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Commit | Line | Data |
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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 | ||
42966a91 JH |
374 | static int check_ptrace_options(unsigned long data) |
375 | { | |
376 | if (data & ~(unsigned long)PTRACE_O_MASK) | |
377 | return -EINVAL; | |
378 | ||
379 | if (unlikely(data & PTRACE_O_SUSPEND_SECCOMP)) { | |
380 | if (!IS_ENABLED(CONFIG_CHECKPOINT_RESTORE) || | |
381 | !IS_ENABLED(CONFIG_SECCOMP)) | |
382 | return -EINVAL; | |
383 | ||
384 | if (!capable(CAP_SYS_ADMIN)) | |
385 | return -EPERM; | |
386 | ||
387 | if (seccomp_mode(¤t->seccomp) != SECCOMP_MODE_DISABLED || | |
388 | current->ptrace & PT_SUSPEND_SECCOMP) | |
389 | return -EPERM; | |
390 | } | |
391 | return 0; | |
392 | } | |
393 | ||
3544d72a | 394 | static int ptrace_attach(struct task_struct *task, long request, |
aa9147c9 | 395 | unsigned long addr, |
3544d72a | 396 | unsigned long flags) |
1da177e4 | 397 | { |
3544d72a | 398 | bool seize = (request == PTRACE_SEIZE); |
1da177e4 | 399 | int retval; |
f5b40e36 | 400 | |
3544d72a | 401 | retval = -EIO; |
aa9147c9 DV |
402 | if (seize) { |
403 | if (addr != 0) | |
404 | goto out; | |
42966a91 JH |
405 | /* |
406 | * This duplicates the check in check_ptrace_options() because | |
407 | * ptrace_attach() and ptrace_setoptions() have historically | |
408 | * used different error codes for unknown ptrace options. | |
409 | */ | |
aa9147c9 DV |
410 | if (flags & ~(unsigned long)PTRACE_O_MASK) |
411 | goto out; | |
42966a91 JH |
412 | retval = check_ptrace_options(flags); |
413 | if (retval) | |
414 | return retval; | |
aa9147c9 DV |
415 | flags = PT_PTRACED | PT_SEIZED | (flags << PT_OPT_FLAG_SHIFT); |
416 | } else { | |
417 | flags = PT_PTRACED; | |
418 | } | |
3544d72a | 419 | |
a5cb013d AV |
420 | audit_ptrace(task); |
421 | ||
1da177e4 | 422 | retval = -EPERM; |
e8b33b8c | 423 | if (unlikely(task->flags & PF_KTHREAD)) |
b79b7ba9 | 424 | goto out; |
bac0abd6 | 425 | if (same_thread_group(task, current)) |
f5b40e36 LT |
426 | goto out; |
427 | ||
f2f0b00a ON |
428 | /* |
429 | * Protect exec's credential calculations against our interference; | |
86b6c1f3 | 430 | * SUID, SGID and LSM creds get determined differently |
5e751e99 | 431 | * under ptrace. |
d84f4f99 | 432 | */ |
793285fc | 433 | retval = -ERESTARTNOINTR; |
9b1bf12d | 434 | if (mutex_lock_interruptible(&task->signal->cred_guard_mutex)) |
d84f4f99 | 435 | goto out; |
f5b40e36 | 436 | |
4b105cbb | 437 | task_lock(task); |
caaee623 | 438 | retval = __ptrace_may_access(task, PTRACE_MODE_ATTACH_REALCREDS); |
4b105cbb | 439 | task_unlock(task); |
1da177e4 | 440 | if (retval) |
4b105cbb | 441 | goto unlock_creds; |
1da177e4 | 442 | |
4b105cbb | 443 | write_lock_irq(&tasklist_lock); |
b79b7ba9 ON |
444 | retval = -EPERM; |
445 | if (unlikely(task->exit_state)) | |
4b105cbb | 446 | goto unlock_tasklist; |
f2f0b00a | 447 | if (task->ptrace) |
4b105cbb | 448 | goto unlock_tasklist; |
b79b7ba9 | 449 | |
3544d72a | 450 | if (seize) |
aa9147c9 | 451 | flags |= PT_SEIZED; |
aa9147c9 | 452 | task->ptrace = flags; |
1da177e4 | 453 | |
c70d9d80 | 454 | ptrace_link(task, current); |
3544d72a TH |
455 | |
456 | /* SEIZE doesn't trap tracee on attach */ | |
457 | if (!seize) | |
079b22dc | 458 | send_sig_info(SIGSTOP, SEND_SIG_PRIV, task); |
b79b7ba9 | 459 | |
d79fdd6d TH |
460 | spin_lock(&task->sighand->siglock); |
461 | ||
462 | /* | |
73ddff2b | 463 | * If the task is already STOPPED, set JOBCTL_TRAP_STOP and |
d79fdd6d TH |
464 | * TRAPPING, and kick it so that it transits to TRACED. TRAPPING |
465 | * will be cleared if the child completes the transition or any | |
466 | * event which clears the group stop states happens. We'll wait | |
467 | * for the transition to complete before returning from this | |
468 | * function. | |
469 | * | |
470 | * This hides STOPPED -> RUNNING -> TRACED transition from the | |
471 | * attaching thread but a different thread in the same group can | |
472 | * still observe the transient RUNNING state. IOW, if another | |
473 | * thread's WNOHANG wait(2) on the stopped tracee races against | |
474 | * ATTACH, the wait(2) may fail due to the transient RUNNING. | |
475 | * | |
476 | * The following task_is_stopped() test is safe as both transitions | |
477 | * in and out of STOPPED are protected by siglock. | |
478 | */ | |
7dd3db54 | 479 | if (task_is_stopped(task) && |
73ddff2b | 480 | task_set_jobctl_pending(task, JOBCTL_TRAP_STOP | JOBCTL_TRAPPING)) |
910ffdb1 | 481 | signal_wake_up_state(task, __TASK_STOPPED); |
d79fdd6d TH |
482 | |
483 | spin_unlock(&task->sighand->siglock); | |
484 | ||
b79b7ba9 | 485 | retval = 0; |
4b105cbb ON |
486 | unlock_tasklist: |
487 | write_unlock_irq(&tasklist_lock); | |
488 | unlock_creds: | |
9b1bf12d | 489 | mutex_unlock(&task->signal->cred_guard_mutex); |
f5b40e36 | 490 | out: |
f701e5b7 | 491 | if (!retval) { |
7c3b00e0 ON |
492 | /* |
493 | * We do not bother to change retval or clear JOBCTL_TRAPPING | |
494 | * if wait_on_bit() was interrupted by SIGKILL. The tracer will | |
495 | * not return to user-mode, it will exit and clear this bit in | |
496 | * __ptrace_unlink() if it wasn't already cleared by the tracee; | |
497 | * and until then nobody can ptrace this task. | |
498 | */ | |
499 | wait_on_bit(&task->jobctl, JOBCTL_TRAPPING_BIT, TASK_KILLABLE); | |
f701e5b7 VZ |
500 | proc_ptrace_connector(task, PTRACE_ATTACH); |
501 | } | |
502 | ||
1da177e4 LT |
503 | return retval; |
504 | } | |
505 | ||
f2f0b00a ON |
506 | /** |
507 | * ptrace_traceme -- helper for PTRACE_TRACEME | |
508 | * | |
509 | * Performs checks and sets PT_PTRACED. | |
510 | * Should be used by all ptrace implementations for PTRACE_TRACEME. | |
511 | */ | |
e3e89cc5 | 512 | static int ptrace_traceme(void) |
f2f0b00a ON |
513 | { |
514 | int ret = -EPERM; | |
515 | ||
4b105cbb ON |
516 | write_lock_irq(&tasklist_lock); |
517 | /* Are we already being traced? */ | |
f2f0b00a | 518 | if (!current->ptrace) { |
f2f0b00a | 519 | ret = security_ptrace_traceme(current->parent); |
f2f0b00a ON |
520 | /* |
521 | * Check PF_EXITING to ensure ->real_parent has not passed | |
522 | * exit_ptrace(). Otherwise we don't report the error but | |
523 | * pretend ->real_parent untraces us right after return. | |
524 | */ | |
525 | if (!ret && !(current->real_parent->flags & PF_EXITING)) { | |
526 | current->ptrace = PT_PTRACED; | |
c70d9d80 | 527 | ptrace_link(current, current->real_parent); |
f2f0b00a | 528 | } |
f2f0b00a | 529 | } |
4b105cbb ON |
530 | write_unlock_irq(&tasklist_lock); |
531 | ||
f2f0b00a ON |
532 | return ret; |
533 | } | |
534 | ||
39c626ae ON |
535 | /* |
536 | * Called with irqs disabled, returns true if childs should reap themselves. | |
537 | */ | |
538 | static int ignoring_children(struct sighand_struct *sigh) | |
539 | { | |
540 | int ret; | |
541 | spin_lock(&sigh->siglock); | |
542 | ret = (sigh->action[SIGCHLD-1].sa.sa_handler == SIG_IGN) || | |
543 | (sigh->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT); | |
544 | spin_unlock(&sigh->siglock); | |
545 | return ret; | |
546 | } | |
547 | ||
548 | /* | |
549 | * Called with tasklist_lock held for writing. | |
550 | * Unlink a traced task, and clean it up if it was a traced zombie. | |
551 | * Return true if it needs to be reaped with release_task(). | |
552 | * (We can't call release_task() here because we already hold tasklist_lock.) | |
553 | * | |
554 | * If it's a zombie, our attachedness prevented normal parent notification | |
555 | * or self-reaping. Do notification now if it would have happened earlier. | |
556 | * If it should reap itself, return true. | |
557 | * | |
a7f0765e ON |
558 | * If it's our own child, there is no notification to do. But if our normal |
559 | * children self-reap, then this child was prevented by ptrace and we must | |
560 | * reap it now, in that case we must also wake up sub-threads sleeping in | |
561 | * do_wait(). | |
39c626ae ON |
562 | */ |
563 | static bool __ptrace_detach(struct task_struct *tracer, struct task_struct *p) | |
564 | { | |
9843a1e9 ON |
565 | bool dead; |
566 | ||
39c626ae ON |
567 | __ptrace_unlink(p); |
568 | ||
9843a1e9 ON |
569 | if (p->exit_state != EXIT_ZOMBIE) |
570 | return false; | |
571 | ||
572 | dead = !thread_group_leader(p); | |
573 | ||
574 | if (!dead && thread_group_empty(p)) { | |
575 | if (!same_thread_group(p->real_parent, tracer)) | |
576 | dead = do_notify_parent(p, p->exit_signal); | |
577 | else if (ignoring_children(tracer->sighand)) { | |
578 | __wake_up_parent(p, tracer); | |
9843a1e9 | 579 | dead = true; |
39c626ae ON |
580 | } |
581 | } | |
9843a1e9 ON |
582 | /* Mark it as in the process of being reaped. */ |
583 | if (dead) | |
584 | p->exit_state = EXIT_DEAD; | |
585 | return dead; | |
39c626ae ON |
586 | } |
587 | ||
e3e89cc5 | 588 | static int ptrace_detach(struct task_struct *child, unsigned int data) |
1da177e4 | 589 | { |
7ed20e1a | 590 | if (!valid_signal(data)) |
5ecfbae0 | 591 | return -EIO; |
1da177e4 LT |
592 | |
593 | /* Architecture-specific hardware disable .. */ | |
594 | ptrace_disable(child); | |
595 | ||
95c3eb76 | 596 | write_lock_irq(&tasklist_lock); |
39c626ae | 597 | /* |
64a4096c ON |
598 | * We rely on ptrace_freeze_traced(). It can't be killed and |
599 | * untraced by another thread, it can't be a zombie. | |
39c626ae | 600 | */ |
64a4096c ON |
601 | WARN_ON(!child->ptrace || child->exit_state); |
602 | /* | |
603 | * tasklist_lock avoids the race with wait_task_stopped(), see | |
604 | * the comment in ptrace_resume(). | |
605 | */ | |
606 | child->exit_code = data; | |
607 | __ptrace_detach(current, child); | |
1da177e4 LT |
608 | write_unlock_irq(&tasklist_lock); |
609 | ||
f701e5b7 | 610 | proc_ptrace_connector(child, PTRACE_DETACH); |
4576145c | 611 | |
1da177e4 LT |
612 | return 0; |
613 | } | |
614 | ||
39c626ae | 615 | /* |
c7e49c14 | 616 | * Detach all tasks we were using ptrace on. Called with tasklist held |
7c8bd232 | 617 | * for writing. |
39c626ae | 618 | */ |
7c8bd232 | 619 | void exit_ptrace(struct task_struct *tracer, struct list_head *dead) |
39c626ae ON |
620 | { |
621 | struct task_struct *p, *n; | |
c7e49c14 | 622 | |
39c626ae | 623 | list_for_each_entry_safe(p, n, &tracer->ptraced, ptrace_entry) { |
992fb6e1 | 624 | if (unlikely(p->ptrace & PT_EXITKILL)) |
079b22dc | 625 | send_sig_info(SIGKILL, SEND_SIG_PRIV, p); |
992fb6e1 | 626 | |
39c626ae | 627 | if (__ptrace_detach(tracer, p)) |
7c8bd232 | 628 | list_add(&p->ptrace_entry, dead); |
39c626ae ON |
629 | } |
630 | } | |
631 | ||
1da177e4 LT |
632 | int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len) |
633 | { | |
634 | int copied = 0; | |
635 | ||
636 | while (len > 0) { | |
637 | char buf[128]; | |
638 | int this_len, retval; | |
639 | ||
640 | this_len = (len > sizeof(buf)) ? sizeof(buf) : len; | |
84d77d3f EB |
641 | retval = ptrace_access_vm(tsk, src, buf, this_len, FOLL_FORCE); |
642 | ||
1da177e4 LT |
643 | if (!retval) { |
644 | if (copied) | |
645 | break; | |
646 | return -EIO; | |
647 | } | |
648 | if (copy_to_user(dst, buf, retval)) | |
649 | return -EFAULT; | |
650 | copied += retval; | |
651 | src += retval; | |
652 | dst += retval; | |
3a709703 | 653 | len -= retval; |
1da177e4 LT |
654 | } |
655 | return copied; | |
656 | } | |
657 | ||
658 | int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len) | |
659 | { | |
660 | int copied = 0; | |
661 | ||
662 | while (len > 0) { | |
663 | char buf[128]; | |
664 | int this_len, retval; | |
665 | ||
666 | this_len = (len > sizeof(buf)) ? sizeof(buf) : len; | |
667 | if (copy_from_user(buf, src, this_len)) | |
668 | return -EFAULT; | |
84d77d3f | 669 | retval = ptrace_access_vm(tsk, dst, buf, this_len, |
f307ab6d | 670 | FOLL_FORCE | FOLL_WRITE); |
1da177e4 LT |
671 | if (!retval) { |
672 | if (copied) | |
673 | break; | |
674 | return -EIO; | |
675 | } | |
676 | copied += retval; | |
677 | src += retval; | |
678 | dst += retval; | |
3a709703 | 679 | len -= retval; |
1da177e4 LT |
680 | } |
681 | return copied; | |
682 | } | |
683 | ||
4abf9869 | 684 | static int ptrace_setoptions(struct task_struct *child, unsigned long data) |
1da177e4 | 685 | { |
86b6c1f3 | 686 | unsigned flags; |
42966a91 | 687 | int ret; |
86b6c1f3 | 688 | |
42966a91 JH |
689 | ret = check_ptrace_options(data); |
690 | if (ret) | |
691 | return ret; | |
13c4a901 | 692 | |
86b6c1f3 DV |
693 | /* Avoid intermediate state when all opts are cleared */ |
694 | flags = child->ptrace; | |
695 | flags &= ~(PTRACE_O_MASK << PT_OPT_FLAG_SHIFT); | |
696 | flags |= (data << PT_OPT_FLAG_SHIFT); | |
697 | child->ptrace = flags; | |
1da177e4 | 698 | |
8c5cf9e5 | 699 | return 0; |
1da177e4 LT |
700 | } |
701 | ||
ae7795bc | 702 | static int ptrace_getsiginfo(struct task_struct *child, kernel_siginfo_t *info) |
1da177e4 | 703 | { |
e4961254 | 704 | unsigned long flags; |
1da177e4 LT |
705 | int error = -ESRCH; |
706 | ||
e4961254 | 707 | if (lock_task_sighand(child, &flags)) { |
1da177e4 | 708 | error = -EINVAL; |
1da177e4 | 709 | if (likely(child->last_siginfo != NULL)) { |
0752d7bf | 710 | copy_siginfo(info, child->last_siginfo); |
1da177e4 LT |
711 | error = 0; |
712 | } | |
e4961254 | 713 | unlock_task_sighand(child, &flags); |
1da177e4 | 714 | } |
1da177e4 LT |
715 | return error; |
716 | } | |
717 | ||
ae7795bc | 718 | static int ptrace_setsiginfo(struct task_struct *child, const kernel_siginfo_t *info) |
1da177e4 | 719 | { |
e4961254 | 720 | unsigned long flags; |
1da177e4 LT |
721 | int error = -ESRCH; |
722 | ||
e4961254 | 723 | if (lock_task_sighand(child, &flags)) { |
1da177e4 | 724 | error = -EINVAL; |
1da177e4 | 725 | if (likely(child->last_siginfo != NULL)) { |
0752d7bf | 726 | copy_siginfo(child->last_siginfo, info); |
1da177e4 LT |
727 | error = 0; |
728 | } | |
e4961254 | 729 | unlock_task_sighand(child, &flags); |
1da177e4 | 730 | } |
1da177e4 LT |
731 | return error; |
732 | } | |
733 | ||
84c751bd AV |
734 | static int ptrace_peek_siginfo(struct task_struct *child, |
735 | unsigned long addr, | |
736 | unsigned long data) | |
737 | { | |
738 | struct ptrace_peeksiginfo_args arg; | |
739 | struct sigpending *pending; | |
740 | struct sigqueue *q; | |
741 | int ret, i; | |
742 | ||
743 | ret = copy_from_user(&arg, (void __user *) addr, | |
744 | sizeof(struct ptrace_peeksiginfo_args)); | |
745 | if (ret) | |
746 | return -EFAULT; | |
747 | ||
748 | if (arg.flags & ~PTRACE_PEEKSIGINFO_SHARED) | |
749 | return -EINVAL; /* unknown flags */ | |
750 | ||
751 | if (arg.nr < 0) | |
752 | return -EINVAL; | |
753 | ||
f6e2aa91 EB |
754 | /* Ensure arg.off fits in an unsigned long */ |
755 | if (arg.off > ULONG_MAX) | |
756 | return 0; | |
757 | ||
84c751bd AV |
758 | if (arg.flags & PTRACE_PEEKSIGINFO_SHARED) |
759 | pending = &child->signal->shared_pending; | |
760 | else | |
761 | pending = &child->pending; | |
762 | ||
763 | for (i = 0; i < arg.nr; ) { | |
ae7795bc | 764 | kernel_siginfo_t info; |
f6e2aa91 EB |
765 | unsigned long off = arg.off + i; |
766 | bool found = false; | |
84c751bd AV |
767 | |
768 | spin_lock_irq(&child->sighand->siglock); | |
769 | list_for_each_entry(q, &pending->list, list) { | |
770 | if (!off--) { | |
f6e2aa91 | 771 | found = true; |
84c751bd AV |
772 | copy_siginfo(&info, &q->info); |
773 | break; | |
774 | } | |
775 | } | |
776 | spin_unlock_irq(&child->sighand->siglock); | |
777 | ||
f6e2aa91 | 778 | if (!found) /* beyond the end of the list */ |
84c751bd AV |
779 | break; |
780 | ||
781 | #ifdef CONFIG_COMPAT | |
5c465217 | 782 | if (unlikely(in_compat_syscall())) { |
84c751bd AV |
783 | compat_siginfo_t __user *uinfo = compat_ptr(data); |
784 | ||
cc731525 | 785 | if (copy_siginfo_to_user32(uinfo, &info)) { |
706b23bd MD |
786 | ret = -EFAULT; |
787 | break; | |
788 | } | |
789 | ||
84c751bd AV |
790 | } else |
791 | #endif | |
792 | { | |
793 | siginfo_t __user *uinfo = (siginfo_t __user *) data; | |
794 | ||
cc731525 | 795 | if (copy_siginfo_to_user(uinfo, &info)) { |
706b23bd MD |
796 | ret = -EFAULT; |
797 | break; | |
798 | } | |
84c751bd AV |
799 | } |
800 | ||
801 | data += sizeof(siginfo_t); | |
802 | i++; | |
803 | ||
804 | if (signal_pending(current)) | |
805 | break; | |
806 | ||
807 | cond_resched(); | |
808 | } | |
809 | ||
810 | if (i > 0) | |
811 | return i; | |
812 | ||
813 | return ret; | |
814 | } | |
36df29d7 | 815 | |
90f093fa PF |
816 | #ifdef CONFIG_RSEQ |
817 | static long ptrace_get_rseq_configuration(struct task_struct *task, | |
818 | unsigned long size, void __user *data) | |
819 | { | |
820 | struct ptrace_rseq_configuration conf = { | |
821 | .rseq_abi_pointer = (u64)(uintptr_t)task->rseq, | |
822 | .rseq_abi_size = sizeof(*task->rseq), | |
823 | .signature = task->rseq_sig, | |
824 | .flags = 0, | |
825 | }; | |
826 | ||
827 | size = min_t(unsigned long, size, sizeof(conf)); | |
828 | if (copy_to_user(data, &conf, size)) | |
829 | return -EFAULT; | |
830 | return sizeof(conf); | |
831 | } | |
832 | #endif | |
833 | ||
36df29d7 RM |
834 | #ifdef PTRACE_SINGLESTEP |
835 | #define is_singlestep(request) ((request) == PTRACE_SINGLESTEP) | |
836 | #else | |
837 | #define is_singlestep(request) 0 | |
838 | #endif | |
839 | ||
5b88abbf RM |
840 | #ifdef PTRACE_SINGLEBLOCK |
841 | #define is_singleblock(request) ((request) == PTRACE_SINGLEBLOCK) | |
842 | #else | |
843 | #define is_singleblock(request) 0 | |
844 | #endif | |
845 | ||
36df29d7 RM |
846 | #ifdef PTRACE_SYSEMU |
847 | #define is_sysemu_singlestep(request) ((request) == PTRACE_SYSEMU_SINGLESTEP) | |
848 | #else | |
849 | #define is_sysemu_singlestep(request) 0 | |
850 | #endif | |
851 | ||
4abf9869 NK |
852 | static int ptrace_resume(struct task_struct *child, long request, |
853 | unsigned long data) | |
36df29d7 | 854 | { |
b72c1869 ON |
855 | bool need_siglock; |
856 | ||
36df29d7 RM |
857 | if (!valid_signal(data)) |
858 | return -EIO; | |
859 | ||
860 | if (request == PTRACE_SYSCALL) | |
64c19ba2 | 861 | set_task_syscall_work(child, SYSCALL_TRACE); |
36df29d7 | 862 | else |
64c19ba2 | 863 | clear_task_syscall_work(child, SYSCALL_TRACE); |
36df29d7 | 864 | |
64eb35f7 | 865 | #if defined(CONFIG_GENERIC_ENTRY) || defined(TIF_SYSCALL_EMU) |
36df29d7 | 866 | if (request == PTRACE_SYSEMU || request == PTRACE_SYSEMU_SINGLESTEP) |
64eb35f7 | 867 | set_task_syscall_work(child, SYSCALL_EMU); |
36df29d7 | 868 | else |
64eb35f7 | 869 | clear_task_syscall_work(child, SYSCALL_EMU); |
36df29d7 RM |
870 | #endif |
871 | ||
5b88abbf RM |
872 | if (is_singleblock(request)) { |
873 | if (unlikely(!arch_has_block_step())) | |
874 | return -EIO; | |
875 | user_enable_block_step(child); | |
876 | } else if (is_singlestep(request) || is_sysemu_singlestep(request)) { | |
36df29d7 RM |
877 | if (unlikely(!arch_has_single_step())) |
878 | return -EIO; | |
879 | user_enable_single_step(child); | |
3a709703 | 880 | } else { |
36df29d7 | 881 | user_disable_single_step(child); |
3a709703 | 882 | } |
36df29d7 | 883 | |
b72c1869 ON |
884 | /* |
885 | * Change ->exit_code and ->state under siglock to avoid the race | |
886 | * with wait_task_stopped() in between; a non-zero ->exit_code will | |
887 | * wrongly look like another report from tracee. | |
888 | * | |
889 | * Note that we need siglock even if ->exit_code == data and/or this | |
890 | * status was not reported yet, the new status must not be cleared by | |
891 | * wait_task_stopped() after resume. | |
892 | * | |
893 | * If data == 0 we do not care if wait_task_stopped() reports the old | |
894 | * status and clears the code too; this can't race with the tracee, it | |
895 | * takes siglock after resume. | |
896 | */ | |
897 | need_siglock = data && !thread_group_empty(current); | |
898 | if (need_siglock) | |
899 | spin_lock_irq(&child->sighand->siglock); | |
36df29d7 | 900 | child->exit_code = data; |
0666fb51 | 901 | wake_up_state(child, __TASK_TRACED); |
b72c1869 ON |
902 | if (need_siglock) |
903 | spin_unlock_irq(&child->sighand->siglock); | |
36df29d7 RM |
904 | |
905 | return 0; | |
906 | } | |
907 | ||
2225a122 SS |
908 | #ifdef CONFIG_HAVE_ARCH_TRACEHOOK |
909 | ||
910 | static const struct user_regset * | |
911 | find_regset(const struct user_regset_view *view, unsigned int type) | |
912 | { | |
913 | const struct user_regset *regset; | |
914 | int n; | |
915 | ||
916 | for (n = 0; n < view->n; ++n) { | |
917 | regset = view->regsets + n; | |
918 | if (regset->core_note_type == type) | |
919 | return regset; | |
920 | } | |
921 | ||
922 | return NULL; | |
923 | } | |
924 | ||
925 | static int ptrace_regset(struct task_struct *task, int req, unsigned int type, | |
926 | struct iovec *kiov) | |
927 | { | |
928 | const struct user_regset_view *view = task_user_regset_view(task); | |
929 | const struct user_regset *regset = find_regset(view, type); | |
930 | int regset_no; | |
931 | ||
932 | if (!regset || (kiov->iov_len % regset->size) != 0) | |
c6a0dd7e | 933 | return -EINVAL; |
2225a122 SS |
934 | |
935 | regset_no = regset - view->regsets; | |
936 | kiov->iov_len = min(kiov->iov_len, | |
937 | (__kernel_size_t) (regset->n * regset->size)); | |
938 | ||
939 | if (req == PTRACE_GETREGSET) | |
940 | return copy_regset_to_user(task, view, regset_no, 0, | |
941 | kiov->iov_len, kiov->iov_base); | |
942 | else | |
943 | return copy_regset_from_user(task, view, regset_no, 0, | |
944 | kiov->iov_len, kiov->iov_base); | |
945 | } | |
946 | ||
e8440c14 JS |
947 | /* |
948 | * This is declared in linux/regset.h and defined in machine-dependent | |
949 | * code. We put the export here, near the primary machine-neutral use, | |
950 | * to ensure no machine forgets it. | |
951 | */ | |
952 | EXPORT_SYMBOL_GPL(task_user_regset_view); | |
201766a2 EK |
953 | |
954 | static unsigned long | |
955 | ptrace_get_syscall_info_entry(struct task_struct *child, struct pt_regs *regs, | |
956 | struct ptrace_syscall_info *info) | |
957 | { | |
958 | unsigned long args[ARRAY_SIZE(info->entry.args)]; | |
959 | int i; | |
960 | ||
961 | info->op = PTRACE_SYSCALL_INFO_ENTRY; | |
962 | info->entry.nr = syscall_get_nr(child, regs); | |
963 | syscall_get_arguments(child, regs, args); | |
964 | for (i = 0; i < ARRAY_SIZE(args); i++) | |
965 | info->entry.args[i] = args[i]; | |
966 | ||
967 | /* args is the last field in struct ptrace_syscall_info.entry */ | |
968 | return offsetofend(struct ptrace_syscall_info, entry.args); | |
969 | } | |
970 | ||
971 | static unsigned long | |
972 | ptrace_get_syscall_info_seccomp(struct task_struct *child, struct pt_regs *regs, | |
973 | struct ptrace_syscall_info *info) | |
974 | { | |
975 | /* | |
976 | * As struct ptrace_syscall_info.entry is currently a subset | |
977 | * of struct ptrace_syscall_info.seccomp, it makes sense to | |
978 | * initialize that subset using ptrace_get_syscall_info_entry(). | |
979 | * This can be reconsidered in the future if these structures | |
980 | * diverge significantly enough. | |
981 | */ | |
982 | ptrace_get_syscall_info_entry(child, regs, info); | |
983 | info->op = PTRACE_SYSCALL_INFO_SECCOMP; | |
984 | info->seccomp.ret_data = child->ptrace_message; | |
985 | ||
986 | /* ret_data is the last field in struct ptrace_syscall_info.seccomp */ | |
987 | return offsetofend(struct ptrace_syscall_info, seccomp.ret_data); | |
988 | } | |
989 | ||
990 | static unsigned long | |
991 | ptrace_get_syscall_info_exit(struct task_struct *child, struct pt_regs *regs, | |
992 | struct ptrace_syscall_info *info) | |
993 | { | |
994 | info->op = PTRACE_SYSCALL_INFO_EXIT; | |
995 | info->exit.rval = syscall_get_error(child, regs); | |
996 | info->exit.is_error = !!info->exit.rval; | |
997 | if (!info->exit.is_error) | |
998 | info->exit.rval = syscall_get_return_value(child, regs); | |
999 | ||
1000 | /* is_error is the last field in struct ptrace_syscall_info.exit */ | |
1001 | return offsetofend(struct ptrace_syscall_info, exit.is_error); | |
1002 | } | |
1003 | ||
1004 | static int | |
1005 | ptrace_get_syscall_info(struct task_struct *child, unsigned long user_size, | |
1006 | void __user *datavp) | |
1007 | { | |
1008 | struct pt_regs *regs = task_pt_regs(child); | |
1009 | struct ptrace_syscall_info info = { | |
1010 | .op = PTRACE_SYSCALL_INFO_NONE, | |
1011 | .arch = syscall_get_arch(child), | |
1012 | .instruction_pointer = instruction_pointer(regs), | |
1013 | .stack_pointer = user_stack_pointer(regs), | |
1014 | }; | |
1015 | unsigned long actual_size = offsetof(struct ptrace_syscall_info, entry); | |
1016 | unsigned long write_size; | |
1017 | ||
1018 | /* | |
1019 | * This does not need lock_task_sighand() to access | |
1020 | * child->last_siginfo because ptrace_freeze_traced() | |
1021 | * called earlier by ptrace_check_attach() ensures that | |
1022 | * the tracee cannot go away and clear its last_siginfo. | |
1023 | */ | |
1024 | switch (child->last_siginfo ? child->last_siginfo->si_code : 0) { | |
1025 | case SIGTRAP | 0x80: | |
1026 | switch (child->ptrace_message) { | |
1027 | case PTRACE_EVENTMSG_SYSCALL_ENTRY: | |
1028 | actual_size = ptrace_get_syscall_info_entry(child, regs, | |
1029 | &info); | |
1030 | break; | |
1031 | case PTRACE_EVENTMSG_SYSCALL_EXIT: | |
1032 | actual_size = ptrace_get_syscall_info_exit(child, regs, | |
1033 | &info); | |
1034 | break; | |
1035 | } | |
1036 | break; | |
1037 | case SIGTRAP | (PTRACE_EVENT_SECCOMP << 8): | |
1038 | actual_size = ptrace_get_syscall_info_seccomp(child, regs, | |
1039 | &info); | |
1040 | break; | |
1041 | } | |
1042 | ||
1043 | write_size = min(actual_size, user_size); | |
1044 | return copy_to_user(datavp, &info, write_size) ? -EFAULT : actual_size; | |
1045 | } | |
1046 | #endif /* CONFIG_HAVE_ARCH_TRACEHOOK */ | |
2225a122 | 1047 | |
1da177e4 | 1048 | int ptrace_request(struct task_struct *child, long request, |
4abf9869 | 1049 | unsigned long addr, unsigned long data) |
1da177e4 | 1050 | { |
fca26f26 | 1051 | bool seized = child->ptrace & PT_SEIZED; |
1da177e4 | 1052 | int ret = -EIO; |
ae7795bc | 1053 | kernel_siginfo_t siginfo, *si; |
9fed81dc NK |
1054 | void __user *datavp = (void __user *) data; |
1055 | unsigned long __user *datalp = datavp; | |
fca26f26 | 1056 | unsigned long flags; |
1da177e4 LT |
1057 | |
1058 | switch (request) { | |
16c3e389 RM |
1059 | case PTRACE_PEEKTEXT: |
1060 | case PTRACE_PEEKDATA: | |
1061 | return generic_ptrace_peekdata(child, addr, data); | |
1062 | case PTRACE_POKETEXT: | |
1063 | case PTRACE_POKEDATA: | |
1064 | return generic_ptrace_pokedata(child, addr, data); | |
1065 | ||
1da177e4 LT |
1066 | #ifdef PTRACE_OLDSETOPTIONS |
1067 | case PTRACE_OLDSETOPTIONS: | |
1068 | #endif | |
1069 | case PTRACE_SETOPTIONS: | |
1070 | ret = ptrace_setoptions(child, data); | |
1071 | break; | |
1072 | case PTRACE_GETEVENTMSG: | |
9fed81dc | 1073 | ret = put_user(child->ptrace_message, datalp); |
1da177e4 | 1074 | break; |
e16b2781 | 1075 | |
84c751bd AV |
1076 | case PTRACE_PEEKSIGINFO: |
1077 | ret = ptrace_peek_siginfo(child, addr, data); | |
1078 | break; | |
1079 | ||
1da177e4 | 1080 | case PTRACE_GETSIGINFO: |
e16b2781 RM |
1081 | ret = ptrace_getsiginfo(child, &siginfo); |
1082 | if (!ret) | |
9fed81dc | 1083 | ret = copy_siginfo_to_user(datavp, &siginfo); |
1da177e4 | 1084 | break; |
e16b2781 | 1085 | |
1da177e4 | 1086 | case PTRACE_SETSIGINFO: |
4cd2e0e7 EB |
1087 | ret = copy_siginfo_from_user(&siginfo, datavp); |
1088 | if (!ret) | |
e16b2781 | 1089 | ret = ptrace_setsiginfo(child, &siginfo); |
1da177e4 | 1090 | break; |
e16b2781 | 1091 | |
fcfc2aa0 AV |
1092 | case PTRACE_GETSIGMASK: { |
1093 | sigset_t *mask; | |
1094 | ||
29000cae AV |
1095 | if (addr != sizeof(sigset_t)) { |
1096 | ret = -EINVAL; | |
1097 | break; | |
1098 | } | |
1099 | ||
fcfc2aa0 AV |
1100 | if (test_tsk_restore_sigmask(child)) |
1101 | mask = &child->saved_sigmask; | |
1102 | else | |
1103 | mask = &child->blocked; | |
1104 | ||
1105 | if (copy_to_user(datavp, mask, sizeof(sigset_t))) | |
29000cae AV |
1106 | ret = -EFAULT; |
1107 | else | |
1108 | ret = 0; | |
1109 | ||
1110 | break; | |
fcfc2aa0 | 1111 | } |
29000cae AV |
1112 | |
1113 | case PTRACE_SETSIGMASK: { | |
1114 | sigset_t new_set; | |
1115 | ||
1116 | if (addr != sizeof(sigset_t)) { | |
1117 | ret = -EINVAL; | |
1118 | break; | |
1119 | } | |
1120 | ||
1121 | if (copy_from_user(&new_set, datavp, sizeof(sigset_t))) { | |
1122 | ret = -EFAULT; | |
1123 | break; | |
1124 | } | |
1125 | ||
1126 | sigdelsetmask(&new_set, sigmask(SIGKILL)|sigmask(SIGSTOP)); | |
1127 | ||
1128 | /* | |
1129 | * Every thread does recalc_sigpending() after resume, so | |
1130 | * retarget_shared_pending() and recalc_sigpending() are not | |
1131 | * called here. | |
1132 | */ | |
1133 | spin_lock_irq(&child->sighand->siglock); | |
1134 | child->blocked = new_set; | |
1135 | spin_unlock_irq(&child->sighand->siglock); | |
1136 | ||
fcfc2aa0 AV |
1137 | clear_tsk_restore_sigmask(child); |
1138 | ||
29000cae AV |
1139 | ret = 0; |
1140 | break; | |
1141 | } | |
1142 | ||
fca26f26 TH |
1143 | case PTRACE_INTERRUPT: |
1144 | /* | |
1145 | * Stop tracee without any side-effect on signal or job | |
1146 | * control. At least one trap is guaranteed to happen | |
1147 | * after this request. If @child is already trapped, the | |
1148 | * current trap is not disturbed and another trap will | |
1149 | * happen after the current trap is ended with PTRACE_CONT. | |
1150 | * | |
1151 | * The actual trap might not be PTRACE_EVENT_STOP trap but | |
1152 | * the pending condition is cleared regardless. | |
1153 | */ | |
1154 | if (unlikely(!seized || !lock_task_sighand(child, &flags))) | |
1155 | break; | |
1156 | ||
544b2c91 TH |
1157 | /* |
1158 | * INTERRUPT doesn't disturb existing trap sans one | |
1159 | * exception. If ptracer issued LISTEN for the current | |
1160 | * STOP, this INTERRUPT should clear LISTEN and re-trap | |
1161 | * tracee into STOP. | |
1162 | */ | |
fca26f26 | 1163 | if (likely(task_set_jobctl_pending(child, JOBCTL_TRAP_STOP))) |
910ffdb1 | 1164 | ptrace_signal_wake_up(child, child->jobctl & JOBCTL_LISTENING); |
544b2c91 TH |
1165 | |
1166 | unlock_task_sighand(child, &flags); | |
1167 | ret = 0; | |
1168 | break; | |
1169 | ||
1170 | case PTRACE_LISTEN: | |
1171 | /* | |
1172 | * Listen for events. Tracee must be in STOP. It's not | |
1173 | * resumed per-se but is not considered to be in TRACED by | |
1174 | * wait(2) or ptrace(2). If an async event (e.g. group | |
1175 | * stop state change) happens, tracee will enter STOP trap | |
1176 | * again. Alternatively, ptracer can issue INTERRUPT to | |
1177 | * finish listening and re-trap tracee into STOP. | |
1178 | */ | |
1179 | if (unlikely(!seized || !lock_task_sighand(child, &flags))) | |
1180 | break; | |
1181 | ||
1182 | si = child->last_siginfo; | |
f9d81f61 ON |
1183 | if (likely(si && (si->si_code >> 8) == PTRACE_EVENT_STOP)) { |
1184 | child->jobctl |= JOBCTL_LISTENING; | |
1185 | /* | |
1186 | * If NOTIFY is set, it means event happened between | |
1187 | * start of this trap and now. Trigger re-trap. | |
1188 | */ | |
1189 | if (child->jobctl & JOBCTL_TRAP_NOTIFY) | |
910ffdb1 | 1190 | ptrace_signal_wake_up(child, true); |
f9d81f61 ON |
1191 | ret = 0; |
1192 | } | |
fca26f26 | 1193 | unlock_task_sighand(child, &flags); |
fca26f26 TH |
1194 | break; |
1195 | ||
1bcf5482 AD |
1196 | case PTRACE_DETACH: /* detach a process that was attached. */ |
1197 | ret = ptrace_detach(child, data); | |
1198 | break; | |
36df29d7 | 1199 | |
9c1a1259 MF |
1200 | #ifdef CONFIG_BINFMT_ELF_FDPIC |
1201 | case PTRACE_GETFDPIC: { | |
e0129ef9 | 1202 | struct mm_struct *mm = get_task_mm(child); |
9c1a1259 MF |
1203 | unsigned long tmp = 0; |
1204 | ||
e0129ef9 ON |
1205 | ret = -ESRCH; |
1206 | if (!mm) | |
1207 | break; | |
1208 | ||
9c1a1259 MF |
1209 | switch (addr) { |
1210 | case PTRACE_GETFDPIC_EXEC: | |
e0129ef9 | 1211 | tmp = mm->context.exec_fdpic_loadmap; |
9c1a1259 MF |
1212 | break; |
1213 | case PTRACE_GETFDPIC_INTERP: | |
e0129ef9 | 1214 | tmp = mm->context.interp_fdpic_loadmap; |
9c1a1259 MF |
1215 | break; |
1216 | default: | |
1217 | break; | |
1218 | } | |
e0129ef9 | 1219 | mmput(mm); |
9c1a1259 | 1220 | |
9fed81dc | 1221 | ret = put_user(tmp, datalp); |
9c1a1259 MF |
1222 | break; |
1223 | } | |
1224 | #endif | |
1225 | ||
36df29d7 RM |
1226 | #ifdef PTRACE_SINGLESTEP |
1227 | case PTRACE_SINGLESTEP: | |
1228 | #endif | |
5b88abbf RM |
1229 | #ifdef PTRACE_SINGLEBLOCK |
1230 | case PTRACE_SINGLEBLOCK: | |
1231 | #endif | |
36df29d7 RM |
1232 | #ifdef PTRACE_SYSEMU |
1233 | case PTRACE_SYSEMU: | |
1234 | case PTRACE_SYSEMU_SINGLESTEP: | |
1235 | #endif | |
1236 | case PTRACE_SYSCALL: | |
1237 | case PTRACE_CONT: | |
1238 | return ptrace_resume(child, request, data); | |
1239 | ||
1240 | case PTRACE_KILL: | |
1241 | if (child->exit_state) /* already dead */ | |
1242 | return 0; | |
1243 | return ptrace_resume(child, request, SIGKILL); | |
1244 | ||
2225a122 SS |
1245 | #ifdef CONFIG_HAVE_ARCH_TRACEHOOK |
1246 | case PTRACE_GETREGSET: | |
29000cae | 1247 | case PTRACE_SETREGSET: { |
2225a122 | 1248 | struct iovec kiov; |
9fed81dc | 1249 | struct iovec __user *uiov = datavp; |
2225a122 | 1250 | |
96d4f267 | 1251 | if (!access_ok(uiov, sizeof(*uiov))) |
2225a122 SS |
1252 | return -EFAULT; |
1253 | ||
1254 | if (__get_user(kiov.iov_base, &uiov->iov_base) || | |
1255 | __get_user(kiov.iov_len, &uiov->iov_len)) | |
1256 | return -EFAULT; | |
1257 | ||
1258 | ret = ptrace_regset(child, request, addr, &kiov); | |
1259 | if (!ret) | |
1260 | ret = __put_user(kiov.iov_len, &uiov->iov_len); | |
1261 | break; | |
1262 | } | |
201766a2 EK |
1263 | |
1264 | case PTRACE_GET_SYSCALL_INFO: | |
1265 | ret = ptrace_get_syscall_info(child, addr, datavp); | |
1266 | break; | |
2225a122 | 1267 | #endif |
f8e529ed TA |
1268 | |
1269 | case PTRACE_SECCOMP_GET_FILTER: | |
1270 | ret = seccomp_get_filter(child, addr, datavp); | |
1271 | break; | |
1272 | ||
26500475 TA |
1273 | case PTRACE_SECCOMP_GET_METADATA: |
1274 | ret = seccomp_get_metadata(child, addr, datavp); | |
1275 | break; | |
1276 | ||
90f093fa PF |
1277 | #ifdef CONFIG_RSEQ |
1278 | case PTRACE_GET_RSEQ_CONFIGURATION: | |
1279 | ret = ptrace_get_rseq_configuration(child, addr, datavp); | |
1280 | break; | |
1281 | #endif | |
1282 | ||
1da177e4 LT |
1283 | default: |
1284 | break; | |
1285 | } | |
1286 | ||
1287 | return ret; | |
1288 | } | |
481bed45 | 1289 | |
0ac15559 CH |
1290 | #ifndef arch_ptrace_attach |
1291 | #define arch_ptrace_attach(child) do { } while (0) | |
1292 | #endif | |
1293 | ||
4abf9869 NK |
1294 | SYSCALL_DEFINE4(ptrace, long, request, long, pid, unsigned long, addr, |
1295 | unsigned long, data) | |
481bed45 CH |
1296 | { |
1297 | struct task_struct *child; | |
1298 | long ret; | |
1299 | ||
6b9c7ed8 CH |
1300 | if (request == PTRACE_TRACEME) { |
1301 | ret = ptrace_traceme(); | |
6ea6dd93 HS |
1302 | if (!ret) |
1303 | arch_ptrace_attach(current); | |
481bed45 | 1304 | goto out; |
6b9c7ed8 CH |
1305 | } |
1306 | ||
2ee08260 MR |
1307 | child = find_get_task_by_vpid(pid); |
1308 | if (!child) { | |
1309 | ret = -ESRCH; | |
6b9c7ed8 CH |
1310 | goto out; |
1311 | } | |
481bed45 | 1312 | |
3544d72a | 1313 | if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) { |
aa9147c9 | 1314 | ret = ptrace_attach(child, request, addr, data); |
0ac15559 CH |
1315 | /* |
1316 | * Some architectures need to do book-keeping after | |
1317 | * a ptrace attach. | |
1318 | */ | |
1319 | if (!ret) | |
1320 | arch_ptrace_attach(child); | |
005f18df | 1321 | goto out_put_task_struct; |
481bed45 CH |
1322 | } |
1323 | ||
fca26f26 TH |
1324 | ret = ptrace_check_attach(child, request == PTRACE_KILL || |
1325 | request == PTRACE_INTERRUPT); | |
481bed45 CH |
1326 | if (ret < 0) |
1327 | goto out_put_task_struct; | |
1328 | ||
1329 | ret = arch_ptrace(child, request, addr, data); | |
9899d11f ON |
1330 | if (ret || request != PTRACE_DETACH) |
1331 | ptrace_unfreeze_traced(child); | |
481bed45 CH |
1332 | |
1333 | out_put_task_struct: | |
1334 | put_task_struct(child); | |
1335 | out: | |
481bed45 CH |
1336 | return ret; |
1337 | } | |
76647323 | 1338 | |
4abf9869 NK |
1339 | int generic_ptrace_peekdata(struct task_struct *tsk, unsigned long addr, |
1340 | unsigned long data) | |
76647323 AD |
1341 | { |
1342 | unsigned long tmp; | |
1343 | int copied; | |
1344 | ||
84d77d3f | 1345 | copied = ptrace_access_vm(tsk, addr, &tmp, sizeof(tmp), FOLL_FORCE); |
76647323 AD |
1346 | if (copied != sizeof(tmp)) |
1347 | return -EIO; | |
1348 | return put_user(tmp, (unsigned long __user *)data); | |
1349 | } | |
f284ce72 | 1350 | |
4abf9869 NK |
1351 | int generic_ptrace_pokedata(struct task_struct *tsk, unsigned long addr, |
1352 | unsigned long data) | |
f284ce72 AD |
1353 | { |
1354 | int copied; | |
1355 | ||
84d77d3f | 1356 | copied = ptrace_access_vm(tsk, addr, &data, sizeof(data), |
f307ab6d | 1357 | FOLL_FORCE | FOLL_WRITE); |
f284ce72 AD |
1358 | return (copied == sizeof(data)) ? 0 : -EIO; |
1359 | } | |
032d82d9 | 1360 | |
96b8936a | 1361 | #if defined CONFIG_COMPAT |
032d82d9 RM |
1362 | |
1363 | int compat_ptrace_request(struct task_struct *child, compat_long_t request, | |
1364 | compat_ulong_t addr, compat_ulong_t data) | |
1365 | { | |
1366 | compat_ulong_t __user *datap = compat_ptr(data); | |
1367 | compat_ulong_t word; | |
ae7795bc | 1368 | kernel_siginfo_t siginfo; |
032d82d9 RM |
1369 | int ret; |
1370 | ||
1371 | switch (request) { | |
1372 | case PTRACE_PEEKTEXT: | |
1373 | case PTRACE_PEEKDATA: | |
84d77d3f | 1374 | ret = ptrace_access_vm(child, addr, &word, sizeof(word), |
f307ab6d | 1375 | FOLL_FORCE); |
032d82d9 RM |
1376 | if (ret != sizeof(word)) |
1377 | ret = -EIO; | |
1378 | else | |
1379 | ret = put_user(word, datap); | |
1380 | break; | |
1381 | ||
1382 | case PTRACE_POKETEXT: | |
1383 | case PTRACE_POKEDATA: | |
84d77d3f | 1384 | ret = ptrace_access_vm(child, addr, &data, sizeof(data), |
f307ab6d | 1385 | FOLL_FORCE | FOLL_WRITE); |
032d82d9 RM |
1386 | ret = (ret != sizeof(data) ? -EIO : 0); |
1387 | break; | |
1388 | ||
1389 | case PTRACE_GETEVENTMSG: | |
1390 | ret = put_user((compat_ulong_t) child->ptrace_message, datap); | |
1391 | break; | |
1392 | ||
e16b2781 RM |
1393 | case PTRACE_GETSIGINFO: |
1394 | ret = ptrace_getsiginfo(child, &siginfo); | |
1395 | if (!ret) | |
1396 | ret = copy_siginfo_to_user32( | |
1397 | (struct compat_siginfo __user *) datap, | |
1398 | &siginfo); | |
1399 | break; | |
1400 | ||
1401 | case PTRACE_SETSIGINFO: | |
4cd2e0e7 EB |
1402 | ret = copy_siginfo_from_user32( |
1403 | &siginfo, (struct compat_siginfo __user *) datap); | |
1404 | if (!ret) | |
e16b2781 RM |
1405 | ret = ptrace_setsiginfo(child, &siginfo); |
1406 | break; | |
2225a122 SS |
1407 | #ifdef CONFIG_HAVE_ARCH_TRACEHOOK |
1408 | case PTRACE_GETREGSET: | |
1409 | case PTRACE_SETREGSET: | |
1410 | { | |
1411 | struct iovec kiov; | |
1412 | struct compat_iovec __user *uiov = | |
1413 | (struct compat_iovec __user *) datap; | |
1414 | compat_uptr_t ptr; | |
1415 | compat_size_t len; | |
1416 | ||
96d4f267 | 1417 | if (!access_ok(uiov, sizeof(*uiov))) |
2225a122 SS |
1418 | return -EFAULT; |
1419 | ||
1420 | if (__get_user(ptr, &uiov->iov_base) || | |
1421 | __get_user(len, &uiov->iov_len)) | |
1422 | return -EFAULT; | |
1423 | ||
1424 | kiov.iov_base = compat_ptr(ptr); | |
1425 | kiov.iov_len = len; | |
1426 | ||
1427 | ret = ptrace_regset(child, request, addr, &kiov); | |
1428 | if (!ret) | |
1429 | ret = __put_user(kiov.iov_len, &uiov->iov_len); | |
1430 | break; | |
1431 | } | |
1432 | #endif | |
e16b2781 | 1433 | |
032d82d9 RM |
1434 | default: |
1435 | ret = ptrace_request(child, request, addr, data); | |
1436 | } | |
1437 | ||
1438 | return ret; | |
1439 | } | |
c269f196 | 1440 | |
62a6fa97 HC |
1441 | COMPAT_SYSCALL_DEFINE4(ptrace, compat_long_t, request, compat_long_t, pid, |
1442 | compat_long_t, addr, compat_long_t, data) | |
c269f196 RM |
1443 | { |
1444 | struct task_struct *child; | |
1445 | long ret; | |
1446 | ||
c269f196 RM |
1447 | if (request == PTRACE_TRACEME) { |
1448 | ret = ptrace_traceme(); | |
1449 | goto out; | |
1450 | } | |
1451 | ||
2ee08260 MR |
1452 | child = find_get_task_by_vpid(pid); |
1453 | if (!child) { | |
1454 | ret = -ESRCH; | |
c269f196 RM |
1455 | goto out; |
1456 | } | |
1457 | ||
3544d72a | 1458 | if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) { |
aa9147c9 | 1459 | ret = ptrace_attach(child, request, addr, data); |
c269f196 RM |
1460 | /* |
1461 | * Some architectures need to do book-keeping after | |
1462 | * a ptrace attach. | |
1463 | */ | |
1464 | if (!ret) | |
1465 | arch_ptrace_attach(child); | |
1466 | goto out_put_task_struct; | |
1467 | } | |
1468 | ||
fca26f26 TH |
1469 | ret = ptrace_check_attach(child, request == PTRACE_KILL || |
1470 | request == PTRACE_INTERRUPT); | |
9899d11f | 1471 | if (!ret) { |
c269f196 | 1472 | ret = compat_arch_ptrace(child, request, addr, data); |
9899d11f ON |
1473 | if (ret || request != PTRACE_DETACH) |
1474 | ptrace_unfreeze_traced(child); | |
1475 | } | |
c269f196 RM |
1476 | |
1477 | out_put_task_struct: | |
1478 | put_task_struct(child); | |
1479 | out: | |
c269f196 RM |
1480 | return ret; |
1481 | } | |
96b8936a | 1482 | #endif /* CONFIG_COMPAT */ |