1 // SPDX-License-Identifier: GPL-2.0-only
3 * linux/kernel/ptrace.c
5 * (C) Copyright 1999 Linus Torvalds
7 * Common interfaces for "ptrace()" which we do not want
8 * to continually duplicate across every architecture.
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>
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>
36 * Access another process' address space via ptrace.
37 * Source/target buffer must be kernel space,
38 * Do not walk the page table directly, use get_user_pages
40 int ptrace_access_vm(struct task_struct *tsk, unsigned long addr,
41 void *buf, int len, unsigned int gup_flags)
46 mm = get_task_mm(tsk);
51 (current != tsk->parent) ||
52 ((get_dumpable(mm) != SUID_DUMP_USER) &&
53 !ptracer_capable(tsk, mm->user_ns))) {
58 ret = __access_remote_vm(tsk, mm, addr, buf, len, gup_flags);
65 void __ptrace_link(struct task_struct *child, struct task_struct *new_parent,
66 const struct cred *ptracer_cred)
68 BUG_ON(!list_empty(&child->ptrace_entry));
69 list_add(&child->ptrace_entry, &new_parent->ptraced);
70 child->parent = new_parent;
71 child->ptracer_cred = get_cred(ptracer_cred);
75 * ptrace a task: make the debugger its new parent and
76 * move it to the ptrace list.
78 * Must be called with the tasklist lock write-held.
80 static void ptrace_link(struct task_struct *child, struct task_struct *new_parent)
83 __ptrace_link(child, new_parent, __task_cred(new_parent));
88 * __ptrace_unlink - unlink ptracee and restore its execution state
89 * @child: ptracee to be unlinked
91 * Remove @child from the ptrace list, move it back to the original parent,
92 * and restore the execution state so that it conforms to the group stop
95 * Unlinking can happen via two paths - explicit PTRACE_DETACH or ptracer
96 * exiting. For PTRACE_DETACH, unless the ptracee has been killed between
97 * ptrace_check_attach() and here, it's guaranteed to be in TASK_TRACED.
98 * If the ptracer is exiting, the ptracee can be in any state.
100 * After detach, the ptracee should be in a state which conforms to the
101 * group stop. If the group is stopped or in the process of stopping, the
102 * ptracee should be put into TASK_STOPPED; otherwise, it should be woken
103 * up from TASK_TRACED.
105 * If the ptracee is in TASK_TRACED and needs to be moved to TASK_STOPPED,
106 * it goes through TRACED -> RUNNING -> STOPPED transition which is similar
107 * to but in the opposite direction of what happens while attaching to a
108 * stopped task. However, in this direction, the intermediate RUNNING
109 * state is not hidden even from the current ptracer and if it immediately
110 * re-attaches and performs a WNOHANG wait(2), it may fail.
113 * write_lock_irq(tasklist_lock)
115 void __ptrace_unlink(struct task_struct *child)
117 const struct cred *old_cred;
118 BUG_ON(!child->ptrace);
120 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
122 child->parent = child->real_parent;
123 list_del_init(&child->ptrace_entry);
124 old_cred = child->ptracer_cred;
125 child->ptracer_cred = NULL;
128 spin_lock(&child->sighand->siglock);
131 * Clear all pending traps and TRAPPING. TRAPPING should be
132 * cleared regardless of JOBCTL_STOP_PENDING. Do it explicitly.
134 task_clear_jobctl_pending(child, JOBCTL_TRAP_MASK);
135 task_clear_jobctl_trapping(child);
138 * Reinstate JOBCTL_STOP_PENDING if group stop is in effect and
141 if (!(child->flags & PF_EXITING) &&
142 (child->signal->flags & SIGNAL_STOP_STOPPED ||
143 child->signal->group_stop_count)) {
144 child->jobctl |= JOBCTL_STOP_PENDING;
147 * This is only possible if this thread was cloned by the
148 * traced task running in the stopped group, set the signal
149 * for the future reports.
150 * FIXME: we should change ptrace_init_task() to handle this
153 if (!(child->jobctl & JOBCTL_STOP_SIGMASK))
154 child->jobctl |= SIGSTOP;
158 * If transition to TASK_STOPPED is pending or in TASK_TRACED, kick
159 * @child in the butt. Note that @resume should be used iff @child
160 * is in TASK_TRACED; otherwise, we might unduly disrupt
161 * TASK_KILLABLE sleeps.
163 if (child->jobctl & JOBCTL_STOP_PENDING || task_is_traced(child))
164 ptrace_signal_wake_up(child, true);
166 spin_unlock(&child->sighand->siglock);
169 /* Ensure that nothing can wake it up, even SIGKILL */
170 static bool ptrace_freeze_traced(struct task_struct *task)
174 /* Lockless, nobody but us can set this flag */
175 if (task->jobctl & JOBCTL_LISTENING)
178 spin_lock_irq(&task->sighand->siglock);
179 if (task_is_traced(task) && !__fatal_signal_pending(task)) {
180 task->state = __TASK_TRACED;
183 spin_unlock_irq(&task->sighand->siglock);
188 static void ptrace_unfreeze_traced(struct task_struct *task)
190 if (task->state != __TASK_TRACED)
193 WARN_ON(!task->ptrace || task->parent != current);
196 * PTRACE_LISTEN can allow ptrace_trap_notify to wake us up remotely.
197 * Recheck state under the lock to close this race.
199 spin_lock_irq(&task->sighand->siglock);
200 if (task->state == __TASK_TRACED) {
201 if (__fatal_signal_pending(task))
202 wake_up_state(task, __TASK_TRACED);
204 task->state = TASK_TRACED;
206 spin_unlock_irq(&task->sighand->siglock);
210 * ptrace_check_attach - check whether ptracee is ready for ptrace operation
211 * @child: ptracee to check for
212 * @ignore_state: don't check whether @child is currently %TASK_TRACED
214 * Check whether @child is being ptraced by %current and ready for further
215 * ptrace operations. If @ignore_state is %false, @child also should be in
216 * %TASK_TRACED state and on return the child is guaranteed to be traced
217 * and not executing. If @ignore_state is %true, @child can be in any
221 * Grabs and releases tasklist_lock and @child->sighand->siglock.
224 * 0 on success, -ESRCH if %child is not ready.
226 static int ptrace_check_attach(struct task_struct *child, bool ignore_state)
231 * We take the read lock around doing both checks to close a
232 * possible race where someone else was tracing our child and
233 * detached between these two checks. After this locked check,
234 * we are sure that this is our traced child and that can only
235 * be changed by us so it's not changing right after this.
237 read_lock(&tasklist_lock);
238 if (child->ptrace && child->parent == current) {
239 WARN_ON(child->state == __TASK_TRACED);
241 * child->sighand can't be NULL, release_task()
242 * does ptrace_unlink() before __exit_signal().
244 if (ignore_state || ptrace_freeze_traced(child))
247 read_unlock(&tasklist_lock);
249 if (!ret && !ignore_state) {
250 if (!wait_task_inactive(child, __TASK_TRACED)) {
252 * This can only happen if may_ptrace_stop() fails and
253 * ptrace_stop() changes ->state back to TASK_RUNNING,
254 * so we should not worry about leaking __TASK_TRACED.
256 WARN_ON(child->state == __TASK_TRACED);
264 static int ptrace_has_cap(struct user_namespace *ns, unsigned int mode)
266 if (mode & PTRACE_MODE_NOAUDIT)
267 return has_ns_capability_noaudit(current, ns, CAP_SYS_PTRACE);
269 return has_ns_capability(current, ns, CAP_SYS_PTRACE);
272 /* Returns 0 on success, -errno on denial. */
273 static int __ptrace_may_access(struct task_struct *task, unsigned int mode)
275 const struct cred *cred = current_cred(), *tcred;
276 struct mm_struct *mm;
280 if (!(mode & PTRACE_MODE_FSCREDS) == !(mode & PTRACE_MODE_REALCREDS)) {
281 WARN(1, "denying ptrace access check without PTRACE_MODE_*CREDS\n");
285 /* May we inspect the given task?
286 * This check is used both for attaching with ptrace
287 * and for allowing access to sensitive information in /proc.
289 * ptrace_attach denies several cases that /proc allows
290 * because setting up the necessary parent/child relationship
291 * or halting the specified task is impossible.
294 /* Don't let security modules deny introspection */
295 if (same_thread_group(task, current))
298 if (mode & PTRACE_MODE_FSCREDS) {
299 caller_uid = cred->fsuid;
300 caller_gid = cred->fsgid;
303 * Using the euid would make more sense here, but something
304 * in userland might rely on the old behavior, and this
305 * shouldn't be a security problem since
306 * PTRACE_MODE_REALCREDS implies that the caller explicitly
307 * used a syscall that requests access to another process
308 * (and not a filesystem syscall to procfs).
310 caller_uid = cred->uid;
311 caller_gid = cred->gid;
313 tcred = __task_cred(task);
314 if (uid_eq(caller_uid, tcred->euid) &&
315 uid_eq(caller_uid, tcred->suid) &&
316 uid_eq(caller_uid, tcred->uid) &&
317 gid_eq(caller_gid, tcred->egid) &&
318 gid_eq(caller_gid, tcred->sgid) &&
319 gid_eq(caller_gid, tcred->gid))
321 if (ptrace_has_cap(tcred->user_ns, mode))
329 ((get_dumpable(mm) != SUID_DUMP_USER) &&
330 !ptrace_has_cap(mm->user_ns, mode)))
333 return security_ptrace_access_check(task, mode);
336 bool ptrace_may_access(struct task_struct *task, unsigned int mode)
340 err = __ptrace_may_access(task, mode);
345 static int ptrace_attach(struct task_struct *task, long request,
349 bool seize = (request == PTRACE_SEIZE);
356 if (flags & ~(unsigned long)PTRACE_O_MASK)
358 flags = PT_PTRACED | PT_SEIZED | (flags << PT_OPT_FLAG_SHIFT);
366 if (unlikely(task->flags & PF_KTHREAD))
368 if (same_thread_group(task, current))
372 * Protect exec's credential calculations against our interference;
373 * SUID, SGID and LSM creds get determined differently
376 retval = -ERESTARTNOINTR;
377 if (mutex_lock_interruptible(&task->signal->cred_guard_mutex))
381 retval = __ptrace_may_access(task, PTRACE_MODE_ATTACH_REALCREDS);
386 write_lock_irq(&tasklist_lock);
388 if (unlikely(task->exit_state))
389 goto unlock_tasklist;
391 goto unlock_tasklist;
395 task->ptrace = flags;
397 ptrace_link(task, current);
399 /* SEIZE doesn't trap tracee on attach */
401 send_sig_info(SIGSTOP, SEND_SIG_PRIV, task);
403 spin_lock(&task->sighand->siglock);
406 * If the task is already STOPPED, set JOBCTL_TRAP_STOP and
407 * TRAPPING, and kick it so that it transits to TRACED. TRAPPING
408 * will be cleared if the child completes the transition or any
409 * event which clears the group stop states happens. We'll wait
410 * for the transition to complete before returning from this
413 * This hides STOPPED -> RUNNING -> TRACED transition from the
414 * attaching thread but a different thread in the same group can
415 * still observe the transient RUNNING state. IOW, if another
416 * thread's WNOHANG wait(2) on the stopped tracee races against
417 * ATTACH, the wait(2) may fail due to the transient RUNNING.
419 * The following task_is_stopped() test is safe as both transitions
420 * in and out of STOPPED are protected by siglock.
422 if (task_is_stopped(task) &&
423 task_set_jobctl_pending(task, JOBCTL_TRAP_STOP | JOBCTL_TRAPPING))
424 signal_wake_up_state(task, __TASK_STOPPED);
426 spin_unlock(&task->sighand->siglock);
430 write_unlock_irq(&tasklist_lock);
432 mutex_unlock(&task->signal->cred_guard_mutex);
436 * We do not bother to change retval or clear JOBCTL_TRAPPING
437 * if wait_on_bit() was interrupted by SIGKILL. The tracer will
438 * not return to user-mode, it will exit and clear this bit in
439 * __ptrace_unlink() if it wasn't already cleared by the tracee;
440 * and until then nobody can ptrace this task.
442 wait_on_bit(&task->jobctl, JOBCTL_TRAPPING_BIT, TASK_KILLABLE);
443 proc_ptrace_connector(task, PTRACE_ATTACH);
450 * ptrace_traceme -- helper for PTRACE_TRACEME
452 * Performs checks and sets PT_PTRACED.
453 * Should be used by all ptrace implementations for PTRACE_TRACEME.
455 static int ptrace_traceme(void)
459 write_lock_irq(&tasklist_lock);
460 /* Are we already being traced? */
461 if (!current->ptrace) {
462 ret = security_ptrace_traceme(current->parent);
464 * Check PF_EXITING to ensure ->real_parent has not passed
465 * exit_ptrace(). Otherwise we don't report the error but
466 * pretend ->real_parent untraces us right after return.
468 if (!ret && !(current->real_parent->flags & PF_EXITING)) {
469 current->ptrace = PT_PTRACED;
470 ptrace_link(current, current->real_parent);
473 write_unlock_irq(&tasklist_lock);
479 * Called with irqs disabled, returns true if childs should reap themselves.
481 static int ignoring_children(struct sighand_struct *sigh)
484 spin_lock(&sigh->siglock);
485 ret = (sigh->action[SIGCHLD-1].sa.sa_handler == SIG_IGN) ||
486 (sigh->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT);
487 spin_unlock(&sigh->siglock);
492 * Called with tasklist_lock held for writing.
493 * Unlink a traced task, and clean it up if it was a traced zombie.
494 * Return true if it needs to be reaped with release_task().
495 * (We can't call release_task() here because we already hold tasklist_lock.)
497 * If it's a zombie, our attachedness prevented normal parent notification
498 * or self-reaping. Do notification now if it would have happened earlier.
499 * If it should reap itself, return true.
501 * If it's our own child, there is no notification to do. But if our normal
502 * children self-reap, then this child was prevented by ptrace and we must
503 * reap it now, in that case we must also wake up sub-threads sleeping in
506 static bool __ptrace_detach(struct task_struct *tracer, struct task_struct *p)
512 if (p->exit_state != EXIT_ZOMBIE)
515 dead = !thread_group_leader(p);
517 if (!dead && thread_group_empty(p)) {
518 if (!same_thread_group(p->real_parent, tracer))
519 dead = do_notify_parent(p, p->exit_signal);
520 else if (ignoring_children(tracer->sighand)) {
521 __wake_up_parent(p, tracer);
525 /* Mark it as in the process of being reaped. */
527 p->exit_state = EXIT_DEAD;
531 static int ptrace_detach(struct task_struct *child, unsigned int data)
533 if (!valid_signal(data))
536 /* Architecture-specific hardware disable .. */
537 ptrace_disable(child);
539 write_lock_irq(&tasklist_lock);
541 * We rely on ptrace_freeze_traced(). It can't be killed and
542 * untraced by another thread, it can't be a zombie.
544 WARN_ON(!child->ptrace || child->exit_state);
546 * tasklist_lock avoids the race with wait_task_stopped(), see
547 * the comment in ptrace_resume().
549 child->exit_code = data;
550 __ptrace_detach(current, child);
551 write_unlock_irq(&tasklist_lock);
553 proc_ptrace_connector(child, PTRACE_DETACH);
559 * Detach all tasks we were using ptrace on. Called with tasklist held
562 void exit_ptrace(struct task_struct *tracer, struct list_head *dead)
564 struct task_struct *p, *n;
566 list_for_each_entry_safe(p, n, &tracer->ptraced, ptrace_entry) {
567 if (unlikely(p->ptrace & PT_EXITKILL))
568 send_sig_info(SIGKILL, SEND_SIG_PRIV, p);
570 if (__ptrace_detach(tracer, p))
571 list_add(&p->ptrace_entry, dead);
575 int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len)
581 int this_len, retval;
583 this_len = (len > sizeof(buf)) ? sizeof(buf) : len;
584 retval = ptrace_access_vm(tsk, src, buf, this_len, FOLL_FORCE);
591 if (copy_to_user(dst, buf, retval))
601 int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len)
607 int this_len, retval;
609 this_len = (len > sizeof(buf)) ? sizeof(buf) : len;
610 if (copy_from_user(buf, src, this_len))
612 retval = ptrace_access_vm(tsk, dst, buf, this_len,
613 FOLL_FORCE | FOLL_WRITE);
627 static int ptrace_setoptions(struct task_struct *child, unsigned long data)
631 if (data & ~(unsigned long)PTRACE_O_MASK)
634 if (unlikely(data & PTRACE_O_SUSPEND_SECCOMP)) {
635 if (!IS_ENABLED(CONFIG_CHECKPOINT_RESTORE) ||
636 !IS_ENABLED(CONFIG_SECCOMP))
639 if (!capable(CAP_SYS_ADMIN))
642 if (seccomp_mode(¤t->seccomp) != SECCOMP_MODE_DISABLED ||
643 current->ptrace & PT_SUSPEND_SECCOMP)
647 /* Avoid intermediate state when all opts are cleared */
648 flags = child->ptrace;
649 flags &= ~(PTRACE_O_MASK << PT_OPT_FLAG_SHIFT);
650 flags |= (data << PT_OPT_FLAG_SHIFT);
651 child->ptrace = flags;
656 static int ptrace_getsiginfo(struct task_struct *child, kernel_siginfo_t *info)
661 if (lock_task_sighand(child, &flags)) {
663 if (likely(child->last_siginfo != NULL)) {
664 copy_siginfo(info, child->last_siginfo);
667 unlock_task_sighand(child, &flags);
672 static int ptrace_setsiginfo(struct task_struct *child, const kernel_siginfo_t *info)
677 if (lock_task_sighand(child, &flags)) {
679 if (likely(child->last_siginfo != NULL)) {
680 copy_siginfo(child->last_siginfo, info);
683 unlock_task_sighand(child, &flags);
688 static int ptrace_peek_siginfo(struct task_struct *child,
692 struct ptrace_peeksiginfo_args arg;
693 struct sigpending *pending;
697 ret = copy_from_user(&arg, (void __user *) addr,
698 sizeof(struct ptrace_peeksiginfo_args));
702 if (arg.flags & ~PTRACE_PEEKSIGINFO_SHARED)
703 return -EINVAL; /* unknown flags */
708 if (arg.flags & PTRACE_PEEKSIGINFO_SHARED)
709 pending = &child->signal->shared_pending;
711 pending = &child->pending;
713 for (i = 0; i < arg.nr; ) {
714 kernel_siginfo_t info;
715 s32 off = arg.off + i;
717 spin_lock_irq(&child->sighand->siglock);
718 list_for_each_entry(q, &pending->list, list) {
720 copy_siginfo(&info, &q->info);
724 spin_unlock_irq(&child->sighand->siglock);
726 if (off >= 0) /* beyond the end of the list */
730 if (unlikely(in_compat_syscall())) {
731 compat_siginfo_t __user *uinfo = compat_ptr(data);
733 if (copy_siginfo_to_user32(uinfo, &info)) {
741 siginfo_t __user *uinfo = (siginfo_t __user *) data;
743 if (copy_siginfo_to_user(uinfo, &info)) {
749 data += sizeof(siginfo_t);
752 if (signal_pending(current))
764 #ifdef PTRACE_SINGLESTEP
765 #define is_singlestep(request) ((request) == PTRACE_SINGLESTEP)
767 #define is_singlestep(request) 0
770 #ifdef PTRACE_SINGLEBLOCK
771 #define is_singleblock(request) ((request) == PTRACE_SINGLEBLOCK)
773 #define is_singleblock(request) 0
777 #define is_sysemu_singlestep(request) ((request) == PTRACE_SYSEMU_SINGLESTEP)
779 #define is_sysemu_singlestep(request) 0
782 static int ptrace_resume(struct task_struct *child, long request,
787 if (!valid_signal(data))
790 if (request == PTRACE_SYSCALL)
791 set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
793 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
795 #ifdef TIF_SYSCALL_EMU
796 if (request == PTRACE_SYSEMU || request == PTRACE_SYSEMU_SINGLESTEP)
797 set_tsk_thread_flag(child, TIF_SYSCALL_EMU);
799 clear_tsk_thread_flag(child, TIF_SYSCALL_EMU);
802 if (is_singleblock(request)) {
803 if (unlikely(!arch_has_block_step()))
805 user_enable_block_step(child);
806 } else if (is_singlestep(request) || is_sysemu_singlestep(request)) {
807 if (unlikely(!arch_has_single_step()))
809 user_enable_single_step(child);
811 user_disable_single_step(child);
815 * Change ->exit_code and ->state under siglock to avoid the race
816 * with wait_task_stopped() in between; a non-zero ->exit_code will
817 * wrongly look like another report from tracee.
819 * Note that we need siglock even if ->exit_code == data and/or this
820 * status was not reported yet, the new status must not be cleared by
821 * wait_task_stopped() after resume.
823 * If data == 0 we do not care if wait_task_stopped() reports the old
824 * status and clears the code too; this can't race with the tracee, it
825 * takes siglock after resume.
827 need_siglock = data && !thread_group_empty(current);
829 spin_lock_irq(&child->sighand->siglock);
830 child->exit_code = data;
831 wake_up_state(child, __TASK_TRACED);
833 spin_unlock_irq(&child->sighand->siglock);
838 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
840 static const struct user_regset *
841 find_regset(const struct user_regset_view *view, unsigned int type)
843 const struct user_regset *regset;
846 for (n = 0; n < view->n; ++n) {
847 regset = view->regsets + n;
848 if (regset->core_note_type == type)
855 static int ptrace_regset(struct task_struct *task, int req, unsigned int type,
858 const struct user_regset_view *view = task_user_regset_view(task);
859 const struct user_regset *regset = find_regset(view, type);
862 if (!regset || (kiov->iov_len % regset->size) != 0)
865 regset_no = regset - view->regsets;
866 kiov->iov_len = min(kiov->iov_len,
867 (__kernel_size_t) (regset->n * regset->size));
869 if (req == PTRACE_GETREGSET)
870 return copy_regset_to_user(task, view, regset_no, 0,
871 kiov->iov_len, kiov->iov_base);
873 return copy_regset_from_user(task, view, regset_no, 0,
874 kiov->iov_len, kiov->iov_base);
878 * This is declared in linux/regset.h and defined in machine-dependent
879 * code. We put the export here, near the primary machine-neutral use,
880 * to ensure no machine forgets it.
882 EXPORT_SYMBOL_GPL(task_user_regset_view);
885 int ptrace_request(struct task_struct *child, long request,
886 unsigned long addr, unsigned long data)
888 bool seized = child->ptrace & PT_SEIZED;
890 kernel_siginfo_t siginfo, *si;
891 void __user *datavp = (void __user *) data;
892 unsigned long __user *datalp = datavp;
896 case PTRACE_PEEKTEXT:
897 case PTRACE_PEEKDATA:
898 return generic_ptrace_peekdata(child, addr, data);
899 case PTRACE_POKETEXT:
900 case PTRACE_POKEDATA:
901 return generic_ptrace_pokedata(child, addr, data);
903 #ifdef PTRACE_OLDSETOPTIONS
904 case PTRACE_OLDSETOPTIONS:
906 case PTRACE_SETOPTIONS:
907 ret = ptrace_setoptions(child, data);
909 case PTRACE_GETEVENTMSG:
910 ret = put_user(child->ptrace_message, datalp);
913 case PTRACE_PEEKSIGINFO:
914 ret = ptrace_peek_siginfo(child, addr, data);
917 case PTRACE_GETSIGINFO:
918 ret = ptrace_getsiginfo(child, &siginfo);
920 ret = copy_siginfo_to_user(datavp, &siginfo);
923 case PTRACE_SETSIGINFO:
924 ret = copy_siginfo_from_user(&siginfo, datavp);
926 ret = ptrace_setsiginfo(child, &siginfo);
929 case PTRACE_GETSIGMASK: {
932 if (addr != sizeof(sigset_t)) {
937 if (test_tsk_restore_sigmask(child))
938 mask = &child->saved_sigmask;
940 mask = &child->blocked;
942 if (copy_to_user(datavp, mask, sizeof(sigset_t)))
950 case PTRACE_SETSIGMASK: {
953 if (addr != sizeof(sigset_t)) {
958 if (copy_from_user(&new_set, datavp, sizeof(sigset_t))) {
963 sigdelsetmask(&new_set, sigmask(SIGKILL)|sigmask(SIGSTOP));
966 * Every thread does recalc_sigpending() after resume, so
967 * retarget_shared_pending() and recalc_sigpending() are not
970 spin_lock_irq(&child->sighand->siglock);
971 child->blocked = new_set;
972 spin_unlock_irq(&child->sighand->siglock);
974 clear_tsk_restore_sigmask(child);
980 case PTRACE_INTERRUPT:
982 * Stop tracee without any side-effect on signal or job
983 * control. At least one trap is guaranteed to happen
984 * after this request. If @child is already trapped, the
985 * current trap is not disturbed and another trap will
986 * happen after the current trap is ended with PTRACE_CONT.
988 * The actual trap might not be PTRACE_EVENT_STOP trap but
989 * the pending condition is cleared regardless.
991 if (unlikely(!seized || !lock_task_sighand(child, &flags)))
995 * INTERRUPT doesn't disturb existing trap sans one
996 * exception. If ptracer issued LISTEN for the current
997 * STOP, this INTERRUPT should clear LISTEN and re-trap
1000 if (likely(task_set_jobctl_pending(child, JOBCTL_TRAP_STOP)))
1001 ptrace_signal_wake_up(child, child->jobctl & JOBCTL_LISTENING);
1003 unlock_task_sighand(child, &flags);
1009 * Listen for events. Tracee must be in STOP. It's not
1010 * resumed per-se but is not considered to be in TRACED by
1011 * wait(2) or ptrace(2). If an async event (e.g. group
1012 * stop state change) happens, tracee will enter STOP trap
1013 * again. Alternatively, ptracer can issue INTERRUPT to
1014 * finish listening and re-trap tracee into STOP.
1016 if (unlikely(!seized || !lock_task_sighand(child, &flags)))
1019 si = child->last_siginfo;
1020 if (likely(si && (si->si_code >> 8) == PTRACE_EVENT_STOP)) {
1021 child->jobctl |= JOBCTL_LISTENING;
1023 * If NOTIFY is set, it means event happened between
1024 * start of this trap and now. Trigger re-trap.
1026 if (child->jobctl & JOBCTL_TRAP_NOTIFY)
1027 ptrace_signal_wake_up(child, true);
1030 unlock_task_sighand(child, &flags);
1033 case PTRACE_DETACH: /* detach a process that was attached. */
1034 ret = ptrace_detach(child, data);
1037 #ifdef CONFIG_BINFMT_ELF_FDPIC
1038 case PTRACE_GETFDPIC: {
1039 struct mm_struct *mm = get_task_mm(child);
1040 unsigned long tmp = 0;
1047 case PTRACE_GETFDPIC_EXEC:
1048 tmp = mm->context.exec_fdpic_loadmap;
1050 case PTRACE_GETFDPIC_INTERP:
1051 tmp = mm->context.interp_fdpic_loadmap;
1058 ret = put_user(tmp, datalp);
1063 #ifdef PTRACE_SINGLESTEP
1064 case PTRACE_SINGLESTEP:
1066 #ifdef PTRACE_SINGLEBLOCK
1067 case PTRACE_SINGLEBLOCK:
1069 #ifdef PTRACE_SYSEMU
1071 case PTRACE_SYSEMU_SINGLESTEP:
1073 case PTRACE_SYSCALL:
1075 return ptrace_resume(child, request, data);
1078 if (child->exit_state) /* already dead */
1080 return ptrace_resume(child, request, SIGKILL);
1082 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
1083 case PTRACE_GETREGSET:
1084 case PTRACE_SETREGSET: {
1086 struct iovec __user *uiov = datavp;
1088 if (!access_ok(uiov, sizeof(*uiov)))
1091 if (__get_user(kiov.iov_base, &uiov->iov_base) ||
1092 __get_user(kiov.iov_len, &uiov->iov_len))
1095 ret = ptrace_regset(child, request, addr, &kiov);
1097 ret = __put_user(kiov.iov_len, &uiov->iov_len);
1102 case PTRACE_SECCOMP_GET_FILTER:
1103 ret = seccomp_get_filter(child, addr, datavp);
1106 case PTRACE_SECCOMP_GET_METADATA:
1107 ret = seccomp_get_metadata(child, addr, datavp);
1117 #ifndef arch_ptrace_attach
1118 #define arch_ptrace_attach(child) do { } while (0)
1121 SYSCALL_DEFINE4(ptrace, long, request, long, pid, unsigned long, addr,
1122 unsigned long, data)
1124 struct task_struct *child;
1127 if (request == PTRACE_TRACEME) {
1128 ret = ptrace_traceme();
1130 arch_ptrace_attach(current);
1134 child = find_get_task_by_vpid(pid);
1140 if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) {
1141 ret = ptrace_attach(child, request, addr, data);
1143 * Some architectures need to do book-keeping after
1147 arch_ptrace_attach(child);
1148 goto out_put_task_struct;
1151 ret = ptrace_check_attach(child, request == PTRACE_KILL ||
1152 request == PTRACE_INTERRUPT);
1154 goto out_put_task_struct;
1156 ret = arch_ptrace(child, request, addr, data);
1157 if (ret || request != PTRACE_DETACH)
1158 ptrace_unfreeze_traced(child);
1160 out_put_task_struct:
1161 put_task_struct(child);
1166 int generic_ptrace_peekdata(struct task_struct *tsk, unsigned long addr,
1172 copied = ptrace_access_vm(tsk, addr, &tmp, sizeof(tmp), FOLL_FORCE);
1173 if (copied != sizeof(tmp))
1175 return put_user(tmp, (unsigned long __user *)data);
1178 int generic_ptrace_pokedata(struct task_struct *tsk, unsigned long addr,
1183 copied = ptrace_access_vm(tsk, addr, &data, sizeof(data),
1184 FOLL_FORCE | FOLL_WRITE);
1185 return (copied == sizeof(data)) ? 0 : -EIO;
1188 #if defined CONFIG_COMPAT
1190 int compat_ptrace_request(struct task_struct *child, compat_long_t request,
1191 compat_ulong_t addr, compat_ulong_t data)
1193 compat_ulong_t __user *datap = compat_ptr(data);
1194 compat_ulong_t word;
1195 kernel_siginfo_t siginfo;
1199 case PTRACE_PEEKTEXT:
1200 case PTRACE_PEEKDATA:
1201 ret = ptrace_access_vm(child, addr, &word, sizeof(word),
1203 if (ret != sizeof(word))
1206 ret = put_user(word, datap);
1209 case PTRACE_POKETEXT:
1210 case PTRACE_POKEDATA:
1211 ret = ptrace_access_vm(child, addr, &data, sizeof(data),
1212 FOLL_FORCE | FOLL_WRITE);
1213 ret = (ret != sizeof(data) ? -EIO : 0);
1216 case PTRACE_GETEVENTMSG:
1217 ret = put_user((compat_ulong_t) child->ptrace_message, datap);
1220 case PTRACE_GETSIGINFO:
1221 ret = ptrace_getsiginfo(child, &siginfo);
1223 ret = copy_siginfo_to_user32(
1224 (struct compat_siginfo __user *) datap,
1228 case PTRACE_SETSIGINFO:
1229 ret = copy_siginfo_from_user32(
1230 &siginfo, (struct compat_siginfo __user *) datap);
1232 ret = ptrace_setsiginfo(child, &siginfo);
1234 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
1235 case PTRACE_GETREGSET:
1236 case PTRACE_SETREGSET:
1239 struct compat_iovec __user *uiov =
1240 (struct compat_iovec __user *) datap;
1244 if (!access_ok(uiov, sizeof(*uiov)))
1247 if (__get_user(ptr, &uiov->iov_base) ||
1248 __get_user(len, &uiov->iov_len))
1251 kiov.iov_base = compat_ptr(ptr);
1254 ret = ptrace_regset(child, request, addr, &kiov);
1256 ret = __put_user(kiov.iov_len, &uiov->iov_len);
1262 ret = ptrace_request(child, request, addr, data);
1268 COMPAT_SYSCALL_DEFINE4(ptrace, compat_long_t, request, compat_long_t, pid,
1269 compat_long_t, addr, compat_long_t, data)
1271 struct task_struct *child;
1274 if (request == PTRACE_TRACEME) {
1275 ret = ptrace_traceme();
1279 child = find_get_task_by_vpid(pid);
1285 if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) {
1286 ret = ptrace_attach(child, request, addr, data);
1288 * Some architectures need to do book-keeping after
1292 arch_ptrace_attach(child);
1293 goto out_put_task_struct;
1296 ret = ptrace_check_attach(child, request == PTRACE_KILL ||
1297 request == PTRACE_INTERRUPT);
1299 ret = compat_arch_ptrace(child, request, addr, data);
1300 if (ret || request != PTRACE_DETACH)
1301 ptrace_unfreeze_traced(child);
1304 out_put_task_struct:
1305 put_task_struct(child);
1309 #endif /* CONFIG_COMPAT */