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/module.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>
28 static int ptrace_trapping_sleep_fn(void *flags)
35 * ptrace a task: make the debugger its new parent and
36 * move it to the ptrace list.
38 * Must be called with the tasklist lock write-held.
40 void __ptrace_link(struct task_struct *child, struct task_struct *new_parent)
42 BUG_ON(!list_empty(&child->ptrace_entry));
43 list_add(&child->ptrace_entry, &new_parent->ptraced);
44 child->parent = new_parent;
48 * __ptrace_unlink - unlink ptracee and restore its execution state
49 * @child: ptracee to be unlinked
51 * Remove @child from the ptrace list, move it back to the original parent,
52 * and restore the execution state so that it conforms to the group stop
55 * Unlinking can happen via two paths - explicit PTRACE_DETACH or ptracer
56 * exiting. For PTRACE_DETACH, unless the ptracee has been killed between
57 * ptrace_check_attach() and here, it's guaranteed to be in TASK_TRACED.
58 * If the ptracer is exiting, the ptracee can be in any state.
60 * After detach, the ptracee should be in a state which conforms to the
61 * group stop. If the group is stopped or in the process of stopping, the
62 * ptracee should be put into TASK_STOPPED; otherwise, it should be woken
63 * up from TASK_TRACED.
65 * If the ptracee is in TASK_TRACED and needs to be moved to TASK_STOPPED,
66 * it goes through TRACED -> RUNNING -> STOPPED transition which is similar
67 * to but in the opposite direction of what happens while attaching to a
68 * stopped task. However, in this direction, the intermediate RUNNING
69 * state is not hidden even from the current ptracer and if it immediately
70 * re-attaches and performs a WNOHANG wait(2), it may fail.
73 * write_lock_irq(tasklist_lock)
75 void __ptrace_unlink(struct task_struct *child)
77 BUG_ON(!child->ptrace);
80 child->parent = child->real_parent;
81 list_del_init(&child->ptrace_entry);
83 spin_lock(&child->sighand->siglock);
86 * Clear all pending traps and TRAPPING. TRAPPING should be
87 * cleared regardless of JOBCTL_STOP_PENDING. Do it explicitly.
89 task_clear_jobctl_pending(child, JOBCTL_TRAP_MASK);
90 task_clear_jobctl_trapping(child);
93 * Reinstate JOBCTL_STOP_PENDING if group stop is in effect and
96 if (!(child->flags & PF_EXITING) &&
97 (child->signal->flags & SIGNAL_STOP_STOPPED ||
98 child->signal->group_stop_count))
99 child->jobctl |= JOBCTL_STOP_PENDING;
102 * If transition to TASK_STOPPED is pending or in TASK_TRACED, kick
103 * @child in the butt. Note that @resume should be used iff @child
104 * is in TASK_TRACED; otherwise, we might unduly disrupt
105 * TASK_KILLABLE sleeps.
107 if (child->jobctl & JOBCTL_STOP_PENDING || task_is_traced(child))
108 signal_wake_up(child, task_is_traced(child));
110 spin_unlock(&child->sighand->siglock);
114 * ptrace_check_attach - check whether ptracee is ready for ptrace operation
115 * @child: ptracee to check for
116 * @ignore_state: don't check whether @child is currently %TASK_TRACED
118 * Check whether @child is being ptraced by %current and ready for further
119 * ptrace operations. If @ignore_state is %false, @child also should be in
120 * %TASK_TRACED state and on return the child is guaranteed to be traced
121 * and not executing. If @ignore_state is %true, @child can be in any
125 * Grabs and releases tasklist_lock and @child->sighand->siglock.
128 * 0 on success, -ESRCH if %child is not ready.
130 int ptrace_check_attach(struct task_struct *child, bool ignore_state)
135 * We take the read lock around doing both checks to close a
136 * possible race where someone else was tracing our child and
137 * detached between these two checks. After this locked check,
138 * we are sure that this is our traced child and that can only
139 * be changed by us so it's not changing right after this.
141 read_lock(&tasklist_lock);
142 if ((child->ptrace & PT_PTRACED) && child->parent == current) {
144 * child->sighand can't be NULL, release_task()
145 * does ptrace_unlink() before __exit_signal().
147 spin_lock_irq(&child->sighand->siglock);
148 WARN_ON_ONCE(task_is_stopped(child));
149 if (task_is_traced(child) || ignore_state)
151 spin_unlock_irq(&child->sighand->siglock);
153 read_unlock(&tasklist_lock);
155 if (!ret && !ignore_state)
156 ret = wait_task_inactive(child, TASK_TRACED) ? 0 : -ESRCH;
158 /* All systems go.. */
162 int __ptrace_may_access(struct task_struct *task, unsigned int mode)
164 const struct cred *cred = current_cred(), *tcred;
166 /* May we inspect the given task?
167 * This check is used both for attaching with ptrace
168 * and for allowing access to sensitive information in /proc.
170 * ptrace_attach denies several cases that /proc allows
171 * because setting up the necessary parent/child relationship
172 * or halting the specified task is impossible.
175 /* Don't let security modules deny introspection */
179 tcred = __task_cred(task);
180 if (cred->user->user_ns == tcred->user->user_ns &&
181 (cred->uid == tcred->euid &&
182 cred->uid == tcred->suid &&
183 cred->uid == tcred->uid &&
184 cred->gid == tcred->egid &&
185 cred->gid == tcred->sgid &&
186 cred->gid == tcred->gid))
188 if (ns_capable(tcred->user->user_ns, CAP_SYS_PTRACE))
196 dumpable = get_dumpable(task->mm);
197 if (!dumpable && !task_ns_capable(task, CAP_SYS_PTRACE))
200 return security_ptrace_access_check(task, mode);
203 bool ptrace_may_access(struct task_struct *task, unsigned int mode)
207 err = __ptrace_may_access(task, mode);
212 static int ptrace_attach(struct task_struct *task, long request,
215 bool seize = (request == PTRACE_SEIZE);
219 * SEIZE will enable new ptrace behaviors which will be implemented
220 * gradually. SEIZE_DEVEL is used to prevent applications
221 * expecting full SEIZE behaviors trapping on kernel commits which
222 * are still in the process of implementing them.
224 * Only test programs for new ptrace behaviors being implemented
225 * should set SEIZE_DEVEL. If unset, SEIZE will fail with -EIO.
227 * Once SEIZE behaviors are completely implemented, this flag and
228 * the following test will be removed.
231 if (seize && !(flags & PTRACE_SEIZE_DEVEL))
237 if (unlikely(task->flags & PF_KTHREAD))
239 if (same_thread_group(task, current))
243 * Protect exec's credential calculations against our interference;
244 * interference; SUID, SGID and LSM creds get determined differently
247 retval = -ERESTARTNOINTR;
248 if (mutex_lock_interruptible(&task->signal->cred_guard_mutex))
252 retval = __ptrace_may_access(task, PTRACE_MODE_ATTACH);
257 write_lock_irq(&tasklist_lock);
259 if (unlikely(task->exit_state))
260 goto unlock_tasklist;
262 goto unlock_tasklist;
264 task->ptrace = PT_PTRACED;
266 task->ptrace |= PT_SEIZED;
267 if (task_ns_capable(task, CAP_SYS_PTRACE))
268 task->ptrace |= PT_PTRACE_CAP;
270 __ptrace_link(task, current);
272 /* SEIZE doesn't trap tracee on attach */
274 send_sig_info(SIGSTOP, SEND_SIG_FORCED, task);
276 spin_lock(&task->sighand->siglock);
279 * If the task is already STOPPED, set JOBCTL_TRAP_STOP and
280 * TRAPPING, and kick it so that it transits to TRACED. TRAPPING
281 * will be cleared if the child completes the transition or any
282 * event which clears the group stop states happens. We'll wait
283 * for the transition to complete before returning from this
286 * This hides STOPPED -> RUNNING -> TRACED transition from the
287 * attaching thread but a different thread in the same group can
288 * still observe the transient RUNNING state. IOW, if another
289 * thread's WNOHANG wait(2) on the stopped tracee races against
290 * ATTACH, the wait(2) may fail due to the transient RUNNING.
292 * The following task_is_stopped() test is safe as both transitions
293 * in and out of STOPPED are protected by siglock.
295 if (task_is_stopped(task) &&
296 task_set_jobctl_pending(task, JOBCTL_TRAP_STOP | JOBCTL_TRAPPING))
297 signal_wake_up(task, 1);
299 spin_unlock(&task->sighand->siglock);
303 write_unlock_irq(&tasklist_lock);
305 mutex_unlock(&task->signal->cred_guard_mutex);
308 wait_on_bit(&task->jobctl, JOBCTL_TRAPPING_BIT,
309 ptrace_trapping_sleep_fn, TASK_UNINTERRUPTIBLE);
314 * ptrace_traceme -- helper for PTRACE_TRACEME
316 * Performs checks and sets PT_PTRACED.
317 * Should be used by all ptrace implementations for PTRACE_TRACEME.
319 static int ptrace_traceme(void)
323 write_lock_irq(&tasklist_lock);
324 /* Are we already being traced? */
325 if (!current->ptrace) {
326 ret = security_ptrace_traceme(current->parent);
328 * Check PF_EXITING to ensure ->real_parent has not passed
329 * exit_ptrace(). Otherwise we don't report the error but
330 * pretend ->real_parent untraces us right after return.
332 if (!ret && !(current->real_parent->flags & PF_EXITING)) {
333 current->ptrace = PT_PTRACED;
334 __ptrace_link(current, current->real_parent);
337 write_unlock_irq(&tasklist_lock);
343 * Called with irqs disabled, returns true if childs should reap themselves.
345 static int ignoring_children(struct sighand_struct *sigh)
348 spin_lock(&sigh->siglock);
349 ret = (sigh->action[SIGCHLD-1].sa.sa_handler == SIG_IGN) ||
350 (sigh->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT);
351 spin_unlock(&sigh->siglock);
356 * Called with tasklist_lock held for writing.
357 * Unlink a traced task, and clean it up if it was a traced zombie.
358 * Return true if it needs to be reaped with release_task().
359 * (We can't call release_task() here because we already hold tasklist_lock.)
361 * If it's a zombie, our attachedness prevented normal parent notification
362 * or self-reaping. Do notification now if it would have happened earlier.
363 * If it should reap itself, return true.
365 * If it's our own child, there is no notification to do. But if our normal
366 * children self-reap, then this child was prevented by ptrace and we must
367 * reap it now, in that case we must also wake up sub-threads sleeping in
370 static bool __ptrace_detach(struct task_struct *tracer, struct task_struct *p)
374 if (p->exit_state == EXIT_ZOMBIE) {
375 if (!task_detached(p) && thread_group_empty(p)) {
376 if (!same_thread_group(p->real_parent, tracer))
377 do_notify_parent(p, p->exit_signal);
378 else if (ignoring_children(tracer->sighand)) {
379 __wake_up_parent(p, tracer);
383 if (task_detached(p)) {
384 /* Mark it as in the process of being reaped. */
385 p->exit_state = EXIT_DEAD;
393 static int ptrace_detach(struct task_struct *child, unsigned int data)
397 if (!valid_signal(data))
400 /* Architecture-specific hardware disable .. */
401 ptrace_disable(child);
402 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
404 write_lock_irq(&tasklist_lock);
406 * This child can be already killed. Make sure de_thread() or
407 * our sub-thread doing do_wait() didn't do release_task() yet.
410 child->exit_code = data;
411 dead = __ptrace_detach(current, child);
413 write_unlock_irq(&tasklist_lock);
422 * Detach all tasks we were using ptrace on. Called with tasklist held
423 * for writing, and returns with it held too. But note it can release
424 * and reacquire the lock.
426 void exit_ptrace(struct task_struct *tracer)
427 __releases(&tasklist_lock)
428 __acquires(&tasklist_lock)
430 struct task_struct *p, *n;
431 LIST_HEAD(ptrace_dead);
433 if (likely(list_empty(&tracer->ptraced)))
436 list_for_each_entry_safe(p, n, &tracer->ptraced, ptrace_entry) {
437 if (__ptrace_detach(tracer, p))
438 list_add(&p->ptrace_entry, &ptrace_dead);
441 write_unlock_irq(&tasklist_lock);
442 BUG_ON(!list_empty(&tracer->ptraced));
444 list_for_each_entry_safe(p, n, &ptrace_dead, ptrace_entry) {
445 list_del_init(&p->ptrace_entry);
449 write_lock_irq(&tasklist_lock);
452 int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len)
458 int this_len, retval;
460 this_len = (len > sizeof(buf)) ? sizeof(buf) : len;
461 retval = access_process_vm(tsk, src, buf, this_len, 0);
467 if (copy_to_user(dst, buf, retval))
477 int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len)
483 int this_len, retval;
485 this_len = (len > sizeof(buf)) ? sizeof(buf) : len;
486 if (copy_from_user(buf, src, this_len))
488 retval = access_process_vm(tsk, dst, buf, this_len, 1);
502 static int ptrace_setoptions(struct task_struct *child, unsigned long data)
504 child->ptrace &= ~PT_TRACE_MASK;
506 if (data & PTRACE_O_TRACESYSGOOD)
507 child->ptrace |= PT_TRACESYSGOOD;
509 if (data & PTRACE_O_TRACEFORK)
510 child->ptrace |= PT_TRACE_FORK;
512 if (data & PTRACE_O_TRACEVFORK)
513 child->ptrace |= PT_TRACE_VFORK;
515 if (data & PTRACE_O_TRACECLONE)
516 child->ptrace |= PT_TRACE_CLONE;
518 if (data & PTRACE_O_TRACEEXEC)
519 child->ptrace |= PT_TRACE_EXEC;
521 if (data & PTRACE_O_TRACEVFORKDONE)
522 child->ptrace |= PT_TRACE_VFORK_DONE;
524 if (data & PTRACE_O_TRACEEXIT)
525 child->ptrace |= PT_TRACE_EXIT;
527 return (data & ~PTRACE_O_MASK) ? -EINVAL : 0;
530 static int ptrace_getsiginfo(struct task_struct *child, siginfo_t *info)
535 if (lock_task_sighand(child, &flags)) {
537 if (likely(child->last_siginfo != NULL)) {
538 *info = *child->last_siginfo;
541 unlock_task_sighand(child, &flags);
546 static int ptrace_setsiginfo(struct task_struct *child, const siginfo_t *info)
551 if (lock_task_sighand(child, &flags)) {
553 if (likely(child->last_siginfo != NULL)) {
554 *child->last_siginfo = *info;
557 unlock_task_sighand(child, &flags);
563 #ifdef PTRACE_SINGLESTEP
564 #define is_singlestep(request) ((request) == PTRACE_SINGLESTEP)
566 #define is_singlestep(request) 0
569 #ifdef PTRACE_SINGLEBLOCK
570 #define is_singleblock(request) ((request) == PTRACE_SINGLEBLOCK)
572 #define is_singleblock(request) 0
576 #define is_sysemu_singlestep(request) ((request) == PTRACE_SYSEMU_SINGLESTEP)
578 #define is_sysemu_singlestep(request) 0
581 static int ptrace_resume(struct task_struct *child, long request,
584 if (!valid_signal(data))
587 if (request == PTRACE_SYSCALL)
588 set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
590 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
592 #ifdef TIF_SYSCALL_EMU
593 if (request == PTRACE_SYSEMU || request == PTRACE_SYSEMU_SINGLESTEP)
594 set_tsk_thread_flag(child, TIF_SYSCALL_EMU);
596 clear_tsk_thread_flag(child, TIF_SYSCALL_EMU);
599 if (is_singleblock(request)) {
600 if (unlikely(!arch_has_block_step()))
602 user_enable_block_step(child);
603 } else if (is_singlestep(request) || is_sysemu_singlestep(request)) {
604 if (unlikely(!arch_has_single_step()))
606 user_enable_single_step(child);
608 user_disable_single_step(child);
611 child->exit_code = data;
612 wake_up_state(child, __TASK_TRACED);
617 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
619 static const struct user_regset *
620 find_regset(const struct user_regset_view *view, unsigned int type)
622 const struct user_regset *regset;
625 for (n = 0; n < view->n; ++n) {
626 regset = view->regsets + n;
627 if (regset->core_note_type == type)
634 static int ptrace_regset(struct task_struct *task, int req, unsigned int type,
637 const struct user_regset_view *view = task_user_regset_view(task);
638 const struct user_regset *regset = find_regset(view, type);
641 if (!regset || (kiov->iov_len % regset->size) != 0)
644 regset_no = regset - view->regsets;
645 kiov->iov_len = min(kiov->iov_len,
646 (__kernel_size_t) (regset->n * regset->size));
648 if (req == PTRACE_GETREGSET)
649 return copy_regset_to_user(task, view, regset_no, 0,
650 kiov->iov_len, kiov->iov_base);
652 return copy_regset_from_user(task, view, regset_no, 0,
653 kiov->iov_len, kiov->iov_base);
658 int ptrace_request(struct task_struct *child, long request,
659 unsigned long addr, unsigned long data)
663 void __user *datavp = (void __user *) data;
664 unsigned long __user *datalp = datavp;
667 case PTRACE_PEEKTEXT:
668 case PTRACE_PEEKDATA:
669 return generic_ptrace_peekdata(child, addr, data);
670 case PTRACE_POKETEXT:
671 case PTRACE_POKEDATA:
672 return generic_ptrace_pokedata(child, addr, data);
674 #ifdef PTRACE_OLDSETOPTIONS
675 case PTRACE_OLDSETOPTIONS:
677 case PTRACE_SETOPTIONS:
678 ret = ptrace_setoptions(child, data);
680 case PTRACE_GETEVENTMSG:
681 ret = put_user(child->ptrace_message, datalp);
684 case PTRACE_GETSIGINFO:
685 ret = ptrace_getsiginfo(child, &siginfo);
687 ret = copy_siginfo_to_user(datavp, &siginfo);
690 case PTRACE_SETSIGINFO:
691 if (copy_from_user(&siginfo, datavp, sizeof siginfo))
694 ret = ptrace_setsiginfo(child, &siginfo);
697 case PTRACE_DETACH: /* detach a process that was attached. */
698 ret = ptrace_detach(child, data);
701 #ifdef CONFIG_BINFMT_ELF_FDPIC
702 case PTRACE_GETFDPIC: {
703 struct mm_struct *mm = get_task_mm(child);
704 unsigned long tmp = 0;
711 case PTRACE_GETFDPIC_EXEC:
712 tmp = mm->context.exec_fdpic_loadmap;
714 case PTRACE_GETFDPIC_INTERP:
715 tmp = mm->context.interp_fdpic_loadmap;
722 ret = put_user(tmp, datalp);
727 #ifdef PTRACE_SINGLESTEP
728 case PTRACE_SINGLESTEP:
730 #ifdef PTRACE_SINGLEBLOCK
731 case PTRACE_SINGLEBLOCK:
735 case PTRACE_SYSEMU_SINGLESTEP:
739 return ptrace_resume(child, request, data);
742 if (child->exit_state) /* already dead */
744 return ptrace_resume(child, request, SIGKILL);
746 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
747 case PTRACE_GETREGSET:
748 case PTRACE_SETREGSET:
751 struct iovec __user *uiov = datavp;
753 if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov)))
756 if (__get_user(kiov.iov_base, &uiov->iov_base) ||
757 __get_user(kiov.iov_len, &uiov->iov_len))
760 ret = ptrace_regset(child, request, addr, &kiov);
762 ret = __put_user(kiov.iov_len, &uiov->iov_len);
773 static struct task_struct *ptrace_get_task_struct(pid_t pid)
775 struct task_struct *child;
778 child = find_task_by_vpid(pid);
780 get_task_struct(child);
784 return ERR_PTR(-ESRCH);
788 #ifndef arch_ptrace_attach
789 #define arch_ptrace_attach(child) do { } while (0)
792 SYSCALL_DEFINE4(ptrace, long, request, long, pid, unsigned long, addr,
795 struct task_struct *child;
798 if (request == PTRACE_TRACEME) {
799 ret = ptrace_traceme();
801 arch_ptrace_attach(current);
805 child = ptrace_get_task_struct(pid);
807 ret = PTR_ERR(child);
811 if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) {
812 ret = ptrace_attach(child, request, data);
814 * Some architectures need to do book-keeping after
818 arch_ptrace_attach(child);
819 goto out_put_task_struct;
822 ret = ptrace_check_attach(child, request == PTRACE_KILL);
824 goto out_put_task_struct;
826 ret = arch_ptrace(child, request, addr, data);
829 put_task_struct(child);
834 int generic_ptrace_peekdata(struct task_struct *tsk, unsigned long addr,
840 copied = access_process_vm(tsk, addr, &tmp, sizeof(tmp), 0);
841 if (copied != sizeof(tmp))
843 return put_user(tmp, (unsigned long __user *)data);
846 int generic_ptrace_pokedata(struct task_struct *tsk, unsigned long addr,
851 copied = access_process_vm(tsk, addr, &data, sizeof(data), 1);
852 return (copied == sizeof(data)) ? 0 : -EIO;
855 #if defined CONFIG_COMPAT
856 #include <linux/compat.h>
858 int compat_ptrace_request(struct task_struct *child, compat_long_t request,
859 compat_ulong_t addr, compat_ulong_t data)
861 compat_ulong_t __user *datap = compat_ptr(data);
867 case PTRACE_PEEKTEXT:
868 case PTRACE_PEEKDATA:
869 ret = access_process_vm(child, addr, &word, sizeof(word), 0);
870 if (ret != sizeof(word))
873 ret = put_user(word, datap);
876 case PTRACE_POKETEXT:
877 case PTRACE_POKEDATA:
878 ret = access_process_vm(child, addr, &data, sizeof(data), 1);
879 ret = (ret != sizeof(data) ? -EIO : 0);
882 case PTRACE_GETEVENTMSG:
883 ret = put_user((compat_ulong_t) child->ptrace_message, datap);
886 case PTRACE_GETSIGINFO:
887 ret = ptrace_getsiginfo(child, &siginfo);
889 ret = copy_siginfo_to_user32(
890 (struct compat_siginfo __user *) datap,
894 case PTRACE_SETSIGINFO:
895 memset(&siginfo, 0, sizeof siginfo);
896 if (copy_siginfo_from_user32(
897 &siginfo, (struct compat_siginfo __user *) datap))
900 ret = ptrace_setsiginfo(child, &siginfo);
902 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
903 case PTRACE_GETREGSET:
904 case PTRACE_SETREGSET:
907 struct compat_iovec __user *uiov =
908 (struct compat_iovec __user *) datap;
912 if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov)))
915 if (__get_user(ptr, &uiov->iov_base) ||
916 __get_user(len, &uiov->iov_len))
919 kiov.iov_base = compat_ptr(ptr);
922 ret = ptrace_regset(child, request, addr, &kiov);
924 ret = __put_user(kiov.iov_len, &uiov->iov_len);
930 ret = ptrace_request(child, request, addr, data);
936 asmlinkage long compat_sys_ptrace(compat_long_t request, compat_long_t pid,
937 compat_long_t addr, compat_long_t data)
939 struct task_struct *child;
942 if (request == PTRACE_TRACEME) {
943 ret = ptrace_traceme();
947 child = ptrace_get_task_struct(pid);
949 ret = PTR_ERR(child);
953 if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) {
954 ret = ptrace_attach(child, request, data);
956 * Some architectures need to do book-keeping after
960 arch_ptrace_attach(child);
961 goto out_put_task_struct;
964 ret = ptrace_check_attach(child, request == PTRACE_KILL);
966 ret = compat_arch_ptrace(child, request, addr, data);
969 put_task_struct(child);
973 #endif /* CONFIG_COMPAT */
975 #ifdef CONFIG_HAVE_HW_BREAKPOINT
976 int ptrace_get_breakpoints(struct task_struct *tsk)
978 if (atomic_inc_not_zero(&tsk->ptrace_bp_refcnt))
984 void ptrace_put_breakpoints(struct task_struct *tsk)
986 if (atomic_dec_and_test(&tsk->ptrace_bp_refcnt))
987 flush_ptrace_hw_breakpoint(tsk);
989 #endif /* CONFIG_HAVE_HW_BREAKPOINT */