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> |
3f67987c | 35 | #include <linux/syscall_user_dispatch.h> |
1da177e4 | 36 | |
201766a2 EK |
37 | #include <asm/syscall.h> /* for syscall_get_* */ |
38 | ||
84d77d3f EB |
39 | /* |
40 | * Access another process' address space via ptrace. | |
41 | * Source/target buffer must be kernel space, | |
42 | * Do not walk the page table directly, use get_user_pages | |
43 | */ | |
44 | int ptrace_access_vm(struct task_struct *tsk, unsigned long addr, | |
45 | void *buf, int len, unsigned int gup_flags) | |
46 | { | |
47 | struct mm_struct *mm; | |
48 | int ret; | |
49 | ||
50 | mm = get_task_mm(tsk); | |
51 | if (!mm) | |
52 | return 0; | |
53 | ||
54 | if (!tsk->ptrace || | |
55 | (current != tsk->parent) || | |
56 | ((get_dumpable(mm) != SUID_DUMP_USER) && | |
57 | !ptracer_capable(tsk, mm->user_ns))) { | |
58 | mmput(mm); | |
59 | return 0; | |
60 | } | |
61 | ||
d3f5ffca | 62 | ret = __access_remote_vm(mm, addr, buf, len, gup_flags); |
84d77d3f EB |
63 | mmput(mm); |
64 | ||
65 | return ret; | |
66 | } | |
67 | ||
bf53de90 | 68 | |
c70d9d80 EB |
69 | void __ptrace_link(struct task_struct *child, struct task_struct *new_parent, |
70 | const struct cred *ptracer_cred) | |
71 | { | |
72 | BUG_ON(!list_empty(&child->ptrace_entry)); | |
73 | list_add(&child->ptrace_entry, &new_parent->ptraced); | |
74 | child->parent = new_parent; | |
75 | child->ptracer_cred = get_cred(ptracer_cred); | |
76 | } | |
77 | ||
1da177e4 LT |
78 | /* |
79 | * ptrace a task: make the debugger its new parent and | |
80 | * move it to the ptrace list. | |
81 | * | |
82 | * Must be called with the tasklist lock write-held. | |
83 | */ | |
c70d9d80 | 84 | static void ptrace_link(struct task_struct *child, struct task_struct *new_parent) |
1da177e4 | 85 | { |
6994eefb | 86 | __ptrace_link(child, new_parent, current_cred()); |
1da177e4 | 87 | } |
3a709703 | 88 | |
e3bd058f TH |
89 | /** |
90 | * __ptrace_unlink - unlink ptracee and restore its execution state | |
91 | * @child: ptracee to be unlinked | |
1da177e4 | 92 | * |
0e9f0a4a TH |
93 | * Remove @child from the ptrace list, move it back to the original parent, |
94 | * and restore the execution state so that it conforms to the group stop | |
95 | * state. | |
96 | * | |
97 | * Unlinking can happen via two paths - explicit PTRACE_DETACH or ptracer | |
98 | * exiting. For PTRACE_DETACH, unless the ptracee has been killed between | |
99 | * ptrace_check_attach() and here, it's guaranteed to be in TASK_TRACED. | |
100 | * If the ptracer is exiting, the ptracee can be in any state. | |
101 | * | |
102 | * After detach, the ptracee should be in a state which conforms to the | |
103 | * group stop. If the group is stopped or in the process of stopping, the | |
104 | * ptracee should be put into TASK_STOPPED; otherwise, it should be woken | |
105 | * up from TASK_TRACED. | |
106 | * | |
107 | * If the ptracee is in TASK_TRACED and needs to be moved to TASK_STOPPED, | |
108 | * it goes through TRACED -> RUNNING -> STOPPED transition which is similar | |
109 | * to but in the opposite direction of what happens while attaching to a | |
110 | * stopped task. However, in this direction, the intermediate RUNNING | |
111 | * state is not hidden even from the current ptracer and if it immediately | |
112 | * re-attaches and performs a WNOHANG wait(2), it may fail. | |
e3bd058f TH |
113 | * |
114 | * CONTEXT: | |
115 | * write_lock_irq(tasklist_lock) | |
1da177e4 | 116 | */ |
36c8b586 | 117 | void __ptrace_unlink(struct task_struct *child) |
1da177e4 | 118 | { |
64b875f7 | 119 | const struct cred *old_cred; |
5ecfbae0 ON |
120 | BUG_ON(!child->ptrace); |
121 | ||
64c19ba2 | 122 | clear_task_syscall_work(child, SYSCALL_TRACE); |
64eb35f7 GKB |
123 | #if defined(CONFIG_GENERIC_ENTRY) || defined(TIF_SYSCALL_EMU) |
124 | clear_task_syscall_work(child, SYSCALL_EMU); | |
15532fd6 | 125 | #endif |
0a5bf409 | 126 | |
f470021a RM |
127 | child->parent = child->real_parent; |
128 | list_del_init(&child->ptrace_entry); | |
64b875f7 EB |
129 | old_cred = child->ptracer_cred; |
130 | child->ptracer_cred = NULL; | |
131 | put_cred(old_cred); | |
1da177e4 | 132 | |
1da177e4 | 133 | spin_lock(&child->sighand->siglock); |
1333ab03 | 134 | child->ptrace = 0; |
73ddff2b TH |
135 | /* |
136 | * Clear all pending traps and TRAPPING. TRAPPING should be | |
137 | * cleared regardless of JOBCTL_STOP_PENDING. Do it explicitly. | |
138 | */ | |
139 | task_clear_jobctl_pending(child, JOBCTL_TRAP_MASK); | |
140 | task_clear_jobctl_trapping(child); | |
141 | ||
0e9f0a4a | 142 | /* |
a8f072c1 | 143 | * Reinstate JOBCTL_STOP_PENDING if group stop is in effect and |
0e9f0a4a TH |
144 | * @child isn't dead. |
145 | */ | |
146 | if (!(child->flags & PF_EXITING) && | |
147 | (child->signal->flags & SIGNAL_STOP_STOPPED || | |
8a88951b | 148 | child->signal->group_stop_count)) { |
a8f072c1 | 149 | child->jobctl |= JOBCTL_STOP_PENDING; |
0e9f0a4a | 150 | |
8a88951b ON |
151 | /* |
152 | * This is only possible if this thread was cloned by the | |
153 | * traced task running in the stopped group, set the signal | |
154 | * for the future reports. | |
155 | * FIXME: we should change ptrace_init_task() to handle this | |
156 | * case. | |
157 | */ | |
158 | if (!(child->jobctl & JOBCTL_STOP_SIGMASK)) | |
159 | child->jobctl |= SIGSTOP; | |
160 | } | |
161 | ||
0e9f0a4a TH |
162 | /* |
163 | * If transition to TASK_STOPPED is pending or in TASK_TRACED, kick | |
164 | * @child in the butt. Note that @resume should be used iff @child | |
165 | * is in TASK_TRACED; otherwise, we might unduly disrupt | |
166 | * TASK_KILLABLE sleeps. | |
167 | */ | |
a8f072c1 | 168 | if (child->jobctl & JOBCTL_STOP_PENDING || task_is_traced(child)) |
910ffdb1 | 169 | ptrace_signal_wake_up(child, true); |
0e9f0a4a | 170 | |
1da177e4 | 171 | spin_unlock(&child->sighand->siglock); |
1da177e4 LT |
172 | } |
173 | ||
dbb5afad ON |
174 | static bool looks_like_a_spurious_pid(struct task_struct *task) |
175 | { | |
176 | if (task->exit_code != ((PTRACE_EVENT_EXEC << 8) | SIGTRAP)) | |
177 | return false; | |
178 | ||
179 | if (task_pid_vnr(task) == task->ptrace_message) | |
180 | return false; | |
181 | /* | |
182 | * The tracee changed its pid but the PTRACE_EVENT_EXEC event | |
183 | * was not wait()'ed, most probably debugger targets the old | |
184 | * leader which was destroyed in de_thread(). | |
185 | */ | |
186 | return true; | |
187 | } | |
188 | ||
31cae1ea PZ |
189 | /* |
190 | * Ensure that nothing can wake it up, even SIGKILL | |
191 | * | |
192 | * A task is switched to this state while a ptrace operation is in progress; | |
193 | * such that the ptrace operation is uninterruptible. | |
194 | */ | |
9899d11f ON |
195 | static bool ptrace_freeze_traced(struct task_struct *task) |
196 | { | |
197 | bool ret = false; | |
198 | ||
199 | /* Lockless, nobody but us can set this flag */ | |
200 | if (task->jobctl & JOBCTL_LISTENING) | |
201 | return ret; | |
202 | ||
203 | spin_lock_irq(&task->sighand->siglock); | |
dbb5afad ON |
204 | if (task_is_traced(task) && !looks_like_a_spurious_pid(task) && |
205 | !__fatal_signal_pending(task)) { | |
2500ad1c | 206 | task->jobctl |= JOBCTL_PTRACE_FROZEN; |
9899d11f ON |
207 | ret = true; |
208 | } | |
209 | spin_unlock_irq(&task->sighand->siglock); | |
210 | ||
211 | return ret; | |
212 | } | |
213 | ||
214 | static void ptrace_unfreeze_traced(struct task_struct *task) | |
215 | { | |
2500ad1c | 216 | unsigned long flags; |
9899d11f | 217 | |
5402e97a | 218 | /* |
2500ad1c EB |
219 | * The child may be awake and may have cleared |
220 | * JOBCTL_PTRACE_FROZEN (see ptrace_resume). The child will | |
221 | * not set JOBCTL_PTRACE_FROZEN or enter __TASK_TRACED anew. | |
5402e97a | 222 | */ |
2500ad1c EB |
223 | if (lock_task_sighand(task, &flags)) { |
224 | task->jobctl &= ~JOBCTL_PTRACE_FROZEN; | |
31cae1ea | 225 | if (__fatal_signal_pending(task)) { |
de2a3477 | 226 | task->jobctl &= ~JOBCTL_TRACED; |
5402e97a | 227 | wake_up_state(task, __TASK_TRACED); |
31cae1ea | 228 | } |
2500ad1c | 229 | unlock_task_sighand(task, &flags); |
5402e97a | 230 | } |
9899d11f ON |
231 | } |
232 | ||
755e276b TH |
233 | /** |
234 | * ptrace_check_attach - check whether ptracee is ready for ptrace operation | |
235 | * @child: ptracee to check for | |
236 | * @ignore_state: don't check whether @child is currently %TASK_TRACED | |
237 | * | |
238 | * Check whether @child is being ptraced by %current and ready for further | |
239 | * ptrace operations. If @ignore_state is %false, @child also should be in | |
240 | * %TASK_TRACED state and on return the child is guaranteed to be traced | |
241 | * and not executing. If @ignore_state is %true, @child can be in any | |
242 | * state. | |
243 | * | |
244 | * CONTEXT: | |
245 | * Grabs and releases tasklist_lock and @child->sighand->siglock. | |
246 | * | |
247 | * RETURNS: | |
248 | * 0 on success, -ESRCH if %child is not ready. | |
1da177e4 | 249 | */ |
edea0d03 | 250 | static int ptrace_check_attach(struct task_struct *child, bool ignore_state) |
1da177e4 LT |
251 | { |
252 | int ret = -ESRCH; | |
253 | ||
254 | /* | |
255 | * We take the read lock around doing both checks to close a | |
256 | * possible race where someone else was tracing our child and | |
257 | * detached between these two checks. After this locked check, | |
258 | * we are sure that this is our traced child and that can only | |
259 | * be changed by us so it's not changing right after this. | |
260 | */ | |
261 | read_lock(&tasklist_lock); | |
9899d11f | 262 | if (child->ptrace && child->parent == current) { |
c0c0b649 ON |
263 | /* |
264 | * child->sighand can't be NULL, release_task() | |
265 | * does ptrace_unlink() before __exit_signal(). | |
266 | */ | |
9899d11f | 267 | if (ignore_state || ptrace_freeze_traced(child)) |
321fb561 | 268 | ret = 0; |
1da177e4 LT |
269 | } |
270 | read_unlock(&tasklist_lock); | |
271 | ||
7b0fe136 | 272 | if (!ret && !ignore_state && |
f5d39b02 | 273 | WARN_ON_ONCE(!wait_task_inactive(child, __TASK_TRACED|TASK_FROZEN))) |
7b0fe136 | 274 | ret = -ESRCH; |
1da177e4 | 275 | |
1da177e4 LT |
276 | return ret; |
277 | } | |
278 | ||
cf237052 | 279 | static bool ptrace_has_cap(struct user_namespace *ns, unsigned int mode) |
69f594a3 EP |
280 | { |
281 | if (mode & PTRACE_MODE_NOAUDIT) | |
cf237052 MS |
282 | return ns_capable_noaudit(ns, CAP_SYS_PTRACE); |
283 | return ns_capable(ns, CAP_SYS_PTRACE); | |
69f594a3 EP |
284 | } |
285 | ||
9f99798f TH |
286 | /* Returns 0 on success, -errno on denial. */ |
287 | static int __ptrace_may_access(struct task_struct *task, unsigned int mode) | |
ab8d11be | 288 | { |
c69e8d9c | 289 | const struct cred *cred = current_cred(), *tcred; |
bfedb589 | 290 | struct mm_struct *mm; |
caaee623 JH |
291 | kuid_t caller_uid; |
292 | kgid_t caller_gid; | |
293 | ||
294 | if (!(mode & PTRACE_MODE_FSCREDS) == !(mode & PTRACE_MODE_REALCREDS)) { | |
295 | WARN(1, "denying ptrace access check without PTRACE_MODE_*CREDS\n"); | |
296 | return -EPERM; | |
297 | } | |
b6dff3ec | 298 | |
df26c40e EB |
299 | /* May we inspect the given task? |
300 | * This check is used both for attaching with ptrace | |
301 | * and for allowing access to sensitive information in /proc. | |
302 | * | |
303 | * ptrace_attach denies several cases that /proc allows | |
304 | * because setting up the necessary parent/child relationship | |
305 | * or halting the specified task is impossible. | |
306 | */ | |
caaee623 | 307 | |
df26c40e | 308 | /* Don't let security modules deny introspection */ |
73af963f | 309 | if (same_thread_group(task, current)) |
df26c40e | 310 | return 0; |
c69e8d9c | 311 | rcu_read_lock(); |
caaee623 JH |
312 | if (mode & PTRACE_MODE_FSCREDS) { |
313 | caller_uid = cred->fsuid; | |
314 | caller_gid = cred->fsgid; | |
315 | } else { | |
316 | /* | |
317 | * Using the euid would make more sense here, but something | |
318 | * in userland might rely on the old behavior, and this | |
319 | * shouldn't be a security problem since | |
320 | * PTRACE_MODE_REALCREDS implies that the caller explicitly | |
321 | * used a syscall that requests access to another process | |
322 | * (and not a filesystem syscall to procfs). | |
323 | */ | |
324 | caller_uid = cred->uid; | |
325 | caller_gid = cred->gid; | |
326 | } | |
c69e8d9c | 327 | tcred = __task_cred(task); |
caaee623 JH |
328 | if (uid_eq(caller_uid, tcred->euid) && |
329 | uid_eq(caller_uid, tcred->suid) && | |
330 | uid_eq(caller_uid, tcred->uid) && | |
331 | gid_eq(caller_gid, tcred->egid) && | |
332 | gid_eq(caller_gid, tcred->sgid) && | |
333 | gid_eq(caller_gid, tcred->gid)) | |
8409cca7 | 334 | goto ok; |
cf237052 | 335 | if (ptrace_has_cap(tcred->user_ns, mode)) |
8409cca7 SH |
336 | goto ok; |
337 | rcu_read_unlock(); | |
338 | return -EPERM; | |
339 | ok: | |
c69e8d9c | 340 | rcu_read_unlock(); |
f6581f5b JH |
341 | /* |
342 | * If a task drops privileges and becomes nondumpable (through a syscall | |
343 | * like setresuid()) while we are trying to access it, we must ensure | |
344 | * that the dumpability is read after the credentials; otherwise, | |
345 | * we may be able to attach to a task that we shouldn't be able to | |
346 | * attach to (as if the task had dropped privileges without becoming | |
347 | * nondumpable). | |
348 | * Pairs with a write barrier in commit_creds(). | |
349 | */ | |
350 | smp_rmb(); | |
bfedb589 EB |
351 | mm = task->mm; |
352 | if (mm && | |
353 | ((get_dumpable(mm) != SUID_DUMP_USER) && | |
cf237052 | 354 | !ptrace_has_cap(mm->user_ns, mode))) |
bfedb589 | 355 | return -EPERM; |
ab8d11be | 356 | |
9e48858f | 357 | return security_ptrace_access_check(task, mode); |
ab8d11be MS |
358 | } |
359 | ||
006ebb40 | 360 | bool ptrace_may_access(struct task_struct *task, unsigned int mode) |
ab8d11be MS |
361 | { |
362 | int err; | |
363 | task_lock(task); | |
006ebb40 | 364 | err = __ptrace_may_access(task, mode); |
ab8d11be | 365 | task_unlock(task); |
3a709703 | 366 | return !err; |
ab8d11be MS |
367 | } |
368 | ||
ee1fee90 JH |
369 | static int check_ptrace_options(unsigned long data) |
370 | { | |
371 | if (data & ~(unsigned long)PTRACE_O_MASK) | |
372 | return -EINVAL; | |
373 | ||
374 | if (unlikely(data & PTRACE_O_SUSPEND_SECCOMP)) { | |
375 | if (!IS_ENABLED(CONFIG_CHECKPOINT_RESTORE) || | |
376 | !IS_ENABLED(CONFIG_SECCOMP)) | |
377 | return -EINVAL; | |
378 | ||
379 | if (!capable(CAP_SYS_ADMIN)) | |
380 | return -EPERM; | |
381 | ||
382 | if (seccomp_mode(¤t->seccomp) != SECCOMP_MODE_DISABLED || | |
383 | current->ptrace & PT_SUSPEND_SECCOMP) | |
384 | return -EPERM; | |
385 | } | |
386 | return 0; | |
387 | } | |
388 | ||
3544d72a | 389 | static int ptrace_attach(struct task_struct *task, long request, |
aa9147c9 | 390 | unsigned long addr, |
3544d72a | 391 | unsigned long flags) |
1da177e4 | 392 | { |
3544d72a | 393 | bool seize = (request == PTRACE_SEIZE); |
1da177e4 | 394 | int retval; |
f5b40e36 | 395 | |
3544d72a | 396 | retval = -EIO; |
aa9147c9 DV |
397 | if (seize) { |
398 | if (addr != 0) | |
399 | goto out; | |
ee1fee90 JH |
400 | /* |
401 | * This duplicates the check in check_ptrace_options() because | |
402 | * ptrace_attach() and ptrace_setoptions() have historically | |
403 | * used different error codes for unknown ptrace options. | |
404 | */ | |
aa9147c9 DV |
405 | if (flags & ~(unsigned long)PTRACE_O_MASK) |
406 | goto out; | |
ee1fee90 JH |
407 | retval = check_ptrace_options(flags); |
408 | if (retval) | |
409 | return retval; | |
aa9147c9 DV |
410 | flags = PT_PTRACED | PT_SEIZED | (flags << PT_OPT_FLAG_SHIFT); |
411 | } else { | |
412 | flags = PT_PTRACED; | |
413 | } | |
3544d72a | 414 | |
a5cb013d AV |
415 | audit_ptrace(task); |
416 | ||
1da177e4 | 417 | retval = -EPERM; |
e8b33b8c | 418 | if (unlikely(task->flags & PF_KTHREAD)) |
b79b7ba9 | 419 | goto out; |
bac0abd6 | 420 | if (same_thread_group(task, current)) |
f5b40e36 LT |
421 | goto out; |
422 | ||
f2f0b00a ON |
423 | /* |
424 | * Protect exec's credential calculations against our interference; | |
86b6c1f3 | 425 | * SUID, SGID and LSM creds get determined differently |
5e751e99 | 426 | * under ptrace. |
d84f4f99 | 427 | */ |
793285fc | 428 | retval = -ERESTARTNOINTR; |
9b1bf12d | 429 | if (mutex_lock_interruptible(&task->signal->cred_guard_mutex)) |
d84f4f99 | 430 | goto out; |
f5b40e36 | 431 | |
4b105cbb | 432 | task_lock(task); |
caaee623 | 433 | retval = __ptrace_may_access(task, PTRACE_MODE_ATTACH_REALCREDS); |
4b105cbb | 434 | task_unlock(task); |
1da177e4 | 435 | if (retval) |
4b105cbb | 436 | goto unlock_creds; |
1da177e4 | 437 | |
4b105cbb | 438 | write_lock_irq(&tasklist_lock); |
b79b7ba9 ON |
439 | retval = -EPERM; |
440 | if (unlikely(task->exit_state)) | |
4b105cbb | 441 | goto unlock_tasklist; |
f2f0b00a | 442 | if (task->ptrace) |
4b105cbb | 443 | goto unlock_tasklist; |
b79b7ba9 | 444 | |
aa9147c9 | 445 | task->ptrace = flags; |
1da177e4 | 446 | |
c70d9d80 | 447 | ptrace_link(task, current); |
3544d72a TH |
448 | |
449 | /* SEIZE doesn't trap tracee on attach */ | |
450 | if (!seize) | |
079b22dc | 451 | send_sig_info(SIGSTOP, SEND_SIG_PRIV, task); |
b79b7ba9 | 452 | |
d79fdd6d TH |
453 | spin_lock(&task->sighand->siglock); |
454 | ||
455 | /* | |
73ddff2b | 456 | * If the task is already STOPPED, set JOBCTL_TRAP_STOP and |
d79fdd6d TH |
457 | * TRAPPING, and kick it so that it transits to TRACED. TRAPPING |
458 | * will be cleared if the child completes the transition or any | |
459 | * event which clears the group stop states happens. We'll wait | |
460 | * for the transition to complete before returning from this | |
461 | * function. | |
462 | * | |
463 | * This hides STOPPED -> RUNNING -> TRACED transition from the | |
464 | * attaching thread but a different thread in the same group can | |
465 | * still observe the transient RUNNING state. IOW, if another | |
466 | * thread's WNOHANG wait(2) on the stopped tracee races against | |
467 | * ATTACH, the wait(2) may fail due to the transient RUNNING. | |
468 | * | |
469 | * The following task_is_stopped() test is safe as both transitions | |
470 | * in and out of STOPPED are protected by siglock. | |
471 | */ | |
7dd3db54 | 472 | if (task_is_stopped(task) && |
31cae1ea PZ |
473 | task_set_jobctl_pending(task, JOBCTL_TRAP_STOP | JOBCTL_TRAPPING)) { |
474 | task->jobctl &= ~JOBCTL_STOPPED; | |
910ffdb1 | 475 | signal_wake_up_state(task, __TASK_STOPPED); |
31cae1ea | 476 | } |
d79fdd6d TH |
477 | |
478 | spin_unlock(&task->sighand->siglock); | |
479 | ||
b79b7ba9 | 480 | retval = 0; |
4b105cbb ON |
481 | unlock_tasklist: |
482 | write_unlock_irq(&tasklist_lock); | |
483 | unlock_creds: | |
9b1bf12d | 484 | mutex_unlock(&task->signal->cred_guard_mutex); |
f5b40e36 | 485 | out: |
f701e5b7 | 486 | if (!retval) { |
7c3b00e0 ON |
487 | /* |
488 | * We do not bother to change retval or clear JOBCTL_TRAPPING | |
489 | * if wait_on_bit() was interrupted by SIGKILL. The tracer will | |
490 | * not return to user-mode, it will exit and clear this bit in | |
491 | * __ptrace_unlink() if it wasn't already cleared by the tracee; | |
492 | * and until then nobody can ptrace this task. | |
493 | */ | |
494 | wait_on_bit(&task->jobctl, JOBCTL_TRAPPING_BIT, TASK_KILLABLE); | |
f701e5b7 VZ |
495 | proc_ptrace_connector(task, PTRACE_ATTACH); |
496 | } | |
497 | ||
1da177e4 LT |
498 | return retval; |
499 | } | |
500 | ||
f2f0b00a ON |
501 | /** |
502 | * ptrace_traceme -- helper for PTRACE_TRACEME | |
503 | * | |
504 | * Performs checks and sets PT_PTRACED. | |
505 | * Should be used by all ptrace implementations for PTRACE_TRACEME. | |
506 | */ | |
e3e89cc5 | 507 | static int ptrace_traceme(void) |
f2f0b00a ON |
508 | { |
509 | int ret = -EPERM; | |
510 | ||
4b105cbb ON |
511 | write_lock_irq(&tasklist_lock); |
512 | /* Are we already being traced? */ | |
f2f0b00a | 513 | if (!current->ptrace) { |
f2f0b00a | 514 | ret = security_ptrace_traceme(current->parent); |
f2f0b00a ON |
515 | /* |
516 | * Check PF_EXITING to ensure ->real_parent has not passed | |
517 | * exit_ptrace(). Otherwise we don't report the error but | |
518 | * pretend ->real_parent untraces us right after return. | |
519 | */ | |
520 | if (!ret && !(current->real_parent->flags & PF_EXITING)) { | |
521 | current->ptrace = PT_PTRACED; | |
c70d9d80 | 522 | ptrace_link(current, current->real_parent); |
f2f0b00a | 523 | } |
f2f0b00a | 524 | } |
4b105cbb ON |
525 | write_unlock_irq(&tasklist_lock); |
526 | ||
f2f0b00a ON |
527 | return ret; |
528 | } | |
529 | ||
39c626ae ON |
530 | /* |
531 | * Called with irqs disabled, returns true if childs should reap themselves. | |
532 | */ | |
533 | static int ignoring_children(struct sighand_struct *sigh) | |
534 | { | |
535 | int ret; | |
536 | spin_lock(&sigh->siglock); | |
537 | ret = (sigh->action[SIGCHLD-1].sa.sa_handler == SIG_IGN) || | |
538 | (sigh->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT); | |
539 | spin_unlock(&sigh->siglock); | |
540 | return ret; | |
541 | } | |
542 | ||
543 | /* | |
544 | * Called with tasklist_lock held for writing. | |
545 | * Unlink a traced task, and clean it up if it was a traced zombie. | |
546 | * Return true if it needs to be reaped with release_task(). | |
547 | * (We can't call release_task() here because we already hold tasklist_lock.) | |
548 | * | |
549 | * If it's a zombie, our attachedness prevented normal parent notification | |
550 | * or self-reaping. Do notification now if it would have happened earlier. | |
551 | * If it should reap itself, return true. | |
552 | * | |
a7f0765e ON |
553 | * If it's our own child, there is no notification to do. But if our normal |
554 | * children self-reap, then this child was prevented by ptrace and we must | |
555 | * reap it now, in that case we must also wake up sub-threads sleeping in | |
556 | * do_wait(). | |
39c626ae ON |
557 | */ |
558 | static bool __ptrace_detach(struct task_struct *tracer, struct task_struct *p) | |
559 | { | |
9843a1e9 ON |
560 | bool dead; |
561 | ||
39c626ae ON |
562 | __ptrace_unlink(p); |
563 | ||
9843a1e9 ON |
564 | if (p->exit_state != EXIT_ZOMBIE) |
565 | return false; | |
566 | ||
567 | dead = !thread_group_leader(p); | |
568 | ||
569 | if (!dead && thread_group_empty(p)) { | |
570 | if (!same_thread_group(p->real_parent, tracer)) | |
571 | dead = do_notify_parent(p, p->exit_signal); | |
572 | else if (ignoring_children(tracer->sighand)) { | |
573 | __wake_up_parent(p, tracer); | |
9843a1e9 | 574 | dead = true; |
39c626ae ON |
575 | } |
576 | } | |
9843a1e9 ON |
577 | /* Mark it as in the process of being reaped. */ |
578 | if (dead) | |
579 | p->exit_state = EXIT_DEAD; | |
580 | return dead; | |
39c626ae ON |
581 | } |
582 | ||
e3e89cc5 | 583 | static int ptrace_detach(struct task_struct *child, unsigned int data) |
1da177e4 | 584 | { |
7ed20e1a | 585 | if (!valid_signal(data)) |
5ecfbae0 | 586 | return -EIO; |
1da177e4 LT |
587 | |
588 | /* Architecture-specific hardware disable .. */ | |
589 | ptrace_disable(child); | |
590 | ||
95c3eb76 | 591 | write_lock_irq(&tasklist_lock); |
39c626ae | 592 | /* |
64a4096c ON |
593 | * We rely on ptrace_freeze_traced(). It can't be killed and |
594 | * untraced by another thread, it can't be a zombie. | |
39c626ae | 595 | */ |
64a4096c ON |
596 | WARN_ON(!child->ptrace || child->exit_state); |
597 | /* | |
598 | * tasklist_lock avoids the race with wait_task_stopped(), see | |
599 | * the comment in ptrace_resume(). | |
600 | */ | |
601 | child->exit_code = data; | |
602 | __ptrace_detach(current, child); | |
1da177e4 LT |
603 | write_unlock_irq(&tasklist_lock); |
604 | ||
f701e5b7 | 605 | proc_ptrace_connector(child, PTRACE_DETACH); |
4576145c | 606 | |
1da177e4 LT |
607 | return 0; |
608 | } | |
609 | ||
39c626ae | 610 | /* |
c7e49c14 | 611 | * Detach all tasks we were using ptrace on. Called with tasklist held |
7c8bd232 | 612 | * for writing. |
39c626ae | 613 | */ |
7c8bd232 | 614 | void exit_ptrace(struct task_struct *tracer, struct list_head *dead) |
39c626ae ON |
615 | { |
616 | struct task_struct *p, *n; | |
c7e49c14 | 617 | |
39c626ae | 618 | list_for_each_entry_safe(p, n, &tracer->ptraced, ptrace_entry) { |
992fb6e1 | 619 | if (unlikely(p->ptrace & PT_EXITKILL)) |
079b22dc | 620 | send_sig_info(SIGKILL, SEND_SIG_PRIV, p); |
992fb6e1 | 621 | |
39c626ae | 622 | if (__ptrace_detach(tracer, p)) |
7c8bd232 | 623 | list_add(&p->ptrace_entry, dead); |
39c626ae ON |
624 | } |
625 | } | |
626 | ||
1da177e4 LT |
627 | int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len) |
628 | { | |
629 | int copied = 0; | |
630 | ||
631 | while (len > 0) { | |
632 | char buf[128]; | |
633 | int this_len, retval; | |
634 | ||
635 | this_len = (len > sizeof(buf)) ? sizeof(buf) : len; | |
84d77d3f EB |
636 | retval = ptrace_access_vm(tsk, src, buf, this_len, FOLL_FORCE); |
637 | ||
1da177e4 LT |
638 | if (!retval) { |
639 | if (copied) | |
640 | break; | |
641 | return -EIO; | |
642 | } | |
643 | if (copy_to_user(dst, buf, retval)) | |
644 | return -EFAULT; | |
645 | copied += retval; | |
646 | src += retval; | |
647 | dst += retval; | |
3a709703 | 648 | len -= retval; |
1da177e4 LT |
649 | } |
650 | return copied; | |
651 | } | |
652 | ||
653 | int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len) | |
654 | { | |
655 | int copied = 0; | |
656 | ||
657 | while (len > 0) { | |
658 | char buf[128]; | |
659 | int this_len, retval; | |
660 | ||
661 | this_len = (len > sizeof(buf)) ? sizeof(buf) : len; | |
662 | if (copy_from_user(buf, src, this_len)) | |
663 | return -EFAULT; | |
84d77d3f | 664 | retval = ptrace_access_vm(tsk, dst, buf, this_len, |
f307ab6d | 665 | FOLL_FORCE | FOLL_WRITE); |
1da177e4 LT |
666 | if (!retval) { |
667 | if (copied) | |
668 | break; | |
669 | return -EIO; | |
670 | } | |
671 | copied += retval; | |
672 | src += retval; | |
673 | dst += retval; | |
3a709703 | 674 | len -= retval; |
1da177e4 LT |
675 | } |
676 | return copied; | |
677 | } | |
678 | ||
4abf9869 | 679 | static int ptrace_setoptions(struct task_struct *child, unsigned long data) |
1da177e4 | 680 | { |
86b6c1f3 | 681 | unsigned flags; |
ee1fee90 | 682 | int ret; |
86b6c1f3 | 683 | |
ee1fee90 JH |
684 | ret = check_ptrace_options(data); |
685 | if (ret) | |
686 | return ret; | |
13c4a901 | 687 | |
86b6c1f3 DV |
688 | /* Avoid intermediate state when all opts are cleared */ |
689 | flags = child->ptrace; | |
690 | flags &= ~(PTRACE_O_MASK << PT_OPT_FLAG_SHIFT); | |
691 | flags |= (data << PT_OPT_FLAG_SHIFT); | |
692 | child->ptrace = flags; | |
1da177e4 | 693 | |
8c5cf9e5 | 694 | return 0; |
1da177e4 LT |
695 | } |
696 | ||
ae7795bc | 697 | static int ptrace_getsiginfo(struct task_struct *child, kernel_siginfo_t *info) |
1da177e4 | 698 | { |
e4961254 | 699 | unsigned long flags; |
1da177e4 LT |
700 | int error = -ESRCH; |
701 | ||
e4961254 | 702 | if (lock_task_sighand(child, &flags)) { |
1da177e4 | 703 | error = -EINVAL; |
1da177e4 | 704 | if (likely(child->last_siginfo != NULL)) { |
0752d7bf | 705 | copy_siginfo(info, child->last_siginfo); |
1da177e4 LT |
706 | error = 0; |
707 | } | |
e4961254 | 708 | unlock_task_sighand(child, &flags); |
1da177e4 | 709 | } |
1da177e4 LT |
710 | return error; |
711 | } | |
712 | ||
ae7795bc | 713 | static int ptrace_setsiginfo(struct task_struct *child, const kernel_siginfo_t *info) |
1da177e4 | 714 | { |
e4961254 | 715 | unsigned long flags; |
1da177e4 LT |
716 | int error = -ESRCH; |
717 | ||
e4961254 | 718 | if (lock_task_sighand(child, &flags)) { |
1da177e4 | 719 | error = -EINVAL; |
1da177e4 | 720 | if (likely(child->last_siginfo != NULL)) { |
0752d7bf | 721 | copy_siginfo(child->last_siginfo, info); |
1da177e4 LT |
722 | error = 0; |
723 | } | |
e4961254 | 724 | unlock_task_sighand(child, &flags); |
1da177e4 | 725 | } |
1da177e4 LT |
726 | return error; |
727 | } | |
728 | ||
84c751bd AV |
729 | static int ptrace_peek_siginfo(struct task_struct *child, |
730 | unsigned long addr, | |
731 | unsigned long data) | |
732 | { | |
733 | struct ptrace_peeksiginfo_args arg; | |
734 | struct sigpending *pending; | |
735 | struct sigqueue *q; | |
736 | int ret, i; | |
737 | ||
738 | ret = copy_from_user(&arg, (void __user *) addr, | |
739 | sizeof(struct ptrace_peeksiginfo_args)); | |
740 | if (ret) | |
741 | return -EFAULT; | |
742 | ||
743 | if (arg.flags & ~PTRACE_PEEKSIGINFO_SHARED) | |
744 | return -EINVAL; /* unknown flags */ | |
745 | ||
746 | if (arg.nr < 0) | |
747 | return -EINVAL; | |
748 | ||
f6e2aa91 EB |
749 | /* Ensure arg.off fits in an unsigned long */ |
750 | if (arg.off > ULONG_MAX) | |
751 | return 0; | |
752 | ||
84c751bd AV |
753 | if (arg.flags & PTRACE_PEEKSIGINFO_SHARED) |
754 | pending = &child->signal->shared_pending; | |
755 | else | |
756 | pending = &child->pending; | |
757 | ||
758 | for (i = 0; i < arg.nr; ) { | |
ae7795bc | 759 | kernel_siginfo_t info; |
f6e2aa91 EB |
760 | unsigned long off = arg.off + i; |
761 | bool found = false; | |
84c751bd AV |
762 | |
763 | spin_lock_irq(&child->sighand->siglock); | |
764 | list_for_each_entry(q, &pending->list, list) { | |
765 | if (!off--) { | |
f6e2aa91 | 766 | found = true; |
84c751bd AV |
767 | copy_siginfo(&info, &q->info); |
768 | break; | |
769 | } | |
770 | } | |
771 | spin_unlock_irq(&child->sighand->siglock); | |
772 | ||
f6e2aa91 | 773 | if (!found) /* beyond the end of the list */ |
84c751bd AV |
774 | break; |
775 | ||
776 | #ifdef CONFIG_COMPAT | |
5c465217 | 777 | if (unlikely(in_compat_syscall())) { |
84c751bd AV |
778 | compat_siginfo_t __user *uinfo = compat_ptr(data); |
779 | ||
cc731525 | 780 | if (copy_siginfo_to_user32(uinfo, &info)) { |
706b23bd MD |
781 | ret = -EFAULT; |
782 | break; | |
783 | } | |
784 | ||
84c751bd AV |
785 | } else |
786 | #endif | |
787 | { | |
788 | siginfo_t __user *uinfo = (siginfo_t __user *) data; | |
789 | ||
cc731525 | 790 | if (copy_siginfo_to_user(uinfo, &info)) { |
706b23bd MD |
791 | ret = -EFAULT; |
792 | break; | |
793 | } | |
84c751bd AV |
794 | } |
795 | ||
796 | data += sizeof(siginfo_t); | |
797 | i++; | |
798 | ||
799 | if (signal_pending(current)) | |
800 | break; | |
801 | ||
802 | cond_resched(); | |
803 | } | |
804 | ||
805 | if (i > 0) | |
806 | return i; | |
807 | ||
808 | return ret; | |
809 | } | |
36df29d7 | 810 | |
90f093fa PF |
811 | #ifdef CONFIG_RSEQ |
812 | static long ptrace_get_rseq_configuration(struct task_struct *task, | |
813 | unsigned long size, void __user *data) | |
814 | { | |
815 | struct ptrace_rseq_configuration conf = { | |
816 | .rseq_abi_pointer = (u64)(uintptr_t)task->rseq, | |
ee3e3ac0 | 817 | .rseq_abi_size = task->rseq_len, |
90f093fa PF |
818 | .signature = task->rseq_sig, |
819 | .flags = 0, | |
820 | }; | |
821 | ||
822 | size = min_t(unsigned long, size, sizeof(conf)); | |
823 | if (copy_to_user(data, &conf, size)) | |
824 | return -EFAULT; | |
825 | return sizeof(conf); | |
826 | } | |
827 | #endif | |
828 | ||
36df29d7 | 829 | #define is_singlestep(request) ((request) == PTRACE_SINGLESTEP) |
36df29d7 | 830 | |
5b88abbf RM |
831 | #ifdef PTRACE_SINGLEBLOCK |
832 | #define is_singleblock(request) ((request) == PTRACE_SINGLEBLOCK) | |
833 | #else | |
834 | #define is_singleblock(request) 0 | |
835 | #endif | |
836 | ||
36df29d7 RM |
837 | #ifdef PTRACE_SYSEMU |
838 | #define is_sysemu_singlestep(request) ((request) == PTRACE_SYSEMU_SINGLESTEP) | |
839 | #else | |
840 | #define is_sysemu_singlestep(request) 0 | |
841 | #endif | |
842 | ||
4abf9869 NK |
843 | static int ptrace_resume(struct task_struct *child, long request, |
844 | unsigned long data) | |
36df29d7 RM |
845 | { |
846 | if (!valid_signal(data)) | |
847 | return -EIO; | |
848 | ||
849 | if (request == PTRACE_SYSCALL) | |
64c19ba2 | 850 | set_task_syscall_work(child, SYSCALL_TRACE); |
36df29d7 | 851 | else |
64c19ba2 | 852 | clear_task_syscall_work(child, SYSCALL_TRACE); |
36df29d7 | 853 | |
64eb35f7 | 854 | #if defined(CONFIG_GENERIC_ENTRY) || defined(TIF_SYSCALL_EMU) |
36df29d7 | 855 | if (request == PTRACE_SYSEMU || request == PTRACE_SYSEMU_SINGLESTEP) |
64eb35f7 | 856 | set_task_syscall_work(child, SYSCALL_EMU); |
36df29d7 | 857 | else |
64eb35f7 | 858 | clear_task_syscall_work(child, SYSCALL_EMU); |
36df29d7 RM |
859 | #endif |
860 | ||
5b88abbf RM |
861 | if (is_singleblock(request)) { |
862 | if (unlikely(!arch_has_block_step())) | |
863 | return -EIO; | |
864 | user_enable_block_step(child); | |
865 | } else if (is_singlestep(request) || is_sysemu_singlestep(request)) { | |
36df29d7 RM |
866 | if (unlikely(!arch_has_single_step())) |
867 | return -EIO; | |
868 | user_enable_single_step(child); | |
3a709703 | 869 | } else { |
36df29d7 | 870 | user_disable_single_step(child); |
3a709703 | 871 | } |
36df29d7 | 872 | |
b72c1869 ON |
873 | /* |
874 | * Change ->exit_code and ->state under siglock to avoid the race | |
875 | * with wait_task_stopped() in between; a non-zero ->exit_code will | |
876 | * wrongly look like another report from tracee. | |
877 | * | |
878 | * Note that we need siglock even if ->exit_code == data and/or this | |
879 | * status was not reported yet, the new status must not be cleared by | |
880 | * wait_task_stopped() after resume. | |
b72c1869 | 881 | */ |
5b4197cb | 882 | spin_lock_irq(&child->sighand->siglock); |
36df29d7 | 883 | child->exit_code = data; |
31cae1ea | 884 | child->jobctl &= ~JOBCTL_TRACED; |
0666fb51 | 885 | wake_up_state(child, __TASK_TRACED); |
5b4197cb | 886 | spin_unlock_irq(&child->sighand->siglock); |
36df29d7 RM |
887 | |
888 | return 0; | |
889 | } | |
890 | ||
2225a122 SS |
891 | #ifdef CONFIG_HAVE_ARCH_TRACEHOOK |
892 | ||
893 | static const struct user_regset * | |
894 | find_regset(const struct user_regset_view *view, unsigned int type) | |
895 | { | |
896 | const struct user_regset *regset; | |
897 | int n; | |
898 | ||
899 | for (n = 0; n < view->n; ++n) { | |
900 | regset = view->regsets + n; | |
901 | if (regset->core_note_type == type) | |
902 | return regset; | |
903 | } | |
904 | ||
905 | return NULL; | |
906 | } | |
907 | ||
908 | static int ptrace_regset(struct task_struct *task, int req, unsigned int type, | |
909 | struct iovec *kiov) | |
910 | { | |
911 | const struct user_regset_view *view = task_user_regset_view(task); | |
912 | const struct user_regset *regset = find_regset(view, type); | |
913 | int regset_no; | |
914 | ||
915 | if (!regset || (kiov->iov_len % regset->size) != 0) | |
c6a0dd7e | 916 | return -EINVAL; |
2225a122 SS |
917 | |
918 | regset_no = regset - view->regsets; | |
919 | kiov->iov_len = min(kiov->iov_len, | |
920 | (__kernel_size_t) (regset->n * regset->size)); | |
921 | ||
922 | if (req == PTRACE_GETREGSET) | |
923 | return copy_regset_to_user(task, view, regset_no, 0, | |
924 | kiov->iov_len, kiov->iov_base); | |
925 | else | |
926 | return copy_regset_from_user(task, view, regset_no, 0, | |
927 | kiov->iov_len, kiov->iov_base); | |
928 | } | |
929 | ||
e8440c14 JS |
930 | /* |
931 | * This is declared in linux/regset.h and defined in machine-dependent | |
932 | * code. We put the export here, near the primary machine-neutral use, | |
933 | * to ensure no machine forgets it. | |
934 | */ | |
935 | EXPORT_SYMBOL_GPL(task_user_regset_view); | |
201766a2 EK |
936 | |
937 | static unsigned long | |
938 | ptrace_get_syscall_info_entry(struct task_struct *child, struct pt_regs *regs, | |
939 | struct ptrace_syscall_info *info) | |
940 | { | |
941 | unsigned long args[ARRAY_SIZE(info->entry.args)]; | |
942 | int i; | |
943 | ||
944 | info->op = PTRACE_SYSCALL_INFO_ENTRY; | |
945 | info->entry.nr = syscall_get_nr(child, regs); | |
946 | syscall_get_arguments(child, regs, args); | |
947 | for (i = 0; i < ARRAY_SIZE(args); i++) | |
948 | info->entry.args[i] = args[i]; | |
949 | ||
950 | /* args is the last field in struct ptrace_syscall_info.entry */ | |
951 | return offsetofend(struct ptrace_syscall_info, entry.args); | |
952 | } | |
953 | ||
954 | static unsigned long | |
955 | ptrace_get_syscall_info_seccomp(struct task_struct *child, struct pt_regs *regs, | |
956 | struct ptrace_syscall_info *info) | |
957 | { | |
958 | /* | |
959 | * As struct ptrace_syscall_info.entry is currently a subset | |
960 | * of struct ptrace_syscall_info.seccomp, it makes sense to | |
961 | * initialize that subset using ptrace_get_syscall_info_entry(). | |
962 | * This can be reconsidered in the future if these structures | |
963 | * diverge significantly enough. | |
964 | */ | |
965 | ptrace_get_syscall_info_entry(child, regs, info); | |
966 | info->op = PTRACE_SYSCALL_INFO_SECCOMP; | |
967 | info->seccomp.ret_data = child->ptrace_message; | |
968 | ||
969 | /* ret_data is the last field in struct ptrace_syscall_info.seccomp */ | |
970 | return offsetofend(struct ptrace_syscall_info, seccomp.ret_data); | |
971 | } | |
972 | ||
973 | static unsigned long | |
974 | ptrace_get_syscall_info_exit(struct task_struct *child, struct pt_regs *regs, | |
975 | struct ptrace_syscall_info *info) | |
976 | { | |
977 | info->op = PTRACE_SYSCALL_INFO_EXIT; | |
978 | info->exit.rval = syscall_get_error(child, regs); | |
979 | info->exit.is_error = !!info->exit.rval; | |
980 | if (!info->exit.is_error) | |
981 | info->exit.rval = syscall_get_return_value(child, regs); | |
982 | ||
983 | /* is_error is the last field in struct ptrace_syscall_info.exit */ | |
984 | return offsetofend(struct ptrace_syscall_info, exit.is_error); | |
985 | } | |
986 | ||
987 | static int | |
988 | ptrace_get_syscall_info(struct task_struct *child, unsigned long user_size, | |
989 | void __user *datavp) | |
990 | { | |
991 | struct pt_regs *regs = task_pt_regs(child); | |
992 | struct ptrace_syscall_info info = { | |
993 | .op = PTRACE_SYSCALL_INFO_NONE, | |
994 | .arch = syscall_get_arch(child), | |
995 | .instruction_pointer = instruction_pointer(regs), | |
996 | .stack_pointer = user_stack_pointer(regs), | |
997 | }; | |
998 | unsigned long actual_size = offsetof(struct ptrace_syscall_info, entry); | |
999 | unsigned long write_size; | |
1000 | ||
1001 | /* | |
1002 | * This does not need lock_task_sighand() to access | |
1003 | * child->last_siginfo because ptrace_freeze_traced() | |
1004 | * called earlier by ptrace_check_attach() ensures that | |
1005 | * the tracee cannot go away and clear its last_siginfo. | |
1006 | */ | |
1007 | switch (child->last_siginfo ? child->last_siginfo->si_code : 0) { | |
1008 | case SIGTRAP | 0x80: | |
1009 | switch (child->ptrace_message) { | |
1010 | case PTRACE_EVENTMSG_SYSCALL_ENTRY: | |
1011 | actual_size = ptrace_get_syscall_info_entry(child, regs, | |
1012 | &info); | |
1013 | break; | |
1014 | case PTRACE_EVENTMSG_SYSCALL_EXIT: | |
1015 | actual_size = ptrace_get_syscall_info_exit(child, regs, | |
1016 | &info); | |
1017 | break; | |
1018 | } | |
1019 | break; | |
1020 | case SIGTRAP | (PTRACE_EVENT_SECCOMP << 8): | |
1021 | actual_size = ptrace_get_syscall_info_seccomp(child, regs, | |
1022 | &info); | |
1023 | break; | |
1024 | } | |
1025 | ||
1026 | write_size = min(actual_size, user_size); | |
1027 | return copy_to_user(datavp, &info, write_size) ? -EFAULT : actual_size; | |
1028 | } | |
1029 | #endif /* CONFIG_HAVE_ARCH_TRACEHOOK */ | |
2225a122 | 1030 | |
1da177e4 | 1031 | int ptrace_request(struct task_struct *child, long request, |
4abf9869 | 1032 | unsigned long addr, unsigned long data) |
1da177e4 | 1033 | { |
fca26f26 | 1034 | bool seized = child->ptrace & PT_SEIZED; |
1da177e4 | 1035 | int ret = -EIO; |
ae7795bc | 1036 | kernel_siginfo_t siginfo, *si; |
9fed81dc NK |
1037 | void __user *datavp = (void __user *) data; |
1038 | unsigned long __user *datalp = datavp; | |
fca26f26 | 1039 | unsigned long flags; |
1da177e4 LT |
1040 | |
1041 | switch (request) { | |
16c3e389 RM |
1042 | case PTRACE_PEEKTEXT: |
1043 | case PTRACE_PEEKDATA: | |
1044 | return generic_ptrace_peekdata(child, addr, data); | |
1045 | case PTRACE_POKETEXT: | |
1046 | case PTRACE_POKEDATA: | |
1047 | return generic_ptrace_pokedata(child, addr, data); | |
1048 | ||
1da177e4 LT |
1049 | #ifdef PTRACE_OLDSETOPTIONS |
1050 | case PTRACE_OLDSETOPTIONS: | |
1051 | #endif | |
1052 | case PTRACE_SETOPTIONS: | |
1053 | ret = ptrace_setoptions(child, data); | |
1054 | break; | |
1055 | case PTRACE_GETEVENTMSG: | |
9fed81dc | 1056 | ret = put_user(child->ptrace_message, datalp); |
1da177e4 | 1057 | break; |
e16b2781 | 1058 | |
84c751bd AV |
1059 | case PTRACE_PEEKSIGINFO: |
1060 | ret = ptrace_peek_siginfo(child, addr, data); | |
1061 | break; | |
1062 | ||
1da177e4 | 1063 | case PTRACE_GETSIGINFO: |
e16b2781 RM |
1064 | ret = ptrace_getsiginfo(child, &siginfo); |
1065 | if (!ret) | |
9fed81dc | 1066 | ret = copy_siginfo_to_user(datavp, &siginfo); |
1da177e4 | 1067 | break; |
e16b2781 | 1068 | |
1da177e4 | 1069 | case PTRACE_SETSIGINFO: |
4cd2e0e7 EB |
1070 | ret = copy_siginfo_from_user(&siginfo, datavp); |
1071 | if (!ret) | |
e16b2781 | 1072 | ret = ptrace_setsiginfo(child, &siginfo); |
1da177e4 | 1073 | break; |
e16b2781 | 1074 | |
fcfc2aa0 AV |
1075 | case PTRACE_GETSIGMASK: { |
1076 | sigset_t *mask; | |
1077 | ||
29000cae AV |
1078 | if (addr != sizeof(sigset_t)) { |
1079 | ret = -EINVAL; | |
1080 | break; | |
1081 | } | |
1082 | ||
fcfc2aa0 AV |
1083 | if (test_tsk_restore_sigmask(child)) |
1084 | mask = &child->saved_sigmask; | |
1085 | else | |
1086 | mask = &child->blocked; | |
1087 | ||
1088 | if (copy_to_user(datavp, mask, sizeof(sigset_t))) | |
29000cae AV |
1089 | ret = -EFAULT; |
1090 | else | |
1091 | ret = 0; | |
1092 | ||
1093 | break; | |
fcfc2aa0 | 1094 | } |
29000cae AV |
1095 | |
1096 | case PTRACE_SETSIGMASK: { | |
1097 | sigset_t new_set; | |
1098 | ||
1099 | if (addr != sizeof(sigset_t)) { | |
1100 | ret = -EINVAL; | |
1101 | break; | |
1102 | } | |
1103 | ||
1104 | if (copy_from_user(&new_set, datavp, sizeof(sigset_t))) { | |
1105 | ret = -EFAULT; | |
1106 | break; | |
1107 | } | |
1108 | ||
1109 | sigdelsetmask(&new_set, sigmask(SIGKILL)|sigmask(SIGSTOP)); | |
1110 | ||
1111 | /* | |
1112 | * Every thread does recalc_sigpending() after resume, so | |
1113 | * retarget_shared_pending() and recalc_sigpending() are not | |
1114 | * called here. | |
1115 | */ | |
1116 | spin_lock_irq(&child->sighand->siglock); | |
1117 | child->blocked = new_set; | |
1118 | spin_unlock_irq(&child->sighand->siglock); | |
1119 | ||
fcfc2aa0 AV |
1120 | clear_tsk_restore_sigmask(child); |
1121 | ||
29000cae AV |
1122 | ret = 0; |
1123 | break; | |
1124 | } | |
1125 | ||
fca26f26 TH |
1126 | case PTRACE_INTERRUPT: |
1127 | /* | |
1128 | * Stop tracee without any side-effect on signal or job | |
1129 | * control. At least one trap is guaranteed to happen | |
1130 | * after this request. If @child is already trapped, the | |
1131 | * current trap is not disturbed and another trap will | |
1132 | * happen after the current trap is ended with PTRACE_CONT. | |
1133 | * | |
1134 | * The actual trap might not be PTRACE_EVENT_STOP trap but | |
1135 | * the pending condition is cleared regardless. | |
1136 | */ | |
1137 | if (unlikely(!seized || !lock_task_sighand(child, &flags))) | |
1138 | break; | |
1139 | ||
544b2c91 TH |
1140 | /* |
1141 | * INTERRUPT doesn't disturb existing trap sans one | |
1142 | * exception. If ptracer issued LISTEN for the current | |
1143 | * STOP, this INTERRUPT should clear LISTEN and re-trap | |
1144 | * tracee into STOP. | |
1145 | */ | |
fca26f26 | 1146 | if (likely(task_set_jobctl_pending(child, JOBCTL_TRAP_STOP))) |
910ffdb1 | 1147 | ptrace_signal_wake_up(child, child->jobctl & JOBCTL_LISTENING); |
544b2c91 TH |
1148 | |
1149 | unlock_task_sighand(child, &flags); | |
1150 | ret = 0; | |
1151 | break; | |
1152 | ||
1153 | case PTRACE_LISTEN: | |
1154 | /* | |
1155 | * Listen for events. Tracee must be in STOP. It's not | |
1156 | * resumed per-se but is not considered to be in TRACED by | |
1157 | * wait(2) or ptrace(2). If an async event (e.g. group | |
1158 | * stop state change) happens, tracee will enter STOP trap | |
1159 | * again. Alternatively, ptracer can issue INTERRUPT to | |
1160 | * finish listening and re-trap tracee into STOP. | |
1161 | */ | |
1162 | if (unlikely(!seized || !lock_task_sighand(child, &flags))) | |
1163 | break; | |
1164 | ||
1165 | si = child->last_siginfo; | |
f9d81f61 ON |
1166 | if (likely(si && (si->si_code >> 8) == PTRACE_EVENT_STOP)) { |
1167 | child->jobctl |= JOBCTL_LISTENING; | |
1168 | /* | |
1169 | * If NOTIFY is set, it means event happened between | |
1170 | * start of this trap and now. Trigger re-trap. | |
1171 | */ | |
1172 | if (child->jobctl & JOBCTL_TRAP_NOTIFY) | |
910ffdb1 | 1173 | ptrace_signal_wake_up(child, true); |
f9d81f61 ON |
1174 | ret = 0; |
1175 | } | |
fca26f26 | 1176 | unlock_task_sighand(child, &flags); |
fca26f26 TH |
1177 | break; |
1178 | ||
1bcf5482 AD |
1179 | case PTRACE_DETACH: /* detach a process that was attached. */ |
1180 | ret = ptrace_detach(child, data); | |
1181 | break; | |
36df29d7 | 1182 | |
9c1a1259 MF |
1183 | #ifdef CONFIG_BINFMT_ELF_FDPIC |
1184 | case PTRACE_GETFDPIC: { | |
e0129ef9 | 1185 | struct mm_struct *mm = get_task_mm(child); |
9c1a1259 MF |
1186 | unsigned long tmp = 0; |
1187 | ||
e0129ef9 ON |
1188 | ret = -ESRCH; |
1189 | if (!mm) | |
1190 | break; | |
1191 | ||
9c1a1259 MF |
1192 | switch (addr) { |
1193 | case PTRACE_GETFDPIC_EXEC: | |
e0129ef9 | 1194 | tmp = mm->context.exec_fdpic_loadmap; |
9c1a1259 MF |
1195 | break; |
1196 | case PTRACE_GETFDPIC_INTERP: | |
e0129ef9 | 1197 | tmp = mm->context.interp_fdpic_loadmap; |
9c1a1259 MF |
1198 | break; |
1199 | default: | |
1200 | break; | |
1201 | } | |
e0129ef9 | 1202 | mmput(mm); |
9c1a1259 | 1203 | |
9fed81dc | 1204 | ret = put_user(tmp, datalp); |
9c1a1259 MF |
1205 | break; |
1206 | } | |
1207 | #endif | |
1208 | ||
36df29d7 | 1209 | case PTRACE_SINGLESTEP: |
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: | |
6a2d90ba EB |
1222 | send_sig_info(SIGKILL, SEND_SIG_NOINFO, child); |
1223 | return 0; | |
36df29d7 | 1224 | |
2225a122 SS |
1225 | #ifdef CONFIG_HAVE_ARCH_TRACEHOOK |
1226 | case PTRACE_GETREGSET: | |
29000cae | 1227 | case PTRACE_SETREGSET: { |
2225a122 | 1228 | struct iovec kiov; |
9fed81dc | 1229 | struct iovec __user *uiov = datavp; |
2225a122 | 1230 | |
96d4f267 | 1231 | if (!access_ok(uiov, sizeof(*uiov))) |
2225a122 SS |
1232 | return -EFAULT; |
1233 | ||
1234 | if (__get_user(kiov.iov_base, &uiov->iov_base) || | |
1235 | __get_user(kiov.iov_len, &uiov->iov_len)) | |
1236 | return -EFAULT; | |
1237 | ||
1238 | ret = ptrace_regset(child, request, addr, &kiov); | |
1239 | if (!ret) | |
1240 | ret = __put_user(kiov.iov_len, &uiov->iov_len); | |
1241 | break; | |
1242 | } | |
201766a2 EK |
1243 | |
1244 | case PTRACE_GET_SYSCALL_INFO: | |
1245 | ret = ptrace_get_syscall_info(child, addr, datavp); | |
1246 | break; | |
2225a122 | 1247 | #endif |
f8e529ed TA |
1248 | |
1249 | case PTRACE_SECCOMP_GET_FILTER: | |
1250 | ret = seccomp_get_filter(child, addr, datavp); | |
1251 | break; | |
1252 | ||
26500475 TA |
1253 | case PTRACE_SECCOMP_GET_METADATA: |
1254 | ret = seccomp_get_metadata(child, addr, datavp); | |
1255 | break; | |
1256 | ||
90f093fa PF |
1257 | #ifdef CONFIG_RSEQ |
1258 | case PTRACE_GET_RSEQ_CONFIGURATION: | |
1259 | ret = ptrace_get_rseq_configuration(child, addr, datavp); | |
1260 | break; | |
1261 | #endif | |
1262 | ||
3f67987c GP |
1263 | case PTRACE_SET_SYSCALL_USER_DISPATCH_CONFIG: |
1264 | ret = syscall_user_dispatch_set_config(child, addr, datavp); | |
1265 | break; | |
1266 | ||
1267 | case PTRACE_GET_SYSCALL_USER_DISPATCH_CONFIG: | |
1268 | ret = syscall_user_dispatch_get_config(child, addr, datavp); | |
1269 | break; | |
1270 | ||
1da177e4 LT |
1271 | default: |
1272 | break; | |
1273 | } | |
1274 | ||
1275 | return ret; | |
1276 | } | |
481bed45 | 1277 | |
4abf9869 NK |
1278 | SYSCALL_DEFINE4(ptrace, long, request, long, pid, unsigned long, addr, |
1279 | unsigned long, data) | |
481bed45 CH |
1280 | { |
1281 | struct task_struct *child; | |
1282 | long ret; | |
1283 | ||
6b9c7ed8 CH |
1284 | if (request == PTRACE_TRACEME) { |
1285 | ret = ptrace_traceme(); | |
481bed45 | 1286 | goto out; |
6b9c7ed8 CH |
1287 | } |
1288 | ||
2ee08260 MR |
1289 | child = find_get_task_by_vpid(pid); |
1290 | if (!child) { | |
1291 | ret = -ESRCH; | |
6b9c7ed8 CH |
1292 | goto out; |
1293 | } | |
481bed45 | 1294 | |
3544d72a | 1295 | if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) { |
aa9147c9 | 1296 | ret = ptrace_attach(child, request, addr, data); |
005f18df | 1297 | goto out_put_task_struct; |
481bed45 CH |
1298 | } |
1299 | ||
fca26f26 TH |
1300 | ret = ptrace_check_attach(child, request == PTRACE_KILL || |
1301 | request == PTRACE_INTERRUPT); | |
481bed45 CH |
1302 | if (ret < 0) |
1303 | goto out_put_task_struct; | |
1304 | ||
1305 | ret = arch_ptrace(child, request, addr, data); | |
9899d11f ON |
1306 | if (ret || request != PTRACE_DETACH) |
1307 | ptrace_unfreeze_traced(child); | |
481bed45 CH |
1308 | |
1309 | out_put_task_struct: | |
1310 | put_task_struct(child); | |
1311 | out: | |
481bed45 CH |
1312 | return ret; |
1313 | } | |
76647323 | 1314 | |
4abf9869 NK |
1315 | int generic_ptrace_peekdata(struct task_struct *tsk, unsigned long addr, |
1316 | unsigned long data) | |
76647323 AD |
1317 | { |
1318 | unsigned long tmp; | |
1319 | int copied; | |
1320 | ||
84d77d3f | 1321 | copied = ptrace_access_vm(tsk, addr, &tmp, sizeof(tmp), FOLL_FORCE); |
76647323 AD |
1322 | if (copied != sizeof(tmp)) |
1323 | return -EIO; | |
1324 | return put_user(tmp, (unsigned long __user *)data); | |
1325 | } | |
f284ce72 | 1326 | |
4abf9869 NK |
1327 | int generic_ptrace_pokedata(struct task_struct *tsk, unsigned long addr, |
1328 | unsigned long data) | |
f284ce72 AD |
1329 | { |
1330 | int copied; | |
1331 | ||
84d77d3f | 1332 | copied = ptrace_access_vm(tsk, addr, &data, sizeof(data), |
f307ab6d | 1333 | FOLL_FORCE | FOLL_WRITE); |
f284ce72 AD |
1334 | return (copied == sizeof(data)) ? 0 : -EIO; |
1335 | } | |
032d82d9 | 1336 | |
96b8936a | 1337 | #if defined CONFIG_COMPAT |
032d82d9 RM |
1338 | |
1339 | int compat_ptrace_request(struct task_struct *child, compat_long_t request, | |
1340 | compat_ulong_t addr, compat_ulong_t data) | |
1341 | { | |
1342 | compat_ulong_t __user *datap = compat_ptr(data); | |
1343 | compat_ulong_t word; | |
ae7795bc | 1344 | kernel_siginfo_t siginfo; |
032d82d9 RM |
1345 | int ret; |
1346 | ||
1347 | switch (request) { | |
1348 | case PTRACE_PEEKTEXT: | |
1349 | case PTRACE_PEEKDATA: | |
84d77d3f | 1350 | ret = ptrace_access_vm(child, addr, &word, sizeof(word), |
f307ab6d | 1351 | FOLL_FORCE); |
032d82d9 RM |
1352 | if (ret != sizeof(word)) |
1353 | ret = -EIO; | |
1354 | else | |
1355 | ret = put_user(word, datap); | |
1356 | break; | |
1357 | ||
1358 | case PTRACE_POKETEXT: | |
1359 | case PTRACE_POKEDATA: | |
84d77d3f | 1360 | ret = ptrace_access_vm(child, addr, &data, sizeof(data), |
f307ab6d | 1361 | FOLL_FORCE | FOLL_WRITE); |
032d82d9 RM |
1362 | ret = (ret != sizeof(data) ? -EIO : 0); |
1363 | break; | |
1364 | ||
1365 | case PTRACE_GETEVENTMSG: | |
1366 | ret = put_user((compat_ulong_t) child->ptrace_message, datap); | |
1367 | break; | |
1368 | ||
e16b2781 RM |
1369 | case PTRACE_GETSIGINFO: |
1370 | ret = ptrace_getsiginfo(child, &siginfo); | |
1371 | if (!ret) | |
1372 | ret = copy_siginfo_to_user32( | |
1373 | (struct compat_siginfo __user *) datap, | |
1374 | &siginfo); | |
1375 | break; | |
1376 | ||
1377 | case PTRACE_SETSIGINFO: | |
4cd2e0e7 EB |
1378 | ret = copy_siginfo_from_user32( |
1379 | &siginfo, (struct compat_siginfo __user *) datap); | |
1380 | if (!ret) | |
e16b2781 RM |
1381 | ret = ptrace_setsiginfo(child, &siginfo); |
1382 | break; | |
2225a122 SS |
1383 | #ifdef CONFIG_HAVE_ARCH_TRACEHOOK |
1384 | case PTRACE_GETREGSET: | |
1385 | case PTRACE_SETREGSET: | |
1386 | { | |
1387 | struct iovec kiov; | |
1388 | struct compat_iovec __user *uiov = | |
1389 | (struct compat_iovec __user *) datap; | |
1390 | compat_uptr_t ptr; | |
1391 | compat_size_t len; | |
1392 | ||
96d4f267 | 1393 | if (!access_ok(uiov, sizeof(*uiov))) |
2225a122 SS |
1394 | return -EFAULT; |
1395 | ||
1396 | if (__get_user(ptr, &uiov->iov_base) || | |
1397 | __get_user(len, &uiov->iov_len)) | |
1398 | return -EFAULT; | |
1399 | ||
1400 | kiov.iov_base = compat_ptr(ptr); | |
1401 | kiov.iov_len = len; | |
1402 | ||
1403 | ret = ptrace_regset(child, request, addr, &kiov); | |
1404 | if (!ret) | |
1405 | ret = __put_user(kiov.iov_len, &uiov->iov_len); | |
1406 | break; | |
1407 | } | |
1408 | #endif | |
e16b2781 | 1409 | |
032d82d9 RM |
1410 | default: |
1411 | ret = ptrace_request(child, request, addr, data); | |
1412 | } | |
1413 | ||
1414 | return ret; | |
1415 | } | |
c269f196 | 1416 | |
62a6fa97 HC |
1417 | COMPAT_SYSCALL_DEFINE4(ptrace, compat_long_t, request, compat_long_t, pid, |
1418 | compat_long_t, addr, compat_long_t, data) | |
c269f196 RM |
1419 | { |
1420 | struct task_struct *child; | |
1421 | long ret; | |
1422 | ||
c269f196 RM |
1423 | if (request == PTRACE_TRACEME) { |
1424 | ret = ptrace_traceme(); | |
1425 | goto out; | |
1426 | } | |
1427 | ||
2ee08260 MR |
1428 | child = find_get_task_by_vpid(pid); |
1429 | if (!child) { | |
1430 | ret = -ESRCH; | |
c269f196 RM |
1431 | goto out; |
1432 | } | |
1433 | ||
3544d72a | 1434 | if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) { |
aa9147c9 | 1435 | ret = ptrace_attach(child, request, addr, data); |
c269f196 RM |
1436 | goto out_put_task_struct; |
1437 | } | |
1438 | ||
fca26f26 TH |
1439 | ret = ptrace_check_attach(child, request == PTRACE_KILL || |
1440 | request == PTRACE_INTERRUPT); | |
9899d11f | 1441 | if (!ret) { |
c269f196 | 1442 | ret = compat_arch_ptrace(child, request, addr, data); |
9899d11f ON |
1443 | if (ret || request != PTRACE_DETACH) |
1444 | ptrace_unfreeze_traced(child); | |
1445 | } | |
c269f196 RM |
1446 | |
1447 | out_put_task_struct: | |
1448 | put_task_struct(child); | |
1449 | out: | |
c269f196 RM |
1450 | return ret; |
1451 | } | |
96b8936a | 1452 | #endif /* CONFIG_COMPAT */ |