Commit | Line | Data |
---|---|---|
457c8996 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
1da177e4 LT |
2 | /* |
3 | * linux/kernel/ptrace.c | |
4 | * | |
5 | * (C) Copyright 1999 Linus Torvalds | |
6 | * | |
7 | * Common interfaces for "ptrace()" which we do not want | |
8 | * to continually duplicate across every architecture. | |
9 | */ | |
10 | ||
c59ede7b | 11 | #include <linux/capability.h> |
9984de1a | 12 | #include <linux/export.h> |
1da177e4 | 13 | #include <linux/sched.h> |
6e84f315 | 14 | #include <linux/sched/mm.h> |
f7ccbae4 | 15 | #include <linux/sched/coredump.h> |
29930025 | 16 | #include <linux/sched/task.h> |
1da177e4 LT |
17 | #include <linux/errno.h> |
18 | #include <linux/mm.h> | |
19 | #include <linux/highmem.h> | |
20 | #include <linux/pagemap.h> | |
1da177e4 LT |
21 | #include <linux/ptrace.h> |
22 | #include <linux/security.h> | |
7ed20e1a | 23 | #include <linux/signal.h> |
a27bb332 | 24 | #include <linux/uio.h> |
a5cb013d | 25 | #include <linux/audit.h> |
b488893a | 26 | #include <linux/pid_namespace.h> |
f17d30a8 | 27 | #include <linux/syscalls.h> |
3a709703 | 28 | #include <linux/uaccess.h> |
2225a122 | 29 | #include <linux/regset.h> |
bf26c018 | 30 | #include <linux/hw_breakpoint.h> |
f701e5b7 | 31 | #include <linux/cn_proc.h> |
84c751bd | 32 | #include <linux/compat.h> |
fcfc2aa0 | 33 | #include <linux/sched/signal.h> |
90f093fa | 34 | #include <linux/minmax.h> |
1da177e4 | 35 | |
201766a2 EK |
36 | #include <asm/syscall.h> /* for syscall_get_* */ |
37 | ||
84d77d3f EB |
38 | /* |
39 | * Access another process' address space via ptrace. | |
40 | * Source/target buffer must be kernel space, | |
41 | * Do not walk the page table directly, use get_user_pages | |
42 | */ | |
43 | int ptrace_access_vm(struct task_struct *tsk, unsigned long addr, | |
44 | void *buf, int len, unsigned int gup_flags) | |
45 | { | |
46 | struct mm_struct *mm; | |
47 | int ret; | |
48 | ||
49 | mm = get_task_mm(tsk); | |
50 | if (!mm) | |
51 | return 0; | |
52 | ||
53 | if (!tsk->ptrace || | |
54 | (current != tsk->parent) || | |
55 | ((get_dumpable(mm) != SUID_DUMP_USER) && | |
56 | !ptracer_capable(tsk, mm->user_ns))) { | |
57 | mmput(mm); | |
58 | return 0; | |
59 | } | |
60 | ||
d3f5ffca | 61 | ret = __access_remote_vm(mm, addr, buf, len, gup_flags); |
84d77d3f EB |
62 | mmput(mm); |
63 | ||
64 | return ret; | |
65 | } | |
66 | ||
bf53de90 | 67 | |
c70d9d80 EB |
68 | void __ptrace_link(struct task_struct *child, struct task_struct *new_parent, |
69 | const struct cred *ptracer_cred) | |
70 | { | |
71 | BUG_ON(!list_empty(&child->ptrace_entry)); | |
72 | list_add(&child->ptrace_entry, &new_parent->ptraced); | |
73 | child->parent = new_parent; | |
74 | child->ptracer_cred = get_cred(ptracer_cred); | |
75 | } | |
76 | ||
1da177e4 LT |
77 | /* |
78 | * ptrace a task: make the debugger its new parent and | |
79 | * move it to the ptrace list. | |
80 | * | |
81 | * Must be called with the tasklist lock write-held. | |
82 | */ | |
c70d9d80 | 83 | static void ptrace_link(struct task_struct *child, struct task_struct *new_parent) |
1da177e4 | 84 | { |
6994eefb | 85 | __ptrace_link(child, new_parent, current_cred()); |
1da177e4 | 86 | } |
3a709703 | 87 | |
e3bd058f TH |
88 | /** |
89 | * __ptrace_unlink - unlink ptracee and restore its execution state | |
90 | * @child: ptracee to be unlinked | |
1da177e4 | 91 | * |
0e9f0a4a TH |
92 | * Remove @child from the ptrace list, move it back to the original parent, |
93 | * and restore the execution state so that it conforms to the group stop | |
94 | * state. | |
95 | * | |
96 | * Unlinking can happen via two paths - explicit PTRACE_DETACH or ptracer | |
97 | * exiting. For PTRACE_DETACH, unless the ptracee has been killed between | |
98 | * ptrace_check_attach() and here, it's guaranteed to be in TASK_TRACED. | |
99 | * If the ptracer is exiting, the ptracee can be in any state. | |
100 | * | |
101 | * After detach, the ptracee should be in a state which conforms to the | |
102 | * group stop. If the group is stopped or in the process of stopping, the | |
103 | * ptracee should be put into TASK_STOPPED; otherwise, it should be woken | |
104 | * up from TASK_TRACED. | |
105 | * | |
106 | * If the ptracee is in TASK_TRACED and needs to be moved to TASK_STOPPED, | |
107 | * it goes through TRACED -> RUNNING -> STOPPED transition which is similar | |
108 | * to but in the opposite direction of what happens while attaching to a | |
109 | * stopped task. However, in this direction, the intermediate RUNNING | |
110 | * state is not hidden even from the current ptracer and if it immediately | |
111 | * re-attaches and performs a WNOHANG wait(2), it may fail. | |
e3bd058f TH |
112 | * |
113 | * CONTEXT: | |
114 | * write_lock_irq(tasklist_lock) | |
1da177e4 | 115 | */ |
36c8b586 | 116 | void __ptrace_unlink(struct task_struct *child) |
1da177e4 | 117 | { |
64b875f7 | 118 | const struct cred *old_cred; |
5ecfbae0 ON |
119 | BUG_ON(!child->ptrace); |
120 | ||
64c19ba2 | 121 | clear_task_syscall_work(child, SYSCALL_TRACE); |
64eb35f7 GKB |
122 | #if defined(CONFIG_GENERIC_ENTRY) || defined(TIF_SYSCALL_EMU) |
123 | clear_task_syscall_work(child, SYSCALL_EMU); | |
15532fd6 | 124 | #endif |
0a5bf409 | 125 | |
f470021a RM |
126 | child->parent = child->real_parent; |
127 | list_del_init(&child->ptrace_entry); | |
64b875f7 EB |
128 | old_cred = child->ptracer_cred; |
129 | child->ptracer_cred = NULL; | |
130 | put_cred(old_cred); | |
1da177e4 | 131 | |
1da177e4 | 132 | spin_lock(&child->sighand->siglock); |
1333ab03 | 133 | child->ptrace = 0; |
73ddff2b TH |
134 | /* |
135 | * Clear all pending traps and TRAPPING. TRAPPING should be | |
136 | * cleared regardless of JOBCTL_STOP_PENDING. Do it explicitly. | |
137 | */ | |
138 | task_clear_jobctl_pending(child, JOBCTL_TRAP_MASK); | |
139 | task_clear_jobctl_trapping(child); | |
140 | ||
0e9f0a4a | 141 | /* |
a8f072c1 | 142 | * Reinstate JOBCTL_STOP_PENDING if group stop is in effect and |
0e9f0a4a TH |
143 | * @child isn't dead. |
144 | */ | |
145 | if (!(child->flags & PF_EXITING) && | |
146 | (child->signal->flags & SIGNAL_STOP_STOPPED || | |
8a88951b | 147 | child->signal->group_stop_count)) { |
a8f072c1 | 148 | child->jobctl |= JOBCTL_STOP_PENDING; |
0e9f0a4a | 149 | |
8a88951b ON |
150 | /* |
151 | * This is only possible if this thread was cloned by the | |
152 | * traced task running in the stopped group, set the signal | |
153 | * for the future reports. | |
154 | * FIXME: we should change ptrace_init_task() to handle this | |
155 | * case. | |
156 | */ | |
157 | if (!(child->jobctl & JOBCTL_STOP_SIGMASK)) | |
158 | child->jobctl |= SIGSTOP; | |
159 | } | |
160 | ||
0e9f0a4a TH |
161 | /* |
162 | * If transition to TASK_STOPPED is pending or in TASK_TRACED, kick | |
163 | * @child in the butt. Note that @resume should be used iff @child | |
164 | * is in TASK_TRACED; otherwise, we might unduly disrupt | |
165 | * TASK_KILLABLE sleeps. | |
166 | */ | |
a8f072c1 | 167 | if (child->jobctl & JOBCTL_STOP_PENDING || task_is_traced(child)) |
910ffdb1 | 168 | ptrace_signal_wake_up(child, true); |
0e9f0a4a | 169 | |
1da177e4 | 170 | spin_unlock(&child->sighand->siglock); |
1da177e4 LT |
171 | } |
172 | ||
dbb5afad ON |
173 | static bool looks_like_a_spurious_pid(struct task_struct *task) |
174 | { | |
175 | if (task->exit_code != ((PTRACE_EVENT_EXEC << 8) | SIGTRAP)) | |
176 | return false; | |
177 | ||
178 | if (task_pid_vnr(task) == task->ptrace_message) | |
179 | return false; | |
180 | /* | |
181 | * The tracee changed its pid but the PTRACE_EVENT_EXEC event | |
182 | * was not wait()'ed, most probably debugger targets the old | |
183 | * leader which was destroyed in de_thread(). | |
184 | */ | |
185 | return true; | |
186 | } | |
187 | ||
9899d11f ON |
188 | /* Ensure that nothing can wake it up, even SIGKILL */ |
189 | static bool ptrace_freeze_traced(struct task_struct *task) | |
190 | { | |
191 | bool ret = false; | |
192 | ||
193 | /* Lockless, nobody but us can set this flag */ | |
194 | if (task->jobctl & JOBCTL_LISTENING) | |
195 | return ret; | |
196 | ||
197 | spin_lock_irq(&task->sighand->siglock); | |
dbb5afad ON |
198 | if (task_is_traced(task) && !looks_like_a_spurious_pid(task) && |
199 | !__fatal_signal_pending(task)) { | |
2f064a59 | 200 | WRITE_ONCE(task->__state, __TASK_TRACED); |
9899d11f ON |
201 | ret = true; |
202 | } | |
203 | spin_unlock_irq(&task->sighand->siglock); | |
204 | ||
205 | return ret; | |
206 | } | |
207 | ||
208 | static void ptrace_unfreeze_traced(struct task_struct *task) | |
209 | { | |
2f064a59 | 210 | if (READ_ONCE(task->__state) != __TASK_TRACED) |
9899d11f ON |
211 | return; |
212 | ||
213 | WARN_ON(!task->ptrace || task->parent != current); | |
214 | ||
5402e97a | 215 | /* |
216 | * PTRACE_LISTEN can allow ptrace_trap_notify to wake us up remotely. | |
217 | * Recheck state under the lock to close this race. | |
218 | */ | |
9899d11f | 219 | spin_lock_irq(&task->sighand->siglock); |
2f064a59 | 220 | if (READ_ONCE(task->__state) == __TASK_TRACED) { |
5402e97a | 221 | if (__fatal_signal_pending(task)) |
222 | wake_up_state(task, __TASK_TRACED); | |
223 | else | |
2f064a59 | 224 | WRITE_ONCE(task->__state, TASK_TRACED); |
5402e97a | 225 | } |
9899d11f ON |
226 | spin_unlock_irq(&task->sighand->siglock); |
227 | } | |
228 | ||
755e276b TH |
229 | /** |
230 | * ptrace_check_attach - check whether ptracee is ready for ptrace operation | |
231 | * @child: ptracee to check for | |
232 | * @ignore_state: don't check whether @child is currently %TASK_TRACED | |
233 | * | |
234 | * Check whether @child is being ptraced by %current and ready for further | |
235 | * ptrace operations. If @ignore_state is %false, @child also should be in | |
236 | * %TASK_TRACED state and on return the child is guaranteed to be traced | |
237 | * and not executing. If @ignore_state is %true, @child can be in any | |
238 | * state. | |
239 | * | |
240 | * CONTEXT: | |
241 | * Grabs and releases tasklist_lock and @child->sighand->siglock. | |
242 | * | |
243 | * RETURNS: | |
244 | * 0 on success, -ESRCH if %child is not ready. | |
1da177e4 | 245 | */ |
edea0d03 | 246 | static int ptrace_check_attach(struct task_struct *child, bool ignore_state) |
1da177e4 LT |
247 | { |
248 | int ret = -ESRCH; | |
249 | ||
250 | /* | |
251 | * We take the read lock around doing both checks to close a | |
252 | * possible race where someone else was tracing our child and | |
253 | * detached between these two checks. After this locked check, | |
254 | * we are sure that this is our traced child and that can only | |
255 | * be changed by us so it's not changing right after this. | |
256 | */ | |
257 | read_lock(&tasklist_lock); | |
9899d11f | 258 | if (child->ptrace && child->parent == current) { |
2f064a59 | 259 | WARN_ON(READ_ONCE(child->__state) == __TASK_TRACED); |
c0c0b649 ON |
260 | /* |
261 | * child->sighand can't be NULL, release_task() | |
262 | * does ptrace_unlink() before __exit_signal(). | |
263 | */ | |
9899d11f | 264 | if (ignore_state || ptrace_freeze_traced(child)) |
321fb561 | 265 | ret = 0; |
1da177e4 LT |
266 | } |
267 | read_unlock(&tasklist_lock); | |
268 | ||
9899d11f ON |
269 | if (!ret && !ignore_state) { |
270 | if (!wait_task_inactive(child, __TASK_TRACED)) { | |
271 | /* | |
272 | * This can only happen if may_ptrace_stop() fails and | |
273 | * ptrace_stop() changes ->state back to TASK_RUNNING, | |
274 | * so we should not worry about leaking __TASK_TRACED. | |
275 | */ | |
2f064a59 | 276 | WARN_ON(READ_ONCE(child->__state) == __TASK_TRACED); |
9899d11f ON |
277 | ret = -ESRCH; |
278 | } | |
279 | } | |
1da177e4 | 280 | |
1da177e4 LT |
281 | return ret; |
282 | } | |
283 | ||
cf237052 | 284 | static bool ptrace_has_cap(struct user_namespace *ns, unsigned int mode) |
69f594a3 EP |
285 | { |
286 | if (mode & PTRACE_MODE_NOAUDIT) | |
cf237052 MS |
287 | return ns_capable_noaudit(ns, CAP_SYS_PTRACE); |
288 | return ns_capable(ns, CAP_SYS_PTRACE); | |
69f594a3 EP |
289 | } |
290 | ||
9f99798f TH |
291 | /* Returns 0 on success, -errno on denial. */ |
292 | static int __ptrace_may_access(struct task_struct *task, unsigned int mode) | |
ab8d11be | 293 | { |
c69e8d9c | 294 | const struct cred *cred = current_cred(), *tcred; |
bfedb589 | 295 | struct mm_struct *mm; |
caaee623 JH |
296 | kuid_t caller_uid; |
297 | kgid_t caller_gid; | |
298 | ||
299 | if (!(mode & PTRACE_MODE_FSCREDS) == !(mode & PTRACE_MODE_REALCREDS)) { | |
300 | WARN(1, "denying ptrace access check without PTRACE_MODE_*CREDS\n"); | |
301 | return -EPERM; | |
302 | } | |
b6dff3ec | 303 | |
df26c40e EB |
304 | /* May we inspect the given task? |
305 | * This check is used both for attaching with ptrace | |
306 | * and for allowing access to sensitive information in /proc. | |
307 | * | |
308 | * ptrace_attach denies several cases that /proc allows | |
309 | * because setting up the necessary parent/child relationship | |
310 | * or halting the specified task is impossible. | |
311 | */ | |
caaee623 | 312 | |
df26c40e | 313 | /* Don't let security modules deny introspection */ |
73af963f | 314 | if (same_thread_group(task, current)) |
df26c40e | 315 | return 0; |
c69e8d9c | 316 | rcu_read_lock(); |
caaee623 JH |
317 | if (mode & PTRACE_MODE_FSCREDS) { |
318 | caller_uid = cred->fsuid; | |
319 | caller_gid = cred->fsgid; | |
320 | } else { | |
321 | /* | |
322 | * Using the euid would make more sense here, but something | |
323 | * in userland might rely on the old behavior, and this | |
324 | * shouldn't be a security problem since | |
325 | * PTRACE_MODE_REALCREDS implies that the caller explicitly | |
326 | * used a syscall that requests access to another process | |
327 | * (and not a filesystem syscall to procfs). | |
328 | */ | |
329 | caller_uid = cred->uid; | |
330 | caller_gid = cred->gid; | |
331 | } | |
c69e8d9c | 332 | tcred = __task_cred(task); |
caaee623 JH |
333 | if (uid_eq(caller_uid, tcred->euid) && |
334 | uid_eq(caller_uid, tcred->suid) && | |
335 | uid_eq(caller_uid, tcred->uid) && | |
336 | gid_eq(caller_gid, tcred->egid) && | |
337 | gid_eq(caller_gid, tcred->sgid) && | |
338 | gid_eq(caller_gid, tcred->gid)) | |
8409cca7 | 339 | goto ok; |
cf237052 | 340 | if (ptrace_has_cap(tcred->user_ns, mode)) |
8409cca7 SH |
341 | goto ok; |
342 | rcu_read_unlock(); | |
343 | return -EPERM; | |
344 | ok: | |
c69e8d9c | 345 | rcu_read_unlock(); |
f6581f5b JH |
346 | /* |
347 | * If a task drops privileges and becomes nondumpable (through a syscall | |
348 | * like setresuid()) while we are trying to access it, we must ensure | |
349 | * that the dumpability is read after the credentials; otherwise, | |
350 | * we may be able to attach to a task that we shouldn't be able to | |
351 | * attach to (as if the task had dropped privileges without becoming | |
352 | * nondumpable). | |
353 | * Pairs with a write barrier in commit_creds(). | |
354 | */ | |
355 | smp_rmb(); | |
bfedb589 EB |
356 | mm = task->mm; |
357 | if (mm && | |
358 | ((get_dumpable(mm) != SUID_DUMP_USER) && | |
cf237052 | 359 | !ptrace_has_cap(mm->user_ns, mode))) |
bfedb589 | 360 | return -EPERM; |
ab8d11be | 361 | |
9e48858f | 362 | return security_ptrace_access_check(task, mode); |
ab8d11be MS |
363 | } |
364 | ||
006ebb40 | 365 | bool ptrace_may_access(struct task_struct *task, unsigned int mode) |
ab8d11be MS |
366 | { |
367 | int err; | |
368 | task_lock(task); | |
006ebb40 | 369 | err = __ptrace_may_access(task, mode); |
ab8d11be | 370 | task_unlock(task); |
3a709703 | 371 | return !err; |
ab8d11be MS |
372 | } |
373 | ||
3544d72a | 374 | static int ptrace_attach(struct task_struct *task, long request, |
aa9147c9 | 375 | unsigned long addr, |
3544d72a | 376 | unsigned long flags) |
1da177e4 | 377 | { |
3544d72a | 378 | bool seize = (request == PTRACE_SEIZE); |
1da177e4 | 379 | int retval; |
f5b40e36 | 380 | |
3544d72a | 381 | retval = -EIO; |
aa9147c9 DV |
382 | if (seize) { |
383 | if (addr != 0) | |
384 | goto out; | |
aa9147c9 DV |
385 | if (flags & ~(unsigned long)PTRACE_O_MASK) |
386 | goto out; | |
387 | flags = PT_PTRACED | PT_SEIZED | (flags << PT_OPT_FLAG_SHIFT); | |
388 | } else { | |
389 | flags = PT_PTRACED; | |
390 | } | |
3544d72a | 391 | |
a5cb013d AV |
392 | audit_ptrace(task); |
393 | ||
1da177e4 | 394 | retval = -EPERM; |
e8b33b8c | 395 | if (unlikely(task->flags & PF_KTHREAD)) |
b79b7ba9 | 396 | goto out; |
bac0abd6 | 397 | if (same_thread_group(task, current)) |
f5b40e36 LT |
398 | goto out; |
399 | ||
f2f0b00a ON |
400 | /* |
401 | * Protect exec's credential calculations against our interference; | |
86b6c1f3 | 402 | * SUID, SGID and LSM creds get determined differently |
5e751e99 | 403 | * under ptrace. |
d84f4f99 | 404 | */ |
793285fc | 405 | retval = -ERESTARTNOINTR; |
9b1bf12d | 406 | if (mutex_lock_interruptible(&task->signal->cred_guard_mutex)) |
d84f4f99 | 407 | goto out; |
f5b40e36 | 408 | |
4b105cbb | 409 | task_lock(task); |
caaee623 | 410 | retval = __ptrace_may_access(task, PTRACE_MODE_ATTACH_REALCREDS); |
4b105cbb | 411 | task_unlock(task); |
1da177e4 | 412 | if (retval) |
4b105cbb | 413 | goto unlock_creds; |
1da177e4 | 414 | |
4b105cbb | 415 | write_lock_irq(&tasklist_lock); |
b79b7ba9 ON |
416 | retval = -EPERM; |
417 | if (unlikely(task->exit_state)) | |
4b105cbb | 418 | goto unlock_tasklist; |
f2f0b00a | 419 | if (task->ptrace) |
4b105cbb | 420 | goto unlock_tasklist; |
b79b7ba9 | 421 | |
aa9147c9 | 422 | task->ptrace = flags; |
1da177e4 | 423 | |
c70d9d80 | 424 | ptrace_link(task, current); |
3544d72a TH |
425 | |
426 | /* SEIZE doesn't trap tracee on attach */ | |
427 | if (!seize) | |
079b22dc | 428 | send_sig_info(SIGSTOP, SEND_SIG_PRIV, task); |
b79b7ba9 | 429 | |
d79fdd6d TH |
430 | spin_lock(&task->sighand->siglock); |
431 | ||
432 | /* | |
73ddff2b | 433 | * If the task is already STOPPED, set JOBCTL_TRAP_STOP and |
d79fdd6d TH |
434 | * TRAPPING, and kick it so that it transits to TRACED. TRAPPING |
435 | * will be cleared if the child completes the transition or any | |
436 | * event which clears the group stop states happens. We'll wait | |
437 | * for the transition to complete before returning from this | |
438 | * function. | |
439 | * | |
440 | * This hides STOPPED -> RUNNING -> TRACED transition from the | |
441 | * attaching thread but a different thread in the same group can | |
442 | * still observe the transient RUNNING state. IOW, if another | |
443 | * thread's WNOHANG wait(2) on the stopped tracee races against | |
444 | * ATTACH, the wait(2) may fail due to the transient RUNNING. | |
445 | * | |
446 | * The following task_is_stopped() test is safe as both transitions | |
447 | * in and out of STOPPED are protected by siglock. | |
448 | */ | |
7dd3db54 | 449 | if (task_is_stopped(task) && |
73ddff2b | 450 | task_set_jobctl_pending(task, JOBCTL_TRAP_STOP | JOBCTL_TRAPPING)) |
910ffdb1 | 451 | signal_wake_up_state(task, __TASK_STOPPED); |
d79fdd6d TH |
452 | |
453 | spin_unlock(&task->sighand->siglock); | |
454 | ||
b79b7ba9 | 455 | retval = 0; |
4b105cbb ON |
456 | unlock_tasklist: |
457 | write_unlock_irq(&tasklist_lock); | |
458 | unlock_creds: | |
9b1bf12d | 459 | mutex_unlock(&task->signal->cred_guard_mutex); |
f5b40e36 | 460 | out: |
f701e5b7 | 461 | if (!retval) { |
7c3b00e0 ON |
462 | /* |
463 | * We do not bother to change retval or clear JOBCTL_TRAPPING | |
464 | * if wait_on_bit() was interrupted by SIGKILL. The tracer will | |
465 | * not return to user-mode, it will exit and clear this bit in | |
466 | * __ptrace_unlink() if it wasn't already cleared by the tracee; | |
467 | * and until then nobody can ptrace this task. | |
468 | */ | |
469 | wait_on_bit(&task->jobctl, JOBCTL_TRAPPING_BIT, TASK_KILLABLE); | |
f701e5b7 VZ |
470 | proc_ptrace_connector(task, PTRACE_ATTACH); |
471 | } | |
472 | ||
1da177e4 LT |
473 | return retval; |
474 | } | |
475 | ||
f2f0b00a ON |
476 | /** |
477 | * ptrace_traceme -- helper for PTRACE_TRACEME | |
478 | * | |
479 | * Performs checks and sets PT_PTRACED. | |
480 | * Should be used by all ptrace implementations for PTRACE_TRACEME. | |
481 | */ | |
e3e89cc5 | 482 | static int ptrace_traceme(void) |
f2f0b00a ON |
483 | { |
484 | int ret = -EPERM; | |
485 | ||
4b105cbb ON |
486 | write_lock_irq(&tasklist_lock); |
487 | /* Are we already being traced? */ | |
f2f0b00a | 488 | if (!current->ptrace) { |
f2f0b00a | 489 | ret = security_ptrace_traceme(current->parent); |
f2f0b00a ON |
490 | /* |
491 | * Check PF_EXITING to ensure ->real_parent has not passed | |
492 | * exit_ptrace(). Otherwise we don't report the error but | |
493 | * pretend ->real_parent untraces us right after return. | |
494 | */ | |
495 | if (!ret && !(current->real_parent->flags & PF_EXITING)) { | |
496 | current->ptrace = PT_PTRACED; | |
c70d9d80 | 497 | ptrace_link(current, current->real_parent); |
f2f0b00a | 498 | } |
f2f0b00a | 499 | } |
4b105cbb ON |
500 | write_unlock_irq(&tasklist_lock); |
501 | ||
f2f0b00a ON |
502 | return ret; |
503 | } | |
504 | ||
39c626ae ON |
505 | /* |
506 | * Called with irqs disabled, returns true if childs should reap themselves. | |
507 | */ | |
508 | static int ignoring_children(struct sighand_struct *sigh) | |
509 | { | |
510 | int ret; | |
511 | spin_lock(&sigh->siglock); | |
512 | ret = (sigh->action[SIGCHLD-1].sa.sa_handler == SIG_IGN) || | |
513 | (sigh->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT); | |
514 | spin_unlock(&sigh->siglock); | |
515 | return ret; | |
516 | } | |
517 | ||
518 | /* | |
519 | * Called with tasklist_lock held for writing. | |
520 | * Unlink a traced task, and clean it up if it was a traced zombie. | |
521 | * Return true if it needs to be reaped with release_task(). | |
522 | * (We can't call release_task() here because we already hold tasklist_lock.) | |
523 | * | |
524 | * If it's a zombie, our attachedness prevented normal parent notification | |
525 | * or self-reaping. Do notification now if it would have happened earlier. | |
526 | * If it should reap itself, return true. | |
527 | * | |
a7f0765e ON |
528 | * If it's our own child, there is no notification to do. But if our normal |
529 | * children self-reap, then this child was prevented by ptrace and we must | |
530 | * reap it now, in that case we must also wake up sub-threads sleeping in | |
531 | * do_wait(). | |
39c626ae ON |
532 | */ |
533 | static bool __ptrace_detach(struct task_struct *tracer, struct task_struct *p) | |
534 | { | |
9843a1e9 ON |
535 | bool dead; |
536 | ||
39c626ae ON |
537 | __ptrace_unlink(p); |
538 | ||
9843a1e9 ON |
539 | if (p->exit_state != EXIT_ZOMBIE) |
540 | return false; | |
541 | ||
542 | dead = !thread_group_leader(p); | |
543 | ||
544 | if (!dead && thread_group_empty(p)) { | |
545 | if (!same_thread_group(p->real_parent, tracer)) | |
546 | dead = do_notify_parent(p, p->exit_signal); | |
547 | else if (ignoring_children(tracer->sighand)) { | |
548 | __wake_up_parent(p, tracer); | |
9843a1e9 | 549 | dead = true; |
39c626ae ON |
550 | } |
551 | } | |
9843a1e9 ON |
552 | /* Mark it as in the process of being reaped. */ |
553 | if (dead) | |
554 | p->exit_state = EXIT_DEAD; | |
555 | return dead; | |
39c626ae ON |
556 | } |
557 | ||
e3e89cc5 | 558 | static int ptrace_detach(struct task_struct *child, unsigned int data) |
1da177e4 | 559 | { |
7ed20e1a | 560 | if (!valid_signal(data)) |
5ecfbae0 | 561 | return -EIO; |
1da177e4 LT |
562 | |
563 | /* Architecture-specific hardware disable .. */ | |
564 | ptrace_disable(child); | |
565 | ||
95c3eb76 | 566 | write_lock_irq(&tasklist_lock); |
39c626ae | 567 | /* |
64a4096c ON |
568 | * We rely on ptrace_freeze_traced(). It can't be killed and |
569 | * untraced by another thread, it can't be a zombie. | |
39c626ae | 570 | */ |
64a4096c ON |
571 | WARN_ON(!child->ptrace || child->exit_state); |
572 | /* | |
573 | * tasklist_lock avoids the race with wait_task_stopped(), see | |
574 | * the comment in ptrace_resume(). | |
575 | */ | |
576 | child->exit_code = data; | |
577 | __ptrace_detach(current, child); | |
1da177e4 LT |
578 | write_unlock_irq(&tasklist_lock); |
579 | ||
f701e5b7 | 580 | proc_ptrace_connector(child, PTRACE_DETACH); |
4576145c | 581 | |
1da177e4 LT |
582 | return 0; |
583 | } | |
584 | ||
39c626ae | 585 | /* |
c7e49c14 | 586 | * Detach all tasks we were using ptrace on. Called with tasklist held |
7c8bd232 | 587 | * for writing. |
39c626ae | 588 | */ |
7c8bd232 | 589 | void exit_ptrace(struct task_struct *tracer, struct list_head *dead) |
39c626ae ON |
590 | { |
591 | struct task_struct *p, *n; | |
c7e49c14 | 592 | |
39c626ae | 593 | list_for_each_entry_safe(p, n, &tracer->ptraced, ptrace_entry) { |
992fb6e1 | 594 | if (unlikely(p->ptrace & PT_EXITKILL)) |
079b22dc | 595 | send_sig_info(SIGKILL, SEND_SIG_PRIV, p); |
992fb6e1 | 596 | |
39c626ae | 597 | if (__ptrace_detach(tracer, p)) |
7c8bd232 | 598 | list_add(&p->ptrace_entry, dead); |
39c626ae ON |
599 | } |
600 | } | |
601 | ||
1da177e4 LT |
602 | int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len) |
603 | { | |
604 | int copied = 0; | |
605 | ||
606 | while (len > 0) { | |
607 | char buf[128]; | |
608 | int this_len, retval; | |
609 | ||
610 | this_len = (len > sizeof(buf)) ? sizeof(buf) : len; | |
84d77d3f EB |
611 | retval = ptrace_access_vm(tsk, src, buf, this_len, FOLL_FORCE); |
612 | ||
1da177e4 LT |
613 | if (!retval) { |
614 | if (copied) | |
615 | break; | |
616 | return -EIO; | |
617 | } | |
618 | if (copy_to_user(dst, buf, retval)) | |
619 | return -EFAULT; | |
620 | copied += retval; | |
621 | src += retval; | |
622 | dst += retval; | |
3a709703 | 623 | len -= retval; |
1da177e4 LT |
624 | } |
625 | return copied; | |
626 | } | |
627 | ||
628 | int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len) | |
629 | { | |
630 | int copied = 0; | |
631 | ||
632 | while (len > 0) { | |
633 | char buf[128]; | |
634 | int this_len, retval; | |
635 | ||
636 | this_len = (len > sizeof(buf)) ? sizeof(buf) : len; | |
637 | if (copy_from_user(buf, src, this_len)) | |
638 | return -EFAULT; | |
84d77d3f | 639 | retval = ptrace_access_vm(tsk, dst, buf, this_len, |
f307ab6d | 640 | FOLL_FORCE | FOLL_WRITE); |
1da177e4 LT |
641 | if (!retval) { |
642 | if (copied) | |
643 | break; | |
644 | return -EIO; | |
645 | } | |
646 | copied += retval; | |
647 | src += retval; | |
648 | dst += retval; | |
3a709703 | 649 | len -= retval; |
1da177e4 LT |
650 | } |
651 | return copied; | |
652 | } | |
653 | ||
4abf9869 | 654 | static int ptrace_setoptions(struct task_struct *child, unsigned long data) |
1da177e4 | 655 | { |
86b6c1f3 DV |
656 | unsigned flags; |
657 | ||
8c5cf9e5 DV |
658 | if (data & ~(unsigned long)PTRACE_O_MASK) |
659 | return -EINVAL; | |
660 | ||
13c4a901 | 661 | if (unlikely(data & PTRACE_O_SUSPEND_SECCOMP)) { |
97f2645f MY |
662 | if (!IS_ENABLED(CONFIG_CHECKPOINT_RESTORE) || |
663 | !IS_ENABLED(CONFIG_SECCOMP)) | |
13c4a901 TA |
664 | return -EINVAL; |
665 | ||
666 | if (!capable(CAP_SYS_ADMIN)) | |
667 | return -EPERM; | |
668 | ||
669 | if (seccomp_mode(¤t->seccomp) != SECCOMP_MODE_DISABLED || | |
670 | current->ptrace & PT_SUSPEND_SECCOMP) | |
671 | return -EPERM; | |
672 | } | |
673 | ||
86b6c1f3 DV |
674 | /* Avoid intermediate state when all opts are cleared */ |
675 | flags = child->ptrace; | |
676 | flags &= ~(PTRACE_O_MASK << PT_OPT_FLAG_SHIFT); | |
677 | flags |= (data << PT_OPT_FLAG_SHIFT); | |
678 | child->ptrace = flags; | |
1da177e4 | 679 | |
8c5cf9e5 | 680 | return 0; |
1da177e4 LT |
681 | } |
682 | ||
ae7795bc | 683 | static int ptrace_getsiginfo(struct task_struct *child, kernel_siginfo_t *info) |
1da177e4 | 684 | { |
e4961254 | 685 | unsigned long flags; |
1da177e4 LT |
686 | int error = -ESRCH; |
687 | ||
e4961254 | 688 | if (lock_task_sighand(child, &flags)) { |
1da177e4 | 689 | error = -EINVAL; |
1da177e4 | 690 | if (likely(child->last_siginfo != NULL)) { |
0752d7bf | 691 | copy_siginfo(info, child->last_siginfo); |
1da177e4 LT |
692 | error = 0; |
693 | } | |
e4961254 | 694 | unlock_task_sighand(child, &flags); |
1da177e4 | 695 | } |
1da177e4 LT |
696 | return error; |
697 | } | |
698 | ||
ae7795bc | 699 | static int ptrace_setsiginfo(struct task_struct *child, const kernel_siginfo_t *info) |
1da177e4 | 700 | { |
e4961254 | 701 | unsigned long flags; |
1da177e4 LT |
702 | int error = -ESRCH; |
703 | ||
e4961254 | 704 | if (lock_task_sighand(child, &flags)) { |
1da177e4 | 705 | error = -EINVAL; |
1da177e4 | 706 | if (likely(child->last_siginfo != NULL)) { |
0752d7bf | 707 | copy_siginfo(child->last_siginfo, info); |
1da177e4 LT |
708 | error = 0; |
709 | } | |
e4961254 | 710 | unlock_task_sighand(child, &flags); |
1da177e4 | 711 | } |
1da177e4 LT |
712 | return error; |
713 | } | |
714 | ||
84c751bd AV |
715 | static int ptrace_peek_siginfo(struct task_struct *child, |
716 | unsigned long addr, | |
717 | unsigned long data) | |
718 | { | |
719 | struct ptrace_peeksiginfo_args arg; | |
720 | struct sigpending *pending; | |
721 | struct sigqueue *q; | |
722 | int ret, i; | |
723 | ||
724 | ret = copy_from_user(&arg, (void __user *) addr, | |
725 | sizeof(struct ptrace_peeksiginfo_args)); | |
726 | if (ret) | |
727 | return -EFAULT; | |
728 | ||
729 | if (arg.flags & ~PTRACE_PEEKSIGINFO_SHARED) | |
730 | return -EINVAL; /* unknown flags */ | |
731 | ||
732 | if (arg.nr < 0) | |
733 | return -EINVAL; | |
734 | ||
f6e2aa91 EB |
735 | /* Ensure arg.off fits in an unsigned long */ |
736 | if (arg.off > ULONG_MAX) | |
737 | return 0; | |
738 | ||
84c751bd AV |
739 | if (arg.flags & PTRACE_PEEKSIGINFO_SHARED) |
740 | pending = &child->signal->shared_pending; | |
741 | else | |
742 | pending = &child->pending; | |
743 | ||
744 | for (i = 0; i < arg.nr; ) { | |
ae7795bc | 745 | kernel_siginfo_t info; |
f6e2aa91 EB |
746 | unsigned long off = arg.off + i; |
747 | bool found = false; | |
84c751bd AV |
748 | |
749 | spin_lock_irq(&child->sighand->siglock); | |
750 | list_for_each_entry(q, &pending->list, list) { | |
751 | if (!off--) { | |
f6e2aa91 | 752 | found = true; |
84c751bd AV |
753 | copy_siginfo(&info, &q->info); |
754 | break; | |
755 | } | |
756 | } | |
757 | spin_unlock_irq(&child->sighand->siglock); | |
758 | ||
f6e2aa91 | 759 | if (!found) /* beyond the end of the list */ |
84c751bd AV |
760 | break; |
761 | ||
762 | #ifdef CONFIG_COMPAT | |
5c465217 | 763 | if (unlikely(in_compat_syscall())) { |
84c751bd AV |
764 | compat_siginfo_t __user *uinfo = compat_ptr(data); |
765 | ||
cc731525 | 766 | if (copy_siginfo_to_user32(uinfo, &info)) { |
706b23bd MD |
767 | ret = -EFAULT; |
768 | break; | |
769 | } | |
770 | ||
84c751bd AV |
771 | } else |
772 | #endif | |
773 | { | |
774 | siginfo_t __user *uinfo = (siginfo_t __user *) data; | |
775 | ||
cc731525 | 776 | if (copy_siginfo_to_user(uinfo, &info)) { |
706b23bd MD |
777 | ret = -EFAULT; |
778 | break; | |
779 | } | |
84c751bd AV |
780 | } |
781 | ||
782 | data += sizeof(siginfo_t); | |
783 | i++; | |
784 | ||
785 | if (signal_pending(current)) | |
786 | break; | |
787 | ||
788 | cond_resched(); | |
789 | } | |
790 | ||
791 | if (i > 0) | |
792 | return i; | |
793 | ||
794 | return ret; | |
795 | } | |
36df29d7 | 796 | |
90f093fa PF |
797 | #ifdef CONFIG_RSEQ |
798 | static long ptrace_get_rseq_configuration(struct task_struct *task, | |
799 | unsigned long size, void __user *data) | |
800 | { | |
801 | struct ptrace_rseq_configuration conf = { | |
802 | .rseq_abi_pointer = (u64)(uintptr_t)task->rseq, | |
803 | .rseq_abi_size = sizeof(*task->rseq), | |
804 | .signature = task->rseq_sig, | |
805 | .flags = 0, | |
806 | }; | |
807 | ||
808 | size = min_t(unsigned long, size, sizeof(conf)); | |
809 | if (copy_to_user(data, &conf, size)) | |
810 | return -EFAULT; | |
811 | return sizeof(conf); | |
812 | } | |
813 | #endif | |
814 | ||
36df29d7 RM |
815 | #ifdef PTRACE_SINGLESTEP |
816 | #define is_singlestep(request) ((request) == PTRACE_SINGLESTEP) | |
817 | #else | |
818 | #define is_singlestep(request) 0 | |
819 | #endif | |
820 | ||
5b88abbf RM |
821 | #ifdef PTRACE_SINGLEBLOCK |
822 | #define is_singleblock(request) ((request) == PTRACE_SINGLEBLOCK) | |
823 | #else | |
824 | #define is_singleblock(request) 0 | |
825 | #endif | |
826 | ||
36df29d7 RM |
827 | #ifdef PTRACE_SYSEMU |
828 | #define is_sysemu_singlestep(request) ((request) == PTRACE_SYSEMU_SINGLESTEP) | |
829 | #else | |
830 | #define is_sysemu_singlestep(request) 0 | |
831 | #endif | |
832 | ||
4abf9869 NK |
833 | static int ptrace_resume(struct task_struct *child, long request, |
834 | unsigned long data) | |
36df29d7 | 835 | { |
b72c1869 ON |
836 | bool need_siglock; |
837 | ||
36df29d7 RM |
838 | if (!valid_signal(data)) |
839 | return -EIO; | |
840 | ||
841 | if (request == PTRACE_SYSCALL) | |
64c19ba2 | 842 | set_task_syscall_work(child, SYSCALL_TRACE); |
36df29d7 | 843 | else |
64c19ba2 | 844 | clear_task_syscall_work(child, SYSCALL_TRACE); |
36df29d7 | 845 | |
64eb35f7 | 846 | #if defined(CONFIG_GENERIC_ENTRY) || defined(TIF_SYSCALL_EMU) |
36df29d7 | 847 | if (request == PTRACE_SYSEMU || request == PTRACE_SYSEMU_SINGLESTEP) |
64eb35f7 | 848 | set_task_syscall_work(child, SYSCALL_EMU); |
36df29d7 | 849 | else |
64eb35f7 | 850 | clear_task_syscall_work(child, SYSCALL_EMU); |
36df29d7 RM |
851 | #endif |
852 | ||
5b88abbf RM |
853 | if (is_singleblock(request)) { |
854 | if (unlikely(!arch_has_block_step())) | |
855 | return -EIO; | |
856 | user_enable_block_step(child); | |
857 | } else if (is_singlestep(request) || is_sysemu_singlestep(request)) { | |
36df29d7 RM |
858 | if (unlikely(!arch_has_single_step())) |
859 | return -EIO; | |
860 | user_enable_single_step(child); | |
3a709703 | 861 | } else { |
36df29d7 | 862 | user_disable_single_step(child); |
3a709703 | 863 | } |
36df29d7 | 864 | |
b72c1869 ON |
865 | /* |
866 | * Change ->exit_code and ->state under siglock to avoid the race | |
867 | * with wait_task_stopped() in between; a non-zero ->exit_code will | |
868 | * wrongly look like another report from tracee. | |
869 | * | |
870 | * Note that we need siglock even if ->exit_code == data and/or this | |
871 | * status was not reported yet, the new status must not be cleared by | |
872 | * wait_task_stopped() after resume. | |
873 | * | |
874 | * If data == 0 we do not care if wait_task_stopped() reports the old | |
875 | * status and clears the code too; this can't race with the tracee, it | |
876 | * takes siglock after resume. | |
877 | */ | |
878 | need_siglock = data && !thread_group_empty(current); | |
879 | if (need_siglock) | |
880 | spin_lock_irq(&child->sighand->siglock); | |
36df29d7 | 881 | child->exit_code = data; |
0666fb51 | 882 | wake_up_state(child, __TASK_TRACED); |
b72c1869 ON |
883 | if (need_siglock) |
884 | spin_unlock_irq(&child->sighand->siglock); | |
36df29d7 RM |
885 | |
886 | return 0; | |
887 | } | |
888 | ||
2225a122 SS |
889 | #ifdef CONFIG_HAVE_ARCH_TRACEHOOK |
890 | ||
891 | static const struct user_regset * | |
892 | find_regset(const struct user_regset_view *view, unsigned int type) | |
893 | { | |
894 | const struct user_regset *regset; | |
895 | int n; | |
896 | ||
897 | for (n = 0; n < view->n; ++n) { | |
898 | regset = view->regsets + n; | |
899 | if (regset->core_note_type == type) | |
900 | return regset; | |
901 | } | |
902 | ||
903 | return NULL; | |
904 | } | |
905 | ||
906 | static int ptrace_regset(struct task_struct *task, int req, unsigned int type, | |
907 | struct iovec *kiov) | |
908 | { | |
909 | const struct user_regset_view *view = task_user_regset_view(task); | |
910 | const struct user_regset *regset = find_regset(view, type); | |
911 | int regset_no; | |
912 | ||
913 | if (!regset || (kiov->iov_len % regset->size) != 0) | |
c6a0dd7e | 914 | return -EINVAL; |
2225a122 SS |
915 | |
916 | regset_no = regset - view->regsets; | |
917 | kiov->iov_len = min(kiov->iov_len, | |
918 | (__kernel_size_t) (regset->n * regset->size)); | |
919 | ||
920 | if (req == PTRACE_GETREGSET) | |
921 | return copy_regset_to_user(task, view, regset_no, 0, | |
922 | kiov->iov_len, kiov->iov_base); | |
923 | else | |
924 | return copy_regset_from_user(task, view, regset_no, 0, | |
925 | kiov->iov_len, kiov->iov_base); | |
926 | } | |
927 | ||
e8440c14 JS |
928 | /* |
929 | * This is declared in linux/regset.h and defined in machine-dependent | |
930 | * code. We put the export here, near the primary machine-neutral use, | |
931 | * to ensure no machine forgets it. | |
932 | */ | |
933 | EXPORT_SYMBOL_GPL(task_user_regset_view); | |
201766a2 EK |
934 | |
935 | static unsigned long | |
936 | ptrace_get_syscall_info_entry(struct task_struct *child, struct pt_regs *regs, | |
937 | struct ptrace_syscall_info *info) | |
938 | { | |
939 | unsigned long args[ARRAY_SIZE(info->entry.args)]; | |
940 | int i; | |
941 | ||
942 | info->op = PTRACE_SYSCALL_INFO_ENTRY; | |
943 | info->entry.nr = syscall_get_nr(child, regs); | |
944 | syscall_get_arguments(child, regs, args); | |
945 | for (i = 0; i < ARRAY_SIZE(args); i++) | |
946 | info->entry.args[i] = args[i]; | |
947 | ||
948 | /* args is the last field in struct ptrace_syscall_info.entry */ | |
949 | return offsetofend(struct ptrace_syscall_info, entry.args); | |
950 | } | |
951 | ||
952 | static unsigned long | |
953 | ptrace_get_syscall_info_seccomp(struct task_struct *child, struct pt_regs *regs, | |
954 | struct ptrace_syscall_info *info) | |
955 | { | |
956 | /* | |
957 | * As struct ptrace_syscall_info.entry is currently a subset | |
958 | * of struct ptrace_syscall_info.seccomp, it makes sense to | |
959 | * initialize that subset using ptrace_get_syscall_info_entry(). | |
960 | * This can be reconsidered in the future if these structures | |
961 | * diverge significantly enough. | |
962 | */ | |
963 | ptrace_get_syscall_info_entry(child, regs, info); | |
964 | info->op = PTRACE_SYSCALL_INFO_SECCOMP; | |
965 | info->seccomp.ret_data = child->ptrace_message; | |
966 | ||
967 | /* ret_data is the last field in struct ptrace_syscall_info.seccomp */ | |
968 | return offsetofend(struct ptrace_syscall_info, seccomp.ret_data); | |
969 | } | |
970 | ||
971 | static unsigned long | |
972 | ptrace_get_syscall_info_exit(struct task_struct *child, struct pt_regs *regs, | |
973 | struct ptrace_syscall_info *info) | |
974 | { | |
975 | info->op = PTRACE_SYSCALL_INFO_EXIT; | |
976 | info->exit.rval = syscall_get_error(child, regs); | |
977 | info->exit.is_error = !!info->exit.rval; | |
978 | if (!info->exit.is_error) | |
979 | info->exit.rval = syscall_get_return_value(child, regs); | |
980 | ||
981 | /* is_error is the last field in struct ptrace_syscall_info.exit */ | |
982 | return offsetofend(struct ptrace_syscall_info, exit.is_error); | |
983 | } | |
984 | ||
985 | static int | |
986 | ptrace_get_syscall_info(struct task_struct *child, unsigned long user_size, | |
987 | void __user *datavp) | |
988 | { | |
989 | struct pt_regs *regs = task_pt_regs(child); | |
990 | struct ptrace_syscall_info info = { | |
991 | .op = PTRACE_SYSCALL_INFO_NONE, | |
992 | .arch = syscall_get_arch(child), | |
993 | .instruction_pointer = instruction_pointer(regs), | |
994 | .stack_pointer = user_stack_pointer(regs), | |
995 | }; | |
996 | unsigned long actual_size = offsetof(struct ptrace_syscall_info, entry); | |
997 | unsigned long write_size; | |
998 | ||
999 | /* | |
1000 | * This does not need lock_task_sighand() to access | |
1001 | * child->last_siginfo because ptrace_freeze_traced() | |
1002 | * called earlier by ptrace_check_attach() ensures that | |
1003 | * the tracee cannot go away and clear its last_siginfo. | |
1004 | */ | |
1005 | switch (child->last_siginfo ? child->last_siginfo->si_code : 0) { | |
1006 | case SIGTRAP | 0x80: | |
1007 | switch (child->ptrace_message) { | |
1008 | case PTRACE_EVENTMSG_SYSCALL_ENTRY: | |
1009 | actual_size = ptrace_get_syscall_info_entry(child, regs, | |
1010 | &info); | |
1011 | break; | |
1012 | case PTRACE_EVENTMSG_SYSCALL_EXIT: | |
1013 | actual_size = ptrace_get_syscall_info_exit(child, regs, | |
1014 | &info); | |
1015 | break; | |
1016 | } | |
1017 | break; | |
1018 | case SIGTRAP | (PTRACE_EVENT_SECCOMP << 8): | |
1019 | actual_size = ptrace_get_syscall_info_seccomp(child, regs, | |
1020 | &info); | |
1021 | break; | |
1022 | } | |
1023 | ||
1024 | write_size = min(actual_size, user_size); | |
1025 | return copy_to_user(datavp, &info, write_size) ? -EFAULT : actual_size; | |
1026 | } | |
1027 | #endif /* CONFIG_HAVE_ARCH_TRACEHOOK */ | |
2225a122 | 1028 | |
1da177e4 | 1029 | int ptrace_request(struct task_struct *child, long request, |
4abf9869 | 1030 | unsigned long addr, unsigned long data) |
1da177e4 | 1031 | { |
fca26f26 | 1032 | bool seized = child->ptrace & PT_SEIZED; |
1da177e4 | 1033 | int ret = -EIO; |
ae7795bc | 1034 | kernel_siginfo_t siginfo, *si; |
9fed81dc NK |
1035 | void __user *datavp = (void __user *) data; |
1036 | unsigned long __user *datalp = datavp; | |
fca26f26 | 1037 | unsigned long flags; |
1da177e4 LT |
1038 | |
1039 | switch (request) { | |
16c3e389 RM |
1040 | case PTRACE_PEEKTEXT: |
1041 | case PTRACE_PEEKDATA: | |
1042 | return generic_ptrace_peekdata(child, addr, data); | |
1043 | case PTRACE_POKETEXT: | |
1044 | case PTRACE_POKEDATA: | |
1045 | return generic_ptrace_pokedata(child, addr, data); | |
1046 | ||
1da177e4 LT |
1047 | #ifdef PTRACE_OLDSETOPTIONS |
1048 | case PTRACE_OLDSETOPTIONS: | |
1049 | #endif | |
1050 | case PTRACE_SETOPTIONS: | |
1051 | ret = ptrace_setoptions(child, data); | |
1052 | break; | |
1053 | case PTRACE_GETEVENTMSG: | |
9fed81dc | 1054 | ret = put_user(child->ptrace_message, datalp); |
1da177e4 | 1055 | break; |
e16b2781 | 1056 | |
84c751bd AV |
1057 | case PTRACE_PEEKSIGINFO: |
1058 | ret = ptrace_peek_siginfo(child, addr, data); | |
1059 | break; | |
1060 | ||
1da177e4 | 1061 | case PTRACE_GETSIGINFO: |
e16b2781 RM |
1062 | ret = ptrace_getsiginfo(child, &siginfo); |
1063 | if (!ret) | |
9fed81dc | 1064 | ret = copy_siginfo_to_user(datavp, &siginfo); |
1da177e4 | 1065 | break; |
e16b2781 | 1066 | |
1da177e4 | 1067 | case PTRACE_SETSIGINFO: |
4cd2e0e7 EB |
1068 | ret = copy_siginfo_from_user(&siginfo, datavp); |
1069 | if (!ret) | |
e16b2781 | 1070 | ret = ptrace_setsiginfo(child, &siginfo); |
1da177e4 | 1071 | break; |
e16b2781 | 1072 | |
fcfc2aa0 AV |
1073 | case PTRACE_GETSIGMASK: { |
1074 | sigset_t *mask; | |
1075 | ||
29000cae AV |
1076 | if (addr != sizeof(sigset_t)) { |
1077 | ret = -EINVAL; | |
1078 | break; | |
1079 | } | |
1080 | ||
fcfc2aa0 AV |
1081 | if (test_tsk_restore_sigmask(child)) |
1082 | mask = &child->saved_sigmask; | |
1083 | else | |
1084 | mask = &child->blocked; | |
1085 | ||
1086 | if (copy_to_user(datavp, mask, sizeof(sigset_t))) | |
29000cae AV |
1087 | ret = -EFAULT; |
1088 | else | |
1089 | ret = 0; | |
1090 | ||
1091 | break; | |
fcfc2aa0 | 1092 | } |
29000cae AV |
1093 | |
1094 | case PTRACE_SETSIGMASK: { | |
1095 | sigset_t new_set; | |
1096 | ||
1097 | if (addr != sizeof(sigset_t)) { | |
1098 | ret = -EINVAL; | |
1099 | break; | |
1100 | } | |
1101 | ||
1102 | if (copy_from_user(&new_set, datavp, sizeof(sigset_t))) { | |
1103 | ret = -EFAULT; | |
1104 | break; | |
1105 | } | |
1106 | ||
1107 | sigdelsetmask(&new_set, sigmask(SIGKILL)|sigmask(SIGSTOP)); | |
1108 | ||
1109 | /* | |
1110 | * Every thread does recalc_sigpending() after resume, so | |
1111 | * retarget_shared_pending() and recalc_sigpending() are not | |
1112 | * called here. | |
1113 | */ | |
1114 | spin_lock_irq(&child->sighand->siglock); | |
1115 | child->blocked = new_set; | |
1116 | spin_unlock_irq(&child->sighand->siglock); | |
1117 | ||
fcfc2aa0 AV |
1118 | clear_tsk_restore_sigmask(child); |
1119 | ||
29000cae AV |
1120 | ret = 0; |
1121 | break; | |
1122 | } | |
1123 | ||
fca26f26 TH |
1124 | case PTRACE_INTERRUPT: |
1125 | /* | |
1126 | * Stop tracee without any side-effect on signal or job | |
1127 | * control. At least one trap is guaranteed to happen | |
1128 | * after this request. If @child is already trapped, the | |
1129 | * current trap is not disturbed and another trap will | |
1130 | * happen after the current trap is ended with PTRACE_CONT. | |
1131 | * | |
1132 | * The actual trap might not be PTRACE_EVENT_STOP trap but | |
1133 | * the pending condition is cleared regardless. | |
1134 | */ | |
1135 | if (unlikely(!seized || !lock_task_sighand(child, &flags))) | |
1136 | break; | |
1137 | ||
544b2c91 TH |
1138 | /* |
1139 | * INTERRUPT doesn't disturb existing trap sans one | |
1140 | * exception. If ptracer issued LISTEN for the current | |
1141 | * STOP, this INTERRUPT should clear LISTEN and re-trap | |
1142 | * tracee into STOP. | |
1143 | */ | |
fca26f26 | 1144 | if (likely(task_set_jobctl_pending(child, JOBCTL_TRAP_STOP))) |
910ffdb1 | 1145 | ptrace_signal_wake_up(child, child->jobctl & JOBCTL_LISTENING); |
544b2c91 TH |
1146 | |
1147 | unlock_task_sighand(child, &flags); | |
1148 | ret = 0; | |
1149 | break; | |
1150 | ||
1151 | case PTRACE_LISTEN: | |
1152 | /* | |
1153 | * Listen for events. Tracee must be in STOP. It's not | |
1154 | * resumed per-se but is not considered to be in TRACED by | |
1155 | * wait(2) or ptrace(2). If an async event (e.g. group | |
1156 | * stop state change) happens, tracee will enter STOP trap | |
1157 | * again. Alternatively, ptracer can issue INTERRUPT to | |
1158 | * finish listening and re-trap tracee into STOP. | |
1159 | */ | |
1160 | if (unlikely(!seized || !lock_task_sighand(child, &flags))) | |
1161 | break; | |
1162 | ||
1163 | si = child->last_siginfo; | |
f9d81f61 ON |
1164 | if (likely(si && (si->si_code >> 8) == PTRACE_EVENT_STOP)) { |
1165 | child->jobctl |= JOBCTL_LISTENING; | |
1166 | /* | |
1167 | * If NOTIFY is set, it means event happened between | |
1168 | * start of this trap and now. Trigger re-trap. | |
1169 | */ | |
1170 | if (child->jobctl & JOBCTL_TRAP_NOTIFY) | |
910ffdb1 | 1171 | ptrace_signal_wake_up(child, true); |
f9d81f61 ON |
1172 | ret = 0; |
1173 | } | |
fca26f26 | 1174 | unlock_task_sighand(child, &flags); |
fca26f26 TH |
1175 | break; |
1176 | ||
1bcf5482 AD |
1177 | case PTRACE_DETACH: /* detach a process that was attached. */ |
1178 | ret = ptrace_detach(child, data); | |
1179 | break; | |
36df29d7 | 1180 | |
9c1a1259 MF |
1181 | #ifdef CONFIG_BINFMT_ELF_FDPIC |
1182 | case PTRACE_GETFDPIC: { | |
e0129ef9 | 1183 | struct mm_struct *mm = get_task_mm(child); |
9c1a1259 MF |
1184 | unsigned long tmp = 0; |
1185 | ||
e0129ef9 ON |
1186 | ret = -ESRCH; |
1187 | if (!mm) | |
1188 | break; | |
1189 | ||
9c1a1259 MF |
1190 | switch (addr) { |
1191 | case PTRACE_GETFDPIC_EXEC: | |
e0129ef9 | 1192 | tmp = mm->context.exec_fdpic_loadmap; |
9c1a1259 MF |
1193 | break; |
1194 | case PTRACE_GETFDPIC_INTERP: | |
e0129ef9 | 1195 | tmp = mm->context.interp_fdpic_loadmap; |
9c1a1259 MF |
1196 | break; |
1197 | default: | |
1198 | break; | |
1199 | } | |
e0129ef9 | 1200 | mmput(mm); |
9c1a1259 | 1201 | |
9fed81dc | 1202 | ret = put_user(tmp, datalp); |
9c1a1259 MF |
1203 | break; |
1204 | } | |
1205 | #endif | |
1206 | ||
36df29d7 RM |
1207 | #ifdef PTRACE_SINGLESTEP |
1208 | case PTRACE_SINGLESTEP: | |
1209 | #endif | |
5b88abbf RM |
1210 | #ifdef PTRACE_SINGLEBLOCK |
1211 | case PTRACE_SINGLEBLOCK: | |
1212 | #endif | |
36df29d7 RM |
1213 | #ifdef PTRACE_SYSEMU |
1214 | case PTRACE_SYSEMU: | |
1215 | case PTRACE_SYSEMU_SINGLESTEP: | |
1216 | #endif | |
1217 | case PTRACE_SYSCALL: | |
1218 | case PTRACE_CONT: | |
1219 | return ptrace_resume(child, request, data); | |
1220 | ||
1221 | case PTRACE_KILL: | |
1222 | if (child->exit_state) /* already dead */ | |
1223 | return 0; | |
1224 | return ptrace_resume(child, request, SIGKILL); | |
1225 | ||
2225a122 SS |
1226 | #ifdef CONFIG_HAVE_ARCH_TRACEHOOK |
1227 | case PTRACE_GETREGSET: | |
29000cae | 1228 | case PTRACE_SETREGSET: { |
2225a122 | 1229 | struct iovec kiov; |
9fed81dc | 1230 | struct iovec __user *uiov = datavp; |
2225a122 | 1231 | |
96d4f267 | 1232 | if (!access_ok(uiov, sizeof(*uiov))) |
2225a122 SS |
1233 | return -EFAULT; |
1234 | ||
1235 | if (__get_user(kiov.iov_base, &uiov->iov_base) || | |
1236 | __get_user(kiov.iov_len, &uiov->iov_len)) | |
1237 | return -EFAULT; | |
1238 | ||
1239 | ret = ptrace_regset(child, request, addr, &kiov); | |
1240 | if (!ret) | |
1241 | ret = __put_user(kiov.iov_len, &uiov->iov_len); | |
1242 | break; | |
1243 | } | |
201766a2 EK |
1244 | |
1245 | case PTRACE_GET_SYSCALL_INFO: | |
1246 | ret = ptrace_get_syscall_info(child, addr, datavp); | |
1247 | break; | |
2225a122 | 1248 | #endif |
f8e529ed TA |
1249 | |
1250 | case PTRACE_SECCOMP_GET_FILTER: | |
1251 | ret = seccomp_get_filter(child, addr, datavp); | |
1252 | break; | |
1253 | ||
26500475 TA |
1254 | case PTRACE_SECCOMP_GET_METADATA: |
1255 | ret = seccomp_get_metadata(child, addr, datavp); | |
1256 | break; | |
1257 | ||
90f093fa PF |
1258 | #ifdef CONFIG_RSEQ |
1259 | case PTRACE_GET_RSEQ_CONFIGURATION: | |
1260 | ret = ptrace_get_rseq_configuration(child, addr, datavp); | |
1261 | break; | |
1262 | #endif | |
1263 | ||
1da177e4 LT |
1264 | default: |
1265 | break; | |
1266 | } | |
1267 | ||
1268 | return ret; | |
1269 | } | |
481bed45 | 1270 | |
0ac15559 CH |
1271 | #ifndef arch_ptrace_attach |
1272 | #define arch_ptrace_attach(child) do { } while (0) | |
1273 | #endif | |
1274 | ||
4abf9869 NK |
1275 | SYSCALL_DEFINE4(ptrace, long, request, long, pid, unsigned long, addr, |
1276 | unsigned long, data) | |
481bed45 CH |
1277 | { |
1278 | struct task_struct *child; | |
1279 | long ret; | |
1280 | ||
6b9c7ed8 CH |
1281 | if (request == PTRACE_TRACEME) { |
1282 | ret = ptrace_traceme(); | |
6ea6dd93 HS |
1283 | if (!ret) |
1284 | arch_ptrace_attach(current); | |
481bed45 | 1285 | goto out; |
6b9c7ed8 CH |
1286 | } |
1287 | ||
2ee08260 MR |
1288 | child = find_get_task_by_vpid(pid); |
1289 | if (!child) { | |
1290 | ret = -ESRCH; | |
6b9c7ed8 CH |
1291 | goto out; |
1292 | } | |
481bed45 | 1293 | |
3544d72a | 1294 | if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) { |
aa9147c9 | 1295 | ret = ptrace_attach(child, request, addr, data); |
0ac15559 CH |
1296 | /* |
1297 | * Some architectures need to do book-keeping after | |
1298 | * a ptrace attach. | |
1299 | */ | |
1300 | if (!ret) | |
1301 | arch_ptrace_attach(child); | |
005f18df | 1302 | goto out_put_task_struct; |
481bed45 CH |
1303 | } |
1304 | ||
fca26f26 TH |
1305 | ret = ptrace_check_attach(child, request == PTRACE_KILL || |
1306 | request == PTRACE_INTERRUPT); | |
481bed45 CH |
1307 | if (ret < 0) |
1308 | goto out_put_task_struct; | |
1309 | ||
1310 | ret = arch_ptrace(child, request, addr, data); | |
9899d11f ON |
1311 | if (ret || request != PTRACE_DETACH) |
1312 | ptrace_unfreeze_traced(child); | |
481bed45 CH |
1313 | |
1314 | out_put_task_struct: | |
1315 | put_task_struct(child); | |
1316 | out: | |
481bed45 CH |
1317 | return ret; |
1318 | } | |
76647323 | 1319 | |
4abf9869 NK |
1320 | int generic_ptrace_peekdata(struct task_struct *tsk, unsigned long addr, |
1321 | unsigned long data) | |
76647323 AD |
1322 | { |
1323 | unsigned long tmp; | |
1324 | int copied; | |
1325 | ||
84d77d3f | 1326 | copied = ptrace_access_vm(tsk, addr, &tmp, sizeof(tmp), FOLL_FORCE); |
76647323 AD |
1327 | if (copied != sizeof(tmp)) |
1328 | return -EIO; | |
1329 | return put_user(tmp, (unsigned long __user *)data); | |
1330 | } | |
f284ce72 | 1331 | |
4abf9869 NK |
1332 | int generic_ptrace_pokedata(struct task_struct *tsk, unsigned long addr, |
1333 | unsigned long data) | |
f284ce72 AD |
1334 | { |
1335 | int copied; | |
1336 | ||
84d77d3f | 1337 | copied = ptrace_access_vm(tsk, addr, &data, sizeof(data), |
f307ab6d | 1338 | FOLL_FORCE | FOLL_WRITE); |
f284ce72 AD |
1339 | return (copied == sizeof(data)) ? 0 : -EIO; |
1340 | } | |
032d82d9 | 1341 | |
96b8936a | 1342 | #if defined CONFIG_COMPAT |
032d82d9 RM |
1343 | |
1344 | int compat_ptrace_request(struct task_struct *child, compat_long_t request, | |
1345 | compat_ulong_t addr, compat_ulong_t data) | |
1346 | { | |
1347 | compat_ulong_t __user *datap = compat_ptr(data); | |
1348 | compat_ulong_t word; | |
ae7795bc | 1349 | kernel_siginfo_t siginfo; |
032d82d9 RM |
1350 | int ret; |
1351 | ||
1352 | switch (request) { | |
1353 | case PTRACE_PEEKTEXT: | |
1354 | case PTRACE_PEEKDATA: | |
84d77d3f | 1355 | ret = ptrace_access_vm(child, addr, &word, sizeof(word), |
f307ab6d | 1356 | FOLL_FORCE); |
032d82d9 RM |
1357 | if (ret != sizeof(word)) |
1358 | ret = -EIO; | |
1359 | else | |
1360 | ret = put_user(word, datap); | |
1361 | break; | |
1362 | ||
1363 | case PTRACE_POKETEXT: | |
1364 | case PTRACE_POKEDATA: | |
84d77d3f | 1365 | ret = ptrace_access_vm(child, addr, &data, sizeof(data), |
f307ab6d | 1366 | FOLL_FORCE | FOLL_WRITE); |
032d82d9 RM |
1367 | ret = (ret != sizeof(data) ? -EIO : 0); |
1368 | break; | |
1369 | ||
1370 | case PTRACE_GETEVENTMSG: | |
1371 | ret = put_user((compat_ulong_t) child->ptrace_message, datap); | |
1372 | break; | |
1373 | ||
e16b2781 RM |
1374 | case PTRACE_GETSIGINFO: |
1375 | ret = ptrace_getsiginfo(child, &siginfo); | |
1376 | if (!ret) | |
1377 | ret = copy_siginfo_to_user32( | |
1378 | (struct compat_siginfo __user *) datap, | |
1379 | &siginfo); | |
1380 | break; | |
1381 | ||
1382 | case PTRACE_SETSIGINFO: | |
4cd2e0e7 EB |
1383 | ret = copy_siginfo_from_user32( |
1384 | &siginfo, (struct compat_siginfo __user *) datap); | |
1385 | if (!ret) | |
e16b2781 RM |
1386 | ret = ptrace_setsiginfo(child, &siginfo); |
1387 | break; | |
2225a122 SS |
1388 | #ifdef CONFIG_HAVE_ARCH_TRACEHOOK |
1389 | case PTRACE_GETREGSET: | |
1390 | case PTRACE_SETREGSET: | |
1391 | { | |
1392 | struct iovec kiov; | |
1393 | struct compat_iovec __user *uiov = | |
1394 | (struct compat_iovec __user *) datap; | |
1395 | compat_uptr_t ptr; | |
1396 | compat_size_t len; | |
1397 | ||
96d4f267 | 1398 | if (!access_ok(uiov, sizeof(*uiov))) |
2225a122 SS |
1399 | return -EFAULT; |
1400 | ||
1401 | if (__get_user(ptr, &uiov->iov_base) || | |
1402 | __get_user(len, &uiov->iov_len)) | |
1403 | return -EFAULT; | |
1404 | ||
1405 | kiov.iov_base = compat_ptr(ptr); | |
1406 | kiov.iov_len = len; | |
1407 | ||
1408 | ret = ptrace_regset(child, request, addr, &kiov); | |
1409 | if (!ret) | |
1410 | ret = __put_user(kiov.iov_len, &uiov->iov_len); | |
1411 | break; | |
1412 | } | |
1413 | #endif | |
e16b2781 | 1414 | |
032d82d9 RM |
1415 | default: |
1416 | ret = ptrace_request(child, request, addr, data); | |
1417 | } | |
1418 | ||
1419 | return ret; | |
1420 | } | |
c269f196 | 1421 | |
62a6fa97 HC |
1422 | COMPAT_SYSCALL_DEFINE4(ptrace, compat_long_t, request, compat_long_t, pid, |
1423 | compat_long_t, addr, compat_long_t, data) | |
c269f196 RM |
1424 | { |
1425 | struct task_struct *child; | |
1426 | long ret; | |
1427 | ||
c269f196 RM |
1428 | if (request == PTRACE_TRACEME) { |
1429 | ret = ptrace_traceme(); | |
1430 | goto out; | |
1431 | } | |
1432 | ||
2ee08260 MR |
1433 | child = find_get_task_by_vpid(pid); |
1434 | if (!child) { | |
1435 | ret = -ESRCH; | |
c269f196 RM |
1436 | goto out; |
1437 | } | |
1438 | ||
3544d72a | 1439 | if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) { |
aa9147c9 | 1440 | ret = ptrace_attach(child, request, addr, data); |
c269f196 RM |
1441 | /* |
1442 | * Some architectures need to do book-keeping after | |
1443 | * a ptrace attach. | |
1444 | */ | |
1445 | if (!ret) | |
1446 | arch_ptrace_attach(child); | |
1447 | goto out_put_task_struct; | |
1448 | } | |
1449 | ||
fca26f26 TH |
1450 | ret = ptrace_check_attach(child, request == PTRACE_KILL || |
1451 | request == PTRACE_INTERRUPT); | |
9899d11f | 1452 | if (!ret) { |
c269f196 | 1453 | ret = compat_arch_ptrace(child, request, addr, data); |
9899d11f ON |
1454 | if (ret || request != PTRACE_DETACH) |
1455 | ptrace_unfreeze_traced(child); | |
1456 | } | |
c269f196 RM |
1457 | |
1458 | out_put_task_struct: | |
1459 | put_task_struct(child); | |
1460 | out: | |
c269f196 RM |
1461 | return ret; |
1462 | } | |
96b8936a | 1463 | #endif /* CONFIG_COMPAT */ |