Line data Source code
1 : // SPDX-License-Identifier: GPL-2.0-only
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 :
11 : #include <linux/capability.h>
12 : #include <linux/export.h>
13 : #include <linux/sched.h>
14 : #include <linux/sched/mm.h>
15 : #include <linux/sched/coredump.h>
16 : #include <linux/sched/task.h>
17 : #include <linux/errno.h>
18 : #include <linux/mm.h>
19 : #include <linux/highmem.h>
20 : #include <linux/pagemap.h>
21 : #include <linux/ptrace.h>
22 : #include <linux/security.h>
23 : #include <linux/signal.h>
24 : #include <linux/uio.h>
25 : #include <linux/audit.h>
26 : #include <linux/pid_namespace.h>
27 : #include <linux/syscalls.h>
28 : #include <linux/uaccess.h>
29 : #include <linux/regset.h>
30 : #include <linux/hw_breakpoint.h>
31 : #include <linux/cn_proc.h>
32 : #include <linux/compat.h>
33 : #include <linux/sched/signal.h>
34 : #include <linux/minmax.h>
35 : #include <linux/syscall_user_dispatch.h>
36 :
37 : #include <asm/syscall.h> /* for syscall_get_* */
38 :
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 0 : 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 0 : mm = get_task_mm(tsk);
51 0 : if (!mm)
52 : return 0;
53 :
54 0 : if (!tsk->ptrace ||
55 0 : (current != tsk->parent) ||
56 0 : ((get_dumpable(mm) != SUID_DUMP_USER) &&
57 0 : !ptracer_capable(tsk, mm->user_ns))) {
58 0 : mmput(mm);
59 0 : return 0;
60 : }
61 :
62 0 : ret = __access_remote_vm(mm, addr, buf, len, gup_flags);
63 0 : mmput(mm);
64 :
65 0 : return ret;
66 : }
67 :
68 :
69 0 : void __ptrace_link(struct task_struct *child, struct task_struct *new_parent,
70 : const struct cred *ptracer_cred)
71 : {
72 0 : BUG_ON(!list_empty(&child->ptrace_entry));
73 0 : list_add(&child->ptrace_entry, &new_parent->ptraced);
74 0 : child->parent = new_parent;
75 0 : child->ptracer_cred = get_cred(ptracer_cred);
76 0 : }
77 :
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 : */
84 : static void ptrace_link(struct task_struct *child, struct task_struct *new_parent)
85 : {
86 0 : __ptrace_link(child, new_parent, current_cred());
87 : }
88 :
89 : /**
90 : * __ptrace_unlink - unlink ptracee and restore its execution state
91 : * @child: ptracee to be unlinked
92 : *
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.
113 : *
114 : * CONTEXT:
115 : * write_lock_irq(tasklist_lock)
116 : */
117 0 : void __ptrace_unlink(struct task_struct *child)
118 : {
119 : const struct cred *old_cred;
120 0 : BUG_ON(!child->ptrace);
121 :
122 0 : clear_task_syscall_work(child, SYSCALL_TRACE);
123 : #if defined(CONFIG_GENERIC_ENTRY) || defined(TIF_SYSCALL_EMU)
124 : clear_task_syscall_work(child, SYSCALL_EMU);
125 : #endif
126 :
127 0 : child->parent = child->real_parent;
128 0 : list_del_init(&child->ptrace_entry);
129 0 : old_cred = child->ptracer_cred;
130 0 : child->ptracer_cred = NULL;
131 0 : put_cred(old_cred);
132 :
133 0 : spin_lock(&child->sighand->siglock);
134 0 : child->ptrace = 0;
135 : /*
136 : * Clear all pending traps and TRAPPING. TRAPPING should be
137 : * cleared regardless of JOBCTL_STOP_PENDING. Do it explicitly.
138 : */
139 0 : task_clear_jobctl_pending(child, JOBCTL_TRAP_MASK);
140 0 : task_clear_jobctl_trapping(child);
141 :
142 : /*
143 : * Reinstate JOBCTL_STOP_PENDING if group stop is in effect and
144 : * @child isn't dead.
145 : */
146 0 : if (!(child->flags & PF_EXITING) &&
147 0 : (child->signal->flags & SIGNAL_STOP_STOPPED ||
148 : child->signal->group_stop_count)) {
149 0 : child->jobctl |= JOBCTL_STOP_PENDING;
150 :
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 0 : if (!(child->jobctl & JOBCTL_STOP_SIGMASK))
159 0 : child->jobctl |= SIGSTOP;
160 : }
161 :
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 : */
168 0 : if (child->jobctl & JOBCTL_STOP_PENDING || task_is_traced(child))
169 : ptrace_signal_wake_up(child, true);
170 :
171 0 : spin_unlock(&child->sighand->siglock);
172 0 : }
173 :
174 : static bool looks_like_a_spurious_pid(struct task_struct *task)
175 : {
176 0 : if (task->exit_code != ((PTRACE_EVENT_EXEC << 8) | SIGTRAP))
177 : return false;
178 :
179 0 : 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 :
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 : */
195 0 : static bool ptrace_freeze_traced(struct task_struct *task)
196 : {
197 0 : bool ret = false;
198 :
199 : /* Lockless, nobody but us can set this flag */
200 0 : if (task->jobctl & JOBCTL_LISTENING)
201 : return ret;
202 :
203 0 : spin_lock_irq(&task->sighand->siglock);
204 0 : if (task_is_traced(task) && !looks_like_a_spurious_pid(task) &&
205 0 : !__fatal_signal_pending(task)) {
206 0 : task->jobctl |= JOBCTL_PTRACE_FROZEN;
207 0 : ret = true;
208 : }
209 0 : spin_unlock_irq(&task->sighand->siglock);
210 :
211 0 : return ret;
212 : }
213 :
214 0 : static void ptrace_unfreeze_traced(struct task_struct *task)
215 : {
216 : unsigned long flags;
217 :
218 : /*
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.
222 : */
223 0 : if (lock_task_sighand(task, &flags)) {
224 0 : task->jobctl &= ~JOBCTL_PTRACE_FROZEN;
225 0 : if (__fatal_signal_pending(task)) {
226 0 : task->jobctl &= ~JOBCTL_TRACED;
227 0 : wake_up_state(task, __TASK_TRACED);
228 : }
229 0 : unlock_task_sighand(task, &flags);
230 : }
231 0 : }
232 :
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.
249 : */
250 0 : static int ptrace_check_attach(struct task_struct *child, bool ignore_state)
251 : {
252 0 : 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 0 : read_lock(&tasklist_lock);
262 0 : if (child->ptrace && child->parent == current) {
263 : /*
264 : * child->sighand can't be NULL, release_task()
265 : * does ptrace_unlink() before __exit_signal().
266 : */
267 0 : if (ignore_state || ptrace_freeze_traced(child))
268 : ret = 0;
269 : }
270 0 : read_unlock(&tasklist_lock);
271 :
272 0 : if (!ret && !ignore_state &&
273 0 : WARN_ON_ONCE(!wait_task_inactive(child, __TASK_TRACED|TASK_FROZEN)))
274 0 : ret = -ESRCH;
275 :
276 0 : return ret;
277 : }
278 :
279 0 : static bool ptrace_has_cap(struct user_namespace *ns, unsigned int mode)
280 : {
281 0 : if (mode & PTRACE_MODE_NOAUDIT)
282 0 : return ns_capable_noaudit(ns, CAP_SYS_PTRACE);
283 0 : return ns_capable(ns, CAP_SYS_PTRACE);
284 : }
285 :
286 : /* Returns 0 on success, -errno on denial. */
287 0 : static int __ptrace_may_access(struct task_struct *task, unsigned int mode)
288 : {
289 0 : const struct cred *cred = current_cred(), *tcred;
290 : struct mm_struct *mm;
291 : kuid_t caller_uid;
292 : kgid_t caller_gid;
293 :
294 0 : if (!(mode & PTRACE_MODE_FSCREDS) == !(mode & PTRACE_MODE_REALCREDS)) {
295 0 : WARN(1, "denying ptrace access check without PTRACE_MODE_*CREDS\n");
296 0 : return -EPERM;
297 : }
298 :
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 : */
307 :
308 : /* Don't let security modules deny introspection */
309 0 : if (same_thread_group(task, current))
310 : return 0;
311 : rcu_read_lock();
312 0 : if (mode & PTRACE_MODE_FSCREDS) {
313 0 : caller_uid = cred->fsuid;
314 0 : 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 0 : caller_uid = cred->uid;
325 0 : caller_gid = cred->gid;
326 : }
327 0 : tcred = __task_cred(task);
328 0 : if (uid_eq(caller_uid, tcred->euid) &&
329 0 : uid_eq(caller_uid, tcred->suid) &&
330 0 : uid_eq(caller_uid, tcred->uid) &&
331 0 : gid_eq(caller_gid, tcred->egid) &&
332 0 : gid_eq(caller_gid, tcred->sgid) &&
333 0 : gid_eq(caller_gid, tcred->gid))
334 : goto ok;
335 0 : if (ptrace_has_cap(tcred->user_ns, mode))
336 : goto ok;
337 : rcu_read_unlock();
338 0 : return -EPERM;
339 : ok:
340 : rcu_read_unlock();
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 0 : smp_rmb();
351 0 : mm = task->mm;
352 0 : if (mm &&
353 0 : ((get_dumpable(mm) != SUID_DUMP_USER) &&
354 0 : !ptrace_has_cap(mm->user_ns, mode)))
355 : return -EPERM;
356 :
357 0 : return security_ptrace_access_check(task, mode);
358 : }
359 :
360 0 : bool ptrace_may_access(struct task_struct *task, unsigned int mode)
361 : {
362 : int err;
363 0 : task_lock(task);
364 0 : err = __ptrace_may_access(task, mode);
365 0 : task_unlock(task);
366 0 : return !err;
367 : }
368 :
369 : static int check_ptrace_options(unsigned long data)
370 : {
371 0 : if (data & ~(unsigned long)PTRACE_O_MASK)
372 : return -EINVAL;
373 :
374 0 : 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 :
389 0 : static int ptrace_attach(struct task_struct *task, long request,
390 : unsigned long addr,
391 : unsigned long flags)
392 : {
393 0 : bool seize = (request == PTRACE_SEIZE);
394 : int retval;
395 :
396 0 : retval = -EIO;
397 0 : if (seize) {
398 0 : if (addr != 0)
399 : goto out;
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 : */
405 0 : if (flags & ~(unsigned long)PTRACE_O_MASK)
406 : goto out;
407 0 : retval = check_ptrace_options(flags);
408 0 : if (retval)
409 : return retval;
410 0 : flags = PT_PTRACED | PT_SEIZED | (flags << PT_OPT_FLAG_SHIFT);
411 : } else {
412 : flags = PT_PTRACED;
413 : }
414 :
415 0 : audit_ptrace(task);
416 :
417 0 : retval = -EPERM;
418 0 : if (unlikely(task->flags & PF_KTHREAD))
419 : goto out;
420 0 : if (same_thread_group(task, current))
421 : goto out;
422 :
423 : /*
424 : * Protect exec's credential calculations against our interference;
425 : * SUID, SGID and LSM creds get determined differently
426 : * under ptrace.
427 : */
428 0 : retval = -ERESTARTNOINTR;
429 0 : if (mutex_lock_interruptible(&task->signal->cred_guard_mutex))
430 : goto out;
431 :
432 0 : task_lock(task);
433 0 : retval = __ptrace_may_access(task, PTRACE_MODE_ATTACH_REALCREDS);
434 0 : task_unlock(task);
435 0 : if (retval)
436 : goto unlock_creds;
437 :
438 0 : write_lock_irq(&tasklist_lock);
439 0 : retval = -EPERM;
440 0 : if (unlikely(task->exit_state))
441 : goto unlock_tasklist;
442 0 : if (task->ptrace)
443 : goto unlock_tasklist;
444 :
445 0 : task->ptrace = flags;
446 :
447 0 : ptrace_link(task, current);
448 :
449 : /* SEIZE doesn't trap tracee on attach */
450 0 : if (!seize)
451 0 : send_sig_info(SIGSTOP, SEND_SIG_PRIV, task);
452 :
453 0 : spin_lock(&task->sighand->siglock);
454 :
455 : /*
456 : * If the task is already STOPPED, set JOBCTL_TRAP_STOP and
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 : */
472 0 : if (task_is_stopped(task) &&
473 0 : task_set_jobctl_pending(task, JOBCTL_TRAP_STOP | JOBCTL_TRAPPING)) {
474 0 : task->jobctl &= ~JOBCTL_STOPPED;
475 0 : signal_wake_up_state(task, __TASK_STOPPED);
476 : }
477 :
478 0 : spin_unlock(&task->sighand->siglock);
479 :
480 0 : retval = 0;
481 : unlock_tasklist:
482 0 : write_unlock_irq(&tasklist_lock);
483 : unlock_creds:
484 0 : mutex_unlock(&task->signal->cred_guard_mutex);
485 : out:
486 0 : if (!retval) {
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 0 : wait_on_bit(&task->jobctl, JOBCTL_TRAPPING_BIT, TASK_KILLABLE);
495 0 : proc_ptrace_connector(task, PTRACE_ATTACH);
496 : }
497 :
498 : return retval;
499 : }
500 :
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 : */
507 0 : static int ptrace_traceme(void)
508 : {
509 0 : int ret = -EPERM;
510 :
511 0 : write_lock_irq(&tasklist_lock);
512 : /* Are we already being traced? */
513 0 : if (!current->ptrace) {
514 0 : ret = security_ptrace_traceme(current->parent);
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 0 : if (!ret && !(current->real_parent->flags & PF_EXITING)) {
521 0 : current->ptrace = PT_PTRACED;
522 0 : ptrace_link(current, current->real_parent);
523 : }
524 : }
525 0 : write_unlock_irq(&tasklist_lock);
526 :
527 0 : return ret;
528 : }
529 :
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 0 : spin_lock(&sigh->siglock);
537 0 : ret = (sigh->action[SIGCHLD-1].sa.sa_handler == SIG_IGN) ||
538 0 : (sigh->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT);
539 0 : 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 : *
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().
557 : */
558 0 : static bool __ptrace_detach(struct task_struct *tracer, struct task_struct *p)
559 : {
560 : bool dead;
561 :
562 0 : __ptrace_unlink(p);
563 :
564 0 : if (p->exit_state != EXIT_ZOMBIE)
565 : return false;
566 :
567 0 : dead = !thread_group_leader(p);
568 :
569 0 : if (!dead && thread_group_empty(p)) {
570 0 : if (!same_thread_group(p->real_parent, tracer))
571 0 : dead = do_notify_parent(p, p->exit_signal);
572 0 : else if (ignoring_children(tracer->sighand)) {
573 0 : __wake_up_parent(p, tracer);
574 0 : dead = true;
575 : }
576 : }
577 : /* Mark it as in the process of being reaped. */
578 0 : if (dead)
579 0 : p->exit_state = EXIT_DEAD;
580 : return dead;
581 : }
582 :
583 0 : static int ptrace_detach(struct task_struct *child, unsigned int data)
584 : {
585 0 : if (!valid_signal(data))
586 : return -EIO;
587 :
588 : /* Architecture-specific hardware disable .. */
589 0 : ptrace_disable(child);
590 :
591 0 : write_lock_irq(&tasklist_lock);
592 : /*
593 : * We rely on ptrace_freeze_traced(). It can't be killed and
594 : * untraced by another thread, it can't be a zombie.
595 : */
596 0 : 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 0 : child->exit_code = data;
602 0 : __ptrace_detach(current, child);
603 0 : write_unlock_irq(&tasklist_lock);
604 :
605 0 : proc_ptrace_connector(child, PTRACE_DETACH);
606 :
607 0 : return 0;
608 : }
609 :
610 : /*
611 : * Detach all tasks we were using ptrace on. Called with tasklist held
612 : * for writing.
613 : */
614 0 : void exit_ptrace(struct task_struct *tracer, struct list_head *dead)
615 : {
616 : struct task_struct *p, *n;
617 :
618 0 : list_for_each_entry_safe(p, n, &tracer->ptraced, ptrace_entry) {
619 0 : if (unlikely(p->ptrace & PT_EXITKILL))
620 0 : send_sig_info(SIGKILL, SEND_SIG_PRIV, p);
621 :
622 0 : if (__ptrace_detach(tracer, p))
623 0 : list_add(&p->ptrace_entry, dead);
624 : }
625 0 : }
626 :
627 0 : int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len)
628 : {
629 0 : int copied = 0;
630 :
631 0 : while (len > 0) {
632 : char buf[128];
633 : int this_len, retval;
634 :
635 0 : this_len = (len > sizeof(buf)) ? sizeof(buf) : len;
636 0 : retval = ptrace_access_vm(tsk, src, buf, this_len, FOLL_FORCE);
637 :
638 0 : if (!retval) {
639 0 : if (copied)
640 : break;
641 0 : return -EIO;
642 : }
643 0 : if (copy_to_user(dst, buf, retval))
644 : return -EFAULT;
645 0 : copied += retval;
646 0 : src += retval;
647 0 : dst += retval;
648 0 : len -= retval;
649 : }
650 : return copied;
651 : }
652 :
653 0 : int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len)
654 : {
655 0 : int copied = 0;
656 :
657 0 : while (len > 0) {
658 : char buf[128];
659 : int this_len, retval;
660 :
661 0 : this_len = (len > sizeof(buf)) ? sizeof(buf) : len;
662 0 : if (copy_from_user(buf, src, this_len))
663 0 : return -EFAULT;
664 0 : retval = ptrace_access_vm(tsk, dst, buf, this_len,
665 : FOLL_FORCE | FOLL_WRITE);
666 0 : if (!retval) {
667 0 : if (copied)
668 : break;
669 : return -EIO;
670 : }
671 0 : copied += retval;
672 0 : src += retval;
673 0 : dst += retval;
674 0 : len -= retval;
675 : }
676 : return copied;
677 : }
678 :
679 : static int ptrace_setoptions(struct task_struct *child, unsigned long data)
680 : {
681 : unsigned flags;
682 : int ret;
683 :
684 0 : ret = check_ptrace_options(data);
685 0 : if (ret)
686 : return ret;
687 :
688 : /* Avoid intermediate state when all opts are cleared */
689 0 : flags = child->ptrace;
690 0 : flags &= ~(PTRACE_O_MASK << PT_OPT_FLAG_SHIFT);
691 0 : flags |= (data << PT_OPT_FLAG_SHIFT);
692 0 : child->ptrace = flags;
693 :
694 : return 0;
695 : }
696 :
697 0 : static int ptrace_getsiginfo(struct task_struct *child, kernel_siginfo_t *info)
698 : {
699 : unsigned long flags;
700 0 : int error = -ESRCH;
701 :
702 0 : if (lock_task_sighand(child, &flags)) {
703 0 : error = -EINVAL;
704 0 : if (likely(child->last_siginfo != NULL)) {
705 0 : copy_siginfo(info, child->last_siginfo);
706 0 : error = 0;
707 : }
708 0 : unlock_task_sighand(child, &flags);
709 : }
710 0 : return error;
711 : }
712 :
713 0 : static int ptrace_setsiginfo(struct task_struct *child, const kernel_siginfo_t *info)
714 : {
715 : unsigned long flags;
716 0 : int error = -ESRCH;
717 :
718 0 : if (lock_task_sighand(child, &flags)) {
719 0 : error = -EINVAL;
720 0 : if (likely(child->last_siginfo != NULL)) {
721 0 : copy_siginfo(child->last_siginfo, info);
722 0 : error = 0;
723 : }
724 0 : unlock_task_sighand(child, &flags);
725 : }
726 0 : return error;
727 : }
728 :
729 0 : 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 0 : ret = copy_from_user(&arg, (void __user *) addr,
739 : sizeof(struct ptrace_peeksiginfo_args));
740 0 : if (ret)
741 : return -EFAULT;
742 :
743 0 : if (arg.flags & ~PTRACE_PEEKSIGINFO_SHARED)
744 : return -EINVAL; /* unknown flags */
745 :
746 0 : if (arg.nr < 0)
747 : return -EINVAL;
748 :
749 : /* Ensure arg.off fits in an unsigned long */
750 : if (arg.off > ULONG_MAX)
751 : return 0;
752 :
753 0 : if (arg.flags & PTRACE_PEEKSIGINFO_SHARED)
754 0 : pending = &child->signal->shared_pending;
755 : else
756 0 : pending = &child->pending;
757 :
758 0 : for (i = 0; i < arg.nr; ) {
759 : kernel_siginfo_t info;
760 0 : unsigned long off = arg.off + i;
761 0 : bool found = false;
762 :
763 0 : spin_lock_irq(&child->sighand->siglock);
764 0 : list_for_each_entry(q, &pending->list, list) {
765 0 : if (!off--) {
766 0 : found = true;
767 0 : copy_siginfo(&info, &q->info);
768 0 : break;
769 : }
770 : }
771 0 : spin_unlock_irq(&child->sighand->siglock);
772 :
773 0 : if (!found) /* beyond the end of the list */
774 : break;
775 :
776 : #ifdef CONFIG_COMPAT
777 : if (unlikely(in_compat_syscall())) {
778 : compat_siginfo_t __user *uinfo = compat_ptr(data);
779 :
780 : if (copy_siginfo_to_user32(uinfo, &info)) {
781 : ret = -EFAULT;
782 : break;
783 : }
784 :
785 : } else
786 : #endif
787 : {
788 0 : siginfo_t __user *uinfo = (siginfo_t __user *) data;
789 :
790 0 : if (copy_siginfo_to_user(uinfo, &info)) {
791 : ret = -EFAULT;
792 : break;
793 : }
794 : }
795 :
796 0 : data += sizeof(siginfo_t);
797 0 : i++;
798 :
799 0 : if (signal_pending(current))
800 : break;
801 :
802 0 : cond_resched();
803 : }
804 :
805 0 : if (i > 0)
806 : return i;
807 :
808 0 : return ret;
809 : }
810 :
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,
817 : .rseq_abi_size = task->rseq_len,
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 :
829 : #define is_singlestep(request) ((request) == PTRACE_SINGLESTEP)
830 :
831 : #ifdef PTRACE_SINGLEBLOCK
832 : #define is_singleblock(request) ((request) == PTRACE_SINGLEBLOCK)
833 : #else
834 : #define is_singleblock(request) 0
835 : #endif
836 :
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 :
843 0 : static int ptrace_resume(struct task_struct *child, long request,
844 : unsigned long data)
845 : {
846 0 : if (!valid_signal(data))
847 : return -EIO;
848 :
849 0 : if (request == PTRACE_SYSCALL)
850 0 : set_task_syscall_work(child, SYSCALL_TRACE);
851 : else
852 0 : clear_task_syscall_work(child, SYSCALL_TRACE);
853 :
854 : #if defined(CONFIG_GENERIC_ENTRY) || defined(TIF_SYSCALL_EMU)
855 : if (request == PTRACE_SYSEMU || request == PTRACE_SYSEMU_SINGLESTEP)
856 : set_task_syscall_work(child, SYSCALL_EMU);
857 : else
858 : clear_task_syscall_work(child, SYSCALL_EMU);
859 : #endif
860 :
861 : if (is_singleblock(request)) {
862 : if (unlikely(!arch_has_block_step()))
863 : return -EIO;
864 : user_enable_block_step(child);
865 0 : } else if (is_singlestep(request) || is_sysemu_singlestep(request)) {
866 : if (unlikely(!arch_has_single_step()))
867 : return -EIO;
868 0 : user_enable_single_step(child);
869 : } else {
870 0 : user_disable_single_step(child);
871 : }
872 :
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.
881 : */
882 0 : spin_lock_irq(&child->sighand->siglock);
883 0 : child->exit_code = data;
884 0 : child->jobctl &= ~JOBCTL_TRACED;
885 0 : wake_up_state(child, __TASK_TRACED);
886 0 : spin_unlock_irq(&child->sighand->siglock);
887 :
888 0 : return 0;
889 : }
890 :
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)
916 : return -EINVAL;
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 :
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);
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 */
1030 :
1031 0 : int ptrace_request(struct task_struct *child, long request,
1032 : unsigned long addr, unsigned long data)
1033 : {
1034 0 : bool seized = child->ptrace & PT_SEIZED;
1035 0 : int ret = -EIO;
1036 : kernel_siginfo_t siginfo, *si;
1037 0 : void __user *datavp = (void __user *) data;
1038 0 : unsigned long __user *datalp = datavp;
1039 : unsigned long flags;
1040 :
1041 0 : switch (request) {
1042 : case PTRACE_PEEKTEXT:
1043 : case PTRACE_PEEKDATA:
1044 0 : return generic_ptrace_peekdata(child, addr, data);
1045 : case PTRACE_POKETEXT:
1046 : case PTRACE_POKEDATA:
1047 : return generic_ptrace_pokedata(child, addr, data);
1048 :
1049 : #ifdef PTRACE_OLDSETOPTIONS
1050 : case PTRACE_OLDSETOPTIONS:
1051 : #endif
1052 : case PTRACE_SETOPTIONS:
1053 0 : ret = ptrace_setoptions(child, data);
1054 : break;
1055 : case PTRACE_GETEVENTMSG:
1056 0 : ret = put_user(child->ptrace_message, datalp);
1057 : break;
1058 :
1059 : case PTRACE_PEEKSIGINFO:
1060 0 : ret = ptrace_peek_siginfo(child, addr, data);
1061 0 : break;
1062 :
1063 : case PTRACE_GETSIGINFO:
1064 0 : ret = ptrace_getsiginfo(child, &siginfo);
1065 0 : if (!ret)
1066 0 : ret = copy_siginfo_to_user(datavp, &siginfo);
1067 : break;
1068 :
1069 : case PTRACE_SETSIGINFO:
1070 0 : ret = copy_siginfo_from_user(&siginfo, datavp);
1071 0 : if (!ret)
1072 0 : ret = ptrace_setsiginfo(child, &siginfo);
1073 : break;
1074 :
1075 : case PTRACE_GETSIGMASK: {
1076 : sigset_t *mask;
1077 :
1078 0 : if (addr != sizeof(sigset_t)) {
1079 : ret = -EINVAL;
1080 : break;
1081 : }
1082 :
1083 0 : if (test_tsk_restore_sigmask(child))
1084 0 : mask = &child->saved_sigmask;
1085 : else
1086 0 : mask = &child->blocked;
1087 :
1088 0 : if (copy_to_user(datavp, mask, sizeof(sigset_t)))
1089 : ret = -EFAULT;
1090 : else
1091 0 : ret = 0;
1092 :
1093 : break;
1094 : }
1095 :
1096 : case PTRACE_SETSIGMASK: {
1097 : sigset_t new_set;
1098 :
1099 0 : if (addr != sizeof(sigset_t)) {
1100 : ret = -EINVAL;
1101 : break;
1102 : }
1103 :
1104 0 : if (copy_from_user(&new_set, datavp, sizeof(sigset_t))) {
1105 : ret = -EFAULT;
1106 : break;
1107 : }
1108 :
1109 0 : 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 0 : spin_lock_irq(&child->sighand->siglock);
1117 0 : child->blocked = new_set;
1118 0 : spin_unlock_irq(&child->sighand->siglock);
1119 :
1120 0 : clear_tsk_restore_sigmask(child);
1121 :
1122 0 : ret = 0;
1123 0 : break;
1124 : }
1125 :
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 0 : if (unlikely(!seized || !lock_task_sighand(child, &flags)))
1138 : break;
1139 :
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 : */
1146 0 : if (likely(task_set_jobctl_pending(child, JOBCTL_TRAP_STOP)))
1147 0 : ptrace_signal_wake_up(child, child->jobctl & JOBCTL_LISTENING);
1148 :
1149 0 : unlock_task_sighand(child, &flags);
1150 0 : ret = 0;
1151 0 : 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 0 : if (unlikely(!seized || !lock_task_sighand(child, &flags)))
1163 : break;
1164 :
1165 0 : si = child->last_siginfo;
1166 0 : if (likely(si && (si->si_code >> 8) == PTRACE_EVENT_STOP)) {
1167 0 : 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 0 : if (child->jobctl & JOBCTL_TRAP_NOTIFY)
1173 : ptrace_signal_wake_up(child, true);
1174 : ret = 0;
1175 : }
1176 0 : unlock_task_sighand(child, &flags);
1177 : break;
1178 :
1179 : case PTRACE_DETACH: /* detach a process that was attached. */
1180 0 : ret = ptrace_detach(child, data);
1181 0 : break;
1182 :
1183 : #ifdef CONFIG_BINFMT_ELF_FDPIC
1184 : case PTRACE_GETFDPIC: {
1185 : struct mm_struct *mm = get_task_mm(child);
1186 : unsigned long tmp = 0;
1187 :
1188 : ret = -ESRCH;
1189 : if (!mm)
1190 : break;
1191 :
1192 : switch (addr) {
1193 : case PTRACE_GETFDPIC_EXEC:
1194 : tmp = mm->context.exec_fdpic_loadmap;
1195 : break;
1196 : case PTRACE_GETFDPIC_INTERP:
1197 : tmp = mm->context.interp_fdpic_loadmap;
1198 : break;
1199 : default:
1200 : break;
1201 : }
1202 : mmput(mm);
1203 :
1204 : ret = put_user(tmp, datalp);
1205 : break;
1206 : }
1207 : #endif
1208 :
1209 : case PTRACE_SINGLESTEP:
1210 : #ifdef PTRACE_SINGLEBLOCK
1211 : case PTRACE_SINGLEBLOCK:
1212 : #endif
1213 : #ifdef PTRACE_SYSEMU
1214 : case PTRACE_SYSEMU:
1215 : case PTRACE_SYSEMU_SINGLESTEP:
1216 : #endif
1217 : case PTRACE_SYSCALL:
1218 : case PTRACE_CONT:
1219 0 : return ptrace_resume(child, request, data);
1220 :
1221 : case PTRACE_KILL:
1222 0 : send_sig_info(SIGKILL, SEND_SIG_NOINFO, child);
1223 0 : return 0;
1224 :
1225 : #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
1226 : case PTRACE_GETREGSET:
1227 : case PTRACE_SETREGSET: {
1228 : struct iovec kiov;
1229 : struct iovec __user *uiov = datavp;
1230 :
1231 : if (!access_ok(uiov, sizeof(*uiov)))
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 : }
1243 :
1244 : case PTRACE_GET_SYSCALL_INFO:
1245 : ret = ptrace_get_syscall_info(child, addr, datavp);
1246 : break;
1247 : #endif
1248 :
1249 : case PTRACE_SECCOMP_GET_FILTER:
1250 0 : ret = seccomp_get_filter(child, addr, datavp);
1251 0 : break;
1252 :
1253 : case PTRACE_SECCOMP_GET_METADATA:
1254 0 : ret = seccomp_get_metadata(child, addr, datavp);
1255 0 : break;
1256 :
1257 : #ifdef CONFIG_RSEQ
1258 : case PTRACE_GET_RSEQ_CONFIGURATION:
1259 : ret = ptrace_get_rseq_configuration(child, addr, datavp);
1260 : break;
1261 : #endif
1262 :
1263 : case PTRACE_SET_SYSCALL_USER_DISPATCH_CONFIG:
1264 0 : ret = syscall_user_dispatch_set_config(child, addr, datavp);
1265 0 : break;
1266 :
1267 : case PTRACE_GET_SYSCALL_USER_DISPATCH_CONFIG:
1268 0 : ret = syscall_user_dispatch_get_config(child, addr, datavp);
1269 0 : break;
1270 :
1271 : default:
1272 : break;
1273 : }
1274 :
1275 : return ret;
1276 : }
1277 :
1278 0 : SYSCALL_DEFINE4(ptrace, long, request, long, pid, unsigned long, addr,
1279 : unsigned long, data)
1280 : {
1281 : struct task_struct *child;
1282 : long ret;
1283 :
1284 0 : if (request == PTRACE_TRACEME) {
1285 0 : ret = ptrace_traceme();
1286 0 : goto out;
1287 : }
1288 :
1289 0 : child = find_get_task_by_vpid(pid);
1290 0 : if (!child) {
1291 : ret = -ESRCH;
1292 : goto out;
1293 : }
1294 :
1295 0 : if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) {
1296 0 : ret = ptrace_attach(child, request, addr, data);
1297 0 : goto out_put_task_struct;
1298 : }
1299 :
1300 0 : ret = ptrace_check_attach(child, request == PTRACE_KILL ||
1301 0 : request == PTRACE_INTERRUPT);
1302 0 : if (ret < 0)
1303 : goto out_put_task_struct;
1304 :
1305 0 : ret = arch_ptrace(child, request, addr, data);
1306 0 : if (ret || request != PTRACE_DETACH)
1307 0 : ptrace_unfreeze_traced(child);
1308 :
1309 : out_put_task_struct:
1310 0 : put_task_struct(child);
1311 : out:
1312 0 : return ret;
1313 : }
1314 :
1315 0 : int generic_ptrace_peekdata(struct task_struct *tsk, unsigned long addr,
1316 : unsigned long data)
1317 : {
1318 : unsigned long tmp;
1319 : int copied;
1320 :
1321 0 : copied = ptrace_access_vm(tsk, addr, &tmp, sizeof(tmp), FOLL_FORCE);
1322 0 : if (copied != sizeof(tmp))
1323 : return -EIO;
1324 0 : return put_user(tmp, (unsigned long __user *)data);
1325 : }
1326 :
1327 0 : int generic_ptrace_pokedata(struct task_struct *tsk, unsigned long addr,
1328 : unsigned long data)
1329 : {
1330 : int copied;
1331 :
1332 0 : copied = ptrace_access_vm(tsk, addr, &data, sizeof(data),
1333 : FOLL_FORCE | FOLL_WRITE);
1334 0 : return (copied == sizeof(data)) ? 0 : -EIO;
1335 : }
1336 :
1337 : #if defined CONFIG_COMPAT
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;
1344 : kernel_siginfo_t siginfo;
1345 : int ret;
1346 :
1347 : switch (request) {
1348 : case PTRACE_PEEKTEXT:
1349 : case PTRACE_PEEKDATA:
1350 : ret = ptrace_access_vm(child, addr, &word, sizeof(word),
1351 : FOLL_FORCE);
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:
1360 : ret = ptrace_access_vm(child, addr, &data, sizeof(data),
1361 : FOLL_FORCE | FOLL_WRITE);
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 :
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:
1378 : ret = copy_siginfo_from_user32(
1379 : &siginfo, (struct compat_siginfo __user *) datap);
1380 : if (!ret)
1381 : ret = ptrace_setsiginfo(child, &siginfo);
1382 : break;
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 :
1393 : if (!access_ok(uiov, sizeof(*uiov)))
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
1409 :
1410 : default:
1411 : ret = ptrace_request(child, request, addr, data);
1412 : }
1413 :
1414 : return ret;
1415 : }
1416 :
1417 : COMPAT_SYSCALL_DEFINE4(ptrace, compat_long_t, request, compat_long_t, pid,
1418 : compat_long_t, addr, compat_long_t, data)
1419 : {
1420 : struct task_struct *child;
1421 : long ret;
1422 :
1423 : if (request == PTRACE_TRACEME) {
1424 : ret = ptrace_traceme();
1425 : goto out;
1426 : }
1427 :
1428 : child = find_get_task_by_vpid(pid);
1429 : if (!child) {
1430 : ret = -ESRCH;
1431 : goto out;
1432 : }
1433 :
1434 : if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) {
1435 : ret = ptrace_attach(child, request, addr, data);
1436 : goto out_put_task_struct;
1437 : }
1438 :
1439 : ret = ptrace_check_attach(child, request == PTRACE_KILL ||
1440 : request == PTRACE_INTERRUPT);
1441 : if (!ret) {
1442 : ret = compat_arch_ptrace(child, request, addr, data);
1443 : if (ret || request != PTRACE_DETACH)
1444 : ptrace_unfreeze_traced(child);
1445 : }
1446 :
1447 : out_put_task_struct:
1448 : put_task_struct(child);
1449 : out:
1450 : return ret;
1451 : }
1452 : #endif /* CONFIG_COMPAT */
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