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 | ||
f470021a RM |
76 | child->parent = child->real_parent; |
77 | list_del_init(&child->ptrace_entry); | |
1da177e4 | 78 | |
1da177e4 | 79 | spin_lock(&child->sighand->siglock); |
1333ab03 | 80 | child->ptrace = 0; |
73ddff2b TH |
81 | /* |
82 | * Clear all pending traps and TRAPPING. TRAPPING should be | |
83 | * cleared regardless of JOBCTL_STOP_PENDING. Do it explicitly. | |
84 | */ | |
85 | task_clear_jobctl_pending(child, JOBCTL_TRAP_MASK); | |
86 | task_clear_jobctl_trapping(child); | |
87 | ||
0e9f0a4a | 88 | /* |
a8f072c1 | 89 | * Reinstate JOBCTL_STOP_PENDING if group stop is in effect and |
0e9f0a4a TH |
90 | * @child isn't dead. |
91 | */ | |
92 | if (!(child->flags & PF_EXITING) && | |
93 | (child->signal->flags & SIGNAL_STOP_STOPPED || | |
8a88951b | 94 | child->signal->group_stop_count)) { |
a8f072c1 | 95 | child->jobctl |= JOBCTL_STOP_PENDING; |
0e9f0a4a | 96 | |
8a88951b ON |
97 | /* |
98 | * This is only possible if this thread was cloned by the | |
99 | * traced task running in the stopped group, set the signal | |
100 | * for the future reports. | |
101 | * FIXME: we should change ptrace_init_task() to handle this | |
102 | * case. | |
103 | */ | |
104 | if (!(child->jobctl & JOBCTL_STOP_SIGMASK)) | |
105 | child->jobctl |= SIGSTOP; | |
106 | } | |
107 | ||
0e9f0a4a TH |
108 | /* |
109 | * If transition to TASK_STOPPED is pending or in TASK_TRACED, kick | |
110 | * @child in the butt. Note that @resume should be used iff @child | |
111 | * is in TASK_TRACED; otherwise, we might unduly disrupt | |
112 | * TASK_KILLABLE sleeps. | |
113 | */ | |
a8f072c1 | 114 | if (child->jobctl & JOBCTL_STOP_PENDING || task_is_traced(child)) |
910ffdb1 | 115 | ptrace_signal_wake_up(child, true); |
0e9f0a4a | 116 | |
1da177e4 | 117 | spin_unlock(&child->sighand->siglock); |
1da177e4 LT |
118 | } |
119 | ||
9899d11f ON |
120 | /* Ensure that nothing can wake it up, even SIGKILL */ |
121 | static bool ptrace_freeze_traced(struct task_struct *task) | |
122 | { | |
123 | bool ret = false; | |
124 | ||
125 | /* Lockless, nobody but us can set this flag */ | |
126 | if (task->jobctl & JOBCTL_LISTENING) | |
127 | return ret; | |
128 | ||
129 | spin_lock_irq(&task->sighand->siglock); | |
130 | if (task_is_traced(task) && !__fatal_signal_pending(task)) { | |
131 | task->state = __TASK_TRACED; | |
132 | ret = true; | |
133 | } | |
134 | spin_unlock_irq(&task->sighand->siglock); | |
135 | ||
136 | return ret; | |
137 | } | |
138 | ||
139 | static void ptrace_unfreeze_traced(struct task_struct *task) | |
140 | { | |
141 | if (task->state != __TASK_TRACED) | |
142 | return; | |
143 | ||
144 | WARN_ON(!task->ptrace || task->parent != current); | |
145 | ||
146 | spin_lock_irq(&task->sighand->siglock); | |
147 | if (__fatal_signal_pending(task)) | |
148 | wake_up_state(task, __TASK_TRACED); | |
149 | else | |
150 | task->state = TASK_TRACED; | |
151 | spin_unlock_irq(&task->sighand->siglock); | |
152 | } | |
153 | ||
755e276b TH |
154 | /** |
155 | * ptrace_check_attach - check whether ptracee is ready for ptrace operation | |
156 | * @child: ptracee to check for | |
157 | * @ignore_state: don't check whether @child is currently %TASK_TRACED | |
158 | * | |
159 | * Check whether @child is being ptraced by %current and ready for further | |
160 | * ptrace operations. If @ignore_state is %false, @child also should be in | |
161 | * %TASK_TRACED state and on return the child is guaranteed to be traced | |
162 | * and not executing. If @ignore_state is %true, @child can be in any | |
163 | * state. | |
164 | * | |
165 | * CONTEXT: | |
166 | * Grabs and releases tasklist_lock and @child->sighand->siglock. | |
167 | * | |
168 | * RETURNS: | |
169 | * 0 on success, -ESRCH if %child is not ready. | |
1da177e4 | 170 | */ |
edea0d03 | 171 | static int ptrace_check_attach(struct task_struct *child, bool ignore_state) |
1da177e4 LT |
172 | { |
173 | int ret = -ESRCH; | |
174 | ||
175 | /* | |
176 | * We take the read lock around doing both checks to close a | |
177 | * possible race where someone else was tracing our child and | |
178 | * detached between these two checks. After this locked check, | |
179 | * we are sure that this is our traced child and that can only | |
180 | * be changed by us so it's not changing right after this. | |
181 | */ | |
182 | read_lock(&tasklist_lock); | |
9899d11f ON |
183 | if (child->ptrace && child->parent == current) { |
184 | WARN_ON(child->state == __TASK_TRACED); | |
c0c0b649 ON |
185 | /* |
186 | * child->sighand can't be NULL, release_task() | |
187 | * does ptrace_unlink() before __exit_signal(). | |
188 | */ | |
9899d11f | 189 | if (ignore_state || ptrace_freeze_traced(child)) |
321fb561 | 190 | ret = 0; |
1da177e4 LT |
191 | } |
192 | read_unlock(&tasklist_lock); | |
193 | ||
9899d11f ON |
194 | if (!ret && !ignore_state) { |
195 | if (!wait_task_inactive(child, __TASK_TRACED)) { | |
196 | /* | |
197 | * This can only happen if may_ptrace_stop() fails and | |
198 | * ptrace_stop() changes ->state back to TASK_RUNNING, | |
199 | * so we should not worry about leaking __TASK_TRACED. | |
200 | */ | |
201 | WARN_ON(child->state == __TASK_TRACED); | |
202 | ret = -ESRCH; | |
203 | } | |
204 | } | |
1da177e4 | 205 | |
1da177e4 LT |
206 | return ret; |
207 | } | |
208 | ||
69f594a3 EP |
209 | static int ptrace_has_cap(struct user_namespace *ns, unsigned int mode) |
210 | { | |
211 | if (mode & PTRACE_MODE_NOAUDIT) | |
212 | return has_ns_capability_noaudit(current, ns, CAP_SYS_PTRACE); | |
213 | else | |
214 | return has_ns_capability(current, ns, CAP_SYS_PTRACE); | |
215 | } | |
216 | ||
9f99798f TH |
217 | /* Returns 0 on success, -errno on denial. */ |
218 | static int __ptrace_may_access(struct task_struct *task, unsigned int mode) | |
ab8d11be | 219 | { |
c69e8d9c | 220 | const struct cred *cred = current_cred(), *tcred; |
caaee623 JH |
221 | int dumpable = 0; |
222 | kuid_t caller_uid; | |
223 | kgid_t caller_gid; | |
224 | ||
225 | if (!(mode & PTRACE_MODE_FSCREDS) == !(mode & PTRACE_MODE_REALCREDS)) { | |
226 | WARN(1, "denying ptrace access check without PTRACE_MODE_*CREDS\n"); | |
227 | return -EPERM; | |
228 | } | |
b6dff3ec | 229 | |
df26c40e EB |
230 | /* May we inspect the given task? |
231 | * This check is used both for attaching with ptrace | |
232 | * and for allowing access to sensitive information in /proc. | |
233 | * | |
234 | * ptrace_attach denies several cases that /proc allows | |
235 | * because setting up the necessary parent/child relationship | |
236 | * or halting the specified task is impossible. | |
237 | */ | |
caaee623 | 238 | |
df26c40e | 239 | /* Don't let security modules deny introspection */ |
73af963f | 240 | if (same_thread_group(task, current)) |
df26c40e | 241 | return 0; |
c69e8d9c | 242 | rcu_read_lock(); |
caaee623 JH |
243 | if (mode & PTRACE_MODE_FSCREDS) { |
244 | caller_uid = cred->fsuid; | |
245 | caller_gid = cred->fsgid; | |
246 | } else { | |
247 | /* | |
248 | * Using the euid would make more sense here, but something | |
249 | * in userland might rely on the old behavior, and this | |
250 | * shouldn't be a security problem since | |
251 | * PTRACE_MODE_REALCREDS implies that the caller explicitly | |
252 | * used a syscall that requests access to another process | |
253 | * (and not a filesystem syscall to procfs). | |
254 | */ | |
255 | caller_uid = cred->uid; | |
256 | caller_gid = cred->gid; | |
257 | } | |
c69e8d9c | 258 | tcred = __task_cred(task); |
caaee623 JH |
259 | if (uid_eq(caller_uid, tcred->euid) && |
260 | uid_eq(caller_uid, tcred->suid) && | |
261 | uid_eq(caller_uid, tcred->uid) && | |
262 | gid_eq(caller_gid, tcred->egid) && | |
263 | gid_eq(caller_gid, tcred->sgid) && | |
264 | gid_eq(caller_gid, tcred->gid)) | |
8409cca7 | 265 | goto ok; |
c4a4d603 | 266 | if (ptrace_has_cap(tcred->user_ns, mode)) |
8409cca7 SH |
267 | goto ok; |
268 | rcu_read_unlock(); | |
269 | return -EPERM; | |
270 | ok: | |
c69e8d9c | 271 | rcu_read_unlock(); |
ab8d11be | 272 | smp_rmb(); |
df26c40e | 273 | if (task->mm) |
6c5d5238 | 274 | dumpable = get_dumpable(task->mm); |
4c44aaaf | 275 | rcu_read_lock(); |
d049f74f KC |
276 | if (dumpable != SUID_DUMP_USER && |
277 | !ptrace_has_cap(__task_cred(task)->user_ns, mode)) { | |
4c44aaaf | 278 | rcu_read_unlock(); |
ab8d11be | 279 | return -EPERM; |
4c44aaaf EB |
280 | } |
281 | rcu_read_unlock(); | |
ab8d11be | 282 | |
9e48858f | 283 | return security_ptrace_access_check(task, mode); |
ab8d11be MS |
284 | } |
285 | ||
006ebb40 | 286 | bool ptrace_may_access(struct task_struct *task, unsigned int mode) |
ab8d11be MS |
287 | { |
288 | int err; | |
289 | task_lock(task); | |
006ebb40 | 290 | err = __ptrace_may_access(task, mode); |
ab8d11be | 291 | task_unlock(task); |
3a709703 | 292 | return !err; |
ab8d11be MS |
293 | } |
294 | ||
3544d72a | 295 | static int ptrace_attach(struct task_struct *task, long request, |
aa9147c9 | 296 | unsigned long addr, |
3544d72a | 297 | unsigned long flags) |
1da177e4 | 298 | { |
3544d72a | 299 | bool seize = (request == PTRACE_SEIZE); |
1da177e4 | 300 | int retval; |
f5b40e36 | 301 | |
3544d72a | 302 | retval = -EIO; |
aa9147c9 DV |
303 | if (seize) { |
304 | if (addr != 0) | |
305 | goto out; | |
aa9147c9 DV |
306 | if (flags & ~(unsigned long)PTRACE_O_MASK) |
307 | goto out; | |
308 | flags = PT_PTRACED | PT_SEIZED | (flags << PT_OPT_FLAG_SHIFT); | |
309 | } else { | |
310 | flags = PT_PTRACED; | |
311 | } | |
3544d72a | 312 | |
a5cb013d AV |
313 | audit_ptrace(task); |
314 | ||
1da177e4 | 315 | retval = -EPERM; |
b79b7ba9 ON |
316 | if (unlikely(task->flags & PF_KTHREAD)) |
317 | goto out; | |
bac0abd6 | 318 | if (same_thread_group(task, current)) |
f5b40e36 LT |
319 | goto out; |
320 | ||
f2f0b00a ON |
321 | /* |
322 | * Protect exec's credential calculations against our interference; | |
86b6c1f3 | 323 | * SUID, SGID and LSM creds get determined differently |
5e751e99 | 324 | * under ptrace. |
d84f4f99 | 325 | */ |
793285fc | 326 | retval = -ERESTARTNOINTR; |
9b1bf12d | 327 | if (mutex_lock_interruptible(&task->signal->cred_guard_mutex)) |
d84f4f99 | 328 | goto out; |
f5b40e36 | 329 | |
4b105cbb | 330 | task_lock(task); |
caaee623 | 331 | retval = __ptrace_may_access(task, PTRACE_MODE_ATTACH_REALCREDS); |
4b105cbb | 332 | task_unlock(task); |
1da177e4 | 333 | if (retval) |
4b105cbb | 334 | goto unlock_creds; |
1da177e4 | 335 | |
4b105cbb | 336 | write_lock_irq(&tasklist_lock); |
b79b7ba9 ON |
337 | retval = -EPERM; |
338 | if (unlikely(task->exit_state)) | |
4b105cbb | 339 | goto unlock_tasklist; |
f2f0b00a | 340 | if (task->ptrace) |
4b105cbb | 341 | goto unlock_tasklist; |
b79b7ba9 | 342 | |
3544d72a | 343 | if (seize) |
aa9147c9 | 344 | flags |= PT_SEIZED; |
4c44aaaf EB |
345 | rcu_read_lock(); |
346 | if (ns_capable(__task_cred(task)->user_ns, CAP_SYS_PTRACE)) | |
aa9147c9 | 347 | flags |= PT_PTRACE_CAP; |
4c44aaaf | 348 | rcu_read_unlock(); |
aa9147c9 | 349 | task->ptrace = flags; |
1da177e4 | 350 | |
1da177e4 | 351 | __ptrace_link(task, current); |
3544d72a TH |
352 | |
353 | /* SEIZE doesn't trap tracee on attach */ | |
354 | if (!seize) | |
355 | send_sig_info(SIGSTOP, SEND_SIG_FORCED, task); | |
b79b7ba9 | 356 | |
d79fdd6d TH |
357 | spin_lock(&task->sighand->siglock); |
358 | ||
359 | /* | |
73ddff2b | 360 | * If the task is already STOPPED, set JOBCTL_TRAP_STOP and |
d79fdd6d TH |
361 | * TRAPPING, and kick it so that it transits to TRACED. TRAPPING |
362 | * will be cleared if the child completes the transition or any | |
363 | * event which clears the group stop states happens. We'll wait | |
364 | * for the transition to complete before returning from this | |
365 | * function. | |
366 | * | |
367 | * This hides STOPPED -> RUNNING -> TRACED transition from the | |
368 | * attaching thread but a different thread in the same group can | |
369 | * still observe the transient RUNNING state. IOW, if another | |
370 | * thread's WNOHANG wait(2) on the stopped tracee races against | |
371 | * ATTACH, the wait(2) may fail due to the transient RUNNING. | |
372 | * | |
373 | * The following task_is_stopped() test is safe as both transitions | |
374 | * in and out of STOPPED are protected by siglock. | |
375 | */ | |
7dd3db54 | 376 | if (task_is_stopped(task) && |
73ddff2b | 377 | task_set_jobctl_pending(task, JOBCTL_TRAP_STOP | JOBCTL_TRAPPING)) |
910ffdb1 | 378 | signal_wake_up_state(task, __TASK_STOPPED); |
d79fdd6d TH |
379 | |
380 | spin_unlock(&task->sighand->siglock); | |
381 | ||
b79b7ba9 | 382 | retval = 0; |
4b105cbb ON |
383 | unlock_tasklist: |
384 | write_unlock_irq(&tasklist_lock); | |
385 | unlock_creds: | |
9b1bf12d | 386 | mutex_unlock(&task->signal->cred_guard_mutex); |
f5b40e36 | 387 | out: |
f701e5b7 | 388 | if (!retval) { |
7c3b00e0 ON |
389 | /* |
390 | * We do not bother to change retval or clear JOBCTL_TRAPPING | |
391 | * if wait_on_bit() was interrupted by SIGKILL. The tracer will | |
392 | * not return to user-mode, it will exit and clear this bit in | |
393 | * __ptrace_unlink() if it wasn't already cleared by the tracee; | |
394 | * and until then nobody can ptrace this task. | |
395 | */ | |
396 | wait_on_bit(&task->jobctl, JOBCTL_TRAPPING_BIT, TASK_KILLABLE); | |
f701e5b7 VZ |
397 | proc_ptrace_connector(task, PTRACE_ATTACH); |
398 | } | |
399 | ||
1da177e4 LT |
400 | return retval; |
401 | } | |
402 | ||
f2f0b00a ON |
403 | /** |
404 | * ptrace_traceme -- helper for PTRACE_TRACEME | |
405 | * | |
406 | * Performs checks and sets PT_PTRACED. | |
407 | * Should be used by all ptrace implementations for PTRACE_TRACEME. | |
408 | */ | |
e3e89cc5 | 409 | static int ptrace_traceme(void) |
f2f0b00a ON |
410 | { |
411 | int ret = -EPERM; | |
412 | ||
4b105cbb ON |
413 | write_lock_irq(&tasklist_lock); |
414 | /* Are we already being traced? */ | |
f2f0b00a | 415 | if (!current->ptrace) { |
f2f0b00a | 416 | ret = security_ptrace_traceme(current->parent); |
f2f0b00a ON |
417 | /* |
418 | * Check PF_EXITING to ensure ->real_parent has not passed | |
419 | * exit_ptrace(). Otherwise we don't report the error but | |
420 | * pretend ->real_parent untraces us right after return. | |
421 | */ | |
422 | if (!ret && !(current->real_parent->flags & PF_EXITING)) { | |
423 | current->ptrace = PT_PTRACED; | |
424 | __ptrace_link(current, current->real_parent); | |
425 | } | |
f2f0b00a | 426 | } |
4b105cbb ON |
427 | write_unlock_irq(&tasklist_lock); |
428 | ||
f2f0b00a ON |
429 | return ret; |
430 | } | |
431 | ||
39c626ae ON |
432 | /* |
433 | * Called with irqs disabled, returns true if childs should reap themselves. | |
434 | */ | |
435 | static int ignoring_children(struct sighand_struct *sigh) | |
436 | { | |
437 | int ret; | |
438 | spin_lock(&sigh->siglock); | |
439 | ret = (sigh->action[SIGCHLD-1].sa.sa_handler == SIG_IGN) || | |
440 | (sigh->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT); | |
441 | spin_unlock(&sigh->siglock); | |
442 | return ret; | |
443 | } | |
444 | ||
445 | /* | |
446 | * Called with tasklist_lock held for writing. | |
447 | * Unlink a traced task, and clean it up if it was a traced zombie. | |
448 | * Return true if it needs to be reaped with release_task(). | |
449 | * (We can't call release_task() here because we already hold tasklist_lock.) | |
450 | * | |
451 | * If it's a zombie, our attachedness prevented normal parent notification | |
452 | * or self-reaping. Do notification now if it would have happened earlier. | |
453 | * If it should reap itself, return true. | |
454 | * | |
a7f0765e ON |
455 | * If it's our own child, there is no notification to do. But if our normal |
456 | * children self-reap, then this child was prevented by ptrace and we must | |
457 | * reap it now, in that case we must also wake up sub-threads sleeping in | |
458 | * do_wait(). | |
39c626ae ON |
459 | */ |
460 | static bool __ptrace_detach(struct task_struct *tracer, struct task_struct *p) | |
461 | { | |
9843a1e9 ON |
462 | bool dead; |
463 | ||
39c626ae ON |
464 | __ptrace_unlink(p); |
465 | ||
9843a1e9 ON |
466 | if (p->exit_state != EXIT_ZOMBIE) |
467 | return false; | |
468 | ||
469 | dead = !thread_group_leader(p); | |
470 | ||
471 | if (!dead && thread_group_empty(p)) { | |
472 | if (!same_thread_group(p->real_parent, tracer)) | |
473 | dead = do_notify_parent(p, p->exit_signal); | |
474 | else if (ignoring_children(tracer->sighand)) { | |
475 | __wake_up_parent(p, tracer); | |
9843a1e9 | 476 | dead = true; |
39c626ae ON |
477 | } |
478 | } | |
9843a1e9 ON |
479 | /* Mark it as in the process of being reaped. */ |
480 | if (dead) | |
481 | p->exit_state = EXIT_DEAD; | |
482 | return dead; | |
39c626ae ON |
483 | } |
484 | ||
e3e89cc5 | 485 | static int ptrace_detach(struct task_struct *child, unsigned int data) |
1da177e4 | 486 | { |
7ed20e1a | 487 | if (!valid_signal(data)) |
5ecfbae0 | 488 | return -EIO; |
1da177e4 LT |
489 | |
490 | /* Architecture-specific hardware disable .. */ | |
491 | ptrace_disable(child); | |
7d941432 | 492 | clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); |
1da177e4 | 493 | |
95c3eb76 | 494 | write_lock_irq(&tasklist_lock); |
39c626ae | 495 | /* |
64a4096c ON |
496 | * We rely on ptrace_freeze_traced(). It can't be killed and |
497 | * untraced by another thread, it can't be a zombie. | |
39c626ae | 498 | */ |
64a4096c ON |
499 | WARN_ON(!child->ptrace || child->exit_state); |
500 | /* | |
501 | * tasklist_lock avoids the race with wait_task_stopped(), see | |
502 | * the comment in ptrace_resume(). | |
503 | */ | |
504 | child->exit_code = data; | |
505 | __ptrace_detach(current, child); | |
1da177e4 LT |
506 | write_unlock_irq(&tasklist_lock); |
507 | ||
f701e5b7 | 508 | proc_ptrace_connector(child, PTRACE_DETACH); |
4576145c | 509 | |
1da177e4 LT |
510 | return 0; |
511 | } | |
512 | ||
39c626ae | 513 | /* |
c7e49c14 | 514 | * Detach all tasks we were using ptrace on. Called with tasklist held |
7c8bd232 | 515 | * for writing. |
39c626ae | 516 | */ |
7c8bd232 | 517 | void exit_ptrace(struct task_struct *tracer, struct list_head *dead) |
39c626ae ON |
518 | { |
519 | struct task_struct *p, *n; | |
c7e49c14 | 520 | |
39c626ae | 521 | list_for_each_entry_safe(p, n, &tracer->ptraced, ptrace_entry) { |
992fb6e1 ON |
522 | if (unlikely(p->ptrace & PT_EXITKILL)) |
523 | send_sig_info(SIGKILL, SEND_SIG_FORCED, p); | |
524 | ||
39c626ae | 525 | if (__ptrace_detach(tracer, p)) |
7c8bd232 | 526 | list_add(&p->ptrace_entry, dead); |
39c626ae ON |
527 | } |
528 | } | |
529 | ||
1da177e4 LT |
530 | int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len) |
531 | { | |
532 | int copied = 0; | |
533 | ||
534 | while (len > 0) { | |
535 | char buf[128]; | |
536 | int this_len, retval; | |
537 | ||
538 | this_len = (len > sizeof(buf)) ? sizeof(buf) : len; | |
539 | retval = access_process_vm(tsk, src, buf, this_len, 0); | |
540 | if (!retval) { | |
541 | if (copied) | |
542 | break; | |
543 | return -EIO; | |
544 | } | |
545 | if (copy_to_user(dst, buf, retval)) | |
546 | return -EFAULT; | |
547 | copied += retval; | |
548 | src += retval; | |
549 | dst += retval; | |
3a709703 | 550 | len -= retval; |
1da177e4 LT |
551 | } |
552 | return copied; | |
553 | } | |
554 | ||
555 | int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len) | |
556 | { | |
557 | int copied = 0; | |
558 | ||
559 | while (len > 0) { | |
560 | char buf[128]; | |
561 | int this_len, retval; | |
562 | ||
563 | this_len = (len > sizeof(buf)) ? sizeof(buf) : len; | |
564 | if (copy_from_user(buf, src, this_len)) | |
565 | return -EFAULT; | |
566 | retval = access_process_vm(tsk, dst, buf, this_len, 1); | |
567 | if (!retval) { | |
568 | if (copied) | |
569 | break; | |
570 | return -EIO; | |
571 | } | |
572 | copied += retval; | |
573 | src += retval; | |
574 | dst += retval; | |
3a709703 | 575 | len -= retval; |
1da177e4 LT |
576 | } |
577 | return copied; | |
578 | } | |
579 | ||
4abf9869 | 580 | static int ptrace_setoptions(struct task_struct *child, unsigned long data) |
1da177e4 | 581 | { |
86b6c1f3 DV |
582 | unsigned flags; |
583 | ||
8c5cf9e5 DV |
584 | if (data & ~(unsigned long)PTRACE_O_MASK) |
585 | return -EINVAL; | |
586 | ||
13c4a901 | 587 | if (unlikely(data & PTRACE_O_SUSPEND_SECCOMP)) { |
97f2645f MY |
588 | if (!IS_ENABLED(CONFIG_CHECKPOINT_RESTORE) || |
589 | !IS_ENABLED(CONFIG_SECCOMP)) | |
13c4a901 TA |
590 | return -EINVAL; |
591 | ||
592 | if (!capable(CAP_SYS_ADMIN)) | |
593 | return -EPERM; | |
594 | ||
595 | if (seccomp_mode(¤t->seccomp) != SECCOMP_MODE_DISABLED || | |
596 | current->ptrace & PT_SUSPEND_SECCOMP) | |
597 | return -EPERM; | |
598 | } | |
599 | ||
86b6c1f3 DV |
600 | /* Avoid intermediate state when all opts are cleared */ |
601 | flags = child->ptrace; | |
602 | flags &= ~(PTRACE_O_MASK << PT_OPT_FLAG_SHIFT); | |
603 | flags |= (data << PT_OPT_FLAG_SHIFT); | |
604 | child->ptrace = flags; | |
1da177e4 | 605 | |
8c5cf9e5 | 606 | return 0; |
1da177e4 LT |
607 | } |
608 | ||
e16b2781 | 609 | static int ptrace_getsiginfo(struct task_struct *child, siginfo_t *info) |
1da177e4 | 610 | { |
e4961254 | 611 | unsigned long flags; |
1da177e4 LT |
612 | int error = -ESRCH; |
613 | ||
e4961254 | 614 | if (lock_task_sighand(child, &flags)) { |
1da177e4 | 615 | error = -EINVAL; |
1da177e4 | 616 | if (likely(child->last_siginfo != NULL)) { |
e16b2781 | 617 | *info = *child->last_siginfo; |
1da177e4 LT |
618 | error = 0; |
619 | } | |
e4961254 | 620 | unlock_task_sighand(child, &flags); |
1da177e4 | 621 | } |
1da177e4 LT |
622 | return error; |
623 | } | |
624 | ||
e16b2781 | 625 | static int ptrace_setsiginfo(struct task_struct *child, const siginfo_t *info) |
1da177e4 | 626 | { |
e4961254 | 627 | unsigned long flags; |
1da177e4 LT |
628 | int error = -ESRCH; |
629 | ||
e4961254 | 630 | if (lock_task_sighand(child, &flags)) { |
1da177e4 | 631 | error = -EINVAL; |
1da177e4 | 632 | if (likely(child->last_siginfo != NULL)) { |
e16b2781 | 633 | *child->last_siginfo = *info; |
1da177e4 LT |
634 | error = 0; |
635 | } | |
e4961254 | 636 | unlock_task_sighand(child, &flags); |
1da177e4 | 637 | } |
1da177e4 LT |
638 | return error; |
639 | } | |
640 | ||
84c751bd AV |
641 | static int ptrace_peek_siginfo(struct task_struct *child, |
642 | unsigned long addr, | |
643 | unsigned long data) | |
644 | { | |
645 | struct ptrace_peeksiginfo_args arg; | |
646 | struct sigpending *pending; | |
647 | struct sigqueue *q; | |
648 | int ret, i; | |
649 | ||
650 | ret = copy_from_user(&arg, (void __user *) addr, | |
651 | sizeof(struct ptrace_peeksiginfo_args)); | |
652 | if (ret) | |
653 | return -EFAULT; | |
654 | ||
655 | if (arg.flags & ~PTRACE_PEEKSIGINFO_SHARED) | |
656 | return -EINVAL; /* unknown flags */ | |
657 | ||
658 | if (arg.nr < 0) | |
659 | return -EINVAL; | |
660 | ||
661 | if (arg.flags & PTRACE_PEEKSIGINFO_SHARED) | |
662 | pending = &child->signal->shared_pending; | |
663 | else | |
664 | pending = &child->pending; | |
665 | ||
666 | for (i = 0; i < arg.nr; ) { | |
667 | siginfo_t info; | |
668 | s32 off = arg.off + i; | |
669 | ||
670 | spin_lock_irq(&child->sighand->siglock); | |
671 | list_for_each_entry(q, &pending->list, list) { | |
672 | if (!off--) { | |
673 | copy_siginfo(&info, &q->info); | |
674 | break; | |
675 | } | |
676 | } | |
677 | spin_unlock_irq(&child->sighand->siglock); | |
678 | ||
679 | if (off >= 0) /* beyond the end of the list */ | |
680 | break; | |
681 | ||
682 | #ifdef CONFIG_COMPAT | |
5c465217 | 683 | if (unlikely(in_compat_syscall())) { |
84c751bd AV |
684 | compat_siginfo_t __user *uinfo = compat_ptr(data); |
685 | ||
706b23bd MD |
686 | if (copy_siginfo_to_user32(uinfo, &info) || |
687 | __put_user(info.si_code, &uinfo->si_code)) { | |
688 | ret = -EFAULT; | |
689 | break; | |
690 | } | |
691 | ||
84c751bd AV |
692 | } else |
693 | #endif | |
694 | { | |
695 | siginfo_t __user *uinfo = (siginfo_t __user *) data; | |
696 | ||
706b23bd MD |
697 | if (copy_siginfo_to_user(uinfo, &info) || |
698 | __put_user(info.si_code, &uinfo->si_code)) { | |
699 | ret = -EFAULT; | |
700 | break; | |
701 | } | |
84c751bd AV |
702 | } |
703 | ||
704 | data += sizeof(siginfo_t); | |
705 | i++; | |
706 | ||
707 | if (signal_pending(current)) | |
708 | break; | |
709 | ||
710 | cond_resched(); | |
711 | } | |
712 | ||
713 | if (i > 0) | |
714 | return i; | |
715 | ||
716 | return ret; | |
717 | } | |
36df29d7 RM |
718 | |
719 | #ifdef PTRACE_SINGLESTEP | |
720 | #define is_singlestep(request) ((request) == PTRACE_SINGLESTEP) | |
721 | #else | |
722 | #define is_singlestep(request) 0 | |
723 | #endif | |
724 | ||
5b88abbf RM |
725 | #ifdef PTRACE_SINGLEBLOCK |
726 | #define is_singleblock(request) ((request) == PTRACE_SINGLEBLOCK) | |
727 | #else | |
728 | #define is_singleblock(request) 0 | |
729 | #endif | |
730 | ||
36df29d7 RM |
731 | #ifdef PTRACE_SYSEMU |
732 | #define is_sysemu_singlestep(request) ((request) == PTRACE_SYSEMU_SINGLESTEP) | |
733 | #else | |
734 | #define is_sysemu_singlestep(request) 0 | |
735 | #endif | |
736 | ||
4abf9869 NK |
737 | static int ptrace_resume(struct task_struct *child, long request, |
738 | unsigned long data) | |
36df29d7 | 739 | { |
b72c1869 ON |
740 | bool need_siglock; |
741 | ||
36df29d7 RM |
742 | if (!valid_signal(data)) |
743 | return -EIO; | |
744 | ||
745 | if (request == PTRACE_SYSCALL) | |
746 | set_tsk_thread_flag(child, TIF_SYSCALL_TRACE); | |
747 | else | |
748 | clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); | |
749 | ||
750 | #ifdef TIF_SYSCALL_EMU | |
751 | if (request == PTRACE_SYSEMU || request == PTRACE_SYSEMU_SINGLESTEP) | |
752 | set_tsk_thread_flag(child, TIF_SYSCALL_EMU); | |
753 | else | |
754 | clear_tsk_thread_flag(child, TIF_SYSCALL_EMU); | |
755 | #endif | |
756 | ||
5b88abbf RM |
757 | if (is_singleblock(request)) { |
758 | if (unlikely(!arch_has_block_step())) | |
759 | return -EIO; | |
760 | user_enable_block_step(child); | |
761 | } else if (is_singlestep(request) || is_sysemu_singlestep(request)) { | |
36df29d7 RM |
762 | if (unlikely(!arch_has_single_step())) |
763 | return -EIO; | |
764 | user_enable_single_step(child); | |
3a709703 | 765 | } else { |
36df29d7 | 766 | user_disable_single_step(child); |
3a709703 | 767 | } |
36df29d7 | 768 | |
b72c1869 ON |
769 | /* |
770 | * Change ->exit_code and ->state under siglock to avoid the race | |
771 | * with wait_task_stopped() in between; a non-zero ->exit_code will | |
772 | * wrongly look like another report from tracee. | |
773 | * | |
774 | * Note that we need siglock even if ->exit_code == data and/or this | |
775 | * status was not reported yet, the new status must not be cleared by | |
776 | * wait_task_stopped() after resume. | |
777 | * | |
778 | * If data == 0 we do not care if wait_task_stopped() reports the old | |
779 | * status and clears the code too; this can't race with the tracee, it | |
780 | * takes siglock after resume. | |
781 | */ | |
782 | need_siglock = data && !thread_group_empty(current); | |
783 | if (need_siglock) | |
784 | spin_lock_irq(&child->sighand->siglock); | |
36df29d7 | 785 | child->exit_code = data; |
0666fb51 | 786 | wake_up_state(child, __TASK_TRACED); |
b72c1869 ON |
787 | if (need_siglock) |
788 | spin_unlock_irq(&child->sighand->siglock); | |
36df29d7 RM |
789 | |
790 | return 0; | |
791 | } | |
792 | ||
2225a122 SS |
793 | #ifdef CONFIG_HAVE_ARCH_TRACEHOOK |
794 | ||
795 | static const struct user_regset * | |
796 | find_regset(const struct user_regset_view *view, unsigned int type) | |
797 | { | |
798 | const struct user_regset *regset; | |
799 | int n; | |
800 | ||
801 | for (n = 0; n < view->n; ++n) { | |
802 | regset = view->regsets + n; | |
803 | if (regset->core_note_type == type) | |
804 | return regset; | |
805 | } | |
806 | ||
807 | return NULL; | |
808 | } | |
809 | ||
810 | static int ptrace_regset(struct task_struct *task, int req, unsigned int type, | |
811 | struct iovec *kiov) | |
812 | { | |
813 | const struct user_regset_view *view = task_user_regset_view(task); | |
814 | const struct user_regset *regset = find_regset(view, type); | |
815 | int regset_no; | |
816 | ||
817 | if (!regset || (kiov->iov_len % regset->size) != 0) | |
c6a0dd7e | 818 | return -EINVAL; |
2225a122 SS |
819 | |
820 | regset_no = regset - view->regsets; | |
821 | kiov->iov_len = min(kiov->iov_len, | |
822 | (__kernel_size_t) (regset->n * regset->size)); | |
823 | ||
824 | if (req == PTRACE_GETREGSET) | |
825 | return copy_regset_to_user(task, view, regset_no, 0, | |
826 | kiov->iov_len, kiov->iov_base); | |
827 | else | |
828 | return copy_regset_from_user(task, view, regset_no, 0, | |
829 | kiov->iov_len, kiov->iov_base); | |
830 | } | |
831 | ||
e8440c14 JS |
832 | /* |
833 | * This is declared in linux/regset.h and defined in machine-dependent | |
834 | * code. We put the export here, near the primary machine-neutral use, | |
835 | * to ensure no machine forgets it. | |
836 | */ | |
837 | EXPORT_SYMBOL_GPL(task_user_regset_view); | |
2225a122 SS |
838 | #endif |
839 | ||
1da177e4 | 840 | int ptrace_request(struct task_struct *child, long request, |
4abf9869 | 841 | unsigned long addr, unsigned long data) |
1da177e4 | 842 | { |
fca26f26 | 843 | bool seized = child->ptrace & PT_SEIZED; |
1da177e4 | 844 | int ret = -EIO; |
544b2c91 | 845 | siginfo_t siginfo, *si; |
9fed81dc NK |
846 | void __user *datavp = (void __user *) data; |
847 | unsigned long __user *datalp = datavp; | |
fca26f26 | 848 | unsigned long flags; |
1da177e4 LT |
849 | |
850 | switch (request) { | |
16c3e389 RM |
851 | case PTRACE_PEEKTEXT: |
852 | case PTRACE_PEEKDATA: | |
853 | return generic_ptrace_peekdata(child, addr, data); | |
854 | case PTRACE_POKETEXT: | |
855 | case PTRACE_POKEDATA: | |
856 | return generic_ptrace_pokedata(child, addr, data); | |
857 | ||
1da177e4 LT |
858 | #ifdef PTRACE_OLDSETOPTIONS |
859 | case PTRACE_OLDSETOPTIONS: | |
860 | #endif | |
861 | case PTRACE_SETOPTIONS: | |
862 | ret = ptrace_setoptions(child, data); | |
863 | break; | |
864 | case PTRACE_GETEVENTMSG: | |
9fed81dc | 865 | ret = put_user(child->ptrace_message, datalp); |
1da177e4 | 866 | break; |
e16b2781 | 867 | |
84c751bd AV |
868 | case PTRACE_PEEKSIGINFO: |
869 | ret = ptrace_peek_siginfo(child, addr, data); | |
870 | break; | |
871 | ||
1da177e4 | 872 | case PTRACE_GETSIGINFO: |
e16b2781 RM |
873 | ret = ptrace_getsiginfo(child, &siginfo); |
874 | if (!ret) | |
9fed81dc | 875 | ret = copy_siginfo_to_user(datavp, &siginfo); |
1da177e4 | 876 | break; |
e16b2781 | 877 | |
1da177e4 | 878 | case PTRACE_SETSIGINFO: |
9fed81dc | 879 | if (copy_from_user(&siginfo, datavp, sizeof siginfo)) |
e16b2781 RM |
880 | ret = -EFAULT; |
881 | else | |
882 | ret = ptrace_setsiginfo(child, &siginfo); | |
1da177e4 | 883 | break; |
e16b2781 | 884 | |
29000cae AV |
885 | case PTRACE_GETSIGMASK: |
886 | if (addr != sizeof(sigset_t)) { | |
887 | ret = -EINVAL; | |
888 | break; | |
889 | } | |
890 | ||
891 | if (copy_to_user(datavp, &child->blocked, sizeof(sigset_t))) | |
892 | ret = -EFAULT; | |
893 | else | |
894 | ret = 0; | |
895 | ||
896 | break; | |
897 | ||
898 | case PTRACE_SETSIGMASK: { | |
899 | sigset_t new_set; | |
900 | ||
901 | if (addr != sizeof(sigset_t)) { | |
902 | ret = -EINVAL; | |
903 | break; | |
904 | } | |
905 | ||
906 | if (copy_from_user(&new_set, datavp, sizeof(sigset_t))) { | |
907 | ret = -EFAULT; | |
908 | break; | |
909 | } | |
910 | ||
911 | sigdelsetmask(&new_set, sigmask(SIGKILL)|sigmask(SIGSTOP)); | |
912 | ||
913 | /* | |
914 | * Every thread does recalc_sigpending() after resume, so | |
915 | * retarget_shared_pending() and recalc_sigpending() are not | |
916 | * called here. | |
917 | */ | |
918 | spin_lock_irq(&child->sighand->siglock); | |
919 | child->blocked = new_set; | |
920 | spin_unlock_irq(&child->sighand->siglock); | |
921 | ||
922 | ret = 0; | |
923 | break; | |
924 | } | |
925 | ||
fca26f26 TH |
926 | case PTRACE_INTERRUPT: |
927 | /* | |
928 | * Stop tracee without any side-effect on signal or job | |
929 | * control. At least one trap is guaranteed to happen | |
930 | * after this request. If @child is already trapped, the | |
931 | * current trap is not disturbed and another trap will | |
932 | * happen after the current trap is ended with PTRACE_CONT. | |
933 | * | |
934 | * The actual trap might not be PTRACE_EVENT_STOP trap but | |
935 | * the pending condition is cleared regardless. | |
936 | */ | |
937 | if (unlikely(!seized || !lock_task_sighand(child, &flags))) | |
938 | break; | |
939 | ||
544b2c91 TH |
940 | /* |
941 | * INTERRUPT doesn't disturb existing trap sans one | |
942 | * exception. If ptracer issued LISTEN for the current | |
943 | * STOP, this INTERRUPT should clear LISTEN and re-trap | |
944 | * tracee into STOP. | |
945 | */ | |
fca26f26 | 946 | if (likely(task_set_jobctl_pending(child, JOBCTL_TRAP_STOP))) |
910ffdb1 | 947 | ptrace_signal_wake_up(child, child->jobctl & JOBCTL_LISTENING); |
544b2c91 TH |
948 | |
949 | unlock_task_sighand(child, &flags); | |
950 | ret = 0; | |
951 | break; | |
952 | ||
953 | case PTRACE_LISTEN: | |
954 | /* | |
955 | * Listen for events. Tracee must be in STOP. It's not | |
956 | * resumed per-se but is not considered to be in TRACED by | |
957 | * wait(2) or ptrace(2). If an async event (e.g. group | |
958 | * stop state change) happens, tracee will enter STOP trap | |
959 | * again. Alternatively, ptracer can issue INTERRUPT to | |
960 | * finish listening and re-trap tracee into STOP. | |
961 | */ | |
962 | if (unlikely(!seized || !lock_task_sighand(child, &flags))) | |
963 | break; | |
964 | ||
965 | si = child->last_siginfo; | |
f9d81f61 ON |
966 | if (likely(si && (si->si_code >> 8) == PTRACE_EVENT_STOP)) { |
967 | child->jobctl |= JOBCTL_LISTENING; | |
968 | /* | |
969 | * If NOTIFY is set, it means event happened between | |
970 | * start of this trap and now. Trigger re-trap. | |
971 | */ | |
972 | if (child->jobctl & JOBCTL_TRAP_NOTIFY) | |
910ffdb1 | 973 | ptrace_signal_wake_up(child, true); |
f9d81f61 ON |
974 | ret = 0; |
975 | } | |
fca26f26 | 976 | unlock_task_sighand(child, &flags); |
fca26f26 TH |
977 | break; |
978 | ||
1bcf5482 AD |
979 | case PTRACE_DETACH: /* detach a process that was attached. */ |
980 | ret = ptrace_detach(child, data); | |
981 | break; | |
36df29d7 | 982 | |
9c1a1259 MF |
983 | #ifdef CONFIG_BINFMT_ELF_FDPIC |
984 | case PTRACE_GETFDPIC: { | |
e0129ef9 | 985 | struct mm_struct *mm = get_task_mm(child); |
9c1a1259 MF |
986 | unsigned long tmp = 0; |
987 | ||
e0129ef9 ON |
988 | ret = -ESRCH; |
989 | if (!mm) | |
990 | break; | |
991 | ||
9c1a1259 MF |
992 | switch (addr) { |
993 | case PTRACE_GETFDPIC_EXEC: | |
e0129ef9 | 994 | tmp = mm->context.exec_fdpic_loadmap; |
9c1a1259 MF |
995 | break; |
996 | case PTRACE_GETFDPIC_INTERP: | |
e0129ef9 | 997 | tmp = mm->context.interp_fdpic_loadmap; |
9c1a1259 MF |
998 | break; |
999 | default: | |
1000 | break; | |
1001 | } | |
e0129ef9 | 1002 | mmput(mm); |
9c1a1259 | 1003 | |
9fed81dc | 1004 | ret = put_user(tmp, datalp); |
9c1a1259 MF |
1005 | break; |
1006 | } | |
1007 | #endif | |
1008 | ||
36df29d7 RM |
1009 | #ifdef PTRACE_SINGLESTEP |
1010 | case PTRACE_SINGLESTEP: | |
1011 | #endif | |
5b88abbf RM |
1012 | #ifdef PTRACE_SINGLEBLOCK |
1013 | case PTRACE_SINGLEBLOCK: | |
1014 | #endif | |
36df29d7 RM |
1015 | #ifdef PTRACE_SYSEMU |
1016 | case PTRACE_SYSEMU: | |
1017 | case PTRACE_SYSEMU_SINGLESTEP: | |
1018 | #endif | |
1019 | case PTRACE_SYSCALL: | |
1020 | case PTRACE_CONT: | |
1021 | return ptrace_resume(child, request, data); | |
1022 | ||
1023 | case PTRACE_KILL: | |
1024 | if (child->exit_state) /* already dead */ | |
1025 | return 0; | |
1026 | return ptrace_resume(child, request, SIGKILL); | |
1027 | ||
2225a122 SS |
1028 | #ifdef CONFIG_HAVE_ARCH_TRACEHOOK |
1029 | case PTRACE_GETREGSET: | |
29000cae | 1030 | case PTRACE_SETREGSET: { |
2225a122 | 1031 | struct iovec kiov; |
9fed81dc | 1032 | struct iovec __user *uiov = datavp; |
2225a122 SS |
1033 | |
1034 | if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov))) | |
1035 | return -EFAULT; | |
1036 | ||
1037 | if (__get_user(kiov.iov_base, &uiov->iov_base) || | |
1038 | __get_user(kiov.iov_len, &uiov->iov_len)) | |
1039 | return -EFAULT; | |
1040 | ||
1041 | ret = ptrace_regset(child, request, addr, &kiov); | |
1042 | if (!ret) | |
1043 | ret = __put_user(kiov.iov_len, &uiov->iov_len); | |
1044 | break; | |
1045 | } | |
1046 | #endif | |
f8e529ed TA |
1047 | |
1048 | case PTRACE_SECCOMP_GET_FILTER: | |
1049 | ret = seccomp_get_filter(child, addr, datavp); | |
1050 | break; | |
1051 | ||
1da177e4 LT |
1052 | default: |
1053 | break; | |
1054 | } | |
1055 | ||
1056 | return ret; | |
1057 | } | |
481bed45 | 1058 | |
8053bdd5 | 1059 | static struct task_struct *ptrace_get_task_struct(pid_t pid) |
6b9c7ed8 CH |
1060 | { |
1061 | struct task_struct *child; | |
481bed45 | 1062 | |
8053bdd5 | 1063 | rcu_read_lock(); |
228ebcbe | 1064 | child = find_task_by_vpid(pid); |
481bed45 CH |
1065 | if (child) |
1066 | get_task_struct(child); | |
8053bdd5 | 1067 | rcu_read_unlock(); |
f400e198 | 1068 | |
481bed45 | 1069 | if (!child) |
6b9c7ed8 CH |
1070 | return ERR_PTR(-ESRCH); |
1071 | return child; | |
481bed45 CH |
1072 | } |
1073 | ||
0ac15559 CH |
1074 | #ifndef arch_ptrace_attach |
1075 | #define arch_ptrace_attach(child) do { } while (0) | |
1076 | #endif | |
1077 | ||
4abf9869 NK |
1078 | SYSCALL_DEFINE4(ptrace, long, request, long, pid, unsigned long, addr, |
1079 | unsigned long, data) | |
481bed45 CH |
1080 | { |
1081 | struct task_struct *child; | |
1082 | long ret; | |
1083 | ||
6b9c7ed8 CH |
1084 | if (request == PTRACE_TRACEME) { |
1085 | ret = ptrace_traceme(); | |
6ea6dd93 HS |
1086 | if (!ret) |
1087 | arch_ptrace_attach(current); | |
481bed45 | 1088 | goto out; |
6b9c7ed8 CH |
1089 | } |
1090 | ||
1091 | child = ptrace_get_task_struct(pid); | |
1092 | if (IS_ERR(child)) { | |
1093 | ret = PTR_ERR(child); | |
1094 | goto out; | |
1095 | } | |
481bed45 | 1096 | |
3544d72a | 1097 | if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) { |
aa9147c9 | 1098 | ret = ptrace_attach(child, request, addr, data); |
0ac15559 CH |
1099 | /* |
1100 | * Some architectures need to do book-keeping after | |
1101 | * a ptrace attach. | |
1102 | */ | |
1103 | if (!ret) | |
1104 | arch_ptrace_attach(child); | |
005f18df | 1105 | goto out_put_task_struct; |
481bed45 CH |
1106 | } |
1107 | ||
fca26f26 TH |
1108 | ret = ptrace_check_attach(child, request == PTRACE_KILL || |
1109 | request == PTRACE_INTERRUPT); | |
481bed45 CH |
1110 | if (ret < 0) |
1111 | goto out_put_task_struct; | |
1112 | ||
1113 | ret = arch_ptrace(child, request, addr, data); | |
9899d11f ON |
1114 | if (ret || request != PTRACE_DETACH) |
1115 | ptrace_unfreeze_traced(child); | |
481bed45 CH |
1116 | |
1117 | out_put_task_struct: | |
1118 | put_task_struct(child); | |
1119 | out: | |
481bed45 CH |
1120 | return ret; |
1121 | } | |
76647323 | 1122 | |
4abf9869 NK |
1123 | int generic_ptrace_peekdata(struct task_struct *tsk, unsigned long addr, |
1124 | unsigned long data) | |
76647323 AD |
1125 | { |
1126 | unsigned long tmp; | |
1127 | int copied; | |
1128 | ||
1129 | copied = access_process_vm(tsk, addr, &tmp, sizeof(tmp), 0); | |
1130 | if (copied != sizeof(tmp)) | |
1131 | return -EIO; | |
1132 | return put_user(tmp, (unsigned long __user *)data); | |
1133 | } | |
f284ce72 | 1134 | |
4abf9869 NK |
1135 | int generic_ptrace_pokedata(struct task_struct *tsk, unsigned long addr, |
1136 | unsigned long data) | |
f284ce72 AD |
1137 | { |
1138 | int copied; | |
1139 | ||
1140 | copied = access_process_vm(tsk, addr, &data, sizeof(data), 1); | |
1141 | return (copied == sizeof(data)) ? 0 : -EIO; | |
1142 | } | |
032d82d9 | 1143 | |
96b8936a | 1144 | #if defined CONFIG_COMPAT |
032d82d9 RM |
1145 | |
1146 | int compat_ptrace_request(struct task_struct *child, compat_long_t request, | |
1147 | compat_ulong_t addr, compat_ulong_t data) | |
1148 | { | |
1149 | compat_ulong_t __user *datap = compat_ptr(data); | |
1150 | compat_ulong_t word; | |
e16b2781 | 1151 | siginfo_t siginfo; |
032d82d9 RM |
1152 | int ret; |
1153 | ||
1154 | switch (request) { | |
1155 | case PTRACE_PEEKTEXT: | |
1156 | case PTRACE_PEEKDATA: | |
1157 | ret = access_process_vm(child, addr, &word, sizeof(word), 0); | |
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: | |
1166 | ret = access_process_vm(child, addr, &data, sizeof(data), 1); | |
1167 | ret = (ret != sizeof(data) ? -EIO : 0); | |
1168 | break; | |
1169 | ||
1170 | case PTRACE_GETEVENTMSG: | |
1171 | ret = put_user((compat_ulong_t) child->ptrace_message, datap); | |
1172 | break; | |
1173 | ||
e16b2781 RM |
1174 | case PTRACE_GETSIGINFO: |
1175 | ret = ptrace_getsiginfo(child, &siginfo); | |
1176 | if (!ret) | |
1177 | ret = copy_siginfo_to_user32( | |
1178 | (struct compat_siginfo __user *) datap, | |
1179 | &siginfo); | |
1180 | break; | |
1181 | ||
1182 | case PTRACE_SETSIGINFO: | |
1183 | memset(&siginfo, 0, sizeof siginfo); | |
1184 | if (copy_siginfo_from_user32( | |
1185 | &siginfo, (struct compat_siginfo __user *) datap)) | |
1186 | ret = -EFAULT; | |
1187 | else | |
1188 | ret = ptrace_setsiginfo(child, &siginfo); | |
1189 | break; | |
2225a122 SS |
1190 | #ifdef CONFIG_HAVE_ARCH_TRACEHOOK |
1191 | case PTRACE_GETREGSET: | |
1192 | case PTRACE_SETREGSET: | |
1193 | { | |
1194 | struct iovec kiov; | |
1195 | struct compat_iovec __user *uiov = | |
1196 | (struct compat_iovec __user *) datap; | |
1197 | compat_uptr_t ptr; | |
1198 | compat_size_t len; | |
1199 | ||
1200 | if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov))) | |
1201 | return -EFAULT; | |
1202 | ||
1203 | if (__get_user(ptr, &uiov->iov_base) || | |
1204 | __get_user(len, &uiov->iov_len)) | |
1205 | return -EFAULT; | |
1206 | ||
1207 | kiov.iov_base = compat_ptr(ptr); | |
1208 | kiov.iov_len = len; | |
1209 | ||
1210 | ret = ptrace_regset(child, request, addr, &kiov); | |
1211 | if (!ret) | |
1212 | ret = __put_user(kiov.iov_len, &uiov->iov_len); | |
1213 | break; | |
1214 | } | |
1215 | #endif | |
e16b2781 | 1216 | |
032d82d9 RM |
1217 | default: |
1218 | ret = ptrace_request(child, request, addr, data); | |
1219 | } | |
1220 | ||
1221 | return ret; | |
1222 | } | |
c269f196 | 1223 | |
62a6fa97 HC |
1224 | COMPAT_SYSCALL_DEFINE4(ptrace, compat_long_t, request, compat_long_t, pid, |
1225 | compat_long_t, addr, compat_long_t, data) | |
c269f196 RM |
1226 | { |
1227 | struct task_struct *child; | |
1228 | long ret; | |
1229 | ||
c269f196 RM |
1230 | if (request == PTRACE_TRACEME) { |
1231 | ret = ptrace_traceme(); | |
1232 | goto out; | |
1233 | } | |
1234 | ||
1235 | child = ptrace_get_task_struct(pid); | |
1236 | if (IS_ERR(child)) { | |
1237 | ret = PTR_ERR(child); | |
1238 | goto out; | |
1239 | } | |
1240 | ||
3544d72a | 1241 | if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) { |
aa9147c9 | 1242 | ret = ptrace_attach(child, request, addr, data); |
c269f196 RM |
1243 | /* |
1244 | * Some architectures need to do book-keeping after | |
1245 | * a ptrace attach. | |
1246 | */ | |
1247 | if (!ret) | |
1248 | arch_ptrace_attach(child); | |
1249 | goto out_put_task_struct; | |
1250 | } | |
1251 | ||
fca26f26 TH |
1252 | ret = ptrace_check_attach(child, request == PTRACE_KILL || |
1253 | request == PTRACE_INTERRUPT); | |
9899d11f | 1254 | if (!ret) { |
c269f196 | 1255 | ret = compat_arch_ptrace(child, request, addr, data); |
9899d11f ON |
1256 | if (ret || request != PTRACE_DETACH) |
1257 | ptrace_unfreeze_traced(child); | |
1258 | } | |
c269f196 RM |
1259 | |
1260 | out_put_task_struct: | |
1261 | put_task_struct(child); | |
1262 | out: | |
c269f196 RM |
1263 | return ret; |
1264 | } | |
96b8936a | 1265 | #endif /* CONFIG_COMPAT */ |