1 // SPDX-License-Identifier: GPL-2.0-only
3 * linux/kernel/ptrace.c
5 * (C) Copyright 1999 Linus Torvalds
7 * Common interfaces for "ptrace()" which we do not want
8 * to continually duplicate across every architecture.
11 #include <linux/capability.h>
12 #include <linux/export.h>
13 #include <linux/sched.h>
14 #include <linux/sched/mm.h>
15 #include <linux/sched/coredump.h>
16 #include <linux/sched/task.h>
17 #include <linux/errno.h>
19 #include <linux/highmem.h>
20 #include <linux/pagemap.h>
21 #include <linux/ptrace.h>
22 #include <linux/security.h>
23 #include <linux/signal.h>
24 #include <linux/uio.h>
25 #include <linux/audit.h>
26 #include <linux/pid_namespace.h>
27 #include <linux/syscalls.h>
28 #include <linux/uaccess.h>
29 #include <linux/regset.h>
30 #include <linux/hw_breakpoint.h>
31 #include <linux/cn_proc.h>
32 #include <linux/compat.h>
33 #include <linux/sched/signal.h>
36 * Access another process' address space via ptrace.
37 * Source/target buffer must be kernel space,
38 * Do not walk the page table directly, use get_user_pages
40 int ptrace_access_vm(struct task_struct
*tsk
, unsigned long addr
,
41 void *buf
, int len
, unsigned int gup_flags
)
46 mm
= get_task_mm(tsk
);
51 (current
!= tsk
->parent
) ||
52 ((get_dumpable(mm
) != SUID_DUMP_USER
) &&
53 !ptracer_capable(tsk
, mm
->user_ns
))) {
58 ret
= __access_remote_vm(tsk
, mm
, addr
, buf
, len
, gup_flags
);
65 void __ptrace_link(struct task_struct
*child
, struct task_struct
*new_parent
,
66 const struct cred
*ptracer_cred
)
68 BUG_ON(!list_empty(&child
->ptrace_entry
));
69 list_add(&child
->ptrace_entry
, &new_parent
->ptraced
);
70 child
->parent
= new_parent
;
71 child
->ptracer_cred
= get_cred(ptracer_cred
);
75 * ptrace a task: make the debugger its new parent and
76 * move it to the ptrace list.
78 * Must be called with the tasklist lock write-held.
80 static void ptrace_link(struct task_struct
*child
, struct task_struct
*new_parent
)
83 __ptrace_link(child
, new_parent
, __task_cred(new_parent
));
88 * __ptrace_unlink - unlink ptracee and restore its execution state
89 * @child: ptracee to be unlinked
91 * Remove @child from the ptrace list, move it back to the original parent,
92 * and restore the execution state so that it conforms to the group stop
95 * Unlinking can happen via two paths - explicit PTRACE_DETACH or ptracer
96 * exiting. For PTRACE_DETACH, unless the ptracee has been killed between
97 * ptrace_check_attach() and here, it's guaranteed to be in TASK_TRACED.
98 * If the ptracer is exiting, the ptracee can be in any state.
100 * After detach, the ptracee should be in a state which conforms to the
101 * group stop. If the group is stopped or in the process of stopping, the
102 * ptracee should be put into TASK_STOPPED; otherwise, it should be woken
103 * up from TASK_TRACED.
105 * If the ptracee is in TASK_TRACED and needs to be moved to TASK_STOPPED,
106 * it goes through TRACED -> RUNNING -> STOPPED transition which is similar
107 * to but in the opposite direction of what happens while attaching to a
108 * stopped task. However, in this direction, the intermediate RUNNING
109 * state is not hidden even from the current ptracer and if it immediately
110 * re-attaches and performs a WNOHANG wait(2), it may fail.
113 * write_lock_irq(tasklist_lock)
115 void __ptrace_unlink(struct task_struct
*child
)
117 const struct cred
*old_cred
;
118 BUG_ON(!child
->ptrace
);
120 clear_tsk_thread_flag(child
, TIF_SYSCALL_TRACE
);
122 child
->parent
= child
->real_parent
;
123 list_del_init(&child
->ptrace_entry
);
124 old_cred
= child
->ptracer_cred
;
125 child
->ptracer_cred
= NULL
;
128 spin_lock(&child
->sighand
->siglock
);
131 * Clear all pending traps and TRAPPING. TRAPPING should be
132 * cleared regardless of JOBCTL_STOP_PENDING. Do it explicitly.
134 task_clear_jobctl_pending(child
, JOBCTL_TRAP_MASK
);
135 task_clear_jobctl_trapping(child
);
138 * Reinstate JOBCTL_STOP_PENDING if group stop is in effect and
141 if (!(child
->flags
& PF_EXITING
) &&
142 (child
->signal
->flags
& SIGNAL_STOP_STOPPED
||
143 child
->signal
->group_stop_count
)) {
144 child
->jobctl
|= JOBCTL_STOP_PENDING
;
147 * This is only possible if this thread was cloned by the
148 * traced task running in the stopped group, set the signal
149 * for the future reports.
150 * FIXME: we should change ptrace_init_task() to handle this
153 if (!(child
->jobctl
& JOBCTL_STOP_SIGMASK
))
154 child
->jobctl
|= SIGSTOP
;
158 * If transition to TASK_STOPPED is pending or in TASK_TRACED, kick
159 * @child in the butt. Note that @resume should be used iff @child
160 * is in TASK_TRACED; otherwise, we might unduly disrupt
161 * TASK_KILLABLE sleeps.
163 if (child
->jobctl
& JOBCTL_STOP_PENDING
|| task_is_traced(child
))
164 ptrace_signal_wake_up(child
, true);
166 spin_unlock(&child
->sighand
->siglock
);
169 /* Ensure that nothing can wake it up, even SIGKILL */
170 static bool ptrace_freeze_traced(struct task_struct
*task
)
174 /* Lockless, nobody but us can set this flag */
175 if (task
->jobctl
& JOBCTL_LISTENING
)
178 spin_lock_irq(&task
->sighand
->siglock
);
179 if (task_is_traced(task
) && !__fatal_signal_pending(task
)) {
180 task
->state
= __TASK_TRACED
;
183 spin_unlock_irq(&task
->sighand
->siglock
);
188 static void ptrace_unfreeze_traced(struct task_struct
*task
)
190 if (task
->state
!= __TASK_TRACED
)
193 WARN_ON(!task
->ptrace
|| task
->parent
!= current
);
196 * PTRACE_LISTEN can allow ptrace_trap_notify to wake us up remotely.
197 * Recheck state under the lock to close this race.
199 spin_lock_irq(&task
->sighand
->siglock
);
200 if (task
->state
== __TASK_TRACED
) {
201 if (__fatal_signal_pending(task
))
202 wake_up_state(task
, __TASK_TRACED
);
204 task
->state
= TASK_TRACED
;
206 spin_unlock_irq(&task
->sighand
->siglock
);
210 * ptrace_check_attach - check whether ptracee is ready for ptrace operation
211 * @child: ptracee to check for
212 * @ignore_state: don't check whether @child is currently %TASK_TRACED
214 * Check whether @child is being ptraced by %current and ready for further
215 * ptrace operations. If @ignore_state is %false, @child also should be in
216 * %TASK_TRACED state and on return the child is guaranteed to be traced
217 * and not executing. If @ignore_state is %true, @child can be in any
221 * Grabs and releases tasklist_lock and @child->sighand->siglock.
224 * 0 on success, -ESRCH if %child is not ready.
226 static int ptrace_check_attach(struct task_struct
*child
, bool ignore_state
)
231 * We take the read lock around doing both checks to close a
232 * possible race where someone else was tracing our child and
233 * detached between these two checks. After this locked check,
234 * we are sure that this is our traced child and that can only
235 * be changed by us so it's not changing right after this.
237 read_lock(&tasklist_lock
);
238 if (child
->ptrace
&& child
->parent
== current
) {
239 WARN_ON(child
->state
== __TASK_TRACED
);
241 * child->sighand can't be NULL, release_task()
242 * does ptrace_unlink() before __exit_signal().
244 if (ignore_state
|| ptrace_freeze_traced(child
))
247 read_unlock(&tasklist_lock
);
249 if (!ret
&& !ignore_state
) {
250 if (!wait_task_inactive(child
, __TASK_TRACED
)) {
252 * This can only happen if may_ptrace_stop() fails and
253 * ptrace_stop() changes ->state back to TASK_RUNNING,
254 * so we should not worry about leaking __TASK_TRACED.
256 WARN_ON(child
->state
== __TASK_TRACED
);
264 static int ptrace_has_cap(struct user_namespace
*ns
, unsigned int mode
)
266 if (mode
& PTRACE_MODE_NOAUDIT
)
267 return has_ns_capability_noaudit(current
, ns
, CAP_SYS_PTRACE
);
269 return has_ns_capability(current
, ns
, CAP_SYS_PTRACE
);
272 /* Returns 0 on success, -errno on denial. */
273 static int __ptrace_may_access(struct task_struct
*task
, unsigned int mode
)
275 const struct cred
*cred
= current_cred(), *tcred
;
276 struct mm_struct
*mm
;
280 if (!(mode
& PTRACE_MODE_FSCREDS
) == !(mode
& PTRACE_MODE_REALCREDS
)) {
281 WARN(1, "denying ptrace access check without PTRACE_MODE_*CREDS\n");
285 /* May we inspect the given task?
286 * This check is used both for attaching with ptrace
287 * and for allowing access to sensitive information in /proc.
289 * ptrace_attach denies several cases that /proc allows
290 * because setting up the necessary parent/child relationship
291 * or halting the specified task is impossible.
294 /* Don't let security modules deny introspection */
295 if (same_thread_group(task
, current
))
298 if (mode
& PTRACE_MODE_FSCREDS
) {
299 caller_uid
= cred
->fsuid
;
300 caller_gid
= cred
->fsgid
;
303 * Using the euid would make more sense here, but something
304 * in userland might rely on the old behavior, and this
305 * shouldn't be a security problem since
306 * PTRACE_MODE_REALCREDS implies that the caller explicitly
307 * used a syscall that requests access to another process
308 * (and not a filesystem syscall to procfs).
310 caller_uid
= cred
->uid
;
311 caller_gid
= cred
->gid
;
313 tcred
= __task_cred(task
);
314 if (uid_eq(caller_uid
, tcred
->euid
) &&
315 uid_eq(caller_uid
, tcred
->suid
) &&
316 uid_eq(caller_uid
, tcred
->uid
) &&
317 gid_eq(caller_gid
, tcred
->egid
) &&
318 gid_eq(caller_gid
, tcred
->sgid
) &&
319 gid_eq(caller_gid
, tcred
->gid
))
321 if (ptrace_has_cap(tcred
->user_ns
, mode
))
329 ((get_dumpable(mm
) != SUID_DUMP_USER
) &&
330 !ptrace_has_cap(mm
->user_ns
, mode
)))
333 return security_ptrace_access_check(task
, mode
);
336 bool ptrace_may_access(struct task_struct
*task
, unsigned int mode
)
340 err
= __ptrace_may_access(task
, mode
);
345 static int ptrace_attach(struct task_struct
*task
, long request
,
349 bool seize
= (request
== PTRACE_SEIZE
);
356 if (flags
& ~(unsigned long)PTRACE_O_MASK
)
358 flags
= PT_PTRACED
| PT_SEIZED
| (flags
<< PT_OPT_FLAG_SHIFT
);
366 if (unlikely(task
->flags
& PF_KTHREAD
))
368 if (same_thread_group(task
, current
))
372 * Protect exec's credential calculations against our interference;
373 * SUID, SGID and LSM creds get determined differently
376 retval
= -ERESTARTNOINTR
;
377 if (mutex_lock_interruptible(&task
->signal
->cred_guard_mutex
))
381 retval
= __ptrace_may_access(task
, PTRACE_MODE_ATTACH_REALCREDS
);
386 write_lock_irq(&tasklist_lock
);
388 if (unlikely(task
->exit_state
))
389 goto unlock_tasklist
;
391 goto unlock_tasklist
;
395 task
->ptrace
= flags
;
397 ptrace_link(task
, current
);
399 /* SEIZE doesn't trap tracee on attach */
401 send_sig_info(SIGSTOP
, SEND_SIG_PRIV
, task
);
403 spin_lock(&task
->sighand
->siglock
);
406 * If the task is already STOPPED, set JOBCTL_TRAP_STOP and
407 * TRAPPING, and kick it so that it transits to TRACED. TRAPPING
408 * will be cleared if the child completes the transition or any
409 * event which clears the group stop states happens. We'll wait
410 * for the transition to complete before returning from this
413 * This hides STOPPED -> RUNNING -> TRACED transition from the
414 * attaching thread but a different thread in the same group can
415 * still observe the transient RUNNING state. IOW, if another
416 * thread's WNOHANG wait(2) on the stopped tracee races against
417 * ATTACH, the wait(2) may fail due to the transient RUNNING.
419 * The following task_is_stopped() test is safe as both transitions
420 * in and out of STOPPED are protected by siglock.
422 if (task_is_stopped(task
) &&
423 task_set_jobctl_pending(task
, JOBCTL_TRAP_STOP
| JOBCTL_TRAPPING
))
424 signal_wake_up_state(task
, __TASK_STOPPED
);
426 spin_unlock(&task
->sighand
->siglock
);
430 write_unlock_irq(&tasklist_lock
);
432 mutex_unlock(&task
->signal
->cred_guard_mutex
);
436 * We do not bother to change retval or clear JOBCTL_TRAPPING
437 * if wait_on_bit() was interrupted by SIGKILL. The tracer will
438 * not return to user-mode, it will exit and clear this bit in
439 * __ptrace_unlink() if it wasn't already cleared by the tracee;
440 * and until then nobody can ptrace this task.
442 wait_on_bit(&task
->jobctl
, JOBCTL_TRAPPING_BIT
, TASK_KILLABLE
);
443 proc_ptrace_connector(task
, PTRACE_ATTACH
);
450 * ptrace_traceme -- helper for PTRACE_TRACEME
452 * Performs checks and sets PT_PTRACED.
453 * Should be used by all ptrace implementations for PTRACE_TRACEME.
455 static int ptrace_traceme(void)
459 write_lock_irq(&tasklist_lock
);
460 /* Are we already being traced? */
461 if (!current
->ptrace
) {
462 ret
= security_ptrace_traceme(current
->parent
);
464 * Check PF_EXITING to ensure ->real_parent has not passed
465 * exit_ptrace(). Otherwise we don't report the error but
466 * pretend ->real_parent untraces us right after return.
468 if (!ret
&& !(current
->real_parent
->flags
& PF_EXITING
)) {
469 current
->ptrace
= PT_PTRACED
;
470 ptrace_link(current
, current
->real_parent
);
473 write_unlock_irq(&tasklist_lock
);
479 * Called with irqs disabled, returns true if childs should reap themselves.
481 static int ignoring_children(struct sighand_struct
*sigh
)
484 spin_lock(&sigh
->siglock
);
485 ret
= (sigh
->action
[SIGCHLD
-1].sa
.sa_handler
== SIG_IGN
) ||
486 (sigh
->action
[SIGCHLD
-1].sa
.sa_flags
& SA_NOCLDWAIT
);
487 spin_unlock(&sigh
->siglock
);
492 * Called with tasklist_lock held for writing.
493 * Unlink a traced task, and clean it up if it was a traced zombie.
494 * Return true if it needs to be reaped with release_task().
495 * (We can't call release_task() here because we already hold tasklist_lock.)
497 * If it's a zombie, our attachedness prevented normal parent notification
498 * or self-reaping. Do notification now if it would have happened earlier.
499 * If it should reap itself, return true.
501 * If it's our own child, there is no notification to do. But if our normal
502 * children self-reap, then this child was prevented by ptrace and we must
503 * reap it now, in that case we must also wake up sub-threads sleeping in
506 static bool __ptrace_detach(struct task_struct
*tracer
, struct task_struct
*p
)
512 if (p
->exit_state
!= EXIT_ZOMBIE
)
515 dead
= !thread_group_leader(p
);
517 if (!dead
&& thread_group_empty(p
)) {
518 if (!same_thread_group(p
->real_parent
, tracer
))
519 dead
= do_notify_parent(p
, p
->exit_signal
);
520 else if (ignoring_children(tracer
->sighand
)) {
521 __wake_up_parent(p
, tracer
);
525 /* Mark it as in the process of being reaped. */
527 p
->exit_state
= EXIT_DEAD
;
531 static int ptrace_detach(struct task_struct
*child
, unsigned int data
)
533 if (!valid_signal(data
))
536 /* Architecture-specific hardware disable .. */
537 ptrace_disable(child
);
539 write_lock_irq(&tasklist_lock
);
541 * We rely on ptrace_freeze_traced(). It can't be killed and
542 * untraced by another thread, it can't be a zombie.
544 WARN_ON(!child
->ptrace
|| child
->exit_state
);
546 * tasklist_lock avoids the race with wait_task_stopped(), see
547 * the comment in ptrace_resume().
549 child
->exit_code
= data
;
550 __ptrace_detach(current
, child
);
551 write_unlock_irq(&tasklist_lock
);
553 proc_ptrace_connector(child
, PTRACE_DETACH
);
559 * Detach all tasks we were using ptrace on. Called with tasklist held
562 void exit_ptrace(struct task_struct
*tracer
, struct list_head
*dead
)
564 struct task_struct
*p
, *n
;
566 list_for_each_entry_safe(p
, n
, &tracer
->ptraced
, ptrace_entry
) {
567 if (unlikely(p
->ptrace
& PT_EXITKILL
))
568 send_sig_info(SIGKILL
, SEND_SIG_PRIV
, p
);
570 if (__ptrace_detach(tracer
, p
))
571 list_add(&p
->ptrace_entry
, dead
);
575 int ptrace_readdata(struct task_struct
*tsk
, unsigned long src
, char __user
*dst
, int len
)
581 int this_len
, retval
;
583 this_len
= (len
> sizeof(buf
)) ? sizeof(buf
) : len
;
584 retval
= ptrace_access_vm(tsk
, src
, buf
, this_len
, FOLL_FORCE
);
591 if (copy_to_user(dst
, buf
, retval
))
601 int ptrace_writedata(struct task_struct
*tsk
, char __user
*src
, unsigned long dst
, int len
)
607 int this_len
, retval
;
609 this_len
= (len
> sizeof(buf
)) ? sizeof(buf
) : len
;
610 if (copy_from_user(buf
, src
, this_len
))
612 retval
= ptrace_access_vm(tsk
, dst
, buf
, this_len
,
613 FOLL_FORCE
| FOLL_WRITE
);
627 static int ptrace_setoptions(struct task_struct
*child
, unsigned long data
)
631 if (data
& ~(unsigned long)PTRACE_O_MASK
)
634 if (unlikely(data
& PTRACE_O_SUSPEND_SECCOMP
)) {
635 if (!IS_ENABLED(CONFIG_CHECKPOINT_RESTORE
) ||
636 !IS_ENABLED(CONFIG_SECCOMP
))
639 if (!capable(CAP_SYS_ADMIN
))
642 if (seccomp_mode(¤t
->seccomp
) != SECCOMP_MODE_DISABLED
||
643 current
->ptrace
& PT_SUSPEND_SECCOMP
)
647 /* Avoid intermediate state when all opts are cleared */
648 flags
= child
->ptrace
;
649 flags
&= ~(PTRACE_O_MASK
<< PT_OPT_FLAG_SHIFT
);
650 flags
|= (data
<< PT_OPT_FLAG_SHIFT
);
651 child
->ptrace
= flags
;
656 static int ptrace_getsiginfo(struct task_struct
*child
, kernel_siginfo_t
*info
)
661 if (lock_task_sighand(child
, &flags
)) {
663 if (likely(child
->last_siginfo
!= NULL
)) {
664 copy_siginfo(info
, child
->last_siginfo
);
667 unlock_task_sighand(child
, &flags
);
672 static int ptrace_setsiginfo(struct task_struct
*child
, const kernel_siginfo_t
*info
)
677 if (lock_task_sighand(child
, &flags
)) {
679 if (likely(child
->last_siginfo
!= NULL
)) {
680 copy_siginfo(child
->last_siginfo
, info
);
683 unlock_task_sighand(child
, &flags
);
688 static int ptrace_peek_siginfo(struct task_struct
*child
,
692 struct ptrace_peeksiginfo_args arg
;
693 struct sigpending
*pending
;
697 ret
= copy_from_user(&arg
, (void __user
*) addr
,
698 sizeof(struct ptrace_peeksiginfo_args
));
702 if (arg
.flags
& ~PTRACE_PEEKSIGINFO_SHARED
)
703 return -EINVAL
; /* unknown flags */
708 if (arg
.flags
& PTRACE_PEEKSIGINFO_SHARED
)
709 pending
= &child
->signal
->shared_pending
;
711 pending
= &child
->pending
;
713 for (i
= 0; i
< arg
.nr
; ) {
714 kernel_siginfo_t info
;
715 s32 off
= arg
.off
+ i
;
717 spin_lock_irq(&child
->sighand
->siglock
);
718 list_for_each_entry(q
, &pending
->list
, list
) {
720 copy_siginfo(&info
, &q
->info
);
724 spin_unlock_irq(&child
->sighand
->siglock
);
726 if (off
>= 0) /* beyond the end of the list */
730 if (unlikely(in_compat_syscall())) {
731 compat_siginfo_t __user
*uinfo
= compat_ptr(data
);
733 if (copy_siginfo_to_user32(uinfo
, &info
)) {
741 siginfo_t __user
*uinfo
= (siginfo_t __user
*) data
;
743 if (copy_siginfo_to_user(uinfo
, &info
)) {
749 data
+= sizeof(siginfo_t
);
752 if (signal_pending(current
))
764 #ifdef PTRACE_SINGLESTEP
765 #define is_singlestep(request) ((request) == PTRACE_SINGLESTEP)
767 #define is_singlestep(request) 0
770 #ifdef PTRACE_SINGLEBLOCK
771 #define is_singleblock(request) ((request) == PTRACE_SINGLEBLOCK)
773 #define is_singleblock(request) 0
777 #define is_sysemu_singlestep(request) ((request) == PTRACE_SYSEMU_SINGLESTEP)
779 #define is_sysemu_singlestep(request) 0
782 static int ptrace_resume(struct task_struct
*child
, long request
,
787 if (!valid_signal(data
))
790 if (request
== PTRACE_SYSCALL
)
791 set_tsk_thread_flag(child
, TIF_SYSCALL_TRACE
);
793 clear_tsk_thread_flag(child
, TIF_SYSCALL_TRACE
);
795 #ifdef TIF_SYSCALL_EMU
796 if (request
== PTRACE_SYSEMU
|| request
== PTRACE_SYSEMU_SINGLESTEP
)
797 set_tsk_thread_flag(child
, TIF_SYSCALL_EMU
);
799 clear_tsk_thread_flag(child
, TIF_SYSCALL_EMU
);
802 if (is_singleblock(request
)) {
803 if (unlikely(!arch_has_block_step()))
805 user_enable_block_step(child
);
806 } else if (is_singlestep(request
) || is_sysemu_singlestep(request
)) {
807 if (unlikely(!arch_has_single_step()))
809 user_enable_single_step(child
);
811 user_disable_single_step(child
);
815 * Change ->exit_code and ->state under siglock to avoid the race
816 * with wait_task_stopped() in between; a non-zero ->exit_code will
817 * wrongly look like another report from tracee.
819 * Note that we need siglock even if ->exit_code == data and/or this
820 * status was not reported yet, the new status must not be cleared by
821 * wait_task_stopped() after resume.
823 * If data == 0 we do not care if wait_task_stopped() reports the old
824 * status and clears the code too; this can't race with the tracee, it
825 * takes siglock after resume.
827 need_siglock
= data
&& !thread_group_empty(current
);
829 spin_lock_irq(&child
->sighand
->siglock
);
830 child
->exit_code
= data
;
831 wake_up_state(child
, __TASK_TRACED
);
833 spin_unlock_irq(&child
->sighand
->siglock
);
838 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
840 static const struct user_regset
*
841 find_regset(const struct user_regset_view
*view
, unsigned int type
)
843 const struct user_regset
*regset
;
846 for (n
= 0; n
< view
->n
; ++n
) {
847 regset
= view
->regsets
+ n
;
848 if (regset
->core_note_type
== type
)
855 static int ptrace_regset(struct task_struct
*task
, int req
, unsigned int type
,
858 const struct user_regset_view
*view
= task_user_regset_view(task
);
859 const struct user_regset
*regset
= find_regset(view
, type
);
862 if (!regset
|| (kiov
->iov_len
% regset
->size
) != 0)
865 regset_no
= regset
- view
->regsets
;
866 kiov
->iov_len
= min(kiov
->iov_len
,
867 (__kernel_size_t
) (regset
->n
* regset
->size
));
869 if (req
== PTRACE_GETREGSET
)
870 return copy_regset_to_user(task
, view
, regset_no
, 0,
871 kiov
->iov_len
, kiov
->iov_base
);
873 return copy_regset_from_user(task
, view
, regset_no
, 0,
874 kiov
->iov_len
, kiov
->iov_base
);
878 * This is declared in linux/regset.h and defined in machine-dependent
879 * code. We put the export here, near the primary machine-neutral use,
880 * to ensure no machine forgets it.
882 EXPORT_SYMBOL_GPL(task_user_regset_view
);
885 int ptrace_request(struct task_struct
*child
, long request
,
886 unsigned long addr
, unsigned long data
)
888 bool seized
= child
->ptrace
& PT_SEIZED
;
890 kernel_siginfo_t siginfo
, *si
;
891 void __user
*datavp
= (void __user
*) data
;
892 unsigned long __user
*datalp
= datavp
;
896 case PTRACE_PEEKTEXT
:
897 case PTRACE_PEEKDATA
:
898 return generic_ptrace_peekdata(child
, addr
, data
);
899 case PTRACE_POKETEXT
:
900 case PTRACE_POKEDATA
:
901 return generic_ptrace_pokedata(child
, addr
, data
);
903 #ifdef PTRACE_OLDSETOPTIONS
904 case PTRACE_OLDSETOPTIONS
:
906 case PTRACE_SETOPTIONS
:
907 ret
= ptrace_setoptions(child
, data
);
909 case PTRACE_GETEVENTMSG
:
910 ret
= put_user(child
->ptrace_message
, datalp
);
913 case PTRACE_PEEKSIGINFO
:
914 ret
= ptrace_peek_siginfo(child
, addr
, data
);
917 case PTRACE_GETSIGINFO
:
918 ret
= ptrace_getsiginfo(child
, &siginfo
);
920 ret
= copy_siginfo_to_user(datavp
, &siginfo
);
923 case PTRACE_SETSIGINFO
:
924 ret
= copy_siginfo_from_user(&siginfo
, datavp
);
926 ret
= ptrace_setsiginfo(child
, &siginfo
);
929 case PTRACE_GETSIGMASK
: {
932 if (addr
!= sizeof(sigset_t
)) {
937 if (test_tsk_restore_sigmask(child
))
938 mask
= &child
->saved_sigmask
;
940 mask
= &child
->blocked
;
942 if (copy_to_user(datavp
, mask
, sizeof(sigset_t
)))
950 case PTRACE_SETSIGMASK
: {
953 if (addr
!= sizeof(sigset_t
)) {
958 if (copy_from_user(&new_set
, datavp
, sizeof(sigset_t
))) {
963 sigdelsetmask(&new_set
, sigmask(SIGKILL
)|sigmask(SIGSTOP
));
966 * Every thread does recalc_sigpending() after resume, so
967 * retarget_shared_pending() and recalc_sigpending() are not
970 spin_lock_irq(&child
->sighand
->siglock
);
971 child
->blocked
= new_set
;
972 spin_unlock_irq(&child
->sighand
->siglock
);
974 clear_tsk_restore_sigmask(child
);
980 case PTRACE_INTERRUPT
:
982 * Stop tracee without any side-effect on signal or job
983 * control. At least one trap is guaranteed to happen
984 * after this request. If @child is already trapped, the
985 * current trap is not disturbed and another trap will
986 * happen after the current trap is ended with PTRACE_CONT.
988 * The actual trap might not be PTRACE_EVENT_STOP trap but
989 * the pending condition is cleared regardless.
991 if (unlikely(!seized
|| !lock_task_sighand(child
, &flags
)))
995 * INTERRUPT doesn't disturb existing trap sans one
996 * exception. If ptracer issued LISTEN for the current
997 * STOP, this INTERRUPT should clear LISTEN and re-trap
1000 if (likely(task_set_jobctl_pending(child
, JOBCTL_TRAP_STOP
)))
1001 ptrace_signal_wake_up(child
, child
->jobctl
& JOBCTL_LISTENING
);
1003 unlock_task_sighand(child
, &flags
);
1009 * Listen for events. Tracee must be in STOP. It's not
1010 * resumed per-se but is not considered to be in TRACED by
1011 * wait(2) or ptrace(2). If an async event (e.g. group
1012 * stop state change) happens, tracee will enter STOP trap
1013 * again. Alternatively, ptracer can issue INTERRUPT to
1014 * finish listening and re-trap tracee into STOP.
1016 if (unlikely(!seized
|| !lock_task_sighand(child
, &flags
)))
1019 si
= child
->last_siginfo
;
1020 if (likely(si
&& (si
->si_code
>> 8) == PTRACE_EVENT_STOP
)) {
1021 child
->jobctl
|= JOBCTL_LISTENING
;
1023 * If NOTIFY is set, it means event happened between
1024 * start of this trap and now. Trigger re-trap.
1026 if (child
->jobctl
& JOBCTL_TRAP_NOTIFY
)
1027 ptrace_signal_wake_up(child
, true);
1030 unlock_task_sighand(child
, &flags
);
1033 case PTRACE_DETACH
: /* detach a process that was attached. */
1034 ret
= ptrace_detach(child
, data
);
1037 #ifdef CONFIG_BINFMT_ELF_FDPIC
1038 case PTRACE_GETFDPIC
: {
1039 struct mm_struct
*mm
= get_task_mm(child
);
1040 unsigned long tmp
= 0;
1047 case PTRACE_GETFDPIC_EXEC
:
1048 tmp
= mm
->context
.exec_fdpic_loadmap
;
1050 case PTRACE_GETFDPIC_INTERP
:
1051 tmp
= mm
->context
.interp_fdpic_loadmap
;
1058 ret
= put_user(tmp
, datalp
);
1063 #ifdef PTRACE_SINGLESTEP
1064 case PTRACE_SINGLESTEP
:
1066 #ifdef PTRACE_SINGLEBLOCK
1067 case PTRACE_SINGLEBLOCK
:
1069 #ifdef PTRACE_SYSEMU
1071 case PTRACE_SYSEMU_SINGLESTEP
:
1073 case PTRACE_SYSCALL
:
1075 return ptrace_resume(child
, request
, data
);
1078 if (child
->exit_state
) /* already dead */
1080 return ptrace_resume(child
, request
, SIGKILL
);
1082 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
1083 case PTRACE_GETREGSET
:
1084 case PTRACE_SETREGSET
: {
1086 struct iovec __user
*uiov
= datavp
;
1088 if (!access_ok(uiov
, sizeof(*uiov
)))
1091 if (__get_user(kiov
.iov_base
, &uiov
->iov_base
) ||
1092 __get_user(kiov
.iov_len
, &uiov
->iov_len
))
1095 ret
= ptrace_regset(child
, request
, addr
, &kiov
);
1097 ret
= __put_user(kiov
.iov_len
, &uiov
->iov_len
);
1102 case PTRACE_SECCOMP_GET_FILTER
:
1103 ret
= seccomp_get_filter(child
, addr
, datavp
);
1106 case PTRACE_SECCOMP_GET_METADATA
:
1107 ret
= seccomp_get_metadata(child
, addr
, datavp
);
1117 #ifndef arch_ptrace_attach
1118 #define arch_ptrace_attach(child) do { } while (0)
1121 SYSCALL_DEFINE4(ptrace
, long, request
, long, pid
, unsigned long, addr
,
1122 unsigned long, data
)
1124 struct task_struct
*child
;
1127 if (request
== PTRACE_TRACEME
) {
1128 ret
= ptrace_traceme();
1130 arch_ptrace_attach(current
);
1134 child
= find_get_task_by_vpid(pid
);
1140 if (request
== PTRACE_ATTACH
|| request
== PTRACE_SEIZE
) {
1141 ret
= ptrace_attach(child
, request
, addr
, data
);
1143 * Some architectures need to do book-keeping after
1147 arch_ptrace_attach(child
);
1148 goto out_put_task_struct
;
1151 ret
= ptrace_check_attach(child
, request
== PTRACE_KILL
||
1152 request
== PTRACE_INTERRUPT
);
1154 goto out_put_task_struct
;
1156 ret
= arch_ptrace(child
, request
, addr
, data
);
1157 if (ret
|| request
!= PTRACE_DETACH
)
1158 ptrace_unfreeze_traced(child
);
1160 out_put_task_struct
:
1161 put_task_struct(child
);
1166 int generic_ptrace_peekdata(struct task_struct
*tsk
, unsigned long addr
,
1172 copied
= ptrace_access_vm(tsk
, addr
, &tmp
, sizeof(tmp
), FOLL_FORCE
);
1173 if (copied
!= sizeof(tmp
))
1175 return put_user(tmp
, (unsigned long __user
*)data
);
1178 int generic_ptrace_pokedata(struct task_struct
*tsk
, unsigned long addr
,
1183 copied
= ptrace_access_vm(tsk
, addr
, &data
, sizeof(data
),
1184 FOLL_FORCE
| FOLL_WRITE
);
1185 return (copied
== sizeof(data
)) ? 0 : -EIO
;
1188 #if defined CONFIG_COMPAT
1190 int compat_ptrace_request(struct task_struct
*child
, compat_long_t request
,
1191 compat_ulong_t addr
, compat_ulong_t data
)
1193 compat_ulong_t __user
*datap
= compat_ptr(data
);
1194 compat_ulong_t word
;
1195 kernel_siginfo_t siginfo
;
1199 case PTRACE_PEEKTEXT
:
1200 case PTRACE_PEEKDATA
:
1201 ret
= ptrace_access_vm(child
, addr
, &word
, sizeof(word
),
1203 if (ret
!= sizeof(word
))
1206 ret
= put_user(word
, datap
);
1209 case PTRACE_POKETEXT
:
1210 case PTRACE_POKEDATA
:
1211 ret
= ptrace_access_vm(child
, addr
, &data
, sizeof(data
),
1212 FOLL_FORCE
| FOLL_WRITE
);
1213 ret
= (ret
!= sizeof(data
) ? -EIO
: 0);
1216 case PTRACE_GETEVENTMSG
:
1217 ret
= put_user((compat_ulong_t
) child
->ptrace_message
, datap
);
1220 case PTRACE_GETSIGINFO
:
1221 ret
= ptrace_getsiginfo(child
, &siginfo
);
1223 ret
= copy_siginfo_to_user32(
1224 (struct compat_siginfo __user
*) datap
,
1228 case PTRACE_SETSIGINFO
:
1229 ret
= copy_siginfo_from_user32(
1230 &siginfo
, (struct compat_siginfo __user
*) datap
);
1232 ret
= ptrace_setsiginfo(child
, &siginfo
);
1234 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
1235 case PTRACE_GETREGSET
:
1236 case PTRACE_SETREGSET
:
1239 struct compat_iovec __user
*uiov
=
1240 (struct compat_iovec __user
*) datap
;
1244 if (!access_ok(uiov
, sizeof(*uiov
)))
1247 if (__get_user(ptr
, &uiov
->iov_base
) ||
1248 __get_user(len
, &uiov
->iov_len
))
1251 kiov
.iov_base
= compat_ptr(ptr
);
1254 ret
= ptrace_regset(child
, request
, addr
, &kiov
);
1256 ret
= __put_user(kiov
.iov_len
, &uiov
->iov_len
);
1262 ret
= ptrace_request(child
, request
, addr
, data
);
1268 COMPAT_SYSCALL_DEFINE4(ptrace
, compat_long_t
, request
, compat_long_t
, pid
,
1269 compat_long_t
, addr
, compat_long_t
, data
)
1271 struct task_struct
*child
;
1274 if (request
== PTRACE_TRACEME
) {
1275 ret
= ptrace_traceme();
1279 child
= find_get_task_by_vpid(pid
);
1285 if (request
== PTRACE_ATTACH
|| request
== PTRACE_SEIZE
) {
1286 ret
= ptrace_attach(child
, request
, addr
, data
);
1288 * Some architectures need to do book-keeping after
1292 arch_ptrace_attach(child
);
1293 goto out_put_task_struct
;
1296 ret
= ptrace_check_attach(child
, request
== PTRACE_KILL
||
1297 request
== PTRACE_INTERRUPT
);
1299 ret
= compat_arch_ptrace(child
, request
, addr
, data
);
1300 if (ret
|| request
!= PTRACE_DETACH
)
1301 ptrace_unfreeze_traced(child
);
1304 out_put_task_struct
:
1305 put_task_struct(child
);
1309 #endif /* CONFIG_COMPAT */