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>
31 static int ptrace_trapping_sleep_fn(void *flags
)
38 * ptrace a task: make the debugger its new parent and
39 * move it to the ptrace list.
41 * Must be called with the tasklist lock write-held.
43 void __ptrace_link(struct task_struct
*child
, struct task_struct
*new_parent
)
45 BUG_ON(!list_empty(&child
->ptrace_entry
));
46 list_add(&child
->ptrace_entry
, &new_parent
->ptraced
);
47 child
->parent
= new_parent
;
51 * __ptrace_unlink - unlink ptracee and restore its execution state
52 * @child: ptracee to be unlinked
54 * Remove @child from the ptrace list, move it back to the original parent,
55 * and restore the execution state so that it conforms to the group stop
58 * Unlinking can happen via two paths - explicit PTRACE_DETACH or ptracer
59 * exiting. For PTRACE_DETACH, unless the ptracee has been killed between
60 * ptrace_check_attach() and here, it's guaranteed to be in TASK_TRACED.
61 * If the ptracer is exiting, the ptracee can be in any state.
63 * After detach, the ptracee should be in a state which conforms to the
64 * group stop. If the group is stopped or in the process of stopping, the
65 * ptracee should be put into TASK_STOPPED; otherwise, it should be woken
66 * up from TASK_TRACED.
68 * If the ptracee is in TASK_TRACED and needs to be moved to TASK_STOPPED,
69 * it goes through TRACED -> RUNNING -> STOPPED transition which is similar
70 * to but in the opposite direction of what happens while attaching to a
71 * stopped task. However, in this direction, the intermediate RUNNING
72 * state is not hidden even from the current ptracer and if it immediately
73 * re-attaches and performs a WNOHANG wait(2), it may fail.
76 * write_lock_irq(tasklist_lock)
78 void __ptrace_unlink(struct task_struct
*child
)
80 BUG_ON(!child
->ptrace
);
83 child
->parent
= child
->real_parent
;
84 list_del_init(&child
->ptrace_entry
);
86 spin_lock(&child
->sighand
->siglock
);
89 * Clear all pending traps and TRAPPING. TRAPPING should be
90 * cleared regardless of JOBCTL_STOP_PENDING. Do it explicitly.
92 task_clear_jobctl_pending(child
, JOBCTL_TRAP_MASK
);
93 task_clear_jobctl_trapping(child
);
96 * Reinstate JOBCTL_STOP_PENDING if group stop is in effect and
99 if (!(child
->flags
& PF_EXITING
) &&
100 (child
->signal
->flags
& SIGNAL_STOP_STOPPED
||
101 child
->signal
->group_stop_count
)) {
102 child
->jobctl
|= JOBCTL_STOP_PENDING
;
105 * This is only possible if this thread was cloned by the
106 * traced task running in the stopped group, set the signal
107 * for the future reports.
108 * FIXME: we should change ptrace_init_task() to handle this
111 if (!(child
->jobctl
& JOBCTL_STOP_SIGMASK
))
112 child
->jobctl
|= SIGSTOP
;
116 * If transition to TASK_STOPPED is pending or in TASK_TRACED, kick
117 * @child in the butt. Note that @resume should be used iff @child
118 * is in TASK_TRACED; otherwise, we might unduly disrupt
119 * TASK_KILLABLE sleeps.
121 if (child
->jobctl
& JOBCTL_STOP_PENDING
|| task_is_traced(child
))
122 ptrace_signal_wake_up(child
, true);
124 spin_unlock(&child
->sighand
->siglock
);
127 /* Ensure that nothing can wake it up, even SIGKILL */
128 static bool ptrace_freeze_traced(struct task_struct
*task
)
132 /* Lockless, nobody but us can set this flag */
133 if (task
->jobctl
& JOBCTL_LISTENING
)
136 spin_lock_irq(&task
->sighand
->siglock
);
137 if (task_is_traced(task
) && !__fatal_signal_pending(task
)) {
138 task
->state
= __TASK_TRACED
;
141 spin_unlock_irq(&task
->sighand
->siglock
);
146 static void ptrace_unfreeze_traced(struct task_struct
*task
)
148 if (task
->state
!= __TASK_TRACED
)
151 WARN_ON(!task
->ptrace
|| task
->parent
!= current
);
154 * PTRACE_LISTEN can allow ptrace_trap_notify to wake us up remotely.
155 * Recheck state under the lock to close this race.
157 spin_lock_irq(&task
->sighand
->siglock
);
158 if (task
->state
== __TASK_TRACED
) {
159 if (__fatal_signal_pending(task
))
160 wake_up_state(task
, __TASK_TRACED
);
162 task
->state
= TASK_TRACED
;
164 spin_unlock_irq(&task
->sighand
->siglock
);
168 * ptrace_check_attach - check whether ptracee is ready for ptrace operation
169 * @child: ptracee to check for
170 * @ignore_state: don't check whether @child is currently %TASK_TRACED
172 * Check whether @child is being ptraced by %current and ready for further
173 * ptrace operations. If @ignore_state is %false, @child also should be in
174 * %TASK_TRACED state and on return the child is guaranteed to be traced
175 * and not executing. If @ignore_state is %true, @child can be in any
179 * Grabs and releases tasklist_lock and @child->sighand->siglock.
182 * 0 on success, -ESRCH if %child is not ready.
184 static int ptrace_check_attach(struct task_struct
*child
, bool ignore_state
)
189 * We take the read lock around doing both checks to close a
190 * possible race where someone else was tracing our child and
191 * detached between these two checks. After this locked check,
192 * we are sure that this is our traced child and that can only
193 * be changed by us so it's not changing right after this.
195 read_lock(&tasklist_lock
);
196 if (child
->ptrace
&& child
->parent
== current
) {
197 WARN_ON(child
->state
== __TASK_TRACED
);
199 * child->sighand can't be NULL, release_task()
200 * does ptrace_unlink() before __exit_signal().
202 if (ignore_state
|| ptrace_freeze_traced(child
))
205 read_unlock(&tasklist_lock
);
207 if (!ret
&& !ignore_state
) {
208 if (!wait_task_inactive(child
, __TASK_TRACED
)) {
210 * This can only happen if may_ptrace_stop() fails and
211 * ptrace_stop() changes ->state back to TASK_RUNNING,
212 * so we should not worry about leaking __TASK_TRACED.
214 WARN_ON(child
->state
== __TASK_TRACED
);
222 static int ptrace_has_cap(struct user_namespace
*ns
, unsigned int mode
)
224 if (mode
& PTRACE_MODE_NOAUDIT
)
225 return has_ns_capability_noaudit(current
, ns
, CAP_SYS_PTRACE
);
227 return has_ns_capability(current
, ns
, CAP_SYS_PTRACE
);
230 /* Returns 0 on success, -errno on denial. */
231 static int __ptrace_may_access(struct task_struct
*task
, unsigned int mode
)
233 const struct cred
*cred
= current_cred(), *tcred
;
238 if (!(mode
& PTRACE_MODE_FSCREDS
) == !(mode
& PTRACE_MODE_REALCREDS
)) {
239 WARN(1, "denying ptrace access check without PTRACE_MODE_*CREDS\n");
243 /* May we inspect the given task?
244 * This check is used both for attaching with ptrace
245 * and for allowing access to sensitive information in /proc.
247 * ptrace_attach denies several cases that /proc allows
248 * because setting up the necessary parent/child relationship
249 * or halting the specified task is impossible.
252 /* Don't let security modules deny introspection */
253 if (same_thread_group(task
, current
))
256 if (mode
& PTRACE_MODE_FSCREDS
) {
257 caller_uid
= cred
->fsuid
;
258 caller_gid
= cred
->fsgid
;
261 * Using the euid would make more sense here, but something
262 * in userland might rely on the old behavior, and this
263 * shouldn't be a security problem since
264 * PTRACE_MODE_REALCREDS implies that the caller explicitly
265 * used a syscall that requests access to another process
266 * (and not a filesystem syscall to procfs).
268 caller_uid
= cred
->uid
;
269 caller_gid
= cred
->gid
;
271 tcred
= __task_cred(task
);
272 if (uid_eq(caller_uid
, tcred
->euid
) &&
273 uid_eq(caller_uid
, tcred
->suid
) &&
274 uid_eq(caller_uid
, tcred
->uid
) &&
275 gid_eq(caller_gid
, tcred
->egid
) &&
276 gid_eq(caller_gid
, tcred
->sgid
) &&
277 gid_eq(caller_gid
, tcred
->gid
))
279 if (ptrace_has_cap(tcred
->user_ns
, mode
))
287 dumpable
= get_dumpable(task
->mm
);
289 if (dumpable
!= SUID_DUMP_USER
&&
290 !ptrace_has_cap(__task_cred(task
)->user_ns
, mode
)) {
296 return security_ptrace_access_check(task
, mode
);
299 bool ptrace_may_access(struct task_struct
*task
, unsigned int mode
)
303 err
= __ptrace_may_access(task
, mode
);
308 static int ptrace_attach(struct task_struct
*task
, long request
,
312 bool seize
= (request
== PTRACE_SEIZE
);
319 if (flags
& ~(unsigned long)PTRACE_O_MASK
)
321 flags
= PT_PTRACED
| PT_SEIZED
| (flags
<< PT_OPT_FLAG_SHIFT
);
329 if (unlikely(task
->flags
& PF_KTHREAD
))
331 if (same_thread_group(task
, current
))
335 * Protect exec's credential calculations against our interference;
336 * SUID, SGID and LSM creds get determined differently
339 retval
= -ERESTARTNOINTR
;
340 if (mutex_lock_interruptible(&task
->signal
->cred_guard_mutex
))
344 retval
= __ptrace_may_access(task
, PTRACE_MODE_ATTACH_REALCREDS
);
349 write_lock_irq(&tasklist_lock
);
351 if (unlikely(task
->exit_state
))
352 goto unlock_tasklist
;
354 goto unlock_tasklist
;
359 if (ns_capable(__task_cred(task
)->user_ns
, CAP_SYS_PTRACE
))
360 flags
|= PT_PTRACE_CAP
;
362 task
->ptrace
= flags
;
364 __ptrace_link(task
, current
);
366 /* SEIZE doesn't trap tracee on attach */
368 send_sig_info(SIGSTOP
, SEND_SIG_FORCED
, task
);
370 spin_lock(&task
->sighand
->siglock
);
373 * If the task is already STOPPED, set JOBCTL_TRAP_STOP and
374 * TRAPPING, and kick it so that it transits to TRACED. TRAPPING
375 * will be cleared if the child completes the transition or any
376 * event which clears the group stop states happens. We'll wait
377 * for the transition to complete before returning from this
380 * This hides STOPPED -> RUNNING -> TRACED transition from the
381 * attaching thread but a different thread in the same group can
382 * still observe the transient RUNNING state. IOW, if another
383 * thread's WNOHANG wait(2) on the stopped tracee races against
384 * ATTACH, the wait(2) may fail due to the transient RUNNING.
386 * The following task_is_stopped() test is safe as both transitions
387 * in and out of STOPPED are protected by siglock.
389 if (task_is_stopped(task
) &&
390 task_set_jobctl_pending(task
, JOBCTL_TRAP_STOP
| JOBCTL_TRAPPING
))
391 signal_wake_up_state(task
, __TASK_STOPPED
);
393 spin_unlock(&task
->sighand
->siglock
);
397 write_unlock_irq(&tasklist_lock
);
399 mutex_unlock(&task
->signal
->cred_guard_mutex
);
402 wait_on_bit(&task
->jobctl
, JOBCTL_TRAPPING_BIT
,
403 ptrace_trapping_sleep_fn
, TASK_UNINTERRUPTIBLE
);
404 proc_ptrace_connector(task
, PTRACE_ATTACH
);
411 * ptrace_traceme -- helper for PTRACE_TRACEME
413 * Performs checks and sets PT_PTRACED.
414 * Should be used by all ptrace implementations for PTRACE_TRACEME.
416 static int ptrace_traceme(void)
420 write_lock_irq(&tasklist_lock
);
421 /* Are we already being traced? */
422 if (!current
->ptrace
) {
423 ret
= security_ptrace_traceme(current
->parent
);
425 * Check PF_EXITING to ensure ->real_parent has not passed
426 * exit_ptrace(). Otherwise we don't report the error but
427 * pretend ->real_parent untraces us right after return.
429 if (!ret
&& !(current
->real_parent
->flags
& PF_EXITING
)) {
430 current
->ptrace
= PT_PTRACED
;
431 __ptrace_link(current
, current
->real_parent
);
434 write_unlock_irq(&tasklist_lock
);
440 * Called with irqs disabled, returns true if childs should reap themselves.
442 static int ignoring_children(struct sighand_struct
*sigh
)
445 spin_lock(&sigh
->siglock
);
446 ret
= (sigh
->action
[SIGCHLD
-1].sa
.sa_handler
== SIG_IGN
) ||
447 (sigh
->action
[SIGCHLD
-1].sa
.sa_flags
& SA_NOCLDWAIT
);
448 spin_unlock(&sigh
->siglock
);
453 * Called with tasklist_lock held for writing.
454 * Unlink a traced task, and clean it up if it was a traced zombie.
455 * Return true if it needs to be reaped with release_task().
456 * (We can't call release_task() here because we already hold tasklist_lock.)
458 * If it's a zombie, our attachedness prevented normal parent notification
459 * or self-reaping. Do notification now if it would have happened earlier.
460 * If it should reap itself, return true.
462 * If it's our own child, there is no notification to do. But if our normal
463 * children self-reap, then this child was prevented by ptrace and we must
464 * reap it now, in that case we must also wake up sub-threads sleeping in
467 static bool __ptrace_detach(struct task_struct
*tracer
, struct task_struct
*p
)
473 if (p
->exit_state
!= EXIT_ZOMBIE
)
476 dead
= !thread_group_leader(p
);
478 if (!dead
&& thread_group_empty(p
)) {
479 if (!same_thread_group(p
->real_parent
, tracer
))
480 dead
= do_notify_parent(p
, p
->exit_signal
);
481 else if (ignoring_children(tracer
->sighand
)) {
482 __wake_up_parent(p
, tracer
);
486 /* Mark it as in the process of being reaped. */
488 p
->exit_state
= EXIT_DEAD
;
492 static int ptrace_detach(struct task_struct
*child
, unsigned int data
)
496 if (!valid_signal(data
))
499 /* Architecture-specific hardware disable .. */
500 ptrace_disable(child
);
501 clear_tsk_thread_flag(child
, TIF_SYSCALL_TRACE
);
503 write_lock_irq(&tasklist_lock
);
505 * This child can be already killed. Make sure de_thread() or
506 * our sub-thread doing do_wait() didn't do release_task() yet.
509 child
->exit_code
= data
;
510 dead
= __ptrace_detach(current
, child
);
512 write_unlock_irq(&tasklist_lock
);
514 proc_ptrace_connector(child
, PTRACE_DETACH
);
522 * Detach all tasks we were using ptrace on. Called with tasklist held
523 * for writing, and returns with it held too. But note it can release
524 * and reacquire the lock.
526 void exit_ptrace(struct task_struct
*tracer
)
527 __releases(&tasklist_lock
)
528 __acquires(&tasklist_lock
)
530 struct task_struct
*p
, *n
;
531 LIST_HEAD(ptrace_dead
);
533 if (likely(list_empty(&tracer
->ptraced
)))
536 list_for_each_entry_safe(p
, n
, &tracer
->ptraced
, ptrace_entry
) {
537 if (unlikely(p
->ptrace
& PT_EXITKILL
))
538 send_sig_info(SIGKILL
, SEND_SIG_FORCED
, p
);
540 if (__ptrace_detach(tracer
, p
))
541 list_add(&p
->ptrace_entry
, &ptrace_dead
);
544 write_unlock_irq(&tasklist_lock
);
545 BUG_ON(!list_empty(&tracer
->ptraced
));
547 list_for_each_entry_safe(p
, n
, &ptrace_dead
, ptrace_entry
) {
548 list_del_init(&p
->ptrace_entry
);
552 write_lock_irq(&tasklist_lock
);
555 int ptrace_readdata(struct task_struct
*tsk
, unsigned long src
, char __user
*dst
, int len
)
561 int this_len
, retval
;
563 this_len
= (len
> sizeof(buf
)) ? sizeof(buf
) : len
;
564 retval
= access_process_vm(tsk
, src
, buf
, this_len
, 0);
570 if (copy_to_user(dst
, buf
, retval
))
580 int ptrace_writedata(struct task_struct
*tsk
, char __user
*src
, unsigned long dst
, int len
)
586 int this_len
, retval
;
588 this_len
= (len
> sizeof(buf
)) ? sizeof(buf
) : len
;
589 if (copy_from_user(buf
, src
, this_len
))
591 retval
= access_process_vm(tsk
, dst
, buf
, this_len
, 1);
605 static int ptrace_setoptions(struct task_struct
*child
, unsigned long data
)
609 if (data
& ~(unsigned long)PTRACE_O_MASK
)
612 /* Avoid intermediate state when all opts are cleared */
613 flags
= child
->ptrace
;
614 flags
&= ~(PTRACE_O_MASK
<< PT_OPT_FLAG_SHIFT
);
615 flags
|= (data
<< PT_OPT_FLAG_SHIFT
);
616 child
->ptrace
= flags
;
621 static int ptrace_getsiginfo(struct task_struct
*child
, siginfo_t
*info
)
626 if (lock_task_sighand(child
, &flags
)) {
628 if (likely(child
->last_siginfo
!= NULL
)) {
629 *info
= *child
->last_siginfo
;
632 unlock_task_sighand(child
, &flags
);
637 static int ptrace_setsiginfo(struct task_struct
*child
, const siginfo_t
*info
)
642 if (lock_task_sighand(child
, &flags
)) {
644 if (likely(child
->last_siginfo
!= NULL
)) {
645 *child
->last_siginfo
= *info
;
648 unlock_task_sighand(child
, &flags
);
653 static int ptrace_peek_siginfo(struct task_struct
*child
,
657 struct ptrace_peeksiginfo_args arg
;
658 struct sigpending
*pending
;
662 ret
= copy_from_user(&arg
, (void __user
*) addr
,
663 sizeof(struct ptrace_peeksiginfo_args
));
667 if (arg
.flags
& ~PTRACE_PEEKSIGINFO_SHARED
)
668 return -EINVAL
; /* unknown flags */
673 if (arg
.flags
& PTRACE_PEEKSIGINFO_SHARED
)
674 pending
= &child
->signal
->shared_pending
;
676 pending
= &child
->pending
;
678 for (i
= 0; i
< arg
.nr
; ) {
680 s32 off
= arg
.off
+ i
;
682 spin_lock_irq(&child
->sighand
->siglock
);
683 list_for_each_entry(q
, &pending
->list
, list
) {
685 copy_siginfo(&info
, &q
->info
);
689 spin_unlock_irq(&child
->sighand
->siglock
);
691 if (off
>= 0) /* beyond the end of the list */
695 if (unlikely(is_compat_task())) {
696 compat_siginfo_t __user
*uinfo
= compat_ptr(data
);
698 if (copy_siginfo_to_user32(uinfo
, &info
) ||
699 __put_user(info
.si_code
, &uinfo
->si_code
)) {
707 siginfo_t __user
*uinfo
= (siginfo_t __user
*) data
;
709 if (copy_siginfo_to_user(uinfo
, &info
) ||
710 __put_user(info
.si_code
, &uinfo
->si_code
)) {
716 data
+= sizeof(siginfo_t
);
719 if (signal_pending(current
))
731 #ifdef PTRACE_SINGLESTEP
732 #define is_singlestep(request) ((request) == PTRACE_SINGLESTEP)
734 #define is_singlestep(request) 0
737 #ifdef PTRACE_SINGLEBLOCK
738 #define is_singleblock(request) ((request) == PTRACE_SINGLEBLOCK)
740 #define is_singleblock(request) 0
744 #define is_sysemu_singlestep(request) ((request) == PTRACE_SYSEMU_SINGLESTEP)
746 #define is_sysemu_singlestep(request) 0
749 static int ptrace_resume(struct task_struct
*child
, long request
,
754 if (!valid_signal(data
))
757 if (request
== PTRACE_SYSCALL
)
758 set_tsk_thread_flag(child
, TIF_SYSCALL_TRACE
);
760 clear_tsk_thread_flag(child
, TIF_SYSCALL_TRACE
);
762 #ifdef TIF_SYSCALL_EMU
763 if (request
== PTRACE_SYSEMU
|| request
== PTRACE_SYSEMU_SINGLESTEP
)
764 set_tsk_thread_flag(child
, TIF_SYSCALL_EMU
);
766 clear_tsk_thread_flag(child
, TIF_SYSCALL_EMU
);
769 if (is_singleblock(request
)) {
770 if (unlikely(!arch_has_block_step()))
772 user_enable_block_step(child
);
773 } else if (is_singlestep(request
) || is_sysemu_singlestep(request
)) {
774 if (unlikely(!arch_has_single_step()))
776 user_enable_single_step(child
);
778 user_disable_single_step(child
);
782 * Change ->exit_code and ->state under siglock to avoid the race
783 * with wait_task_stopped() in between; a non-zero ->exit_code will
784 * wrongly look like another report from tracee.
786 * Note that we need siglock even if ->exit_code == data and/or this
787 * status was not reported yet, the new status must not be cleared by
788 * wait_task_stopped() after resume.
790 * If data == 0 we do not care if wait_task_stopped() reports the old
791 * status and clears the code too; this can't race with the tracee, it
792 * takes siglock after resume.
794 need_siglock
= data
&& !thread_group_empty(current
);
796 spin_lock_irq(&child
->sighand
->siglock
);
797 child
->exit_code
= data
;
798 wake_up_state(child
, __TASK_TRACED
);
800 spin_unlock_irq(&child
->sighand
->siglock
);
805 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
807 static const struct user_regset
*
808 find_regset(const struct user_regset_view
*view
, unsigned int type
)
810 const struct user_regset
*regset
;
813 for (n
= 0; n
< view
->n
; ++n
) {
814 regset
= view
->regsets
+ n
;
815 if (regset
->core_note_type
== type
)
822 static int ptrace_regset(struct task_struct
*task
, int req
, unsigned int type
,
825 const struct user_regset_view
*view
= task_user_regset_view(task
);
826 const struct user_regset
*regset
= find_regset(view
, type
);
829 if (!regset
|| (kiov
->iov_len
% regset
->size
) != 0)
832 regset_no
= regset
- view
->regsets
;
833 kiov
->iov_len
= min(kiov
->iov_len
,
834 (__kernel_size_t
) (regset
->n
* regset
->size
));
836 if (req
== PTRACE_GETREGSET
)
837 return copy_regset_to_user(task
, view
, regset_no
, 0,
838 kiov
->iov_len
, kiov
->iov_base
);
840 return copy_regset_from_user(task
, view
, regset_no
, 0,
841 kiov
->iov_len
, kiov
->iov_base
);
845 * This is declared in linux/regset.h and defined in machine-dependent
846 * code. We put the export here, near the primary machine-neutral use,
847 * to ensure no machine forgets it.
849 EXPORT_SYMBOL_GPL(task_user_regset_view
);
852 int ptrace_request(struct task_struct
*child
, long request
,
853 unsigned long addr
, unsigned long data
)
855 bool seized
= child
->ptrace
& PT_SEIZED
;
857 siginfo_t siginfo
, *si
;
858 void __user
*datavp
= (void __user
*) data
;
859 unsigned long __user
*datalp
= datavp
;
863 case PTRACE_PEEKTEXT
:
864 case PTRACE_PEEKDATA
:
865 return generic_ptrace_peekdata(child
, addr
, data
);
866 case PTRACE_POKETEXT
:
867 case PTRACE_POKEDATA
:
868 return generic_ptrace_pokedata(child
, addr
, data
);
870 #ifdef PTRACE_OLDSETOPTIONS
871 case PTRACE_OLDSETOPTIONS
:
873 case PTRACE_SETOPTIONS
:
874 ret
= ptrace_setoptions(child
, data
);
876 case PTRACE_GETEVENTMSG
:
877 ret
= put_user(child
->ptrace_message
, datalp
);
880 case PTRACE_PEEKSIGINFO
:
881 ret
= ptrace_peek_siginfo(child
, addr
, data
);
884 case PTRACE_GETSIGINFO
:
885 ret
= ptrace_getsiginfo(child
, &siginfo
);
887 ret
= copy_siginfo_to_user(datavp
, &siginfo
);
890 case PTRACE_SETSIGINFO
:
891 if (copy_from_user(&siginfo
, datavp
, sizeof siginfo
))
894 ret
= ptrace_setsiginfo(child
, &siginfo
);
897 case PTRACE_INTERRUPT
:
899 * Stop tracee without any side-effect on signal or job
900 * control. At least one trap is guaranteed to happen
901 * after this request. If @child is already trapped, the
902 * current trap is not disturbed and another trap will
903 * happen after the current trap is ended with PTRACE_CONT.
905 * The actual trap might not be PTRACE_EVENT_STOP trap but
906 * the pending condition is cleared regardless.
908 if (unlikely(!seized
|| !lock_task_sighand(child
, &flags
)))
912 * INTERRUPT doesn't disturb existing trap sans one
913 * exception. If ptracer issued LISTEN for the current
914 * STOP, this INTERRUPT should clear LISTEN and re-trap
917 if (likely(task_set_jobctl_pending(child
, JOBCTL_TRAP_STOP
)))
918 ptrace_signal_wake_up(child
, child
->jobctl
& JOBCTL_LISTENING
);
920 unlock_task_sighand(child
, &flags
);
926 * Listen for events. Tracee must be in STOP. It's not
927 * resumed per-se but is not considered to be in TRACED by
928 * wait(2) or ptrace(2). If an async event (e.g. group
929 * stop state change) happens, tracee will enter STOP trap
930 * again. Alternatively, ptracer can issue INTERRUPT to
931 * finish listening and re-trap tracee into STOP.
933 if (unlikely(!seized
|| !lock_task_sighand(child
, &flags
)))
936 si
= child
->last_siginfo
;
937 if (likely(si
&& (si
->si_code
>> 8) == PTRACE_EVENT_STOP
)) {
938 child
->jobctl
|= JOBCTL_LISTENING
;
940 * If NOTIFY is set, it means event happened between
941 * start of this trap and now. Trigger re-trap.
943 if (child
->jobctl
& JOBCTL_TRAP_NOTIFY
)
944 ptrace_signal_wake_up(child
, true);
947 unlock_task_sighand(child
, &flags
);
950 case PTRACE_DETACH
: /* detach a process that was attached. */
951 ret
= ptrace_detach(child
, data
);
954 #ifdef CONFIG_BINFMT_ELF_FDPIC
955 case PTRACE_GETFDPIC
: {
956 struct mm_struct
*mm
= get_task_mm(child
);
957 unsigned long tmp
= 0;
964 case PTRACE_GETFDPIC_EXEC
:
965 tmp
= mm
->context
.exec_fdpic_loadmap
;
967 case PTRACE_GETFDPIC_INTERP
:
968 tmp
= mm
->context
.interp_fdpic_loadmap
;
975 ret
= put_user(tmp
, datalp
);
980 #ifdef PTRACE_SINGLESTEP
981 case PTRACE_SINGLESTEP
:
983 #ifdef PTRACE_SINGLEBLOCK
984 case PTRACE_SINGLEBLOCK
:
988 case PTRACE_SYSEMU_SINGLESTEP
:
992 return ptrace_resume(child
, request
, data
);
995 if (child
->exit_state
) /* already dead */
997 return ptrace_resume(child
, request
, SIGKILL
);
999 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
1000 case PTRACE_GETREGSET
:
1001 case PTRACE_SETREGSET
:
1004 struct iovec __user
*uiov
= datavp
;
1006 if (!access_ok(VERIFY_WRITE
, uiov
, sizeof(*uiov
)))
1009 if (__get_user(kiov
.iov_base
, &uiov
->iov_base
) ||
1010 __get_user(kiov
.iov_len
, &uiov
->iov_len
))
1013 ret
= ptrace_regset(child
, request
, addr
, &kiov
);
1015 ret
= __put_user(kiov
.iov_len
, &uiov
->iov_len
);
1026 static struct task_struct
*ptrace_get_task_struct(pid_t pid
)
1028 struct task_struct
*child
;
1031 child
= find_task_by_vpid(pid
);
1033 get_task_struct(child
);
1037 return ERR_PTR(-ESRCH
);
1041 #ifndef arch_ptrace_attach
1042 #define arch_ptrace_attach(child) do { } while (0)
1045 SYSCALL_DEFINE4(ptrace
, long, request
, long, pid
, unsigned long, addr
,
1046 unsigned long, data
)
1048 struct task_struct
*child
;
1051 if (request
== PTRACE_TRACEME
) {
1052 ret
= ptrace_traceme();
1054 arch_ptrace_attach(current
);
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 goto out_put_task_struct
;
1080 ret
= arch_ptrace(child
, request
, addr
, data
);
1081 if (ret
|| request
!= PTRACE_DETACH
)
1082 ptrace_unfreeze_traced(child
);
1084 out_put_task_struct
:
1085 put_task_struct(child
);
1090 int generic_ptrace_peekdata(struct task_struct
*tsk
, unsigned long addr
,
1096 copied
= access_process_vm(tsk
, addr
, &tmp
, sizeof(tmp
), 0);
1097 if (copied
!= sizeof(tmp
))
1099 return put_user(tmp
, (unsigned long __user
*)data
);
1102 int generic_ptrace_pokedata(struct task_struct
*tsk
, unsigned long addr
,
1107 copied
= access_process_vm(tsk
, addr
, &data
, sizeof(data
), 1);
1108 return (copied
== sizeof(data
)) ? 0 : -EIO
;
1111 #if defined CONFIG_COMPAT
1112 #include <linux/compat.h>
1114 int compat_ptrace_request(struct task_struct
*child
, compat_long_t request
,
1115 compat_ulong_t addr
, compat_ulong_t data
)
1117 compat_ulong_t __user
*datap
= compat_ptr(data
);
1118 compat_ulong_t word
;
1123 case PTRACE_PEEKTEXT
:
1124 case PTRACE_PEEKDATA
:
1125 ret
= access_process_vm(child
, addr
, &word
, sizeof(word
), 0);
1126 if (ret
!= sizeof(word
))
1129 ret
= put_user(word
, datap
);
1132 case PTRACE_POKETEXT
:
1133 case PTRACE_POKEDATA
:
1134 ret
= access_process_vm(child
, addr
, &data
, sizeof(data
), 1);
1135 ret
= (ret
!= sizeof(data
) ? -EIO
: 0);
1138 case PTRACE_GETEVENTMSG
:
1139 ret
= put_user((compat_ulong_t
) child
->ptrace_message
, datap
);
1142 case PTRACE_GETSIGINFO
:
1143 ret
= ptrace_getsiginfo(child
, &siginfo
);
1145 ret
= copy_siginfo_to_user32(
1146 (struct compat_siginfo __user
*) datap
,
1150 case PTRACE_SETSIGINFO
:
1151 memset(&siginfo
, 0, sizeof siginfo
);
1152 if (copy_siginfo_from_user32(
1153 &siginfo
, (struct compat_siginfo __user
*) datap
))
1156 ret
= ptrace_setsiginfo(child
, &siginfo
);
1158 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
1159 case PTRACE_GETREGSET
:
1160 case PTRACE_SETREGSET
:
1163 struct compat_iovec __user
*uiov
=
1164 (struct compat_iovec __user
*) datap
;
1168 if (!access_ok(VERIFY_WRITE
, uiov
, sizeof(*uiov
)))
1171 if (__get_user(ptr
, &uiov
->iov_base
) ||
1172 __get_user(len
, &uiov
->iov_len
))
1175 kiov
.iov_base
= compat_ptr(ptr
);
1178 ret
= ptrace_regset(child
, request
, addr
, &kiov
);
1180 ret
= __put_user(kiov
.iov_len
, &uiov
->iov_len
);
1186 ret
= ptrace_request(child
, request
, addr
, data
);
1192 asmlinkage
long compat_sys_ptrace(compat_long_t request
, compat_long_t pid
,
1193 compat_long_t addr
, compat_long_t data
)
1195 struct task_struct
*child
;
1198 if (request
== PTRACE_TRACEME
) {
1199 ret
= ptrace_traceme();
1203 child
= ptrace_get_task_struct(pid
);
1204 if (IS_ERR(child
)) {
1205 ret
= PTR_ERR(child
);
1209 if (request
== PTRACE_ATTACH
|| request
== PTRACE_SEIZE
) {
1210 ret
= ptrace_attach(child
, request
, addr
, data
);
1212 * Some architectures need to do book-keeping after
1216 arch_ptrace_attach(child
);
1217 goto out_put_task_struct
;
1220 ret
= ptrace_check_attach(child
, request
== PTRACE_KILL
||
1221 request
== PTRACE_INTERRUPT
);
1223 ret
= compat_arch_ptrace(child
, request
, addr
, data
);
1224 if (ret
|| request
!= PTRACE_DETACH
)
1225 ptrace_unfreeze_traced(child
);
1228 out_put_task_struct
:
1229 put_task_struct(child
);
1233 #endif /* CONFIG_COMPAT */
1235 #ifdef CONFIG_HAVE_HW_BREAKPOINT
1236 int ptrace_get_breakpoints(struct task_struct
*tsk
)
1238 if (atomic_inc_not_zero(&tsk
->ptrace_bp_refcnt
))
1244 void ptrace_put_breakpoints(struct task_struct
*tsk
)
1246 if (atomic_dec_and_test(&tsk
->ptrace_bp_refcnt
))
1247 flush_ptrace_hw_breakpoint(tsk
);
1249 #endif /* CONFIG_HAVE_HW_BREAKPOINT */