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 | |
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 | ||
0a5bf409 AN |
76 | clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); |
77 | ||
f470021a RM |
78 | child->parent = child->real_parent; |
79 | list_del_init(&child->ptrace_entry); | |
1da177e4 | 80 | |
1da177e4 | 81 | spin_lock(&child->sighand->siglock); |
1333ab03 | 82 | child->ptrace = 0; |
73ddff2b TH |
83 | /* |
84 | * Clear all pending traps and TRAPPING. TRAPPING should be | |
85 | * cleared regardless of JOBCTL_STOP_PENDING. Do it explicitly. | |
86 | */ | |
87 | task_clear_jobctl_pending(child, JOBCTL_TRAP_MASK); | |
88 | task_clear_jobctl_trapping(child); | |
89 | ||
0e9f0a4a | 90 | /* |
a8f072c1 | 91 | * Reinstate JOBCTL_STOP_PENDING if group stop is in effect and |
0e9f0a4a TH |
92 | * @child isn't dead. |
93 | */ | |
94 | if (!(child->flags & PF_EXITING) && | |
95 | (child->signal->flags & SIGNAL_STOP_STOPPED || | |
8a88951b | 96 | child->signal->group_stop_count)) { |
a8f072c1 | 97 | child->jobctl |= JOBCTL_STOP_PENDING; |
0e9f0a4a | 98 | |
8a88951b ON |
99 | /* |
100 | * This is only possible if this thread was cloned by the | |
101 | * traced task running in the stopped group, set the signal | |
102 | * for the future reports. | |
103 | * FIXME: we should change ptrace_init_task() to handle this | |
104 | * case. | |
105 | */ | |
106 | if (!(child->jobctl & JOBCTL_STOP_SIGMASK)) | |
107 | child->jobctl |= SIGSTOP; | |
108 | } | |
109 | ||
0e9f0a4a TH |
110 | /* |
111 | * If transition to TASK_STOPPED is pending or in TASK_TRACED, kick | |
112 | * @child in the butt. Note that @resume should be used iff @child | |
113 | * is in TASK_TRACED; otherwise, we might unduly disrupt | |
114 | * TASK_KILLABLE sleeps. | |
115 | */ | |
a8f072c1 | 116 | if (child->jobctl & JOBCTL_STOP_PENDING || task_is_traced(child)) |
910ffdb1 | 117 | ptrace_signal_wake_up(child, true); |
0e9f0a4a | 118 | |
1da177e4 | 119 | spin_unlock(&child->sighand->siglock); |
1da177e4 LT |
120 | } |
121 | ||
9899d11f ON |
122 | /* Ensure that nothing can wake it up, even SIGKILL */ |
123 | static bool ptrace_freeze_traced(struct task_struct *task) | |
124 | { | |
125 | bool ret = false; | |
126 | ||
127 | /* Lockless, nobody but us can set this flag */ | |
128 | if (task->jobctl & JOBCTL_LISTENING) | |
129 | return ret; | |
130 | ||
131 | spin_lock_irq(&task->sighand->siglock); | |
132 | if (task_is_traced(task) && !__fatal_signal_pending(task)) { | |
133 | task->state = __TASK_TRACED; | |
134 | ret = true; | |
135 | } | |
136 | spin_unlock_irq(&task->sighand->siglock); | |
137 | ||
138 | return ret; | |
139 | } | |
140 | ||
141 | static void ptrace_unfreeze_traced(struct task_struct *task) | |
142 | { | |
143 | if (task->state != __TASK_TRACED) | |
144 | return; | |
145 | ||
146 | WARN_ON(!task->ptrace || task->parent != current); | |
147 | ||
148 | spin_lock_irq(&task->sighand->siglock); | |
149 | if (__fatal_signal_pending(task)) | |
150 | wake_up_state(task, __TASK_TRACED); | |
151 | else | |
152 | task->state = TASK_TRACED; | |
153 | spin_unlock_irq(&task->sighand->siglock); | |
154 | } | |
155 | ||
755e276b TH |
156 | /** |
157 | * ptrace_check_attach - check whether ptracee is ready for ptrace operation | |
158 | * @child: ptracee to check for | |
159 | * @ignore_state: don't check whether @child is currently %TASK_TRACED | |
160 | * | |
161 | * Check whether @child is being ptraced by %current and ready for further | |
162 | * ptrace operations. If @ignore_state is %false, @child also should be in | |
163 | * %TASK_TRACED state and on return the child is guaranteed to be traced | |
164 | * and not executing. If @ignore_state is %true, @child can be in any | |
165 | * state. | |
166 | * | |
167 | * CONTEXT: | |
168 | * Grabs and releases tasklist_lock and @child->sighand->siglock. | |
169 | * | |
170 | * RETURNS: | |
171 | * 0 on success, -ESRCH if %child is not ready. | |
1da177e4 | 172 | */ |
edea0d03 | 173 | static int ptrace_check_attach(struct task_struct *child, bool ignore_state) |
1da177e4 LT |
174 | { |
175 | int ret = -ESRCH; | |
176 | ||
177 | /* | |
178 | * We take the read lock around doing both checks to close a | |
179 | * possible race where someone else was tracing our child and | |
180 | * detached between these two checks. After this locked check, | |
181 | * we are sure that this is our traced child and that can only | |
182 | * be changed by us so it's not changing right after this. | |
183 | */ | |
184 | read_lock(&tasklist_lock); | |
9899d11f ON |
185 | if (child->ptrace && child->parent == current) { |
186 | WARN_ON(child->state == __TASK_TRACED); | |
c0c0b649 ON |
187 | /* |
188 | * child->sighand can't be NULL, release_task() | |
189 | * does ptrace_unlink() before __exit_signal(). | |
190 | */ | |
9899d11f | 191 | if (ignore_state || ptrace_freeze_traced(child)) |
321fb561 | 192 | ret = 0; |
1da177e4 LT |
193 | } |
194 | read_unlock(&tasklist_lock); | |
195 | ||
9899d11f ON |
196 | if (!ret && !ignore_state) { |
197 | if (!wait_task_inactive(child, __TASK_TRACED)) { | |
198 | /* | |
199 | * This can only happen if may_ptrace_stop() fails and | |
200 | * ptrace_stop() changes ->state back to TASK_RUNNING, | |
201 | * so we should not worry about leaking __TASK_TRACED. | |
202 | */ | |
203 | WARN_ON(child->state == __TASK_TRACED); | |
204 | ret = -ESRCH; | |
205 | } | |
206 | } | |
1da177e4 | 207 | |
1da177e4 LT |
208 | return ret; |
209 | } | |
210 | ||
69f594a3 EP |
211 | static int ptrace_has_cap(struct user_namespace *ns, unsigned int mode) |
212 | { | |
213 | if (mode & PTRACE_MODE_NOAUDIT) | |
214 | return has_ns_capability_noaudit(current, ns, CAP_SYS_PTRACE); | |
215 | else | |
216 | return has_ns_capability(current, ns, CAP_SYS_PTRACE); | |
217 | } | |
218 | ||
9f99798f TH |
219 | /* Returns 0 on success, -errno on denial. */ |
220 | static int __ptrace_may_access(struct task_struct *task, unsigned int mode) | |
ab8d11be | 221 | { |
c69e8d9c | 222 | const struct cred *cred = current_cred(), *tcred; |
bfedb589 | 223 | struct mm_struct *mm; |
caaee623 JH |
224 | kuid_t caller_uid; |
225 | kgid_t caller_gid; | |
226 | ||
227 | if (!(mode & PTRACE_MODE_FSCREDS) == !(mode & PTRACE_MODE_REALCREDS)) { | |
228 | WARN(1, "denying ptrace access check without PTRACE_MODE_*CREDS\n"); | |
229 | return -EPERM; | |
230 | } | |
b6dff3ec | 231 | |
df26c40e EB |
232 | /* May we inspect the given task? |
233 | * This check is used both for attaching with ptrace | |
234 | * and for allowing access to sensitive information in /proc. | |
235 | * | |
236 | * ptrace_attach denies several cases that /proc allows | |
237 | * because setting up the necessary parent/child relationship | |
238 | * or halting the specified task is impossible. | |
239 | */ | |
caaee623 | 240 | |
df26c40e | 241 | /* Don't let security modules deny introspection */ |
73af963f | 242 | if (same_thread_group(task, current)) |
df26c40e | 243 | return 0; |
c69e8d9c | 244 | rcu_read_lock(); |
caaee623 JH |
245 | if (mode & PTRACE_MODE_FSCREDS) { |
246 | caller_uid = cred->fsuid; | |
247 | caller_gid = cred->fsgid; | |
248 | } else { | |
249 | /* | |
250 | * Using the euid would make more sense here, but something | |
251 | * in userland might rely on the old behavior, and this | |
252 | * shouldn't be a security problem since | |
253 | * PTRACE_MODE_REALCREDS implies that the caller explicitly | |
254 | * used a syscall that requests access to another process | |
255 | * (and not a filesystem syscall to procfs). | |
256 | */ | |
257 | caller_uid = cred->uid; | |
258 | caller_gid = cred->gid; | |
259 | } | |
c69e8d9c | 260 | tcred = __task_cred(task); |
caaee623 JH |
261 | if (uid_eq(caller_uid, tcred->euid) && |
262 | uid_eq(caller_uid, tcred->suid) && | |
263 | uid_eq(caller_uid, tcred->uid) && | |
264 | gid_eq(caller_gid, tcred->egid) && | |
265 | gid_eq(caller_gid, tcred->sgid) && | |
266 | gid_eq(caller_gid, tcred->gid)) | |
8409cca7 | 267 | goto ok; |
c4a4d603 | 268 | if (ptrace_has_cap(tcred->user_ns, mode)) |
8409cca7 SH |
269 | goto ok; |
270 | rcu_read_unlock(); | |
271 | return -EPERM; | |
272 | ok: | |
c69e8d9c | 273 | rcu_read_unlock(); |
bfedb589 EB |
274 | mm = task->mm; |
275 | if (mm && | |
276 | ((get_dumpable(mm) != SUID_DUMP_USER) && | |
277 | !ptrace_has_cap(mm->user_ns, mode))) | |
278 | return -EPERM; | |
ab8d11be | 279 | |
9e48858f | 280 | return security_ptrace_access_check(task, mode); |
ab8d11be MS |
281 | } |
282 | ||
006ebb40 | 283 | bool ptrace_may_access(struct task_struct *task, unsigned int mode) |
ab8d11be MS |
284 | { |
285 | int err; | |
286 | task_lock(task); | |
006ebb40 | 287 | err = __ptrace_may_access(task, mode); |
ab8d11be | 288 | task_unlock(task); |
3a709703 | 289 | return !err; |
ab8d11be MS |
290 | } |
291 | ||
3544d72a | 292 | static int ptrace_attach(struct task_struct *task, long request, |
aa9147c9 | 293 | unsigned long addr, |
3544d72a | 294 | unsigned long flags) |
1da177e4 | 295 | { |
3544d72a | 296 | bool seize = (request == PTRACE_SEIZE); |
1da177e4 | 297 | int retval; |
f5b40e36 | 298 | |
3544d72a | 299 | retval = -EIO; |
aa9147c9 DV |
300 | if (seize) { |
301 | if (addr != 0) | |
302 | goto out; | |
aa9147c9 DV |
303 | if (flags & ~(unsigned long)PTRACE_O_MASK) |
304 | goto out; | |
305 | flags = PT_PTRACED | PT_SEIZED | (flags << PT_OPT_FLAG_SHIFT); | |
306 | } else { | |
307 | flags = PT_PTRACED; | |
308 | } | |
3544d72a | 309 | |
a5cb013d AV |
310 | audit_ptrace(task); |
311 | ||
1da177e4 | 312 | retval = -EPERM; |
b79b7ba9 ON |
313 | if (unlikely(task->flags & PF_KTHREAD)) |
314 | goto out; | |
bac0abd6 | 315 | if (same_thread_group(task, current)) |
f5b40e36 LT |
316 | goto out; |
317 | ||
f2f0b00a ON |
318 | /* |
319 | * Protect exec's credential calculations against our interference; | |
86b6c1f3 | 320 | * SUID, SGID and LSM creds get determined differently |
5e751e99 | 321 | * under ptrace. |
d84f4f99 | 322 | */ |
793285fc | 323 | retval = -ERESTARTNOINTR; |
9b1bf12d | 324 | if (mutex_lock_interruptible(&task->signal->cred_guard_mutex)) |
d84f4f99 | 325 | goto out; |
f5b40e36 | 326 | |
4b105cbb | 327 | task_lock(task); |
caaee623 | 328 | retval = __ptrace_may_access(task, PTRACE_MODE_ATTACH_REALCREDS); |
bfedb589 EB |
329 | if (!retval) { |
330 | struct mm_struct *mm = task->mm; | |
331 | if (mm && ns_capable(mm->user_ns, CAP_SYS_PTRACE)) | |
332 | flags |= PT_PTRACE_CAP; | |
333 | } | |
4b105cbb | 334 | task_unlock(task); |
1da177e4 | 335 | if (retval) |
4b105cbb | 336 | goto unlock_creds; |
1da177e4 | 337 | |
4b105cbb | 338 | write_lock_irq(&tasklist_lock); |
b79b7ba9 ON |
339 | retval = -EPERM; |
340 | if (unlikely(task->exit_state)) | |
4b105cbb | 341 | goto unlock_tasklist; |
f2f0b00a | 342 | if (task->ptrace) |
4b105cbb | 343 | goto unlock_tasklist; |
b79b7ba9 | 344 | |
3544d72a | 345 | if (seize) |
aa9147c9 | 346 | flags |= PT_SEIZED; |
aa9147c9 | 347 | task->ptrace = flags; |
1da177e4 | 348 | |
1da177e4 | 349 | __ptrace_link(task, current); |
3544d72a TH |
350 | |
351 | /* SEIZE doesn't trap tracee on attach */ | |
352 | if (!seize) | |
353 | send_sig_info(SIGSTOP, SEND_SIG_FORCED, task); | |
b79b7ba9 | 354 | |
d79fdd6d TH |
355 | spin_lock(&task->sighand->siglock); |
356 | ||
357 | /* | |
73ddff2b | 358 | * If the task is already STOPPED, set JOBCTL_TRAP_STOP and |
d79fdd6d TH |
359 | * TRAPPING, and kick it so that it transits to TRACED. TRAPPING |
360 | * will be cleared if the child completes the transition or any | |
361 | * event which clears the group stop states happens. We'll wait | |
362 | * for the transition to complete before returning from this | |
363 | * function. | |
364 | * | |
365 | * This hides STOPPED -> RUNNING -> TRACED transition from the | |
366 | * attaching thread but a different thread in the same group can | |
367 | * still observe the transient RUNNING state. IOW, if another | |
368 | * thread's WNOHANG wait(2) on the stopped tracee races against | |
369 | * ATTACH, the wait(2) may fail due to the transient RUNNING. | |
370 | * | |
371 | * The following task_is_stopped() test is safe as both transitions | |
372 | * in and out of STOPPED are protected by siglock. | |
373 | */ | |
7dd3db54 | 374 | if (task_is_stopped(task) && |
73ddff2b | 375 | task_set_jobctl_pending(task, JOBCTL_TRAP_STOP | JOBCTL_TRAPPING)) |
910ffdb1 | 376 | signal_wake_up_state(task, __TASK_STOPPED); |
d79fdd6d TH |
377 | |
378 | spin_unlock(&task->sighand->siglock); | |
379 | ||
b79b7ba9 | 380 | retval = 0; |
4b105cbb ON |
381 | unlock_tasklist: |
382 | write_unlock_irq(&tasklist_lock); | |
383 | unlock_creds: | |
9b1bf12d | 384 | mutex_unlock(&task->signal->cred_guard_mutex); |
f5b40e36 | 385 | out: |
f701e5b7 | 386 | if (!retval) { |
7c3b00e0 ON |
387 | /* |
388 | * We do not bother to change retval or clear JOBCTL_TRAPPING | |
389 | * if wait_on_bit() was interrupted by SIGKILL. The tracer will | |
390 | * not return to user-mode, it will exit and clear this bit in | |
391 | * __ptrace_unlink() if it wasn't already cleared by the tracee; | |
392 | * and until then nobody can ptrace this task. | |
393 | */ | |
394 | wait_on_bit(&task->jobctl, JOBCTL_TRAPPING_BIT, TASK_KILLABLE); | |
f701e5b7 VZ |
395 | proc_ptrace_connector(task, PTRACE_ATTACH); |
396 | } | |
397 | ||
1da177e4 LT |
398 | return retval; |
399 | } | |
400 | ||
f2f0b00a ON |
401 | /** |
402 | * ptrace_traceme -- helper for PTRACE_TRACEME | |
403 | * | |
404 | * Performs checks and sets PT_PTRACED. | |
405 | * Should be used by all ptrace implementations for PTRACE_TRACEME. | |
406 | */ | |
e3e89cc5 | 407 | static int ptrace_traceme(void) |
f2f0b00a ON |
408 | { |
409 | int ret = -EPERM; | |
410 | ||
4b105cbb ON |
411 | write_lock_irq(&tasklist_lock); |
412 | /* Are we already being traced? */ | |
f2f0b00a | 413 | if (!current->ptrace) { |
f2f0b00a | 414 | ret = security_ptrace_traceme(current->parent); |
f2f0b00a ON |
415 | /* |
416 | * Check PF_EXITING to ensure ->real_parent has not passed | |
417 | * exit_ptrace(). Otherwise we don't report the error but | |
418 | * pretend ->real_parent untraces us right after return. | |
419 | */ | |
420 | if (!ret && !(current->real_parent->flags & PF_EXITING)) { | |
421 | current->ptrace = PT_PTRACED; | |
422 | __ptrace_link(current, current->real_parent); | |
423 | } | |
f2f0b00a | 424 | } |
4b105cbb ON |
425 | write_unlock_irq(&tasklist_lock); |
426 | ||
f2f0b00a ON |
427 | return ret; |
428 | } | |
429 | ||
39c626ae ON |
430 | /* |
431 | * Called with irqs disabled, returns true if childs should reap themselves. | |
432 | */ | |
433 | static int ignoring_children(struct sighand_struct *sigh) | |
434 | { | |
435 | int ret; | |
436 | spin_lock(&sigh->siglock); | |
437 | ret = (sigh->action[SIGCHLD-1].sa.sa_handler == SIG_IGN) || | |
438 | (sigh->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT); | |
439 | spin_unlock(&sigh->siglock); | |
440 | return ret; | |
441 | } | |
442 | ||
443 | /* | |
444 | * Called with tasklist_lock held for writing. | |
445 | * Unlink a traced task, and clean it up if it was a traced zombie. | |
446 | * Return true if it needs to be reaped with release_task(). | |
447 | * (We can't call release_task() here because we already hold tasklist_lock.) | |
448 | * | |
449 | * If it's a zombie, our attachedness prevented normal parent notification | |
450 | * or self-reaping. Do notification now if it would have happened earlier. | |
451 | * If it should reap itself, return true. | |
452 | * | |
a7f0765e ON |
453 | * If it's our own child, there is no notification to do. But if our normal |
454 | * children self-reap, then this child was prevented by ptrace and we must | |
455 | * reap it now, in that case we must also wake up sub-threads sleeping in | |
456 | * do_wait(). | |
39c626ae ON |
457 | */ |
458 | static bool __ptrace_detach(struct task_struct *tracer, struct task_struct *p) | |
459 | { | |
9843a1e9 ON |
460 | bool dead; |
461 | ||
39c626ae ON |
462 | __ptrace_unlink(p); |
463 | ||
9843a1e9 ON |
464 | if (p->exit_state != EXIT_ZOMBIE) |
465 | return false; | |
466 | ||
467 | dead = !thread_group_leader(p); | |
468 | ||
469 | if (!dead && thread_group_empty(p)) { | |
470 | if (!same_thread_group(p->real_parent, tracer)) | |
471 | dead = do_notify_parent(p, p->exit_signal); | |
472 | else if (ignoring_children(tracer->sighand)) { | |
473 | __wake_up_parent(p, tracer); | |
9843a1e9 | 474 | dead = true; |
39c626ae ON |
475 | } |
476 | } | |
9843a1e9 ON |
477 | /* Mark it as in the process of being reaped. */ |
478 | if (dead) | |
479 | p->exit_state = EXIT_DEAD; | |
480 | return dead; | |
39c626ae ON |
481 | } |
482 | ||
e3e89cc5 | 483 | static int ptrace_detach(struct task_struct *child, unsigned int data) |
1da177e4 | 484 | { |
7ed20e1a | 485 | if (!valid_signal(data)) |
5ecfbae0 | 486 | return -EIO; |
1da177e4 LT |
487 | |
488 | /* Architecture-specific hardware disable .. */ | |
489 | ptrace_disable(child); | |
490 | ||
95c3eb76 | 491 | write_lock_irq(&tasklist_lock); |
39c626ae | 492 | /* |
64a4096c ON |
493 | * We rely on ptrace_freeze_traced(). It can't be killed and |
494 | * untraced by another thread, it can't be a zombie. | |
39c626ae | 495 | */ |
64a4096c ON |
496 | WARN_ON(!child->ptrace || child->exit_state); |
497 | /* | |
498 | * tasklist_lock avoids the race with wait_task_stopped(), see | |
499 | * the comment in ptrace_resume(). | |
500 | */ | |
501 | child->exit_code = data; | |
502 | __ptrace_detach(current, child); | |
1da177e4 LT |
503 | write_unlock_irq(&tasklist_lock); |
504 | ||
f701e5b7 | 505 | proc_ptrace_connector(child, PTRACE_DETACH); |
4576145c | 506 | |
1da177e4 LT |
507 | return 0; |
508 | } | |
509 | ||
39c626ae | 510 | /* |
c7e49c14 | 511 | * Detach all tasks we were using ptrace on. Called with tasklist held |
7c8bd232 | 512 | * for writing. |
39c626ae | 513 | */ |
7c8bd232 | 514 | void exit_ptrace(struct task_struct *tracer, struct list_head *dead) |
39c626ae ON |
515 | { |
516 | struct task_struct *p, *n; | |
c7e49c14 | 517 | |
39c626ae | 518 | list_for_each_entry_safe(p, n, &tracer->ptraced, ptrace_entry) { |
992fb6e1 ON |
519 | if (unlikely(p->ptrace & PT_EXITKILL)) |
520 | send_sig_info(SIGKILL, SEND_SIG_FORCED, p); | |
521 | ||
39c626ae | 522 | if (__ptrace_detach(tracer, p)) |
7c8bd232 | 523 | list_add(&p->ptrace_entry, dead); |
39c626ae ON |
524 | } |
525 | } | |
526 | ||
1da177e4 LT |
527 | int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *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; | |
f307ab6d | 536 | retval = access_process_vm(tsk, src, buf, this_len, FOLL_FORCE); |
1da177e4 LT |
537 | if (!retval) { |
538 | if (copied) | |
539 | break; | |
540 | return -EIO; | |
541 | } | |
542 | if (copy_to_user(dst, buf, retval)) | |
543 | return -EFAULT; | |
544 | copied += retval; | |
545 | src += retval; | |
546 | dst += retval; | |
3a709703 | 547 | len -= retval; |
1da177e4 LT |
548 | } |
549 | return copied; | |
550 | } | |
551 | ||
552 | int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len) | |
553 | { | |
554 | int copied = 0; | |
555 | ||
556 | while (len > 0) { | |
557 | char buf[128]; | |
558 | int this_len, retval; | |
559 | ||
560 | this_len = (len > sizeof(buf)) ? sizeof(buf) : len; | |
561 | if (copy_from_user(buf, src, this_len)) | |
562 | return -EFAULT; | |
f307ab6d LS |
563 | retval = access_process_vm(tsk, dst, buf, this_len, |
564 | FOLL_FORCE | FOLL_WRITE); | |
1da177e4 LT |
565 | if (!retval) { |
566 | if (copied) | |
567 | break; | |
568 | return -EIO; | |
569 | } | |
570 | copied += retval; | |
571 | src += retval; | |
572 | dst += retval; | |
3a709703 | 573 | len -= retval; |
1da177e4 LT |
574 | } |
575 | return copied; | |
576 | } | |
577 | ||
4abf9869 | 578 | static int ptrace_setoptions(struct task_struct *child, unsigned long data) |
1da177e4 | 579 | { |
86b6c1f3 DV |
580 | unsigned flags; |
581 | ||
8c5cf9e5 DV |
582 | if (data & ~(unsigned long)PTRACE_O_MASK) |
583 | return -EINVAL; | |
584 | ||
13c4a901 | 585 | if (unlikely(data & PTRACE_O_SUSPEND_SECCOMP)) { |
97f2645f MY |
586 | if (!IS_ENABLED(CONFIG_CHECKPOINT_RESTORE) || |
587 | !IS_ENABLED(CONFIG_SECCOMP)) | |
13c4a901 TA |
588 | return -EINVAL; |
589 | ||
590 | if (!capable(CAP_SYS_ADMIN)) | |
591 | return -EPERM; | |
592 | ||
593 | if (seccomp_mode(¤t->seccomp) != SECCOMP_MODE_DISABLED || | |
594 | current->ptrace & PT_SUSPEND_SECCOMP) | |
595 | return -EPERM; | |
596 | } | |
597 | ||
86b6c1f3 DV |
598 | /* Avoid intermediate state when all opts are cleared */ |
599 | flags = child->ptrace; | |
600 | flags &= ~(PTRACE_O_MASK << PT_OPT_FLAG_SHIFT); | |
601 | flags |= (data << PT_OPT_FLAG_SHIFT); | |
602 | child->ptrace = flags; | |
1da177e4 | 603 | |
8c5cf9e5 | 604 | return 0; |
1da177e4 LT |
605 | } |
606 | ||
e16b2781 | 607 | static int ptrace_getsiginfo(struct task_struct *child, siginfo_t *info) |
1da177e4 | 608 | { |
e4961254 | 609 | unsigned long flags; |
1da177e4 LT |
610 | int error = -ESRCH; |
611 | ||
e4961254 | 612 | if (lock_task_sighand(child, &flags)) { |
1da177e4 | 613 | error = -EINVAL; |
1da177e4 | 614 | if (likely(child->last_siginfo != NULL)) { |
e16b2781 | 615 | *info = *child->last_siginfo; |
1da177e4 LT |
616 | error = 0; |
617 | } | |
e4961254 | 618 | unlock_task_sighand(child, &flags); |
1da177e4 | 619 | } |
1da177e4 LT |
620 | return error; |
621 | } | |
622 | ||
e16b2781 | 623 | static int ptrace_setsiginfo(struct task_struct *child, const siginfo_t *info) |
1da177e4 | 624 | { |
e4961254 | 625 | unsigned long flags; |
1da177e4 LT |
626 | int error = -ESRCH; |
627 | ||
e4961254 | 628 | if (lock_task_sighand(child, &flags)) { |
1da177e4 | 629 | error = -EINVAL; |
1da177e4 | 630 | if (likely(child->last_siginfo != NULL)) { |
e16b2781 | 631 | *child->last_siginfo = *info; |
1da177e4 LT |
632 | error = 0; |
633 | } | |
e4961254 | 634 | unlock_task_sighand(child, &flags); |
1da177e4 | 635 | } |
1da177e4 LT |
636 | return error; |
637 | } | |
638 | ||
84c751bd AV |
639 | static int ptrace_peek_siginfo(struct task_struct *child, |
640 | unsigned long addr, | |
641 | unsigned long data) | |
642 | { | |
643 | struct ptrace_peeksiginfo_args arg; | |
644 | struct sigpending *pending; | |
645 | struct sigqueue *q; | |
646 | int ret, i; | |
647 | ||
648 | ret = copy_from_user(&arg, (void __user *) addr, | |
649 | sizeof(struct ptrace_peeksiginfo_args)); | |
650 | if (ret) | |
651 | return -EFAULT; | |
652 | ||
653 | if (arg.flags & ~PTRACE_PEEKSIGINFO_SHARED) | |
654 | return -EINVAL; /* unknown flags */ | |
655 | ||
656 | if (arg.nr < 0) | |
657 | return -EINVAL; | |
658 | ||
659 | if (arg.flags & PTRACE_PEEKSIGINFO_SHARED) | |
660 | pending = &child->signal->shared_pending; | |
661 | else | |
662 | pending = &child->pending; | |
663 | ||
664 | for (i = 0; i < arg.nr; ) { | |
665 | siginfo_t info; | |
666 | s32 off = arg.off + i; | |
667 | ||
668 | spin_lock_irq(&child->sighand->siglock); | |
669 | list_for_each_entry(q, &pending->list, list) { | |
670 | if (!off--) { | |
671 | copy_siginfo(&info, &q->info); | |
672 | break; | |
673 | } | |
674 | } | |
675 | spin_unlock_irq(&child->sighand->siglock); | |
676 | ||
677 | if (off >= 0) /* beyond the end of the list */ | |
678 | break; | |
679 | ||
680 | #ifdef CONFIG_COMPAT | |
5c465217 | 681 | if (unlikely(in_compat_syscall())) { |
84c751bd AV |
682 | compat_siginfo_t __user *uinfo = compat_ptr(data); |
683 | ||
706b23bd MD |
684 | if (copy_siginfo_to_user32(uinfo, &info) || |
685 | __put_user(info.si_code, &uinfo->si_code)) { | |
686 | ret = -EFAULT; | |
687 | break; | |
688 | } | |
689 | ||
84c751bd AV |
690 | } else |
691 | #endif | |
692 | { | |
693 | siginfo_t __user *uinfo = (siginfo_t __user *) data; | |
694 | ||
706b23bd MD |
695 | if (copy_siginfo_to_user(uinfo, &info) || |
696 | __put_user(info.si_code, &uinfo->si_code)) { | |
697 | ret = -EFAULT; | |
698 | break; | |
699 | } | |
84c751bd AV |
700 | } |
701 | ||
702 | data += sizeof(siginfo_t); | |
703 | i++; | |
704 | ||
705 | if (signal_pending(current)) | |
706 | break; | |
707 | ||
708 | cond_resched(); | |
709 | } | |
710 | ||
711 | if (i > 0) | |
712 | return i; | |
713 | ||
714 | return ret; | |
715 | } | |
36df29d7 RM |
716 | |
717 | #ifdef PTRACE_SINGLESTEP | |
718 | #define is_singlestep(request) ((request) == PTRACE_SINGLESTEP) | |
719 | #else | |
720 | #define is_singlestep(request) 0 | |
721 | #endif | |
722 | ||
5b88abbf RM |
723 | #ifdef PTRACE_SINGLEBLOCK |
724 | #define is_singleblock(request) ((request) == PTRACE_SINGLEBLOCK) | |
725 | #else | |
726 | #define is_singleblock(request) 0 | |
727 | #endif | |
728 | ||
36df29d7 RM |
729 | #ifdef PTRACE_SYSEMU |
730 | #define is_sysemu_singlestep(request) ((request) == PTRACE_SYSEMU_SINGLESTEP) | |
731 | #else | |
732 | #define is_sysemu_singlestep(request) 0 | |
733 | #endif | |
734 | ||
4abf9869 NK |
735 | static int ptrace_resume(struct task_struct *child, long request, |
736 | unsigned long data) | |
36df29d7 | 737 | { |
b72c1869 ON |
738 | bool need_siglock; |
739 | ||
36df29d7 RM |
740 | if (!valid_signal(data)) |
741 | return -EIO; | |
742 | ||
743 | if (request == PTRACE_SYSCALL) | |
744 | set_tsk_thread_flag(child, TIF_SYSCALL_TRACE); | |
745 | else | |
746 | clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); | |
747 | ||
748 | #ifdef TIF_SYSCALL_EMU | |
749 | if (request == PTRACE_SYSEMU || request == PTRACE_SYSEMU_SINGLESTEP) | |
750 | set_tsk_thread_flag(child, TIF_SYSCALL_EMU); | |
751 | else | |
752 | clear_tsk_thread_flag(child, TIF_SYSCALL_EMU); | |
753 | #endif | |
754 | ||
5b88abbf RM |
755 | if (is_singleblock(request)) { |
756 | if (unlikely(!arch_has_block_step())) | |
757 | return -EIO; | |
758 | user_enable_block_step(child); | |
759 | } else if (is_singlestep(request) || is_sysemu_singlestep(request)) { | |
36df29d7 RM |
760 | if (unlikely(!arch_has_single_step())) |
761 | return -EIO; | |
762 | user_enable_single_step(child); | |
3a709703 | 763 | } else { |
36df29d7 | 764 | user_disable_single_step(child); |
3a709703 | 765 | } |
36df29d7 | 766 | |
b72c1869 ON |
767 | /* |
768 | * Change ->exit_code and ->state under siglock to avoid the race | |
769 | * with wait_task_stopped() in between; a non-zero ->exit_code will | |
770 | * wrongly look like another report from tracee. | |
771 | * | |
772 | * Note that we need siglock even if ->exit_code == data and/or this | |
773 | * status was not reported yet, the new status must not be cleared by | |
774 | * wait_task_stopped() after resume. | |
775 | * | |
776 | * If data == 0 we do not care if wait_task_stopped() reports the old | |
777 | * status and clears the code too; this can't race with the tracee, it | |
778 | * takes siglock after resume. | |
779 | */ | |
780 | need_siglock = data && !thread_group_empty(current); | |
781 | if (need_siglock) | |
782 | spin_lock_irq(&child->sighand->siglock); | |
36df29d7 | 783 | child->exit_code = data; |
0666fb51 | 784 | wake_up_state(child, __TASK_TRACED); |
b72c1869 ON |
785 | if (need_siglock) |
786 | spin_unlock_irq(&child->sighand->siglock); | |
36df29d7 RM |
787 | |
788 | return 0; | |
789 | } | |
790 | ||
2225a122 SS |
791 | #ifdef CONFIG_HAVE_ARCH_TRACEHOOK |
792 | ||
793 | static const struct user_regset * | |
794 | find_regset(const struct user_regset_view *view, unsigned int type) | |
795 | { | |
796 | const struct user_regset *regset; | |
797 | int n; | |
798 | ||
799 | for (n = 0; n < view->n; ++n) { | |
800 | regset = view->regsets + n; | |
801 | if (regset->core_note_type == type) | |
802 | return regset; | |
803 | } | |
804 | ||
805 | return NULL; | |
806 | } | |
807 | ||
808 | static int ptrace_regset(struct task_struct *task, int req, unsigned int type, | |
809 | struct iovec *kiov) | |
810 | { | |
811 | const struct user_regset_view *view = task_user_regset_view(task); | |
812 | const struct user_regset *regset = find_regset(view, type); | |
813 | int regset_no; | |
814 | ||
815 | if (!regset || (kiov->iov_len % regset->size) != 0) | |
c6a0dd7e | 816 | return -EINVAL; |
2225a122 SS |
817 | |
818 | regset_no = regset - view->regsets; | |
819 | kiov->iov_len = min(kiov->iov_len, | |
820 | (__kernel_size_t) (regset->n * regset->size)); | |
821 | ||
822 | if (req == PTRACE_GETREGSET) | |
823 | return copy_regset_to_user(task, view, regset_no, 0, | |
824 | kiov->iov_len, kiov->iov_base); | |
825 | else | |
826 | return copy_regset_from_user(task, view, regset_no, 0, | |
827 | kiov->iov_len, kiov->iov_base); | |
828 | } | |
829 | ||
e8440c14 JS |
830 | /* |
831 | * This is declared in linux/regset.h and defined in machine-dependent | |
832 | * code. We put the export here, near the primary machine-neutral use, | |
833 | * to ensure no machine forgets it. | |
834 | */ | |
835 | EXPORT_SYMBOL_GPL(task_user_regset_view); | |
2225a122 SS |
836 | #endif |
837 | ||
1da177e4 | 838 | int ptrace_request(struct task_struct *child, long request, |
4abf9869 | 839 | unsigned long addr, unsigned long data) |
1da177e4 | 840 | { |
fca26f26 | 841 | bool seized = child->ptrace & PT_SEIZED; |
1da177e4 | 842 | int ret = -EIO; |
544b2c91 | 843 | siginfo_t siginfo, *si; |
9fed81dc NK |
844 | void __user *datavp = (void __user *) data; |
845 | unsigned long __user *datalp = datavp; | |
fca26f26 | 846 | unsigned long flags; |
1da177e4 LT |
847 | |
848 | switch (request) { | |
16c3e389 RM |
849 | case PTRACE_PEEKTEXT: |
850 | case PTRACE_PEEKDATA: | |
851 | return generic_ptrace_peekdata(child, addr, data); | |
852 | case PTRACE_POKETEXT: | |
853 | case PTRACE_POKEDATA: | |
854 | return generic_ptrace_pokedata(child, addr, data); | |
855 | ||
1da177e4 LT |
856 | #ifdef PTRACE_OLDSETOPTIONS |
857 | case PTRACE_OLDSETOPTIONS: | |
858 | #endif | |
859 | case PTRACE_SETOPTIONS: | |
860 | ret = ptrace_setoptions(child, data); | |
861 | break; | |
862 | case PTRACE_GETEVENTMSG: | |
9fed81dc | 863 | ret = put_user(child->ptrace_message, datalp); |
1da177e4 | 864 | break; |
e16b2781 | 865 | |
84c751bd AV |
866 | case PTRACE_PEEKSIGINFO: |
867 | ret = ptrace_peek_siginfo(child, addr, data); | |
868 | break; | |
869 | ||
1da177e4 | 870 | case PTRACE_GETSIGINFO: |
e16b2781 RM |
871 | ret = ptrace_getsiginfo(child, &siginfo); |
872 | if (!ret) | |
9fed81dc | 873 | ret = copy_siginfo_to_user(datavp, &siginfo); |
1da177e4 | 874 | break; |
e16b2781 | 875 | |
1da177e4 | 876 | case PTRACE_SETSIGINFO: |
9fed81dc | 877 | if (copy_from_user(&siginfo, datavp, sizeof siginfo)) |
e16b2781 RM |
878 | ret = -EFAULT; |
879 | else | |
880 | ret = ptrace_setsiginfo(child, &siginfo); | |
1da177e4 | 881 | break; |
e16b2781 | 882 | |
29000cae AV |
883 | case PTRACE_GETSIGMASK: |
884 | if (addr != sizeof(sigset_t)) { | |
885 | ret = -EINVAL; | |
886 | break; | |
887 | } | |
888 | ||
889 | if (copy_to_user(datavp, &child->blocked, sizeof(sigset_t))) | |
890 | ret = -EFAULT; | |
891 | else | |
892 | ret = 0; | |
893 | ||
894 | break; | |
895 | ||
896 | case PTRACE_SETSIGMASK: { | |
897 | sigset_t new_set; | |
898 | ||
899 | if (addr != sizeof(sigset_t)) { | |
900 | ret = -EINVAL; | |
901 | break; | |
902 | } | |
903 | ||
904 | if (copy_from_user(&new_set, datavp, sizeof(sigset_t))) { | |
905 | ret = -EFAULT; | |
906 | break; | |
907 | } | |
908 | ||
909 | sigdelsetmask(&new_set, sigmask(SIGKILL)|sigmask(SIGSTOP)); | |
910 | ||
911 | /* | |
912 | * Every thread does recalc_sigpending() after resume, so | |
913 | * retarget_shared_pending() and recalc_sigpending() are not | |
914 | * called here. | |
915 | */ | |
916 | spin_lock_irq(&child->sighand->siglock); | |
917 | child->blocked = new_set; | |
918 | spin_unlock_irq(&child->sighand->siglock); | |
919 | ||
920 | ret = 0; | |
921 | break; | |
922 | } | |
923 | ||
fca26f26 TH |
924 | case PTRACE_INTERRUPT: |
925 | /* | |
926 | * Stop tracee without any side-effect on signal or job | |
927 | * control. At least one trap is guaranteed to happen | |
928 | * after this request. If @child is already trapped, the | |
929 | * current trap is not disturbed and another trap will | |
930 | * happen after the current trap is ended with PTRACE_CONT. | |
931 | * | |
932 | * The actual trap might not be PTRACE_EVENT_STOP trap but | |
933 | * the pending condition is cleared regardless. | |
934 | */ | |
935 | if (unlikely(!seized || !lock_task_sighand(child, &flags))) | |
936 | break; | |
937 | ||
544b2c91 TH |
938 | /* |
939 | * INTERRUPT doesn't disturb existing trap sans one | |
940 | * exception. If ptracer issued LISTEN for the current | |
941 | * STOP, this INTERRUPT should clear LISTEN and re-trap | |
942 | * tracee into STOP. | |
943 | */ | |
fca26f26 | 944 | if (likely(task_set_jobctl_pending(child, JOBCTL_TRAP_STOP))) |
910ffdb1 | 945 | ptrace_signal_wake_up(child, child->jobctl & JOBCTL_LISTENING); |
544b2c91 TH |
946 | |
947 | unlock_task_sighand(child, &flags); | |
948 | ret = 0; | |
949 | break; | |
950 | ||
951 | case PTRACE_LISTEN: | |
952 | /* | |
953 | * Listen for events. Tracee must be in STOP. It's not | |
954 | * resumed per-se but is not considered to be in TRACED by | |
955 | * wait(2) or ptrace(2). If an async event (e.g. group | |
956 | * stop state change) happens, tracee will enter STOP trap | |
957 | * again. Alternatively, ptracer can issue INTERRUPT to | |
958 | * finish listening and re-trap tracee into STOP. | |
959 | */ | |
960 | if (unlikely(!seized || !lock_task_sighand(child, &flags))) | |
961 | break; | |
962 | ||
963 | si = child->last_siginfo; | |
f9d81f61 ON |
964 | if (likely(si && (si->si_code >> 8) == PTRACE_EVENT_STOP)) { |
965 | child->jobctl |= JOBCTL_LISTENING; | |
966 | /* | |
967 | * If NOTIFY is set, it means event happened between | |
968 | * start of this trap and now. Trigger re-trap. | |
969 | */ | |
970 | if (child->jobctl & JOBCTL_TRAP_NOTIFY) | |
910ffdb1 | 971 | ptrace_signal_wake_up(child, true); |
f9d81f61 ON |
972 | ret = 0; |
973 | } | |
fca26f26 | 974 | unlock_task_sighand(child, &flags); |
fca26f26 TH |
975 | break; |
976 | ||
1bcf5482 AD |
977 | case PTRACE_DETACH: /* detach a process that was attached. */ |
978 | ret = ptrace_detach(child, data); | |
979 | break; | |
36df29d7 | 980 | |
9c1a1259 MF |
981 | #ifdef CONFIG_BINFMT_ELF_FDPIC |
982 | case PTRACE_GETFDPIC: { | |
e0129ef9 | 983 | struct mm_struct *mm = get_task_mm(child); |
9c1a1259 MF |
984 | unsigned long tmp = 0; |
985 | ||
e0129ef9 ON |
986 | ret = -ESRCH; |
987 | if (!mm) | |
988 | break; | |
989 | ||
9c1a1259 MF |
990 | switch (addr) { |
991 | case PTRACE_GETFDPIC_EXEC: | |
e0129ef9 | 992 | tmp = mm->context.exec_fdpic_loadmap; |
9c1a1259 MF |
993 | break; |
994 | case PTRACE_GETFDPIC_INTERP: | |
e0129ef9 | 995 | tmp = mm->context.interp_fdpic_loadmap; |
9c1a1259 MF |
996 | break; |
997 | default: | |
998 | break; | |
999 | } | |
e0129ef9 | 1000 | mmput(mm); |
9c1a1259 | 1001 | |
9fed81dc | 1002 | ret = put_user(tmp, datalp); |
9c1a1259 MF |
1003 | break; |
1004 | } | |
1005 | #endif | |
1006 | ||
36df29d7 RM |
1007 | #ifdef PTRACE_SINGLESTEP |
1008 | case PTRACE_SINGLESTEP: | |
1009 | #endif | |
5b88abbf RM |
1010 | #ifdef PTRACE_SINGLEBLOCK |
1011 | case PTRACE_SINGLEBLOCK: | |
1012 | #endif | |
36df29d7 RM |
1013 | #ifdef PTRACE_SYSEMU |
1014 | case PTRACE_SYSEMU: | |
1015 | case PTRACE_SYSEMU_SINGLESTEP: | |
1016 | #endif | |
1017 | case PTRACE_SYSCALL: | |
1018 | case PTRACE_CONT: | |
1019 | return ptrace_resume(child, request, data); | |
1020 | ||
1021 | case PTRACE_KILL: | |
1022 | if (child->exit_state) /* already dead */ | |
1023 | return 0; | |
1024 | return ptrace_resume(child, request, SIGKILL); | |
1025 | ||
2225a122 SS |
1026 | #ifdef CONFIG_HAVE_ARCH_TRACEHOOK |
1027 | case PTRACE_GETREGSET: | |
29000cae | 1028 | case PTRACE_SETREGSET: { |
2225a122 | 1029 | struct iovec kiov; |
9fed81dc | 1030 | struct iovec __user *uiov = datavp; |
2225a122 SS |
1031 | |
1032 | if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov))) | |
1033 | return -EFAULT; | |
1034 | ||
1035 | if (__get_user(kiov.iov_base, &uiov->iov_base) || | |
1036 | __get_user(kiov.iov_len, &uiov->iov_len)) | |
1037 | return -EFAULT; | |
1038 | ||
1039 | ret = ptrace_regset(child, request, addr, &kiov); | |
1040 | if (!ret) | |
1041 | ret = __put_user(kiov.iov_len, &uiov->iov_len); | |
1042 | break; | |
1043 | } | |
1044 | #endif | |
f8e529ed TA |
1045 | |
1046 | case PTRACE_SECCOMP_GET_FILTER: | |
1047 | ret = seccomp_get_filter(child, addr, datavp); | |
1048 | break; | |
1049 | ||
1da177e4 LT |
1050 | default: |
1051 | break; | |
1052 | } | |
1053 | ||
1054 | return ret; | |
1055 | } | |
481bed45 | 1056 | |
8053bdd5 | 1057 | static struct task_struct *ptrace_get_task_struct(pid_t pid) |
6b9c7ed8 CH |
1058 | { |
1059 | struct task_struct *child; | |
481bed45 | 1060 | |
8053bdd5 | 1061 | rcu_read_lock(); |
228ebcbe | 1062 | child = find_task_by_vpid(pid); |
481bed45 CH |
1063 | if (child) |
1064 | get_task_struct(child); | |
8053bdd5 | 1065 | rcu_read_unlock(); |
f400e198 | 1066 | |
481bed45 | 1067 | if (!child) |
6b9c7ed8 CH |
1068 | return ERR_PTR(-ESRCH); |
1069 | return child; | |
481bed45 CH |
1070 | } |
1071 | ||
0ac15559 CH |
1072 | #ifndef arch_ptrace_attach |
1073 | #define arch_ptrace_attach(child) do { } while (0) | |
1074 | #endif | |
1075 | ||
4abf9869 NK |
1076 | SYSCALL_DEFINE4(ptrace, long, request, long, pid, unsigned long, addr, |
1077 | unsigned long, data) | |
481bed45 CH |
1078 | { |
1079 | struct task_struct *child; | |
1080 | long ret; | |
1081 | ||
6b9c7ed8 CH |
1082 | if (request == PTRACE_TRACEME) { |
1083 | ret = ptrace_traceme(); | |
6ea6dd93 HS |
1084 | if (!ret) |
1085 | arch_ptrace_attach(current); | |
481bed45 | 1086 | goto out; |
6b9c7ed8 CH |
1087 | } |
1088 | ||
1089 | child = ptrace_get_task_struct(pid); | |
1090 | if (IS_ERR(child)) { | |
1091 | ret = PTR_ERR(child); | |
1092 | goto out; | |
1093 | } | |
481bed45 | 1094 | |
3544d72a | 1095 | if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) { |
aa9147c9 | 1096 | ret = ptrace_attach(child, request, addr, data); |
0ac15559 CH |
1097 | /* |
1098 | * Some architectures need to do book-keeping after | |
1099 | * a ptrace attach. | |
1100 | */ | |
1101 | if (!ret) | |
1102 | arch_ptrace_attach(child); | |
005f18df | 1103 | goto out_put_task_struct; |
481bed45 CH |
1104 | } |
1105 | ||
fca26f26 TH |
1106 | ret = ptrace_check_attach(child, request == PTRACE_KILL || |
1107 | request == PTRACE_INTERRUPT); | |
481bed45 CH |
1108 | if (ret < 0) |
1109 | goto out_put_task_struct; | |
1110 | ||
1111 | ret = arch_ptrace(child, request, addr, data); | |
9899d11f ON |
1112 | if (ret || request != PTRACE_DETACH) |
1113 | ptrace_unfreeze_traced(child); | |
481bed45 CH |
1114 | |
1115 | out_put_task_struct: | |
1116 | put_task_struct(child); | |
1117 | out: | |
481bed45 CH |
1118 | return ret; |
1119 | } | |
76647323 | 1120 | |
4abf9869 NK |
1121 | int generic_ptrace_peekdata(struct task_struct *tsk, unsigned long addr, |
1122 | unsigned long data) | |
76647323 AD |
1123 | { |
1124 | unsigned long tmp; | |
1125 | int copied; | |
1126 | ||
f307ab6d | 1127 | copied = access_process_vm(tsk, addr, &tmp, sizeof(tmp), FOLL_FORCE); |
76647323 AD |
1128 | if (copied != sizeof(tmp)) |
1129 | return -EIO; | |
1130 | return put_user(tmp, (unsigned long __user *)data); | |
1131 | } | |
f284ce72 | 1132 | |
4abf9869 NK |
1133 | int generic_ptrace_pokedata(struct task_struct *tsk, unsigned long addr, |
1134 | unsigned long data) | |
f284ce72 AD |
1135 | { |
1136 | int copied; | |
1137 | ||
f307ab6d LS |
1138 | copied = access_process_vm(tsk, addr, &data, sizeof(data), |
1139 | FOLL_FORCE | FOLL_WRITE); | |
f284ce72 AD |
1140 | return (copied == sizeof(data)) ? 0 : -EIO; |
1141 | } | |
032d82d9 | 1142 | |
96b8936a | 1143 | #if defined CONFIG_COMPAT |
032d82d9 RM |
1144 | |
1145 | int compat_ptrace_request(struct task_struct *child, compat_long_t request, | |
1146 | compat_ulong_t addr, compat_ulong_t data) | |
1147 | { | |
1148 | compat_ulong_t __user *datap = compat_ptr(data); | |
1149 | compat_ulong_t word; | |
e16b2781 | 1150 | siginfo_t siginfo; |
032d82d9 RM |
1151 | int ret; |
1152 | ||
1153 | switch (request) { | |
1154 | case PTRACE_PEEKTEXT: | |
1155 | case PTRACE_PEEKDATA: | |
f307ab6d LS |
1156 | ret = access_process_vm(child, addr, &word, sizeof(word), |
1157 | FOLL_FORCE); | |
032d82d9 RM |
1158 | if (ret != sizeof(word)) |
1159 | ret = -EIO; | |
1160 | else | |
1161 | ret = put_user(word, datap); | |
1162 | break; | |
1163 | ||
1164 | case PTRACE_POKETEXT: | |
1165 | case PTRACE_POKEDATA: | |
f307ab6d LS |
1166 | ret = access_process_vm(child, addr, &data, sizeof(data), |
1167 | FOLL_FORCE | FOLL_WRITE); | |
032d82d9 RM |
1168 | ret = (ret != sizeof(data) ? -EIO : 0); |
1169 | break; | |
1170 | ||
1171 | case PTRACE_GETEVENTMSG: | |
1172 | ret = put_user((compat_ulong_t) child->ptrace_message, datap); | |
1173 | break; | |
1174 | ||
e16b2781 RM |
1175 | case PTRACE_GETSIGINFO: |
1176 | ret = ptrace_getsiginfo(child, &siginfo); | |
1177 | if (!ret) | |
1178 | ret = copy_siginfo_to_user32( | |
1179 | (struct compat_siginfo __user *) datap, | |
1180 | &siginfo); | |
1181 | break; | |
1182 | ||
1183 | case PTRACE_SETSIGINFO: | |
1184 | memset(&siginfo, 0, sizeof siginfo); | |
1185 | if (copy_siginfo_from_user32( | |
1186 | &siginfo, (struct compat_siginfo __user *) datap)) | |
1187 | ret = -EFAULT; | |
1188 | else | |
1189 | ret = ptrace_setsiginfo(child, &siginfo); | |
1190 | break; | |
2225a122 SS |
1191 | #ifdef CONFIG_HAVE_ARCH_TRACEHOOK |
1192 | case PTRACE_GETREGSET: | |
1193 | case PTRACE_SETREGSET: | |
1194 | { | |
1195 | struct iovec kiov; | |
1196 | struct compat_iovec __user *uiov = | |
1197 | (struct compat_iovec __user *) datap; | |
1198 | compat_uptr_t ptr; | |
1199 | compat_size_t len; | |
1200 | ||
1201 | if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov))) | |
1202 | return -EFAULT; | |
1203 | ||
1204 | if (__get_user(ptr, &uiov->iov_base) || | |
1205 | __get_user(len, &uiov->iov_len)) | |
1206 | return -EFAULT; | |
1207 | ||
1208 | kiov.iov_base = compat_ptr(ptr); | |
1209 | kiov.iov_len = len; | |
1210 | ||
1211 | ret = ptrace_regset(child, request, addr, &kiov); | |
1212 | if (!ret) | |
1213 | ret = __put_user(kiov.iov_len, &uiov->iov_len); | |
1214 | break; | |
1215 | } | |
1216 | #endif | |
e16b2781 | 1217 | |
032d82d9 RM |
1218 | default: |
1219 | ret = ptrace_request(child, request, addr, data); | |
1220 | } | |
1221 | ||
1222 | return ret; | |
1223 | } | |
c269f196 | 1224 | |
62a6fa97 HC |
1225 | COMPAT_SYSCALL_DEFINE4(ptrace, compat_long_t, request, compat_long_t, pid, |
1226 | compat_long_t, addr, compat_long_t, data) | |
c269f196 RM |
1227 | { |
1228 | struct task_struct *child; | |
1229 | long ret; | |
1230 | ||
c269f196 RM |
1231 | if (request == PTRACE_TRACEME) { |
1232 | ret = ptrace_traceme(); | |
1233 | goto out; | |
1234 | } | |
1235 | ||
1236 | child = ptrace_get_task_struct(pid); | |
1237 | if (IS_ERR(child)) { | |
1238 | ret = PTR_ERR(child); | |
1239 | goto out; | |
1240 | } | |
1241 | ||
3544d72a | 1242 | if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) { |
aa9147c9 | 1243 | ret = ptrace_attach(child, request, addr, data); |
c269f196 RM |
1244 | /* |
1245 | * Some architectures need to do book-keeping after | |
1246 | * a ptrace attach. | |
1247 | */ | |
1248 | if (!ret) | |
1249 | arch_ptrace_attach(child); | |
1250 | goto out_put_task_struct; | |
1251 | } | |
1252 | ||
fca26f26 TH |
1253 | ret = ptrace_check_attach(child, request == PTRACE_KILL || |
1254 | request == PTRACE_INTERRUPT); | |
9899d11f | 1255 | if (!ret) { |
c269f196 | 1256 | ret = compat_arch_ptrace(child, request, addr, data); |
9899d11f ON |
1257 | if (ret || request != PTRACE_DETACH) |
1258 | ptrace_unfreeze_traced(child); | |
1259 | } | |
c269f196 RM |
1260 | |
1261 | out_put_task_struct: | |
1262 | put_task_struct(child); | |
1263 | out: | |
c269f196 RM |
1264 | return ret; |
1265 | } | |
96b8936a | 1266 | #endif /* CONFIG_COMPAT */ |