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>
32 * ptrace a task: make the debugger its new parent and
33 * move it to the ptrace list.
35 * Must be called with the tasklist lock write-held.
37 void __ptrace_link(struct task_struct *child, struct task_struct *new_parent)
39 BUG_ON(!list_empty(&child->ptrace_entry));
40 list_add(&child->ptrace_entry, &new_parent->ptraced);
41 child->parent = new_parent;
45 * __ptrace_unlink - unlink ptracee and restore its execution state
46 * @child: ptracee to be unlinked
48 * Remove @child from the ptrace list, move it back to the original parent,
49 * and restore the execution state so that it conforms to the group stop
52 * Unlinking can happen via two paths - explicit PTRACE_DETACH or ptracer
53 * exiting. For PTRACE_DETACH, unless the ptracee has been killed between
54 * ptrace_check_attach() and here, it's guaranteed to be in TASK_TRACED.
55 * If the ptracer is exiting, the ptracee can be in any state.
57 * After detach, the ptracee should be in a state which conforms to the
58 * group stop. If the group is stopped or in the process of stopping, the
59 * ptracee should be put into TASK_STOPPED; otherwise, it should be woken
60 * up from TASK_TRACED.
62 * If the ptracee is in TASK_TRACED and needs to be moved to TASK_STOPPED,
63 * it goes through TRACED -> RUNNING -> STOPPED transition which is similar
64 * to but in the opposite direction of what happens while attaching to a
65 * stopped task. However, in this direction, the intermediate RUNNING
66 * state is not hidden even from the current ptracer and if it immediately
67 * re-attaches and performs a WNOHANG wait(2), it may fail.
70 * write_lock_irq(tasklist_lock)
72 void __ptrace_unlink(struct task_struct *child)
74 BUG_ON(!child->ptrace);
77 child->parent = child->real_parent;
78 list_del_init(&child->ptrace_entry);
80 spin_lock(&child->sighand->siglock);
83 * Clear all pending traps and TRAPPING. TRAPPING should be
84 * cleared regardless of JOBCTL_STOP_PENDING. Do it explicitly.
86 task_clear_jobctl_pending(child, JOBCTL_TRAP_MASK);
87 task_clear_jobctl_trapping(child);
90 * Reinstate JOBCTL_STOP_PENDING if group stop is in effect and
93 if (!(child->flags & PF_EXITING) &&
94 (child->signal->flags & SIGNAL_STOP_STOPPED ||
95 child->signal->group_stop_count)) {
96 child->jobctl |= JOBCTL_STOP_PENDING;
99 * This is only possible if this thread was cloned by the
100 * traced task running in the stopped group, set the signal
101 * for the future reports.
102 * FIXME: we should change ptrace_init_task() to handle this
105 if (!(child->jobctl & JOBCTL_STOP_SIGMASK))
106 child->jobctl |= SIGSTOP;
110 * If transition to TASK_STOPPED is pending or in TASK_TRACED, kick
111 * @child in the butt. Note that @resume should be used iff @child
112 * is in TASK_TRACED; otherwise, we might unduly disrupt
113 * TASK_KILLABLE sleeps.
115 if (child->jobctl & JOBCTL_STOP_PENDING || task_is_traced(child))
116 ptrace_signal_wake_up(child, true);
118 spin_unlock(&child->sighand->siglock);
121 /* Ensure that nothing can wake it up, even SIGKILL */
122 static bool ptrace_freeze_traced(struct task_struct *task)
126 /* Lockless, nobody but us can set this flag */
127 if (task->jobctl & JOBCTL_LISTENING)
130 spin_lock_irq(&task->sighand->siglock);
131 if (task_is_traced(task) && !__fatal_signal_pending(task)) {
134 raw_spin_lock_irqsave(&task->pi_lock, flags);
135 if (task->state & __TASK_TRACED)
136 task->state = __TASK_TRACED;
138 task->saved_state = __TASK_TRACED;
139 raw_spin_unlock_irqrestore(&task->pi_lock, flags);
142 spin_unlock_irq(&task->sighand->siglock);
147 static void ptrace_unfreeze_traced(struct task_struct *task)
149 if (task->state != __TASK_TRACED)
152 WARN_ON(!task->ptrace || task->parent != current);
154 spin_lock_irq(&task->sighand->siglock);
155 if (__fatal_signal_pending(task))
156 wake_up_state(task, __TASK_TRACED);
158 task->state = TASK_TRACED;
159 spin_unlock_irq(&task->sighand->siglock);
163 * ptrace_check_attach - check whether ptracee is ready for ptrace operation
164 * @child: ptracee to check for
165 * @ignore_state: don't check whether @child is currently %TASK_TRACED
167 * Check whether @child is being ptraced by %current and ready for further
168 * ptrace operations. If @ignore_state is %false, @child also should be in
169 * %TASK_TRACED state and on return the child is guaranteed to be traced
170 * and not executing. If @ignore_state is %true, @child can be in any
174 * Grabs and releases tasklist_lock and @child->sighand->siglock.
177 * 0 on success, -ESRCH if %child is not ready.
179 static int ptrace_check_attach(struct task_struct *child, bool ignore_state)
184 * We take the read lock around doing both checks to close a
185 * possible race where someone else was tracing our child and
186 * detached between these two checks. After this locked check,
187 * we are sure that this is our traced child and that can only
188 * be changed by us so it's not changing right after this.
190 read_lock(&tasklist_lock);
191 if (child->ptrace && child->parent == current) {
192 WARN_ON(child->state == __TASK_TRACED);
194 * child->sighand can't be NULL, release_task()
195 * does ptrace_unlink() before __exit_signal().
197 if (ignore_state || ptrace_freeze_traced(child))
200 read_unlock(&tasklist_lock);
202 if (!ret && !ignore_state) {
203 if (!wait_task_inactive(child, __TASK_TRACED)) {
205 * This can only happen if may_ptrace_stop() fails and
206 * ptrace_stop() changes ->state back to TASK_RUNNING,
207 * so we should not worry about leaking __TASK_TRACED.
209 WARN_ON(child->state == __TASK_TRACED);
217 static int ptrace_has_cap(struct user_namespace *ns, unsigned int mode)
219 if (mode & PTRACE_MODE_NOAUDIT)
220 return has_ns_capability_noaudit(current, ns, CAP_SYS_PTRACE);
222 return has_ns_capability(current, ns, CAP_SYS_PTRACE);
225 /* Returns 0 on success, -errno on denial. */
226 static int __ptrace_may_access(struct task_struct *task, unsigned int mode)
228 const struct cred *cred = current_cred(), *tcred;
233 if (!(mode & PTRACE_MODE_FSCREDS) == !(mode & PTRACE_MODE_REALCREDS)) {
234 WARN(1, "denying ptrace access check without PTRACE_MODE_*CREDS\n");
238 /* May we inspect the given task?
239 * This check is used both for attaching with ptrace
240 * and for allowing access to sensitive information in /proc.
242 * ptrace_attach denies several cases that /proc allows
243 * because setting up the necessary parent/child relationship
244 * or halting the specified task is impossible.
247 /* Don't let security modules deny introspection */
248 if (same_thread_group(task, current))
251 if (mode & PTRACE_MODE_FSCREDS) {
252 caller_uid = cred->fsuid;
253 caller_gid = cred->fsgid;
256 * Using the euid would make more sense here, but something
257 * in userland might rely on the old behavior, and this
258 * shouldn't be a security problem since
259 * PTRACE_MODE_REALCREDS implies that the caller explicitly
260 * used a syscall that requests access to another process
261 * (and not a filesystem syscall to procfs).
263 caller_uid = cred->uid;
264 caller_gid = cred->gid;
266 tcred = __task_cred(task);
267 if (uid_eq(caller_uid, tcred->euid) &&
268 uid_eq(caller_uid, tcred->suid) &&
269 uid_eq(caller_uid, tcred->uid) &&
270 gid_eq(caller_gid, tcred->egid) &&
271 gid_eq(caller_gid, tcred->sgid) &&
272 gid_eq(caller_gid, tcred->gid))
274 if (ptrace_has_cap(tcred->user_ns, mode))
282 dumpable = get_dumpable(task->mm);
284 if (dumpable != SUID_DUMP_USER &&
285 !ptrace_has_cap(__task_cred(task)->user_ns, mode)) {
291 return security_ptrace_access_check(task, mode);
294 bool ptrace_may_access(struct task_struct *task, unsigned int mode)
298 err = __ptrace_may_access(task, mode);
303 static int ptrace_attach(struct task_struct *task, long request,
307 bool seize = (request == PTRACE_SEIZE);
314 if (flags & ~(unsigned long)PTRACE_O_MASK)
316 flags = PT_PTRACED | PT_SEIZED | (flags << PT_OPT_FLAG_SHIFT);
324 if (unlikely(task->flags & PF_KTHREAD))
326 if (same_thread_group(task, current))
330 * Protect exec's credential calculations against our interference;
331 * SUID, SGID and LSM creds get determined differently
334 retval = -ERESTARTNOINTR;
335 if (mutex_lock_interruptible(&task->signal->cred_guard_mutex))
339 retval = __ptrace_may_access(task, PTRACE_MODE_ATTACH_REALCREDS);
344 write_lock_irq(&tasklist_lock);
346 if (unlikely(task->exit_state))
347 goto unlock_tasklist;
349 goto unlock_tasklist;
354 if (ns_capable(__task_cred(task)->user_ns, CAP_SYS_PTRACE))
355 flags |= PT_PTRACE_CAP;
357 task->ptrace = flags;
359 __ptrace_link(task, current);
361 /* SEIZE doesn't trap tracee on attach */
363 send_sig_info(SIGSTOP, SEND_SIG_FORCED, task);
365 spin_lock(&task->sighand->siglock);
368 * If the task is already STOPPED, set JOBCTL_TRAP_STOP and
369 * TRAPPING, and kick it so that it transits to TRACED. TRAPPING
370 * will be cleared if the child completes the transition or any
371 * event which clears the group stop states happens. We'll wait
372 * for the transition to complete before returning from this
375 * This hides STOPPED -> RUNNING -> TRACED transition from the
376 * attaching thread but a different thread in the same group can
377 * still observe the transient RUNNING state. IOW, if another
378 * thread's WNOHANG wait(2) on the stopped tracee races against
379 * ATTACH, the wait(2) may fail due to the transient RUNNING.
381 * The following task_is_stopped() test is safe as both transitions
382 * in and out of STOPPED are protected by siglock.
384 if (task_is_stopped(task) &&
385 task_set_jobctl_pending(task, JOBCTL_TRAP_STOP | JOBCTL_TRAPPING))
386 signal_wake_up_state(task, __TASK_STOPPED);
388 spin_unlock(&task->sighand->siglock);
392 write_unlock_irq(&tasklist_lock);
394 mutex_unlock(&task->signal->cred_guard_mutex);
397 wait_on_bit(&task->jobctl, JOBCTL_TRAPPING_BIT,
398 TASK_UNINTERRUPTIBLE);
399 proc_ptrace_connector(task, PTRACE_ATTACH);
406 * ptrace_traceme -- helper for PTRACE_TRACEME
408 * Performs checks and sets PT_PTRACED.
409 * Should be used by all ptrace implementations for PTRACE_TRACEME.
411 static int ptrace_traceme(void)
415 write_lock_irq(&tasklist_lock);
416 /* Are we already being traced? */
417 if (!current->ptrace) {
418 ret = security_ptrace_traceme(current->parent);
420 * Check PF_EXITING to ensure ->real_parent has not passed
421 * exit_ptrace(). Otherwise we don't report the error but
422 * pretend ->real_parent untraces us right after return.
424 if (!ret && !(current->real_parent->flags & PF_EXITING)) {
425 current->ptrace = PT_PTRACED;
426 __ptrace_link(current, current->real_parent);
429 write_unlock_irq(&tasklist_lock);
435 * Called with irqs disabled, returns true if childs should reap themselves.
437 static int ignoring_children(struct sighand_struct *sigh)
440 spin_lock(&sigh->siglock);
441 ret = (sigh->action[SIGCHLD-1].sa.sa_handler == SIG_IGN) ||
442 (sigh->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT);
443 spin_unlock(&sigh->siglock);
448 * Called with tasklist_lock held for writing.
449 * Unlink a traced task, and clean it up if it was a traced zombie.
450 * Return true if it needs to be reaped with release_task().
451 * (We can't call release_task() here because we already hold tasklist_lock.)
453 * If it's a zombie, our attachedness prevented normal parent notification
454 * or self-reaping. Do notification now if it would have happened earlier.
455 * If it should reap itself, return true.
457 * If it's our own child, there is no notification to do. But if our normal
458 * children self-reap, then this child was prevented by ptrace and we must
459 * reap it now, in that case we must also wake up sub-threads sleeping in
462 static bool __ptrace_detach(struct task_struct *tracer, struct task_struct *p)
468 if (p->exit_state != EXIT_ZOMBIE)
471 dead = !thread_group_leader(p);
473 if (!dead && thread_group_empty(p)) {
474 if (!same_thread_group(p->real_parent, tracer))
475 dead = do_notify_parent(p, p->exit_signal);
476 else if (ignoring_children(tracer->sighand)) {
477 __wake_up_parent(p, tracer);
481 /* Mark it as in the process of being reaped. */
483 p->exit_state = EXIT_DEAD;
487 static int ptrace_detach(struct task_struct *child, unsigned int data)
489 if (!valid_signal(data))
492 /* Architecture-specific hardware disable .. */
493 ptrace_disable(child);
494 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
496 write_lock_irq(&tasklist_lock);
498 * We rely on ptrace_freeze_traced(). It can't be killed and
499 * untraced by another thread, it can't be a zombie.
501 WARN_ON(!child->ptrace || child->exit_state);
503 * tasklist_lock avoids the race with wait_task_stopped(), see
504 * the comment in ptrace_resume().
506 child->exit_code = data;
507 __ptrace_detach(current, child);
508 write_unlock_irq(&tasklist_lock);
510 proc_ptrace_connector(child, PTRACE_DETACH);
516 * Detach all tasks we were using ptrace on. Called with tasklist held
519 void exit_ptrace(struct task_struct *tracer, struct list_head *dead)
521 struct task_struct *p, *n;
523 list_for_each_entry_safe(p, n, &tracer->ptraced, ptrace_entry) {
524 if (unlikely(p->ptrace & PT_EXITKILL))
525 send_sig_info(SIGKILL, SEND_SIG_FORCED, p);
527 if (__ptrace_detach(tracer, p))
528 list_add(&p->ptrace_entry, dead);
532 int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len)
538 int this_len, retval;
540 this_len = (len > sizeof(buf)) ? sizeof(buf) : len;
541 retval = access_process_vm(tsk, src, buf, this_len, 0);
547 if (copy_to_user(dst, buf, retval))
557 int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len)
563 int this_len, retval;
565 this_len = (len > sizeof(buf)) ? sizeof(buf) : len;
566 if (copy_from_user(buf, src, this_len))
568 retval = access_process_vm(tsk, dst, buf, this_len, 1);
582 static int ptrace_setoptions(struct task_struct *child, unsigned long data)
586 if (data & ~(unsigned long)PTRACE_O_MASK)
589 if (unlikely(data & PTRACE_O_SUSPEND_SECCOMP)) {
590 if (!config_enabled(CONFIG_CHECKPOINT_RESTORE) ||
591 !config_enabled(CONFIG_SECCOMP))
594 if (!capable(CAP_SYS_ADMIN))
597 if (seccomp_mode(¤t->seccomp) != SECCOMP_MODE_DISABLED ||
598 current->ptrace & PT_SUSPEND_SECCOMP)
602 /* Avoid intermediate state when all opts are cleared */
603 flags = child->ptrace;
604 flags &= ~(PTRACE_O_MASK << PT_OPT_FLAG_SHIFT);
605 flags |= (data << PT_OPT_FLAG_SHIFT);
606 child->ptrace = flags;
611 static int ptrace_getsiginfo(struct task_struct *child, siginfo_t *info)
616 if (lock_task_sighand(child, &flags)) {
618 if (likely(child->last_siginfo != NULL)) {
619 *info = *child->last_siginfo;
622 unlock_task_sighand(child, &flags);
627 static int ptrace_setsiginfo(struct task_struct *child, const siginfo_t *info)
632 if (lock_task_sighand(child, &flags)) {
634 if (likely(child->last_siginfo != NULL)) {
635 *child->last_siginfo = *info;
638 unlock_task_sighand(child, &flags);
643 static int ptrace_peek_siginfo(struct task_struct *child,
647 struct ptrace_peeksiginfo_args arg;
648 struct sigpending *pending;
652 ret = copy_from_user(&arg, (void __user *) addr,
653 sizeof(struct ptrace_peeksiginfo_args));
657 if (arg.flags & ~PTRACE_PEEKSIGINFO_SHARED)
658 return -EINVAL; /* unknown flags */
663 if (arg.flags & PTRACE_PEEKSIGINFO_SHARED)
664 pending = &child->signal->shared_pending;
666 pending = &child->pending;
668 for (i = 0; i < arg.nr; ) {
670 s32 off = arg.off + i;
672 spin_lock_irq(&child->sighand->siglock);
673 list_for_each_entry(q, &pending->list, list) {
675 copy_siginfo(&info, &q->info);
679 spin_unlock_irq(&child->sighand->siglock);
681 if (off >= 0) /* beyond the end of the list */
685 if (unlikely(is_compat_task())) {
686 compat_siginfo_t __user *uinfo = compat_ptr(data);
688 if (copy_siginfo_to_user32(uinfo, &info) ||
689 __put_user(info.si_code, &uinfo->si_code)) {
697 siginfo_t __user *uinfo = (siginfo_t __user *) data;
699 if (copy_siginfo_to_user(uinfo, &info) ||
700 __put_user(info.si_code, &uinfo->si_code)) {
706 data += sizeof(siginfo_t);
709 if (signal_pending(current))
721 #ifdef PTRACE_SINGLESTEP
722 #define is_singlestep(request) ((request) == PTRACE_SINGLESTEP)
724 #define is_singlestep(request) 0
727 #ifdef PTRACE_SINGLEBLOCK
728 #define is_singleblock(request) ((request) == PTRACE_SINGLEBLOCK)
730 #define is_singleblock(request) 0
734 #define is_sysemu_singlestep(request) ((request) == PTRACE_SYSEMU_SINGLESTEP)
736 #define is_sysemu_singlestep(request) 0
739 static int ptrace_resume(struct task_struct *child, long request,
744 if (!valid_signal(data))
747 if (request == PTRACE_SYSCALL)
748 set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
750 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
752 #ifdef TIF_SYSCALL_EMU
753 if (request == PTRACE_SYSEMU || request == PTRACE_SYSEMU_SINGLESTEP)
754 set_tsk_thread_flag(child, TIF_SYSCALL_EMU);
756 clear_tsk_thread_flag(child, TIF_SYSCALL_EMU);
759 if (is_singleblock(request)) {
760 if (unlikely(!arch_has_block_step()))
762 user_enable_block_step(child);
763 } else if (is_singlestep(request) || is_sysemu_singlestep(request)) {
764 if (unlikely(!arch_has_single_step()))
766 user_enable_single_step(child);
768 user_disable_single_step(child);
772 * Change ->exit_code and ->state under siglock to avoid the race
773 * with wait_task_stopped() in between; a non-zero ->exit_code will
774 * wrongly look like another report from tracee.
776 * Note that we need siglock even if ->exit_code == data and/or this
777 * status was not reported yet, the new status must not be cleared by
778 * wait_task_stopped() after resume.
780 * If data == 0 we do not care if wait_task_stopped() reports the old
781 * status and clears the code too; this can't race with the tracee, it
782 * takes siglock after resume.
784 need_siglock = data && !thread_group_empty(current);
786 spin_lock_irq(&child->sighand->siglock);
787 child->exit_code = data;
788 wake_up_state(child, __TASK_TRACED);
790 spin_unlock_irq(&child->sighand->siglock);
795 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
797 static const struct user_regset *
798 find_regset(const struct user_regset_view *view, unsigned int type)
800 const struct user_regset *regset;
803 for (n = 0; n < view->n; ++n) {
804 regset = view->regsets + n;
805 if (regset->core_note_type == type)
812 static int ptrace_regset(struct task_struct *task, int req, unsigned int type,
815 const struct user_regset_view *view = task_user_regset_view(task);
816 const struct user_regset *regset = find_regset(view, type);
819 if (!regset || (kiov->iov_len % regset->size) != 0)
822 regset_no = regset - view->regsets;
823 kiov->iov_len = min(kiov->iov_len,
824 (__kernel_size_t) (regset->n * regset->size));
826 if (req == PTRACE_GETREGSET)
827 return copy_regset_to_user(task, view, regset_no, 0,
828 kiov->iov_len, kiov->iov_base);
830 return copy_regset_from_user(task, view, regset_no, 0,
831 kiov->iov_len, kiov->iov_base);
835 * This is declared in linux/regset.h and defined in machine-dependent
836 * code. We put the export here, near the primary machine-neutral use,
837 * to ensure no machine forgets it.
839 EXPORT_SYMBOL_GPL(task_user_regset_view);
842 int ptrace_request(struct task_struct *child, long request,
843 unsigned long addr, unsigned long data)
845 bool seized = child->ptrace & PT_SEIZED;
847 siginfo_t siginfo, *si;
848 void __user *datavp = (void __user *) data;
849 unsigned long __user *datalp = datavp;
853 case PTRACE_PEEKTEXT:
854 case PTRACE_PEEKDATA:
855 return generic_ptrace_peekdata(child, addr, data);
856 case PTRACE_POKETEXT:
857 case PTRACE_POKEDATA:
858 return generic_ptrace_pokedata(child, addr, data);
860 #ifdef PTRACE_OLDSETOPTIONS
861 case PTRACE_OLDSETOPTIONS:
863 case PTRACE_SETOPTIONS:
864 ret = ptrace_setoptions(child, data);
866 case PTRACE_GETEVENTMSG:
867 ret = put_user(child->ptrace_message, datalp);
870 case PTRACE_PEEKSIGINFO:
871 ret = ptrace_peek_siginfo(child, addr, data);
874 case PTRACE_GETSIGINFO:
875 ret = ptrace_getsiginfo(child, &siginfo);
877 ret = copy_siginfo_to_user(datavp, &siginfo);
880 case PTRACE_SETSIGINFO:
881 if (copy_from_user(&siginfo, datavp, sizeof siginfo))
884 ret = ptrace_setsiginfo(child, &siginfo);
887 case PTRACE_GETSIGMASK:
888 if (addr != sizeof(sigset_t)) {
893 if (copy_to_user(datavp, &child->blocked, sizeof(sigset_t)))
900 case PTRACE_SETSIGMASK: {
903 if (addr != sizeof(sigset_t)) {
908 if (copy_from_user(&new_set, datavp, sizeof(sigset_t))) {
913 sigdelsetmask(&new_set, sigmask(SIGKILL)|sigmask(SIGSTOP));
916 * Every thread does recalc_sigpending() after resume, so
917 * retarget_shared_pending() and recalc_sigpending() are not
920 spin_lock_irq(&child->sighand->siglock);
921 child->blocked = new_set;
922 spin_unlock_irq(&child->sighand->siglock);
928 case PTRACE_INTERRUPT:
930 * Stop tracee without any side-effect on signal or job
931 * control. At least one trap is guaranteed to happen
932 * after this request. If @child is already trapped, the
933 * current trap is not disturbed and another trap will
934 * happen after the current trap is ended with PTRACE_CONT.
936 * The actual trap might not be PTRACE_EVENT_STOP trap but
937 * the pending condition is cleared regardless.
939 if (unlikely(!seized || !lock_task_sighand(child, &flags)))
943 * INTERRUPT doesn't disturb existing trap sans one
944 * exception. If ptracer issued LISTEN for the current
945 * STOP, this INTERRUPT should clear LISTEN and re-trap
948 if (likely(task_set_jobctl_pending(child, JOBCTL_TRAP_STOP)))
949 ptrace_signal_wake_up(child, child->jobctl & JOBCTL_LISTENING);
951 unlock_task_sighand(child, &flags);
957 * Listen for events. Tracee must be in STOP. It's not
958 * resumed per-se but is not considered to be in TRACED by
959 * wait(2) or ptrace(2). If an async event (e.g. group
960 * stop state change) happens, tracee will enter STOP trap
961 * again. Alternatively, ptracer can issue INTERRUPT to
962 * finish listening and re-trap tracee into STOP.
964 if (unlikely(!seized || !lock_task_sighand(child, &flags)))
967 si = child->last_siginfo;
968 if (likely(si && (si->si_code >> 8) == PTRACE_EVENT_STOP)) {
969 child->jobctl |= JOBCTL_LISTENING;
971 * If NOTIFY is set, it means event happened between
972 * start of this trap and now. Trigger re-trap.
974 if (child->jobctl & JOBCTL_TRAP_NOTIFY)
975 ptrace_signal_wake_up(child, true);
978 unlock_task_sighand(child, &flags);
981 case PTRACE_DETACH: /* detach a process that was attached. */
982 ret = ptrace_detach(child, data);
985 #ifdef CONFIG_BINFMT_ELF_FDPIC
986 case PTRACE_GETFDPIC: {
987 struct mm_struct *mm = get_task_mm(child);
988 unsigned long tmp = 0;
995 case PTRACE_GETFDPIC_EXEC:
996 tmp = mm->context.exec_fdpic_loadmap;
998 case PTRACE_GETFDPIC_INTERP:
999 tmp = mm->context.interp_fdpic_loadmap;
1006 ret = put_user(tmp, datalp);
1011 #ifdef PTRACE_SINGLESTEP
1012 case PTRACE_SINGLESTEP:
1014 #ifdef PTRACE_SINGLEBLOCK
1015 case PTRACE_SINGLEBLOCK:
1017 #ifdef PTRACE_SYSEMU
1019 case PTRACE_SYSEMU_SINGLESTEP:
1021 case PTRACE_SYSCALL:
1023 return ptrace_resume(child, request, data);
1026 if (child->exit_state) /* already dead */
1028 return ptrace_resume(child, request, SIGKILL);
1030 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
1031 case PTRACE_GETREGSET:
1032 case PTRACE_SETREGSET: {
1034 struct iovec __user *uiov = datavp;
1036 if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov)))
1039 if (__get_user(kiov.iov_base, &uiov->iov_base) ||
1040 __get_user(kiov.iov_len, &uiov->iov_len))
1043 ret = ptrace_regset(child, request, addr, &kiov);
1045 ret = __put_user(kiov.iov_len, &uiov->iov_len);
1050 case PTRACE_SECCOMP_GET_FILTER:
1051 ret = seccomp_get_filter(child, addr, datavp);
1061 static struct task_struct *ptrace_get_task_struct(pid_t pid)
1063 struct task_struct *child;
1066 child = find_task_by_vpid(pid);
1068 get_task_struct(child);
1072 return ERR_PTR(-ESRCH);
1076 #ifndef arch_ptrace_attach
1077 #define arch_ptrace_attach(child) do { } while (0)
1080 SYSCALL_DEFINE4(ptrace, long, request, long, pid, unsigned long, addr,
1081 unsigned long, data)
1083 struct task_struct *child;
1086 if (request == PTRACE_TRACEME) {
1087 ret = ptrace_traceme();
1089 arch_ptrace_attach(current);
1093 child = ptrace_get_task_struct(pid);
1094 if (IS_ERR(child)) {
1095 ret = PTR_ERR(child);
1099 if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) {
1100 ret = ptrace_attach(child, request, addr, data);
1102 * Some architectures need to do book-keeping after
1106 arch_ptrace_attach(child);
1107 goto out_put_task_struct;
1110 ret = ptrace_check_attach(child, request == PTRACE_KILL ||
1111 request == PTRACE_INTERRUPT);
1113 goto out_put_task_struct;
1115 ret = arch_ptrace(child, request, addr, data);
1116 if (ret || request != PTRACE_DETACH)
1117 ptrace_unfreeze_traced(child);
1119 out_put_task_struct:
1120 put_task_struct(child);
1125 int generic_ptrace_peekdata(struct task_struct *tsk, unsigned long addr,
1131 copied = access_process_vm(tsk, addr, &tmp, sizeof(tmp), 0);
1132 if (copied != sizeof(tmp))
1134 return put_user(tmp, (unsigned long __user *)data);
1137 int generic_ptrace_pokedata(struct task_struct *tsk, unsigned long addr,
1142 copied = access_process_vm(tsk, addr, &data, sizeof(data), 1);
1143 return (copied == sizeof(data)) ? 0 : -EIO;
1146 #if defined CONFIG_COMPAT
1148 int compat_ptrace_request(struct task_struct *child, compat_long_t request,
1149 compat_ulong_t addr, compat_ulong_t data)
1151 compat_ulong_t __user *datap = compat_ptr(data);
1152 compat_ulong_t word;
1157 case PTRACE_PEEKTEXT:
1158 case PTRACE_PEEKDATA:
1159 ret = access_process_vm(child, addr, &word, sizeof(word), 0);
1160 if (ret != sizeof(word))
1163 ret = put_user(word, datap);
1166 case PTRACE_POKETEXT:
1167 case PTRACE_POKEDATA:
1168 ret = access_process_vm(child, addr, &data, sizeof(data), 1);
1169 ret = (ret != sizeof(data) ? -EIO : 0);
1172 case PTRACE_GETEVENTMSG:
1173 ret = put_user((compat_ulong_t) child->ptrace_message, datap);
1176 case PTRACE_GETSIGINFO:
1177 ret = ptrace_getsiginfo(child, &siginfo);
1179 ret = copy_siginfo_to_user32(
1180 (struct compat_siginfo __user *) datap,
1184 case PTRACE_SETSIGINFO:
1185 memset(&siginfo, 0, sizeof siginfo);
1186 if (copy_siginfo_from_user32(
1187 &siginfo, (struct compat_siginfo __user *) datap))
1190 ret = ptrace_setsiginfo(child, &siginfo);
1192 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
1193 case PTRACE_GETREGSET:
1194 case PTRACE_SETREGSET:
1197 struct compat_iovec __user *uiov =
1198 (struct compat_iovec __user *) datap;
1202 if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov)))
1205 if (__get_user(ptr, &uiov->iov_base) ||
1206 __get_user(len, &uiov->iov_len))
1209 kiov.iov_base = compat_ptr(ptr);
1212 ret = ptrace_regset(child, request, addr, &kiov);
1214 ret = __put_user(kiov.iov_len, &uiov->iov_len);
1220 ret = ptrace_request(child, request, addr, data);
1226 COMPAT_SYSCALL_DEFINE4(ptrace, compat_long_t, request, compat_long_t, pid,
1227 compat_long_t, addr, compat_long_t, data)
1229 struct task_struct *child;
1232 if (request == PTRACE_TRACEME) {
1233 ret = ptrace_traceme();
1237 child = ptrace_get_task_struct(pid);
1238 if (IS_ERR(child)) {
1239 ret = PTR_ERR(child);
1243 if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) {
1244 ret = ptrace_attach(child, request, addr, data);
1246 * Some architectures need to do book-keeping after
1250 arch_ptrace_attach(child);
1251 goto out_put_task_struct;
1254 ret = ptrace_check_attach(child, request == PTRACE_KILL ||
1255 request == PTRACE_INTERRUPT);
1257 ret = compat_arch_ptrace(child, request, addr, data);
1258 if (ret || request != PTRACE_DETACH)
1259 ptrace_unfreeze_traced(child);
1262 out_put_task_struct:
1263 put_task_struct(child);
1267 #endif /* CONFIG_COMPAT */