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 task->state = __TASK_TRACED;
135 spin_unlock_irq(&task->sighand->siglock);
140 static void ptrace_unfreeze_traced(struct task_struct *task)
142 if (task->state != __TASK_TRACED)
145 WARN_ON(!task->ptrace || task->parent != current);
147 spin_lock_irq(&task->sighand->siglock);
148 if (__fatal_signal_pending(task))
149 wake_up_state(task, __TASK_TRACED);
151 task->state = TASK_TRACED;
152 spin_unlock_irq(&task->sighand->siglock);
156 * ptrace_check_attach - check whether ptracee is ready for ptrace operation
157 * @child: ptracee to check for
158 * @ignore_state: don't check whether @child is currently %TASK_TRACED
160 * Check whether @child is being ptraced by %current and ready for further
161 * ptrace operations. If @ignore_state is %false, @child also should be in
162 * %TASK_TRACED state and on return the child is guaranteed to be traced
163 * and not executing. If @ignore_state is %true, @child can be in any
167 * Grabs and releases tasklist_lock and @child->sighand->siglock.
170 * 0 on success, -ESRCH if %child is not ready.
172 static int ptrace_check_attach(struct task_struct *child, bool ignore_state)
177 * We take the read lock around doing both checks to close a
178 * possible race where someone else was tracing our child and
179 * detached between these two checks. After this locked check,
180 * we are sure that this is our traced child and that can only
181 * be changed by us so it's not changing right after this.
183 read_lock(&tasklist_lock);
184 if (child->ptrace && child->parent == current) {
185 WARN_ON(child->state == __TASK_TRACED);
187 * child->sighand can't be NULL, release_task()
188 * does ptrace_unlink() before __exit_signal().
190 if (ignore_state || ptrace_freeze_traced(child))
193 read_unlock(&tasklist_lock);
195 if (!ret && !ignore_state) {
196 if (!wait_task_inactive(child, __TASK_TRACED)) {
198 * This can only happen if may_ptrace_stop() fails and
199 * ptrace_stop() changes ->state back to TASK_RUNNING,
200 * so we should not worry about leaking __TASK_TRACED.
202 WARN_ON(child->state == __TASK_TRACED);
210 static int ptrace_has_cap(struct user_namespace *ns, unsigned int mode)
212 if (mode & PTRACE_MODE_NOAUDIT)
213 return has_ns_capability_noaudit(current, ns, CAP_SYS_PTRACE);
215 return has_ns_capability(current, ns, CAP_SYS_PTRACE);
218 /* Returns 0 on success, -errno on denial. */
219 static int __ptrace_may_access(struct task_struct *task, unsigned int mode)
221 const struct cred *cred = current_cred(), *tcred;
223 /* May we inspect the given task?
224 * This check is used both for attaching with ptrace
225 * and for allowing access to sensitive information in /proc.
227 * ptrace_attach denies several cases that /proc allows
228 * because setting up the necessary parent/child relationship
229 * or halting the specified task is impossible.
232 /* Don't let security modules deny introspection */
233 if (same_thread_group(task, current))
236 tcred = __task_cred(task);
237 if (uid_eq(cred->uid, tcred->euid) &&
238 uid_eq(cred->uid, tcred->suid) &&
239 uid_eq(cred->uid, tcred->uid) &&
240 gid_eq(cred->gid, tcred->egid) &&
241 gid_eq(cred->gid, tcred->sgid) &&
242 gid_eq(cred->gid, tcred->gid))
244 if (ptrace_has_cap(tcred->user_ns, mode))
252 dumpable = get_dumpable(task->mm);
254 if (dumpable != SUID_DUMP_USER &&
255 !ptrace_has_cap(__task_cred(task)->user_ns, mode)) {
261 return security_ptrace_access_check(task, mode);
264 bool ptrace_may_access(struct task_struct *task, unsigned int mode)
268 err = __ptrace_may_access(task, mode);
273 static int ptrace_attach(struct task_struct *task, long request,
277 bool seize = (request == PTRACE_SEIZE);
284 if (flags & ~(unsigned long)PTRACE_O_MASK)
286 flags = PT_PTRACED | PT_SEIZED | (flags << PT_OPT_FLAG_SHIFT);
294 if (unlikely(task->flags & PF_KTHREAD))
296 if (same_thread_group(task, current))
300 * Protect exec's credential calculations against our interference;
301 * SUID, SGID and LSM creds get determined differently
304 retval = -ERESTARTNOINTR;
305 if (mutex_lock_interruptible(&task->signal->cred_guard_mutex))
309 retval = __ptrace_may_access(task, PTRACE_MODE_ATTACH);
314 write_lock_irq(&tasklist_lock);
316 if (unlikely(task->exit_state))
317 goto unlock_tasklist;
319 goto unlock_tasklist;
324 if (ns_capable(__task_cred(task)->user_ns, CAP_SYS_PTRACE))
325 flags |= PT_PTRACE_CAP;
327 task->ptrace = flags;
329 __ptrace_link(task, current);
331 /* SEIZE doesn't trap tracee on attach */
333 send_sig_info(SIGSTOP, SEND_SIG_FORCED, task);
335 spin_lock(&task->sighand->siglock);
338 * If the task is already STOPPED, set JOBCTL_TRAP_STOP and
339 * TRAPPING, and kick it so that it transits to TRACED. TRAPPING
340 * will be cleared if the child completes the transition or any
341 * event which clears the group stop states happens. We'll wait
342 * for the transition to complete before returning from this
345 * This hides STOPPED -> RUNNING -> TRACED transition from the
346 * attaching thread but a different thread in the same group can
347 * still observe the transient RUNNING state. IOW, if another
348 * thread's WNOHANG wait(2) on the stopped tracee races against
349 * ATTACH, the wait(2) may fail due to the transient RUNNING.
351 * The following task_is_stopped() test is safe as both transitions
352 * in and out of STOPPED are protected by siglock.
354 if (task_is_stopped(task) &&
355 task_set_jobctl_pending(task, JOBCTL_TRAP_STOP | JOBCTL_TRAPPING))
356 signal_wake_up_state(task, __TASK_STOPPED);
358 spin_unlock(&task->sighand->siglock);
362 write_unlock_irq(&tasklist_lock);
364 mutex_unlock(&task->signal->cred_guard_mutex);
367 wait_on_bit(&task->jobctl, JOBCTL_TRAPPING_BIT,
368 TASK_UNINTERRUPTIBLE);
369 proc_ptrace_connector(task, PTRACE_ATTACH);
376 * ptrace_traceme -- helper for PTRACE_TRACEME
378 * Performs checks and sets PT_PTRACED.
379 * Should be used by all ptrace implementations for PTRACE_TRACEME.
381 static int ptrace_traceme(void)
385 write_lock_irq(&tasklist_lock);
386 /* Are we already being traced? */
387 if (!current->ptrace) {
388 ret = security_ptrace_traceme(current->parent);
390 * Check PF_EXITING to ensure ->real_parent has not passed
391 * exit_ptrace(). Otherwise we don't report the error but
392 * pretend ->real_parent untraces us right after return.
394 if (!ret && !(current->real_parent->flags & PF_EXITING)) {
395 current->ptrace = PT_PTRACED;
396 __ptrace_link(current, current->real_parent);
399 write_unlock_irq(&tasklist_lock);
405 * Called with irqs disabled, returns true if childs should reap themselves.
407 static int ignoring_children(struct sighand_struct *sigh)
410 spin_lock(&sigh->siglock);
411 ret = (sigh->action[SIGCHLD-1].sa.sa_handler == SIG_IGN) ||
412 (sigh->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT);
413 spin_unlock(&sigh->siglock);
418 * Called with tasklist_lock held for writing.
419 * Unlink a traced task, and clean it up if it was a traced zombie.
420 * Return true if it needs to be reaped with release_task().
421 * (We can't call release_task() here because we already hold tasklist_lock.)
423 * If it's a zombie, our attachedness prevented normal parent notification
424 * or self-reaping. Do notification now if it would have happened earlier.
425 * If it should reap itself, return true.
427 * If it's our own child, there is no notification to do. But if our normal
428 * children self-reap, then this child was prevented by ptrace and we must
429 * reap it now, in that case we must also wake up sub-threads sleeping in
432 static bool __ptrace_detach(struct task_struct *tracer, struct task_struct *p)
438 if (p->exit_state != EXIT_ZOMBIE)
441 dead = !thread_group_leader(p);
443 if (!dead && thread_group_empty(p)) {
444 if (!same_thread_group(p->real_parent, tracer))
445 dead = do_notify_parent(p, p->exit_signal);
446 else if (ignoring_children(tracer->sighand)) {
447 __wake_up_parent(p, tracer);
451 /* Mark it as in the process of being reaped. */
453 p->exit_state = EXIT_DEAD;
457 static int ptrace_detach(struct task_struct *child, unsigned int data)
461 if (!valid_signal(data))
464 /* Architecture-specific hardware disable .. */
465 ptrace_disable(child);
466 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
468 write_lock_irq(&tasklist_lock);
470 * This child can be already killed. Make sure de_thread() or
471 * our sub-thread doing do_wait() didn't do release_task() yet.
474 child->exit_code = data;
475 dead = __ptrace_detach(current, child);
477 write_unlock_irq(&tasklist_lock);
479 proc_ptrace_connector(child, PTRACE_DETACH);
487 * Detach all tasks we were using ptrace on. Called with tasklist held
490 void exit_ptrace(struct task_struct *tracer, struct list_head *dead)
492 struct task_struct *p, *n;
494 list_for_each_entry_safe(p, n, &tracer->ptraced, ptrace_entry) {
495 if (unlikely(p->ptrace & PT_EXITKILL))
496 send_sig_info(SIGKILL, SEND_SIG_FORCED, p);
498 if (__ptrace_detach(tracer, p))
499 list_add(&p->ptrace_entry, dead);
503 int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len)
509 int this_len, retval;
511 this_len = (len > sizeof(buf)) ? sizeof(buf) : len;
512 retval = access_process_vm(tsk, src, buf, this_len, 0);
518 if (copy_to_user(dst, buf, retval))
528 int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len)
534 int this_len, retval;
536 this_len = (len > sizeof(buf)) ? sizeof(buf) : len;
537 if (copy_from_user(buf, src, this_len))
539 retval = access_process_vm(tsk, dst, buf, this_len, 1);
553 static int ptrace_setoptions(struct task_struct *child, unsigned long data)
557 if (data & ~(unsigned long)PTRACE_O_MASK)
560 /* Avoid intermediate state when all opts are cleared */
561 flags = child->ptrace;
562 flags &= ~(PTRACE_O_MASK << PT_OPT_FLAG_SHIFT);
563 flags |= (data << PT_OPT_FLAG_SHIFT);
564 child->ptrace = flags;
569 static int ptrace_getsiginfo(struct task_struct *child, siginfo_t *info)
574 if (lock_task_sighand(child, &flags)) {
576 if (likely(child->last_siginfo != NULL)) {
577 *info = *child->last_siginfo;
580 unlock_task_sighand(child, &flags);
585 static int ptrace_setsiginfo(struct task_struct *child, const siginfo_t *info)
590 if (lock_task_sighand(child, &flags)) {
592 if (likely(child->last_siginfo != NULL)) {
593 *child->last_siginfo = *info;
596 unlock_task_sighand(child, &flags);
601 static int ptrace_peek_siginfo(struct task_struct *child,
605 struct ptrace_peeksiginfo_args arg;
606 struct sigpending *pending;
610 ret = copy_from_user(&arg, (void __user *) addr,
611 sizeof(struct ptrace_peeksiginfo_args));
615 if (arg.flags & ~PTRACE_PEEKSIGINFO_SHARED)
616 return -EINVAL; /* unknown flags */
621 if (arg.flags & PTRACE_PEEKSIGINFO_SHARED)
622 pending = &child->signal->shared_pending;
624 pending = &child->pending;
626 for (i = 0; i < arg.nr; ) {
628 s32 off = arg.off + i;
630 spin_lock_irq(&child->sighand->siglock);
631 list_for_each_entry(q, &pending->list, list) {
633 copy_siginfo(&info, &q->info);
637 spin_unlock_irq(&child->sighand->siglock);
639 if (off >= 0) /* beyond the end of the list */
643 if (unlikely(is_compat_task())) {
644 compat_siginfo_t __user *uinfo = compat_ptr(data);
646 if (copy_siginfo_to_user32(uinfo, &info) ||
647 __put_user(info.si_code, &uinfo->si_code)) {
655 siginfo_t __user *uinfo = (siginfo_t __user *) data;
657 if (copy_siginfo_to_user(uinfo, &info) ||
658 __put_user(info.si_code, &uinfo->si_code)) {
664 data += sizeof(siginfo_t);
667 if (signal_pending(current))
679 #ifdef PTRACE_SINGLESTEP
680 #define is_singlestep(request) ((request) == PTRACE_SINGLESTEP)
682 #define is_singlestep(request) 0
685 #ifdef PTRACE_SINGLEBLOCK
686 #define is_singleblock(request) ((request) == PTRACE_SINGLEBLOCK)
688 #define is_singleblock(request) 0
692 #define is_sysemu_singlestep(request) ((request) == PTRACE_SYSEMU_SINGLESTEP)
694 #define is_sysemu_singlestep(request) 0
697 static int ptrace_resume(struct task_struct *child, long request,
700 if (!valid_signal(data))
703 if (request == PTRACE_SYSCALL)
704 set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
706 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
708 #ifdef TIF_SYSCALL_EMU
709 if (request == PTRACE_SYSEMU || request == PTRACE_SYSEMU_SINGLESTEP)
710 set_tsk_thread_flag(child, TIF_SYSCALL_EMU);
712 clear_tsk_thread_flag(child, TIF_SYSCALL_EMU);
715 if (is_singleblock(request)) {
716 if (unlikely(!arch_has_block_step()))
718 user_enable_block_step(child);
719 } else if (is_singlestep(request) || is_sysemu_singlestep(request)) {
720 if (unlikely(!arch_has_single_step()))
722 user_enable_single_step(child);
724 user_disable_single_step(child);
727 child->exit_code = data;
728 wake_up_state(child, __TASK_TRACED);
733 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
735 static const struct user_regset *
736 find_regset(const struct user_regset_view *view, unsigned int type)
738 const struct user_regset *regset;
741 for (n = 0; n < view->n; ++n) {
742 regset = view->regsets + n;
743 if (regset->core_note_type == type)
750 static int ptrace_regset(struct task_struct *task, int req, unsigned int type,
753 const struct user_regset_view *view = task_user_regset_view(task);
754 const struct user_regset *regset = find_regset(view, type);
757 if (!regset || (kiov->iov_len % regset->size) != 0)
760 regset_no = regset - view->regsets;
761 kiov->iov_len = min(kiov->iov_len,
762 (__kernel_size_t) (regset->n * regset->size));
764 if (req == PTRACE_GETREGSET)
765 return copy_regset_to_user(task, view, regset_no, 0,
766 kiov->iov_len, kiov->iov_base);
768 return copy_regset_from_user(task, view, regset_no, 0,
769 kiov->iov_len, kiov->iov_base);
773 * This is declared in linux/regset.h and defined in machine-dependent
774 * code. We put the export here, near the primary machine-neutral use,
775 * to ensure no machine forgets it.
777 EXPORT_SYMBOL_GPL(task_user_regset_view);
780 int ptrace_request(struct task_struct *child, long request,
781 unsigned long addr, unsigned long data)
783 bool seized = child->ptrace & PT_SEIZED;
785 siginfo_t siginfo, *si;
786 void __user *datavp = (void __user *) data;
787 unsigned long __user *datalp = datavp;
791 case PTRACE_PEEKTEXT:
792 case PTRACE_PEEKDATA:
793 return generic_ptrace_peekdata(child, addr, data);
794 case PTRACE_POKETEXT:
795 case PTRACE_POKEDATA:
796 return generic_ptrace_pokedata(child, addr, data);
798 #ifdef PTRACE_OLDSETOPTIONS
799 case PTRACE_OLDSETOPTIONS:
801 case PTRACE_SETOPTIONS:
802 ret = ptrace_setoptions(child, data);
804 case PTRACE_GETEVENTMSG:
805 ret = put_user(child->ptrace_message, datalp);
808 case PTRACE_PEEKSIGINFO:
809 ret = ptrace_peek_siginfo(child, addr, data);
812 case PTRACE_GETSIGINFO:
813 ret = ptrace_getsiginfo(child, &siginfo);
815 ret = copy_siginfo_to_user(datavp, &siginfo);
818 case PTRACE_SETSIGINFO:
819 if (copy_from_user(&siginfo, datavp, sizeof siginfo))
822 ret = ptrace_setsiginfo(child, &siginfo);
825 case PTRACE_GETSIGMASK:
826 if (addr != sizeof(sigset_t)) {
831 if (copy_to_user(datavp, &child->blocked, sizeof(sigset_t)))
838 case PTRACE_SETSIGMASK: {
841 if (addr != sizeof(sigset_t)) {
846 if (copy_from_user(&new_set, datavp, sizeof(sigset_t))) {
851 sigdelsetmask(&new_set, sigmask(SIGKILL)|sigmask(SIGSTOP));
854 * Every thread does recalc_sigpending() after resume, so
855 * retarget_shared_pending() and recalc_sigpending() are not
858 spin_lock_irq(&child->sighand->siglock);
859 child->blocked = new_set;
860 spin_unlock_irq(&child->sighand->siglock);
866 case PTRACE_INTERRUPT:
868 * Stop tracee without any side-effect on signal or job
869 * control. At least one trap is guaranteed to happen
870 * after this request. If @child is already trapped, the
871 * current trap is not disturbed and another trap will
872 * happen after the current trap is ended with PTRACE_CONT.
874 * The actual trap might not be PTRACE_EVENT_STOP trap but
875 * the pending condition is cleared regardless.
877 if (unlikely(!seized || !lock_task_sighand(child, &flags)))
881 * INTERRUPT doesn't disturb existing trap sans one
882 * exception. If ptracer issued LISTEN for the current
883 * STOP, this INTERRUPT should clear LISTEN and re-trap
886 if (likely(task_set_jobctl_pending(child, JOBCTL_TRAP_STOP)))
887 ptrace_signal_wake_up(child, child->jobctl & JOBCTL_LISTENING);
889 unlock_task_sighand(child, &flags);
895 * Listen for events. Tracee must be in STOP. It's not
896 * resumed per-se but is not considered to be in TRACED by
897 * wait(2) or ptrace(2). If an async event (e.g. group
898 * stop state change) happens, tracee will enter STOP trap
899 * again. Alternatively, ptracer can issue INTERRUPT to
900 * finish listening and re-trap tracee into STOP.
902 if (unlikely(!seized || !lock_task_sighand(child, &flags)))
905 si = child->last_siginfo;
906 if (likely(si && (si->si_code >> 8) == PTRACE_EVENT_STOP)) {
907 child->jobctl |= JOBCTL_LISTENING;
909 * If NOTIFY is set, it means event happened between
910 * start of this trap and now. Trigger re-trap.
912 if (child->jobctl & JOBCTL_TRAP_NOTIFY)
913 ptrace_signal_wake_up(child, true);
916 unlock_task_sighand(child, &flags);
919 case PTRACE_DETACH: /* detach a process that was attached. */
920 ret = ptrace_detach(child, data);
923 #ifdef CONFIG_BINFMT_ELF_FDPIC
924 case PTRACE_GETFDPIC: {
925 struct mm_struct *mm = get_task_mm(child);
926 unsigned long tmp = 0;
933 case PTRACE_GETFDPIC_EXEC:
934 tmp = mm->context.exec_fdpic_loadmap;
936 case PTRACE_GETFDPIC_INTERP:
937 tmp = mm->context.interp_fdpic_loadmap;
944 ret = put_user(tmp, datalp);
949 #ifdef PTRACE_SINGLESTEP
950 case PTRACE_SINGLESTEP:
952 #ifdef PTRACE_SINGLEBLOCK
953 case PTRACE_SINGLEBLOCK:
957 case PTRACE_SYSEMU_SINGLESTEP:
961 return ptrace_resume(child, request, data);
964 if (child->exit_state) /* already dead */
966 return ptrace_resume(child, request, SIGKILL);
968 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
969 case PTRACE_GETREGSET:
970 case PTRACE_SETREGSET: {
972 struct iovec __user *uiov = datavp;
974 if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov)))
977 if (__get_user(kiov.iov_base, &uiov->iov_base) ||
978 __get_user(kiov.iov_len, &uiov->iov_len))
981 ret = ptrace_regset(child, request, addr, &kiov);
983 ret = __put_user(kiov.iov_len, &uiov->iov_len);
994 static struct task_struct *ptrace_get_task_struct(pid_t pid)
996 struct task_struct *child;
999 child = find_task_by_vpid(pid);
1001 get_task_struct(child);
1005 return ERR_PTR(-ESRCH);
1009 #ifndef arch_ptrace_attach
1010 #define arch_ptrace_attach(child) do { } while (0)
1013 SYSCALL_DEFINE4(ptrace, long, request, long, pid, unsigned long, addr,
1014 unsigned long, data)
1016 struct task_struct *child;
1019 if (request == PTRACE_TRACEME) {
1020 ret = ptrace_traceme();
1022 arch_ptrace_attach(current);
1026 child = ptrace_get_task_struct(pid);
1027 if (IS_ERR(child)) {
1028 ret = PTR_ERR(child);
1032 if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) {
1033 ret = ptrace_attach(child, request, addr, data);
1035 * Some architectures need to do book-keeping after
1039 arch_ptrace_attach(child);
1040 goto out_put_task_struct;
1043 ret = ptrace_check_attach(child, request == PTRACE_KILL ||
1044 request == PTRACE_INTERRUPT);
1046 goto out_put_task_struct;
1048 ret = arch_ptrace(child, request, addr, data);
1049 if (ret || request != PTRACE_DETACH)
1050 ptrace_unfreeze_traced(child);
1052 out_put_task_struct:
1053 put_task_struct(child);
1058 int generic_ptrace_peekdata(struct task_struct *tsk, unsigned long addr,
1064 copied = access_process_vm(tsk, addr, &tmp, sizeof(tmp), 0);
1065 if (copied != sizeof(tmp))
1067 return put_user(tmp, (unsigned long __user *)data);
1070 int generic_ptrace_pokedata(struct task_struct *tsk, unsigned long addr,
1075 copied = access_process_vm(tsk, addr, &data, sizeof(data), 1);
1076 return (copied == sizeof(data)) ? 0 : -EIO;
1079 #if defined CONFIG_COMPAT
1080 #include <linux/compat.h>
1082 int compat_ptrace_request(struct task_struct *child, compat_long_t request,
1083 compat_ulong_t addr, compat_ulong_t data)
1085 compat_ulong_t __user *datap = compat_ptr(data);
1086 compat_ulong_t word;
1091 case PTRACE_PEEKTEXT:
1092 case PTRACE_PEEKDATA:
1093 ret = access_process_vm(child, addr, &word, sizeof(word), 0);
1094 if (ret != sizeof(word))
1097 ret = put_user(word, datap);
1100 case PTRACE_POKETEXT:
1101 case PTRACE_POKEDATA:
1102 ret = access_process_vm(child, addr, &data, sizeof(data), 1);
1103 ret = (ret != sizeof(data) ? -EIO : 0);
1106 case PTRACE_GETEVENTMSG:
1107 ret = put_user((compat_ulong_t) child->ptrace_message, datap);
1110 case PTRACE_GETSIGINFO:
1111 ret = ptrace_getsiginfo(child, &siginfo);
1113 ret = copy_siginfo_to_user32(
1114 (struct compat_siginfo __user *) datap,
1118 case PTRACE_SETSIGINFO:
1119 memset(&siginfo, 0, sizeof siginfo);
1120 if (copy_siginfo_from_user32(
1121 &siginfo, (struct compat_siginfo __user *) datap))
1124 ret = ptrace_setsiginfo(child, &siginfo);
1126 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
1127 case PTRACE_GETREGSET:
1128 case PTRACE_SETREGSET:
1131 struct compat_iovec __user *uiov =
1132 (struct compat_iovec __user *) datap;
1136 if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov)))
1139 if (__get_user(ptr, &uiov->iov_base) ||
1140 __get_user(len, &uiov->iov_len))
1143 kiov.iov_base = compat_ptr(ptr);
1146 ret = ptrace_regset(child, request, addr, &kiov);
1148 ret = __put_user(kiov.iov_len, &uiov->iov_len);
1154 ret = ptrace_request(child, request, addr, data);
1160 COMPAT_SYSCALL_DEFINE4(ptrace, compat_long_t, request, compat_long_t, pid,
1161 compat_long_t, addr, compat_long_t, data)
1163 struct task_struct *child;
1166 if (request == PTRACE_TRACEME) {
1167 ret = ptrace_traceme();
1171 child = ptrace_get_task_struct(pid);
1172 if (IS_ERR(child)) {
1173 ret = PTR_ERR(child);
1177 if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) {
1178 ret = ptrace_attach(child, request, addr, data);
1180 * Some architectures need to do book-keeping after
1184 arch_ptrace_attach(child);
1185 goto out_put_task_struct;
1188 ret = ptrace_check_attach(child, request == PTRACE_KILL ||
1189 request == PTRACE_INTERRUPT);
1191 ret = compat_arch_ptrace(child, request, addr, data);
1192 if (ret || request != PTRACE_DETACH)
1193 ptrace_unfreeze_traced(child);
1196 out_put_task_struct:
1197 put_task_struct(child);
1201 #endif /* CONFIG_COMPAT */