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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> |
1da177e4 | 34 | |
201766a2 EK |
35 | #include <asm/syscall.h> /* for syscall_get_* */ |
36 | ||
84d77d3f EB |
37 | /* |
38 | * Access another process' address space via ptrace. | |
39 | * Source/target buffer must be kernel space, | |
40 | * Do not walk the page table directly, use get_user_pages | |
41 | */ | |
42 | int ptrace_access_vm(struct task_struct *tsk, unsigned long addr, | |
43 | void *buf, int len, unsigned int gup_flags) | |
44 | { | |
45 | struct mm_struct *mm; | |
46 | int ret; | |
47 | ||
48 | mm = get_task_mm(tsk); | |
49 | if (!mm) | |
50 | return 0; | |
51 | ||
52 | if (!tsk->ptrace || | |
53 | (current != tsk->parent) || | |
54 | ((get_dumpable(mm) != SUID_DUMP_USER) && | |
55 | !ptracer_capable(tsk, mm->user_ns))) { | |
56 | mmput(mm); | |
57 | return 0; | |
58 | } | |
59 | ||
60 | ret = __access_remote_vm(tsk, mm, addr, buf, len, gup_flags); | |
61 | mmput(mm); | |
62 | ||
63 | return ret; | |
64 | } | |
65 | ||
bf53de90 | 66 | |
c70d9d80 EB |
67 | void __ptrace_link(struct task_struct *child, struct task_struct *new_parent, |
68 | const struct cred *ptracer_cred) | |
69 | { | |
70 | BUG_ON(!list_empty(&child->ptrace_entry)); | |
71 | list_add(&child->ptrace_entry, &new_parent->ptraced); | |
72 | child->parent = new_parent; | |
73 | child->ptracer_cred = get_cred(ptracer_cred); | |
74 | } | |
75 | ||
1da177e4 LT |
76 | /* |
77 | * ptrace a task: make the debugger its new parent and | |
78 | * move it to the ptrace list. | |
79 | * | |
80 | * Must be called with the tasklist lock write-held. | |
81 | */ | |
c70d9d80 | 82 | static void ptrace_link(struct task_struct *child, struct task_struct *new_parent) |
1da177e4 | 83 | { |
6994eefb | 84 | __ptrace_link(child, new_parent, current_cred()); |
1da177e4 | 85 | } |
3a709703 | 86 | |
e3bd058f TH |
87 | /** |
88 | * __ptrace_unlink - unlink ptracee and restore its execution state | |
89 | * @child: ptracee to be unlinked | |
1da177e4 | 90 | * |
0e9f0a4a TH |
91 | * Remove @child from the ptrace list, move it back to the original parent, |
92 | * and restore the execution state so that it conforms to the group stop | |
93 | * state. | |
94 | * | |
95 | * Unlinking can happen via two paths - explicit PTRACE_DETACH or ptracer | |
96 | * exiting. For PTRACE_DETACH, unless the ptracee has been killed between | |
97 | * ptrace_check_attach() and here, it's guaranteed to be in TASK_TRACED. | |
98 | * If the ptracer is exiting, the ptracee can be in any state. | |
99 | * | |
100 | * After detach, the ptracee should be in a state which conforms to the | |
101 | * group stop. If the group is stopped or in the process of stopping, the | |
102 | * ptracee should be put into TASK_STOPPED; otherwise, it should be woken | |
103 | * up from TASK_TRACED. | |
104 | * | |
105 | * If the ptracee is in TASK_TRACED and needs to be moved to TASK_STOPPED, | |
106 | * it goes through TRACED -> RUNNING -> STOPPED transition which is similar | |
107 | * to but in the opposite direction of what happens while attaching to a | |
108 | * stopped task. However, in this direction, the intermediate RUNNING | |
109 | * state is not hidden even from the current ptracer and if it immediately | |
110 | * re-attaches and performs a WNOHANG wait(2), it may fail. | |
e3bd058f TH |
111 | * |
112 | * CONTEXT: | |
113 | * write_lock_irq(tasklist_lock) | |
1da177e4 | 114 | */ |
36c8b586 | 115 | void __ptrace_unlink(struct task_struct *child) |
1da177e4 | 116 | { |
64b875f7 | 117 | const struct cred *old_cred; |
5ecfbae0 ON |
118 | BUG_ON(!child->ptrace); |
119 | ||
0a5bf409 | 120 | clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); |
15532fd6 SH |
121 | #ifdef TIF_SYSCALL_EMU |
122 | clear_tsk_thread_flag(child, TIF_SYSCALL_EMU); | |
123 | #endif | |
0a5bf409 | 124 | |
f470021a RM |
125 | child->parent = child->real_parent; |
126 | list_del_init(&child->ptrace_entry); | |
64b875f7 EB |
127 | old_cred = child->ptracer_cred; |
128 | child->ptracer_cred = NULL; | |
129 | put_cred(old_cred); | |
1da177e4 | 130 | |
1da177e4 | 131 | spin_lock(&child->sighand->siglock); |
1333ab03 | 132 | child->ptrace = 0; |
73ddff2b TH |
133 | /* |
134 | * Clear all pending traps and TRAPPING. TRAPPING should be | |
135 | * cleared regardless of JOBCTL_STOP_PENDING. Do it explicitly. | |
136 | */ | |
137 | task_clear_jobctl_pending(child, JOBCTL_TRAP_MASK); | |
138 | task_clear_jobctl_trapping(child); | |
139 | ||
0e9f0a4a | 140 | /* |
a8f072c1 | 141 | * Reinstate JOBCTL_STOP_PENDING if group stop is in effect and |
0e9f0a4a TH |
142 | * @child isn't dead. |
143 | */ | |
144 | if (!(child->flags & PF_EXITING) && | |
145 | (child->signal->flags & SIGNAL_STOP_STOPPED || | |
8a88951b | 146 | child->signal->group_stop_count)) { |
a8f072c1 | 147 | child->jobctl |= JOBCTL_STOP_PENDING; |
0e9f0a4a | 148 | |
8a88951b ON |
149 | /* |
150 | * This is only possible if this thread was cloned by the | |
151 | * traced task running in the stopped group, set the signal | |
152 | * for the future reports. | |
153 | * FIXME: we should change ptrace_init_task() to handle this | |
154 | * case. | |
155 | */ | |
156 | if (!(child->jobctl & JOBCTL_STOP_SIGMASK)) | |
157 | child->jobctl |= SIGSTOP; | |
158 | } | |
159 | ||
0e9f0a4a TH |
160 | /* |
161 | * If transition to TASK_STOPPED is pending or in TASK_TRACED, kick | |
162 | * @child in the butt. Note that @resume should be used iff @child | |
163 | * is in TASK_TRACED; otherwise, we might unduly disrupt | |
164 | * TASK_KILLABLE sleeps. | |
165 | */ | |
a8f072c1 | 166 | if (child->jobctl & JOBCTL_STOP_PENDING || task_is_traced(child)) |
910ffdb1 | 167 | ptrace_signal_wake_up(child, true); |
0e9f0a4a | 168 | |
1da177e4 | 169 | spin_unlock(&child->sighand->siglock); |
1da177e4 LT |
170 | } |
171 | ||
9899d11f ON |
172 | /* Ensure that nothing can wake it up, even SIGKILL */ |
173 | static bool ptrace_freeze_traced(struct task_struct *task) | |
174 | { | |
175 | bool ret = false; | |
176 | ||
177 | /* Lockless, nobody but us can set this flag */ | |
178 | if (task->jobctl & JOBCTL_LISTENING) | |
179 | return ret; | |
180 | ||
181 | spin_lock_irq(&task->sighand->siglock); | |
182 | if (task_is_traced(task) && !__fatal_signal_pending(task)) { | |
183 | task->state = __TASK_TRACED; | |
184 | ret = true; | |
185 | } | |
186 | spin_unlock_irq(&task->sighand->siglock); | |
187 | ||
188 | return ret; | |
189 | } | |
190 | ||
191 | static void ptrace_unfreeze_traced(struct task_struct *task) | |
192 | { | |
193 | if (task->state != __TASK_TRACED) | |
194 | return; | |
195 | ||
196 | WARN_ON(!task->ptrace || task->parent != current); | |
197 | ||
5402e97a | 198 | /* |
199 | * PTRACE_LISTEN can allow ptrace_trap_notify to wake us up remotely. | |
200 | * Recheck state under the lock to close this race. | |
201 | */ | |
9899d11f | 202 | spin_lock_irq(&task->sighand->siglock); |
5402e97a | 203 | if (task->state == __TASK_TRACED) { |
204 | if (__fatal_signal_pending(task)) | |
205 | wake_up_state(task, __TASK_TRACED); | |
206 | else | |
207 | task->state = TASK_TRACED; | |
208 | } | |
9899d11f ON |
209 | spin_unlock_irq(&task->sighand->siglock); |
210 | } | |
211 | ||
755e276b TH |
212 | /** |
213 | * ptrace_check_attach - check whether ptracee is ready for ptrace operation | |
214 | * @child: ptracee to check for | |
215 | * @ignore_state: don't check whether @child is currently %TASK_TRACED | |
216 | * | |
217 | * Check whether @child is being ptraced by %current and ready for further | |
218 | * ptrace operations. If @ignore_state is %false, @child also should be in | |
219 | * %TASK_TRACED state and on return the child is guaranteed to be traced | |
220 | * and not executing. If @ignore_state is %true, @child can be in any | |
221 | * state. | |
222 | * | |
223 | * CONTEXT: | |
224 | * Grabs and releases tasklist_lock and @child->sighand->siglock. | |
225 | * | |
226 | * RETURNS: | |
227 | * 0 on success, -ESRCH if %child is not ready. | |
1da177e4 | 228 | */ |
edea0d03 | 229 | static int ptrace_check_attach(struct task_struct *child, bool ignore_state) |
1da177e4 LT |
230 | { |
231 | int ret = -ESRCH; | |
232 | ||
233 | /* | |
234 | * We take the read lock around doing both checks to close a | |
235 | * possible race where someone else was tracing our child and | |
236 | * detached between these two checks. After this locked check, | |
237 | * we are sure that this is our traced child and that can only | |
238 | * be changed by us so it's not changing right after this. | |
239 | */ | |
240 | read_lock(&tasklist_lock); | |
9899d11f ON |
241 | if (child->ptrace && child->parent == current) { |
242 | WARN_ON(child->state == __TASK_TRACED); | |
c0c0b649 ON |
243 | /* |
244 | * child->sighand can't be NULL, release_task() | |
245 | * does ptrace_unlink() before __exit_signal(). | |
246 | */ | |
9899d11f | 247 | if (ignore_state || ptrace_freeze_traced(child)) |
321fb561 | 248 | ret = 0; |
1da177e4 LT |
249 | } |
250 | read_unlock(&tasklist_lock); | |
251 | ||
9899d11f ON |
252 | if (!ret && !ignore_state) { |
253 | if (!wait_task_inactive(child, __TASK_TRACED)) { | |
254 | /* | |
255 | * This can only happen if may_ptrace_stop() fails and | |
256 | * ptrace_stop() changes ->state back to TASK_RUNNING, | |
257 | * so we should not worry about leaking __TASK_TRACED. | |
258 | */ | |
259 | WARN_ON(child->state == __TASK_TRACED); | |
260 | ret = -ESRCH; | |
261 | } | |
262 | } | |
1da177e4 | 263 | |
1da177e4 LT |
264 | return ret; |
265 | } | |
266 | ||
6b3ad664 CB |
267 | static bool ptrace_has_cap(const struct cred *cred, struct user_namespace *ns, |
268 | unsigned int mode) | |
69f594a3 | 269 | { |
6b3ad664 CB |
270 | int ret; |
271 | ||
69f594a3 | 272 | if (mode & PTRACE_MODE_NOAUDIT) |
6b3ad664 | 273 | ret = security_capable(cred, ns, CAP_SYS_PTRACE, CAP_OPT_NOAUDIT); |
69f594a3 | 274 | else |
6b3ad664 CB |
275 | ret = security_capable(cred, ns, CAP_SYS_PTRACE, CAP_OPT_NONE); |
276 | ||
277 | return ret == 0; | |
69f594a3 EP |
278 | } |
279 | ||
9f99798f TH |
280 | /* Returns 0 on success, -errno on denial. */ |
281 | static int __ptrace_may_access(struct task_struct *task, unsigned int mode) | |
ab8d11be | 282 | { |
c69e8d9c | 283 | const struct cred *cred = current_cred(), *tcred; |
bfedb589 | 284 | struct mm_struct *mm; |
caaee623 JH |
285 | kuid_t caller_uid; |
286 | kgid_t caller_gid; | |
287 | ||
288 | if (!(mode & PTRACE_MODE_FSCREDS) == !(mode & PTRACE_MODE_REALCREDS)) { | |
289 | WARN(1, "denying ptrace access check without PTRACE_MODE_*CREDS\n"); | |
290 | return -EPERM; | |
291 | } | |
b6dff3ec | 292 | |
df26c40e EB |
293 | /* May we inspect the given task? |
294 | * This check is used both for attaching with ptrace | |
295 | * and for allowing access to sensitive information in /proc. | |
296 | * | |
297 | * ptrace_attach denies several cases that /proc allows | |
298 | * because setting up the necessary parent/child relationship | |
299 | * or halting the specified task is impossible. | |
300 | */ | |
caaee623 | 301 | |
df26c40e | 302 | /* Don't let security modules deny introspection */ |
73af963f | 303 | if (same_thread_group(task, current)) |
df26c40e | 304 | return 0; |
c69e8d9c | 305 | rcu_read_lock(); |
caaee623 JH |
306 | if (mode & PTRACE_MODE_FSCREDS) { |
307 | caller_uid = cred->fsuid; | |
308 | caller_gid = cred->fsgid; | |
309 | } else { | |
310 | /* | |
311 | * Using the euid would make more sense here, but something | |
312 | * in userland might rely on the old behavior, and this | |
313 | * shouldn't be a security problem since | |
314 | * PTRACE_MODE_REALCREDS implies that the caller explicitly | |
315 | * used a syscall that requests access to another process | |
316 | * (and not a filesystem syscall to procfs). | |
317 | */ | |
318 | caller_uid = cred->uid; | |
319 | caller_gid = cred->gid; | |
320 | } | |
c69e8d9c | 321 | tcred = __task_cred(task); |
caaee623 JH |
322 | if (uid_eq(caller_uid, tcred->euid) && |
323 | uid_eq(caller_uid, tcred->suid) && | |
324 | uid_eq(caller_uid, tcred->uid) && | |
325 | gid_eq(caller_gid, tcred->egid) && | |
326 | gid_eq(caller_gid, tcred->sgid) && | |
327 | gid_eq(caller_gid, tcred->gid)) | |
8409cca7 | 328 | goto ok; |
6b3ad664 | 329 | if (ptrace_has_cap(cred, tcred->user_ns, mode)) |
8409cca7 SH |
330 | goto ok; |
331 | rcu_read_unlock(); | |
332 | return -EPERM; | |
333 | ok: | |
c69e8d9c | 334 | rcu_read_unlock(); |
f6581f5b JH |
335 | /* |
336 | * If a task drops privileges and becomes nondumpable (through a syscall | |
337 | * like setresuid()) while we are trying to access it, we must ensure | |
338 | * that the dumpability is read after the credentials; otherwise, | |
339 | * we may be able to attach to a task that we shouldn't be able to | |
340 | * attach to (as if the task had dropped privileges without becoming | |
341 | * nondumpable). | |
342 | * Pairs with a write barrier in commit_creds(). | |
343 | */ | |
344 | smp_rmb(); | |
bfedb589 EB |
345 | mm = task->mm; |
346 | if (mm && | |
347 | ((get_dumpable(mm) != SUID_DUMP_USER) && | |
6b3ad664 | 348 | !ptrace_has_cap(cred, mm->user_ns, mode))) |
bfedb589 | 349 | return -EPERM; |
ab8d11be | 350 | |
9e48858f | 351 | return security_ptrace_access_check(task, mode); |
ab8d11be MS |
352 | } |
353 | ||
006ebb40 | 354 | bool ptrace_may_access(struct task_struct *task, unsigned int mode) |
ab8d11be MS |
355 | { |
356 | int err; | |
357 | task_lock(task); | |
006ebb40 | 358 | err = __ptrace_may_access(task, mode); |
ab8d11be | 359 | task_unlock(task); |
3a709703 | 360 | return !err; |
ab8d11be MS |
361 | } |
362 | ||
3544d72a | 363 | static int ptrace_attach(struct task_struct *task, long request, |
aa9147c9 | 364 | unsigned long addr, |
3544d72a | 365 | unsigned long flags) |
1da177e4 | 366 | { |
3544d72a | 367 | bool seize = (request == PTRACE_SEIZE); |
1da177e4 | 368 | int retval; |
f5b40e36 | 369 | |
3544d72a | 370 | retval = -EIO; |
aa9147c9 DV |
371 | if (seize) { |
372 | if (addr != 0) | |
373 | goto out; | |
aa9147c9 DV |
374 | if (flags & ~(unsigned long)PTRACE_O_MASK) |
375 | goto out; | |
376 | flags = PT_PTRACED | PT_SEIZED | (flags << PT_OPT_FLAG_SHIFT); | |
377 | } else { | |
378 | flags = PT_PTRACED; | |
379 | } | |
3544d72a | 380 | |
a5cb013d AV |
381 | audit_ptrace(task); |
382 | ||
1da177e4 | 383 | retval = -EPERM; |
b79b7ba9 ON |
384 | if (unlikely(task->flags & PF_KTHREAD)) |
385 | goto out; | |
bac0abd6 | 386 | if (same_thread_group(task, current)) |
f5b40e36 LT |
387 | goto out; |
388 | ||
f2f0b00a ON |
389 | /* |
390 | * Protect exec's credential calculations against our interference; | |
86b6c1f3 | 391 | * SUID, SGID and LSM creds get determined differently |
5e751e99 | 392 | * under ptrace. |
d84f4f99 | 393 | */ |
793285fc | 394 | retval = -ERESTARTNOINTR; |
9b1bf12d | 395 | if (mutex_lock_interruptible(&task->signal->cred_guard_mutex)) |
d84f4f99 | 396 | goto out; |
f5b40e36 | 397 | |
4b105cbb | 398 | task_lock(task); |
caaee623 | 399 | retval = __ptrace_may_access(task, PTRACE_MODE_ATTACH_REALCREDS); |
4b105cbb | 400 | task_unlock(task); |
1da177e4 | 401 | if (retval) |
4b105cbb | 402 | goto unlock_creds; |
1da177e4 | 403 | |
4b105cbb | 404 | write_lock_irq(&tasklist_lock); |
b79b7ba9 ON |
405 | retval = -EPERM; |
406 | if (unlikely(task->exit_state)) | |
4b105cbb | 407 | goto unlock_tasklist; |
f2f0b00a | 408 | if (task->ptrace) |
4b105cbb | 409 | goto unlock_tasklist; |
b79b7ba9 | 410 | |
3544d72a | 411 | if (seize) |
aa9147c9 | 412 | flags |= PT_SEIZED; |
aa9147c9 | 413 | task->ptrace = flags; |
1da177e4 | 414 | |
c70d9d80 | 415 | ptrace_link(task, current); |
3544d72a TH |
416 | |
417 | /* SEIZE doesn't trap tracee on attach */ | |
418 | if (!seize) | |
079b22dc | 419 | send_sig_info(SIGSTOP, SEND_SIG_PRIV, task); |
b79b7ba9 | 420 | |
d79fdd6d TH |
421 | spin_lock(&task->sighand->siglock); |
422 | ||
423 | /* | |
73ddff2b | 424 | * If the task is already STOPPED, set JOBCTL_TRAP_STOP and |
d79fdd6d TH |
425 | * TRAPPING, and kick it so that it transits to TRACED. TRAPPING |
426 | * will be cleared if the child completes the transition or any | |
427 | * event which clears the group stop states happens. We'll wait | |
428 | * for the transition to complete before returning from this | |
429 | * function. | |
430 | * | |
431 | * This hides STOPPED -> RUNNING -> TRACED transition from the | |
432 | * attaching thread but a different thread in the same group can | |
433 | * still observe the transient RUNNING state. IOW, if another | |
434 | * thread's WNOHANG wait(2) on the stopped tracee races against | |
435 | * ATTACH, the wait(2) may fail due to the transient RUNNING. | |
436 | * | |
437 | * The following task_is_stopped() test is safe as both transitions | |
438 | * in and out of STOPPED are protected by siglock. | |
439 | */ | |
7dd3db54 | 440 | if (task_is_stopped(task) && |
73ddff2b | 441 | task_set_jobctl_pending(task, JOBCTL_TRAP_STOP | JOBCTL_TRAPPING)) |
910ffdb1 | 442 | signal_wake_up_state(task, __TASK_STOPPED); |
d79fdd6d TH |
443 | |
444 | spin_unlock(&task->sighand->siglock); | |
445 | ||
b79b7ba9 | 446 | retval = 0; |
4b105cbb ON |
447 | unlock_tasklist: |
448 | write_unlock_irq(&tasklist_lock); | |
449 | unlock_creds: | |
9b1bf12d | 450 | mutex_unlock(&task->signal->cred_guard_mutex); |
f5b40e36 | 451 | out: |
f701e5b7 | 452 | if (!retval) { |
7c3b00e0 ON |
453 | /* |
454 | * We do not bother to change retval or clear JOBCTL_TRAPPING | |
455 | * if wait_on_bit() was interrupted by SIGKILL. The tracer will | |
456 | * not return to user-mode, it will exit and clear this bit in | |
457 | * __ptrace_unlink() if it wasn't already cleared by the tracee; | |
458 | * and until then nobody can ptrace this task. | |
459 | */ | |
460 | wait_on_bit(&task->jobctl, JOBCTL_TRAPPING_BIT, TASK_KILLABLE); | |
f701e5b7 VZ |
461 | proc_ptrace_connector(task, PTRACE_ATTACH); |
462 | } | |
463 | ||
1da177e4 LT |
464 | return retval; |
465 | } | |
466 | ||
f2f0b00a ON |
467 | /** |
468 | * ptrace_traceme -- helper for PTRACE_TRACEME | |
469 | * | |
470 | * Performs checks and sets PT_PTRACED. | |
471 | * Should be used by all ptrace implementations for PTRACE_TRACEME. | |
472 | */ | |
e3e89cc5 | 473 | static int ptrace_traceme(void) |
f2f0b00a ON |
474 | { |
475 | int ret = -EPERM; | |
476 | ||
4b105cbb ON |
477 | write_lock_irq(&tasklist_lock); |
478 | /* Are we already being traced? */ | |
f2f0b00a | 479 | if (!current->ptrace) { |
f2f0b00a | 480 | ret = security_ptrace_traceme(current->parent); |
f2f0b00a ON |
481 | /* |
482 | * Check PF_EXITING to ensure ->real_parent has not passed | |
483 | * exit_ptrace(). Otherwise we don't report the error but | |
484 | * pretend ->real_parent untraces us right after return. | |
485 | */ | |
486 | if (!ret && !(current->real_parent->flags & PF_EXITING)) { | |
487 | current->ptrace = PT_PTRACED; | |
c70d9d80 | 488 | ptrace_link(current, current->real_parent); |
f2f0b00a | 489 | } |
f2f0b00a | 490 | } |
4b105cbb ON |
491 | write_unlock_irq(&tasklist_lock); |
492 | ||
f2f0b00a ON |
493 | return ret; |
494 | } | |
495 | ||
39c626ae ON |
496 | /* |
497 | * Called with irqs disabled, returns true if childs should reap themselves. | |
498 | */ | |
499 | static int ignoring_children(struct sighand_struct *sigh) | |
500 | { | |
501 | int ret; | |
502 | spin_lock(&sigh->siglock); | |
503 | ret = (sigh->action[SIGCHLD-1].sa.sa_handler == SIG_IGN) || | |
504 | (sigh->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT); | |
505 | spin_unlock(&sigh->siglock); | |
506 | return ret; | |
507 | } | |
508 | ||
509 | /* | |
510 | * Called with tasklist_lock held for writing. | |
511 | * Unlink a traced task, and clean it up if it was a traced zombie. | |
512 | * Return true if it needs to be reaped with release_task(). | |
513 | * (We can't call release_task() here because we already hold tasklist_lock.) | |
514 | * | |
515 | * If it's a zombie, our attachedness prevented normal parent notification | |
516 | * or self-reaping. Do notification now if it would have happened earlier. | |
517 | * If it should reap itself, return true. | |
518 | * | |
a7f0765e ON |
519 | * If it's our own child, there is no notification to do. But if our normal |
520 | * children self-reap, then this child was prevented by ptrace and we must | |
521 | * reap it now, in that case we must also wake up sub-threads sleeping in | |
522 | * do_wait(). | |
39c626ae ON |
523 | */ |
524 | static bool __ptrace_detach(struct task_struct *tracer, struct task_struct *p) | |
525 | { | |
9843a1e9 ON |
526 | bool dead; |
527 | ||
39c626ae ON |
528 | __ptrace_unlink(p); |
529 | ||
9843a1e9 ON |
530 | if (p->exit_state != EXIT_ZOMBIE) |
531 | return false; | |
532 | ||
533 | dead = !thread_group_leader(p); | |
534 | ||
535 | if (!dead && thread_group_empty(p)) { | |
536 | if (!same_thread_group(p->real_parent, tracer)) | |
537 | dead = do_notify_parent(p, p->exit_signal); | |
538 | else if (ignoring_children(tracer->sighand)) { | |
539 | __wake_up_parent(p, tracer); | |
9843a1e9 | 540 | dead = true; |
39c626ae ON |
541 | } |
542 | } | |
9843a1e9 ON |
543 | /* Mark it as in the process of being reaped. */ |
544 | if (dead) | |
545 | p->exit_state = EXIT_DEAD; | |
546 | return dead; | |
39c626ae ON |
547 | } |
548 | ||
e3e89cc5 | 549 | static int ptrace_detach(struct task_struct *child, unsigned int data) |
1da177e4 | 550 | { |
7ed20e1a | 551 | if (!valid_signal(data)) |
5ecfbae0 | 552 | return -EIO; |
1da177e4 LT |
553 | |
554 | /* Architecture-specific hardware disable .. */ | |
555 | ptrace_disable(child); | |
556 | ||
95c3eb76 | 557 | write_lock_irq(&tasklist_lock); |
39c626ae | 558 | /* |
64a4096c ON |
559 | * We rely on ptrace_freeze_traced(). It can't be killed and |
560 | * untraced by another thread, it can't be a zombie. | |
39c626ae | 561 | */ |
64a4096c ON |
562 | WARN_ON(!child->ptrace || child->exit_state); |
563 | /* | |
564 | * tasklist_lock avoids the race with wait_task_stopped(), see | |
565 | * the comment in ptrace_resume(). | |
566 | */ | |
567 | child->exit_code = data; | |
568 | __ptrace_detach(current, child); | |
1da177e4 LT |
569 | write_unlock_irq(&tasklist_lock); |
570 | ||
f701e5b7 | 571 | proc_ptrace_connector(child, PTRACE_DETACH); |
4576145c | 572 | |
1da177e4 LT |
573 | return 0; |
574 | } | |
575 | ||
39c626ae | 576 | /* |
c7e49c14 | 577 | * Detach all tasks we were using ptrace on. Called with tasklist held |
7c8bd232 | 578 | * for writing. |
39c626ae | 579 | */ |
7c8bd232 | 580 | void exit_ptrace(struct task_struct *tracer, struct list_head *dead) |
39c626ae ON |
581 | { |
582 | struct task_struct *p, *n; | |
c7e49c14 | 583 | |
39c626ae | 584 | list_for_each_entry_safe(p, n, &tracer->ptraced, ptrace_entry) { |
992fb6e1 | 585 | if (unlikely(p->ptrace & PT_EXITKILL)) |
079b22dc | 586 | send_sig_info(SIGKILL, SEND_SIG_PRIV, p); |
992fb6e1 | 587 | |
39c626ae | 588 | if (__ptrace_detach(tracer, p)) |
7c8bd232 | 589 | list_add(&p->ptrace_entry, dead); |
39c626ae ON |
590 | } |
591 | } | |
592 | ||
1da177e4 LT |
593 | int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len) |
594 | { | |
595 | int copied = 0; | |
596 | ||
597 | while (len > 0) { | |
598 | char buf[128]; | |
599 | int this_len, retval; | |
600 | ||
601 | this_len = (len > sizeof(buf)) ? sizeof(buf) : len; | |
84d77d3f EB |
602 | retval = ptrace_access_vm(tsk, src, buf, this_len, FOLL_FORCE); |
603 | ||
1da177e4 LT |
604 | if (!retval) { |
605 | if (copied) | |
606 | break; | |
607 | return -EIO; | |
608 | } | |
609 | if (copy_to_user(dst, buf, retval)) | |
610 | return -EFAULT; | |
611 | copied += retval; | |
612 | src += retval; | |
613 | dst += retval; | |
3a709703 | 614 | len -= retval; |
1da177e4 LT |
615 | } |
616 | return copied; | |
617 | } | |
618 | ||
619 | int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len) | |
620 | { | |
621 | int copied = 0; | |
622 | ||
623 | while (len > 0) { | |
624 | char buf[128]; | |
625 | int this_len, retval; | |
626 | ||
627 | this_len = (len > sizeof(buf)) ? sizeof(buf) : len; | |
628 | if (copy_from_user(buf, src, this_len)) | |
629 | return -EFAULT; | |
84d77d3f | 630 | retval = ptrace_access_vm(tsk, dst, buf, this_len, |
f307ab6d | 631 | FOLL_FORCE | FOLL_WRITE); |
1da177e4 LT |
632 | if (!retval) { |
633 | if (copied) | |
634 | break; | |
635 | return -EIO; | |
636 | } | |
637 | copied += retval; | |
638 | src += retval; | |
639 | dst += retval; | |
3a709703 | 640 | len -= retval; |
1da177e4 LT |
641 | } |
642 | return copied; | |
643 | } | |
644 | ||
4abf9869 | 645 | static int ptrace_setoptions(struct task_struct *child, unsigned long data) |
1da177e4 | 646 | { |
86b6c1f3 DV |
647 | unsigned flags; |
648 | ||
8c5cf9e5 DV |
649 | if (data & ~(unsigned long)PTRACE_O_MASK) |
650 | return -EINVAL; | |
651 | ||
13c4a901 | 652 | if (unlikely(data & PTRACE_O_SUSPEND_SECCOMP)) { |
97f2645f MY |
653 | if (!IS_ENABLED(CONFIG_CHECKPOINT_RESTORE) || |
654 | !IS_ENABLED(CONFIG_SECCOMP)) | |
13c4a901 TA |
655 | return -EINVAL; |
656 | ||
657 | if (!capable(CAP_SYS_ADMIN)) | |
658 | return -EPERM; | |
659 | ||
660 | if (seccomp_mode(¤t->seccomp) != SECCOMP_MODE_DISABLED || | |
661 | current->ptrace & PT_SUSPEND_SECCOMP) | |
662 | return -EPERM; | |
663 | } | |
664 | ||
86b6c1f3 DV |
665 | /* Avoid intermediate state when all opts are cleared */ |
666 | flags = child->ptrace; | |
667 | flags &= ~(PTRACE_O_MASK << PT_OPT_FLAG_SHIFT); | |
668 | flags |= (data << PT_OPT_FLAG_SHIFT); | |
669 | child->ptrace = flags; | |
1da177e4 | 670 | |
8c5cf9e5 | 671 | return 0; |
1da177e4 LT |
672 | } |
673 | ||
ae7795bc | 674 | static int ptrace_getsiginfo(struct task_struct *child, kernel_siginfo_t *info) |
1da177e4 | 675 | { |
e4961254 | 676 | unsigned long flags; |
1da177e4 LT |
677 | int error = -ESRCH; |
678 | ||
e4961254 | 679 | if (lock_task_sighand(child, &flags)) { |
1da177e4 | 680 | error = -EINVAL; |
1da177e4 | 681 | if (likely(child->last_siginfo != NULL)) { |
0752d7bf | 682 | copy_siginfo(info, child->last_siginfo); |
1da177e4 LT |
683 | error = 0; |
684 | } | |
e4961254 | 685 | unlock_task_sighand(child, &flags); |
1da177e4 | 686 | } |
1da177e4 LT |
687 | return error; |
688 | } | |
689 | ||
ae7795bc | 690 | static int ptrace_setsiginfo(struct task_struct *child, const kernel_siginfo_t *info) |
1da177e4 | 691 | { |
e4961254 | 692 | unsigned long flags; |
1da177e4 LT |
693 | int error = -ESRCH; |
694 | ||
e4961254 | 695 | if (lock_task_sighand(child, &flags)) { |
1da177e4 | 696 | error = -EINVAL; |
1da177e4 | 697 | if (likely(child->last_siginfo != NULL)) { |
0752d7bf | 698 | copy_siginfo(child->last_siginfo, info); |
1da177e4 LT |
699 | error = 0; |
700 | } | |
e4961254 | 701 | unlock_task_sighand(child, &flags); |
1da177e4 | 702 | } |
1da177e4 LT |
703 | return error; |
704 | } | |
705 | ||
84c751bd AV |
706 | static int ptrace_peek_siginfo(struct task_struct *child, |
707 | unsigned long addr, | |
708 | unsigned long data) | |
709 | { | |
710 | struct ptrace_peeksiginfo_args arg; | |
711 | struct sigpending *pending; | |
712 | struct sigqueue *q; | |
713 | int ret, i; | |
714 | ||
715 | ret = copy_from_user(&arg, (void __user *) addr, | |
716 | sizeof(struct ptrace_peeksiginfo_args)); | |
717 | if (ret) | |
718 | return -EFAULT; | |
719 | ||
720 | if (arg.flags & ~PTRACE_PEEKSIGINFO_SHARED) | |
721 | return -EINVAL; /* unknown flags */ | |
722 | ||
723 | if (arg.nr < 0) | |
724 | return -EINVAL; | |
725 | ||
f6e2aa91 EB |
726 | /* Ensure arg.off fits in an unsigned long */ |
727 | if (arg.off > ULONG_MAX) | |
728 | return 0; | |
729 | ||
84c751bd AV |
730 | if (arg.flags & PTRACE_PEEKSIGINFO_SHARED) |
731 | pending = &child->signal->shared_pending; | |
732 | else | |
733 | pending = &child->pending; | |
734 | ||
735 | for (i = 0; i < arg.nr; ) { | |
ae7795bc | 736 | kernel_siginfo_t info; |
f6e2aa91 EB |
737 | unsigned long off = arg.off + i; |
738 | bool found = false; | |
84c751bd AV |
739 | |
740 | spin_lock_irq(&child->sighand->siglock); | |
741 | list_for_each_entry(q, &pending->list, list) { | |
742 | if (!off--) { | |
f6e2aa91 | 743 | found = true; |
84c751bd AV |
744 | copy_siginfo(&info, &q->info); |
745 | break; | |
746 | } | |
747 | } | |
748 | spin_unlock_irq(&child->sighand->siglock); | |
749 | ||
f6e2aa91 | 750 | if (!found) /* beyond the end of the list */ |
84c751bd AV |
751 | break; |
752 | ||
753 | #ifdef CONFIG_COMPAT | |
5c465217 | 754 | if (unlikely(in_compat_syscall())) { |
84c751bd AV |
755 | compat_siginfo_t __user *uinfo = compat_ptr(data); |
756 | ||
cc731525 | 757 | if (copy_siginfo_to_user32(uinfo, &info)) { |
706b23bd MD |
758 | ret = -EFAULT; |
759 | break; | |
760 | } | |
761 | ||
84c751bd AV |
762 | } else |
763 | #endif | |
764 | { | |
765 | siginfo_t __user *uinfo = (siginfo_t __user *) data; | |
766 | ||
cc731525 | 767 | if (copy_siginfo_to_user(uinfo, &info)) { |
706b23bd MD |
768 | ret = -EFAULT; |
769 | break; | |
770 | } | |
84c751bd AV |
771 | } |
772 | ||
773 | data += sizeof(siginfo_t); | |
774 | i++; | |
775 | ||
776 | if (signal_pending(current)) | |
777 | break; | |
778 | ||
779 | cond_resched(); | |
780 | } | |
781 | ||
782 | if (i > 0) | |
783 | return i; | |
784 | ||
785 | return ret; | |
786 | } | |
36df29d7 RM |
787 | |
788 | #ifdef PTRACE_SINGLESTEP | |
789 | #define is_singlestep(request) ((request) == PTRACE_SINGLESTEP) | |
790 | #else | |
791 | #define is_singlestep(request) 0 | |
792 | #endif | |
793 | ||
5b88abbf RM |
794 | #ifdef PTRACE_SINGLEBLOCK |
795 | #define is_singleblock(request) ((request) == PTRACE_SINGLEBLOCK) | |
796 | #else | |
797 | #define is_singleblock(request) 0 | |
798 | #endif | |
799 | ||
36df29d7 RM |
800 | #ifdef PTRACE_SYSEMU |
801 | #define is_sysemu_singlestep(request) ((request) == PTRACE_SYSEMU_SINGLESTEP) | |
802 | #else | |
803 | #define is_sysemu_singlestep(request) 0 | |
804 | #endif | |
805 | ||
4abf9869 NK |
806 | static int ptrace_resume(struct task_struct *child, long request, |
807 | unsigned long data) | |
36df29d7 | 808 | { |
b72c1869 ON |
809 | bool need_siglock; |
810 | ||
36df29d7 RM |
811 | if (!valid_signal(data)) |
812 | return -EIO; | |
813 | ||
814 | if (request == PTRACE_SYSCALL) | |
815 | set_tsk_thread_flag(child, TIF_SYSCALL_TRACE); | |
816 | else | |
817 | clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); | |
818 | ||
819 | #ifdef TIF_SYSCALL_EMU | |
820 | if (request == PTRACE_SYSEMU || request == PTRACE_SYSEMU_SINGLESTEP) | |
821 | set_tsk_thread_flag(child, TIF_SYSCALL_EMU); | |
822 | else | |
823 | clear_tsk_thread_flag(child, TIF_SYSCALL_EMU); | |
824 | #endif | |
825 | ||
5b88abbf RM |
826 | if (is_singleblock(request)) { |
827 | if (unlikely(!arch_has_block_step())) | |
828 | return -EIO; | |
829 | user_enable_block_step(child); | |
830 | } else if (is_singlestep(request) || is_sysemu_singlestep(request)) { | |
36df29d7 RM |
831 | if (unlikely(!arch_has_single_step())) |
832 | return -EIO; | |
833 | user_enable_single_step(child); | |
3a709703 | 834 | } else { |
36df29d7 | 835 | user_disable_single_step(child); |
3a709703 | 836 | } |
36df29d7 | 837 | |
b72c1869 ON |
838 | /* |
839 | * Change ->exit_code and ->state under siglock to avoid the race | |
840 | * with wait_task_stopped() in between; a non-zero ->exit_code will | |
841 | * wrongly look like another report from tracee. | |
842 | * | |
843 | * Note that we need siglock even if ->exit_code == data and/or this | |
844 | * status was not reported yet, the new status must not be cleared by | |
845 | * wait_task_stopped() after resume. | |
846 | * | |
847 | * If data == 0 we do not care if wait_task_stopped() reports the old | |
848 | * status and clears the code too; this can't race with the tracee, it | |
849 | * takes siglock after resume. | |
850 | */ | |
851 | need_siglock = data && !thread_group_empty(current); | |
852 | if (need_siglock) | |
853 | spin_lock_irq(&child->sighand->siglock); | |
36df29d7 | 854 | child->exit_code = data; |
0666fb51 | 855 | wake_up_state(child, __TASK_TRACED); |
b72c1869 ON |
856 | if (need_siglock) |
857 | spin_unlock_irq(&child->sighand->siglock); | |
36df29d7 RM |
858 | |
859 | return 0; | |
860 | } | |
861 | ||
2225a122 SS |
862 | #ifdef CONFIG_HAVE_ARCH_TRACEHOOK |
863 | ||
864 | static const struct user_regset * | |
865 | find_regset(const struct user_regset_view *view, unsigned int type) | |
866 | { | |
867 | const struct user_regset *regset; | |
868 | int n; | |
869 | ||
870 | for (n = 0; n < view->n; ++n) { | |
871 | regset = view->regsets + n; | |
872 | if (regset->core_note_type == type) | |
873 | return regset; | |
874 | } | |
875 | ||
876 | return NULL; | |
877 | } | |
878 | ||
879 | static int ptrace_regset(struct task_struct *task, int req, unsigned int type, | |
880 | struct iovec *kiov) | |
881 | { | |
882 | const struct user_regset_view *view = task_user_regset_view(task); | |
883 | const struct user_regset *regset = find_regset(view, type); | |
884 | int regset_no; | |
885 | ||
886 | if (!regset || (kiov->iov_len % regset->size) != 0) | |
c6a0dd7e | 887 | return -EINVAL; |
2225a122 SS |
888 | |
889 | regset_no = regset - view->regsets; | |
890 | kiov->iov_len = min(kiov->iov_len, | |
891 | (__kernel_size_t) (regset->n * regset->size)); | |
892 | ||
893 | if (req == PTRACE_GETREGSET) | |
894 | return copy_regset_to_user(task, view, regset_no, 0, | |
895 | kiov->iov_len, kiov->iov_base); | |
896 | else | |
897 | return copy_regset_from_user(task, view, regset_no, 0, | |
898 | kiov->iov_len, kiov->iov_base); | |
899 | } | |
900 | ||
e8440c14 JS |
901 | /* |
902 | * This is declared in linux/regset.h and defined in machine-dependent | |
903 | * code. We put the export here, near the primary machine-neutral use, | |
904 | * to ensure no machine forgets it. | |
905 | */ | |
906 | EXPORT_SYMBOL_GPL(task_user_regset_view); | |
201766a2 EK |
907 | |
908 | static unsigned long | |
909 | ptrace_get_syscall_info_entry(struct task_struct *child, struct pt_regs *regs, | |
910 | struct ptrace_syscall_info *info) | |
911 | { | |
912 | unsigned long args[ARRAY_SIZE(info->entry.args)]; | |
913 | int i; | |
914 | ||
915 | info->op = PTRACE_SYSCALL_INFO_ENTRY; | |
916 | info->entry.nr = syscall_get_nr(child, regs); | |
917 | syscall_get_arguments(child, regs, args); | |
918 | for (i = 0; i < ARRAY_SIZE(args); i++) | |
919 | info->entry.args[i] = args[i]; | |
920 | ||
921 | /* args is the last field in struct ptrace_syscall_info.entry */ | |
922 | return offsetofend(struct ptrace_syscall_info, entry.args); | |
923 | } | |
924 | ||
925 | static unsigned long | |
926 | ptrace_get_syscall_info_seccomp(struct task_struct *child, struct pt_regs *regs, | |
927 | struct ptrace_syscall_info *info) | |
928 | { | |
929 | /* | |
930 | * As struct ptrace_syscall_info.entry is currently a subset | |
931 | * of struct ptrace_syscall_info.seccomp, it makes sense to | |
932 | * initialize that subset using ptrace_get_syscall_info_entry(). | |
933 | * This can be reconsidered in the future if these structures | |
934 | * diverge significantly enough. | |
935 | */ | |
936 | ptrace_get_syscall_info_entry(child, regs, info); | |
937 | info->op = PTRACE_SYSCALL_INFO_SECCOMP; | |
938 | info->seccomp.ret_data = child->ptrace_message; | |
939 | ||
940 | /* ret_data is the last field in struct ptrace_syscall_info.seccomp */ | |
941 | return offsetofend(struct ptrace_syscall_info, seccomp.ret_data); | |
942 | } | |
943 | ||
944 | static unsigned long | |
945 | ptrace_get_syscall_info_exit(struct task_struct *child, struct pt_regs *regs, | |
946 | struct ptrace_syscall_info *info) | |
947 | { | |
948 | info->op = PTRACE_SYSCALL_INFO_EXIT; | |
949 | info->exit.rval = syscall_get_error(child, regs); | |
950 | info->exit.is_error = !!info->exit.rval; | |
951 | if (!info->exit.is_error) | |
952 | info->exit.rval = syscall_get_return_value(child, regs); | |
953 | ||
954 | /* is_error is the last field in struct ptrace_syscall_info.exit */ | |
955 | return offsetofend(struct ptrace_syscall_info, exit.is_error); | |
956 | } | |
957 | ||
958 | static int | |
959 | ptrace_get_syscall_info(struct task_struct *child, unsigned long user_size, | |
960 | void __user *datavp) | |
961 | { | |
962 | struct pt_regs *regs = task_pt_regs(child); | |
963 | struct ptrace_syscall_info info = { | |
964 | .op = PTRACE_SYSCALL_INFO_NONE, | |
965 | .arch = syscall_get_arch(child), | |
966 | .instruction_pointer = instruction_pointer(regs), | |
967 | .stack_pointer = user_stack_pointer(regs), | |
968 | }; | |
969 | unsigned long actual_size = offsetof(struct ptrace_syscall_info, entry); | |
970 | unsigned long write_size; | |
971 | ||
972 | /* | |
973 | * This does not need lock_task_sighand() to access | |
974 | * child->last_siginfo because ptrace_freeze_traced() | |
975 | * called earlier by ptrace_check_attach() ensures that | |
976 | * the tracee cannot go away and clear its last_siginfo. | |
977 | */ | |
978 | switch (child->last_siginfo ? child->last_siginfo->si_code : 0) { | |
979 | case SIGTRAP | 0x80: | |
980 | switch (child->ptrace_message) { | |
981 | case PTRACE_EVENTMSG_SYSCALL_ENTRY: | |
982 | actual_size = ptrace_get_syscall_info_entry(child, regs, | |
983 | &info); | |
984 | break; | |
985 | case PTRACE_EVENTMSG_SYSCALL_EXIT: | |
986 | actual_size = ptrace_get_syscall_info_exit(child, regs, | |
987 | &info); | |
988 | break; | |
989 | } | |
990 | break; | |
991 | case SIGTRAP | (PTRACE_EVENT_SECCOMP << 8): | |
992 | actual_size = ptrace_get_syscall_info_seccomp(child, regs, | |
993 | &info); | |
994 | break; | |
995 | } | |
996 | ||
997 | write_size = min(actual_size, user_size); | |
998 | return copy_to_user(datavp, &info, write_size) ? -EFAULT : actual_size; | |
999 | } | |
1000 | #endif /* CONFIG_HAVE_ARCH_TRACEHOOK */ | |
2225a122 | 1001 | |
1da177e4 | 1002 | int ptrace_request(struct task_struct *child, long request, |
4abf9869 | 1003 | unsigned long addr, unsigned long data) |
1da177e4 | 1004 | { |
fca26f26 | 1005 | bool seized = child->ptrace & PT_SEIZED; |
1da177e4 | 1006 | int ret = -EIO; |
ae7795bc | 1007 | kernel_siginfo_t siginfo, *si; |
9fed81dc NK |
1008 | void __user *datavp = (void __user *) data; |
1009 | unsigned long __user *datalp = datavp; | |
fca26f26 | 1010 | unsigned long flags; |
1da177e4 LT |
1011 | |
1012 | switch (request) { | |
16c3e389 RM |
1013 | case PTRACE_PEEKTEXT: |
1014 | case PTRACE_PEEKDATA: | |
1015 | return generic_ptrace_peekdata(child, addr, data); | |
1016 | case PTRACE_POKETEXT: | |
1017 | case PTRACE_POKEDATA: | |
1018 | return generic_ptrace_pokedata(child, addr, data); | |
1019 | ||
1da177e4 LT |
1020 | #ifdef PTRACE_OLDSETOPTIONS |
1021 | case PTRACE_OLDSETOPTIONS: | |
1022 | #endif | |
1023 | case PTRACE_SETOPTIONS: | |
1024 | ret = ptrace_setoptions(child, data); | |
1025 | break; | |
1026 | case PTRACE_GETEVENTMSG: | |
9fed81dc | 1027 | ret = put_user(child->ptrace_message, datalp); |
1da177e4 | 1028 | break; |
e16b2781 | 1029 | |
84c751bd AV |
1030 | case PTRACE_PEEKSIGINFO: |
1031 | ret = ptrace_peek_siginfo(child, addr, data); | |
1032 | break; | |
1033 | ||
1da177e4 | 1034 | case PTRACE_GETSIGINFO: |
e16b2781 RM |
1035 | ret = ptrace_getsiginfo(child, &siginfo); |
1036 | if (!ret) | |
9fed81dc | 1037 | ret = copy_siginfo_to_user(datavp, &siginfo); |
1da177e4 | 1038 | break; |
e16b2781 | 1039 | |
1da177e4 | 1040 | case PTRACE_SETSIGINFO: |
4cd2e0e7 EB |
1041 | ret = copy_siginfo_from_user(&siginfo, datavp); |
1042 | if (!ret) | |
e16b2781 | 1043 | ret = ptrace_setsiginfo(child, &siginfo); |
1da177e4 | 1044 | break; |
e16b2781 | 1045 | |
fcfc2aa0 AV |
1046 | case PTRACE_GETSIGMASK: { |
1047 | sigset_t *mask; | |
1048 | ||
29000cae AV |
1049 | if (addr != sizeof(sigset_t)) { |
1050 | ret = -EINVAL; | |
1051 | break; | |
1052 | } | |
1053 | ||
fcfc2aa0 AV |
1054 | if (test_tsk_restore_sigmask(child)) |
1055 | mask = &child->saved_sigmask; | |
1056 | else | |
1057 | mask = &child->blocked; | |
1058 | ||
1059 | if (copy_to_user(datavp, mask, sizeof(sigset_t))) | |
29000cae AV |
1060 | ret = -EFAULT; |
1061 | else | |
1062 | ret = 0; | |
1063 | ||
1064 | break; | |
fcfc2aa0 | 1065 | } |
29000cae AV |
1066 | |
1067 | case PTRACE_SETSIGMASK: { | |
1068 | sigset_t new_set; | |
1069 | ||
1070 | if (addr != sizeof(sigset_t)) { | |
1071 | ret = -EINVAL; | |
1072 | break; | |
1073 | } | |
1074 | ||
1075 | if (copy_from_user(&new_set, datavp, sizeof(sigset_t))) { | |
1076 | ret = -EFAULT; | |
1077 | break; | |
1078 | } | |
1079 | ||
1080 | sigdelsetmask(&new_set, sigmask(SIGKILL)|sigmask(SIGSTOP)); | |
1081 | ||
1082 | /* | |
1083 | * Every thread does recalc_sigpending() after resume, so | |
1084 | * retarget_shared_pending() and recalc_sigpending() are not | |
1085 | * called here. | |
1086 | */ | |
1087 | spin_lock_irq(&child->sighand->siglock); | |
1088 | child->blocked = new_set; | |
1089 | spin_unlock_irq(&child->sighand->siglock); | |
1090 | ||
fcfc2aa0 AV |
1091 | clear_tsk_restore_sigmask(child); |
1092 | ||
29000cae AV |
1093 | ret = 0; |
1094 | break; | |
1095 | } | |
1096 | ||
fca26f26 TH |
1097 | case PTRACE_INTERRUPT: |
1098 | /* | |
1099 | * Stop tracee without any side-effect on signal or job | |
1100 | * control. At least one trap is guaranteed to happen | |
1101 | * after this request. If @child is already trapped, the | |
1102 | * current trap is not disturbed and another trap will | |
1103 | * happen after the current trap is ended with PTRACE_CONT. | |
1104 | * | |
1105 | * The actual trap might not be PTRACE_EVENT_STOP trap but | |
1106 | * the pending condition is cleared regardless. | |
1107 | */ | |
1108 | if (unlikely(!seized || !lock_task_sighand(child, &flags))) | |
1109 | break; | |
1110 | ||
544b2c91 TH |
1111 | /* |
1112 | * INTERRUPT doesn't disturb existing trap sans one | |
1113 | * exception. If ptracer issued LISTEN for the current | |
1114 | * STOP, this INTERRUPT should clear LISTEN and re-trap | |
1115 | * tracee into STOP. | |
1116 | */ | |
fca26f26 | 1117 | if (likely(task_set_jobctl_pending(child, JOBCTL_TRAP_STOP))) |
910ffdb1 | 1118 | ptrace_signal_wake_up(child, child->jobctl & JOBCTL_LISTENING); |
544b2c91 TH |
1119 | |
1120 | unlock_task_sighand(child, &flags); | |
1121 | ret = 0; | |
1122 | break; | |
1123 | ||
1124 | case PTRACE_LISTEN: | |
1125 | /* | |
1126 | * Listen for events. Tracee must be in STOP. It's not | |
1127 | * resumed per-se but is not considered to be in TRACED by | |
1128 | * wait(2) or ptrace(2). If an async event (e.g. group | |
1129 | * stop state change) happens, tracee will enter STOP trap | |
1130 | * again. Alternatively, ptracer can issue INTERRUPT to | |
1131 | * finish listening and re-trap tracee into STOP. | |
1132 | */ | |
1133 | if (unlikely(!seized || !lock_task_sighand(child, &flags))) | |
1134 | break; | |
1135 | ||
1136 | si = child->last_siginfo; | |
f9d81f61 ON |
1137 | if (likely(si && (si->si_code >> 8) == PTRACE_EVENT_STOP)) { |
1138 | child->jobctl |= JOBCTL_LISTENING; | |
1139 | /* | |
1140 | * If NOTIFY is set, it means event happened between | |
1141 | * start of this trap and now. Trigger re-trap. | |
1142 | */ | |
1143 | if (child->jobctl & JOBCTL_TRAP_NOTIFY) | |
910ffdb1 | 1144 | ptrace_signal_wake_up(child, true); |
f9d81f61 ON |
1145 | ret = 0; |
1146 | } | |
fca26f26 | 1147 | unlock_task_sighand(child, &flags); |
fca26f26 TH |
1148 | break; |
1149 | ||
1bcf5482 AD |
1150 | case PTRACE_DETACH: /* detach a process that was attached. */ |
1151 | ret = ptrace_detach(child, data); | |
1152 | break; | |
36df29d7 | 1153 | |
9c1a1259 MF |
1154 | #ifdef CONFIG_BINFMT_ELF_FDPIC |
1155 | case PTRACE_GETFDPIC: { | |
e0129ef9 | 1156 | struct mm_struct *mm = get_task_mm(child); |
9c1a1259 MF |
1157 | unsigned long tmp = 0; |
1158 | ||
e0129ef9 ON |
1159 | ret = -ESRCH; |
1160 | if (!mm) | |
1161 | break; | |
1162 | ||
9c1a1259 MF |
1163 | switch (addr) { |
1164 | case PTRACE_GETFDPIC_EXEC: | |
e0129ef9 | 1165 | tmp = mm->context.exec_fdpic_loadmap; |
9c1a1259 MF |
1166 | break; |
1167 | case PTRACE_GETFDPIC_INTERP: | |
e0129ef9 | 1168 | tmp = mm->context.interp_fdpic_loadmap; |
9c1a1259 MF |
1169 | break; |
1170 | default: | |
1171 | break; | |
1172 | } | |
e0129ef9 | 1173 | mmput(mm); |
9c1a1259 | 1174 | |
9fed81dc | 1175 | ret = put_user(tmp, datalp); |
9c1a1259 MF |
1176 | break; |
1177 | } | |
1178 | #endif | |
1179 | ||
36df29d7 RM |
1180 | #ifdef PTRACE_SINGLESTEP |
1181 | case PTRACE_SINGLESTEP: | |
1182 | #endif | |
5b88abbf RM |
1183 | #ifdef PTRACE_SINGLEBLOCK |
1184 | case PTRACE_SINGLEBLOCK: | |
1185 | #endif | |
36df29d7 RM |
1186 | #ifdef PTRACE_SYSEMU |
1187 | case PTRACE_SYSEMU: | |
1188 | case PTRACE_SYSEMU_SINGLESTEP: | |
1189 | #endif | |
1190 | case PTRACE_SYSCALL: | |
1191 | case PTRACE_CONT: | |
1192 | return ptrace_resume(child, request, data); | |
1193 | ||
1194 | case PTRACE_KILL: | |
1195 | if (child->exit_state) /* already dead */ | |
1196 | return 0; | |
1197 | return ptrace_resume(child, request, SIGKILL); | |
1198 | ||
2225a122 SS |
1199 | #ifdef CONFIG_HAVE_ARCH_TRACEHOOK |
1200 | case PTRACE_GETREGSET: | |
29000cae | 1201 | case PTRACE_SETREGSET: { |
2225a122 | 1202 | struct iovec kiov; |
9fed81dc | 1203 | struct iovec __user *uiov = datavp; |
2225a122 | 1204 | |
96d4f267 | 1205 | if (!access_ok(uiov, sizeof(*uiov))) |
2225a122 SS |
1206 | return -EFAULT; |
1207 | ||
1208 | if (__get_user(kiov.iov_base, &uiov->iov_base) || | |
1209 | __get_user(kiov.iov_len, &uiov->iov_len)) | |
1210 | return -EFAULT; | |
1211 | ||
1212 | ret = ptrace_regset(child, request, addr, &kiov); | |
1213 | if (!ret) | |
1214 | ret = __put_user(kiov.iov_len, &uiov->iov_len); | |
1215 | break; | |
1216 | } | |
201766a2 EK |
1217 | |
1218 | case PTRACE_GET_SYSCALL_INFO: | |
1219 | ret = ptrace_get_syscall_info(child, addr, datavp); | |
1220 | break; | |
2225a122 | 1221 | #endif |
f8e529ed TA |
1222 | |
1223 | case PTRACE_SECCOMP_GET_FILTER: | |
1224 | ret = seccomp_get_filter(child, addr, datavp); | |
1225 | break; | |
1226 | ||
26500475 TA |
1227 | case PTRACE_SECCOMP_GET_METADATA: |
1228 | ret = seccomp_get_metadata(child, addr, datavp); | |
1229 | break; | |
1230 | ||
1da177e4 LT |
1231 | default: |
1232 | break; | |
1233 | } | |
1234 | ||
1235 | return ret; | |
1236 | } | |
481bed45 | 1237 | |
0ac15559 CH |
1238 | #ifndef arch_ptrace_attach |
1239 | #define arch_ptrace_attach(child) do { } while (0) | |
1240 | #endif | |
1241 | ||
4abf9869 NK |
1242 | SYSCALL_DEFINE4(ptrace, long, request, long, pid, unsigned long, addr, |
1243 | unsigned long, data) | |
481bed45 CH |
1244 | { |
1245 | struct task_struct *child; | |
1246 | long ret; | |
1247 | ||
6b9c7ed8 CH |
1248 | if (request == PTRACE_TRACEME) { |
1249 | ret = ptrace_traceme(); | |
6ea6dd93 HS |
1250 | if (!ret) |
1251 | arch_ptrace_attach(current); | |
481bed45 | 1252 | goto out; |
6b9c7ed8 CH |
1253 | } |
1254 | ||
2ee08260 MR |
1255 | child = find_get_task_by_vpid(pid); |
1256 | if (!child) { | |
1257 | ret = -ESRCH; | |
6b9c7ed8 CH |
1258 | goto out; |
1259 | } | |
481bed45 | 1260 | |
3544d72a | 1261 | if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) { |
aa9147c9 | 1262 | ret = ptrace_attach(child, request, addr, data); |
0ac15559 CH |
1263 | /* |
1264 | * Some architectures need to do book-keeping after | |
1265 | * a ptrace attach. | |
1266 | */ | |
1267 | if (!ret) | |
1268 | arch_ptrace_attach(child); | |
005f18df | 1269 | goto out_put_task_struct; |
481bed45 CH |
1270 | } |
1271 | ||
fca26f26 TH |
1272 | ret = ptrace_check_attach(child, request == PTRACE_KILL || |
1273 | request == PTRACE_INTERRUPT); | |
481bed45 CH |
1274 | if (ret < 0) |
1275 | goto out_put_task_struct; | |
1276 | ||
1277 | ret = arch_ptrace(child, request, addr, data); | |
9899d11f ON |
1278 | if (ret || request != PTRACE_DETACH) |
1279 | ptrace_unfreeze_traced(child); | |
481bed45 CH |
1280 | |
1281 | out_put_task_struct: | |
1282 | put_task_struct(child); | |
1283 | out: | |
481bed45 CH |
1284 | return ret; |
1285 | } | |
76647323 | 1286 | |
4abf9869 NK |
1287 | int generic_ptrace_peekdata(struct task_struct *tsk, unsigned long addr, |
1288 | unsigned long data) | |
76647323 AD |
1289 | { |
1290 | unsigned long tmp; | |
1291 | int copied; | |
1292 | ||
84d77d3f | 1293 | copied = ptrace_access_vm(tsk, addr, &tmp, sizeof(tmp), FOLL_FORCE); |
76647323 AD |
1294 | if (copied != sizeof(tmp)) |
1295 | return -EIO; | |
1296 | return put_user(tmp, (unsigned long __user *)data); | |
1297 | } | |
f284ce72 | 1298 | |
4abf9869 NK |
1299 | int generic_ptrace_pokedata(struct task_struct *tsk, unsigned long addr, |
1300 | unsigned long data) | |
f284ce72 AD |
1301 | { |
1302 | int copied; | |
1303 | ||
84d77d3f | 1304 | copied = ptrace_access_vm(tsk, addr, &data, sizeof(data), |
f307ab6d | 1305 | FOLL_FORCE | FOLL_WRITE); |
f284ce72 AD |
1306 | return (copied == sizeof(data)) ? 0 : -EIO; |
1307 | } | |
032d82d9 | 1308 | |
96b8936a | 1309 | #if defined CONFIG_COMPAT |
032d82d9 RM |
1310 | |
1311 | int compat_ptrace_request(struct task_struct *child, compat_long_t request, | |
1312 | compat_ulong_t addr, compat_ulong_t data) | |
1313 | { | |
1314 | compat_ulong_t __user *datap = compat_ptr(data); | |
1315 | compat_ulong_t word; | |
ae7795bc | 1316 | kernel_siginfo_t siginfo; |
032d82d9 RM |
1317 | int ret; |
1318 | ||
1319 | switch (request) { | |
1320 | case PTRACE_PEEKTEXT: | |
1321 | case PTRACE_PEEKDATA: | |
84d77d3f | 1322 | ret = ptrace_access_vm(child, addr, &word, sizeof(word), |
f307ab6d | 1323 | FOLL_FORCE); |
032d82d9 RM |
1324 | if (ret != sizeof(word)) |
1325 | ret = -EIO; | |
1326 | else | |
1327 | ret = put_user(word, datap); | |
1328 | break; | |
1329 | ||
1330 | case PTRACE_POKETEXT: | |
1331 | case PTRACE_POKEDATA: | |
84d77d3f | 1332 | ret = ptrace_access_vm(child, addr, &data, sizeof(data), |
f307ab6d | 1333 | FOLL_FORCE | FOLL_WRITE); |
032d82d9 RM |
1334 | ret = (ret != sizeof(data) ? -EIO : 0); |
1335 | break; | |
1336 | ||
1337 | case PTRACE_GETEVENTMSG: | |
1338 | ret = put_user((compat_ulong_t) child->ptrace_message, datap); | |
1339 | break; | |
1340 | ||
e16b2781 RM |
1341 | case PTRACE_GETSIGINFO: |
1342 | ret = ptrace_getsiginfo(child, &siginfo); | |
1343 | if (!ret) | |
1344 | ret = copy_siginfo_to_user32( | |
1345 | (struct compat_siginfo __user *) datap, | |
1346 | &siginfo); | |
1347 | break; | |
1348 | ||
1349 | case PTRACE_SETSIGINFO: | |
4cd2e0e7 EB |
1350 | ret = copy_siginfo_from_user32( |
1351 | &siginfo, (struct compat_siginfo __user *) datap); | |
1352 | if (!ret) | |
e16b2781 RM |
1353 | ret = ptrace_setsiginfo(child, &siginfo); |
1354 | break; | |
2225a122 SS |
1355 | #ifdef CONFIG_HAVE_ARCH_TRACEHOOK |
1356 | case PTRACE_GETREGSET: | |
1357 | case PTRACE_SETREGSET: | |
1358 | { | |
1359 | struct iovec kiov; | |
1360 | struct compat_iovec __user *uiov = | |
1361 | (struct compat_iovec __user *) datap; | |
1362 | compat_uptr_t ptr; | |
1363 | compat_size_t len; | |
1364 | ||
96d4f267 | 1365 | if (!access_ok(uiov, sizeof(*uiov))) |
2225a122 SS |
1366 | return -EFAULT; |
1367 | ||
1368 | if (__get_user(ptr, &uiov->iov_base) || | |
1369 | __get_user(len, &uiov->iov_len)) | |
1370 | return -EFAULT; | |
1371 | ||
1372 | kiov.iov_base = compat_ptr(ptr); | |
1373 | kiov.iov_len = len; | |
1374 | ||
1375 | ret = ptrace_regset(child, request, addr, &kiov); | |
1376 | if (!ret) | |
1377 | ret = __put_user(kiov.iov_len, &uiov->iov_len); | |
1378 | break; | |
1379 | } | |
1380 | #endif | |
e16b2781 | 1381 | |
032d82d9 RM |
1382 | default: |
1383 | ret = ptrace_request(child, request, addr, data); | |
1384 | } | |
1385 | ||
1386 | return ret; | |
1387 | } | |
c269f196 | 1388 | |
62a6fa97 HC |
1389 | COMPAT_SYSCALL_DEFINE4(ptrace, compat_long_t, request, compat_long_t, pid, |
1390 | compat_long_t, addr, compat_long_t, data) | |
c269f196 RM |
1391 | { |
1392 | struct task_struct *child; | |
1393 | long ret; | |
1394 | ||
c269f196 RM |
1395 | if (request == PTRACE_TRACEME) { |
1396 | ret = ptrace_traceme(); | |
1397 | goto out; | |
1398 | } | |
1399 | ||
2ee08260 MR |
1400 | child = find_get_task_by_vpid(pid); |
1401 | if (!child) { | |
1402 | ret = -ESRCH; | |
c269f196 RM |
1403 | goto out; |
1404 | } | |
1405 | ||
3544d72a | 1406 | if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) { |
aa9147c9 | 1407 | ret = ptrace_attach(child, request, addr, data); |
c269f196 RM |
1408 | /* |
1409 | * Some architectures need to do book-keeping after | |
1410 | * a ptrace attach. | |
1411 | */ | |
1412 | if (!ret) | |
1413 | arch_ptrace_attach(child); | |
1414 | goto out_put_task_struct; | |
1415 | } | |
1416 | ||
fca26f26 TH |
1417 | ret = ptrace_check_attach(child, request == PTRACE_KILL || |
1418 | request == PTRACE_INTERRUPT); | |
9899d11f | 1419 | if (!ret) { |
c269f196 | 1420 | ret = compat_arch_ptrace(child, request, addr, data); |
9899d11f ON |
1421 | if (ret || request != PTRACE_DETACH) |
1422 | ptrace_unfreeze_traced(child); | |
1423 | } | |
c269f196 RM |
1424 | |
1425 | out_put_task_struct: | |
1426 | put_task_struct(child); | |
1427 | out: | |
c269f196 RM |
1428 | return ret; |
1429 | } | |
96b8936a | 1430 | #endif /* CONFIG_COMPAT */ |