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/sched/mm.h>
14 #include <linux/sched/coredump.h>
15 #include <linux/sched/task.h>
16 #include <linux/errno.h>
18 #include <linux/highmem.h>
19 #include <linux/pagemap.h>
20 #include <linux/ptrace.h>
21 #include <linux/security.h>
22 #include <linux/signal.h>
23 #include <linux/uio.h>
24 #include <linux/audit.h>
25 #include <linux/pid_namespace.h>
26 #include <linux/syscalls.h>
27 #include <linux/uaccess.h>
28 #include <linux/regset.h>
29 #include <linux/hw_breakpoint.h>
30 #include <linux/cn_proc.h>
31 #include <linux/compat.h>
32 #include <linux/sched/signal.h>
35 * Access another process' address space via ptrace.
36 * Source/target buffer must be kernel space,
37 * Do not walk the page table directly, use get_user_pages
39 int ptrace_access_vm(struct task_struct *tsk, unsigned long addr,
40 void *buf, int len, unsigned int gup_flags)
45 mm = get_task_mm(tsk);
50 (current != tsk->parent) ||
51 ((get_dumpable(mm) != SUID_DUMP_USER) &&
52 !ptracer_capable(tsk, mm->user_ns))) {
57 ret = __access_remote_vm(tsk, mm, addr, buf, len, gup_flags);
64 void __ptrace_link(struct task_struct *child, struct task_struct *new_parent,
65 const struct cred *ptracer_cred)
67 BUG_ON(!list_empty(&child->ptrace_entry));
68 list_add(&child->ptrace_entry, &new_parent->ptraced);
69 child->parent = new_parent;
70 child->ptracer_cred = get_cred(ptracer_cred);
74 * ptrace a task: make the debugger its new parent and
75 * move it to the ptrace list.
77 * Must be called with the tasklist lock write-held.
79 static void ptrace_link(struct task_struct *child, struct task_struct *new_parent)
82 __ptrace_link(child, new_parent, __task_cred(new_parent));
87 * __ptrace_unlink - unlink ptracee and restore its execution state
88 * @child: ptracee to be unlinked
90 * Remove @child from the ptrace list, move it back to the original parent,
91 * and restore the execution state so that it conforms to the group stop
94 * Unlinking can happen via two paths - explicit PTRACE_DETACH or ptracer
95 * exiting. For PTRACE_DETACH, unless the ptracee has been killed between
96 * ptrace_check_attach() and here, it's guaranteed to be in TASK_TRACED.
97 * If the ptracer is exiting, the ptracee can be in any state.
99 * After detach, the ptracee should be in a state which conforms to the
100 * group stop. If the group is stopped or in the process of stopping, the
101 * ptracee should be put into TASK_STOPPED; otherwise, it should be woken
102 * up from TASK_TRACED.
104 * If the ptracee is in TASK_TRACED and needs to be moved to TASK_STOPPED,
105 * it goes through TRACED -> RUNNING -> STOPPED transition which is similar
106 * to but in the opposite direction of what happens while attaching to a
107 * stopped task. However, in this direction, the intermediate RUNNING
108 * state is not hidden even from the current ptracer and if it immediately
109 * re-attaches and performs a WNOHANG wait(2), it may fail.
112 * write_lock_irq(tasklist_lock)
114 void __ptrace_unlink(struct task_struct *child)
116 const struct cred *old_cred;
117 BUG_ON(!child->ptrace);
119 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
121 child->parent = child->real_parent;
122 list_del_init(&child->ptrace_entry);
123 old_cred = child->ptracer_cred;
124 child->ptracer_cred = NULL;
127 spin_lock(&child->sighand->siglock);
130 * Clear all pending traps and TRAPPING. TRAPPING should be
131 * cleared regardless of JOBCTL_STOP_PENDING. Do it explicitly.
133 task_clear_jobctl_pending(child, JOBCTL_TRAP_MASK);
134 task_clear_jobctl_trapping(child);
137 * Reinstate JOBCTL_STOP_PENDING if group stop is in effect and
140 if (!(child->flags & PF_EXITING) &&
141 (child->signal->flags & SIGNAL_STOP_STOPPED ||
142 child->signal->group_stop_count)) {
143 child->jobctl |= JOBCTL_STOP_PENDING;
146 * This is only possible if this thread was cloned by the
147 * traced task running in the stopped group, set the signal
148 * for the future reports.
149 * FIXME: we should change ptrace_init_task() to handle this
152 if (!(child->jobctl & JOBCTL_STOP_SIGMASK))
153 child->jobctl |= SIGSTOP;
157 * If transition to TASK_STOPPED is pending or in TASK_TRACED, kick
158 * @child in the butt. Note that @resume should be used iff @child
159 * is in TASK_TRACED; otherwise, we might unduly disrupt
160 * TASK_KILLABLE sleeps.
162 if (child->jobctl & JOBCTL_STOP_PENDING || task_is_traced(child))
163 ptrace_signal_wake_up(child, true);
165 spin_unlock(&child->sighand->siglock);
168 /* Ensure that nothing can wake it up, even SIGKILL */
169 static bool ptrace_freeze_traced(struct task_struct *task)
173 /* Lockless, nobody but us can set this flag */
174 if (task->jobctl & JOBCTL_LISTENING)
177 spin_lock_irq(&task->sighand->siglock);
178 if (task_is_traced(task) && !__fatal_signal_pending(task)) {
179 task->state = __TASK_TRACED;
182 spin_unlock_irq(&task->sighand->siglock);
187 static void ptrace_unfreeze_traced(struct task_struct *task)
189 if (task->state != __TASK_TRACED)
192 WARN_ON(!task->ptrace || task->parent != current);
195 * PTRACE_LISTEN can allow ptrace_trap_notify to wake us up remotely.
196 * Recheck state under the lock to close this race.
198 spin_lock_irq(&task->sighand->siglock);
199 if (task->state == __TASK_TRACED) {
200 if (__fatal_signal_pending(task))
201 wake_up_state(task, __TASK_TRACED);
203 task->state = TASK_TRACED;
205 spin_unlock_irq(&task->sighand->siglock);
209 * ptrace_check_attach - check whether ptracee is ready for ptrace operation
210 * @child: ptracee to check for
211 * @ignore_state: don't check whether @child is currently %TASK_TRACED
213 * Check whether @child is being ptraced by %current and ready for further
214 * ptrace operations. If @ignore_state is %false, @child also should be in
215 * %TASK_TRACED state and on return the child is guaranteed to be traced
216 * and not executing. If @ignore_state is %true, @child can be in any
220 * Grabs and releases tasklist_lock and @child->sighand->siglock.
223 * 0 on success, -ESRCH if %child is not ready.
225 static int ptrace_check_attach(struct task_struct *child, bool ignore_state)
230 * We take the read lock around doing both checks to close a
231 * possible race where someone else was tracing our child and
232 * detached between these two checks. After this locked check,
233 * we are sure that this is our traced child and that can only
234 * be changed by us so it's not changing right after this.
236 read_lock(&tasklist_lock);
237 if (child->ptrace && child->parent == current) {
238 WARN_ON(child->state == __TASK_TRACED);
240 * child->sighand can't be NULL, release_task()
241 * does ptrace_unlink() before __exit_signal().
243 if (ignore_state || ptrace_freeze_traced(child))
246 read_unlock(&tasklist_lock);
248 if (!ret && !ignore_state) {
249 if (!wait_task_inactive(child, __TASK_TRACED)) {
251 * This can only happen if may_ptrace_stop() fails and
252 * ptrace_stop() changes ->state back to TASK_RUNNING,
253 * so we should not worry about leaking __TASK_TRACED.
255 WARN_ON(child->state == __TASK_TRACED);
263 static int ptrace_has_cap(struct user_namespace *ns, unsigned int mode)
265 if (mode & PTRACE_MODE_NOAUDIT)
266 return has_ns_capability_noaudit(current, ns, CAP_SYS_PTRACE);
268 return has_ns_capability(current, ns, CAP_SYS_PTRACE);
271 /* Returns 0 on success, -errno on denial. */
272 static int __ptrace_may_access(struct task_struct *task, unsigned int mode)
274 const struct cred *cred = current_cred(), *tcred;
275 struct mm_struct *mm;
279 if (!(mode & PTRACE_MODE_FSCREDS) == !(mode & PTRACE_MODE_REALCREDS)) {
280 WARN(1, "denying ptrace access check without PTRACE_MODE_*CREDS\n");
284 /* May we inspect the given task?
285 * This check is used both for attaching with ptrace
286 * and for allowing access to sensitive information in /proc.
288 * ptrace_attach denies several cases that /proc allows
289 * because setting up the necessary parent/child relationship
290 * or halting the specified task is impossible.
293 /* Don't let security modules deny introspection */
294 if (same_thread_group(task, current))
297 if (mode & PTRACE_MODE_FSCREDS) {
298 caller_uid = cred->fsuid;
299 caller_gid = cred->fsgid;
302 * Using the euid would make more sense here, but something
303 * in userland might rely on the old behavior, and this
304 * shouldn't be a security problem since
305 * PTRACE_MODE_REALCREDS implies that the caller explicitly
306 * used a syscall that requests access to another process
307 * (and not a filesystem syscall to procfs).
309 caller_uid = cred->uid;
310 caller_gid = cred->gid;
312 tcred = __task_cred(task);
313 if (uid_eq(caller_uid, tcred->euid) &&
314 uid_eq(caller_uid, tcred->suid) &&
315 uid_eq(caller_uid, tcred->uid) &&
316 gid_eq(caller_gid, tcred->egid) &&
317 gid_eq(caller_gid, tcred->sgid) &&
318 gid_eq(caller_gid, tcred->gid))
320 if (ptrace_has_cap(tcred->user_ns, mode))
327 * If a task drops privileges and becomes nondumpable (through a syscall
328 * like setresuid()) while we are trying to access it, we must ensure
329 * that the dumpability is read after the credentials; otherwise,
330 * we may be able to attach to a task that we shouldn't be able to
331 * attach to (as if the task had dropped privileges without becoming
333 * Pairs with a write barrier in commit_creds().
338 ((get_dumpable(mm) != SUID_DUMP_USER) &&
339 !ptrace_has_cap(mm->user_ns, mode)))
342 return security_ptrace_access_check(task, mode);
345 bool ptrace_may_access(struct task_struct *task, unsigned int mode)
349 err = __ptrace_may_access(task, mode);
354 static int ptrace_attach(struct task_struct *task, long request,
358 bool seize = (request == PTRACE_SEIZE);
365 if (flags & ~(unsigned long)PTRACE_O_MASK)
367 flags = PT_PTRACED | PT_SEIZED | (flags << PT_OPT_FLAG_SHIFT);
375 if (unlikely(task->flags & PF_KTHREAD))
377 if (same_thread_group(task, current))
381 * Protect exec's credential calculations against our interference;
382 * SUID, SGID and LSM creds get determined differently
385 retval = -ERESTARTNOINTR;
386 if (mutex_lock_interruptible(&task->signal->cred_guard_mutex))
390 retval = __ptrace_may_access(task, PTRACE_MODE_ATTACH_REALCREDS);
395 write_lock_irq(&tasklist_lock);
397 if (unlikely(task->exit_state))
398 goto unlock_tasklist;
400 goto unlock_tasklist;
404 task->ptrace = flags;
406 ptrace_link(task, current);
408 /* SEIZE doesn't trap tracee on attach */
410 send_sig_info(SIGSTOP, SEND_SIG_FORCED, task);
412 spin_lock(&task->sighand->siglock);
415 * If the task is already STOPPED, set JOBCTL_TRAP_STOP and
416 * TRAPPING, and kick it so that it transits to TRACED. TRAPPING
417 * will be cleared if the child completes the transition or any
418 * event which clears the group stop states happens. We'll wait
419 * for the transition to complete before returning from this
422 * This hides STOPPED -> RUNNING -> TRACED transition from the
423 * attaching thread but a different thread in the same group can
424 * still observe the transient RUNNING state. IOW, if another
425 * thread's WNOHANG wait(2) on the stopped tracee races against
426 * ATTACH, the wait(2) may fail due to the transient RUNNING.
428 * The following task_is_stopped() test is safe as both transitions
429 * in and out of STOPPED are protected by siglock.
431 if (task_is_stopped(task) &&
432 task_set_jobctl_pending(task, JOBCTL_TRAP_STOP | JOBCTL_TRAPPING))
433 signal_wake_up_state(task, __TASK_STOPPED);
435 spin_unlock(&task->sighand->siglock);
439 write_unlock_irq(&tasklist_lock);
441 mutex_unlock(&task->signal->cred_guard_mutex);
445 * We do not bother to change retval or clear JOBCTL_TRAPPING
446 * if wait_on_bit() was interrupted by SIGKILL. The tracer will
447 * not return to user-mode, it will exit and clear this bit in
448 * __ptrace_unlink() if it wasn't already cleared by the tracee;
449 * and until then nobody can ptrace this task.
451 wait_on_bit(&task->jobctl, JOBCTL_TRAPPING_BIT, TASK_KILLABLE);
452 proc_ptrace_connector(task, PTRACE_ATTACH);
459 * ptrace_traceme -- helper for PTRACE_TRACEME
461 * Performs checks and sets PT_PTRACED.
462 * Should be used by all ptrace implementations for PTRACE_TRACEME.
464 static int ptrace_traceme(void)
468 write_lock_irq(&tasklist_lock);
469 /* Are we already being traced? */
470 if (!current->ptrace) {
471 ret = security_ptrace_traceme(current->parent);
473 * Check PF_EXITING to ensure ->real_parent has not passed
474 * exit_ptrace(). Otherwise we don't report the error but
475 * pretend ->real_parent untraces us right after return.
477 if (!ret && !(current->real_parent->flags & PF_EXITING)) {
478 current->ptrace = PT_PTRACED;
479 ptrace_link(current, current->real_parent);
482 write_unlock_irq(&tasklist_lock);
488 * Called with irqs disabled, returns true if childs should reap themselves.
490 static int ignoring_children(struct sighand_struct *sigh)
493 spin_lock(&sigh->siglock);
494 ret = (sigh->action[SIGCHLD-1].sa.sa_handler == SIG_IGN) ||
495 (sigh->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT);
496 spin_unlock(&sigh->siglock);
501 * Called with tasklist_lock held for writing.
502 * Unlink a traced task, and clean it up if it was a traced zombie.
503 * Return true if it needs to be reaped with release_task().
504 * (We can't call release_task() here because we already hold tasklist_lock.)
506 * If it's a zombie, our attachedness prevented normal parent notification
507 * or self-reaping. Do notification now if it would have happened earlier.
508 * If it should reap itself, return true.
510 * If it's our own child, there is no notification to do. But if our normal
511 * children self-reap, then this child was prevented by ptrace and we must
512 * reap it now, in that case we must also wake up sub-threads sleeping in
515 static bool __ptrace_detach(struct task_struct *tracer, struct task_struct *p)
521 if (p->exit_state != EXIT_ZOMBIE)
524 dead = !thread_group_leader(p);
526 if (!dead && thread_group_empty(p)) {
527 if (!same_thread_group(p->real_parent, tracer))
528 dead = do_notify_parent(p, p->exit_signal);
529 else if (ignoring_children(tracer->sighand)) {
530 __wake_up_parent(p, tracer);
534 /* Mark it as in the process of being reaped. */
536 p->exit_state = EXIT_DEAD;
540 static int ptrace_detach(struct task_struct *child, unsigned int data)
542 if (!valid_signal(data))
545 /* Architecture-specific hardware disable .. */
546 ptrace_disable(child);
548 write_lock_irq(&tasklist_lock);
550 * We rely on ptrace_freeze_traced(). It can't be killed and
551 * untraced by another thread, it can't be a zombie.
553 WARN_ON(!child->ptrace || child->exit_state);
555 * tasklist_lock avoids the race with wait_task_stopped(), see
556 * the comment in ptrace_resume().
558 child->exit_code = data;
559 __ptrace_detach(current, child);
560 write_unlock_irq(&tasklist_lock);
562 proc_ptrace_connector(child, PTRACE_DETACH);
568 * Detach all tasks we were using ptrace on. Called with tasklist held
571 void exit_ptrace(struct task_struct *tracer, struct list_head *dead)
573 struct task_struct *p, *n;
575 list_for_each_entry_safe(p, n, &tracer->ptraced, ptrace_entry) {
576 if (unlikely(p->ptrace & PT_EXITKILL))
577 send_sig_info(SIGKILL, SEND_SIG_FORCED, p);
579 if (__ptrace_detach(tracer, p))
580 list_add(&p->ptrace_entry, dead);
584 int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len)
590 int this_len, retval;
592 this_len = (len > sizeof(buf)) ? sizeof(buf) : len;
593 retval = ptrace_access_vm(tsk, src, buf, this_len, FOLL_FORCE);
600 if (copy_to_user(dst, buf, retval))
610 int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len)
616 int this_len, retval;
618 this_len = (len > sizeof(buf)) ? sizeof(buf) : len;
619 if (copy_from_user(buf, src, this_len))
621 retval = ptrace_access_vm(tsk, dst, buf, this_len,
622 FOLL_FORCE | FOLL_WRITE);
636 static int ptrace_setoptions(struct task_struct *child, unsigned long data)
640 if (data & ~(unsigned long)PTRACE_O_MASK)
643 if (unlikely(data & PTRACE_O_SUSPEND_SECCOMP)) {
644 if (!IS_ENABLED(CONFIG_CHECKPOINT_RESTORE) ||
645 !IS_ENABLED(CONFIG_SECCOMP))
648 if (!capable(CAP_SYS_ADMIN))
651 if (seccomp_mode(¤t->seccomp) != SECCOMP_MODE_DISABLED ||
652 current->ptrace & PT_SUSPEND_SECCOMP)
656 /* Avoid intermediate state when all opts are cleared */
657 flags = child->ptrace;
658 flags &= ~(PTRACE_O_MASK << PT_OPT_FLAG_SHIFT);
659 flags |= (data << PT_OPT_FLAG_SHIFT);
660 child->ptrace = flags;
665 static int ptrace_getsiginfo(struct task_struct *child, siginfo_t *info)
670 if (lock_task_sighand(child, &flags)) {
672 if (likely(child->last_siginfo != NULL)) {
673 copy_siginfo(info, child->last_siginfo);
676 unlock_task_sighand(child, &flags);
681 static int ptrace_setsiginfo(struct task_struct *child, const siginfo_t *info)
686 if (lock_task_sighand(child, &flags)) {
688 if (likely(child->last_siginfo != NULL)) {
689 copy_siginfo(child->last_siginfo, info);
692 unlock_task_sighand(child, &flags);
697 static int ptrace_peek_siginfo(struct task_struct *child,
701 struct ptrace_peeksiginfo_args arg;
702 struct sigpending *pending;
706 ret = copy_from_user(&arg, (void __user *) addr,
707 sizeof(struct ptrace_peeksiginfo_args));
711 if (arg.flags & ~PTRACE_PEEKSIGINFO_SHARED)
712 return -EINVAL; /* unknown flags */
717 /* Ensure arg.off fits in an unsigned long */
718 if (arg.off > ULONG_MAX)
721 if (arg.flags & PTRACE_PEEKSIGINFO_SHARED)
722 pending = &child->signal->shared_pending;
724 pending = &child->pending;
726 for (i = 0; i < arg.nr; ) {
728 unsigned long off = arg.off + i;
731 spin_lock_irq(&child->sighand->siglock);
732 list_for_each_entry(q, &pending->list, list) {
735 copy_siginfo(&info, &q->info);
739 spin_unlock_irq(&child->sighand->siglock);
741 if (!found) /* beyond the end of the list */
745 if (unlikely(in_compat_syscall())) {
746 compat_siginfo_t __user *uinfo = compat_ptr(data);
748 if (copy_siginfo_to_user32(uinfo, &info)) {
756 siginfo_t __user *uinfo = (siginfo_t __user *) data;
758 if (copy_siginfo_to_user(uinfo, &info)) {
764 data += sizeof(siginfo_t);
767 if (signal_pending(current))
779 #ifdef PTRACE_SINGLESTEP
780 #define is_singlestep(request) ((request) == PTRACE_SINGLESTEP)
782 #define is_singlestep(request) 0
785 #ifdef PTRACE_SINGLEBLOCK
786 #define is_singleblock(request) ((request) == PTRACE_SINGLEBLOCK)
788 #define is_singleblock(request) 0
792 #define is_sysemu_singlestep(request) ((request) == PTRACE_SYSEMU_SINGLESTEP)
794 #define is_sysemu_singlestep(request) 0
797 static int ptrace_resume(struct task_struct *child, long request,
802 if (!valid_signal(data))
805 if (request == PTRACE_SYSCALL)
806 set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
808 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
810 #ifdef TIF_SYSCALL_EMU
811 if (request == PTRACE_SYSEMU || request == PTRACE_SYSEMU_SINGLESTEP)
812 set_tsk_thread_flag(child, TIF_SYSCALL_EMU);
814 clear_tsk_thread_flag(child, TIF_SYSCALL_EMU);
817 if (is_singleblock(request)) {
818 if (unlikely(!arch_has_block_step()))
820 user_enable_block_step(child);
821 } else if (is_singlestep(request) || is_sysemu_singlestep(request)) {
822 if (unlikely(!arch_has_single_step()))
824 user_enable_single_step(child);
826 user_disable_single_step(child);
830 * Change ->exit_code and ->state under siglock to avoid the race
831 * with wait_task_stopped() in between; a non-zero ->exit_code will
832 * wrongly look like another report from tracee.
834 * Note that we need siglock even if ->exit_code == data and/or this
835 * status was not reported yet, the new status must not be cleared by
836 * wait_task_stopped() after resume.
838 * If data == 0 we do not care if wait_task_stopped() reports the old
839 * status and clears the code too; this can't race with the tracee, it
840 * takes siglock after resume.
842 need_siglock = data && !thread_group_empty(current);
844 spin_lock_irq(&child->sighand->siglock);
845 child->exit_code = data;
846 wake_up_state(child, __TASK_TRACED);
848 spin_unlock_irq(&child->sighand->siglock);
853 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
855 static const struct user_regset *
856 find_regset(const struct user_regset_view *view, unsigned int type)
858 const struct user_regset *regset;
861 for (n = 0; n < view->n; ++n) {
862 regset = view->regsets + n;
863 if (regset->core_note_type == type)
870 static int ptrace_regset(struct task_struct *task, int req, unsigned int type,
873 const struct user_regset_view *view = task_user_regset_view(task);
874 const struct user_regset *regset = find_regset(view, type);
877 if (!regset || (kiov->iov_len % regset->size) != 0)
880 regset_no = regset - view->regsets;
881 kiov->iov_len = min(kiov->iov_len,
882 (__kernel_size_t) (regset->n * regset->size));
884 if (req == PTRACE_GETREGSET)
885 return copy_regset_to_user(task, view, regset_no, 0,
886 kiov->iov_len, kiov->iov_base);
888 return copy_regset_from_user(task, view, regset_no, 0,
889 kiov->iov_len, kiov->iov_base);
893 * This is declared in linux/regset.h and defined in machine-dependent
894 * code. We put the export here, near the primary machine-neutral use,
895 * to ensure no machine forgets it.
897 EXPORT_SYMBOL_GPL(task_user_regset_view);
900 int ptrace_request(struct task_struct *child, long request,
901 unsigned long addr, unsigned long data)
903 bool seized = child->ptrace & PT_SEIZED;
905 siginfo_t siginfo, *si;
906 void __user *datavp = (void __user *) data;
907 unsigned long __user *datalp = datavp;
911 case PTRACE_PEEKTEXT:
912 case PTRACE_PEEKDATA:
913 return generic_ptrace_peekdata(child, addr, data);
914 case PTRACE_POKETEXT:
915 case PTRACE_POKEDATA:
916 return generic_ptrace_pokedata(child, addr, data);
918 #ifdef PTRACE_OLDSETOPTIONS
919 case PTRACE_OLDSETOPTIONS:
921 case PTRACE_SETOPTIONS:
922 ret = ptrace_setoptions(child, data);
924 case PTRACE_GETEVENTMSG:
925 ret = put_user(child->ptrace_message, datalp);
928 case PTRACE_PEEKSIGINFO:
929 ret = ptrace_peek_siginfo(child, addr, data);
932 case PTRACE_GETSIGINFO:
933 ret = ptrace_getsiginfo(child, &siginfo);
935 ret = copy_siginfo_to_user(datavp, &siginfo);
938 case PTRACE_SETSIGINFO:
939 if (copy_from_user(&siginfo, datavp, sizeof siginfo))
942 ret = ptrace_setsiginfo(child, &siginfo);
945 case PTRACE_GETSIGMASK: {
948 if (addr != sizeof(sigset_t)) {
953 if (test_tsk_restore_sigmask(child))
954 mask = &child->saved_sigmask;
956 mask = &child->blocked;
958 if (copy_to_user(datavp, mask, sizeof(sigset_t)))
966 case PTRACE_SETSIGMASK: {
969 if (addr != sizeof(sigset_t)) {
974 if (copy_from_user(&new_set, datavp, sizeof(sigset_t))) {
979 sigdelsetmask(&new_set, sigmask(SIGKILL)|sigmask(SIGSTOP));
982 * Every thread does recalc_sigpending() after resume, so
983 * retarget_shared_pending() and recalc_sigpending() are not
986 spin_lock_irq(&child->sighand->siglock);
987 child->blocked = new_set;
988 spin_unlock_irq(&child->sighand->siglock);
990 clear_tsk_restore_sigmask(child);
996 case PTRACE_INTERRUPT:
998 * Stop tracee without any side-effect on signal or job
999 * control. At least one trap is guaranteed to happen
1000 * after this request. If @child is already trapped, the
1001 * current trap is not disturbed and another trap will
1002 * happen after the current trap is ended with PTRACE_CONT.
1004 * The actual trap might not be PTRACE_EVENT_STOP trap but
1005 * the pending condition is cleared regardless.
1007 if (unlikely(!seized || !lock_task_sighand(child, &flags)))
1011 * INTERRUPT doesn't disturb existing trap sans one
1012 * exception. If ptracer issued LISTEN for the current
1013 * STOP, this INTERRUPT should clear LISTEN and re-trap
1016 if (likely(task_set_jobctl_pending(child, JOBCTL_TRAP_STOP)))
1017 ptrace_signal_wake_up(child, child->jobctl & JOBCTL_LISTENING);
1019 unlock_task_sighand(child, &flags);
1025 * Listen for events. Tracee must be in STOP. It's not
1026 * resumed per-se but is not considered to be in TRACED by
1027 * wait(2) or ptrace(2). If an async event (e.g. group
1028 * stop state change) happens, tracee will enter STOP trap
1029 * again. Alternatively, ptracer can issue INTERRUPT to
1030 * finish listening and re-trap tracee into STOP.
1032 if (unlikely(!seized || !lock_task_sighand(child, &flags)))
1035 si = child->last_siginfo;
1036 if (likely(si && (si->si_code >> 8) == PTRACE_EVENT_STOP)) {
1037 child->jobctl |= JOBCTL_LISTENING;
1039 * If NOTIFY is set, it means event happened between
1040 * start of this trap and now. Trigger re-trap.
1042 if (child->jobctl & JOBCTL_TRAP_NOTIFY)
1043 ptrace_signal_wake_up(child, true);
1046 unlock_task_sighand(child, &flags);
1049 case PTRACE_DETACH: /* detach a process that was attached. */
1050 ret = ptrace_detach(child, data);
1053 #ifdef CONFIG_BINFMT_ELF_FDPIC
1054 case PTRACE_GETFDPIC: {
1055 struct mm_struct *mm = get_task_mm(child);
1056 unsigned long tmp = 0;
1063 case PTRACE_GETFDPIC_EXEC:
1064 tmp = mm->context.exec_fdpic_loadmap;
1066 case PTRACE_GETFDPIC_INTERP:
1067 tmp = mm->context.interp_fdpic_loadmap;
1074 ret = put_user(tmp, datalp);
1079 #ifdef PTRACE_SINGLESTEP
1080 case PTRACE_SINGLESTEP:
1082 #ifdef PTRACE_SINGLEBLOCK
1083 case PTRACE_SINGLEBLOCK:
1085 #ifdef PTRACE_SYSEMU
1087 case PTRACE_SYSEMU_SINGLESTEP:
1089 case PTRACE_SYSCALL:
1091 return ptrace_resume(child, request, data);
1094 if (child->exit_state) /* already dead */
1096 return ptrace_resume(child, request, SIGKILL);
1098 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
1099 case PTRACE_GETREGSET:
1100 case PTRACE_SETREGSET: {
1102 struct iovec __user *uiov = datavp;
1104 if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov)))
1107 if (__get_user(kiov.iov_base, &uiov->iov_base) ||
1108 __get_user(kiov.iov_len, &uiov->iov_len))
1111 ret = ptrace_regset(child, request, addr, &kiov);
1113 ret = __put_user(kiov.iov_len, &uiov->iov_len);
1118 case PTRACE_SECCOMP_GET_FILTER:
1119 ret = seccomp_get_filter(child, addr, datavp);
1122 case PTRACE_SECCOMP_GET_METADATA:
1123 ret = seccomp_get_metadata(child, addr, datavp);
1133 #ifndef arch_ptrace_attach
1134 #define arch_ptrace_attach(child) do { } while (0)
1137 SYSCALL_DEFINE4(ptrace, long, request, long, pid, unsigned long, addr,
1138 unsigned long, data)
1140 struct task_struct *child;
1143 if (request == PTRACE_TRACEME) {
1144 ret = ptrace_traceme();
1146 arch_ptrace_attach(current);
1150 child = find_get_task_by_vpid(pid);
1156 if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) {
1157 ret = ptrace_attach(child, request, addr, data);
1159 * Some architectures need to do book-keeping after
1163 arch_ptrace_attach(child);
1164 goto out_put_task_struct;
1167 ret = ptrace_check_attach(child, request == PTRACE_KILL ||
1168 request == PTRACE_INTERRUPT);
1170 goto out_put_task_struct;
1172 ret = arch_ptrace(child, request, addr, data);
1173 if (ret || request != PTRACE_DETACH)
1174 ptrace_unfreeze_traced(child);
1176 out_put_task_struct:
1177 put_task_struct(child);
1182 int generic_ptrace_peekdata(struct task_struct *tsk, unsigned long addr,
1188 copied = ptrace_access_vm(tsk, addr, &tmp, sizeof(tmp), FOLL_FORCE);
1189 if (copied != sizeof(tmp))
1191 return put_user(tmp, (unsigned long __user *)data);
1194 int generic_ptrace_pokedata(struct task_struct *tsk, unsigned long addr,
1199 copied = ptrace_access_vm(tsk, addr, &data, sizeof(data),
1200 FOLL_FORCE | FOLL_WRITE);
1201 return (copied == sizeof(data)) ? 0 : -EIO;
1204 #if defined CONFIG_COMPAT
1206 int compat_ptrace_request(struct task_struct *child, compat_long_t request,
1207 compat_ulong_t addr, compat_ulong_t data)
1209 compat_ulong_t __user *datap = compat_ptr(data);
1210 compat_ulong_t word;
1215 case PTRACE_PEEKTEXT:
1216 case PTRACE_PEEKDATA:
1217 ret = ptrace_access_vm(child, addr, &word, sizeof(word),
1219 if (ret != sizeof(word))
1222 ret = put_user(word, datap);
1225 case PTRACE_POKETEXT:
1226 case PTRACE_POKEDATA:
1227 ret = ptrace_access_vm(child, addr, &data, sizeof(data),
1228 FOLL_FORCE | FOLL_WRITE);
1229 ret = (ret != sizeof(data) ? -EIO : 0);
1232 case PTRACE_GETEVENTMSG:
1233 ret = put_user((compat_ulong_t) child->ptrace_message, datap);
1236 case PTRACE_GETSIGINFO:
1237 ret = ptrace_getsiginfo(child, &siginfo);
1239 ret = copy_siginfo_to_user32(
1240 (struct compat_siginfo __user *) datap,
1244 case PTRACE_SETSIGINFO:
1245 if (copy_siginfo_from_user32(
1246 &siginfo, (struct compat_siginfo __user *) datap))
1249 ret = ptrace_setsiginfo(child, &siginfo);
1251 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
1252 case PTRACE_GETREGSET:
1253 case PTRACE_SETREGSET:
1256 struct compat_iovec __user *uiov =
1257 (struct compat_iovec __user *) datap;
1261 if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov)))
1264 if (__get_user(ptr, &uiov->iov_base) ||
1265 __get_user(len, &uiov->iov_len))
1268 kiov.iov_base = compat_ptr(ptr);
1271 ret = ptrace_regset(child, request, addr, &kiov);
1273 ret = __put_user(kiov.iov_len, &uiov->iov_len);
1279 ret = ptrace_request(child, request, addr, data);
1285 COMPAT_SYSCALL_DEFINE4(ptrace, compat_long_t, request, compat_long_t, pid,
1286 compat_long_t, addr, compat_long_t, data)
1288 struct task_struct *child;
1291 if (request == PTRACE_TRACEME) {
1292 ret = ptrace_traceme();
1296 child = find_get_task_by_vpid(pid);
1302 if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) {
1303 ret = ptrace_attach(child, request, addr, data);
1305 * Some architectures need to do book-keeping after
1309 arch_ptrace_attach(child);
1310 goto out_put_task_struct;
1313 ret = ptrace_check_attach(child, request == PTRACE_KILL ||
1314 request == PTRACE_INTERRUPT);
1316 ret = compat_arch_ptrace(child, request, addr, data);
1317 if (ret || request != PTRACE_DETACH)
1318 ptrace_unfreeze_traced(child);
1321 out_put_task_struct:
1322 put_task_struct(child);
1326 #endif /* CONFIG_COMPAT */