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/sched/mm.h>
14 #include <linux/sched/coredump.h>
15 #include <linux/sched/task.h>
16 #include <linux/errno.h>
18 #include <linux/highmem.h>
19 #include <linux/pagemap.h>
20 #include <linux/ptrace.h>
21 #include <linux/security.h>
22 #include <linux/signal.h>
23 #include <linux/uio.h>
24 #include <linux/audit.h>
25 #include <linux/pid_namespace.h>
26 #include <linux/syscalls.h>
27 #include <linux/uaccess.h>
28 #include <linux/regset.h>
29 #include <linux/hw_breakpoint.h>
30 #include <linux/cn_proc.h>
31 #include <linux/compat.h>
32 #include <linux/sched/signal.h>
35 * Access another process' address space via ptrace.
36 * Source/target buffer must be kernel space,
37 * Do not walk the page table directly, use get_user_pages
39 int ptrace_access_vm(struct task_struct
*tsk
, unsigned long addr
,
40 void *buf
, int len
, unsigned int gup_flags
)
45 mm
= get_task_mm(tsk
);
50 (current
!= tsk
->parent
) ||
51 ((get_dumpable(mm
) != SUID_DUMP_USER
) &&
52 !ptracer_capable(tsk
, mm
->user_ns
))) {
57 ret
= __access_remote_vm(tsk
, mm
, addr
, buf
, len
, gup_flags
);
64 void __ptrace_link(struct task_struct
*child
, struct task_struct
*new_parent
,
65 const struct cred
*ptracer_cred
)
67 BUG_ON(!list_empty(&child
->ptrace_entry
));
68 list_add(&child
->ptrace_entry
, &new_parent
->ptraced
);
69 child
->parent
= new_parent
;
70 child
->ptracer_cred
= get_cred(ptracer_cred
);
74 * ptrace a task: make the debugger its new parent and
75 * move it to the ptrace list.
77 * Must be called with the tasklist lock write-held.
79 static void ptrace_link(struct task_struct
*child
, struct task_struct
*new_parent
)
82 __ptrace_link(child
, new_parent
, __task_cred(new_parent
));
87 * __ptrace_unlink - unlink ptracee and restore its execution state
88 * @child: ptracee to be unlinked
90 * Remove @child from the ptrace list, move it back to the original parent,
91 * and restore the execution state so that it conforms to the group stop
94 * Unlinking can happen via two paths - explicit PTRACE_DETACH or ptracer
95 * exiting. For PTRACE_DETACH, unless the ptracee has been killed between
96 * ptrace_check_attach() and here, it's guaranteed to be in TASK_TRACED.
97 * If the ptracer is exiting, the ptracee can be in any state.
99 * After detach, the ptracee should be in a state which conforms to the
100 * group stop. If the group is stopped or in the process of stopping, the
101 * ptracee should be put into TASK_STOPPED; otherwise, it should be woken
102 * up from TASK_TRACED.
104 * If the ptracee is in TASK_TRACED and needs to be moved to TASK_STOPPED,
105 * it goes through TRACED -> RUNNING -> STOPPED transition which is similar
106 * to but in the opposite direction of what happens while attaching to a
107 * stopped task. However, in this direction, the intermediate RUNNING
108 * state is not hidden even from the current ptracer and if it immediately
109 * re-attaches and performs a WNOHANG wait(2), it may fail.
112 * write_lock_irq(tasklist_lock)
114 void __ptrace_unlink(struct task_struct
*child
)
116 const struct cred
*old_cred
;
117 BUG_ON(!child
->ptrace
);
119 clear_tsk_thread_flag(child
, TIF_SYSCALL_TRACE
);
121 child
->parent
= child
->real_parent
;
122 list_del_init(&child
->ptrace_entry
);
123 old_cred
= child
->ptracer_cred
;
124 child
->ptracer_cred
= NULL
;
127 spin_lock(&child
->sighand
->siglock
);
130 * Clear all pending traps and TRAPPING. TRAPPING should be
131 * cleared regardless of JOBCTL_STOP_PENDING. Do it explicitly.
133 task_clear_jobctl_pending(child
, JOBCTL_TRAP_MASK
);
134 task_clear_jobctl_trapping(child
);
137 * Reinstate JOBCTL_STOP_PENDING if group stop is in effect and
140 if (!(child
->flags
& PF_EXITING
) &&
141 (child
->signal
->flags
& SIGNAL_STOP_STOPPED
||
142 child
->signal
->group_stop_count
)) {
143 child
->jobctl
|= JOBCTL_STOP_PENDING
;
146 * This is only possible if this thread was cloned by the
147 * traced task running in the stopped group, set the signal
148 * for the future reports.
149 * FIXME: we should change ptrace_init_task() to handle this
152 if (!(child
->jobctl
& JOBCTL_STOP_SIGMASK
))
153 child
->jobctl
|= SIGSTOP
;
157 * If transition to TASK_STOPPED is pending or in TASK_TRACED, kick
158 * @child in the butt. Note that @resume should be used iff @child
159 * is in TASK_TRACED; otherwise, we might unduly disrupt
160 * TASK_KILLABLE sleeps.
162 if (child
->jobctl
& JOBCTL_STOP_PENDING
|| task_is_traced(child
))
163 ptrace_signal_wake_up(child
, true);
165 spin_unlock(&child
->sighand
->siglock
);
168 /* Ensure that nothing can wake it up, even SIGKILL */
169 static bool ptrace_freeze_traced(struct task_struct
*task
)
173 /* Lockless, nobody but us can set this flag */
174 if (task
->jobctl
& JOBCTL_LISTENING
)
177 spin_lock_irq(&task
->sighand
->siglock
);
178 if (task_is_traced(task
) && !__fatal_signal_pending(task
)) {
179 task
->state
= __TASK_TRACED
;
182 spin_unlock_irq(&task
->sighand
->siglock
);
187 static void ptrace_unfreeze_traced(struct task_struct
*task
)
189 if (task
->state
!= __TASK_TRACED
)
192 WARN_ON(!task
->ptrace
|| task
->parent
!= current
);
195 * PTRACE_LISTEN can allow ptrace_trap_notify to wake us up remotely.
196 * Recheck state under the lock to close this race.
198 spin_lock_irq(&task
->sighand
->siglock
);
199 if (task
->state
== __TASK_TRACED
) {
200 if (__fatal_signal_pending(task
))
201 wake_up_state(task
, __TASK_TRACED
);
203 task
->state
= TASK_TRACED
;
205 spin_unlock_irq(&task
->sighand
->siglock
);
209 * ptrace_check_attach - check whether ptracee is ready for ptrace operation
210 * @child: ptracee to check for
211 * @ignore_state: don't check whether @child is currently %TASK_TRACED
213 * Check whether @child is being ptraced by %current and ready for further
214 * ptrace operations. If @ignore_state is %false, @child also should be in
215 * %TASK_TRACED state and on return the child is guaranteed to be traced
216 * and not executing. If @ignore_state is %true, @child can be in any
220 * Grabs and releases tasklist_lock and @child->sighand->siglock.
223 * 0 on success, -ESRCH if %child is not ready.
225 static int ptrace_check_attach(struct task_struct
*child
, bool ignore_state
)
230 * We take the read lock around doing both checks to close a
231 * possible race where someone else was tracing our child and
232 * detached between these two checks. After this locked check,
233 * we are sure that this is our traced child and that can only
234 * be changed by us so it's not changing right after this.
236 read_lock(&tasklist_lock
);
237 if (child
->ptrace
&& child
->parent
== current
) {
238 WARN_ON(child
->state
== __TASK_TRACED
);
240 * child->sighand can't be NULL, release_task()
241 * does ptrace_unlink() before __exit_signal().
243 if (ignore_state
|| ptrace_freeze_traced(child
))
246 read_unlock(&tasklist_lock
);
248 if (!ret
&& !ignore_state
) {
249 if (!wait_task_inactive(child
, __TASK_TRACED
)) {
251 * This can only happen if may_ptrace_stop() fails and
252 * ptrace_stop() changes ->state back to TASK_RUNNING,
253 * so we should not worry about leaking __TASK_TRACED.
255 WARN_ON(child
->state
== __TASK_TRACED
);
263 static int ptrace_has_cap(struct user_namespace
*ns
, unsigned int mode
)
265 if (mode
& PTRACE_MODE_NOAUDIT
)
266 return has_ns_capability_noaudit(current
, ns
, CAP_SYS_PTRACE
);
268 return has_ns_capability(current
, ns
, CAP_SYS_PTRACE
);
271 /* Returns 0 on success, -errno on denial. */
272 static int __ptrace_may_access(struct task_struct
*task
, unsigned int mode
)
274 const struct cred
*cred
= current_cred(), *tcred
;
275 struct mm_struct
*mm
;
279 if (!(mode
& PTRACE_MODE_FSCREDS
) == !(mode
& PTRACE_MODE_REALCREDS
)) {
280 WARN(1, "denying ptrace access check without PTRACE_MODE_*CREDS\n");
284 /* May we inspect the given task?
285 * This check is used both for attaching with ptrace
286 * and for allowing access to sensitive information in /proc.
288 * ptrace_attach denies several cases that /proc allows
289 * because setting up the necessary parent/child relationship
290 * or halting the specified task is impossible.
293 /* Don't let security modules deny introspection */
294 if (same_thread_group(task
, current
))
297 if (mode
& PTRACE_MODE_FSCREDS
) {
298 caller_uid
= cred
->fsuid
;
299 caller_gid
= cred
->fsgid
;
302 * Using the euid would make more sense here, but something
303 * in userland might rely on the old behavior, and this
304 * shouldn't be a security problem since
305 * PTRACE_MODE_REALCREDS implies that the caller explicitly
306 * used a syscall that requests access to another process
307 * (and not a filesystem syscall to procfs).
309 caller_uid
= cred
->uid
;
310 caller_gid
= cred
->gid
;
312 tcred
= __task_cred(task
);
313 if (uid_eq(caller_uid
, tcred
->euid
) &&
314 uid_eq(caller_uid
, tcred
->suid
) &&
315 uid_eq(caller_uid
, tcred
->uid
) &&
316 gid_eq(caller_gid
, tcred
->egid
) &&
317 gid_eq(caller_gid
, tcred
->sgid
) &&
318 gid_eq(caller_gid
, tcred
->gid
))
320 if (ptrace_has_cap(tcred
->user_ns
, mode
))
327 * If a task drops privileges and becomes nondumpable (through a syscall
328 * like setresuid()) while we are trying to access it, we must ensure
329 * that the dumpability is read after the credentials; otherwise,
330 * we may be able to attach to a task that we shouldn't be able to
331 * attach to (as if the task had dropped privileges without becoming
333 * Pairs with a write barrier in commit_creds().
338 ((get_dumpable(mm
) != SUID_DUMP_USER
) &&
339 !ptrace_has_cap(mm
->user_ns
, mode
)))
342 return security_ptrace_access_check(task
, mode
);
345 bool ptrace_may_access(struct task_struct
*task
, unsigned int mode
)
349 err
= __ptrace_may_access(task
, mode
);
354 static int ptrace_attach(struct task_struct
*task
, long request
,
358 bool seize
= (request
== PTRACE_SEIZE
);
365 if (flags
& ~(unsigned long)PTRACE_O_MASK
)
367 flags
= PT_PTRACED
| PT_SEIZED
| (flags
<< PT_OPT_FLAG_SHIFT
);
375 if (unlikely(task
->flags
& PF_KTHREAD
))
377 if (same_thread_group(task
, current
))
381 * Protect exec's credential calculations against our interference;
382 * SUID, SGID and LSM creds get determined differently
385 retval
= -ERESTARTNOINTR
;
386 if (mutex_lock_interruptible(&task
->signal
->cred_guard_mutex
))
390 retval
= __ptrace_may_access(task
, PTRACE_MODE_ATTACH_REALCREDS
);
395 write_lock_irq(&tasklist_lock
);
397 if (unlikely(task
->exit_state
))
398 goto unlock_tasklist
;
400 goto unlock_tasklist
;
404 task
->ptrace
= flags
;
406 ptrace_link(task
, current
);
408 /* SEIZE doesn't trap tracee on attach */
410 send_sig_info(SIGSTOP
, SEND_SIG_FORCED
, task
);
412 spin_lock(&task
->sighand
->siglock
);
415 * If the task is already STOPPED, set JOBCTL_TRAP_STOP and
416 * TRAPPING, and kick it so that it transits to TRACED. TRAPPING
417 * will be cleared if the child completes the transition or any
418 * event which clears the group stop states happens. We'll wait
419 * for the transition to complete before returning from this
422 * This hides STOPPED -> RUNNING -> TRACED transition from the
423 * attaching thread but a different thread in the same group can
424 * still observe the transient RUNNING state. IOW, if another
425 * thread's WNOHANG wait(2) on the stopped tracee races against
426 * ATTACH, the wait(2) may fail due to the transient RUNNING.
428 * The following task_is_stopped() test is safe as both transitions
429 * in and out of STOPPED are protected by siglock.
431 if (task_is_stopped(task
) &&
432 task_set_jobctl_pending(task
, JOBCTL_TRAP_STOP
| JOBCTL_TRAPPING
))
433 signal_wake_up_state(task
, __TASK_STOPPED
);
435 spin_unlock(&task
->sighand
->siglock
);
439 write_unlock_irq(&tasklist_lock
);
441 mutex_unlock(&task
->signal
->cred_guard_mutex
);
445 * We do not bother to change retval or clear JOBCTL_TRAPPING
446 * if wait_on_bit() was interrupted by SIGKILL. The tracer will
447 * not return to user-mode, it will exit and clear this bit in
448 * __ptrace_unlink() if it wasn't already cleared by the tracee;
449 * and until then nobody can ptrace this task.
451 wait_on_bit(&task
->jobctl
, JOBCTL_TRAPPING_BIT
, TASK_KILLABLE
);
452 proc_ptrace_connector(task
, PTRACE_ATTACH
);
459 * ptrace_traceme -- helper for PTRACE_TRACEME
461 * Performs checks and sets PT_PTRACED.
462 * Should be used by all ptrace implementations for PTRACE_TRACEME.
464 static int ptrace_traceme(void)
468 write_lock_irq(&tasklist_lock
);
469 /* Are we already being traced? */
470 if (!current
->ptrace
) {
471 ret
= security_ptrace_traceme(current
->parent
);
473 * Check PF_EXITING to ensure ->real_parent has not passed
474 * exit_ptrace(). Otherwise we don't report the error but
475 * pretend ->real_parent untraces us right after return.
477 if (!ret
&& !(current
->real_parent
->flags
& PF_EXITING
)) {
478 current
->ptrace
= PT_PTRACED
;
479 ptrace_link(current
, current
->real_parent
);
482 write_unlock_irq(&tasklist_lock
);
488 * Called with irqs disabled, returns true if childs should reap themselves.
490 static int ignoring_children(struct sighand_struct
*sigh
)
493 spin_lock(&sigh
->siglock
);
494 ret
= (sigh
->action
[SIGCHLD
-1].sa
.sa_handler
== SIG_IGN
) ||
495 (sigh
->action
[SIGCHLD
-1].sa
.sa_flags
& SA_NOCLDWAIT
);
496 spin_unlock(&sigh
->siglock
);
501 * Called with tasklist_lock held for writing.
502 * Unlink a traced task, and clean it up if it was a traced zombie.
503 * Return true if it needs to be reaped with release_task().
504 * (We can't call release_task() here because we already hold tasklist_lock.)
506 * If it's a zombie, our attachedness prevented normal parent notification
507 * or self-reaping. Do notification now if it would have happened earlier.
508 * If it should reap itself, return true.
510 * If it's our own child, there is no notification to do. But if our normal
511 * children self-reap, then this child was prevented by ptrace and we must
512 * reap it now, in that case we must also wake up sub-threads sleeping in
515 static bool __ptrace_detach(struct task_struct
*tracer
, struct task_struct
*p
)
521 if (p
->exit_state
!= EXIT_ZOMBIE
)
524 dead
= !thread_group_leader(p
);
526 if (!dead
&& thread_group_empty(p
)) {
527 if (!same_thread_group(p
->real_parent
, tracer
))
528 dead
= do_notify_parent(p
, p
->exit_signal
);
529 else if (ignoring_children(tracer
->sighand
)) {
530 __wake_up_parent(p
, tracer
);
534 /* Mark it as in the process of being reaped. */
536 p
->exit_state
= EXIT_DEAD
;
540 static int ptrace_detach(struct task_struct
*child
, unsigned int data
)
542 if (!valid_signal(data
))
545 /* Architecture-specific hardware disable .. */
546 ptrace_disable(child
);
548 write_lock_irq(&tasklist_lock
);
550 * We rely on ptrace_freeze_traced(). It can't be killed and
551 * untraced by another thread, it can't be a zombie.
553 WARN_ON(!child
->ptrace
|| child
->exit_state
);
555 * tasklist_lock avoids the race with wait_task_stopped(), see
556 * the comment in ptrace_resume().
558 child
->exit_code
= data
;
559 __ptrace_detach(current
, child
);
560 write_unlock_irq(&tasklist_lock
);
562 proc_ptrace_connector(child
, PTRACE_DETACH
);
568 * Detach all tasks we were using ptrace on. Called with tasklist held
571 void exit_ptrace(struct task_struct
*tracer
, struct list_head
*dead
)
573 struct task_struct
*p
, *n
;
575 list_for_each_entry_safe(p
, n
, &tracer
->ptraced
, ptrace_entry
) {
576 if (unlikely(p
->ptrace
& PT_EXITKILL
))
577 send_sig_info(SIGKILL
, SEND_SIG_FORCED
, p
);
579 if (__ptrace_detach(tracer
, p
))
580 list_add(&p
->ptrace_entry
, dead
);
584 int ptrace_readdata(struct task_struct
*tsk
, unsigned long src
, char __user
*dst
, int len
)
590 int this_len
, retval
;
592 this_len
= (len
> sizeof(buf
)) ? sizeof(buf
) : len
;
593 retval
= ptrace_access_vm(tsk
, src
, buf
, this_len
, FOLL_FORCE
);
600 if (copy_to_user(dst
, buf
, retval
))
610 int ptrace_writedata(struct task_struct
*tsk
, char __user
*src
, unsigned long dst
, int len
)
616 int this_len
, retval
;
618 this_len
= (len
> sizeof(buf
)) ? sizeof(buf
) : len
;
619 if (copy_from_user(buf
, src
, this_len
))
621 retval
= ptrace_access_vm(tsk
, dst
, buf
, this_len
,
622 FOLL_FORCE
| FOLL_WRITE
);
636 static int ptrace_setoptions(struct task_struct
*child
, unsigned long data
)
640 if (data
& ~(unsigned long)PTRACE_O_MASK
)
643 if (unlikely(data
& PTRACE_O_SUSPEND_SECCOMP
)) {
644 if (!IS_ENABLED(CONFIG_CHECKPOINT_RESTORE
) ||
645 !IS_ENABLED(CONFIG_SECCOMP
))
648 if (!capable(CAP_SYS_ADMIN
))
651 if (seccomp_mode(¤t
->seccomp
) != SECCOMP_MODE_DISABLED
||
652 current
->ptrace
& PT_SUSPEND_SECCOMP
)
656 /* Avoid intermediate state when all opts are cleared */
657 flags
= child
->ptrace
;
658 flags
&= ~(PTRACE_O_MASK
<< PT_OPT_FLAG_SHIFT
);
659 flags
|= (data
<< PT_OPT_FLAG_SHIFT
);
660 child
->ptrace
= flags
;
665 static int ptrace_getsiginfo(struct task_struct
*child
, siginfo_t
*info
)
670 if (lock_task_sighand(child
, &flags
)) {
672 if (likely(child
->last_siginfo
!= NULL
)) {
673 copy_siginfo(info
, child
->last_siginfo
);
676 unlock_task_sighand(child
, &flags
);
681 static int ptrace_setsiginfo(struct task_struct
*child
, const siginfo_t
*info
)
686 if (lock_task_sighand(child
, &flags
)) {
688 if (likely(child
->last_siginfo
!= NULL
)) {
689 copy_siginfo(child
->last_siginfo
, info
);
692 unlock_task_sighand(child
, &flags
);
697 static int ptrace_peek_siginfo(struct task_struct
*child
,
701 struct ptrace_peeksiginfo_args arg
;
702 struct sigpending
*pending
;
706 ret
= copy_from_user(&arg
, (void __user
*) addr
,
707 sizeof(struct ptrace_peeksiginfo_args
));
711 if (arg
.flags
& ~PTRACE_PEEKSIGINFO_SHARED
)
712 return -EINVAL
; /* unknown flags */
717 /* Ensure arg.off fits in an unsigned long */
718 if (arg
.off
> ULONG_MAX
)
721 if (arg
.flags
& PTRACE_PEEKSIGINFO_SHARED
)
722 pending
= &child
->signal
->shared_pending
;
724 pending
= &child
->pending
;
726 for (i
= 0; i
< arg
.nr
; ) {
728 unsigned long off
= arg
.off
+ i
;
731 spin_lock_irq(&child
->sighand
->siglock
);
732 list_for_each_entry(q
, &pending
->list
, list
) {
735 copy_siginfo(&info
, &q
->info
);
739 spin_unlock_irq(&child
->sighand
->siglock
);
741 if (!found
) /* beyond the end of the list */
745 if (unlikely(in_compat_syscall())) {
746 compat_siginfo_t __user
*uinfo
= compat_ptr(data
);
748 if (copy_siginfo_to_user32(uinfo
, &info
)) {
756 siginfo_t __user
*uinfo
= (siginfo_t __user
*) data
;
758 if (copy_siginfo_to_user(uinfo
, &info
)) {
764 data
+= sizeof(siginfo_t
);
767 if (signal_pending(current
))
779 #ifdef PTRACE_SINGLESTEP
780 #define is_singlestep(request) ((request) == PTRACE_SINGLESTEP)
782 #define is_singlestep(request) 0
785 #ifdef PTRACE_SINGLEBLOCK
786 #define is_singleblock(request) ((request) == PTRACE_SINGLEBLOCK)
788 #define is_singleblock(request) 0
792 #define is_sysemu_singlestep(request) ((request) == PTRACE_SYSEMU_SINGLESTEP)
794 #define is_sysemu_singlestep(request) 0
797 static int ptrace_resume(struct task_struct
*child
, long request
,
802 if (!valid_signal(data
))
805 if (request
== PTRACE_SYSCALL
)
806 set_tsk_thread_flag(child
, TIF_SYSCALL_TRACE
);
808 clear_tsk_thread_flag(child
, TIF_SYSCALL_TRACE
);
810 #ifdef TIF_SYSCALL_EMU
811 if (request
== PTRACE_SYSEMU
|| request
== PTRACE_SYSEMU_SINGLESTEP
)
812 set_tsk_thread_flag(child
, TIF_SYSCALL_EMU
);
814 clear_tsk_thread_flag(child
, TIF_SYSCALL_EMU
);
817 if (is_singleblock(request
)) {
818 if (unlikely(!arch_has_block_step()))
820 user_enable_block_step(child
);
821 } else if (is_singlestep(request
) || is_sysemu_singlestep(request
)) {
822 if (unlikely(!arch_has_single_step()))
824 user_enable_single_step(child
);
826 user_disable_single_step(child
);
830 * Change ->exit_code and ->state under siglock to avoid the race
831 * with wait_task_stopped() in between; a non-zero ->exit_code will
832 * wrongly look like another report from tracee.
834 * Note that we need siglock even if ->exit_code == data and/or this
835 * status was not reported yet, the new status must not be cleared by
836 * wait_task_stopped() after resume.
838 * If data == 0 we do not care if wait_task_stopped() reports the old
839 * status and clears the code too; this can't race with the tracee, it
840 * takes siglock after resume.
842 need_siglock
= data
&& !thread_group_empty(current
);
844 spin_lock_irq(&child
->sighand
->siglock
);
845 child
->exit_code
= data
;
846 wake_up_state(child
, __TASK_TRACED
);
848 spin_unlock_irq(&child
->sighand
->siglock
);
853 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
855 static const struct user_regset
*
856 find_regset(const struct user_regset_view
*view
, unsigned int type
)
858 const struct user_regset
*regset
;
861 for (n
= 0; n
< view
->n
; ++n
) {
862 regset
= view
->regsets
+ n
;
863 if (regset
->core_note_type
== type
)
870 static int ptrace_regset(struct task_struct
*task
, int req
, unsigned int type
,
873 const struct user_regset_view
*view
= task_user_regset_view(task
);
874 const struct user_regset
*regset
= find_regset(view
, type
);
877 if (!regset
|| (kiov
->iov_len
% regset
->size
) != 0)
880 regset_no
= regset
- view
->regsets
;
881 kiov
->iov_len
= min(kiov
->iov_len
,
882 (__kernel_size_t
) (regset
->n
* regset
->size
));
884 if (req
== PTRACE_GETREGSET
)
885 return copy_regset_to_user(task
, view
, regset_no
, 0,
886 kiov
->iov_len
, kiov
->iov_base
);
888 return copy_regset_from_user(task
, view
, regset_no
, 0,
889 kiov
->iov_len
, kiov
->iov_base
);
893 * This is declared in linux/regset.h and defined in machine-dependent
894 * code. We put the export here, near the primary machine-neutral use,
895 * to ensure no machine forgets it.
897 EXPORT_SYMBOL_GPL(task_user_regset_view
);
900 int ptrace_request(struct task_struct
*child
, long request
,
901 unsigned long addr
, unsigned long data
)
903 bool seized
= child
->ptrace
& PT_SEIZED
;
905 siginfo_t siginfo
, *si
;
906 void __user
*datavp
= (void __user
*) data
;
907 unsigned long __user
*datalp
= datavp
;
911 case PTRACE_PEEKTEXT
:
912 case PTRACE_PEEKDATA
:
913 return generic_ptrace_peekdata(child
, addr
, data
);
914 case PTRACE_POKETEXT
:
915 case PTRACE_POKEDATA
:
916 return generic_ptrace_pokedata(child
, addr
, data
);
918 #ifdef PTRACE_OLDSETOPTIONS
919 case PTRACE_OLDSETOPTIONS
:
921 case PTRACE_SETOPTIONS
:
922 ret
= ptrace_setoptions(child
, data
);
924 case PTRACE_GETEVENTMSG
:
925 ret
= put_user(child
->ptrace_message
, datalp
);
928 case PTRACE_PEEKSIGINFO
:
929 ret
= ptrace_peek_siginfo(child
, addr
, data
);
932 case PTRACE_GETSIGINFO
:
933 ret
= ptrace_getsiginfo(child
, &siginfo
);
935 ret
= copy_siginfo_to_user(datavp
, &siginfo
);
938 case PTRACE_SETSIGINFO
:
939 if (copy_from_user(&siginfo
, datavp
, sizeof siginfo
))
942 ret
= ptrace_setsiginfo(child
, &siginfo
);
945 case PTRACE_GETSIGMASK
: {
948 if (addr
!= sizeof(sigset_t
)) {
953 if (test_tsk_restore_sigmask(child
))
954 mask
= &child
->saved_sigmask
;
956 mask
= &child
->blocked
;
958 if (copy_to_user(datavp
, mask
, sizeof(sigset_t
)))
966 case PTRACE_SETSIGMASK
: {
969 if (addr
!= sizeof(sigset_t
)) {
974 if (copy_from_user(&new_set
, datavp
, sizeof(sigset_t
))) {
979 sigdelsetmask(&new_set
, sigmask(SIGKILL
)|sigmask(SIGSTOP
));
982 * Every thread does recalc_sigpending() after resume, so
983 * retarget_shared_pending() and recalc_sigpending() are not
986 spin_lock_irq(&child
->sighand
->siglock
);
987 child
->blocked
= new_set
;
988 spin_unlock_irq(&child
->sighand
->siglock
);
990 clear_tsk_restore_sigmask(child
);
996 case PTRACE_INTERRUPT
:
998 * Stop tracee without any side-effect on signal or job
999 * control. At least one trap is guaranteed to happen
1000 * after this request. If @child is already trapped, the
1001 * current trap is not disturbed and another trap will
1002 * happen after the current trap is ended with PTRACE_CONT.
1004 * The actual trap might not be PTRACE_EVENT_STOP trap but
1005 * the pending condition is cleared regardless.
1007 if (unlikely(!seized
|| !lock_task_sighand(child
, &flags
)))
1011 * INTERRUPT doesn't disturb existing trap sans one
1012 * exception. If ptracer issued LISTEN for the current
1013 * STOP, this INTERRUPT should clear LISTEN and re-trap
1016 if (likely(task_set_jobctl_pending(child
, JOBCTL_TRAP_STOP
)))
1017 ptrace_signal_wake_up(child
, child
->jobctl
& JOBCTL_LISTENING
);
1019 unlock_task_sighand(child
, &flags
);
1025 * Listen for events. Tracee must be in STOP. It's not
1026 * resumed per-se but is not considered to be in TRACED by
1027 * wait(2) or ptrace(2). If an async event (e.g. group
1028 * stop state change) happens, tracee will enter STOP trap
1029 * again. Alternatively, ptracer can issue INTERRUPT to
1030 * finish listening and re-trap tracee into STOP.
1032 if (unlikely(!seized
|| !lock_task_sighand(child
, &flags
)))
1035 si
= child
->last_siginfo
;
1036 if (likely(si
&& (si
->si_code
>> 8) == PTRACE_EVENT_STOP
)) {
1037 child
->jobctl
|= JOBCTL_LISTENING
;
1039 * If NOTIFY is set, it means event happened between
1040 * start of this trap and now. Trigger re-trap.
1042 if (child
->jobctl
& JOBCTL_TRAP_NOTIFY
)
1043 ptrace_signal_wake_up(child
, true);
1046 unlock_task_sighand(child
, &flags
);
1049 case PTRACE_DETACH
: /* detach a process that was attached. */
1050 ret
= ptrace_detach(child
, data
);
1053 #ifdef CONFIG_BINFMT_ELF_FDPIC
1054 case PTRACE_GETFDPIC
: {
1055 struct mm_struct
*mm
= get_task_mm(child
);
1056 unsigned long tmp
= 0;
1063 case PTRACE_GETFDPIC_EXEC
:
1064 tmp
= mm
->context
.exec_fdpic_loadmap
;
1066 case PTRACE_GETFDPIC_INTERP
:
1067 tmp
= mm
->context
.interp_fdpic_loadmap
;
1074 ret
= put_user(tmp
, datalp
);
1079 #ifdef PTRACE_SINGLESTEP
1080 case PTRACE_SINGLESTEP
:
1082 #ifdef PTRACE_SINGLEBLOCK
1083 case PTRACE_SINGLEBLOCK
:
1085 #ifdef PTRACE_SYSEMU
1087 case PTRACE_SYSEMU_SINGLESTEP
:
1089 case PTRACE_SYSCALL
:
1091 return ptrace_resume(child
, request
, data
);
1094 if (child
->exit_state
) /* already dead */
1096 return ptrace_resume(child
, request
, SIGKILL
);
1098 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
1099 case PTRACE_GETREGSET
:
1100 case PTRACE_SETREGSET
: {
1102 struct iovec __user
*uiov
= datavp
;
1104 if (!access_ok(VERIFY_WRITE
, uiov
, sizeof(*uiov
)))
1107 if (__get_user(kiov
.iov_base
, &uiov
->iov_base
) ||
1108 __get_user(kiov
.iov_len
, &uiov
->iov_len
))
1111 ret
= ptrace_regset(child
, request
, addr
, &kiov
);
1113 ret
= __put_user(kiov
.iov_len
, &uiov
->iov_len
);
1118 case PTRACE_SECCOMP_GET_FILTER
:
1119 ret
= seccomp_get_filter(child
, addr
, datavp
);
1122 case PTRACE_SECCOMP_GET_METADATA
:
1123 ret
= seccomp_get_metadata(child
, addr
, datavp
);
1133 #ifndef arch_ptrace_attach
1134 #define arch_ptrace_attach(child) do { } while (0)
1137 SYSCALL_DEFINE4(ptrace
, long, request
, long, pid
, unsigned long, addr
,
1138 unsigned long, data
)
1140 struct task_struct
*child
;
1143 if (request
== PTRACE_TRACEME
) {
1144 ret
= ptrace_traceme();
1146 arch_ptrace_attach(current
);
1150 child
= find_get_task_by_vpid(pid
);
1156 if (request
== PTRACE_ATTACH
|| request
== PTRACE_SEIZE
) {
1157 ret
= ptrace_attach(child
, request
, addr
, data
);
1159 * Some architectures need to do book-keeping after
1163 arch_ptrace_attach(child
);
1164 goto out_put_task_struct
;
1167 ret
= ptrace_check_attach(child
, request
== PTRACE_KILL
||
1168 request
== PTRACE_INTERRUPT
);
1170 goto out_put_task_struct
;
1172 ret
= arch_ptrace(child
, request
, addr
, data
);
1173 if (ret
|| request
!= PTRACE_DETACH
)
1174 ptrace_unfreeze_traced(child
);
1176 out_put_task_struct
:
1177 put_task_struct(child
);
1182 int generic_ptrace_peekdata(struct task_struct
*tsk
, unsigned long addr
,
1188 copied
= ptrace_access_vm(tsk
, addr
, &tmp
, sizeof(tmp
), FOLL_FORCE
);
1189 if (copied
!= sizeof(tmp
))
1191 return put_user(tmp
, (unsigned long __user
*)data
);
1194 int generic_ptrace_pokedata(struct task_struct
*tsk
, unsigned long addr
,
1199 copied
= ptrace_access_vm(tsk
, addr
, &data
, sizeof(data
),
1200 FOLL_FORCE
| FOLL_WRITE
);
1201 return (copied
== sizeof(data
)) ? 0 : -EIO
;
1204 #if defined CONFIG_COMPAT
1206 int compat_ptrace_request(struct task_struct
*child
, compat_long_t request
,
1207 compat_ulong_t addr
, compat_ulong_t data
)
1209 compat_ulong_t __user
*datap
= compat_ptr(data
);
1210 compat_ulong_t word
;
1215 case PTRACE_PEEKTEXT
:
1216 case PTRACE_PEEKDATA
:
1217 ret
= ptrace_access_vm(child
, addr
, &word
, sizeof(word
),
1219 if (ret
!= sizeof(word
))
1222 ret
= put_user(word
, datap
);
1225 case PTRACE_POKETEXT
:
1226 case PTRACE_POKEDATA
:
1227 ret
= ptrace_access_vm(child
, addr
, &data
, sizeof(data
),
1228 FOLL_FORCE
| FOLL_WRITE
);
1229 ret
= (ret
!= sizeof(data
) ? -EIO
: 0);
1232 case PTRACE_GETEVENTMSG
:
1233 ret
= put_user((compat_ulong_t
) child
->ptrace_message
, datap
);
1236 case PTRACE_GETSIGINFO
:
1237 ret
= ptrace_getsiginfo(child
, &siginfo
);
1239 ret
= copy_siginfo_to_user32(
1240 (struct compat_siginfo __user
*) datap
,
1244 case PTRACE_SETSIGINFO
:
1245 if (copy_siginfo_from_user32(
1246 &siginfo
, (struct compat_siginfo __user
*) datap
))
1249 ret
= ptrace_setsiginfo(child
, &siginfo
);
1251 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
1252 case PTRACE_GETREGSET
:
1253 case PTRACE_SETREGSET
:
1256 struct compat_iovec __user
*uiov
=
1257 (struct compat_iovec __user
*) datap
;
1261 if (!access_ok(VERIFY_WRITE
, uiov
, sizeof(*uiov
)))
1264 if (__get_user(ptr
, &uiov
->iov_base
) ||
1265 __get_user(len
, &uiov
->iov_len
))
1268 kiov
.iov_base
= compat_ptr(ptr
);
1271 ret
= ptrace_regset(child
, request
, addr
, &kiov
);
1273 ret
= __put_user(kiov
.iov_len
, &uiov
->iov_len
);
1279 ret
= ptrace_request(child
, request
, addr
, data
);
1285 COMPAT_SYSCALL_DEFINE4(ptrace
, compat_long_t
, request
, compat_long_t
, pid
,
1286 compat_long_t
, addr
, compat_long_t
, data
)
1288 struct task_struct
*child
;
1291 if (request
== PTRACE_TRACEME
) {
1292 ret
= ptrace_traceme();
1296 child
= find_get_task_by_vpid(pid
);
1302 if (request
== PTRACE_ATTACH
|| request
== PTRACE_SEIZE
) {
1303 ret
= ptrace_attach(child
, request
, addr
, data
);
1305 * Some architectures need to do book-keeping after
1309 arch_ptrace_attach(child
);
1310 goto out_put_task_struct
;
1313 ret
= ptrace_check_attach(child
, request
== PTRACE_KILL
||
1314 request
== PTRACE_INTERRUPT
);
1316 ret
= compat_arch_ptrace(child
, request
, addr
, data
);
1317 if (ret
|| request
!= PTRACE_DETACH
)
1318 ptrace_unfreeze_traced(child
);
1321 out_put_task_struct
:
1322 put_task_struct(child
);
1326 #endif /* CONFIG_COMPAT */