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);
151 spin_lock_irq(&task->sighand->siglock);
152 if (__fatal_signal_pending(task))
153 wake_up_state(task, __TASK_TRACED);
155 task->state = TASK_TRACED;
156 spin_unlock_irq(&task->sighand->siglock);
160 * ptrace_check_attach - check whether ptracee is ready for ptrace operation
161 * @child: ptracee to check for
162 * @ignore_state: don't check whether @child is currently %TASK_TRACED
164 * Check whether @child is being ptraced by %current and ready for further
165 * ptrace operations. If @ignore_state is %false, @child also should be in
166 * %TASK_TRACED state and on return the child is guaranteed to be traced
167 * and not executing. If @ignore_state is %true, @child can be in any
171 * Grabs and releases tasklist_lock and @child->sighand->siglock.
174 * 0 on success, -ESRCH if %child is not ready.
176 int ptrace_check_attach(struct task_struct *child, bool ignore_state)
181 * We take the read lock around doing both checks to close a
182 * possible race where someone else was tracing our child and
183 * detached between these two checks. After this locked check,
184 * we are sure that this is our traced child and that can only
185 * be changed by us so it's not changing right after this.
187 read_lock(&tasklist_lock);
188 if (child->ptrace && child->parent == current) {
189 WARN_ON(child->state == __TASK_TRACED);
191 * child->sighand can't be NULL, release_task()
192 * does ptrace_unlink() before __exit_signal().
194 if (ignore_state || ptrace_freeze_traced(child))
197 read_unlock(&tasklist_lock);
199 if (!ret && !ignore_state) {
200 if (!wait_task_inactive(child, __TASK_TRACED)) {
202 * This can only happen if may_ptrace_stop() fails and
203 * ptrace_stop() changes ->state back to TASK_RUNNING,
204 * so we should not worry about leaking __TASK_TRACED.
206 WARN_ON(child->state == __TASK_TRACED);
214 static int ptrace_has_cap(struct user_namespace *ns, unsigned int mode)
216 if (mode & PTRACE_MODE_NOAUDIT)
217 return has_ns_capability_noaudit(current, ns, CAP_SYS_PTRACE);
219 return has_ns_capability(current, ns, CAP_SYS_PTRACE);
222 int __ptrace_may_access(struct task_struct *task, unsigned int mode)
224 const struct cred *cred = current_cred(), *tcred;
226 /* May we inspect the given task?
227 * This check is used both for attaching with ptrace
228 * and for allowing access to sensitive information in /proc.
230 * ptrace_attach denies several cases that /proc allows
231 * because setting up the necessary parent/child relationship
232 * or halting the specified task is impossible.
235 /* Don't let security modules deny introspection */
239 tcred = __task_cred(task);
240 if (cred->user->user_ns == tcred->user->user_ns &&
241 (cred->uid == tcred->euid &&
242 cred->uid == tcred->suid &&
243 cred->uid == tcred->uid &&
244 cred->gid == tcred->egid &&
245 cred->gid == tcred->sgid &&
246 cred->gid == tcred->gid))
248 if (ptrace_has_cap(tcred->user->user_ns, mode))
256 dumpable = get_dumpable(task->mm);
257 if (!dumpable && !ptrace_has_cap(task_user_ns(task), mode))
260 return security_ptrace_access_check(task, mode);
263 bool ptrace_may_access(struct task_struct *task, unsigned int mode)
267 err = __ptrace_may_access(task, mode);
272 static int ptrace_attach(struct task_struct *task, long request,
276 bool seize = (request == PTRACE_SEIZE);
283 if (flags & ~(unsigned long)PTRACE_O_MASK)
285 flags = PT_PTRACED | PT_SEIZED | (flags << PT_OPT_FLAG_SHIFT);
293 if (unlikely(task->flags & PF_KTHREAD))
295 if (same_thread_group(task, current))
299 * Protect exec's credential calculations against our interference;
300 * SUID, SGID and LSM creds get determined differently
303 retval = -ERESTARTNOINTR;
304 if (mutex_lock_interruptible(&task->signal->cred_guard_mutex))
308 retval = __ptrace_may_access(task, PTRACE_MODE_ATTACH);
313 write_lock_irq(&tasklist_lock);
315 if (unlikely(task->exit_state))
316 goto unlock_tasklist;
318 goto unlock_tasklist;
322 if (ns_capable(task_user_ns(task), CAP_SYS_PTRACE))
323 flags |= PT_PTRACE_CAP;
324 task->ptrace = flags;
326 __ptrace_link(task, current);
328 /* SEIZE doesn't trap tracee on attach */
330 send_sig_info(SIGSTOP, SEND_SIG_FORCED, task);
332 spin_lock(&task->sighand->siglock);
335 * If the task is already STOPPED, set JOBCTL_TRAP_STOP and
336 * TRAPPING, and kick it so that it transits to TRACED. TRAPPING
337 * will be cleared if the child completes the transition or any
338 * event which clears the group stop states happens. We'll wait
339 * for the transition to complete before returning from this
342 * This hides STOPPED -> RUNNING -> TRACED transition from the
343 * attaching thread but a different thread in the same group can
344 * still observe the transient RUNNING state. IOW, if another
345 * thread's WNOHANG wait(2) on the stopped tracee races against
346 * ATTACH, the wait(2) may fail due to the transient RUNNING.
348 * The following task_is_stopped() test is safe as both transitions
349 * in and out of STOPPED are protected by siglock.
351 if (task_is_stopped(task) &&
352 task_set_jobctl_pending(task, JOBCTL_TRAP_STOP | JOBCTL_TRAPPING))
353 signal_wake_up_state(task, __TASK_STOPPED);
355 spin_unlock(&task->sighand->siglock);
359 write_unlock_irq(&tasklist_lock);
361 mutex_unlock(&task->signal->cred_guard_mutex);
364 wait_on_bit(&task->jobctl, JOBCTL_TRAPPING_BIT,
365 ptrace_trapping_sleep_fn, TASK_UNINTERRUPTIBLE);
366 proc_ptrace_connector(task, PTRACE_ATTACH);
373 * ptrace_traceme -- helper for PTRACE_TRACEME
375 * Performs checks and sets PT_PTRACED.
376 * Should be used by all ptrace implementations for PTRACE_TRACEME.
378 static int ptrace_traceme(void)
382 write_lock_irq(&tasklist_lock);
383 /* Are we already being traced? */
384 if (!current->ptrace) {
385 ret = security_ptrace_traceme(current->parent);
387 * Check PF_EXITING to ensure ->real_parent has not passed
388 * exit_ptrace(). Otherwise we don't report the error but
389 * pretend ->real_parent untraces us right after return.
391 if (!ret && !(current->real_parent->flags & PF_EXITING)) {
392 current->ptrace = PT_PTRACED;
393 __ptrace_link(current, current->real_parent);
396 write_unlock_irq(&tasklist_lock);
402 * Called with irqs disabled, returns true if childs should reap themselves.
404 static int ignoring_children(struct sighand_struct *sigh)
407 spin_lock(&sigh->siglock);
408 ret = (sigh->action[SIGCHLD-1].sa.sa_handler == SIG_IGN) ||
409 (sigh->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT);
410 spin_unlock(&sigh->siglock);
415 * Called with tasklist_lock held for writing.
416 * Unlink a traced task, and clean it up if it was a traced zombie.
417 * Return true if it needs to be reaped with release_task().
418 * (We can't call release_task() here because we already hold tasklist_lock.)
420 * If it's a zombie, our attachedness prevented normal parent notification
421 * or self-reaping. Do notification now if it would have happened earlier.
422 * If it should reap itself, return true.
424 * If it's our own child, there is no notification to do. But if our normal
425 * children self-reap, then this child was prevented by ptrace and we must
426 * reap it now, in that case we must also wake up sub-threads sleeping in
429 static bool __ptrace_detach(struct task_struct *tracer, struct task_struct *p)
435 if (p->exit_state != EXIT_ZOMBIE)
438 dead = !thread_group_leader(p);
440 if (!dead && thread_group_empty(p)) {
441 if (!same_thread_group(p->real_parent, tracer))
442 dead = do_notify_parent(p, p->exit_signal);
443 else if (ignoring_children(tracer->sighand)) {
444 __wake_up_parent(p, tracer);
448 /* Mark it as in the process of being reaped. */
450 p->exit_state = EXIT_DEAD;
454 static int ptrace_detach(struct task_struct *child, unsigned int data)
458 if (!valid_signal(data))
461 /* Architecture-specific hardware disable .. */
462 ptrace_disable(child);
463 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
465 write_lock_irq(&tasklist_lock);
467 * This child can be already killed. Make sure de_thread() or
468 * our sub-thread doing do_wait() didn't do release_task() yet.
471 child->exit_code = data;
472 dead = __ptrace_detach(current, child);
474 write_unlock_irq(&tasklist_lock);
476 proc_ptrace_connector(child, PTRACE_DETACH);
484 * Detach all tasks we were using ptrace on. Called with tasklist held
485 * for writing, and returns with it held too. But note it can release
486 * and reacquire the lock.
488 void exit_ptrace(struct task_struct *tracer)
489 __releases(&tasklist_lock)
490 __acquires(&tasklist_lock)
492 struct task_struct *p, *n;
493 LIST_HEAD(ptrace_dead);
495 if (likely(list_empty(&tracer->ptraced)))
498 list_for_each_entry_safe(p, n, &tracer->ptraced, ptrace_entry) {
499 if (__ptrace_detach(tracer, p))
500 list_add(&p->ptrace_entry, &ptrace_dead);
503 write_unlock_irq(&tasklist_lock);
504 BUG_ON(!list_empty(&tracer->ptraced));
506 list_for_each_entry_safe(p, n, &ptrace_dead, ptrace_entry) {
507 list_del_init(&p->ptrace_entry);
511 write_lock_irq(&tasklist_lock);
514 int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len)
520 int this_len, retval;
522 this_len = (len > sizeof(buf)) ? sizeof(buf) : len;
523 retval = access_process_vm(tsk, src, buf, this_len, 0);
529 if (copy_to_user(dst, buf, retval))
539 int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len)
545 int this_len, retval;
547 this_len = (len > sizeof(buf)) ? sizeof(buf) : len;
548 if (copy_from_user(buf, src, this_len))
550 retval = access_process_vm(tsk, dst, buf, this_len, 1);
564 static int ptrace_setoptions(struct task_struct *child, unsigned long data)
568 if (data & ~(unsigned long)PTRACE_O_MASK)
571 /* Avoid intermediate state when all opts are cleared */
572 flags = child->ptrace;
573 flags &= ~(PTRACE_O_MASK << PT_OPT_FLAG_SHIFT);
574 flags |= (data << PT_OPT_FLAG_SHIFT);
575 child->ptrace = flags;
577 if (data & PTRACE_O_TRACESECCOMP)
578 child->ptrace |= PT_TRACE_SECCOMP;
583 static int ptrace_getsiginfo(struct task_struct *child, siginfo_t *info)
588 if (lock_task_sighand(child, &flags)) {
590 if (likely(child->last_siginfo != NULL)) {
591 *info = *child->last_siginfo;
594 unlock_task_sighand(child, &flags);
599 static int ptrace_setsiginfo(struct task_struct *child, const siginfo_t *info)
604 if (lock_task_sighand(child, &flags)) {
606 if (likely(child->last_siginfo != NULL)) {
607 *child->last_siginfo = *info;
610 unlock_task_sighand(child, &flags);
616 #ifdef PTRACE_SINGLESTEP
617 #define is_singlestep(request) ((request) == PTRACE_SINGLESTEP)
619 #define is_singlestep(request) 0
622 #ifdef PTRACE_SINGLEBLOCK
623 #define is_singleblock(request) ((request) == PTRACE_SINGLEBLOCK)
625 #define is_singleblock(request) 0
629 #define is_sysemu_singlestep(request) ((request) == PTRACE_SYSEMU_SINGLESTEP)
631 #define is_sysemu_singlestep(request) 0
634 static int ptrace_resume(struct task_struct *child, long request,
637 if (!valid_signal(data))
640 if (request == PTRACE_SYSCALL)
641 set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
643 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
645 #ifdef TIF_SYSCALL_EMU
646 if (request == PTRACE_SYSEMU || request == PTRACE_SYSEMU_SINGLESTEP)
647 set_tsk_thread_flag(child, TIF_SYSCALL_EMU);
649 clear_tsk_thread_flag(child, TIF_SYSCALL_EMU);
652 if (is_singleblock(request)) {
653 if (unlikely(!arch_has_block_step()))
655 user_enable_block_step(child);
656 } else if (is_singlestep(request) || is_sysemu_singlestep(request)) {
657 if (unlikely(!arch_has_single_step()))
659 user_enable_single_step(child);
661 user_disable_single_step(child);
664 child->exit_code = data;
665 wake_up_state(child, __TASK_TRACED);
670 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
672 static const struct user_regset *
673 find_regset(const struct user_regset_view *view, unsigned int type)
675 const struct user_regset *regset;
678 for (n = 0; n < view->n; ++n) {
679 regset = view->regsets + n;
680 if (regset->core_note_type == type)
687 static int ptrace_regset(struct task_struct *task, int req, unsigned int type,
690 const struct user_regset_view *view = task_user_regset_view(task);
691 const struct user_regset *regset = find_regset(view, type);
694 if (!regset || (kiov->iov_len % regset->size) != 0)
697 regset_no = regset - view->regsets;
698 kiov->iov_len = min(kiov->iov_len,
699 (__kernel_size_t) (regset->n * regset->size));
701 if (req == PTRACE_GETREGSET)
702 return copy_regset_to_user(task, view, regset_no, 0,
703 kiov->iov_len, kiov->iov_base);
705 return copy_regset_from_user(task, view, regset_no, 0,
706 kiov->iov_len, kiov->iov_base);
711 int ptrace_request(struct task_struct *child, long request,
712 unsigned long addr, unsigned long data)
714 bool seized = child->ptrace & PT_SEIZED;
716 siginfo_t siginfo, *si;
717 void __user *datavp = (void __user *) data;
718 unsigned long __user *datalp = datavp;
722 case PTRACE_PEEKTEXT:
723 case PTRACE_PEEKDATA:
724 return generic_ptrace_peekdata(child, addr, data);
725 case PTRACE_POKETEXT:
726 case PTRACE_POKEDATA:
727 return generic_ptrace_pokedata(child, addr, data);
729 #ifdef PTRACE_OLDSETOPTIONS
730 case PTRACE_OLDSETOPTIONS:
732 case PTRACE_SETOPTIONS:
733 ret = ptrace_setoptions(child, data);
735 case PTRACE_GETEVENTMSG:
736 ret = put_user(child->ptrace_message, datalp);
739 case PTRACE_GETSIGINFO:
740 ret = ptrace_getsiginfo(child, &siginfo);
742 ret = copy_siginfo_to_user(datavp, &siginfo);
745 case PTRACE_SETSIGINFO:
746 if (copy_from_user(&siginfo, datavp, sizeof siginfo))
749 ret = ptrace_setsiginfo(child, &siginfo);
752 case PTRACE_INTERRUPT:
754 * Stop tracee without any side-effect on signal or job
755 * control. At least one trap is guaranteed to happen
756 * after this request. If @child is already trapped, the
757 * current trap is not disturbed and another trap will
758 * happen after the current trap is ended with PTRACE_CONT.
760 * The actual trap might not be PTRACE_EVENT_STOP trap but
761 * the pending condition is cleared regardless.
763 if (unlikely(!seized || !lock_task_sighand(child, &flags)))
767 * INTERRUPT doesn't disturb existing trap sans one
768 * exception. If ptracer issued LISTEN for the current
769 * STOP, this INTERRUPT should clear LISTEN and re-trap
772 if (likely(task_set_jobctl_pending(child, JOBCTL_TRAP_STOP)))
773 ptrace_signal_wake_up(child, child->jobctl & JOBCTL_LISTENING);
775 unlock_task_sighand(child, &flags);
781 * Listen for events. Tracee must be in STOP. It's not
782 * resumed per-se but is not considered to be in TRACED by
783 * wait(2) or ptrace(2). If an async event (e.g. group
784 * stop state change) happens, tracee will enter STOP trap
785 * again. Alternatively, ptracer can issue INTERRUPT to
786 * finish listening and re-trap tracee into STOP.
788 if (unlikely(!seized || !lock_task_sighand(child, &flags)))
791 si = child->last_siginfo;
792 if (likely(si && (si->si_code >> 8) == PTRACE_EVENT_STOP)) {
793 child->jobctl |= JOBCTL_LISTENING;
795 * If NOTIFY is set, it means event happened between
796 * start of this trap and now. Trigger re-trap.
798 if (child->jobctl & JOBCTL_TRAP_NOTIFY)
799 ptrace_signal_wake_up(child, true);
802 unlock_task_sighand(child, &flags);
805 case PTRACE_DETACH: /* detach a process that was attached. */
806 ret = ptrace_detach(child, data);
809 #ifdef CONFIG_BINFMT_ELF_FDPIC
810 case PTRACE_GETFDPIC: {
811 struct mm_struct *mm = get_task_mm(child);
812 unsigned long tmp = 0;
819 case PTRACE_GETFDPIC_EXEC:
820 tmp = mm->context.exec_fdpic_loadmap;
822 case PTRACE_GETFDPIC_INTERP:
823 tmp = mm->context.interp_fdpic_loadmap;
830 ret = put_user(tmp, datalp);
835 #ifdef PTRACE_SINGLESTEP
836 case PTRACE_SINGLESTEP:
838 #ifdef PTRACE_SINGLEBLOCK
839 case PTRACE_SINGLEBLOCK:
843 case PTRACE_SYSEMU_SINGLESTEP:
847 return ptrace_resume(child, request, data);
850 if (child->exit_state) /* already dead */
852 return ptrace_resume(child, request, SIGKILL);
854 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
855 case PTRACE_GETREGSET:
856 case PTRACE_SETREGSET:
859 struct iovec __user *uiov = datavp;
861 if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov)))
864 if (__get_user(kiov.iov_base, &uiov->iov_base) ||
865 __get_user(kiov.iov_len, &uiov->iov_len))
868 ret = ptrace_regset(child, request, addr, &kiov);
870 ret = __put_user(kiov.iov_len, &uiov->iov_len);
881 static struct task_struct *ptrace_get_task_struct(pid_t pid)
883 struct task_struct *child;
886 child = find_task_by_vpid(pid);
888 get_task_struct(child);
892 return ERR_PTR(-ESRCH);
896 #ifndef arch_ptrace_attach
897 #define arch_ptrace_attach(child) do { } while (0)
900 SYSCALL_DEFINE4(ptrace, long, request, long, pid, unsigned long, addr,
903 struct task_struct *child;
906 if (request == PTRACE_TRACEME) {
907 ret = ptrace_traceme();
909 arch_ptrace_attach(current);
913 child = ptrace_get_task_struct(pid);
915 ret = PTR_ERR(child);
919 if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) {
920 ret = ptrace_attach(child, request, addr, data);
922 * Some architectures need to do book-keeping after
926 arch_ptrace_attach(child);
927 goto out_put_task_struct;
930 ret = ptrace_check_attach(child, request == PTRACE_KILL ||
931 request == PTRACE_INTERRUPT);
933 goto out_put_task_struct;
935 ret = arch_ptrace(child, request, addr, data);
936 if (ret || request != PTRACE_DETACH)
937 ptrace_unfreeze_traced(child);
940 put_task_struct(child);
945 int generic_ptrace_peekdata(struct task_struct *tsk, unsigned long addr,
951 copied = access_process_vm(tsk, addr, &tmp, sizeof(tmp), 0);
952 if (copied != sizeof(tmp))
954 return put_user(tmp, (unsigned long __user *)data);
957 int generic_ptrace_pokedata(struct task_struct *tsk, unsigned long addr,
962 copied = access_process_vm(tsk, addr, &data, sizeof(data), 1);
963 return (copied == sizeof(data)) ? 0 : -EIO;
966 #if defined CONFIG_COMPAT
967 #include <linux/compat.h>
969 int compat_ptrace_request(struct task_struct *child, compat_long_t request,
970 compat_ulong_t addr, compat_ulong_t data)
972 compat_ulong_t __user *datap = compat_ptr(data);
978 case PTRACE_PEEKTEXT:
979 case PTRACE_PEEKDATA:
980 ret = access_process_vm(child, addr, &word, sizeof(word), 0);
981 if (ret != sizeof(word))
984 ret = put_user(word, datap);
987 case PTRACE_POKETEXT:
988 case PTRACE_POKEDATA:
989 ret = access_process_vm(child, addr, &data, sizeof(data), 1);
990 ret = (ret != sizeof(data) ? -EIO : 0);
993 case PTRACE_GETEVENTMSG:
994 ret = put_user((compat_ulong_t) child->ptrace_message, datap);
997 case PTRACE_GETSIGINFO:
998 ret = ptrace_getsiginfo(child, &siginfo);
1000 ret = copy_siginfo_to_user32(
1001 (struct compat_siginfo __user *) datap,
1005 case PTRACE_SETSIGINFO:
1006 memset(&siginfo, 0, sizeof siginfo);
1007 if (copy_siginfo_from_user32(
1008 &siginfo, (struct compat_siginfo __user *) datap))
1011 ret = ptrace_setsiginfo(child, &siginfo);
1013 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
1014 case PTRACE_GETREGSET:
1015 case PTRACE_SETREGSET:
1018 struct compat_iovec __user *uiov =
1019 (struct compat_iovec __user *) datap;
1023 if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov)))
1026 if (__get_user(ptr, &uiov->iov_base) ||
1027 __get_user(len, &uiov->iov_len))
1030 kiov.iov_base = compat_ptr(ptr);
1033 ret = ptrace_regset(child, request, addr, &kiov);
1035 ret = __put_user(kiov.iov_len, &uiov->iov_len);
1041 ret = ptrace_request(child, request, addr, data);
1047 asmlinkage long compat_sys_ptrace(compat_long_t request, compat_long_t pid,
1048 compat_long_t addr, compat_long_t data)
1050 struct task_struct *child;
1053 if (request == PTRACE_TRACEME) {
1054 ret = ptrace_traceme();
1058 child = ptrace_get_task_struct(pid);
1059 if (IS_ERR(child)) {
1060 ret = PTR_ERR(child);
1064 if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) {
1065 ret = ptrace_attach(child, request, addr, data);
1067 * Some architectures need to do book-keeping after
1071 arch_ptrace_attach(child);
1072 goto out_put_task_struct;
1075 ret = ptrace_check_attach(child, request == PTRACE_KILL ||
1076 request == PTRACE_INTERRUPT);
1078 ret = compat_arch_ptrace(child, request, addr, data);
1079 if (ret || request != PTRACE_DETACH)
1080 ptrace_unfreeze_traced(child);
1083 out_put_task_struct:
1084 put_task_struct(child);
1088 #endif /* CONFIG_COMPAT */
1090 #ifdef CONFIG_HAVE_HW_BREAKPOINT
1091 int ptrace_get_breakpoints(struct task_struct *tsk)
1093 if (atomic_inc_not_zero(&tsk->ptrace_bp_refcnt))
1099 void ptrace_put_breakpoints(struct task_struct *tsk)
1101 if (atomic_dec_and_test(&tsk->ptrace_bp_refcnt))
1102 flush_ptrace_hw_breakpoint(tsk);
1104 #endif /* CONFIG_HAVE_HW_BREAKPOINT */