2 * linux/kernel/ptrace.c
4 * (C) Copyright 1999 Linus Torvalds
6 * Common interfaces for "ptrace()" which we do not want
7 * to continually duplicate across every architecture.
10 #include <linux/capability.h>
11 #include <linux/export.h>
12 #include <linux/sched.h>
13 #include <linux/errno.h>
15 #include <linux/highmem.h>
16 #include <linux/pagemap.h>
17 #include <linux/ptrace.h>
18 #include <linux/security.h>
19 #include <linux/signal.h>
20 #include <linux/uio.h>
21 #include <linux/audit.h>
22 #include <linux/pid_namespace.h>
23 #include <linux/syscalls.h>
24 #include <linux/uaccess.h>
25 #include <linux/regset.h>
26 #include <linux/hw_breakpoint.h>
27 #include <linux/cn_proc.h>
28 #include <linux/compat.h>
31 void __ptrace_link(struct task_struct *child, struct task_struct *new_parent,
32 const struct cred *ptracer_cred)
34 BUG_ON(!list_empty(&child->ptrace_entry));
35 list_add(&child->ptrace_entry, &new_parent->ptraced);
36 child->parent = new_parent;
37 child->ptracer_cred = get_cred(ptracer_cred);
41 * ptrace a task: make the debugger its new parent and
42 * move it to the ptrace list.
44 * Must be called with the tasklist lock write-held.
46 static void ptrace_link(struct task_struct *child, struct task_struct *new_parent)
48 __ptrace_link(child, new_parent, current_cred());
52 * __ptrace_unlink - unlink ptracee and restore its execution state
53 * @child: ptracee to be unlinked
55 * Remove @child from the ptrace list, move it back to the original parent,
56 * and restore the execution state so that it conforms to the group stop
59 * Unlinking can happen via two paths - explicit PTRACE_DETACH or ptracer
60 * exiting. For PTRACE_DETACH, unless the ptracee has been killed between
61 * ptrace_check_attach() and here, it's guaranteed to be in TASK_TRACED.
62 * If the ptracer is exiting, the ptracee can be in any state.
64 * After detach, the ptracee should be in a state which conforms to the
65 * group stop. If the group is stopped or in the process of stopping, the
66 * ptracee should be put into TASK_STOPPED; otherwise, it should be woken
67 * up from TASK_TRACED.
69 * If the ptracee is in TASK_TRACED and needs to be moved to TASK_STOPPED,
70 * it goes through TRACED -> RUNNING -> STOPPED transition which is similar
71 * to but in the opposite direction of what happens while attaching to a
72 * stopped task. However, in this direction, the intermediate RUNNING
73 * state is not hidden even from the current ptracer and if it immediately
74 * re-attaches and performs a WNOHANG wait(2), it may fail.
77 * write_lock_irq(tasklist_lock)
79 void __ptrace_unlink(struct task_struct *child)
81 const struct cred *old_cred;
82 BUG_ON(!child->ptrace);
85 child->parent = child->real_parent;
86 list_del_init(&child->ptrace_entry);
87 old_cred = child->ptracer_cred;
88 child->ptracer_cred = NULL;
91 spin_lock(&child->sighand->siglock);
94 * Clear all pending traps and TRAPPING. TRAPPING should be
95 * cleared regardless of JOBCTL_STOP_PENDING. Do it explicitly.
97 task_clear_jobctl_pending(child, JOBCTL_TRAP_MASK);
98 task_clear_jobctl_trapping(child);
101 * Reinstate JOBCTL_STOP_PENDING if group stop is in effect and
104 if (!(child->flags & PF_EXITING) &&
105 (child->signal->flags & SIGNAL_STOP_STOPPED ||
106 child->signal->group_stop_count)) {
107 child->jobctl |= JOBCTL_STOP_PENDING;
110 * This is only possible if this thread was cloned by the
111 * traced task running in the stopped group, set the signal
112 * for the future reports.
113 * FIXME: we should change ptrace_init_task() to handle this
116 if (!(child->jobctl & JOBCTL_STOP_SIGMASK))
117 child->jobctl |= SIGSTOP;
121 * If transition to TASK_STOPPED is pending or in TASK_TRACED, kick
122 * @child in the butt. Note that @resume should be used iff @child
123 * is in TASK_TRACED; otherwise, we might unduly disrupt
124 * TASK_KILLABLE sleeps.
126 if (child->jobctl & JOBCTL_STOP_PENDING || task_is_traced(child))
127 ptrace_signal_wake_up(child, true);
129 spin_unlock(&child->sighand->siglock);
132 /* Ensure that nothing can wake it up, even SIGKILL */
133 static bool ptrace_freeze_traced(struct task_struct *task)
137 /* Lockless, nobody but us can set this flag */
138 if (task->jobctl & JOBCTL_LISTENING)
141 spin_lock_irq(&task->sighand->siglock);
142 if (task_is_traced(task) && !__fatal_signal_pending(task)) {
143 task->state = __TASK_TRACED;
146 spin_unlock_irq(&task->sighand->siglock);
151 static void ptrace_unfreeze_traced(struct task_struct *task)
153 if (task->state != __TASK_TRACED)
156 WARN_ON(!task->ptrace || task->parent != current);
159 * PTRACE_LISTEN can allow ptrace_trap_notify to wake us up remotely.
160 * Recheck state under the lock to close this race.
162 spin_lock_irq(&task->sighand->siglock);
163 if (task->state == __TASK_TRACED) {
164 if (__fatal_signal_pending(task))
165 wake_up_state(task, __TASK_TRACED);
167 task->state = TASK_TRACED;
169 spin_unlock_irq(&task->sighand->siglock);
173 * ptrace_check_attach - check whether ptracee is ready for ptrace operation
174 * @child: ptracee to check for
175 * @ignore_state: don't check whether @child is currently %TASK_TRACED
177 * Check whether @child is being ptraced by %current and ready for further
178 * ptrace operations. If @ignore_state is %false, @child also should be in
179 * %TASK_TRACED state and on return the child is guaranteed to be traced
180 * and not executing. If @ignore_state is %true, @child can be in any
184 * Grabs and releases tasklist_lock and @child->sighand->siglock.
187 * 0 on success, -ESRCH if %child is not ready.
189 static int ptrace_check_attach(struct task_struct *child, bool ignore_state)
194 * We take the read lock around doing both checks to close a
195 * possible race where someone else was tracing our child and
196 * detached between these two checks. After this locked check,
197 * we are sure that this is our traced child and that can only
198 * be changed by us so it's not changing right after this.
200 read_lock(&tasklist_lock);
201 if (child->ptrace && child->parent == current) {
202 WARN_ON(child->state == __TASK_TRACED);
204 * child->sighand can't be NULL, release_task()
205 * does ptrace_unlink() before __exit_signal().
207 if (ignore_state || ptrace_freeze_traced(child))
210 read_unlock(&tasklist_lock);
212 if (!ret && !ignore_state) {
213 if (!wait_task_inactive(child, __TASK_TRACED)) {
215 * This can only happen if may_ptrace_stop() fails and
216 * ptrace_stop() changes ->state back to TASK_RUNNING,
217 * so we should not worry about leaking __TASK_TRACED.
219 WARN_ON(child->state == __TASK_TRACED);
227 static int ptrace_has_cap(struct user_namespace *ns, unsigned int mode)
229 if (mode & PTRACE_MODE_SCHED)
232 if (mode & PTRACE_MODE_NOAUDIT)
233 return has_ns_capability_noaudit(current, ns, CAP_SYS_PTRACE);
235 return has_ns_capability(current, ns, CAP_SYS_PTRACE);
238 /* Returns 0 on success, -errno on denial. */
239 static int __ptrace_may_access(struct task_struct *task, unsigned int mode)
241 const struct cred *cred = current_cred(), *tcred;
242 struct mm_struct *mm;
246 if (!(mode & PTRACE_MODE_FSCREDS) == !(mode & PTRACE_MODE_REALCREDS)) {
247 WARN(1, "denying ptrace access check without PTRACE_MODE_*CREDS\n");
251 /* May we inspect the given task?
252 * This check is used both for attaching with ptrace
253 * and for allowing access to sensitive information in /proc.
255 * ptrace_attach denies several cases that /proc allows
256 * because setting up the necessary parent/child relationship
257 * or halting the specified task is impossible.
260 /* Don't let security modules deny introspection */
261 if (same_thread_group(task, current))
264 if (mode & PTRACE_MODE_FSCREDS) {
265 caller_uid = cred->fsuid;
266 caller_gid = cred->fsgid;
269 * Using the euid would make more sense here, but something
270 * in userland might rely on the old behavior, and this
271 * shouldn't be a security problem since
272 * PTRACE_MODE_REALCREDS implies that the caller explicitly
273 * used a syscall that requests access to another process
274 * (and not a filesystem syscall to procfs).
276 caller_uid = cred->uid;
277 caller_gid = cred->gid;
279 tcred = __task_cred(task);
280 if (uid_eq(caller_uid, tcred->euid) &&
281 uid_eq(caller_uid, tcred->suid) &&
282 uid_eq(caller_uid, tcred->uid) &&
283 gid_eq(caller_gid, tcred->egid) &&
284 gid_eq(caller_gid, tcred->sgid) &&
285 gid_eq(caller_gid, tcred->gid))
287 if (ptrace_has_cap(tcred->user_ns, mode))
294 * If a task drops privileges and becomes nondumpable (through a syscall
295 * like setresuid()) while we are trying to access it, we must ensure
296 * that the dumpability is read after the credentials; otherwise,
297 * we may be able to attach to a task that we shouldn't be able to
298 * attach to (as if the task had dropped privileges without becoming
300 * Pairs with a write barrier in commit_creds().
305 ((get_dumpable(mm) != SUID_DUMP_USER) &&
306 !ptrace_has_cap(mm->user_ns, mode)))
309 if (mode & PTRACE_MODE_SCHED)
311 return security_ptrace_access_check(task, mode);
314 bool ptrace_may_access_sched(struct task_struct *task, unsigned int mode)
316 return __ptrace_may_access(task, mode | PTRACE_MODE_SCHED);
319 bool ptrace_may_access(struct task_struct *task, unsigned int mode)
323 err = __ptrace_may_access(task, mode);
328 static int ptrace_attach(struct task_struct *task, long request,
332 bool seize = (request == PTRACE_SEIZE);
339 if (flags & ~(unsigned long)PTRACE_O_MASK)
341 flags = PT_PTRACED | PT_SEIZED | (flags << PT_OPT_FLAG_SHIFT);
349 if (unlikely(task->flags & PF_KTHREAD))
351 if (same_thread_group(task, current))
355 * Protect exec's credential calculations against our interference;
356 * SUID, SGID and LSM creds get determined differently
359 retval = -ERESTARTNOINTR;
360 if (mutex_lock_interruptible(&task->signal->cred_guard_mutex))
364 retval = __ptrace_may_access(task, PTRACE_MODE_ATTACH_REALCREDS);
369 write_lock_irq(&tasklist_lock);
371 if (unlikely(task->exit_state))
372 goto unlock_tasklist;
374 goto unlock_tasklist;
378 task->ptrace = flags;
380 ptrace_link(task, current);
382 /* SEIZE doesn't trap tracee on attach */
384 send_sig_info(SIGSTOP, SEND_SIG_FORCED, task);
386 spin_lock(&task->sighand->siglock);
389 * If the task is already STOPPED, set JOBCTL_TRAP_STOP and
390 * TRAPPING, and kick it so that it transits to TRACED. TRAPPING
391 * will be cleared if the child completes the transition or any
392 * event which clears the group stop states happens. We'll wait
393 * for the transition to complete before returning from this
396 * This hides STOPPED -> RUNNING -> TRACED transition from the
397 * attaching thread but a different thread in the same group can
398 * still observe the transient RUNNING state. IOW, if another
399 * thread's WNOHANG wait(2) on the stopped tracee races against
400 * ATTACH, the wait(2) may fail due to the transient RUNNING.
402 * The following task_is_stopped() test is safe as both transitions
403 * in and out of STOPPED are protected by siglock.
405 if (task_is_stopped(task) &&
406 task_set_jobctl_pending(task, JOBCTL_TRAP_STOP | JOBCTL_TRAPPING))
407 signal_wake_up_state(task, __TASK_STOPPED);
409 spin_unlock(&task->sighand->siglock);
413 write_unlock_irq(&tasklist_lock);
415 mutex_unlock(&task->signal->cred_guard_mutex);
418 wait_on_bit(&task->jobctl, JOBCTL_TRAPPING_BIT,
419 TASK_UNINTERRUPTIBLE);
420 proc_ptrace_connector(task, PTRACE_ATTACH);
427 * ptrace_traceme -- helper for PTRACE_TRACEME
429 * Performs checks and sets PT_PTRACED.
430 * Should be used by all ptrace implementations for PTRACE_TRACEME.
432 static int ptrace_traceme(void)
436 write_lock_irq(&tasklist_lock);
437 /* Are we already being traced? */
438 if (!current->ptrace) {
439 ret = security_ptrace_traceme(current->parent);
441 * Check PF_EXITING to ensure ->real_parent has not passed
442 * exit_ptrace(). Otherwise we don't report the error but
443 * pretend ->real_parent untraces us right after return.
445 if (!ret && !(current->real_parent->flags & PF_EXITING)) {
446 current->ptrace = PT_PTRACED;
447 ptrace_link(current, current->real_parent);
450 write_unlock_irq(&tasklist_lock);
456 * Called with irqs disabled, returns true if childs should reap themselves.
458 static int ignoring_children(struct sighand_struct *sigh)
461 spin_lock(&sigh->siglock);
462 ret = (sigh->action[SIGCHLD-1].sa.sa_handler == SIG_IGN) ||
463 (sigh->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT);
464 spin_unlock(&sigh->siglock);
469 * Called with tasklist_lock held for writing.
470 * Unlink a traced task, and clean it up if it was a traced zombie.
471 * Return true if it needs to be reaped with release_task().
472 * (We can't call release_task() here because we already hold tasklist_lock.)
474 * If it's a zombie, our attachedness prevented normal parent notification
475 * or self-reaping. Do notification now if it would have happened earlier.
476 * If it should reap itself, return true.
478 * If it's our own child, there is no notification to do. But if our normal
479 * children self-reap, then this child was prevented by ptrace and we must
480 * reap it now, in that case we must also wake up sub-threads sleeping in
483 static bool __ptrace_detach(struct task_struct *tracer, struct task_struct *p)
489 if (p->exit_state != EXIT_ZOMBIE)
492 dead = !thread_group_leader(p);
494 if (!dead && thread_group_empty(p)) {
495 if (!same_thread_group(p->real_parent, tracer))
496 dead = do_notify_parent(p, p->exit_signal);
497 else if (ignoring_children(tracer->sighand)) {
498 __wake_up_parent(p, tracer);
502 /* Mark it as in the process of being reaped. */
504 p->exit_state = EXIT_DEAD;
508 static int ptrace_detach(struct task_struct *child, unsigned int data)
510 if (!valid_signal(data))
513 /* Architecture-specific hardware disable .. */
514 ptrace_disable(child);
515 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
517 write_lock_irq(&tasklist_lock);
519 * We rely on ptrace_freeze_traced(). It can't be killed and
520 * untraced by another thread, it can't be a zombie.
522 WARN_ON(!child->ptrace || child->exit_state);
524 * tasklist_lock avoids the race with wait_task_stopped(), see
525 * the comment in ptrace_resume().
527 child->exit_code = data;
528 __ptrace_detach(current, child);
529 write_unlock_irq(&tasklist_lock);
531 proc_ptrace_connector(child, PTRACE_DETACH);
537 * Detach all tasks we were using ptrace on. Called with tasklist held
540 void exit_ptrace(struct task_struct *tracer, struct list_head *dead)
542 struct task_struct *p, *n;
544 list_for_each_entry_safe(p, n, &tracer->ptraced, ptrace_entry) {
545 if (unlikely(p->ptrace & PT_EXITKILL))
546 send_sig_info(SIGKILL, SEND_SIG_FORCED, p);
548 if (__ptrace_detach(tracer, p))
549 list_add(&p->ptrace_entry, dead);
553 int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len)
559 int this_len, retval;
561 this_len = (len > sizeof(buf)) ? sizeof(buf) : len;
562 retval = access_process_vm(tsk, src, buf, this_len, 0);
568 if (copy_to_user(dst, buf, retval))
578 int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len)
584 int this_len, retval;
586 this_len = (len > sizeof(buf)) ? sizeof(buf) : len;
587 if (copy_from_user(buf, src, this_len))
589 retval = access_process_vm(tsk, dst, buf, this_len, 1);
603 static int ptrace_setoptions(struct task_struct *child, unsigned long data)
607 if (data & ~(unsigned long)PTRACE_O_MASK)
610 if (unlikely(data & PTRACE_O_SUSPEND_SECCOMP)) {
611 if (!config_enabled(CONFIG_CHECKPOINT_RESTORE) ||
612 !config_enabled(CONFIG_SECCOMP))
615 if (!capable(CAP_SYS_ADMIN))
618 if (seccomp_mode(¤t->seccomp) != SECCOMP_MODE_DISABLED ||
619 current->ptrace & PT_SUSPEND_SECCOMP)
623 /* Avoid intermediate state when all opts are cleared */
624 flags = child->ptrace;
625 flags &= ~(PTRACE_O_MASK << PT_OPT_FLAG_SHIFT);
626 flags |= (data << PT_OPT_FLAG_SHIFT);
627 child->ptrace = flags;
632 static int ptrace_getsiginfo(struct task_struct *child, siginfo_t *info)
637 if (lock_task_sighand(child, &flags)) {
639 if (likely(child->last_siginfo != NULL)) {
640 *info = *child->last_siginfo;
643 unlock_task_sighand(child, &flags);
648 static int ptrace_setsiginfo(struct task_struct *child, const siginfo_t *info)
653 if (lock_task_sighand(child, &flags)) {
655 if (likely(child->last_siginfo != NULL)) {
656 *child->last_siginfo = *info;
659 unlock_task_sighand(child, &flags);
664 static int ptrace_peek_siginfo(struct task_struct *child,
668 struct ptrace_peeksiginfo_args arg;
669 struct sigpending *pending;
673 ret = copy_from_user(&arg, (void __user *) addr,
674 sizeof(struct ptrace_peeksiginfo_args));
678 if (arg.flags & ~PTRACE_PEEKSIGINFO_SHARED)
679 return -EINVAL; /* unknown flags */
684 /* Ensure arg.off fits in an unsigned long */
685 if (arg.off > ULONG_MAX)
688 if (arg.flags & PTRACE_PEEKSIGINFO_SHARED)
689 pending = &child->signal->shared_pending;
691 pending = &child->pending;
693 for (i = 0; i < arg.nr; ) {
695 unsigned long off = arg.off + i;
698 spin_lock_irq(&child->sighand->siglock);
699 list_for_each_entry(q, &pending->list, list) {
702 copy_siginfo(&info, &q->info);
706 spin_unlock_irq(&child->sighand->siglock);
708 if (!found) /* beyond the end of the list */
712 if (unlikely(is_compat_task())) {
713 compat_siginfo_t __user *uinfo = compat_ptr(data);
715 if (copy_siginfo_to_user32(uinfo, &info) ||
716 __put_user(info.si_code, &uinfo->si_code)) {
724 siginfo_t __user *uinfo = (siginfo_t __user *) data;
726 if (copy_siginfo_to_user(uinfo, &info) ||
727 __put_user(info.si_code, &uinfo->si_code)) {
733 data += sizeof(siginfo_t);
736 if (signal_pending(current))
748 #ifdef PTRACE_SINGLESTEP
749 #define is_singlestep(request) ((request) == PTRACE_SINGLESTEP)
751 #define is_singlestep(request) 0
754 #ifdef PTRACE_SINGLEBLOCK
755 #define is_singleblock(request) ((request) == PTRACE_SINGLEBLOCK)
757 #define is_singleblock(request) 0
761 #define is_sysemu_singlestep(request) ((request) == PTRACE_SYSEMU_SINGLESTEP)
763 #define is_sysemu_singlestep(request) 0
766 static int ptrace_resume(struct task_struct *child, long request,
771 if (!valid_signal(data))
774 if (request == PTRACE_SYSCALL)
775 set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
777 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
779 #ifdef TIF_SYSCALL_EMU
780 if (request == PTRACE_SYSEMU || request == PTRACE_SYSEMU_SINGLESTEP)
781 set_tsk_thread_flag(child, TIF_SYSCALL_EMU);
783 clear_tsk_thread_flag(child, TIF_SYSCALL_EMU);
786 if (is_singleblock(request)) {
787 if (unlikely(!arch_has_block_step()))
789 user_enable_block_step(child);
790 } else if (is_singlestep(request) || is_sysemu_singlestep(request)) {
791 if (unlikely(!arch_has_single_step()))
793 user_enable_single_step(child);
795 user_disable_single_step(child);
799 * Change ->exit_code and ->state under siglock to avoid the race
800 * with wait_task_stopped() in between; a non-zero ->exit_code will
801 * wrongly look like another report from tracee.
803 * Note that we need siglock even if ->exit_code == data and/or this
804 * status was not reported yet, the new status must not be cleared by
805 * wait_task_stopped() after resume.
807 * If data == 0 we do not care if wait_task_stopped() reports the old
808 * status and clears the code too; this can't race with the tracee, it
809 * takes siglock after resume.
811 need_siglock = data && !thread_group_empty(current);
813 spin_lock_irq(&child->sighand->siglock);
814 child->exit_code = data;
815 wake_up_state(child, __TASK_TRACED);
817 spin_unlock_irq(&child->sighand->siglock);
822 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
824 static const struct user_regset *
825 find_regset(const struct user_regset_view *view, unsigned int type)
827 const struct user_regset *regset;
830 for (n = 0; n < view->n; ++n) {
831 regset = view->regsets + n;
832 if (regset->core_note_type == type)
839 static int ptrace_regset(struct task_struct *task, int req, unsigned int type,
842 const struct user_regset_view *view = task_user_regset_view(task);
843 const struct user_regset *regset = find_regset(view, type);
846 if (!regset || (kiov->iov_len % regset->size) != 0)
849 regset_no = regset - view->regsets;
850 kiov->iov_len = min(kiov->iov_len,
851 (__kernel_size_t) (regset->n * regset->size));
853 if (req == PTRACE_GETREGSET)
854 return copy_regset_to_user(task, view, regset_no, 0,
855 kiov->iov_len, kiov->iov_base);
857 return copy_regset_from_user(task, view, regset_no, 0,
858 kiov->iov_len, kiov->iov_base);
862 * This is declared in linux/regset.h and defined in machine-dependent
863 * code. We put the export here, near the primary machine-neutral use,
864 * to ensure no machine forgets it.
866 EXPORT_SYMBOL_GPL(task_user_regset_view);
869 int ptrace_request(struct task_struct *child, long request,
870 unsigned long addr, unsigned long data)
872 bool seized = child->ptrace & PT_SEIZED;
874 siginfo_t siginfo, *si;
875 void __user *datavp = (void __user *) data;
876 unsigned long __user *datalp = datavp;
880 case PTRACE_PEEKTEXT:
881 case PTRACE_PEEKDATA:
882 return generic_ptrace_peekdata(child, addr, data);
883 case PTRACE_POKETEXT:
884 case PTRACE_POKEDATA:
885 return generic_ptrace_pokedata(child, addr, data);
887 #ifdef PTRACE_OLDSETOPTIONS
888 case PTRACE_OLDSETOPTIONS:
890 case PTRACE_SETOPTIONS:
891 ret = ptrace_setoptions(child, data);
893 case PTRACE_GETEVENTMSG:
894 ret = put_user(child->ptrace_message, datalp);
897 case PTRACE_PEEKSIGINFO:
898 ret = ptrace_peek_siginfo(child, addr, data);
901 case PTRACE_GETSIGINFO:
902 ret = ptrace_getsiginfo(child, &siginfo);
904 ret = copy_siginfo_to_user(datavp, &siginfo);
907 case PTRACE_SETSIGINFO:
908 if (copy_from_user(&siginfo, datavp, sizeof siginfo))
911 ret = ptrace_setsiginfo(child, &siginfo);
914 case PTRACE_GETSIGMASK:
915 if (addr != sizeof(sigset_t)) {
920 if (copy_to_user(datavp, &child->blocked, sizeof(sigset_t)))
927 case PTRACE_SETSIGMASK: {
930 if (addr != sizeof(sigset_t)) {
935 if (copy_from_user(&new_set, datavp, sizeof(sigset_t))) {
940 sigdelsetmask(&new_set, sigmask(SIGKILL)|sigmask(SIGSTOP));
943 * Every thread does recalc_sigpending() after resume, so
944 * retarget_shared_pending() and recalc_sigpending() are not
947 spin_lock_irq(&child->sighand->siglock);
948 child->blocked = new_set;
949 spin_unlock_irq(&child->sighand->siglock);
955 case PTRACE_INTERRUPT:
957 * Stop tracee without any side-effect on signal or job
958 * control. At least one trap is guaranteed to happen
959 * after this request. If @child is already trapped, the
960 * current trap is not disturbed and another trap will
961 * happen after the current trap is ended with PTRACE_CONT.
963 * The actual trap might not be PTRACE_EVENT_STOP trap but
964 * the pending condition is cleared regardless.
966 if (unlikely(!seized || !lock_task_sighand(child, &flags)))
970 * INTERRUPT doesn't disturb existing trap sans one
971 * exception. If ptracer issued LISTEN for the current
972 * STOP, this INTERRUPT should clear LISTEN and re-trap
975 if (likely(task_set_jobctl_pending(child, JOBCTL_TRAP_STOP)))
976 ptrace_signal_wake_up(child, child->jobctl & JOBCTL_LISTENING);
978 unlock_task_sighand(child, &flags);
984 * Listen for events. Tracee must be in STOP. It's not
985 * resumed per-se but is not considered to be in TRACED by
986 * wait(2) or ptrace(2). If an async event (e.g. group
987 * stop state change) happens, tracee will enter STOP trap
988 * again. Alternatively, ptracer can issue INTERRUPT to
989 * finish listening and re-trap tracee into STOP.
991 if (unlikely(!seized || !lock_task_sighand(child, &flags)))
994 si = child->last_siginfo;
995 if (likely(si && (si->si_code >> 8) == PTRACE_EVENT_STOP)) {
996 child->jobctl |= JOBCTL_LISTENING;
998 * If NOTIFY is set, it means event happened between
999 * start of this trap and now. Trigger re-trap.
1001 if (child->jobctl & JOBCTL_TRAP_NOTIFY)
1002 ptrace_signal_wake_up(child, true);
1005 unlock_task_sighand(child, &flags);
1008 case PTRACE_DETACH: /* detach a process that was attached. */
1009 ret = ptrace_detach(child, data);
1012 #ifdef CONFIG_BINFMT_ELF_FDPIC
1013 case PTRACE_GETFDPIC: {
1014 struct mm_struct *mm = get_task_mm(child);
1015 unsigned long tmp = 0;
1022 case PTRACE_GETFDPIC_EXEC:
1023 tmp = mm->context.exec_fdpic_loadmap;
1025 case PTRACE_GETFDPIC_INTERP:
1026 tmp = mm->context.interp_fdpic_loadmap;
1033 ret = put_user(tmp, datalp);
1038 #ifdef PTRACE_SINGLESTEP
1039 case PTRACE_SINGLESTEP:
1041 #ifdef PTRACE_SINGLEBLOCK
1042 case PTRACE_SINGLEBLOCK:
1044 #ifdef PTRACE_SYSEMU
1046 case PTRACE_SYSEMU_SINGLESTEP:
1048 case PTRACE_SYSCALL:
1050 return ptrace_resume(child, request, data);
1053 if (child->exit_state) /* already dead */
1055 return ptrace_resume(child, request, SIGKILL);
1057 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
1058 case PTRACE_GETREGSET:
1059 case PTRACE_SETREGSET: {
1061 struct iovec __user *uiov = datavp;
1063 if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov)))
1066 if (__get_user(kiov.iov_base, &uiov->iov_base) ||
1067 __get_user(kiov.iov_len, &uiov->iov_len))
1070 ret = ptrace_regset(child, request, addr, &kiov);
1072 ret = __put_user(kiov.iov_len, &uiov->iov_len);
1077 case PTRACE_SECCOMP_GET_FILTER:
1078 ret = seccomp_get_filter(child, addr, datavp);
1088 static struct task_struct *ptrace_get_task_struct(pid_t pid)
1090 struct task_struct *child;
1093 child = find_task_by_vpid(pid);
1095 get_task_struct(child);
1099 return ERR_PTR(-ESRCH);
1103 #ifndef arch_ptrace_attach
1104 #define arch_ptrace_attach(child) do { } while (0)
1107 SYSCALL_DEFINE4(ptrace, long, request, long, pid, unsigned long, addr,
1108 unsigned long, data)
1110 struct task_struct *child;
1113 if (request == PTRACE_TRACEME) {
1114 ret = ptrace_traceme();
1116 arch_ptrace_attach(current);
1120 child = ptrace_get_task_struct(pid);
1121 if (IS_ERR(child)) {
1122 ret = PTR_ERR(child);
1126 if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) {
1127 ret = ptrace_attach(child, request, addr, data);
1129 * Some architectures need to do book-keeping after
1133 arch_ptrace_attach(child);
1134 goto out_put_task_struct;
1137 ret = ptrace_check_attach(child, request == PTRACE_KILL ||
1138 request == PTRACE_INTERRUPT);
1140 goto out_put_task_struct;
1142 ret = arch_ptrace(child, request, addr, data);
1143 if (ret || request != PTRACE_DETACH)
1144 ptrace_unfreeze_traced(child);
1146 out_put_task_struct:
1147 put_task_struct(child);
1152 int generic_ptrace_peekdata(struct task_struct *tsk, unsigned long addr,
1158 copied = access_process_vm(tsk, addr, &tmp, sizeof(tmp), 0);
1159 if (copied != sizeof(tmp))
1161 return put_user(tmp, (unsigned long __user *)data);
1164 int generic_ptrace_pokedata(struct task_struct *tsk, unsigned long addr,
1169 copied = access_process_vm(tsk, addr, &data, sizeof(data), 1);
1170 return (copied == sizeof(data)) ? 0 : -EIO;
1173 #if defined CONFIG_COMPAT
1175 int compat_ptrace_request(struct task_struct *child, compat_long_t request,
1176 compat_ulong_t addr, compat_ulong_t data)
1178 compat_ulong_t __user *datap = compat_ptr(data);
1179 compat_ulong_t word;
1184 case PTRACE_PEEKTEXT:
1185 case PTRACE_PEEKDATA:
1186 ret = access_process_vm(child, addr, &word, sizeof(word), 0);
1187 if (ret != sizeof(word))
1190 ret = put_user(word, datap);
1193 case PTRACE_POKETEXT:
1194 case PTRACE_POKEDATA:
1195 ret = access_process_vm(child, addr, &data, sizeof(data), 1);
1196 ret = (ret != sizeof(data) ? -EIO : 0);
1199 case PTRACE_GETEVENTMSG:
1200 ret = put_user((compat_ulong_t) child->ptrace_message, datap);
1203 case PTRACE_GETSIGINFO:
1204 ret = ptrace_getsiginfo(child, &siginfo);
1206 ret = copy_siginfo_to_user32(
1207 (struct compat_siginfo __user *) datap,
1211 case PTRACE_SETSIGINFO:
1212 memset(&siginfo, 0, sizeof siginfo);
1213 if (copy_siginfo_from_user32(
1214 &siginfo, (struct compat_siginfo __user *) datap))
1217 ret = ptrace_setsiginfo(child, &siginfo);
1219 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
1220 case PTRACE_GETREGSET:
1221 case PTRACE_SETREGSET:
1224 struct compat_iovec __user *uiov =
1225 (struct compat_iovec __user *) datap;
1229 if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov)))
1232 if (__get_user(ptr, &uiov->iov_base) ||
1233 __get_user(len, &uiov->iov_len))
1236 kiov.iov_base = compat_ptr(ptr);
1239 ret = ptrace_regset(child, request, addr, &kiov);
1241 ret = __put_user(kiov.iov_len, &uiov->iov_len);
1247 ret = ptrace_request(child, request, addr, data);
1253 COMPAT_SYSCALL_DEFINE4(ptrace, compat_long_t, request, compat_long_t, pid,
1254 compat_long_t, addr, compat_long_t, data)
1256 struct task_struct *child;
1259 if (request == PTRACE_TRACEME) {
1260 ret = ptrace_traceme();
1264 child = ptrace_get_task_struct(pid);
1265 if (IS_ERR(child)) {
1266 ret = PTR_ERR(child);
1270 if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) {
1271 ret = ptrace_attach(child, request, addr, data);
1273 * Some architectures need to do book-keeping after
1277 arch_ptrace_attach(child);
1278 goto out_put_task_struct;
1281 ret = ptrace_check_attach(child, request == PTRACE_KILL ||
1282 request == PTRACE_INTERRUPT);
1284 ret = compat_arch_ptrace(child, request, addr, data);
1285 if (ret || request != PTRACE_DETACH)
1286 ptrace_unfreeze_traced(child);
1289 out_put_task_struct:
1290 put_task_struct(child);
1294 #endif /* CONFIG_COMPAT */