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/audit.h>
21 #include <linux/pid_namespace.h>
22 #include <linux/syscalls.h>
23 #include <linux/uaccess.h>
24 #include <linux/regset.h>
25 #include <linux/hw_breakpoint.h>
26 #include <linux/cn_proc.h>
29 static int ptrace_trapping_sleep_fn(void *flags)
36 * ptrace a task: make the debugger its new parent and
37 * move it to the ptrace list.
39 * Must be called with the tasklist lock write-held.
41 void __ptrace_link(struct task_struct *child, struct task_struct *new_parent)
43 BUG_ON(!list_empty(&child->ptrace_entry));
44 list_add(&child->ptrace_entry, &new_parent->ptraced);
45 child->parent = new_parent;
49 * __ptrace_unlink - unlink ptracee and restore its execution state
50 * @child: ptracee to be unlinked
52 * Remove @child from the ptrace list, move it back to the original parent,
53 * and restore the execution state so that it conforms to the group stop
56 * Unlinking can happen via two paths - explicit PTRACE_DETACH or ptracer
57 * exiting. For PTRACE_DETACH, unless the ptracee has been killed between
58 * ptrace_check_attach() and here, it's guaranteed to be in TASK_TRACED.
59 * If the ptracer is exiting, the ptracee can be in any state.
61 * After detach, the ptracee should be in a state which conforms to the
62 * group stop. If the group is stopped or in the process of stopping, the
63 * ptracee should be put into TASK_STOPPED; otherwise, it should be woken
64 * up from TASK_TRACED.
66 * If the ptracee is in TASK_TRACED and needs to be moved to TASK_STOPPED,
67 * it goes through TRACED -> RUNNING -> STOPPED transition which is similar
68 * to but in the opposite direction of what happens while attaching to a
69 * stopped task. However, in this direction, the intermediate RUNNING
70 * state is not hidden even from the current ptracer and if it immediately
71 * re-attaches and performs a WNOHANG wait(2), it may fail.
74 * write_lock_irq(tasklist_lock)
76 void __ptrace_unlink(struct task_struct *child)
78 BUG_ON(!child->ptrace);
81 child->parent = child->real_parent;
82 list_del_init(&child->ptrace_entry);
84 spin_lock(&child->sighand->siglock);
87 * Clear all pending traps and TRAPPING. TRAPPING should be
88 * cleared regardless of JOBCTL_STOP_PENDING. Do it explicitly.
90 task_clear_jobctl_pending(child, JOBCTL_TRAP_MASK);
91 task_clear_jobctl_trapping(child);
94 * Reinstate JOBCTL_STOP_PENDING if group stop is in effect and
97 if (!(child->flags & PF_EXITING) &&
98 (child->signal->flags & SIGNAL_STOP_STOPPED ||
99 child->signal->group_stop_count)) {
100 child->jobctl |= JOBCTL_STOP_PENDING;
103 * This is only possible if this thread was cloned by the
104 * traced task running in the stopped group, set the signal
105 * for the future reports.
106 * FIXME: we should change ptrace_init_task() to handle this
109 if (!(child->jobctl & JOBCTL_STOP_SIGMASK))
110 child->jobctl |= SIGSTOP;
114 * If transition to TASK_STOPPED is pending or in TASK_TRACED, kick
115 * @child in the butt. Note that @resume should be used iff @child
116 * is in TASK_TRACED; otherwise, we might unduly disrupt
117 * TASK_KILLABLE sleeps.
119 if (child->jobctl & JOBCTL_STOP_PENDING || task_is_traced(child))
120 ptrace_signal_wake_up(child, true);
122 spin_unlock(&child->sighand->siglock);
125 /* Ensure that nothing can wake it up, even SIGKILL */
126 static bool ptrace_freeze_traced(struct task_struct *task)
130 /* Lockless, nobody but us can set this flag */
131 if (task->jobctl & JOBCTL_LISTENING)
134 spin_lock_irq(&task->sighand->siglock);
135 if (task_is_traced(task) && !__fatal_signal_pending(task)) {
136 task->state = __TASK_TRACED;
139 spin_unlock_irq(&task->sighand->siglock);
144 static void ptrace_unfreeze_traced(struct task_struct *task)
146 if (task->state != __TASK_TRACED)
149 WARN_ON(!task->ptrace || task->parent != current);
152 * PTRACE_LISTEN can allow ptrace_trap_notify to wake us up remotely.
153 * Recheck state under the lock to close this race.
155 spin_lock_irq(&task->sighand->siglock);
156 if (task->state == __TASK_TRACED) {
157 if (__fatal_signal_pending(task))
158 wake_up_state(task, __TASK_TRACED);
160 task->state = TASK_TRACED;
162 spin_unlock_irq(&task->sighand->siglock);
166 * ptrace_check_attach - check whether ptracee is ready for ptrace operation
167 * @child: ptracee to check for
168 * @ignore_state: don't check whether @child is currently %TASK_TRACED
170 * Check whether @child is being ptraced by %current and ready for further
171 * ptrace operations. If @ignore_state is %false, @child also should be in
172 * %TASK_TRACED state and on return the child is guaranteed to be traced
173 * and not executing. If @ignore_state is %true, @child can be in any
177 * Grabs and releases tasklist_lock and @child->sighand->siglock.
180 * 0 on success, -ESRCH if %child is not ready.
182 int ptrace_check_attach(struct task_struct *child, bool ignore_state)
187 * We take the read lock around doing both checks to close a
188 * possible race where someone else was tracing our child and
189 * detached between these two checks. After this locked check,
190 * we are sure that this is our traced child and that can only
191 * be changed by us so it's not changing right after this.
193 read_lock(&tasklist_lock);
194 if (child->ptrace && child->parent == current) {
195 WARN_ON(child->state == __TASK_TRACED);
197 * child->sighand can't be NULL, release_task()
198 * does ptrace_unlink() before __exit_signal().
200 if (ignore_state || ptrace_freeze_traced(child))
203 read_unlock(&tasklist_lock);
205 if (!ret && !ignore_state) {
206 if (!wait_task_inactive(child, __TASK_TRACED)) {
208 * This can only happen if may_ptrace_stop() fails and
209 * ptrace_stop() changes ->state back to TASK_RUNNING,
210 * so we should not worry about leaking __TASK_TRACED.
212 WARN_ON(child->state == __TASK_TRACED);
220 int __ptrace_may_access(struct task_struct *task, unsigned int mode)
222 const struct cred *cred = current_cred(), *tcred;
227 if (!(mode & PTRACE_MODE_FSCREDS) == !(mode & PTRACE_MODE_REALCREDS)) {
228 WARN(1, "denying ptrace access check without PTRACE_MODE_*CREDS\n");
232 /* May we inspect the given task?
233 * This check is used both for attaching with ptrace
234 * and for allowing access to sensitive information in /proc.
236 * ptrace_attach denies several cases that /proc allows
237 * because setting up the necessary parent/child relationship
238 * or halting the specified task is impossible.
241 /* Don't let security modules deny introspection */
242 if (same_thread_group(task, current))
245 if (mode & PTRACE_MODE_FSCREDS) {
246 caller_uid = cred->fsuid;
247 caller_gid = cred->fsgid;
250 * Using the euid would make more sense here, but something
251 * in userland might rely on the old behavior, and this
252 * shouldn't be a security problem since
253 * PTRACE_MODE_REALCREDS implies that the caller explicitly
254 * used a syscall that requests access to another process
255 * (and not a filesystem syscall to procfs).
257 caller_uid = cred->uid;
258 caller_gid = cred->gid;
260 tcred = __task_cred(task);
261 if (cred->user->user_ns == tcred->user->user_ns &&
262 (caller_uid == tcred->euid &&
263 caller_uid == tcred->suid &&
264 caller_uid == tcred->uid &&
265 caller_gid == tcred->egid &&
266 caller_gid == tcred->sgid &&
267 caller_gid == tcred->gid))
269 if (ns_capable(tcred->user->user_ns, CAP_SYS_PTRACE))
277 dumpable = get_dumpable(task->mm);
278 if (dumpable != SUID_DUMP_USER &&
279 !task_ns_capable(task, CAP_SYS_PTRACE))
282 return security_ptrace_access_check(task, mode);
285 bool ptrace_may_access(struct task_struct *task, unsigned int mode)
289 err = __ptrace_may_access(task, mode);
294 static int ptrace_attach(struct task_struct *task, long request,
297 bool seize = (request == PTRACE_SEIZE);
301 * SEIZE will enable new ptrace behaviors which will be implemented
302 * gradually. SEIZE_DEVEL is used to prevent applications
303 * expecting full SEIZE behaviors trapping on kernel commits which
304 * are still in the process of implementing them.
306 * Only test programs for new ptrace behaviors being implemented
307 * should set SEIZE_DEVEL. If unset, SEIZE will fail with -EIO.
309 * Once SEIZE behaviors are completely implemented, this flag and
310 * the following test will be removed.
313 if (seize && !(flags & PTRACE_SEIZE_DEVEL))
319 if (unlikely(task->flags & PF_KTHREAD))
321 if (same_thread_group(task, current))
325 * Protect exec's credential calculations against our interference;
326 * interference; SUID, SGID and LSM creds get determined differently
329 retval = -ERESTARTNOINTR;
330 if (mutex_lock_interruptible(&task->signal->cred_guard_mutex))
334 retval = __ptrace_may_access(task, PTRACE_MODE_ATTACH_REALCREDS);
339 write_lock_irq(&tasklist_lock);
341 if (unlikely(task->exit_state))
342 goto unlock_tasklist;
344 goto unlock_tasklist;
346 task->ptrace = PT_PTRACED;
348 task->ptrace |= PT_SEIZED;
349 if (task_ns_capable(task, CAP_SYS_PTRACE))
350 task->ptrace |= PT_PTRACE_CAP;
352 __ptrace_link(task, current);
354 /* SEIZE doesn't trap tracee on attach */
356 send_sig_info(SIGSTOP, SEND_SIG_FORCED, task);
358 spin_lock(&task->sighand->siglock);
361 * If the task is already STOPPED, set JOBCTL_TRAP_STOP and
362 * TRAPPING, and kick it so that it transits to TRACED. TRAPPING
363 * will be cleared if the child completes the transition or any
364 * event which clears the group stop states happens. We'll wait
365 * for the transition to complete before returning from this
368 * This hides STOPPED -> RUNNING -> TRACED transition from the
369 * attaching thread but a different thread in the same group can
370 * still observe the transient RUNNING state. IOW, if another
371 * thread's WNOHANG wait(2) on the stopped tracee races against
372 * ATTACH, the wait(2) may fail due to the transient RUNNING.
374 * The following task_is_stopped() test is safe as both transitions
375 * in and out of STOPPED are protected by siglock.
377 if (task_is_stopped(task) &&
378 task_set_jobctl_pending(task, JOBCTL_TRAP_STOP | JOBCTL_TRAPPING))
379 signal_wake_up_state(task, __TASK_STOPPED);
381 spin_unlock(&task->sighand->siglock);
385 write_unlock_irq(&tasklist_lock);
387 mutex_unlock(&task->signal->cred_guard_mutex);
390 wait_on_bit(&task->jobctl, JOBCTL_TRAPPING_BIT,
391 ptrace_trapping_sleep_fn, TASK_UNINTERRUPTIBLE);
392 proc_ptrace_connector(task, PTRACE_ATTACH);
399 * ptrace_traceme -- helper for PTRACE_TRACEME
401 * Performs checks and sets PT_PTRACED.
402 * Should be used by all ptrace implementations for PTRACE_TRACEME.
404 static int ptrace_traceme(void)
408 write_lock_irq(&tasklist_lock);
409 /* Are we already being traced? */
410 if (!current->ptrace) {
411 ret = security_ptrace_traceme(current->parent);
413 * Check PF_EXITING to ensure ->real_parent has not passed
414 * exit_ptrace(). Otherwise we don't report the error but
415 * pretend ->real_parent untraces us right after return.
417 if (!ret && !(current->real_parent->flags & PF_EXITING)) {
418 current->ptrace = PT_PTRACED;
419 __ptrace_link(current, current->real_parent);
422 write_unlock_irq(&tasklist_lock);
428 * Called with irqs disabled, returns true if childs should reap themselves.
430 static int ignoring_children(struct sighand_struct *sigh)
433 spin_lock(&sigh->siglock);
434 ret = (sigh->action[SIGCHLD-1].sa.sa_handler == SIG_IGN) ||
435 (sigh->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT);
436 spin_unlock(&sigh->siglock);
441 * Called with tasklist_lock held for writing.
442 * Unlink a traced task, and clean it up if it was a traced zombie.
443 * Return true if it needs to be reaped with release_task().
444 * (We can't call release_task() here because we already hold tasklist_lock.)
446 * If it's a zombie, our attachedness prevented normal parent notification
447 * or self-reaping. Do notification now if it would have happened earlier.
448 * If it should reap itself, return true.
450 * If it's our own child, there is no notification to do. But if our normal
451 * children self-reap, then this child was prevented by ptrace and we must
452 * reap it now, in that case we must also wake up sub-threads sleeping in
455 static bool __ptrace_detach(struct task_struct *tracer, struct task_struct *p)
461 if (p->exit_state != EXIT_ZOMBIE)
464 dead = !thread_group_leader(p);
466 if (!dead && thread_group_empty(p)) {
467 if (!same_thread_group(p->real_parent, tracer))
468 dead = do_notify_parent(p, p->exit_signal);
469 else if (ignoring_children(tracer->sighand)) {
470 __wake_up_parent(p, tracer);
474 /* Mark it as in the process of being reaped. */
476 p->exit_state = EXIT_DEAD;
480 static int ptrace_detach(struct task_struct *child, unsigned int data)
484 if (!valid_signal(data))
487 /* Architecture-specific hardware disable .. */
488 ptrace_disable(child);
489 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
491 write_lock_irq(&tasklist_lock);
493 * This child can be already killed. Make sure de_thread() or
494 * our sub-thread doing do_wait() didn't do release_task() yet.
497 child->exit_code = data;
498 dead = __ptrace_detach(current, child);
500 write_unlock_irq(&tasklist_lock);
502 proc_ptrace_connector(child, PTRACE_DETACH);
510 * Detach all tasks we were using ptrace on. Called with tasklist held
511 * for writing, and returns with it held too. But note it can release
512 * and reacquire the lock.
514 void exit_ptrace(struct task_struct *tracer)
515 __releases(&tasklist_lock)
516 __acquires(&tasklist_lock)
518 struct task_struct *p, *n;
519 LIST_HEAD(ptrace_dead);
521 if (likely(list_empty(&tracer->ptraced)))
524 list_for_each_entry_safe(p, n, &tracer->ptraced, ptrace_entry) {
525 if (__ptrace_detach(tracer, p))
526 list_add(&p->ptrace_entry, &ptrace_dead);
529 write_unlock_irq(&tasklist_lock);
530 BUG_ON(!list_empty(&tracer->ptraced));
532 list_for_each_entry_safe(p, n, &ptrace_dead, ptrace_entry) {
533 list_del_init(&p->ptrace_entry);
537 write_lock_irq(&tasklist_lock);
540 int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len)
546 int this_len, retval;
548 this_len = (len > sizeof(buf)) ? sizeof(buf) : len;
549 retval = access_process_vm(tsk, src, buf, this_len, 0);
555 if (copy_to_user(dst, buf, retval))
565 int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len)
571 int this_len, retval;
573 this_len = (len > sizeof(buf)) ? sizeof(buf) : len;
574 if (copy_from_user(buf, src, this_len))
576 retval = access_process_vm(tsk, dst, buf, this_len, 1);
590 static int ptrace_setoptions(struct task_struct *child, unsigned long data)
592 child->ptrace &= ~PT_TRACE_MASK;
594 if (data & PTRACE_O_TRACESYSGOOD)
595 child->ptrace |= PT_TRACESYSGOOD;
597 if (data & PTRACE_O_TRACEFORK)
598 child->ptrace |= PT_TRACE_FORK;
600 if (data & PTRACE_O_TRACEVFORK)
601 child->ptrace |= PT_TRACE_VFORK;
603 if (data & PTRACE_O_TRACECLONE)
604 child->ptrace |= PT_TRACE_CLONE;
606 if (data & PTRACE_O_TRACEEXEC)
607 child->ptrace |= PT_TRACE_EXEC;
609 if (data & PTRACE_O_TRACEVFORKDONE)
610 child->ptrace |= PT_TRACE_VFORK_DONE;
612 if (data & PTRACE_O_TRACEEXIT)
613 child->ptrace |= PT_TRACE_EXIT;
615 return (data & ~PTRACE_O_MASK) ? -EINVAL : 0;
618 static int ptrace_getsiginfo(struct task_struct *child, siginfo_t *info)
623 if (lock_task_sighand(child, &flags)) {
625 if (likely(child->last_siginfo != NULL)) {
626 *info = *child->last_siginfo;
629 unlock_task_sighand(child, &flags);
634 static int ptrace_setsiginfo(struct task_struct *child, const siginfo_t *info)
639 if (lock_task_sighand(child, &flags)) {
641 if (likely(child->last_siginfo != NULL)) {
642 *child->last_siginfo = *info;
645 unlock_task_sighand(child, &flags);
651 #ifdef PTRACE_SINGLESTEP
652 #define is_singlestep(request) ((request) == PTRACE_SINGLESTEP)
654 #define is_singlestep(request) 0
657 #ifdef PTRACE_SINGLEBLOCK
658 #define is_singleblock(request) ((request) == PTRACE_SINGLEBLOCK)
660 #define is_singleblock(request) 0
664 #define is_sysemu_singlestep(request) ((request) == PTRACE_SYSEMU_SINGLESTEP)
666 #define is_sysemu_singlestep(request) 0
669 static int ptrace_resume(struct task_struct *child, long request,
674 if (!valid_signal(data))
677 if (request == PTRACE_SYSCALL)
678 set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
680 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
682 #ifdef TIF_SYSCALL_EMU
683 if (request == PTRACE_SYSEMU || request == PTRACE_SYSEMU_SINGLESTEP)
684 set_tsk_thread_flag(child, TIF_SYSCALL_EMU);
686 clear_tsk_thread_flag(child, TIF_SYSCALL_EMU);
689 if (is_singleblock(request)) {
690 if (unlikely(!arch_has_block_step()))
692 user_enable_block_step(child);
693 } else if (is_singlestep(request) || is_sysemu_singlestep(request)) {
694 if (unlikely(!arch_has_single_step()))
696 user_enable_single_step(child);
698 user_disable_single_step(child);
702 * Change ->exit_code and ->state under siglock to avoid the race
703 * with wait_task_stopped() in between; a non-zero ->exit_code will
704 * wrongly look like another report from tracee.
706 * Note that we need siglock even if ->exit_code == data and/or this
707 * status was not reported yet, the new status must not be cleared by
708 * wait_task_stopped() after resume.
710 * If data == 0 we do not care if wait_task_stopped() reports the old
711 * status and clears the code too; this can't race with the tracee, it
712 * takes siglock after resume.
714 need_siglock = data && !thread_group_empty(current);
716 spin_lock_irq(&child->sighand->siglock);
717 child->exit_code = data;
718 wake_up_state(child, __TASK_TRACED);
720 spin_unlock_irq(&child->sighand->siglock);
725 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
727 static const struct user_regset *
728 find_regset(const struct user_regset_view *view, unsigned int type)
730 const struct user_regset *regset;
733 for (n = 0; n < view->n; ++n) {
734 regset = view->regsets + n;
735 if (regset->core_note_type == type)
742 static int ptrace_regset(struct task_struct *task, int req, unsigned int type,
745 const struct user_regset_view *view = task_user_regset_view(task);
746 const struct user_regset *regset = find_regset(view, type);
749 if (!regset || (kiov->iov_len % regset->size) != 0)
752 regset_no = regset - view->regsets;
753 kiov->iov_len = min(kiov->iov_len,
754 (__kernel_size_t) (regset->n * regset->size));
756 if (req == PTRACE_GETREGSET)
757 return copy_regset_to_user(task, view, regset_no, 0,
758 kiov->iov_len, kiov->iov_base);
760 return copy_regset_from_user(task, view, regset_no, 0,
761 kiov->iov_len, kiov->iov_base);
766 int ptrace_request(struct task_struct *child, long request,
767 unsigned long addr, unsigned long data)
769 bool seized = child->ptrace & PT_SEIZED;
771 siginfo_t siginfo, *si;
772 void __user *datavp = (void __user *) data;
773 unsigned long __user *datalp = datavp;
777 case PTRACE_PEEKTEXT:
778 case PTRACE_PEEKDATA:
779 return generic_ptrace_peekdata(child, addr, data);
780 case PTRACE_POKETEXT:
781 case PTRACE_POKEDATA:
782 return generic_ptrace_pokedata(child, addr, data);
784 #ifdef PTRACE_OLDSETOPTIONS
785 case PTRACE_OLDSETOPTIONS:
787 case PTRACE_SETOPTIONS:
788 ret = ptrace_setoptions(child, data);
790 case PTRACE_GETEVENTMSG:
791 ret = put_user(child->ptrace_message, datalp);
794 case PTRACE_GETSIGINFO:
795 ret = ptrace_getsiginfo(child, &siginfo);
797 ret = copy_siginfo_to_user(datavp, &siginfo);
800 case PTRACE_SETSIGINFO:
801 if (copy_from_user(&siginfo, datavp, sizeof siginfo))
804 ret = ptrace_setsiginfo(child, &siginfo);
807 case PTRACE_INTERRUPT:
809 * Stop tracee without any side-effect on signal or job
810 * control. At least one trap is guaranteed to happen
811 * after this request. If @child is already trapped, the
812 * current trap is not disturbed and another trap will
813 * happen after the current trap is ended with PTRACE_CONT.
815 * The actual trap might not be PTRACE_EVENT_STOP trap but
816 * the pending condition is cleared regardless.
818 if (unlikely(!seized || !lock_task_sighand(child, &flags)))
822 * INTERRUPT doesn't disturb existing trap sans one
823 * exception. If ptracer issued LISTEN for the current
824 * STOP, this INTERRUPT should clear LISTEN and re-trap
827 if (likely(task_set_jobctl_pending(child, JOBCTL_TRAP_STOP)))
828 ptrace_signal_wake_up(child, child->jobctl & JOBCTL_LISTENING);
830 unlock_task_sighand(child, &flags);
836 * Listen for events. Tracee must be in STOP. It's not
837 * resumed per-se but is not considered to be in TRACED by
838 * wait(2) or ptrace(2). If an async event (e.g. group
839 * stop state change) happens, tracee will enter STOP trap
840 * again. Alternatively, ptracer can issue INTERRUPT to
841 * finish listening and re-trap tracee into STOP.
843 if (unlikely(!seized || !lock_task_sighand(child, &flags)))
846 si = child->last_siginfo;
847 if (likely(si && (si->si_code >> 8) == PTRACE_EVENT_STOP)) {
848 child->jobctl |= JOBCTL_LISTENING;
850 * If NOTIFY is set, it means event happened between
851 * start of this trap and now. Trigger re-trap.
853 if (child->jobctl & JOBCTL_TRAP_NOTIFY)
854 ptrace_signal_wake_up(child, true);
857 unlock_task_sighand(child, &flags);
860 case PTRACE_DETACH: /* detach a process that was attached. */
861 ret = ptrace_detach(child, data);
864 #ifdef CONFIG_BINFMT_ELF_FDPIC
865 case PTRACE_GETFDPIC: {
866 struct mm_struct *mm = get_task_mm(child);
867 unsigned long tmp = 0;
874 case PTRACE_GETFDPIC_EXEC:
875 tmp = mm->context.exec_fdpic_loadmap;
877 case PTRACE_GETFDPIC_INTERP:
878 tmp = mm->context.interp_fdpic_loadmap;
885 ret = put_user(tmp, datalp);
890 #ifdef PTRACE_SINGLESTEP
891 case PTRACE_SINGLESTEP:
893 #ifdef PTRACE_SINGLEBLOCK
894 case PTRACE_SINGLEBLOCK:
898 case PTRACE_SYSEMU_SINGLESTEP:
902 return ptrace_resume(child, request, data);
905 if (child->exit_state) /* already dead */
907 return ptrace_resume(child, request, SIGKILL);
909 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
910 case PTRACE_GETREGSET:
911 case PTRACE_SETREGSET:
914 struct iovec __user *uiov = datavp;
916 if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov)))
919 if (__get_user(kiov.iov_base, &uiov->iov_base) ||
920 __get_user(kiov.iov_len, &uiov->iov_len))
923 ret = ptrace_regset(child, request, addr, &kiov);
925 ret = __put_user(kiov.iov_len, &uiov->iov_len);
936 static struct task_struct *ptrace_get_task_struct(pid_t pid)
938 struct task_struct *child;
941 child = find_task_by_vpid(pid);
943 get_task_struct(child);
947 return ERR_PTR(-ESRCH);
951 #ifndef arch_ptrace_attach
952 #define arch_ptrace_attach(child) do { } while (0)
955 SYSCALL_DEFINE4(ptrace, long, request, long, pid, unsigned long, addr,
958 struct task_struct *child;
961 if (request == PTRACE_TRACEME) {
962 ret = ptrace_traceme();
964 arch_ptrace_attach(current);
968 child = ptrace_get_task_struct(pid);
970 ret = PTR_ERR(child);
974 if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) {
975 ret = ptrace_attach(child, request, data);
977 * Some architectures need to do book-keeping after
981 arch_ptrace_attach(child);
982 goto out_put_task_struct;
985 ret = ptrace_check_attach(child, request == PTRACE_KILL ||
986 request == PTRACE_INTERRUPT);
988 goto out_put_task_struct;
990 ret = arch_ptrace(child, request, addr, data);
991 if (ret || request != PTRACE_DETACH)
992 ptrace_unfreeze_traced(child);
995 put_task_struct(child);
1000 int generic_ptrace_peekdata(struct task_struct *tsk, unsigned long addr,
1006 copied = access_process_vm(tsk, addr, &tmp, sizeof(tmp), 0);
1007 if (copied != sizeof(tmp))
1009 return put_user(tmp, (unsigned long __user *)data);
1012 int generic_ptrace_pokedata(struct task_struct *tsk, unsigned long addr,
1017 copied = access_process_vm(tsk, addr, &data, sizeof(data), 1);
1018 return (copied == sizeof(data)) ? 0 : -EIO;
1021 #if defined CONFIG_COMPAT
1022 #include <linux/compat.h>
1024 int compat_ptrace_request(struct task_struct *child, compat_long_t request,
1025 compat_ulong_t addr, compat_ulong_t data)
1027 compat_ulong_t __user *datap = compat_ptr(data);
1028 compat_ulong_t word;
1033 case PTRACE_PEEKTEXT:
1034 case PTRACE_PEEKDATA:
1035 ret = access_process_vm(child, addr, &word, sizeof(word), 0);
1036 if (ret != sizeof(word))
1039 ret = put_user(word, datap);
1042 case PTRACE_POKETEXT:
1043 case PTRACE_POKEDATA:
1044 ret = access_process_vm(child, addr, &data, sizeof(data), 1);
1045 ret = (ret != sizeof(data) ? -EIO : 0);
1048 case PTRACE_GETEVENTMSG:
1049 ret = put_user((compat_ulong_t) child->ptrace_message, datap);
1052 case PTRACE_GETSIGINFO:
1053 ret = ptrace_getsiginfo(child, &siginfo);
1055 ret = copy_siginfo_to_user32(
1056 (struct compat_siginfo __user *) datap,
1060 case PTRACE_SETSIGINFO:
1061 memset(&siginfo, 0, sizeof siginfo);
1062 if (copy_siginfo_from_user32(
1063 &siginfo, (struct compat_siginfo __user *) datap))
1066 ret = ptrace_setsiginfo(child, &siginfo);
1068 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
1069 case PTRACE_GETREGSET:
1070 case PTRACE_SETREGSET:
1073 struct compat_iovec __user *uiov =
1074 (struct compat_iovec __user *) datap;
1078 if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov)))
1081 if (__get_user(ptr, &uiov->iov_base) ||
1082 __get_user(len, &uiov->iov_len))
1085 kiov.iov_base = compat_ptr(ptr);
1088 ret = ptrace_regset(child, request, addr, &kiov);
1090 ret = __put_user(kiov.iov_len, &uiov->iov_len);
1096 ret = ptrace_request(child, request, addr, data);
1102 asmlinkage long compat_sys_ptrace(compat_long_t request, compat_long_t pid,
1103 compat_long_t addr, compat_long_t data)
1105 struct task_struct *child;
1108 if (request == PTRACE_TRACEME) {
1109 ret = ptrace_traceme();
1113 child = ptrace_get_task_struct(pid);
1114 if (IS_ERR(child)) {
1115 ret = PTR_ERR(child);
1119 if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) {
1120 ret = ptrace_attach(child, request, data);
1122 * Some architectures need to do book-keeping after
1126 arch_ptrace_attach(child);
1127 goto out_put_task_struct;
1130 ret = ptrace_check_attach(child, request == PTRACE_KILL ||
1131 request == PTRACE_INTERRUPT);
1133 ret = compat_arch_ptrace(child, request, addr, data);
1134 if (ret || request != PTRACE_DETACH)
1135 ptrace_unfreeze_traced(child);
1138 out_put_task_struct:
1139 put_task_struct(child);
1143 #endif /* CONFIG_COMPAT */
1145 #ifdef CONFIG_HAVE_HW_BREAKPOINT
1146 int ptrace_get_breakpoints(struct task_struct *tsk)
1148 if (atomic_inc_not_zero(&tsk->ptrace_bp_refcnt))
1154 void ptrace_put_breakpoints(struct task_struct *tsk)
1156 if (atomic_dec_and_test(&tsk->ptrace_bp_refcnt))
1157 flush_ptrace_hw_breakpoint(tsk);
1159 #endif /* CONFIG_HAVE_HW_BREAKPOINT */