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)
82 __ptrace_link(child, new_parent, current_cred());
86 * __ptrace_unlink - unlink ptracee and restore its execution state
87 * @child: ptracee to be unlinked
89 * Remove @child from the ptrace list, move it back to the original parent,
90 * and restore the execution state so that it conforms to the group stop
93 * Unlinking can happen via two paths - explicit PTRACE_DETACH or ptracer
94 * exiting. For PTRACE_DETACH, unless the ptracee has been killed between
95 * ptrace_check_attach() and here, it's guaranteed to be in TASK_TRACED.
96 * If the ptracer is exiting, the ptracee can be in any state.
98 * After detach, the ptracee should be in a state which conforms to the
99 * group stop. If the group is stopped or in the process of stopping, the
100 * ptracee should be put into TASK_STOPPED; otherwise, it should be woken
101 * up from TASK_TRACED.
103 * If the ptracee is in TASK_TRACED and needs to be moved to TASK_STOPPED,
104 * it goes through TRACED -> RUNNING -> STOPPED transition which is similar
105 * to but in the opposite direction of what happens while attaching to a
106 * stopped task. However, in this direction, the intermediate RUNNING
107 * state is not hidden even from the current ptracer and if it immediately
108 * re-attaches and performs a WNOHANG wait(2), it may fail.
111 * write_lock_irq(tasklist_lock)
113 void __ptrace_unlink(struct task_struct *child)
115 const struct cred *old_cred;
116 BUG_ON(!child->ptrace);
118 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
119 #ifdef TIF_SYSCALL_EMU
120 clear_tsk_thread_flag(child, TIF_SYSCALL_EMU);
123 child->parent = child->real_parent;
124 list_del_init(&child->ptrace_entry);
125 old_cred = child->ptracer_cred;
126 child->ptracer_cred = NULL;
129 spin_lock(&child->sighand->siglock);
132 * Clear all pending traps and TRAPPING. TRAPPING should be
133 * cleared regardless of JOBCTL_STOP_PENDING. Do it explicitly.
135 task_clear_jobctl_pending(child, JOBCTL_TRAP_MASK);
136 task_clear_jobctl_trapping(child);
139 * Reinstate JOBCTL_STOP_PENDING if group stop is in effect and
142 if (!(child->flags & PF_EXITING) &&
143 (child->signal->flags & SIGNAL_STOP_STOPPED ||
144 child->signal->group_stop_count)) {
145 child->jobctl |= JOBCTL_STOP_PENDING;
148 * This is only possible if this thread was cloned by the
149 * traced task running in the stopped group, set the signal
150 * for the future reports.
151 * FIXME: we should change ptrace_init_task() to handle this
154 if (!(child->jobctl & JOBCTL_STOP_SIGMASK))
155 child->jobctl |= SIGSTOP;
159 * If transition to TASK_STOPPED is pending or in TASK_TRACED, kick
160 * @child in the butt. Note that @resume should be used iff @child
161 * is in TASK_TRACED; otherwise, we might unduly disrupt
162 * TASK_KILLABLE sleeps.
164 if (child->jobctl & JOBCTL_STOP_PENDING || task_is_traced(child))
165 ptrace_signal_wake_up(child, true);
167 spin_unlock(&child->sighand->siglock);
170 /* Ensure that nothing can wake it up, even SIGKILL */
171 static bool ptrace_freeze_traced(struct task_struct *task)
175 /* Lockless, nobody but us can set this flag */
176 if (task->jobctl & JOBCTL_LISTENING)
179 spin_lock_irq(&task->sighand->siglock);
180 if (task_is_traced(task) && !__fatal_signal_pending(task)) {
181 task->state = __TASK_TRACED;
184 spin_unlock_irq(&task->sighand->siglock);
189 static void ptrace_unfreeze_traced(struct task_struct *task)
191 if (task->state != __TASK_TRACED)
194 WARN_ON(!task->ptrace || task->parent != current);
197 * PTRACE_LISTEN can allow ptrace_trap_notify to wake us up remotely.
198 * Recheck state under the lock to close this race.
200 spin_lock_irq(&task->sighand->siglock);
201 if (task->state == __TASK_TRACED) {
202 if (__fatal_signal_pending(task))
203 wake_up_state(task, __TASK_TRACED);
205 task->state = TASK_TRACED;
207 spin_unlock_irq(&task->sighand->siglock);
211 * ptrace_check_attach - check whether ptracee is ready for ptrace operation
212 * @child: ptracee to check for
213 * @ignore_state: don't check whether @child is currently %TASK_TRACED
215 * Check whether @child is being ptraced by %current and ready for further
216 * ptrace operations. If @ignore_state is %false, @child also should be in
217 * %TASK_TRACED state and on return the child is guaranteed to be traced
218 * and not executing. If @ignore_state is %true, @child can be in any
222 * Grabs and releases tasklist_lock and @child->sighand->siglock.
225 * 0 on success, -ESRCH if %child is not ready.
227 static int ptrace_check_attach(struct task_struct *child, bool ignore_state)
232 * We take the read lock around doing both checks to close a
233 * possible race where someone else was tracing our child and
234 * detached between these two checks. After this locked check,
235 * we are sure that this is our traced child and that can only
236 * be changed by us so it's not changing right after this.
238 read_lock(&tasklist_lock);
239 if (child->ptrace && child->parent == current) {
240 WARN_ON(child->state == __TASK_TRACED);
242 * child->sighand can't be NULL, release_task()
243 * does ptrace_unlink() before __exit_signal().
245 if (ignore_state || ptrace_freeze_traced(child))
248 read_unlock(&tasklist_lock);
250 if (!ret && !ignore_state) {
251 if (!wait_task_inactive(child, __TASK_TRACED)) {
253 * This can only happen if may_ptrace_stop() fails and
254 * ptrace_stop() changes ->state back to TASK_RUNNING,
255 * so we should not worry about leaking __TASK_TRACED.
257 WARN_ON(child->state == __TASK_TRACED);
265 static int ptrace_has_cap(struct user_namespace *ns, unsigned int mode)
267 if (mode & PTRACE_MODE_NOAUDIT)
268 return has_ns_capability_noaudit(current, ns, CAP_SYS_PTRACE);
270 return has_ns_capability(current, ns, CAP_SYS_PTRACE);
273 /* Returns 0 on success, -errno on denial. */
274 static int __ptrace_may_access(struct task_struct *task, unsigned int mode)
276 const struct cred *cred = current_cred(), *tcred;
277 struct mm_struct *mm;
281 if (!(mode & PTRACE_MODE_FSCREDS) == !(mode & PTRACE_MODE_REALCREDS)) {
282 WARN(1, "denying ptrace access check without PTRACE_MODE_*CREDS\n");
286 /* May we inspect the given task?
287 * This check is used both for attaching with ptrace
288 * and for allowing access to sensitive information in /proc.
290 * ptrace_attach denies several cases that /proc allows
291 * because setting up the necessary parent/child relationship
292 * or halting the specified task is impossible.
295 /* Don't let security modules deny introspection */
296 if (same_thread_group(task, current))
299 if (mode & PTRACE_MODE_FSCREDS) {
300 caller_uid = cred->fsuid;
301 caller_gid = cred->fsgid;
304 * Using the euid would make more sense here, but something
305 * in userland might rely on the old behavior, and this
306 * shouldn't be a security problem since
307 * PTRACE_MODE_REALCREDS implies that the caller explicitly
308 * used a syscall that requests access to another process
309 * (and not a filesystem syscall to procfs).
311 caller_uid = cred->uid;
312 caller_gid = cred->gid;
314 tcred = __task_cred(task);
315 if (uid_eq(caller_uid, tcred->euid) &&
316 uid_eq(caller_uid, tcred->suid) &&
317 uid_eq(caller_uid, tcred->uid) &&
318 gid_eq(caller_gid, tcred->egid) &&
319 gid_eq(caller_gid, tcred->sgid) &&
320 gid_eq(caller_gid, tcred->gid))
322 if (ptrace_has_cap(tcred->user_ns, mode))
329 * If a task drops privileges and becomes nondumpable (through a syscall
330 * like setresuid()) while we are trying to access it, we must ensure
331 * that the dumpability is read after the credentials; otherwise,
332 * we may be able to attach to a task that we shouldn't be able to
333 * attach to (as if the task had dropped privileges without becoming
335 * Pairs with a write barrier in commit_creds().
340 ((get_dumpable(mm) != SUID_DUMP_USER) &&
341 !ptrace_has_cap(mm->user_ns, mode)))
344 return security_ptrace_access_check(task, mode);
347 bool ptrace_may_access(struct task_struct *task, unsigned int mode)
351 err = __ptrace_may_access(task, mode);
356 static int ptrace_attach(struct task_struct *task, long request,
360 bool seize = (request == PTRACE_SEIZE);
367 if (flags & ~(unsigned long)PTRACE_O_MASK)
369 flags = PT_PTRACED | PT_SEIZED | (flags << PT_OPT_FLAG_SHIFT);
377 if (unlikely(task->flags & PF_KTHREAD))
379 if (same_thread_group(task, current))
383 * Protect exec's credential calculations against our interference;
384 * SUID, SGID and LSM creds get determined differently
387 retval = -ERESTARTNOINTR;
388 if (mutex_lock_interruptible(&task->signal->cred_guard_mutex))
392 retval = __ptrace_may_access(task, PTRACE_MODE_ATTACH_REALCREDS);
397 write_lock_irq(&tasklist_lock);
399 if (unlikely(task->exit_state))
400 goto unlock_tasklist;
402 goto unlock_tasklist;
406 task->ptrace = flags;
408 ptrace_link(task, current);
410 /* SEIZE doesn't trap tracee on attach */
412 send_sig_info(SIGSTOP, SEND_SIG_PRIV, task);
414 spin_lock(&task->sighand->siglock);
417 * If the task is already STOPPED, set JOBCTL_TRAP_STOP and
418 * TRAPPING, and kick it so that it transits to TRACED. TRAPPING
419 * will be cleared if the child completes the transition or any
420 * event which clears the group stop states happens. We'll wait
421 * for the transition to complete before returning from this
424 * This hides STOPPED -> RUNNING -> TRACED transition from the
425 * attaching thread but a different thread in the same group can
426 * still observe the transient RUNNING state. IOW, if another
427 * thread's WNOHANG wait(2) on the stopped tracee races against
428 * ATTACH, the wait(2) may fail due to the transient RUNNING.
430 * The following task_is_stopped() test is safe as both transitions
431 * in and out of STOPPED are protected by siglock.
433 if (task_is_stopped(task) &&
434 task_set_jobctl_pending(task, JOBCTL_TRAP_STOP | JOBCTL_TRAPPING))
435 signal_wake_up_state(task, __TASK_STOPPED);
437 spin_unlock(&task->sighand->siglock);
441 write_unlock_irq(&tasklist_lock);
443 mutex_unlock(&task->signal->cred_guard_mutex);
447 * We do not bother to change retval or clear JOBCTL_TRAPPING
448 * if wait_on_bit() was interrupted by SIGKILL. The tracer will
449 * not return to user-mode, it will exit and clear this bit in
450 * __ptrace_unlink() if it wasn't already cleared by the tracee;
451 * and until then nobody can ptrace this task.
453 wait_on_bit(&task->jobctl, JOBCTL_TRAPPING_BIT, TASK_KILLABLE);
454 proc_ptrace_connector(task, PTRACE_ATTACH);
461 * ptrace_traceme -- helper for PTRACE_TRACEME
463 * Performs checks and sets PT_PTRACED.
464 * Should be used by all ptrace implementations for PTRACE_TRACEME.
466 static int ptrace_traceme(void)
470 write_lock_irq(&tasklist_lock);
471 /* Are we already being traced? */
472 if (!current->ptrace) {
473 ret = security_ptrace_traceme(current->parent);
475 * Check PF_EXITING to ensure ->real_parent has not passed
476 * exit_ptrace(). Otherwise we don't report the error but
477 * pretend ->real_parent untraces us right after return.
479 if (!ret && !(current->real_parent->flags & PF_EXITING)) {
480 current->ptrace = PT_PTRACED;
481 ptrace_link(current, current->real_parent);
484 write_unlock_irq(&tasklist_lock);
490 * Called with irqs disabled, returns true if childs should reap themselves.
492 static int ignoring_children(struct sighand_struct *sigh)
495 spin_lock(&sigh->siglock);
496 ret = (sigh->action[SIGCHLD-1].sa.sa_handler == SIG_IGN) ||
497 (sigh->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT);
498 spin_unlock(&sigh->siglock);
503 * Called with tasklist_lock held for writing.
504 * Unlink a traced task, and clean it up if it was a traced zombie.
505 * Return true if it needs to be reaped with release_task().
506 * (We can't call release_task() here because we already hold tasklist_lock.)
508 * If it's a zombie, our attachedness prevented normal parent notification
509 * or self-reaping. Do notification now if it would have happened earlier.
510 * If it should reap itself, return true.
512 * If it's our own child, there is no notification to do. But if our normal
513 * children self-reap, then this child was prevented by ptrace and we must
514 * reap it now, in that case we must also wake up sub-threads sleeping in
517 static bool __ptrace_detach(struct task_struct *tracer, struct task_struct *p)
523 if (p->exit_state != EXIT_ZOMBIE)
526 dead = !thread_group_leader(p);
528 if (!dead && thread_group_empty(p)) {
529 if (!same_thread_group(p->real_parent, tracer))
530 dead = do_notify_parent(p, p->exit_signal);
531 else if (ignoring_children(tracer->sighand)) {
532 __wake_up_parent(p, tracer);
536 /* Mark it as in the process of being reaped. */
538 p->exit_state = EXIT_DEAD;
542 static int ptrace_detach(struct task_struct *child, unsigned int data)
544 if (!valid_signal(data))
547 /* Architecture-specific hardware disable .. */
548 ptrace_disable(child);
550 write_lock_irq(&tasklist_lock);
552 * We rely on ptrace_freeze_traced(). It can't be killed and
553 * untraced by another thread, it can't be a zombie.
555 WARN_ON(!child->ptrace || child->exit_state);
557 * tasklist_lock avoids the race with wait_task_stopped(), see
558 * the comment in ptrace_resume().
560 child->exit_code = data;
561 __ptrace_detach(current, child);
562 write_unlock_irq(&tasklist_lock);
564 proc_ptrace_connector(child, PTRACE_DETACH);
570 * Detach all tasks we were using ptrace on. Called with tasklist held
573 void exit_ptrace(struct task_struct *tracer, struct list_head *dead)
575 struct task_struct *p, *n;
577 list_for_each_entry_safe(p, n, &tracer->ptraced, ptrace_entry) {
578 if (unlikely(p->ptrace & PT_EXITKILL))
579 send_sig_info(SIGKILL, SEND_SIG_PRIV, p);
581 if (__ptrace_detach(tracer, p))
582 list_add(&p->ptrace_entry, dead);
586 int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len)
592 int this_len, retval;
594 this_len = (len > sizeof(buf)) ? sizeof(buf) : len;
595 retval = ptrace_access_vm(tsk, src, buf, this_len, FOLL_FORCE);
602 if (copy_to_user(dst, buf, retval))
612 int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len)
618 int this_len, retval;
620 this_len = (len > sizeof(buf)) ? sizeof(buf) : len;
621 if (copy_from_user(buf, src, this_len))
623 retval = ptrace_access_vm(tsk, dst, buf, this_len,
624 FOLL_FORCE | FOLL_WRITE);
638 static int ptrace_setoptions(struct task_struct *child, unsigned long data)
642 if (data & ~(unsigned long)PTRACE_O_MASK)
645 if (unlikely(data & PTRACE_O_SUSPEND_SECCOMP)) {
646 if (!IS_ENABLED(CONFIG_CHECKPOINT_RESTORE) ||
647 !IS_ENABLED(CONFIG_SECCOMP))
650 if (!capable(CAP_SYS_ADMIN))
653 if (seccomp_mode(¤t->seccomp) != SECCOMP_MODE_DISABLED ||
654 current->ptrace & PT_SUSPEND_SECCOMP)
658 /* Avoid intermediate state when all opts are cleared */
659 flags = child->ptrace;
660 flags &= ~(PTRACE_O_MASK << PT_OPT_FLAG_SHIFT);
661 flags |= (data << PT_OPT_FLAG_SHIFT);
662 child->ptrace = flags;
667 static int ptrace_getsiginfo(struct task_struct *child, kernel_siginfo_t *info)
672 if (lock_task_sighand(child, &flags)) {
674 if (likely(child->last_siginfo != NULL)) {
675 copy_siginfo(info, child->last_siginfo);
678 unlock_task_sighand(child, &flags);
683 static int ptrace_setsiginfo(struct task_struct *child, const kernel_siginfo_t *info)
688 if (lock_task_sighand(child, &flags)) {
690 if (likely(child->last_siginfo != NULL)) {
691 copy_siginfo(child->last_siginfo, info);
694 unlock_task_sighand(child, &flags);
699 static int ptrace_peek_siginfo(struct task_struct *child,
703 struct ptrace_peeksiginfo_args arg;
704 struct sigpending *pending;
708 ret = copy_from_user(&arg, (void __user *) addr,
709 sizeof(struct ptrace_peeksiginfo_args));
713 if (arg.flags & ~PTRACE_PEEKSIGINFO_SHARED)
714 return -EINVAL; /* unknown flags */
719 /* Ensure arg.off fits in an unsigned long */
720 if (arg.off > ULONG_MAX)
723 if (arg.flags & PTRACE_PEEKSIGINFO_SHARED)
724 pending = &child->signal->shared_pending;
726 pending = &child->pending;
728 for (i = 0; i < arg.nr; ) {
729 kernel_siginfo_t info;
730 unsigned long off = arg.off + i;
733 spin_lock_irq(&child->sighand->siglock);
734 list_for_each_entry(q, &pending->list, list) {
737 copy_siginfo(&info, &q->info);
741 spin_unlock_irq(&child->sighand->siglock);
743 if (!found) /* beyond the end of the list */
747 if (unlikely(in_compat_syscall())) {
748 compat_siginfo_t __user *uinfo = compat_ptr(data);
750 if (copy_siginfo_to_user32(uinfo, &info)) {
758 siginfo_t __user *uinfo = (siginfo_t __user *) data;
760 if (copy_siginfo_to_user(uinfo, &info)) {
766 data += sizeof(siginfo_t);
769 if (signal_pending(current))
781 #ifdef PTRACE_SINGLESTEP
782 #define is_singlestep(request) ((request) == PTRACE_SINGLESTEP)
784 #define is_singlestep(request) 0
787 #ifdef PTRACE_SINGLEBLOCK
788 #define is_singleblock(request) ((request) == PTRACE_SINGLEBLOCK)
790 #define is_singleblock(request) 0
794 #define is_sysemu_singlestep(request) ((request) == PTRACE_SYSEMU_SINGLESTEP)
796 #define is_sysemu_singlestep(request) 0
799 static int ptrace_resume(struct task_struct *child, long request,
804 if (!valid_signal(data))
807 if (request == PTRACE_SYSCALL)
808 set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
810 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
812 #ifdef TIF_SYSCALL_EMU
813 if (request == PTRACE_SYSEMU || request == PTRACE_SYSEMU_SINGLESTEP)
814 set_tsk_thread_flag(child, TIF_SYSCALL_EMU);
816 clear_tsk_thread_flag(child, TIF_SYSCALL_EMU);
819 if (is_singleblock(request)) {
820 if (unlikely(!arch_has_block_step()))
822 user_enable_block_step(child);
823 } else if (is_singlestep(request) || is_sysemu_singlestep(request)) {
824 if (unlikely(!arch_has_single_step()))
826 user_enable_single_step(child);
828 user_disable_single_step(child);
832 * Change ->exit_code and ->state under siglock to avoid the race
833 * with wait_task_stopped() in between; a non-zero ->exit_code will
834 * wrongly look like another report from tracee.
836 * Note that we need siglock even if ->exit_code == data and/or this
837 * status was not reported yet, the new status must not be cleared by
838 * wait_task_stopped() after resume.
840 * If data == 0 we do not care if wait_task_stopped() reports the old
841 * status and clears the code too; this can't race with the tracee, it
842 * takes siglock after resume.
844 need_siglock = data && !thread_group_empty(current);
846 spin_lock_irq(&child->sighand->siglock);
847 child->exit_code = data;
848 wake_up_state(child, __TASK_TRACED);
850 spin_unlock_irq(&child->sighand->siglock);
855 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
857 static const struct user_regset *
858 find_regset(const struct user_regset_view *view, unsigned int type)
860 const struct user_regset *regset;
863 for (n = 0; n < view->n; ++n) {
864 regset = view->regsets + n;
865 if (regset->core_note_type == type)
872 static int ptrace_regset(struct task_struct *task, int req, unsigned int type,
875 const struct user_regset_view *view = task_user_regset_view(task);
876 const struct user_regset *regset = find_regset(view, type);
879 if (!regset || (kiov->iov_len % regset->size) != 0)
882 regset_no = regset - view->regsets;
883 kiov->iov_len = min(kiov->iov_len,
884 (__kernel_size_t) (regset->n * regset->size));
886 if (req == PTRACE_GETREGSET)
887 return copy_regset_to_user(task, view, regset_no, 0,
888 kiov->iov_len, kiov->iov_base);
890 return copy_regset_from_user(task, view, regset_no, 0,
891 kiov->iov_len, kiov->iov_base);
895 * This is declared in linux/regset.h and defined in machine-dependent
896 * code. We put the export here, near the primary machine-neutral use,
897 * to ensure no machine forgets it.
899 EXPORT_SYMBOL_GPL(task_user_regset_view);
902 int ptrace_request(struct task_struct *child, long request,
903 unsigned long addr, unsigned long data)
905 bool seized = child->ptrace & PT_SEIZED;
907 kernel_siginfo_t siginfo, *si;
908 void __user *datavp = (void __user *) data;
909 unsigned long __user *datalp = datavp;
913 case PTRACE_PEEKTEXT:
914 case PTRACE_PEEKDATA:
915 return generic_ptrace_peekdata(child, addr, data);
916 case PTRACE_POKETEXT:
917 case PTRACE_POKEDATA:
918 return generic_ptrace_pokedata(child, addr, data);
920 #ifdef PTRACE_OLDSETOPTIONS
921 case PTRACE_OLDSETOPTIONS:
923 case PTRACE_SETOPTIONS:
924 ret = ptrace_setoptions(child, data);
926 case PTRACE_GETEVENTMSG:
927 ret = put_user(child->ptrace_message, datalp);
930 case PTRACE_PEEKSIGINFO:
931 ret = ptrace_peek_siginfo(child, addr, data);
934 case PTRACE_GETSIGINFO:
935 ret = ptrace_getsiginfo(child, &siginfo);
937 ret = copy_siginfo_to_user(datavp, &siginfo);
940 case PTRACE_SETSIGINFO:
941 ret = copy_siginfo_from_user(&siginfo, datavp);
943 ret = ptrace_setsiginfo(child, &siginfo);
946 case PTRACE_GETSIGMASK: {
949 if (addr != sizeof(sigset_t)) {
954 if (test_tsk_restore_sigmask(child))
955 mask = &child->saved_sigmask;
957 mask = &child->blocked;
959 if (copy_to_user(datavp, mask, sizeof(sigset_t)))
967 case PTRACE_SETSIGMASK: {
970 if (addr != sizeof(sigset_t)) {
975 if (copy_from_user(&new_set, datavp, sizeof(sigset_t))) {
980 sigdelsetmask(&new_set, sigmask(SIGKILL)|sigmask(SIGSTOP));
983 * Every thread does recalc_sigpending() after resume, so
984 * retarget_shared_pending() and recalc_sigpending() are not
987 spin_lock_irq(&child->sighand->siglock);
988 child->blocked = new_set;
989 spin_unlock_irq(&child->sighand->siglock);
991 clear_tsk_restore_sigmask(child);
997 case PTRACE_INTERRUPT:
999 * Stop tracee without any side-effect on signal or job
1000 * control. At least one trap is guaranteed to happen
1001 * after this request. If @child is already trapped, the
1002 * current trap is not disturbed and another trap will
1003 * happen after the current trap is ended with PTRACE_CONT.
1005 * The actual trap might not be PTRACE_EVENT_STOP trap but
1006 * the pending condition is cleared regardless.
1008 if (unlikely(!seized || !lock_task_sighand(child, &flags)))
1012 * INTERRUPT doesn't disturb existing trap sans one
1013 * exception. If ptracer issued LISTEN for the current
1014 * STOP, this INTERRUPT should clear LISTEN and re-trap
1017 if (likely(task_set_jobctl_pending(child, JOBCTL_TRAP_STOP)))
1018 ptrace_signal_wake_up(child, child->jobctl & JOBCTL_LISTENING);
1020 unlock_task_sighand(child, &flags);
1026 * Listen for events. Tracee must be in STOP. It's not
1027 * resumed per-se but is not considered to be in TRACED by
1028 * wait(2) or ptrace(2). If an async event (e.g. group
1029 * stop state change) happens, tracee will enter STOP trap
1030 * again. Alternatively, ptracer can issue INTERRUPT to
1031 * finish listening and re-trap tracee into STOP.
1033 if (unlikely(!seized || !lock_task_sighand(child, &flags)))
1036 si = child->last_siginfo;
1037 if (likely(si && (si->si_code >> 8) == PTRACE_EVENT_STOP)) {
1038 child->jobctl |= JOBCTL_LISTENING;
1040 * If NOTIFY is set, it means event happened between
1041 * start of this trap and now. Trigger re-trap.
1043 if (child->jobctl & JOBCTL_TRAP_NOTIFY)
1044 ptrace_signal_wake_up(child, true);
1047 unlock_task_sighand(child, &flags);
1050 case PTRACE_DETACH: /* detach a process that was attached. */
1051 ret = ptrace_detach(child, data);
1054 #ifdef CONFIG_BINFMT_ELF_FDPIC
1055 case PTRACE_GETFDPIC: {
1056 struct mm_struct *mm = get_task_mm(child);
1057 unsigned long tmp = 0;
1064 case PTRACE_GETFDPIC_EXEC:
1065 tmp = mm->context.exec_fdpic_loadmap;
1067 case PTRACE_GETFDPIC_INTERP:
1068 tmp = mm->context.interp_fdpic_loadmap;
1075 ret = put_user(tmp, datalp);
1080 #ifdef PTRACE_SINGLESTEP
1081 case PTRACE_SINGLESTEP:
1083 #ifdef PTRACE_SINGLEBLOCK
1084 case PTRACE_SINGLEBLOCK:
1086 #ifdef PTRACE_SYSEMU
1088 case PTRACE_SYSEMU_SINGLESTEP:
1090 case PTRACE_SYSCALL:
1092 return ptrace_resume(child, request, data);
1095 if (child->exit_state) /* already dead */
1097 return ptrace_resume(child, request, SIGKILL);
1099 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
1100 case PTRACE_GETREGSET:
1101 case PTRACE_SETREGSET: {
1103 struct iovec __user *uiov = datavp;
1105 if (!access_ok(uiov, sizeof(*uiov)))
1108 if (__get_user(kiov.iov_base, &uiov->iov_base) ||
1109 __get_user(kiov.iov_len, &uiov->iov_len))
1112 ret = ptrace_regset(child, request, addr, &kiov);
1114 ret = __put_user(kiov.iov_len, &uiov->iov_len);
1119 case PTRACE_SECCOMP_GET_FILTER:
1120 ret = seccomp_get_filter(child, addr, datavp);
1123 case PTRACE_SECCOMP_GET_METADATA:
1124 ret = seccomp_get_metadata(child, addr, datavp);
1134 #ifndef arch_ptrace_attach
1135 #define arch_ptrace_attach(child) do { } while (0)
1138 SYSCALL_DEFINE4(ptrace, long, request, long, pid, unsigned long, addr,
1139 unsigned long, data)
1141 struct task_struct *child;
1144 if (request == PTRACE_TRACEME) {
1145 ret = ptrace_traceme();
1147 arch_ptrace_attach(current);
1151 child = find_get_task_by_vpid(pid);
1157 if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) {
1158 ret = ptrace_attach(child, request, addr, data);
1160 * Some architectures need to do book-keeping after
1164 arch_ptrace_attach(child);
1165 goto out_put_task_struct;
1168 ret = ptrace_check_attach(child, request == PTRACE_KILL ||
1169 request == PTRACE_INTERRUPT);
1171 goto out_put_task_struct;
1173 ret = arch_ptrace(child, request, addr, data);
1174 if (ret || request != PTRACE_DETACH)
1175 ptrace_unfreeze_traced(child);
1177 out_put_task_struct:
1178 put_task_struct(child);
1183 int generic_ptrace_peekdata(struct task_struct *tsk, unsigned long addr,
1189 copied = ptrace_access_vm(tsk, addr, &tmp, sizeof(tmp), FOLL_FORCE);
1190 if (copied != sizeof(tmp))
1192 return put_user(tmp, (unsigned long __user *)data);
1195 int generic_ptrace_pokedata(struct task_struct *tsk, unsigned long addr,
1200 copied = ptrace_access_vm(tsk, addr, &data, sizeof(data),
1201 FOLL_FORCE | FOLL_WRITE);
1202 return (copied == sizeof(data)) ? 0 : -EIO;
1205 #if defined CONFIG_COMPAT
1207 int compat_ptrace_request(struct task_struct *child, compat_long_t request,
1208 compat_ulong_t addr, compat_ulong_t data)
1210 compat_ulong_t __user *datap = compat_ptr(data);
1211 compat_ulong_t word;
1212 kernel_siginfo_t siginfo;
1216 case PTRACE_PEEKTEXT:
1217 case PTRACE_PEEKDATA:
1218 ret = ptrace_access_vm(child, addr, &word, sizeof(word),
1220 if (ret != sizeof(word))
1223 ret = put_user(word, datap);
1226 case PTRACE_POKETEXT:
1227 case PTRACE_POKEDATA:
1228 ret = ptrace_access_vm(child, addr, &data, sizeof(data),
1229 FOLL_FORCE | FOLL_WRITE);
1230 ret = (ret != sizeof(data) ? -EIO : 0);
1233 case PTRACE_GETEVENTMSG:
1234 ret = put_user((compat_ulong_t) child->ptrace_message, datap);
1237 case PTRACE_GETSIGINFO:
1238 ret = ptrace_getsiginfo(child, &siginfo);
1240 ret = copy_siginfo_to_user32(
1241 (struct compat_siginfo __user *) datap,
1245 case PTRACE_SETSIGINFO:
1246 ret = copy_siginfo_from_user32(
1247 &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(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 */