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>
34 * Access another process' address space via ptrace.
35 * Source/target buffer must be kernel space,
36 * Do not walk the page table directly, use get_user_pages
38 int ptrace_access_vm(struct task_struct *tsk, unsigned long addr,
39 void *buf, int len, unsigned int gup_flags)
44 mm = get_task_mm(tsk);
49 (current != tsk->parent) ||
50 ((get_dumpable(mm) != SUID_DUMP_USER) &&
51 !ptracer_capable(tsk, mm->user_ns))) {
56 ret = __access_remote_vm(tsk, mm, addr, buf, len, gup_flags);
63 void __ptrace_link(struct task_struct *child, struct task_struct *new_parent,
64 const struct cred *ptracer_cred)
66 BUG_ON(!list_empty(&child->ptrace_entry));
67 list_add(&child->ptrace_entry, &new_parent->ptraced);
68 child->parent = new_parent;
69 child->ptracer_cred = get_cred(ptracer_cred);
73 * ptrace a task: make the debugger its new parent and
74 * move it to the ptrace list.
76 * Must be called with the tasklist lock write-held.
78 static void ptrace_link(struct task_struct *child, struct task_struct *new_parent)
81 __ptrace_link(child, new_parent, __task_cred(new_parent));
86 * __ptrace_unlink - unlink ptracee and restore its execution state
87 * @child: ptracee to be unlinked
89 * Remove @child from the ptrace list, move it back to the original parent,
90 * and restore the execution state so that it conforms to the group stop
93 * Unlinking can happen via two paths - explicit PTRACE_DETACH or ptracer
94 * exiting. For PTRACE_DETACH, unless the ptracee has been killed between
95 * ptrace_check_attach() and here, it's guaranteed to be in TASK_TRACED.
96 * If the ptracer is exiting, the ptracee can be in any state.
98 * After detach, the ptracee should be in a state which conforms to the
99 * group stop. If the group is stopped or in the process of stopping, the
100 * ptracee should be put into TASK_STOPPED; otherwise, it should be woken
101 * up from TASK_TRACED.
103 * If the ptracee is in TASK_TRACED and needs to be moved to TASK_STOPPED,
104 * it goes through TRACED -> RUNNING -> STOPPED transition which is similar
105 * to but in the opposite direction of what happens while attaching to a
106 * stopped task. However, in this direction, the intermediate RUNNING
107 * state is not hidden even from the current ptracer and if it immediately
108 * re-attaches and performs a WNOHANG wait(2), it may fail.
111 * write_lock_irq(tasklist_lock)
113 void __ptrace_unlink(struct task_struct *child)
115 const struct cred *old_cred;
116 BUG_ON(!child->ptrace);
118 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
120 child->parent = child->real_parent;
121 list_del_init(&child->ptrace_entry);
122 old_cred = child->ptracer_cred;
123 child->ptracer_cred = NULL;
126 spin_lock(&child->sighand->siglock);
129 * Clear all pending traps and TRAPPING. TRAPPING should be
130 * cleared regardless of JOBCTL_STOP_PENDING. Do it explicitly.
132 task_clear_jobctl_pending(child, JOBCTL_TRAP_MASK);
133 task_clear_jobctl_trapping(child);
136 * Reinstate JOBCTL_STOP_PENDING if group stop is in effect and
139 if (!(child->flags & PF_EXITING) &&
140 (child->signal->flags & SIGNAL_STOP_STOPPED ||
141 child->signal->group_stop_count)) {
142 child->jobctl |= JOBCTL_STOP_PENDING;
145 * This is only possible if this thread was cloned by the
146 * traced task running in the stopped group, set the signal
147 * for the future reports.
148 * FIXME: we should change ptrace_init_task() to handle this
151 if (!(child->jobctl & JOBCTL_STOP_SIGMASK))
152 child->jobctl |= SIGSTOP;
156 * If transition to TASK_STOPPED is pending or in TASK_TRACED, kick
157 * @child in the butt. Note that @resume should be used iff @child
158 * is in TASK_TRACED; otherwise, we might unduly disrupt
159 * TASK_KILLABLE sleeps.
161 if (child->jobctl & JOBCTL_STOP_PENDING || task_is_traced(child))
162 ptrace_signal_wake_up(child, true);
164 spin_unlock(&child->sighand->siglock);
167 /* Ensure that nothing can wake it up, even SIGKILL */
168 static bool ptrace_freeze_traced(struct task_struct *task)
172 /* Lockless, nobody but us can set this flag */
173 if (task->jobctl & JOBCTL_LISTENING)
176 spin_lock_irq(&task->sighand->siglock);
177 if (task_is_traced(task) && !__fatal_signal_pending(task)) {
178 task->state = __TASK_TRACED;
181 spin_unlock_irq(&task->sighand->siglock);
186 static void ptrace_unfreeze_traced(struct task_struct *task)
188 if (task->state != __TASK_TRACED)
191 WARN_ON(!task->ptrace || task->parent != current);
194 * PTRACE_LISTEN can allow ptrace_trap_notify to wake us up remotely.
195 * Recheck state under the lock to close this race.
197 spin_lock_irq(&task->sighand->siglock);
198 if (task->state == __TASK_TRACED) {
199 if (__fatal_signal_pending(task))
200 wake_up_state(task, __TASK_TRACED);
202 task->state = TASK_TRACED;
204 spin_unlock_irq(&task->sighand->siglock);
208 * ptrace_check_attach - check whether ptracee is ready for ptrace operation
209 * @child: ptracee to check for
210 * @ignore_state: don't check whether @child is currently %TASK_TRACED
212 * Check whether @child is being ptraced by %current and ready for further
213 * ptrace operations. If @ignore_state is %false, @child also should be in
214 * %TASK_TRACED state and on return the child is guaranteed to be traced
215 * and not executing. If @ignore_state is %true, @child can be in any
219 * Grabs and releases tasklist_lock and @child->sighand->siglock.
222 * 0 on success, -ESRCH if %child is not ready.
224 static int ptrace_check_attach(struct task_struct *child, bool ignore_state)
229 * We take the read lock around doing both checks to close a
230 * possible race where someone else was tracing our child and
231 * detached between these two checks. After this locked check,
232 * we are sure that this is our traced child and that can only
233 * be changed by us so it's not changing right after this.
235 read_lock(&tasklist_lock);
236 if (child->ptrace && child->parent == current) {
237 WARN_ON(child->state == __TASK_TRACED);
239 * child->sighand can't be NULL, release_task()
240 * does ptrace_unlink() before __exit_signal().
242 if (ignore_state || ptrace_freeze_traced(child))
245 read_unlock(&tasklist_lock);
247 if (!ret && !ignore_state) {
248 if (!wait_task_inactive(child, __TASK_TRACED)) {
250 * This can only happen if may_ptrace_stop() fails and
251 * ptrace_stop() changes ->state back to TASK_RUNNING,
252 * so we should not worry about leaking __TASK_TRACED.
254 WARN_ON(child->state == __TASK_TRACED);
262 static int ptrace_has_cap(struct user_namespace *ns, unsigned int mode)
264 if (mode & PTRACE_MODE_NOAUDIT)
265 return has_ns_capability_noaudit(current, ns, CAP_SYS_PTRACE);
267 return has_ns_capability(current, ns, CAP_SYS_PTRACE);
270 /* Returns 0 on success, -errno on denial. */
271 static int __ptrace_may_access(struct task_struct *task, unsigned int mode)
273 const struct cred *cred = current_cred(), *tcred;
274 struct mm_struct *mm;
278 if (!(mode & PTRACE_MODE_FSCREDS) == !(mode & PTRACE_MODE_REALCREDS)) {
279 WARN(1, "denying ptrace access check without PTRACE_MODE_*CREDS\n");
283 /* May we inspect the given task?
284 * This check is used both for attaching with ptrace
285 * and for allowing access to sensitive information in /proc.
287 * ptrace_attach denies several cases that /proc allows
288 * because setting up the necessary parent/child relationship
289 * or halting the specified task is impossible.
292 /* Don't let security modules deny introspection */
293 if (same_thread_group(task, current))
296 if (mode & PTRACE_MODE_FSCREDS) {
297 caller_uid = cred->fsuid;
298 caller_gid = cred->fsgid;
301 * Using the euid would make more sense here, but something
302 * in userland might rely on the old behavior, and this
303 * shouldn't be a security problem since
304 * PTRACE_MODE_REALCREDS implies that the caller explicitly
305 * used a syscall that requests access to another process
306 * (and not a filesystem syscall to procfs).
308 caller_uid = cred->uid;
309 caller_gid = cred->gid;
311 tcred = __task_cred(task);
312 if (uid_eq(caller_uid, tcred->euid) &&
313 uid_eq(caller_uid, tcred->suid) &&
314 uid_eq(caller_uid, tcred->uid) &&
315 gid_eq(caller_gid, tcred->egid) &&
316 gid_eq(caller_gid, tcred->sgid) &&
317 gid_eq(caller_gid, tcred->gid))
319 if (ptrace_has_cap(tcred->user_ns, mode))
327 ((get_dumpable(mm) != SUID_DUMP_USER) &&
328 !ptrace_has_cap(mm->user_ns, mode)))
331 return security_ptrace_access_check(task, mode);
334 bool ptrace_may_access(struct task_struct *task, unsigned int mode)
338 err = __ptrace_may_access(task, mode);
343 static int ptrace_attach(struct task_struct *task, long request,
347 bool seize = (request == PTRACE_SEIZE);
354 if (flags & ~(unsigned long)PTRACE_O_MASK)
356 flags = PT_PTRACED | PT_SEIZED | (flags << PT_OPT_FLAG_SHIFT);
364 if (unlikely(task->flags & PF_KTHREAD))
366 if (same_thread_group(task, current))
370 * Protect exec's credential calculations against our interference;
371 * SUID, SGID and LSM creds get determined differently
374 retval = -ERESTARTNOINTR;
375 if (mutex_lock_interruptible(&task->signal->cred_guard_mutex))
379 retval = __ptrace_may_access(task, PTRACE_MODE_ATTACH_REALCREDS);
384 write_lock_irq(&tasklist_lock);
386 if (unlikely(task->exit_state))
387 goto unlock_tasklist;
389 goto unlock_tasklist;
393 task->ptrace = flags;
395 ptrace_link(task, current);
397 /* SEIZE doesn't trap tracee on attach */
399 send_sig_info(SIGSTOP, SEND_SIG_PRIV, task);
401 spin_lock(&task->sighand->siglock);
404 * If the task is already STOPPED, set JOBCTL_TRAP_STOP and
405 * TRAPPING, and kick it so that it transits to TRACED. TRAPPING
406 * will be cleared if the child completes the transition or any
407 * event which clears the group stop states happens. We'll wait
408 * for the transition to complete before returning from this
411 * This hides STOPPED -> RUNNING -> TRACED transition from the
412 * attaching thread but a different thread in the same group can
413 * still observe the transient RUNNING state. IOW, if another
414 * thread's WNOHANG wait(2) on the stopped tracee races against
415 * ATTACH, the wait(2) may fail due to the transient RUNNING.
417 * The following task_is_stopped() test is safe as both transitions
418 * in and out of STOPPED are protected by siglock.
420 if (task_is_stopped(task) &&
421 task_set_jobctl_pending(task, JOBCTL_TRAP_STOP | JOBCTL_TRAPPING))
422 signal_wake_up_state(task, __TASK_STOPPED);
424 spin_unlock(&task->sighand->siglock);
428 write_unlock_irq(&tasklist_lock);
430 mutex_unlock(&task->signal->cred_guard_mutex);
434 * We do not bother to change retval or clear JOBCTL_TRAPPING
435 * if wait_on_bit() was interrupted by SIGKILL. The tracer will
436 * not return to user-mode, it will exit and clear this bit in
437 * __ptrace_unlink() if it wasn't already cleared by the tracee;
438 * and until then nobody can ptrace this task.
440 wait_on_bit(&task->jobctl, JOBCTL_TRAPPING_BIT, TASK_KILLABLE);
441 proc_ptrace_connector(task, PTRACE_ATTACH);
448 * ptrace_traceme -- helper for PTRACE_TRACEME
450 * Performs checks and sets PT_PTRACED.
451 * Should be used by all ptrace implementations for PTRACE_TRACEME.
453 static int ptrace_traceme(void)
457 write_lock_irq(&tasklist_lock);
458 /* Are we already being traced? */
459 if (!current->ptrace) {
460 ret = security_ptrace_traceme(current->parent);
462 * Check PF_EXITING to ensure ->real_parent has not passed
463 * exit_ptrace(). Otherwise we don't report the error but
464 * pretend ->real_parent untraces us right after return.
466 if (!ret && !(current->real_parent->flags & PF_EXITING)) {
467 current->ptrace = PT_PTRACED;
468 ptrace_link(current, current->real_parent);
471 write_unlock_irq(&tasklist_lock);
477 * Called with irqs disabled, returns true if childs should reap themselves.
479 static int ignoring_children(struct sighand_struct *sigh)
482 spin_lock(&sigh->siglock);
483 ret = (sigh->action[SIGCHLD-1].sa.sa_handler == SIG_IGN) ||
484 (sigh->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT);
485 spin_unlock(&sigh->siglock);
490 * Called with tasklist_lock held for writing.
491 * Unlink a traced task, and clean it up if it was a traced zombie.
492 * Return true if it needs to be reaped with release_task().
493 * (We can't call release_task() here because we already hold tasklist_lock.)
495 * If it's a zombie, our attachedness prevented normal parent notification
496 * or self-reaping. Do notification now if it would have happened earlier.
497 * If it should reap itself, return true.
499 * If it's our own child, there is no notification to do. But if our normal
500 * children self-reap, then this child was prevented by ptrace and we must
501 * reap it now, in that case we must also wake up sub-threads sleeping in
504 static bool __ptrace_detach(struct task_struct *tracer, struct task_struct *p)
510 if (p->exit_state != EXIT_ZOMBIE)
513 dead = !thread_group_leader(p);
515 if (!dead && thread_group_empty(p)) {
516 if (!same_thread_group(p->real_parent, tracer))
517 dead = do_notify_parent(p, p->exit_signal);
518 else if (ignoring_children(tracer->sighand)) {
519 __wake_up_parent(p, tracer);
523 /* Mark it as in the process of being reaped. */
525 p->exit_state = EXIT_DEAD;
529 static int ptrace_detach(struct task_struct *child, unsigned int data)
531 if (!valid_signal(data))
534 /* Architecture-specific hardware disable .. */
535 ptrace_disable(child);
537 write_lock_irq(&tasklist_lock);
539 * We rely on ptrace_freeze_traced(). It can't be killed and
540 * untraced by another thread, it can't be a zombie.
542 WARN_ON(!child->ptrace || child->exit_state);
544 * tasklist_lock avoids the race with wait_task_stopped(), see
545 * the comment in ptrace_resume().
547 child->exit_code = data;
548 __ptrace_detach(current, child);
549 write_unlock_irq(&tasklist_lock);
551 proc_ptrace_connector(child, PTRACE_DETACH);
557 * Detach all tasks we were using ptrace on. Called with tasklist held
560 void exit_ptrace(struct task_struct *tracer, struct list_head *dead)
562 struct task_struct *p, *n;
564 list_for_each_entry_safe(p, n, &tracer->ptraced, ptrace_entry) {
565 if (unlikely(p->ptrace & PT_EXITKILL))
566 send_sig_info(SIGKILL, SEND_SIG_PRIV, p);
568 if (__ptrace_detach(tracer, p))
569 list_add(&p->ptrace_entry, dead);
573 int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len)
579 int this_len, retval;
581 this_len = (len > sizeof(buf)) ? sizeof(buf) : len;
582 retval = ptrace_access_vm(tsk, src, buf, this_len, FOLL_FORCE);
589 if (copy_to_user(dst, buf, retval))
599 int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len)
605 int this_len, retval;
607 this_len = (len > sizeof(buf)) ? sizeof(buf) : len;
608 if (copy_from_user(buf, src, this_len))
610 retval = ptrace_access_vm(tsk, dst, buf, this_len,
611 FOLL_FORCE | FOLL_WRITE);
625 static int ptrace_setoptions(struct task_struct *child, unsigned long data)
629 if (data & ~(unsigned long)PTRACE_O_MASK)
632 if (unlikely(data & PTRACE_O_SUSPEND_SECCOMP)) {
633 if (!IS_ENABLED(CONFIG_CHECKPOINT_RESTORE) ||
634 !IS_ENABLED(CONFIG_SECCOMP))
637 if (!capable(CAP_SYS_ADMIN))
640 if (seccomp_mode(¤t->seccomp) != SECCOMP_MODE_DISABLED ||
641 current->ptrace & PT_SUSPEND_SECCOMP)
645 /* Avoid intermediate state when all opts are cleared */
646 flags = child->ptrace;
647 flags &= ~(PTRACE_O_MASK << PT_OPT_FLAG_SHIFT);
648 flags |= (data << PT_OPT_FLAG_SHIFT);
649 child->ptrace = flags;
654 static int ptrace_getsiginfo(struct task_struct *child, siginfo_t *info)
659 if (lock_task_sighand(child, &flags)) {
661 if (likely(child->last_siginfo != NULL)) {
662 copy_siginfo(info, child->last_siginfo);
665 unlock_task_sighand(child, &flags);
670 static int ptrace_setsiginfo(struct task_struct *child, const siginfo_t *info)
675 if (lock_task_sighand(child, &flags)) {
677 if (likely(child->last_siginfo != NULL)) {
678 copy_siginfo(child->last_siginfo, info);
681 unlock_task_sighand(child, &flags);
686 static int ptrace_peek_siginfo(struct task_struct *child,
690 struct ptrace_peeksiginfo_args arg;
691 struct sigpending *pending;
695 ret = copy_from_user(&arg, (void __user *) addr,
696 sizeof(struct ptrace_peeksiginfo_args));
700 if (arg.flags & ~PTRACE_PEEKSIGINFO_SHARED)
701 return -EINVAL; /* unknown flags */
706 if (arg.flags & PTRACE_PEEKSIGINFO_SHARED)
707 pending = &child->signal->shared_pending;
709 pending = &child->pending;
711 for (i = 0; i < arg.nr; ) {
713 s32 off = arg.off + i;
715 spin_lock_irq(&child->sighand->siglock);
716 list_for_each_entry(q, &pending->list, list) {
718 copy_siginfo(&info, &q->info);
722 spin_unlock_irq(&child->sighand->siglock);
724 if (off >= 0) /* beyond the end of the list */
728 if (unlikely(in_compat_syscall())) {
729 compat_siginfo_t __user *uinfo = compat_ptr(data);
731 if (copy_siginfo_to_user32(uinfo, &info)) {
739 siginfo_t __user *uinfo = (siginfo_t __user *) data;
741 if (copy_siginfo_to_user(uinfo, &info)) {
747 data += sizeof(siginfo_t);
750 if (signal_pending(current))
762 #ifdef PTRACE_SINGLESTEP
763 #define is_singlestep(request) ((request) == PTRACE_SINGLESTEP)
765 #define is_singlestep(request) 0
768 #ifdef PTRACE_SINGLEBLOCK
769 #define is_singleblock(request) ((request) == PTRACE_SINGLEBLOCK)
771 #define is_singleblock(request) 0
775 #define is_sysemu_singlestep(request) ((request) == PTRACE_SYSEMU_SINGLESTEP)
777 #define is_sysemu_singlestep(request) 0
780 static int ptrace_resume(struct task_struct *child, long request,
785 if (!valid_signal(data))
788 if (request == PTRACE_SYSCALL)
789 set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
791 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
793 #ifdef TIF_SYSCALL_EMU
794 if (request == PTRACE_SYSEMU || request == PTRACE_SYSEMU_SINGLESTEP)
795 set_tsk_thread_flag(child, TIF_SYSCALL_EMU);
797 clear_tsk_thread_flag(child, TIF_SYSCALL_EMU);
800 if (is_singleblock(request)) {
801 if (unlikely(!arch_has_block_step()))
803 user_enable_block_step(child);
804 } else if (is_singlestep(request) || is_sysemu_singlestep(request)) {
805 if (unlikely(!arch_has_single_step()))
807 user_enable_single_step(child);
809 user_disable_single_step(child);
813 * Change ->exit_code and ->state under siglock to avoid the race
814 * with wait_task_stopped() in between; a non-zero ->exit_code will
815 * wrongly look like another report from tracee.
817 * Note that we need siglock even if ->exit_code == data and/or this
818 * status was not reported yet, the new status must not be cleared by
819 * wait_task_stopped() after resume.
821 * If data == 0 we do not care if wait_task_stopped() reports the old
822 * status and clears the code too; this can't race with the tracee, it
823 * takes siglock after resume.
825 need_siglock = data && !thread_group_empty(current);
827 spin_lock_irq(&child->sighand->siglock);
828 child->exit_code = data;
829 wake_up_state(child, __TASK_TRACED);
831 spin_unlock_irq(&child->sighand->siglock);
836 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
838 static const struct user_regset *
839 find_regset(const struct user_regset_view *view, unsigned int type)
841 const struct user_regset *regset;
844 for (n = 0; n < view->n; ++n) {
845 regset = view->regsets + n;
846 if (regset->core_note_type == type)
853 static int ptrace_regset(struct task_struct *task, int req, unsigned int type,
856 const struct user_regset_view *view = task_user_regset_view(task);
857 const struct user_regset *regset = find_regset(view, type);
860 if (!regset || (kiov->iov_len % regset->size) != 0)
863 regset_no = regset - view->regsets;
864 kiov->iov_len = min(kiov->iov_len,
865 (__kernel_size_t) (regset->n * regset->size));
867 if (req == PTRACE_GETREGSET)
868 return copy_regset_to_user(task, view, regset_no, 0,
869 kiov->iov_len, kiov->iov_base);
871 return copy_regset_from_user(task, view, regset_no, 0,
872 kiov->iov_len, kiov->iov_base);
876 * This is declared in linux/regset.h and defined in machine-dependent
877 * code. We put the export here, near the primary machine-neutral use,
878 * to ensure no machine forgets it.
880 EXPORT_SYMBOL_GPL(task_user_regset_view);
883 int ptrace_request(struct task_struct *child, long request,
884 unsigned long addr, unsigned long data)
886 bool seized = child->ptrace & PT_SEIZED;
888 siginfo_t siginfo, *si;
889 void __user *datavp = (void __user *) data;
890 unsigned long __user *datalp = datavp;
894 case PTRACE_PEEKTEXT:
895 case PTRACE_PEEKDATA:
896 return generic_ptrace_peekdata(child, addr, data);
897 case PTRACE_POKETEXT:
898 case PTRACE_POKEDATA:
899 return generic_ptrace_pokedata(child, addr, data);
901 #ifdef PTRACE_OLDSETOPTIONS
902 case PTRACE_OLDSETOPTIONS:
904 case PTRACE_SETOPTIONS:
905 ret = ptrace_setoptions(child, data);
907 case PTRACE_GETEVENTMSG:
908 ret = put_user(child->ptrace_message, datalp);
911 case PTRACE_PEEKSIGINFO:
912 ret = ptrace_peek_siginfo(child, addr, data);
915 case PTRACE_GETSIGINFO:
916 ret = ptrace_getsiginfo(child, &siginfo);
918 ret = copy_siginfo_to_user(datavp, &siginfo);
921 case PTRACE_SETSIGINFO:
922 ret = copy_siginfo_from_user(&siginfo, datavp);
924 ret = ptrace_setsiginfo(child, &siginfo);
927 case PTRACE_GETSIGMASK:
928 if (addr != sizeof(sigset_t)) {
933 if (copy_to_user(datavp, &child->blocked, sizeof(sigset_t)))
940 case PTRACE_SETSIGMASK: {
943 if (addr != sizeof(sigset_t)) {
948 if (copy_from_user(&new_set, datavp, sizeof(sigset_t))) {
953 sigdelsetmask(&new_set, sigmask(SIGKILL)|sigmask(SIGSTOP));
956 * Every thread does recalc_sigpending() after resume, so
957 * retarget_shared_pending() and recalc_sigpending() are not
960 spin_lock_irq(&child->sighand->siglock);
961 child->blocked = new_set;
962 spin_unlock_irq(&child->sighand->siglock);
968 case PTRACE_INTERRUPT:
970 * Stop tracee without any side-effect on signal or job
971 * control. At least one trap is guaranteed to happen
972 * after this request. If @child is already trapped, the
973 * current trap is not disturbed and another trap will
974 * happen after the current trap is ended with PTRACE_CONT.
976 * The actual trap might not be PTRACE_EVENT_STOP trap but
977 * the pending condition is cleared regardless.
979 if (unlikely(!seized || !lock_task_sighand(child, &flags)))
983 * INTERRUPT doesn't disturb existing trap sans one
984 * exception. If ptracer issued LISTEN for the current
985 * STOP, this INTERRUPT should clear LISTEN and re-trap
988 if (likely(task_set_jobctl_pending(child, JOBCTL_TRAP_STOP)))
989 ptrace_signal_wake_up(child, child->jobctl & JOBCTL_LISTENING);
991 unlock_task_sighand(child, &flags);
997 * Listen for events. Tracee must be in STOP. It's not
998 * resumed per-se but is not considered to be in TRACED by
999 * wait(2) or ptrace(2). If an async event (e.g. group
1000 * stop state change) happens, tracee will enter STOP trap
1001 * again. Alternatively, ptracer can issue INTERRUPT to
1002 * finish listening and re-trap tracee into STOP.
1004 if (unlikely(!seized || !lock_task_sighand(child, &flags)))
1007 si = child->last_siginfo;
1008 if (likely(si && (si->si_code >> 8) == PTRACE_EVENT_STOP)) {
1009 child->jobctl |= JOBCTL_LISTENING;
1011 * If NOTIFY is set, it means event happened between
1012 * start of this trap and now. Trigger re-trap.
1014 if (child->jobctl & JOBCTL_TRAP_NOTIFY)
1015 ptrace_signal_wake_up(child, true);
1018 unlock_task_sighand(child, &flags);
1021 case PTRACE_DETACH: /* detach a process that was attached. */
1022 ret = ptrace_detach(child, data);
1025 #ifdef CONFIG_BINFMT_ELF_FDPIC
1026 case PTRACE_GETFDPIC: {
1027 struct mm_struct *mm = get_task_mm(child);
1028 unsigned long tmp = 0;
1035 case PTRACE_GETFDPIC_EXEC:
1036 tmp = mm->context.exec_fdpic_loadmap;
1038 case PTRACE_GETFDPIC_INTERP:
1039 tmp = mm->context.interp_fdpic_loadmap;
1046 ret = put_user(tmp, datalp);
1051 #ifdef PTRACE_SINGLESTEP
1052 case PTRACE_SINGLESTEP:
1054 #ifdef PTRACE_SINGLEBLOCK
1055 case PTRACE_SINGLEBLOCK:
1057 #ifdef PTRACE_SYSEMU
1059 case PTRACE_SYSEMU_SINGLESTEP:
1061 case PTRACE_SYSCALL:
1063 return ptrace_resume(child, request, data);
1066 if (child->exit_state) /* already dead */
1068 return ptrace_resume(child, request, SIGKILL);
1070 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
1071 case PTRACE_GETREGSET:
1072 case PTRACE_SETREGSET: {
1074 struct iovec __user *uiov = datavp;
1076 if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov)))
1079 if (__get_user(kiov.iov_base, &uiov->iov_base) ||
1080 __get_user(kiov.iov_len, &uiov->iov_len))
1083 ret = ptrace_regset(child, request, addr, &kiov);
1085 ret = __put_user(kiov.iov_len, &uiov->iov_len);
1090 case PTRACE_SECCOMP_GET_FILTER:
1091 ret = seccomp_get_filter(child, addr, datavp);
1094 case PTRACE_SECCOMP_GET_METADATA:
1095 ret = seccomp_get_metadata(child, addr, datavp);
1105 #ifndef arch_ptrace_attach
1106 #define arch_ptrace_attach(child) do { } while (0)
1109 SYSCALL_DEFINE4(ptrace, long, request, long, pid, unsigned long, addr,
1110 unsigned long, data)
1112 struct task_struct *child;
1115 if (request == PTRACE_TRACEME) {
1116 ret = ptrace_traceme();
1118 arch_ptrace_attach(current);
1122 child = find_get_task_by_vpid(pid);
1128 if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) {
1129 ret = ptrace_attach(child, request, addr, data);
1131 * Some architectures need to do book-keeping after
1135 arch_ptrace_attach(child);
1136 goto out_put_task_struct;
1139 ret = ptrace_check_attach(child, request == PTRACE_KILL ||
1140 request == PTRACE_INTERRUPT);
1142 goto out_put_task_struct;
1144 ret = arch_ptrace(child, request, addr, data);
1145 if (ret || request != PTRACE_DETACH)
1146 ptrace_unfreeze_traced(child);
1148 out_put_task_struct:
1149 put_task_struct(child);
1154 int generic_ptrace_peekdata(struct task_struct *tsk, unsigned long addr,
1160 copied = ptrace_access_vm(tsk, addr, &tmp, sizeof(tmp), FOLL_FORCE);
1161 if (copied != sizeof(tmp))
1163 return put_user(tmp, (unsigned long __user *)data);
1166 int generic_ptrace_pokedata(struct task_struct *tsk, unsigned long addr,
1171 copied = ptrace_access_vm(tsk, addr, &data, sizeof(data),
1172 FOLL_FORCE | FOLL_WRITE);
1173 return (copied == sizeof(data)) ? 0 : -EIO;
1176 #if defined CONFIG_COMPAT
1178 int compat_ptrace_request(struct task_struct *child, compat_long_t request,
1179 compat_ulong_t addr, compat_ulong_t data)
1181 compat_ulong_t __user *datap = compat_ptr(data);
1182 compat_ulong_t word;
1187 case PTRACE_PEEKTEXT:
1188 case PTRACE_PEEKDATA:
1189 ret = ptrace_access_vm(child, addr, &word, sizeof(word),
1191 if (ret != sizeof(word))
1194 ret = put_user(word, datap);
1197 case PTRACE_POKETEXT:
1198 case PTRACE_POKEDATA:
1199 ret = ptrace_access_vm(child, addr, &data, sizeof(data),
1200 FOLL_FORCE | FOLL_WRITE);
1201 ret = (ret != sizeof(data) ? -EIO : 0);
1204 case PTRACE_GETEVENTMSG:
1205 ret = put_user((compat_ulong_t) child->ptrace_message, datap);
1208 case PTRACE_GETSIGINFO:
1209 ret = ptrace_getsiginfo(child, &siginfo);
1211 ret = copy_siginfo_to_user32(
1212 (struct compat_siginfo __user *) datap,
1216 case PTRACE_SETSIGINFO:
1217 ret = copy_siginfo_from_user32(
1218 &siginfo, (struct compat_siginfo __user *) datap);
1220 ret = ptrace_setsiginfo(child, &siginfo);
1222 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
1223 case PTRACE_GETREGSET:
1224 case PTRACE_SETREGSET:
1227 struct compat_iovec __user *uiov =
1228 (struct compat_iovec __user *) datap;
1232 if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov)))
1235 if (__get_user(ptr, &uiov->iov_base) ||
1236 __get_user(len, &uiov->iov_len))
1239 kiov.iov_base = compat_ptr(ptr);
1242 ret = ptrace_regset(child, request, addr, &kiov);
1244 ret = __put_user(kiov.iov_len, &uiov->iov_len);
1250 ret = ptrace_request(child, request, addr, data);
1256 COMPAT_SYSCALL_DEFINE4(ptrace, compat_long_t, request, compat_long_t, pid,
1257 compat_long_t, addr, compat_long_t, data)
1259 struct task_struct *child;
1262 if (request == PTRACE_TRACEME) {
1263 ret = ptrace_traceme();
1267 child = find_get_task_by_vpid(pid);
1273 if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) {
1274 ret = ptrace_attach(child, request, addr, data);
1276 * Some architectures need to do book-keeping after
1280 arch_ptrace_attach(child);
1281 goto out_put_task_struct;
1284 ret = ptrace_check_attach(child, request == PTRACE_KILL ||
1285 request == PTRACE_INTERRUPT);
1287 ret = compat_arch_ptrace(child, request, addr, data);
1288 if (ret || request != PTRACE_DETACH)
1289 ptrace_unfreeze_traced(child);
1292 out_put_task_struct:
1293 put_task_struct(child);
1297 #endif /* CONFIG_COMPAT */