2 * linux/kernel/ptrace.c
4 * (C) Copyright 1999 Linus Torvalds
6 * Common interfaces for "ptrace()" which we do not want
7 * to continually duplicate across every architecture.
10 #include <linux/capability.h>
11 #include <linux/export.h>
12 #include <linux/sched.h>
13 #include <linux/errno.h>
15 #include <linux/highmem.h>
16 #include <linux/pagemap.h>
17 #include <linux/ptrace.h>
18 #include <linux/security.h>
19 #include <linux/signal.h>
20 #include <linux/uio.h>
21 #include <linux/audit.h>
22 #include <linux/pid_namespace.h>
23 #include <linux/syscalls.h>
24 #include <linux/uaccess.h>
25 #include <linux/regset.h>
26 #include <linux/hw_breakpoint.h>
27 #include <linux/cn_proc.h>
28 #include <linux/compat.h>
31 * Access another process' address space via ptrace.
32 * Source/target buffer must be kernel space,
33 * Do not walk the page table directly, use get_user_pages
35 int ptrace_access_vm(struct task_struct *tsk, unsigned long addr,
36 void *buf, int len, unsigned int gup_flags)
41 mm = get_task_mm(tsk);
46 (current != tsk->parent) ||
47 ((get_dumpable(mm) != SUID_DUMP_USER) &&
48 !ptracer_capable(tsk, mm->user_ns))) {
53 ret = __access_remote_vm(tsk, mm, addr, buf, len, gup_flags);
60 void __ptrace_link(struct task_struct *child, struct task_struct *new_parent,
61 const struct cred *ptracer_cred)
63 BUG_ON(!list_empty(&child->ptrace_entry));
64 list_add(&child->ptrace_entry, &new_parent->ptraced);
65 child->parent = new_parent;
66 child->ptracer_cred = get_cred(ptracer_cred);
70 * ptrace a task: make the debugger its new parent and
71 * move it to the ptrace list.
73 * Must be called with the tasklist lock write-held.
75 static void ptrace_link(struct task_struct *child, struct task_struct *new_parent)
77 __ptrace_link(child, new_parent, current_cred());
81 * __ptrace_unlink - unlink ptracee and restore its execution state
82 * @child: ptracee to be unlinked
84 * Remove @child from the ptrace list, move it back to the original parent,
85 * and restore the execution state so that it conforms to the group stop
88 * Unlinking can happen via two paths - explicit PTRACE_DETACH or ptracer
89 * exiting. For PTRACE_DETACH, unless the ptracee has been killed between
90 * ptrace_check_attach() and here, it's guaranteed to be in TASK_TRACED.
91 * If the ptracer is exiting, the ptracee can be in any state.
93 * After detach, the ptracee should be in a state which conforms to the
94 * group stop. If the group is stopped or in the process of stopping, the
95 * ptracee should be put into TASK_STOPPED; otherwise, it should be woken
96 * up from TASK_TRACED.
98 * If the ptracee is in TASK_TRACED and needs to be moved to TASK_STOPPED,
99 * it goes through TRACED -> RUNNING -> STOPPED transition which is similar
100 * to but in the opposite direction of what happens while attaching to a
101 * stopped task. However, in this direction, the intermediate RUNNING
102 * state is not hidden even from the current ptracer and if it immediately
103 * re-attaches and performs a WNOHANG wait(2), it may fail.
106 * write_lock_irq(tasklist_lock)
108 void __ptrace_unlink(struct task_struct *child)
110 const struct cred *old_cred;
111 BUG_ON(!child->ptrace);
113 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
115 child->parent = child->real_parent;
116 list_del_init(&child->ptrace_entry);
117 old_cred = child->ptracer_cred;
118 child->ptracer_cred = NULL;
121 spin_lock(&child->sighand->siglock);
124 * Clear all pending traps and TRAPPING. TRAPPING should be
125 * cleared regardless of JOBCTL_STOP_PENDING. Do it explicitly.
127 task_clear_jobctl_pending(child, JOBCTL_TRAP_MASK);
128 task_clear_jobctl_trapping(child);
131 * Reinstate JOBCTL_STOP_PENDING if group stop is in effect and
134 if (!(child->flags & PF_EXITING) &&
135 (child->signal->flags & SIGNAL_STOP_STOPPED ||
136 child->signal->group_stop_count)) {
137 child->jobctl |= JOBCTL_STOP_PENDING;
140 * This is only possible if this thread was cloned by the
141 * traced task running in the stopped group, set the signal
142 * for the future reports.
143 * FIXME: we should change ptrace_init_task() to handle this
146 if (!(child->jobctl & JOBCTL_STOP_SIGMASK))
147 child->jobctl |= SIGSTOP;
151 * If transition to TASK_STOPPED is pending or in TASK_TRACED, kick
152 * @child in the butt. Note that @resume should be used iff @child
153 * is in TASK_TRACED; otherwise, we might unduly disrupt
154 * TASK_KILLABLE sleeps.
156 if (child->jobctl & JOBCTL_STOP_PENDING || task_is_traced(child))
157 ptrace_signal_wake_up(child, true);
159 spin_unlock(&child->sighand->siglock);
162 static bool looks_like_a_spurious_pid(struct task_struct *task)
164 if (task->exit_code != ((PTRACE_EVENT_EXEC << 8) | SIGTRAP))
167 if (task_pid_vnr(task) == task->ptrace_message)
170 * The tracee changed its pid but the PTRACE_EVENT_EXEC event
171 * was not wait()'ed, most probably debugger targets the old
172 * leader which was destroyed in de_thread().
177 /* Ensure that nothing can wake it up, even SIGKILL */
178 static bool ptrace_freeze_traced(struct task_struct *task)
182 /* Lockless, nobody but us can set this flag */
183 if (task->jobctl & JOBCTL_LISTENING)
186 spin_lock_irq(&task->sighand->siglock);
187 if (task_is_traced(task) && !looks_like_a_spurious_pid(task) &&
188 !__fatal_signal_pending(task)) {
189 task->state = __TASK_TRACED;
192 spin_unlock_irq(&task->sighand->siglock);
197 static void ptrace_unfreeze_traced(struct task_struct *task)
199 if (task->state != __TASK_TRACED)
202 WARN_ON(!task->ptrace || task->parent != current);
205 * PTRACE_LISTEN can allow ptrace_trap_notify to wake us up remotely.
206 * Recheck state under the lock to close this race.
208 spin_lock_irq(&task->sighand->siglock);
209 if (task->state == __TASK_TRACED) {
210 if (__fatal_signal_pending(task))
211 wake_up_state(task, __TASK_TRACED);
213 task->state = TASK_TRACED;
215 spin_unlock_irq(&task->sighand->siglock);
219 * ptrace_check_attach - check whether ptracee is ready for ptrace operation
220 * @child: ptracee to check for
221 * @ignore_state: don't check whether @child is currently %TASK_TRACED
223 * Check whether @child is being ptraced by %current and ready for further
224 * ptrace operations. If @ignore_state is %false, @child also should be in
225 * %TASK_TRACED state and on return the child is guaranteed to be traced
226 * and not executing. If @ignore_state is %true, @child can be in any
230 * Grabs and releases tasklist_lock and @child->sighand->siglock.
233 * 0 on success, -ESRCH if %child is not ready.
235 static int ptrace_check_attach(struct task_struct *child, bool ignore_state)
240 * We take the read lock around doing both checks to close a
241 * possible race where someone else was tracing our child and
242 * detached between these two checks. After this locked check,
243 * we are sure that this is our traced child and that can only
244 * be changed by us so it's not changing right after this.
246 read_lock(&tasklist_lock);
247 if (child->ptrace && child->parent == current) {
248 WARN_ON(child->state == __TASK_TRACED);
250 * child->sighand can't be NULL, release_task()
251 * does ptrace_unlink() before __exit_signal().
253 if (ignore_state || ptrace_freeze_traced(child))
256 read_unlock(&tasklist_lock);
258 if (!ret && !ignore_state) {
259 if (!wait_task_inactive(child, __TASK_TRACED)) {
261 * This can only happen if may_ptrace_stop() fails and
262 * ptrace_stop() changes ->state back to TASK_RUNNING,
263 * so we should not worry about leaking __TASK_TRACED.
265 WARN_ON(child->state == __TASK_TRACED);
273 static int ptrace_has_cap(struct user_namespace *ns, unsigned int mode)
275 if (mode & PTRACE_MODE_SCHED)
278 if (mode & PTRACE_MODE_NOAUDIT)
279 return has_ns_capability_noaudit(current, ns, CAP_SYS_PTRACE);
281 return has_ns_capability(current, ns, CAP_SYS_PTRACE);
284 /* Returns 0 on success, -errno on denial. */
285 static int __ptrace_may_access(struct task_struct *task, unsigned int mode)
287 const struct cred *cred = current_cred(), *tcred;
288 struct mm_struct *mm;
292 if (!(mode & PTRACE_MODE_FSCREDS) == !(mode & PTRACE_MODE_REALCREDS)) {
293 WARN(1, "denying ptrace access check without PTRACE_MODE_*CREDS\n");
297 /* May we inspect the given task?
298 * This check is used both for attaching with ptrace
299 * and for allowing access to sensitive information in /proc.
301 * ptrace_attach denies several cases that /proc allows
302 * because setting up the necessary parent/child relationship
303 * or halting the specified task is impossible.
306 /* Don't let security modules deny introspection */
307 if (same_thread_group(task, current))
310 if (mode & PTRACE_MODE_FSCREDS) {
311 caller_uid = cred->fsuid;
312 caller_gid = cred->fsgid;
315 * Using the euid would make more sense here, but something
316 * in userland might rely on the old behavior, and this
317 * shouldn't be a security problem since
318 * PTRACE_MODE_REALCREDS implies that the caller explicitly
319 * used a syscall that requests access to another process
320 * (and not a filesystem syscall to procfs).
322 caller_uid = cred->uid;
323 caller_gid = cred->gid;
325 tcred = __task_cred(task);
326 if (uid_eq(caller_uid, tcred->euid) &&
327 uid_eq(caller_uid, tcred->suid) &&
328 uid_eq(caller_uid, tcred->uid) &&
329 gid_eq(caller_gid, tcred->egid) &&
330 gid_eq(caller_gid, tcred->sgid) &&
331 gid_eq(caller_gid, tcred->gid))
333 if (ptrace_has_cap(tcred->user_ns, mode))
340 * If a task drops privileges and becomes nondumpable (through a syscall
341 * like setresuid()) while we are trying to access it, we must ensure
342 * that the dumpability is read after the credentials; otherwise,
343 * we may be able to attach to a task that we shouldn't be able to
344 * attach to (as if the task had dropped privileges without becoming
346 * Pairs with a write barrier in commit_creds().
351 ((get_dumpable(mm) != SUID_DUMP_USER) &&
352 !ptrace_has_cap(mm->user_ns, mode)))
355 if (mode & PTRACE_MODE_SCHED)
357 return security_ptrace_access_check(task, mode);
360 bool ptrace_may_access_sched(struct task_struct *task, unsigned int mode)
362 return __ptrace_may_access(task, mode | PTRACE_MODE_SCHED);
365 bool ptrace_may_access(struct task_struct *task, unsigned int mode)
369 err = __ptrace_may_access(task, mode);
374 static int ptrace_attach(struct task_struct *task, long request,
378 bool seize = (request == PTRACE_SEIZE);
385 if (flags & ~(unsigned long)PTRACE_O_MASK)
387 flags = PT_PTRACED | PT_SEIZED | (flags << PT_OPT_FLAG_SHIFT);
395 if (unlikely(task->flags & PF_KTHREAD))
397 if (same_thread_group(task, current))
401 * Protect exec's credential calculations against our interference;
402 * SUID, SGID and LSM creds get determined differently
405 retval = -ERESTARTNOINTR;
406 if (mutex_lock_interruptible(&task->signal->cred_guard_mutex))
410 retval = __ptrace_may_access(task, PTRACE_MODE_ATTACH_REALCREDS);
415 write_lock_irq(&tasklist_lock);
417 if (unlikely(task->exit_state))
418 goto unlock_tasklist;
420 goto unlock_tasklist;
424 task->ptrace = flags;
426 ptrace_link(task, current);
428 /* SEIZE doesn't trap tracee on attach */
430 send_sig_info(SIGSTOP, SEND_SIG_FORCED, task);
432 spin_lock(&task->sighand->siglock);
435 * If the task is already STOPPED, set JOBCTL_TRAP_STOP and
436 * TRAPPING, and kick it so that it transits to TRACED. TRAPPING
437 * will be cleared if the child completes the transition or any
438 * event which clears the group stop states happens. We'll wait
439 * for the transition to complete before returning from this
442 * This hides STOPPED -> RUNNING -> TRACED transition from the
443 * attaching thread but a different thread in the same group can
444 * still observe the transient RUNNING state. IOW, if another
445 * thread's WNOHANG wait(2) on the stopped tracee races against
446 * ATTACH, the wait(2) may fail due to the transient RUNNING.
448 * The following task_is_stopped() test is safe as both transitions
449 * in and out of STOPPED are protected by siglock.
451 if (task_is_stopped(task) &&
452 task_set_jobctl_pending(task, JOBCTL_TRAP_STOP | JOBCTL_TRAPPING))
453 signal_wake_up_state(task, __TASK_STOPPED);
455 spin_unlock(&task->sighand->siglock);
459 write_unlock_irq(&tasklist_lock);
461 mutex_unlock(&task->signal->cred_guard_mutex);
465 * We do not bother to change retval or clear JOBCTL_TRAPPING
466 * if wait_on_bit() was interrupted by SIGKILL. The tracer will
467 * not return to user-mode, it will exit and clear this bit in
468 * __ptrace_unlink() if it wasn't already cleared by the tracee;
469 * and until then nobody can ptrace this task.
471 wait_on_bit(&task->jobctl, JOBCTL_TRAPPING_BIT, TASK_KILLABLE);
472 proc_ptrace_connector(task, PTRACE_ATTACH);
479 * ptrace_traceme -- helper for PTRACE_TRACEME
481 * Performs checks and sets PT_PTRACED.
482 * Should be used by all ptrace implementations for PTRACE_TRACEME.
484 static int ptrace_traceme(void)
488 write_lock_irq(&tasklist_lock);
489 /* Are we already being traced? */
490 if (!current->ptrace) {
491 ret = security_ptrace_traceme(current->parent);
493 * Check PF_EXITING to ensure ->real_parent has not passed
494 * exit_ptrace(). Otherwise we don't report the error but
495 * pretend ->real_parent untraces us right after return.
497 if (!ret && !(current->real_parent->flags & PF_EXITING)) {
498 current->ptrace = PT_PTRACED;
499 ptrace_link(current, current->real_parent);
502 write_unlock_irq(&tasklist_lock);
508 * Called with irqs disabled, returns true if childs should reap themselves.
510 static int ignoring_children(struct sighand_struct *sigh)
513 spin_lock(&sigh->siglock);
514 ret = (sigh->action[SIGCHLD-1].sa.sa_handler == SIG_IGN) ||
515 (sigh->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT);
516 spin_unlock(&sigh->siglock);
521 * Called with tasklist_lock held for writing.
522 * Unlink a traced task, and clean it up if it was a traced zombie.
523 * Return true if it needs to be reaped with release_task().
524 * (We can't call release_task() here because we already hold tasklist_lock.)
526 * If it's a zombie, our attachedness prevented normal parent notification
527 * or self-reaping. Do notification now if it would have happened earlier.
528 * If it should reap itself, return true.
530 * If it's our own child, there is no notification to do. But if our normal
531 * children self-reap, then this child was prevented by ptrace and we must
532 * reap it now, in that case we must also wake up sub-threads sleeping in
535 static bool __ptrace_detach(struct task_struct *tracer, struct task_struct *p)
541 if (p->exit_state != EXIT_ZOMBIE)
544 dead = !thread_group_leader(p);
546 if (!dead && thread_group_empty(p)) {
547 if (!same_thread_group(p->real_parent, tracer))
548 dead = do_notify_parent(p, p->exit_signal);
549 else if (ignoring_children(tracer->sighand)) {
550 __wake_up_parent(p, tracer);
554 /* Mark it as in the process of being reaped. */
556 p->exit_state = EXIT_DEAD;
560 static int ptrace_detach(struct task_struct *child, unsigned int data)
562 if (!valid_signal(data))
565 /* Architecture-specific hardware disable .. */
566 ptrace_disable(child);
568 write_lock_irq(&tasklist_lock);
570 * We rely on ptrace_freeze_traced(). It can't be killed and
571 * untraced by another thread, it can't be a zombie.
573 WARN_ON(!child->ptrace || child->exit_state);
575 * tasklist_lock avoids the race with wait_task_stopped(), see
576 * the comment in ptrace_resume().
578 child->exit_code = data;
579 __ptrace_detach(current, child);
580 write_unlock_irq(&tasklist_lock);
582 proc_ptrace_connector(child, PTRACE_DETACH);
588 * Detach all tasks we were using ptrace on. Called with tasklist held
591 void exit_ptrace(struct task_struct *tracer, struct list_head *dead)
593 struct task_struct *p, *n;
595 list_for_each_entry_safe(p, n, &tracer->ptraced, ptrace_entry) {
596 if (unlikely(p->ptrace & PT_EXITKILL))
597 send_sig_info(SIGKILL, SEND_SIG_FORCED, p);
599 if (__ptrace_detach(tracer, p))
600 list_add(&p->ptrace_entry, dead);
604 int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len)
610 int this_len, retval;
612 this_len = (len > sizeof(buf)) ? sizeof(buf) : len;
613 retval = ptrace_access_vm(tsk, src, buf, this_len, FOLL_FORCE);
620 if (copy_to_user(dst, buf, retval))
630 int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len)
636 int this_len, retval;
638 this_len = (len > sizeof(buf)) ? sizeof(buf) : len;
639 if (copy_from_user(buf, src, this_len))
641 retval = ptrace_access_vm(tsk, dst, buf, this_len,
642 FOLL_FORCE | FOLL_WRITE);
656 static int ptrace_setoptions(struct task_struct *child, unsigned long data)
660 if (data & ~(unsigned long)PTRACE_O_MASK)
663 if (unlikely(data & PTRACE_O_SUSPEND_SECCOMP)) {
664 if (!IS_ENABLED(CONFIG_CHECKPOINT_RESTORE) ||
665 !IS_ENABLED(CONFIG_SECCOMP))
668 if (!capable(CAP_SYS_ADMIN))
671 if (seccomp_mode(¤t->seccomp) != SECCOMP_MODE_DISABLED ||
672 current->ptrace & PT_SUSPEND_SECCOMP)
676 /* Avoid intermediate state when all opts are cleared */
677 flags = child->ptrace;
678 flags &= ~(PTRACE_O_MASK << PT_OPT_FLAG_SHIFT);
679 flags |= (data << PT_OPT_FLAG_SHIFT);
680 child->ptrace = flags;
685 static int ptrace_getsiginfo(struct task_struct *child, siginfo_t *info)
690 if (lock_task_sighand(child, &flags)) {
692 if (likely(child->last_siginfo != NULL)) {
693 *info = *child->last_siginfo;
696 unlock_task_sighand(child, &flags);
701 static int ptrace_setsiginfo(struct task_struct *child, const siginfo_t *info)
706 if (lock_task_sighand(child, &flags)) {
708 if (likely(child->last_siginfo != NULL)) {
709 *child->last_siginfo = *info;
712 unlock_task_sighand(child, &flags);
717 static int ptrace_peek_siginfo(struct task_struct *child,
721 struct ptrace_peeksiginfo_args arg;
722 struct sigpending *pending;
726 ret = copy_from_user(&arg, (void __user *) addr,
727 sizeof(struct ptrace_peeksiginfo_args));
731 if (arg.flags & ~PTRACE_PEEKSIGINFO_SHARED)
732 return -EINVAL; /* unknown flags */
737 /* Ensure arg.off fits in an unsigned long */
738 if (arg.off > ULONG_MAX)
741 if (arg.flags & PTRACE_PEEKSIGINFO_SHARED)
742 pending = &child->signal->shared_pending;
744 pending = &child->pending;
746 for (i = 0; i < arg.nr; ) {
748 unsigned long off = arg.off + i;
751 spin_lock_irq(&child->sighand->siglock);
752 list_for_each_entry(q, &pending->list, list) {
755 copy_siginfo(&info, &q->info);
759 spin_unlock_irq(&child->sighand->siglock);
761 if (!found) /* beyond the end of the list */
765 if (unlikely(in_compat_syscall())) {
766 compat_siginfo_t __user *uinfo = compat_ptr(data);
768 if (copy_siginfo_to_user32(uinfo, &info) ||
769 __put_user(info.si_code, &uinfo->si_code)) {
777 siginfo_t __user *uinfo = (siginfo_t __user *) data;
779 if (copy_siginfo_to_user(uinfo, &info) ||
780 __put_user(info.si_code, &uinfo->si_code)) {
786 data += sizeof(siginfo_t);
789 if (signal_pending(current))
801 #ifdef PTRACE_SINGLESTEP
802 #define is_singlestep(request) ((request) == PTRACE_SINGLESTEP)
804 #define is_singlestep(request) 0
807 #ifdef PTRACE_SINGLEBLOCK
808 #define is_singleblock(request) ((request) == PTRACE_SINGLEBLOCK)
810 #define is_singleblock(request) 0
814 #define is_sysemu_singlestep(request) ((request) == PTRACE_SYSEMU_SINGLESTEP)
816 #define is_sysemu_singlestep(request) 0
819 static int ptrace_resume(struct task_struct *child, long request,
824 if (!valid_signal(data))
827 if (request == PTRACE_SYSCALL)
828 set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
830 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
832 #ifdef TIF_SYSCALL_EMU
833 if (request == PTRACE_SYSEMU || request == PTRACE_SYSEMU_SINGLESTEP)
834 set_tsk_thread_flag(child, TIF_SYSCALL_EMU);
836 clear_tsk_thread_flag(child, TIF_SYSCALL_EMU);
839 if (is_singleblock(request)) {
840 if (unlikely(!arch_has_block_step()))
842 user_enable_block_step(child);
843 } else if (is_singlestep(request) || is_sysemu_singlestep(request)) {
844 if (unlikely(!arch_has_single_step()))
846 user_enable_single_step(child);
848 user_disable_single_step(child);
852 * Change ->exit_code and ->state under siglock to avoid the race
853 * with wait_task_stopped() in between; a non-zero ->exit_code will
854 * wrongly look like another report from tracee.
856 * Note that we need siglock even if ->exit_code == data and/or this
857 * status was not reported yet, the new status must not be cleared by
858 * wait_task_stopped() after resume.
860 * If data == 0 we do not care if wait_task_stopped() reports the old
861 * status and clears the code too; this can't race with the tracee, it
862 * takes siglock after resume.
864 need_siglock = data && !thread_group_empty(current);
866 spin_lock_irq(&child->sighand->siglock);
867 child->exit_code = data;
868 wake_up_state(child, __TASK_TRACED);
870 spin_unlock_irq(&child->sighand->siglock);
875 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
877 static const struct user_regset *
878 find_regset(const struct user_regset_view *view, unsigned int type)
880 const struct user_regset *regset;
883 for (n = 0; n < view->n; ++n) {
884 regset = view->regsets + n;
885 if (regset->core_note_type == type)
892 static int ptrace_regset(struct task_struct *task, int req, unsigned int type,
895 const struct user_regset_view *view = task_user_regset_view(task);
896 const struct user_regset *regset = find_regset(view, type);
899 if (!regset || (kiov->iov_len % regset->size) != 0)
902 regset_no = regset - view->regsets;
903 kiov->iov_len = min(kiov->iov_len,
904 (__kernel_size_t) (regset->n * regset->size));
906 if (req == PTRACE_GETREGSET)
907 return copy_regset_to_user(task, view, regset_no, 0,
908 kiov->iov_len, kiov->iov_base);
910 return copy_regset_from_user(task, view, regset_no, 0,
911 kiov->iov_len, kiov->iov_base);
915 * This is declared in linux/regset.h and defined in machine-dependent
916 * code. We put the export here, near the primary machine-neutral use,
917 * to ensure no machine forgets it.
919 EXPORT_SYMBOL_GPL(task_user_regset_view);
922 int ptrace_request(struct task_struct *child, long request,
923 unsigned long addr, unsigned long data)
925 bool seized = child->ptrace & PT_SEIZED;
927 siginfo_t siginfo, *si;
928 void __user *datavp = (void __user *) data;
929 unsigned long __user *datalp = datavp;
933 case PTRACE_PEEKTEXT:
934 case PTRACE_PEEKDATA:
935 return generic_ptrace_peekdata(child, addr, data);
936 case PTRACE_POKETEXT:
937 case PTRACE_POKEDATA:
938 return generic_ptrace_pokedata(child, addr, data);
940 #ifdef PTRACE_OLDSETOPTIONS
941 case PTRACE_OLDSETOPTIONS:
943 case PTRACE_SETOPTIONS:
944 ret = ptrace_setoptions(child, data);
946 case PTRACE_GETEVENTMSG:
947 ret = put_user(child->ptrace_message, datalp);
950 case PTRACE_PEEKSIGINFO:
951 ret = ptrace_peek_siginfo(child, addr, data);
954 case PTRACE_GETSIGINFO:
955 ret = ptrace_getsiginfo(child, &siginfo);
957 ret = copy_siginfo_to_user(datavp, &siginfo);
960 case PTRACE_SETSIGINFO:
961 if (copy_from_user(&siginfo, datavp, sizeof siginfo))
964 ret = ptrace_setsiginfo(child, &siginfo);
967 case PTRACE_GETSIGMASK:
968 if (addr != sizeof(sigset_t)) {
973 if (copy_to_user(datavp, &child->blocked, sizeof(sigset_t)))
980 case PTRACE_SETSIGMASK: {
983 if (addr != sizeof(sigset_t)) {
988 if (copy_from_user(&new_set, datavp, sizeof(sigset_t))) {
993 sigdelsetmask(&new_set, sigmask(SIGKILL)|sigmask(SIGSTOP));
996 * Every thread does recalc_sigpending() after resume, so
997 * retarget_shared_pending() and recalc_sigpending() are not
1000 spin_lock_irq(&child->sighand->siglock);
1001 child->blocked = new_set;
1002 spin_unlock_irq(&child->sighand->siglock);
1008 case PTRACE_INTERRUPT:
1010 * Stop tracee without any side-effect on signal or job
1011 * control. At least one trap is guaranteed to happen
1012 * after this request. If @child is already trapped, the
1013 * current trap is not disturbed and another trap will
1014 * happen after the current trap is ended with PTRACE_CONT.
1016 * The actual trap might not be PTRACE_EVENT_STOP trap but
1017 * the pending condition is cleared regardless.
1019 if (unlikely(!seized || !lock_task_sighand(child, &flags)))
1023 * INTERRUPT doesn't disturb existing trap sans one
1024 * exception. If ptracer issued LISTEN for the current
1025 * STOP, this INTERRUPT should clear LISTEN and re-trap
1028 if (likely(task_set_jobctl_pending(child, JOBCTL_TRAP_STOP)))
1029 ptrace_signal_wake_up(child, child->jobctl & JOBCTL_LISTENING);
1031 unlock_task_sighand(child, &flags);
1037 * Listen for events. Tracee must be in STOP. It's not
1038 * resumed per-se but is not considered to be in TRACED by
1039 * wait(2) or ptrace(2). If an async event (e.g. group
1040 * stop state change) happens, tracee will enter STOP trap
1041 * again. Alternatively, ptracer can issue INTERRUPT to
1042 * finish listening and re-trap tracee into STOP.
1044 if (unlikely(!seized || !lock_task_sighand(child, &flags)))
1047 si = child->last_siginfo;
1048 if (likely(si && (si->si_code >> 8) == PTRACE_EVENT_STOP)) {
1049 child->jobctl |= JOBCTL_LISTENING;
1051 * If NOTIFY is set, it means event happened between
1052 * start of this trap and now. Trigger re-trap.
1054 if (child->jobctl & JOBCTL_TRAP_NOTIFY)
1055 ptrace_signal_wake_up(child, true);
1058 unlock_task_sighand(child, &flags);
1061 case PTRACE_DETACH: /* detach a process that was attached. */
1062 ret = ptrace_detach(child, data);
1065 #ifdef CONFIG_BINFMT_ELF_FDPIC
1066 case PTRACE_GETFDPIC: {
1067 struct mm_struct *mm = get_task_mm(child);
1068 unsigned long tmp = 0;
1075 case PTRACE_GETFDPIC_EXEC:
1076 tmp = mm->context.exec_fdpic_loadmap;
1078 case PTRACE_GETFDPIC_INTERP:
1079 tmp = mm->context.interp_fdpic_loadmap;
1086 ret = put_user(tmp, datalp);
1091 #ifdef PTRACE_SINGLESTEP
1092 case PTRACE_SINGLESTEP:
1094 #ifdef PTRACE_SINGLEBLOCK
1095 case PTRACE_SINGLEBLOCK:
1097 #ifdef PTRACE_SYSEMU
1099 case PTRACE_SYSEMU_SINGLESTEP:
1101 case PTRACE_SYSCALL:
1103 return ptrace_resume(child, request, data);
1106 if (child->exit_state) /* already dead */
1108 return ptrace_resume(child, request, SIGKILL);
1110 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
1111 case PTRACE_GETREGSET:
1112 case PTRACE_SETREGSET: {
1114 struct iovec __user *uiov = datavp;
1116 if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov)))
1119 if (__get_user(kiov.iov_base, &uiov->iov_base) ||
1120 __get_user(kiov.iov_len, &uiov->iov_len))
1123 ret = ptrace_regset(child, request, addr, &kiov);
1125 ret = __put_user(kiov.iov_len, &uiov->iov_len);
1130 case PTRACE_SECCOMP_GET_FILTER:
1131 ret = seccomp_get_filter(child, addr, datavp);
1141 static struct task_struct *ptrace_get_task_struct(pid_t pid)
1143 struct task_struct *child;
1146 child = find_task_by_vpid(pid);
1148 get_task_struct(child);
1152 return ERR_PTR(-ESRCH);
1156 #ifndef arch_ptrace_attach
1157 #define arch_ptrace_attach(child) do { } while (0)
1160 SYSCALL_DEFINE4(ptrace, long, request, long, pid, unsigned long, addr,
1161 unsigned long, data)
1163 struct task_struct *child;
1166 if (request == PTRACE_TRACEME) {
1167 ret = ptrace_traceme();
1169 arch_ptrace_attach(current);
1173 child = ptrace_get_task_struct(pid);
1174 if (IS_ERR(child)) {
1175 ret = PTR_ERR(child);
1179 if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) {
1180 ret = ptrace_attach(child, request, addr, data);
1182 * Some architectures need to do book-keeping after
1186 arch_ptrace_attach(child);
1187 goto out_put_task_struct;
1190 ret = ptrace_check_attach(child, request == PTRACE_KILL ||
1191 request == PTRACE_INTERRUPT);
1193 goto out_put_task_struct;
1195 ret = arch_ptrace(child, request, addr, data);
1196 if (ret || request != PTRACE_DETACH)
1197 ptrace_unfreeze_traced(child);
1199 out_put_task_struct:
1200 put_task_struct(child);
1205 int generic_ptrace_peekdata(struct task_struct *tsk, unsigned long addr,
1211 copied = ptrace_access_vm(tsk, addr, &tmp, sizeof(tmp), FOLL_FORCE);
1212 if (copied != sizeof(tmp))
1214 return put_user(tmp, (unsigned long __user *)data);
1217 int generic_ptrace_pokedata(struct task_struct *tsk, unsigned long addr,
1222 copied = ptrace_access_vm(tsk, addr, &data, sizeof(data),
1223 FOLL_FORCE | FOLL_WRITE);
1224 return (copied == sizeof(data)) ? 0 : -EIO;
1227 #if defined CONFIG_COMPAT
1229 int compat_ptrace_request(struct task_struct *child, compat_long_t request,
1230 compat_ulong_t addr, compat_ulong_t data)
1232 compat_ulong_t __user *datap = compat_ptr(data);
1233 compat_ulong_t word;
1238 case PTRACE_PEEKTEXT:
1239 case PTRACE_PEEKDATA:
1240 ret = ptrace_access_vm(child, addr, &word, sizeof(word),
1242 if (ret != sizeof(word))
1245 ret = put_user(word, datap);
1248 case PTRACE_POKETEXT:
1249 case PTRACE_POKEDATA:
1250 ret = ptrace_access_vm(child, addr, &data, sizeof(data),
1251 FOLL_FORCE | FOLL_WRITE);
1252 ret = (ret != sizeof(data) ? -EIO : 0);
1255 case PTRACE_GETEVENTMSG:
1256 ret = put_user((compat_ulong_t) child->ptrace_message, datap);
1259 case PTRACE_GETSIGINFO:
1260 ret = ptrace_getsiginfo(child, &siginfo);
1262 ret = copy_siginfo_to_user32(
1263 (struct compat_siginfo __user *) datap,
1267 case PTRACE_SETSIGINFO:
1268 memset(&siginfo, 0, sizeof siginfo);
1269 if (copy_siginfo_from_user32(
1270 &siginfo, (struct compat_siginfo __user *) datap))
1273 ret = ptrace_setsiginfo(child, &siginfo);
1275 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
1276 case PTRACE_GETREGSET:
1277 case PTRACE_SETREGSET:
1280 struct compat_iovec __user *uiov =
1281 (struct compat_iovec __user *) datap;
1285 if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov)))
1288 if (__get_user(ptr, &uiov->iov_base) ||
1289 __get_user(len, &uiov->iov_len))
1292 kiov.iov_base = compat_ptr(ptr);
1295 ret = ptrace_regset(child, request, addr, &kiov);
1297 ret = __put_user(kiov.iov_len, &uiov->iov_len);
1303 ret = ptrace_request(child, request, addr, data);
1309 COMPAT_SYSCALL_DEFINE4(ptrace, compat_long_t, request, compat_long_t, pid,
1310 compat_long_t, addr, compat_long_t, data)
1312 struct task_struct *child;
1315 if (request == PTRACE_TRACEME) {
1316 ret = ptrace_traceme();
1320 child = ptrace_get_task_struct(pid);
1321 if (IS_ERR(child)) {
1322 ret = PTR_ERR(child);
1326 if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) {
1327 ret = ptrace_attach(child, request, addr, data);
1329 * Some architectures need to do book-keeping after
1333 arch_ptrace_attach(child);
1334 goto out_put_task_struct;
1337 ret = ptrace_check_attach(child, request == PTRACE_KILL ||
1338 request == PTRACE_INTERRUPT);
1340 ret = compat_arch_ptrace(child, request, addr, data);
1341 if (ret || request != PTRACE_DETACH)
1342 ptrace_unfreeze_traced(child);
1345 out_put_task_struct:
1346 put_task_struct(child);
1350 #endif /* CONFIG_COMPAT */