2 * linux/kernel/ptrace.c
4 * (C) Copyright 1999 Linus Torvalds
6 * Common interfaces for "ptrace()" which we do not want
7 * to continually duplicate across every architecture.
10 #include <linux/capability.h>
11 #include <linux/export.h>
12 #include <linux/sched.h>
13 #include <linux/errno.h>
15 #include <linux/highmem.h>
16 #include <linux/pagemap.h>
17 #include <linux/ptrace.h>
18 #include <linux/security.h>
19 #include <linux/signal.h>
20 #include <linux/uio.h>
21 #include <linux/audit.h>
22 #include <linux/pid_namespace.h>
23 #include <linux/syscalls.h>
24 #include <linux/uaccess.h>
25 #include <linux/regset.h>
26 #include <linux/hw_breakpoint.h>
27 #include <linux/cn_proc.h>
28 #include <linux/compat.h>
32 * ptrace a task: make the debugger its new parent and
33 * move it to the ptrace list.
35 * Must be called with the tasklist lock write-held.
37 void __ptrace_link(struct task_struct *child, struct task_struct *new_parent)
39 BUG_ON(!list_empty(&child->ptrace_entry));
40 list_add(&child->ptrace_entry, &new_parent->ptraced);
41 child->parent = new_parent;
45 * __ptrace_unlink - unlink ptracee and restore its execution state
46 * @child: ptracee to be unlinked
48 * Remove @child from the ptrace list, move it back to the original parent,
49 * and restore the execution state so that it conforms to the group stop
52 * Unlinking can happen via two paths - explicit PTRACE_DETACH or ptracer
53 * exiting. For PTRACE_DETACH, unless the ptracee has been killed between
54 * ptrace_check_attach() and here, it's guaranteed to be in TASK_TRACED.
55 * If the ptracer is exiting, the ptracee can be in any state.
57 * After detach, the ptracee should be in a state which conforms to the
58 * group stop. If the group is stopped or in the process of stopping, the
59 * ptracee should be put into TASK_STOPPED; otherwise, it should be woken
60 * up from TASK_TRACED.
62 * If the ptracee is in TASK_TRACED and needs to be moved to TASK_STOPPED,
63 * it goes through TRACED -> RUNNING -> STOPPED transition which is similar
64 * to but in the opposite direction of what happens while attaching to a
65 * stopped task. However, in this direction, the intermediate RUNNING
66 * state is not hidden even from the current ptracer and if it immediately
67 * re-attaches and performs a WNOHANG wait(2), it may fail.
70 * write_lock_irq(tasklist_lock)
72 void __ptrace_unlink(struct task_struct *child)
74 BUG_ON(!child->ptrace);
77 child->parent = child->real_parent;
78 list_del_init(&child->ptrace_entry);
80 spin_lock(&child->sighand->siglock);
83 * Clear all pending traps and TRAPPING. TRAPPING should be
84 * cleared regardless of JOBCTL_STOP_PENDING. Do it explicitly.
86 task_clear_jobctl_pending(child, JOBCTL_TRAP_MASK);
87 task_clear_jobctl_trapping(child);
90 * Reinstate JOBCTL_STOP_PENDING if group stop is in effect and
93 if (!(child->flags & PF_EXITING) &&
94 (child->signal->flags & SIGNAL_STOP_STOPPED ||
95 child->signal->group_stop_count)) {
96 child->jobctl |= JOBCTL_STOP_PENDING;
99 * This is only possible if this thread was cloned by the
100 * traced task running in the stopped group, set the signal
101 * for the future reports.
102 * FIXME: we should change ptrace_init_task() to handle this
105 if (!(child->jobctl & JOBCTL_STOP_SIGMASK))
106 child->jobctl |= SIGSTOP;
110 * If transition to TASK_STOPPED is pending or in TASK_TRACED, kick
111 * @child in the butt. Note that @resume should be used iff @child
112 * is in TASK_TRACED; otherwise, we might unduly disrupt
113 * TASK_KILLABLE sleeps.
115 if (child->jobctl & JOBCTL_STOP_PENDING || task_is_traced(child))
116 ptrace_signal_wake_up(child, true);
118 spin_unlock(&child->sighand->siglock);
121 /* Ensure that nothing can wake it up, even SIGKILL */
122 static bool ptrace_freeze_traced(struct task_struct *task)
126 /* Lockless, nobody but us can set this flag */
127 if (task->jobctl & JOBCTL_LISTENING)
130 spin_lock_irq(&task->sighand->siglock);
131 if (task_is_traced(task) && !__fatal_signal_pending(task)) {
132 raw_spin_lock_irq(&task->pi_lock);
133 if (task->state & __TASK_TRACED)
134 task->state = __TASK_TRACED;
136 task->saved_state = __TASK_TRACED;
137 raw_spin_unlock_irq(&task->pi_lock);
140 spin_unlock_irq(&task->sighand->siglock);
145 static void ptrace_unfreeze_traced(struct task_struct *task)
147 if (task->state != __TASK_TRACED)
150 WARN_ON(!task->ptrace || task->parent != current);
152 spin_lock_irq(&task->sighand->siglock);
153 if (__fatal_signal_pending(task))
154 wake_up_state(task, __TASK_TRACED);
156 task->state = TASK_TRACED;
157 spin_unlock_irq(&task->sighand->siglock);
161 * ptrace_check_attach - check whether ptracee is ready for ptrace operation
162 * @child: ptracee to check for
163 * @ignore_state: don't check whether @child is currently %TASK_TRACED
165 * Check whether @child is being ptraced by %current and ready for further
166 * ptrace operations. If @ignore_state is %false, @child also should be in
167 * %TASK_TRACED state and on return the child is guaranteed to be traced
168 * and not executing. If @ignore_state is %true, @child can be in any
172 * Grabs and releases tasklist_lock and @child->sighand->siglock.
175 * 0 on success, -ESRCH if %child is not ready.
177 static int ptrace_check_attach(struct task_struct *child, bool ignore_state)
182 * We take the read lock around doing both checks to close a
183 * possible race where someone else was tracing our child and
184 * detached between these two checks. After this locked check,
185 * we are sure that this is our traced child and that can only
186 * be changed by us so it's not changing right after this.
188 read_lock(&tasklist_lock);
189 if (child->ptrace && child->parent == current) {
190 WARN_ON(child->state == __TASK_TRACED);
192 * child->sighand can't be NULL, release_task()
193 * does ptrace_unlink() before __exit_signal().
195 if (ignore_state || ptrace_freeze_traced(child))
198 read_unlock(&tasklist_lock);
200 if (!ret && !ignore_state) {
201 if (!wait_task_inactive(child, __TASK_TRACED)) {
203 * This can only happen if may_ptrace_stop() fails and
204 * ptrace_stop() changes ->state back to TASK_RUNNING,
205 * so we should not worry about leaking __TASK_TRACED.
207 WARN_ON(child->state == __TASK_TRACED);
215 static int ptrace_has_cap(struct user_namespace *ns, unsigned int mode)
217 if (mode & PTRACE_MODE_NOAUDIT)
218 return has_ns_capability_noaudit(current, ns, CAP_SYS_PTRACE);
220 return has_ns_capability(current, ns, CAP_SYS_PTRACE);
223 /* Returns 0 on success, -errno on denial. */
224 static int __ptrace_may_access(struct task_struct *task, unsigned int mode)
226 const struct cred *cred = current_cred(), *tcred;
228 /* May we inspect the given task?
229 * This check is used both for attaching with ptrace
230 * and for allowing access to sensitive information in /proc.
232 * ptrace_attach denies several cases that /proc allows
233 * because setting up the necessary parent/child relationship
234 * or halting the specified task is impossible.
237 /* Don't let security modules deny introspection */
238 if (same_thread_group(task, current))
241 tcred = __task_cred(task);
242 if (uid_eq(cred->uid, tcred->euid) &&
243 uid_eq(cred->uid, tcred->suid) &&
244 uid_eq(cred->uid, tcred->uid) &&
245 gid_eq(cred->gid, tcred->egid) &&
246 gid_eq(cred->gid, tcred->sgid) &&
247 gid_eq(cred->gid, tcred->gid))
249 if (ptrace_has_cap(tcred->user_ns, mode))
257 dumpable = get_dumpable(task->mm);
259 if (dumpable != SUID_DUMP_USER &&
260 !ptrace_has_cap(__task_cred(task)->user_ns, mode)) {
266 return security_ptrace_access_check(task, mode);
269 bool ptrace_may_access(struct task_struct *task, unsigned int mode)
273 err = __ptrace_may_access(task, mode);
278 static int ptrace_attach(struct task_struct *task, long request,
282 bool seize = (request == PTRACE_SEIZE);
289 if (flags & ~(unsigned long)PTRACE_O_MASK)
291 flags = PT_PTRACED | PT_SEIZED | (flags << PT_OPT_FLAG_SHIFT);
299 if (unlikely(task->flags & PF_KTHREAD))
301 if (same_thread_group(task, current))
305 * Protect exec's credential calculations against our interference;
306 * SUID, SGID and LSM creds get determined differently
309 retval = -ERESTARTNOINTR;
310 if (mutex_lock_interruptible(&task->signal->cred_guard_mutex))
314 retval = __ptrace_may_access(task, PTRACE_MODE_ATTACH);
319 write_lock_irq(&tasklist_lock);
321 if (unlikely(task->exit_state))
322 goto unlock_tasklist;
324 goto unlock_tasklist;
329 if (ns_capable(__task_cred(task)->user_ns, CAP_SYS_PTRACE))
330 flags |= PT_PTRACE_CAP;
332 task->ptrace = flags;
334 __ptrace_link(task, current);
336 /* SEIZE doesn't trap tracee on attach */
338 send_sig_info(SIGSTOP, SEND_SIG_FORCED, task);
340 spin_lock(&task->sighand->siglock);
343 * If the task is already STOPPED, set JOBCTL_TRAP_STOP and
344 * TRAPPING, and kick it so that it transits to TRACED. TRAPPING
345 * will be cleared if the child completes the transition or any
346 * event which clears the group stop states happens. We'll wait
347 * for the transition to complete before returning from this
350 * This hides STOPPED -> RUNNING -> TRACED transition from the
351 * attaching thread but a different thread in the same group can
352 * still observe the transient RUNNING state. IOW, if another
353 * thread's WNOHANG wait(2) on the stopped tracee races against
354 * ATTACH, the wait(2) may fail due to the transient RUNNING.
356 * The following task_is_stopped() test is safe as both transitions
357 * in and out of STOPPED are protected by siglock.
359 if (task_is_stopped(task) &&
360 task_set_jobctl_pending(task, JOBCTL_TRAP_STOP | JOBCTL_TRAPPING))
361 signal_wake_up_state(task, __TASK_STOPPED);
363 spin_unlock(&task->sighand->siglock);
367 write_unlock_irq(&tasklist_lock);
369 mutex_unlock(&task->signal->cred_guard_mutex);
372 wait_on_bit(&task->jobctl, JOBCTL_TRAPPING_BIT,
373 TASK_UNINTERRUPTIBLE);
374 proc_ptrace_connector(task, PTRACE_ATTACH);
381 * ptrace_traceme -- helper for PTRACE_TRACEME
383 * Performs checks and sets PT_PTRACED.
384 * Should be used by all ptrace implementations for PTRACE_TRACEME.
386 static int ptrace_traceme(void)
390 write_lock_irq(&tasklist_lock);
391 /* Are we already being traced? */
392 if (!current->ptrace) {
393 ret = security_ptrace_traceme(current->parent);
395 * Check PF_EXITING to ensure ->real_parent has not passed
396 * exit_ptrace(). Otherwise we don't report the error but
397 * pretend ->real_parent untraces us right after return.
399 if (!ret && !(current->real_parent->flags & PF_EXITING)) {
400 current->ptrace = PT_PTRACED;
401 __ptrace_link(current, current->real_parent);
404 write_unlock_irq(&tasklist_lock);
410 * Called with irqs disabled, returns true if childs should reap themselves.
412 static int ignoring_children(struct sighand_struct *sigh)
415 spin_lock(&sigh->siglock);
416 ret = (sigh->action[SIGCHLD-1].sa.sa_handler == SIG_IGN) ||
417 (sigh->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT);
418 spin_unlock(&sigh->siglock);
423 * Called with tasklist_lock held for writing.
424 * Unlink a traced task, and clean it up if it was a traced zombie.
425 * Return true if it needs to be reaped with release_task().
426 * (We can't call release_task() here because we already hold tasklist_lock.)
428 * If it's a zombie, our attachedness prevented normal parent notification
429 * or self-reaping. Do notification now if it would have happened earlier.
430 * If it should reap itself, return true.
432 * If it's our own child, there is no notification to do. But if our normal
433 * children self-reap, then this child was prevented by ptrace and we must
434 * reap it now, in that case we must also wake up sub-threads sleeping in
437 static bool __ptrace_detach(struct task_struct *tracer, struct task_struct *p)
443 if (p->exit_state != EXIT_ZOMBIE)
446 dead = !thread_group_leader(p);
448 if (!dead && thread_group_empty(p)) {
449 if (!same_thread_group(p->real_parent, tracer))
450 dead = do_notify_parent(p, p->exit_signal);
451 else if (ignoring_children(tracer->sighand)) {
452 __wake_up_parent(p, tracer);
456 /* Mark it as in the process of being reaped. */
458 p->exit_state = EXIT_DEAD;
462 static int ptrace_detach(struct task_struct *child, unsigned int data)
464 if (!valid_signal(data))
467 /* Architecture-specific hardware disable .. */
468 ptrace_disable(child);
469 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
471 write_lock_irq(&tasklist_lock);
473 * We rely on ptrace_freeze_traced(). It can't be killed and
474 * untraced by another thread, it can't be a zombie.
476 WARN_ON(!child->ptrace || child->exit_state);
478 * tasklist_lock avoids the race with wait_task_stopped(), see
479 * the comment in ptrace_resume().
481 child->exit_code = data;
482 __ptrace_detach(current, child);
483 write_unlock_irq(&tasklist_lock);
485 proc_ptrace_connector(child, PTRACE_DETACH);
491 * Detach all tasks we were using ptrace on. Called with tasklist held
494 void exit_ptrace(struct task_struct *tracer, struct list_head *dead)
496 struct task_struct *p, *n;
498 list_for_each_entry_safe(p, n, &tracer->ptraced, ptrace_entry) {
499 if (unlikely(p->ptrace & PT_EXITKILL))
500 send_sig_info(SIGKILL, SEND_SIG_FORCED, p);
502 if (__ptrace_detach(tracer, p))
503 list_add(&p->ptrace_entry, dead);
507 int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len)
513 int this_len, retval;
515 this_len = (len > sizeof(buf)) ? sizeof(buf) : len;
516 retval = access_process_vm(tsk, src, buf, this_len, 0);
522 if (copy_to_user(dst, buf, retval))
532 int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len)
538 int this_len, retval;
540 this_len = (len > sizeof(buf)) ? sizeof(buf) : len;
541 if (copy_from_user(buf, src, this_len))
543 retval = access_process_vm(tsk, dst, buf, this_len, 1);
557 static int ptrace_setoptions(struct task_struct *child, unsigned long data)
561 if (data & ~(unsigned long)PTRACE_O_MASK)
564 /* Avoid intermediate state when all opts are cleared */
565 flags = child->ptrace;
566 flags &= ~(PTRACE_O_MASK << PT_OPT_FLAG_SHIFT);
567 flags |= (data << PT_OPT_FLAG_SHIFT);
568 child->ptrace = flags;
573 static int ptrace_getsiginfo(struct task_struct *child, siginfo_t *info)
578 if (lock_task_sighand(child, &flags)) {
580 if (likely(child->last_siginfo != NULL)) {
581 *info = *child->last_siginfo;
584 unlock_task_sighand(child, &flags);
589 static int ptrace_setsiginfo(struct task_struct *child, const siginfo_t *info)
594 if (lock_task_sighand(child, &flags)) {
596 if (likely(child->last_siginfo != NULL)) {
597 *child->last_siginfo = *info;
600 unlock_task_sighand(child, &flags);
605 static int ptrace_peek_siginfo(struct task_struct *child,
609 struct ptrace_peeksiginfo_args arg;
610 struct sigpending *pending;
614 ret = copy_from_user(&arg, (void __user *) addr,
615 sizeof(struct ptrace_peeksiginfo_args));
619 if (arg.flags & ~PTRACE_PEEKSIGINFO_SHARED)
620 return -EINVAL; /* unknown flags */
625 if (arg.flags & PTRACE_PEEKSIGINFO_SHARED)
626 pending = &child->signal->shared_pending;
628 pending = &child->pending;
630 for (i = 0; i < arg.nr; ) {
632 s32 off = arg.off + i;
634 spin_lock_irq(&child->sighand->siglock);
635 list_for_each_entry(q, &pending->list, list) {
637 copy_siginfo(&info, &q->info);
641 spin_unlock_irq(&child->sighand->siglock);
643 if (off >= 0) /* beyond the end of the list */
647 if (unlikely(is_compat_task())) {
648 compat_siginfo_t __user *uinfo = compat_ptr(data);
650 if (copy_siginfo_to_user32(uinfo, &info) ||
651 __put_user(info.si_code, &uinfo->si_code)) {
659 siginfo_t __user *uinfo = (siginfo_t __user *) data;
661 if (copy_siginfo_to_user(uinfo, &info) ||
662 __put_user(info.si_code, &uinfo->si_code)) {
668 data += sizeof(siginfo_t);
671 if (signal_pending(current))
683 #ifdef PTRACE_SINGLESTEP
684 #define is_singlestep(request) ((request) == PTRACE_SINGLESTEP)
686 #define is_singlestep(request) 0
689 #ifdef PTRACE_SINGLEBLOCK
690 #define is_singleblock(request) ((request) == PTRACE_SINGLEBLOCK)
692 #define is_singleblock(request) 0
696 #define is_sysemu_singlestep(request) ((request) == PTRACE_SYSEMU_SINGLESTEP)
698 #define is_sysemu_singlestep(request) 0
701 static int ptrace_resume(struct task_struct *child, long request,
706 if (!valid_signal(data))
709 if (request == PTRACE_SYSCALL)
710 set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
712 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
714 #ifdef TIF_SYSCALL_EMU
715 if (request == PTRACE_SYSEMU || request == PTRACE_SYSEMU_SINGLESTEP)
716 set_tsk_thread_flag(child, TIF_SYSCALL_EMU);
718 clear_tsk_thread_flag(child, TIF_SYSCALL_EMU);
721 if (is_singleblock(request)) {
722 if (unlikely(!arch_has_block_step()))
724 user_enable_block_step(child);
725 } else if (is_singlestep(request) || is_sysemu_singlestep(request)) {
726 if (unlikely(!arch_has_single_step()))
728 user_enable_single_step(child);
730 user_disable_single_step(child);
734 * Change ->exit_code and ->state under siglock to avoid the race
735 * with wait_task_stopped() in between; a non-zero ->exit_code will
736 * wrongly look like another report from tracee.
738 * Note that we need siglock even if ->exit_code == data and/or this
739 * status was not reported yet, the new status must not be cleared by
740 * wait_task_stopped() after resume.
742 * If data == 0 we do not care if wait_task_stopped() reports the old
743 * status and clears the code too; this can't race with the tracee, it
744 * takes siglock after resume.
746 need_siglock = data && !thread_group_empty(current);
748 spin_lock_irq(&child->sighand->siglock);
749 child->exit_code = data;
750 wake_up_state(child, __TASK_TRACED);
752 spin_unlock_irq(&child->sighand->siglock);
757 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
759 static const struct user_regset *
760 find_regset(const struct user_regset_view *view, unsigned int type)
762 const struct user_regset *regset;
765 for (n = 0; n < view->n; ++n) {
766 regset = view->regsets + n;
767 if (regset->core_note_type == type)
774 static int ptrace_regset(struct task_struct *task, int req, unsigned int type,
777 const struct user_regset_view *view = task_user_regset_view(task);
778 const struct user_regset *regset = find_regset(view, type);
781 if (!regset || (kiov->iov_len % regset->size) != 0)
784 regset_no = regset - view->regsets;
785 kiov->iov_len = min(kiov->iov_len,
786 (__kernel_size_t) (regset->n * regset->size));
788 if (req == PTRACE_GETREGSET)
789 return copy_regset_to_user(task, view, regset_no, 0,
790 kiov->iov_len, kiov->iov_base);
792 return copy_regset_from_user(task, view, regset_no, 0,
793 kiov->iov_len, kiov->iov_base);
797 * This is declared in linux/regset.h and defined in machine-dependent
798 * code. We put the export here, near the primary machine-neutral use,
799 * to ensure no machine forgets it.
801 EXPORT_SYMBOL_GPL(task_user_regset_view);
804 int ptrace_request(struct task_struct *child, long request,
805 unsigned long addr, unsigned long data)
807 bool seized = child->ptrace & PT_SEIZED;
809 siginfo_t siginfo, *si;
810 void __user *datavp = (void __user *) data;
811 unsigned long __user *datalp = datavp;
815 case PTRACE_PEEKTEXT:
816 case PTRACE_PEEKDATA:
817 return generic_ptrace_peekdata(child, addr, data);
818 case PTRACE_POKETEXT:
819 case PTRACE_POKEDATA:
820 return generic_ptrace_pokedata(child, addr, data);
822 #ifdef PTRACE_OLDSETOPTIONS
823 case PTRACE_OLDSETOPTIONS:
825 case PTRACE_SETOPTIONS:
826 ret = ptrace_setoptions(child, data);
828 case PTRACE_GETEVENTMSG:
829 ret = put_user(child->ptrace_message, datalp);
832 case PTRACE_PEEKSIGINFO:
833 ret = ptrace_peek_siginfo(child, addr, data);
836 case PTRACE_GETSIGINFO:
837 ret = ptrace_getsiginfo(child, &siginfo);
839 ret = copy_siginfo_to_user(datavp, &siginfo);
842 case PTRACE_SETSIGINFO:
843 if (copy_from_user(&siginfo, datavp, sizeof siginfo))
846 ret = ptrace_setsiginfo(child, &siginfo);
849 case PTRACE_GETSIGMASK:
850 if (addr != sizeof(sigset_t)) {
855 if (copy_to_user(datavp, &child->blocked, sizeof(sigset_t)))
862 case PTRACE_SETSIGMASK: {
865 if (addr != sizeof(sigset_t)) {
870 if (copy_from_user(&new_set, datavp, sizeof(sigset_t))) {
875 sigdelsetmask(&new_set, sigmask(SIGKILL)|sigmask(SIGSTOP));
878 * Every thread does recalc_sigpending() after resume, so
879 * retarget_shared_pending() and recalc_sigpending() are not
882 spin_lock_irq(&child->sighand->siglock);
883 child->blocked = new_set;
884 spin_unlock_irq(&child->sighand->siglock);
890 case PTRACE_INTERRUPT:
892 * Stop tracee without any side-effect on signal or job
893 * control. At least one trap is guaranteed to happen
894 * after this request. If @child is already trapped, the
895 * current trap is not disturbed and another trap will
896 * happen after the current trap is ended with PTRACE_CONT.
898 * The actual trap might not be PTRACE_EVENT_STOP trap but
899 * the pending condition is cleared regardless.
901 if (unlikely(!seized || !lock_task_sighand(child, &flags)))
905 * INTERRUPT doesn't disturb existing trap sans one
906 * exception. If ptracer issued LISTEN for the current
907 * STOP, this INTERRUPT should clear LISTEN and re-trap
910 if (likely(task_set_jobctl_pending(child, JOBCTL_TRAP_STOP)))
911 ptrace_signal_wake_up(child, child->jobctl & JOBCTL_LISTENING);
913 unlock_task_sighand(child, &flags);
919 * Listen for events. Tracee must be in STOP. It's not
920 * resumed per-se but is not considered to be in TRACED by
921 * wait(2) or ptrace(2). If an async event (e.g. group
922 * stop state change) happens, tracee will enter STOP trap
923 * again. Alternatively, ptracer can issue INTERRUPT to
924 * finish listening and re-trap tracee into STOP.
926 if (unlikely(!seized || !lock_task_sighand(child, &flags)))
929 si = child->last_siginfo;
930 if (likely(si && (si->si_code >> 8) == PTRACE_EVENT_STOP)) {
931 child->jobctl |= JOBCTL_LISTENING;
933 * If NOTIFY is set, it means event happened between
934 * start of this trap and now. Trigger re-trap.
936 if (child->jobctl & JOBCTL_TRAP_NOTIFY)
937 ptrace_signal_wake_up(child, true);
940 unlock_task_sighand(child, &flags);
943 case PTRACE_DETACH: /* detach a process that was attached. */
944 ret = ptrace_detach(child, data);
947 #ifdef CONFIG_BINFMT_ELF_FDPIC
948 case PTRACE_GETFDPIC: {
949 struct mm_struct *mm = get_task_mm(child);
950 unsigned long tmp = 0;
957 case PTRACE_GETFDPIC_EXEC:
958 tmp = mm->context.exec_fdpic_loadmap;
960 case PTRACE_GETFDPIC_INTERP:
961 tmp = mm->context.interp_fdpic_loadmap;
968 ret = put_user(tmp, datalp);
973 #ifdef PTRACE_SINGLESTEP
974 case PTRACE_SINGLESTEP:
976 #ifdef PTRACE_SINGLEBLOCK
977 case PTRACE_SINGLEBLOCK:
981 case PTRACE_SYSEMU_SINGLESTEP:
985 return ptrace_resume(child, request, data);
988 if (child->exit_state) /* already dead */
990 return ptrace_resume(child, request, SIGKILL);
992 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
993 case PTRACE_GETREGSET:
994 case PTRACE_SETREGSET: {
996 struct iovec __user *uiov = datavp;
998 if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov)))
1001 if (__get_user(kiov.iov_base, &uiov->iov_base) ||
1002 __get_user(kiov.iov_len, &uiov->iov_len))
1005 ret = ptrace_regset(child, request, addr, &kiov);
1007 ret = __put_user(kiov.iov_len, &uiov->iov_len);
1018 static struct task_struct *ptrace_get_task_struct(pid_t pid)
1020 struct task_struct *child;
1023 child = find_task_by_vpid(pid);
1025 get_task_struct(child);
1029 return ERR_PTR(-ESRCH);
1033 #ifndef arch_ptrace_attach
1034 #define arch_ptrace_attach(child) do { } while (0)
1037 SYSCALL_DEFINE4(ptrace, long, request, long, pid, unsigned long, addr,
1038 unsigned long, data)
1040 struct task_struct *child;
1043 if (request == PTRACE_TRACEME) {
1044 ret = ptrace_traceme();
1046 arch_ptrace_attach(current);
1050 child = ptrace_get_task_struct(pid);
1051 if (IS_ERR(child)) {
1052 ret = PTR_ERR(child);
1056 if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) {
1057 ret = ptrace_attach(child, request, addr, data);
1059 * Some architectures need to do book-keeping after
1063 arch_ptrace_attach(child);
1064 goto out_put_task_struct;
1067 ret = ptrace_check_attach(child, request == PTRACE_KILL ||
1068 request == PTRACE_INTERRUPT);
1070 goto out_put_task_struct;
1072 ret = arch_ptrace(child, request, addr, data);
1073 if (ret || request != PTRACE_DETACH)
1074 ptrace_unfreeze_traced(child);
1076 out_put_task_struct:
1077 put_task_struct(child);
1082 int generic_ptrace_peekdata(struct task_struct *tsk, unsigned long addr,
1088 copied = access_process_vm(tsk, addr, &tmp, sizeof(tmp), 0);
1089 if (copied != sizeof(tmp))
1091 return put_user(tmp, (unsigned long __user *)data);
1094 int generic_ptrace_pokedata(struct task_struct *tsk, unsigned long addr,
1099 copied = access_process_vm(tsk, addr, &data, sizeof(data), 1);
1100 return (copied == sizeof(data)) ? 0 : -EIO;
1103 #if defined CONFIG_COMPAT
1105 int compat_ptrace_request(struct task_struct *child, compat_long_t request,
1106 compat_ulong_t addr, compat_ulong_t data)
1108 compat_ulong_t __user *datap = compat_ptr(data);
1109 compat_ulong_t word;
1114 case PTRACE_PEEKTEXT:
1115 case PTRACE_PEEKDATA:
1116 ret = access_process_vm(child, addr, &word, sizeof(word), 0);
1117 if (ret != sizeof(word))
1120 ret = put_user(word, datap);
1123 case PTRACE_POKETEXT:
1124 case PTRACE_POKEDATA:
1125 ret = access_process_vm(child, addr, &data, sizeof(data), 1);
1126 ret = (ret != sizeof(data) ? -EIO : 0);
1129 case PTRACE_GETEVENTMSG:
1130 ret = put_user((compat_ulong_t) child->ptrace_message, datap);
1133 case PTRACE_GETSIGINFO:
1134 ret = ptrace_getsiginfo(child, &siginfo);
1136 ret = copy_siginfo_to_user32(
1137 (struct compat_siginfo __user *) datap,
1141 case PTRACE_SETSIGINFO:
1142 memset(&siginfo, 0, sizeof siginfo);
1143 if (copy_siginfo_from_user32(
1144 &siginfo, (struct compat_siginfo __user *) datap))
1147 ret = ptrace_setsiginfo(child, &siginfo);
1149 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
1150 case PTRACE_GETREGSET:
1151 case PTRACE_SETREGSET:
1154 struct compat_iovec __user *uiov =
1155 (struct compat_iovec __user *) datap;
1159 if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov)))
1162 if (__get_user(ptr, &uiov->iov_base) ||
1163 __get_user(len, &uiov->iov_len))
1166 kiov.iov_base = compat_ptr(ptr);
1169 ret = ptrace_regset(child, request, addr, &kiov);
1171 ret = __put_user(kiov.iov_len, &uiov->iov_len);
1177 ret = ptrace_request(child, request, addr, data);
1183 COMPAT_SYSCALL_DEFINE4(ptrace, compat_long_t, request, compat_long_t, pid,
1184 compat_long_t, addr, compat_long_t, data)
1186 struct task_struct *child;
1189 if (request == PTRACE_TRACEME) {
1190 ret = ptrace_traceme();
1194 child = ptrace_get_task_struct(pid);
1195 if (IS_ERR(child)) {
1196 ret = PTR_ERR(child);
1200 if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) {
1201 ret = ptrace_attach(child, request, addr, data);
1203 * Some architectures need to do book-keeping after
1207 arch_ptrace_attach(child);
1208 goto out_put_task_struct;
1211 ret = ptrace_check_attach(child, request == PTRACE_KILL ||
1212 request == PTRACE_INTERRUPT);
1214 ret = compat_arch_ptrace(child, request, addr, data);
1215 if (ret || request != PTRACE_DETACH)
1216 ptrace_unfreeze_traced(child);
1219 out_put_task_struct:
1220 put_task_struct(child);
1224 #endif /* CONFIG_COMPAT */