a709703 | 771 | } else { |
36df29d7 | 772 | user_disable_single_step(child); |
3a709703 | 773 | } |
36df29d7 | 774 | |
ddb56eac ON |
775 | /* |
776 | * Change ->exit_code and ->state under siglock to avoid the race | |
777 | * with wait_task_stopped() in between; a non-zero ->exit_code will | |
778 | * wrongly look like another report from tracee. | |
779 | * | |
780 | * Note that we need siglock even if ->exit_code == data and/or this | |
781 | * status was not reported yet, the new status must not be cleared by | |
782 | * wait_task_stopped() after resume. | |
783 | * | |
784 | * If data == 0 we do not care if wait_task_stopped() reports the old | |
785 | * status and clears the code too; this can't race with the tracee, it | |
786 | * takes siglock after resume. | |
787 | */ | |
788 | need_siglock = data && !thread_group_empty(current); | |
789 | if (need_siglock) | |
790 | spin_lock_irq(&child->sighand->siglock); | |
36df29d7 | 791 | child->exit_code = data; |
0666fb51 | 792 | wake_up_state(child, __TASK_TRACED); |
ddb56eac ON |
793 | if (need_siglock) |
794 | spin_unlock_irq(&child->sighand->siglock); | |
36df29d7 RM |
795 | |
796 | return 0; | |
797 | } | |
798 | ||
2225a122 SS |
799 | #ifdef CONFIG_HAVE_ARCH_TRACEHOOK |
800 | ||
801 | static const struct user_regset * | |
802 | find_regset(const struct user_regset_view *view, unsigned int type) | |
803 | { | |
804 | const struct user_regset *regset; | |
805 | int n; | |
806 | ||
807 | for (n = 0; n < view->n; ++n) { | |
808 | regset = view->regsets + n; | |
809 | if (regset->core_note_type == type) | |
810 | return regset; | |
811 | } | |
812 | ||
813 | return NULL; | |
814 | } | |
815 | ||
816 | static int ptrace_regset(struct task_struct *task, int req, unsigned int type, | |
817 | struct iovec *kiov) | |
818 | { | |
819 | const struct user_regset_view *view = task_user_regset_view(task); | |
820 | const struct user_regset *regset = find_regset(view, type); | |
821 | int regset_no; | |
822 | ||
823 | if (!regset || (kiov->iov_len % regset->size) != 0) | |
c6a0dd7e | 824 | return -EINVAL; |
2225a122 SS |
825 | |
826 | regset_no = regset - view->regsets; | |
827 | kiov->iov_len = min(kiov->iov_len, | |
828 | (__kernel_size_t) (regset->n * regset->size)); | |
829 | ||
830 | if (req == PTRACE_GETREGSET) | |
831 | return copy_regset_to_user(task, view, regset_no, 0, | |
832 | kiov->iov_len, kiov->iov_base); | |
833 | else | |
834 | return copy_regset_from_user(task, view, regset_no, 0, | |
835 | kiov->iov_len, kiov->iov_base); | |
836 | } | |
837 | ||
e8440c14 JS |
838 | /* |
839 | * This is declared in linux/regset.h and defined in machine-dependent | |
840 | * code. We put the export here, near the primary machine-neutral use, | |
841 | * to ensure no machine forgets it. | |
842 | */ | |
843 | EXPORT_SYMBOL_GPL(task_user_regset_view); | |
2225a122 SS |
844 | #endif |
845 | ||
1da177e4 | 846 | int ptrace_request(struct task_struct *child, long request, |
4abf9869 | 847 | unsigned long addr, unsigned long data) |
1da177e4 | 848 | { |
fca26f26 | 849 | bool seized = child->ptrace & PT_SEIZED; |
1da177e4 | 850 | int ret = -EIO; |
544b2c91 | 851 | siginfo_t siginfo, *si; |
9fed81dc NK |
852 | void __user *datavp = (void __user *) data; |
853 | unsigned long __user *datalp = datavp; | |
fca26f26 | 854 | unsigned long flags; |
1da177e4 LT |
855 | |
856 | switch (request) { | |
16c3e389 RM |
857 | case PTRACE_PEEKTEXT: |
858 | case PTRACE_PEEKDATA: | |
859 | return generic_ptrace_peekdata(child, addr, data); | |
860 | case PTRACE_POKETEXT: | |
861 | case PTRACE_POKEDATA: | |
862 | return generic_ptrace_pokedata(child, addr, data); | |
863 | ||
1da177e4 LT |
864 | #ifdef PTRACE_OLDSETOPTIONS |
865 | case PTRACE_OLDSETOPTIONS: | |
866 | #endif | |
867 | case PTRACE_SETOPTIONS: | |
868 | ret = ptrace_setoptions(child, data); | |
869 | break; | |
870 | case PTRACE_GETEVENTMSG: | |
9fed81dc | 871 | ret = put_user(child->ptrace_message, datalp); |
1da177e4 | 872 | break; |
e16b2781 | 873 | |
84c751bd AV |
874 | case PTRACE_PEEKSIGINFO: |
875 | ret = ptrace_peek_siginfo(child, addr, data); | |
876 | break; | |
877 | ||
1da177e4 | 878 | case PTRACE_GETSIGINFO: |
e16b2781 RM |
879 | ret = ptrace_getsiginfo(child, &siginfo); |
880 | if (!ret) | |
9fed81dc | 881 | ret = copy_siginfo_to_user(datavp, &siginfo); |
1da177e4 | 882 | break; |
e16b2781 | 883 | |
1da177e4 | 884 | case PTRACE_SETSIGINFO: |
9fed81dc | 885 | if (copy_from_user(&siginfo, datavp, sizeof siginfo)) |
e16b2781 RM |
886 | ret = -EFAULT; |
887 | else | |
888 | ret = ptrace_setsiginfo(child, &siginfo); | |
1da177e4 | 889 | break; |
e16b2781 | 890 | |
fca26f26 TH |
891 | case PTRACE_INTERRUPT: |
892 | /* | |
893 | * Stop tracee without any side-effect on signal or job | |
894 | * control. At least one trap is guaranteed to happen | |
895 | * after this request. If @child is already trapped, the | |
896 | * current trap is not disturbed and another trap will | |
897 | * happen after the current trap is ended with PTRACE_CONT. | |
898 | * | |
899 | * The actual trap might not be PTRACE_EVENT_STOP trap but | |
900 | * the pending condition is cleared regardless. | |
901 | */ | |
902 | if (unlikely(!seized || !lock_task_sighand(child, &flags))) | |
903 | break; | |
904 | ||
544b2c91 TH |
905 | /* |
906 | * INTERRUPT doesn't disturb existing trap sans one | |
907 | * exception. If ptracer issued LISTEN for the current | |
908 | * STOP, this INTERRUPT should clear LISTEN and re-trap | |
909 | * tracee into STOP. | |
910 | */ | |
fca26f26 | 911 | if (likely(task_set_jobctl_pending(child, JOBCTL_TRAP_STOP))) |
910ffdb1 | 912 | ptrace_signal_wake_up(child, child->jobctl & JOBCTL_LISTENING); |
544b2c91 TH |
913 | |
914 | unlock_task_sighand(child, &flags); | |
915 | ret = 0; | |
916 | break; | |
917 | ||
918 | case PTRACE_LISTEN: | |
919 | /* | |
920 | * Listen for events. Tracee must be in STOP. It's not | |
921 | * resumed per-se but is not considered to be in TRACED by | |
922 | * wait(2) or ptrace(2). If an async event (e.g. group | |
923 | * stop state change) happens, tracee will enter STOP trap | |
924 | * again. Alternatively, ptracer can issue INTERRUPT to | |
925 | * finish listening and re-trap tracee into STOP. | |
926 | */ | |
927 | if (unlikely(!seized || !lock_task_sighand(child, &flags))) | |
928 | break; | |
929 | ||
930 | si = child->last_siginfo; | |
f9d81f61 ON |
931 | if (likely(si && (si->si_code >> 8) == PTRACE_EVENT_STOP)) { |
932 | child->jobctl |= JOBCTL_LISTENING; | |
933 | /* | |
934 | * If NOTIFY is set, it means event happened between | |
935 | * start of this trap and now. Trigger re-trap. | |
936 | */ | |
937 | if (child->jobctl & JOBCTL_TRAP_NOTIFY) | |
910ffdb1 | 938 | ptrace_signal_wake_up(child, true); |
f9d81f61 ON |
939 | ret = 0; |
940 | } | |
fca26f26 | 941 | unlock_task_sighand(child, &flags); |
fca26f26 TH |
942 | break; |
943 | ||
1bcf5482 AD |
944 | case PTRACE_DETACH: /* detach a process that was attached. */ |
945 | ret = ptrace_detach(child, data); | |
946 | break; | |
36df29d7 | 947 | |
9c1a1259 MF |
948 | #ifdef CONFIG_BINFMT_ELF_FDPIC |
949 | case PTRACE_GETFDPIC: { | |
e0129ef9 | 950 | struct mm_struct *mm = get_task_mm(child); |
9c1a1259 MF |
951 | unsigned long tmp = 0; |
952 | ||
e0129ef9 ON |
953 | ret = -ESRCH; |
954 | if (!mm) | |
955 | break; | |
956 | ||
9c1a1259 MF |
957 | switch (addr) { |
958 | case PTRACE_GETFDPIC_EXEC: | |
e0129ef9 | 959 | tmp = mm->context.exec_fdpic_loadmap; |
9c1a1259 MF |
960 | break; |
961 | case PTRACE_GETFDPIC_INTERP: | |
e0129ef9 | 962 | tmp = mm->context.interp_fdpic_loadmap; |
9c1a1259 MF |
963 | break; |
964 | default: | |
965 | break; | |
966 | } | |
e0129ef9 | 967 | mmput(mm); |
9c1a1259 | 968 | |
9fed81dc | 969 | ret = put_user(tmp, datalp); |
9c1a1259 MF |
970 | break; |
971 | } | |
972 | #endif | |
973 | ||
36df29d7 RM |
974 | #ifdef PTRACE_SINGLESTEP |
975 | case PTRACE_SINGLESTEP: | |
976 | #endif | |
5b88abbf RM |
977 | #ifdef PTRACE_SINGLEBLOCK |
978 | case PTRACE_SINGLEBLOCK: | |
979 | #endif | |
36df29d7 RM |
980 | #ifdef PTRACE_SYSEMU |
981 | case PTRACE_SYSEMU: | |
982 | case PTRACE_SYSEMU_SINGLESTEP: | |
983 | #endif | |
984 | case PTRACE_SYSCALL: | |
985 | case PTRACE_CONT: | |
986 | return ptrace_resume(child, request, data); | |
987 | ||
988 | case PTRACE_KILL: | |
989 | if (child->exit_state) /* already dead */ | |
990 | return 0; | |
991 | return ptrace_resume(child, request, SIGKILL); | |
992 | ||
2225a122 SS |
993 | #ifdef CONFIG_HAVE_ARCH_TRACEHOOK |
994 | case PTRACE_GETREGSET: | |
995 | case PTRACE_SETREGSET: | |
996 | { | |
997 | struct iovec kiov; | |
9fed81dc | 998 | struct iovec __user *uiov = datavp; |
2225a122 SS |
999 | |
1000 | if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov))) | |
1001 | return -EFAULT; | |
1002 | ||
1003 | if (__get_user(kiov.iov_base, &uiov->iov_base) || | |
1004 | __get_user(kiov.iov_len, &uiov->iov_len)) | |
1005 | return -EFAULT; | |
1006 | ||
1007 | ret = ptrace_regset(child, request, addr, &kiov); | |
1008 | if (!ret) | |
1009 | ret = __put_user(kiov.iov_len, &uiov->iov_len); | |
1010 | break; | |
1011 | } | |
1012 | #endif | |
1da177e4 LT |
1013 | default: |
1014 | break; | |
1015 | } | |
1016 | ||
1017 | return ret; | |
1018 | } | |
481bed45 | 1019 | |
8053bdd5 | 1020 | static struct task_struct *ptrace_get_task_struct(pid_t pid) |
6b9c7ed8 CH |
1021 | { |
1022 | struct task_struct *child; | |
481bed45 | 1023 | |
8053bdd5 | 1024 | rcu_read_lock(); |
228ebcbe | 1025 | child = find_task_by_vpid(pid); |
481bed45 CH |
1026 | if (child) |
1027 | get_task_struct(child); | |
8053bdd5 | 1028 | rcu_read_unlock(); |
f400e198 | 1029 | |
481bed45 | 1030 | if (!child) |
6b9c7ed8 CH |
1031 | return ERR_PTR(-ESRCH); |
1032 | return child; | |
481bed45 CH |
1033 | } |
1034 | ||
0ac15559 CH |
1035 | #ifndef arch_ptrace_attach |
1036 | #define arch_ptrace_attach(child) do { } while (0) | |
1037 | #endif | |
1038 | ||
4abf9869 NK |
1039 | SYSCALL_DEFINE4(ptrace, long, request, long, pid, unsigned long, addr, |
1040 | unsigned long, data) | |
481bed45 CH |
1041 | { |
1042 | struct task_struct *child; | |
1043 | long ret; | |
1044 | ||
6b9c7ed8 CH |
1045 | if (request == PTRACE_TRACEME) { |
1046 | ret = ptrace_traceme(); | |
6ea6dd93 HS |
1047 | if (!ret) |
1048 | arch_ptrace_attach(current); | |
481bed45 | 1049 | goto out; |
6b9c7ed8 CH |
1050 | } |
1051 | ||
1052 | child = ptrace_get_task_struct(pid); | |
1053 | if (IS_ERR(child)) { | |
1054 | ret = PTR_ERR(child); | |
1055 | goto out; | |
1056 | } | |
481bed45 | 1057 | |
3544d72a | 1058 | if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) { |
aa9147c9 | 1059 | ret = ptrace_attach(child, request, addr, data); |
0ac15559 CH |
1060 | /* |
1061 | * Some architectures need to do book-keeping after | |
1062 | * a ptrace attach. | |
1063 | */ | |
1064 | if (!ret) | |
1065 | arch_ptrace_attach(child); | |
005f18df | 1066 | goto out_put_task_struct; |
481bed45 CH |
1067 | } |
1068 | ||
fca26f26 TH |
1069 | ret = ptrace_check_attach(child, request == PTRACE_KILL || |
1070 | request == PTRACE_INTERRUPT); | |
481bed45 CH |
1071 | if (ret < 0) |
1072 | goto out_put_task_struct; | |
1073 | ||
1074 | ret = arch_ptrace(child, request, addr, data); | |
9899d11f ON |
1075 | if (ret || request != PTRACE_DETACH) |
1076 | ptrace_unfreeze_traced(child); | |
481bed45 CH |
1077 | |
1078 | out_put_task_struct: | |
1079 | put_task_struct(child); | |
1080 | out: | |
481bed45 CH |
1081 | return ret; |
1082 | } | |
76647323 | 1083 | |
4abf9869 NK |
1084 | int generic_ptrace_peekdata(struct task_struct *tsk, unsigned long addr, |
1085 | unsigned long data) | |
76647323 AD |
1086 | { |
1087 | unsigned long tmp; | |
1088 | int copied; | |
1089 | ||
1090 | copied = access_process_vm(tsk, addr, &tmp, sizeof(tmp), 0); | |
1091 | if (copied != sizeof(tmp)) | |
1092 | return -EIO; | |
1093 | return put_user(tmp, (unsigned long __user *)data); | |
1094 | } | |
f284ce72 | 1095 | |
4abf9869 NK |
1096 | int generic_ptrace_pokedata(struct task_struct *tsk, unsigned long addr, |
1097 | unsigned long data) | |
f284ce72 AD |
1098 | { |
1099 | int copied; | |
1100 | ||
1101 | copied = access_process_vm(tsk, addr, &data, sizeof(data), 1); | |
1102 | return (copied == sizeof(data)) ? 0 : -EIO; | |
1103 | } | |
032d82d9 | 1104 | |
96b8936a | 1105 | #if defined CONFIG_COMPAT |
032d82d9 RM |
1106 | #include <linux/compat.h> |
1107 | ||
1108 | int compat_ptrace_request(struct task_struct *child, compat_long_t request, | |
1109 | compat_ulong_t addr, compat_ulong_t data) | |
1110 | { | |
1111 | compat_ulong_t __user *datap = compat_ptr(data); | |
1112 | compat_ulong_t word; | |
e16b2781 | 1113 | siginfo_t siginfo; |
032d82d9 RM |
1114 | int ret; |
1115 | ||
1116 | switch (request) { | |
1117 | case PTRACE_PEEKTEXT: | |
1118 | case PTRACE_PEEKDATA: | |
1119 | ret = access_process_vm(child, addr, &word, sizeof(word), 0); | |
1120 | if (ret != sizeof(word)) | |
1121 | ret = -EIO; | |
1122 | else | |
1123 | ret = put_user(word, datap); | |
1124 | break; | |
1125 | ||
1126 | case PTRACE_POKETEXT: | |
1127 | case PTRACE_POKEDATA: | |
1128 | ret = access_process_vm(child, addr, &data, sizeof(data), 1); | |
1129 | ret = (ret != sizeof(data) ? -EIO : 0); | |
1130 | break; | |
1131 | ||
1132 | case PTRACE_GETEVENTMSG: | |
1133 | ret = put_user((compat_ulong_t) child->ptrace_message, datap); | |
1134 | break; | |
1135 | ||
e16b2781 RM |
1136 | case PTRACE_GETSIGINFO: |
1137 | ret = ptrace_getsiginfo(child, &siginfo); | |
1138 | if (!ret) | |
1139 | ret = copy_siginfo_to_user32( | |
1140 | (struct compat_siginfo __user *) datap, | |
1141 | &siginfo); | |
1142 | break; | |
1143 | ||
1144 | case PTRACE_SETSIGINFO: | |
1145 | memset(&siginfo, 0, sizeof siginfo); | |
1146 | if (copy_siginfo_from_user32( | |
1147 | &siginfo, (struct compat_siginfo __user *) datap)) | |
1148 | ret = -EFAULT; | |
1149 | else | |
1150 | ret = ptrace_setsiginfo(child, &siginfo); | |
1151 | break; | |
2225a122 SS |
1152 | #ifdef CONFIG_HAVE_ARCH_TRACEHOOK |
1153 | case PTRACE_GETREGSET: | |
1154 | case PTRACE_SETREGSET: | |
1155 | { | |
1156 | struct iovec kiov; | |
1157 | struct compat_iovec __user *uiov = | |
1158 | (struct compat_iovec __user *) datap; | |
1159 | compat_uptr_t ptr; | |
1160 | compat_size_t len; | |
1161 | ||
1162 | if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov))) | |
1163 | return -EFAULT; | |
1164 | ||
1165 | if (__get_user(ptr, &uiov->iov_base) || | |
1166 | __get_user(len, &uiov->iov_len)) | |
1167 | return -EFAULT; | |
1168 | ||
1169 | kiov.iov_base = compat_ptr(ptr); | |
1170 | kiov.iov_len = len; | |
1171 | ||
1172 | ret = ptrace_regset(child, request, addr, &kiov); | |
1173 | if (!ret) | |
1174 | ret = __put_user(kiov.iov_len, &uiov->iov_len); | |
1175 | break; | |
1176 | } | |
1177 | #endif | |
e16b2781 | 1178 | |
032d82d9 RM |
1179 | default: |
1180 | ret = ptrace_request(child, request, addr, data); | |
1181 | } | |
1182 | ||
1183 | return ret; | |
1184 | } | |
c269f196 | 1185 | |
c269f196 RM |
1186 | asmlinkage long compat_sys_ptrace(compat_long_t request, compat_long_t pid, |
1187 | compat_long_t addr, compat_long_t data) | |
1188 | { | |
1189 | struct task_struct *child; | |
1190 | long ret; | |
1191 | ||
c269f196 RM |
1192 | if (request == PTRACE_TRACEME) { |
1193 | ret = ptrace_traceme(); | |
1194 | goto out; | |
1195 | } | |
1196 | ||
1197 | child = ptrace_get_task_struct(pid); | |
1198 | if (IS_ERR(child)) { | |
1199 | ret = PTR_ERR(child); | |
1200 | goto out; | |
1201 | } | |
1202 | ||
3544d72a | 1203 | if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) { |
aa9147c9 | 1204 | ret = ptrace_attach(child, request, addr, data); |
c269f196 RM |
1205 | /* |
1206 | * Some architectures need to do book-keeping after | |
1207 | * a ptrace attach. | |
1208 | */ | |
1209 | if (!ret) | |
1210 | arch_ptrace_attach(child); | |
1211 | goto out_put_task_struct; | |
1212 | } | |
1213 | ||
fca26f26 TH |
1214 | ret = ptrace_check_attach(child, request == PTRACE_KILL || |
1215 | request == PTRACE_INTERRUPT); | |
9899d11f | 1216 | if (!ret) { |
c269f196 | 1217 | ret = compat_arch_ptrace(child, request, addr, data); |
9899d11f ON |
1218 | if (ret || request != PTRACE_DETACH) |
1219 | ptrace_unfreeze_traced(child); | |
1220 | } | |
c269f196 RM |
1221 | |
1222 | out_put_task_struct: | |
1223 | put_task_struct(child); | |
1224 | out: | |
c269f196 RM |
1225 | return ret; |
1226 | } | |
96b8936a | 1227 | #endif /* CONFIG_COMPAT */ |
bf26c018 FW |
1228 | |
1229 | #ifdef CONFIG_HAVE_HW_BREAKPOINT | |
1230 | int ptrace_get_breakpoints(struct task_struct *tsk) | |
1231 | { | |
1232 | if (atomic_inc_not_zero(&tsk->ptrace_bp_refcnt)) | |
1233 | return 0; | |
1234 | ||
1235 | return -1; | |
1236 | } | |
1237 | ||
1238 | void ptrace_put_breakpoints(struct task_struct *tsk) | |
1239 | { | |
1240 | if (atomic_dec_and_test(&tsk->ptrace_bp_refcnt)) | |
1241 | flush_ptrace_hw_breakpoint(tsk); | |
1242 | } | |
1243 | #endif /* CONFIG_HAVE_HW_BREAKPOINT */ |