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)
81 __ptrace_link(child, new_parent, current_cred());
85 * __ptrace_unlink - unlink ptracee and restore its execution state
86 * @child: ptracee to be unlinked
88 * Remove @child from the ptrace list, move it back to the original parent,
89 * and restore the execution state so that it conforms to the group stop
92 * Unlinking can happen via two paths - explicit PTRACE_DETACH or ptracer
93 * exiting. For PTRACE_DETACH, unless the ptracee has been killed between
94 * ptrace_check_attach() and here, it's guaranteed to be in TASK_TRACED.
95 * If the ptracer is exiting, the ptracee can be in any state.
97 * After detach, the ptracee should be in a state which conforms to the
98 * group stop. If the group is stopped or in the process of stopping, the
99 * ptracee should be put into TASK_STOPPED; otherwise, it should be woken
100 * up from TASK_TRACED.
102 * If the ptracee is in TASK_TRACED and needs to be moved to TASK_STOPPED,
103 * it goes through TRACED -> RUNNING -> STOPPED transition which is similar
104 * to but in the opposite direction of what happens while attaching to a
105 * stopped task. However, in this direction, the intermediate RUNNING
106 * state is not hidden even from the current ptracer and if it immediately
107 * re-attaches and performs a WNOHANG wait(2), it may fail.
110 * write_lock_irq(tasklist_lock)
112 void __ptrace_unlink(struct task_struct *child)
114 const struct cred *old_cred;
115 BUG_ON(!child->ptrace);
117 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
119 child->parent = child->real_parent;
120 list_del_init(&child->ptrace_entry);
121 old_cred = child->ptracer_cred;
122 child->ptracer_cred = NULL;
125 spin_lock(&child->sighand->siglock);
128 * Clear all pending traps and TRAPPING. TRAPPING should be
129 * cleared regardless of JOBCTL_STOP_PENDING. Do it explicitly.
131 task_clear_jobctl_pending(child, JOBCTL_TRAP_MASK);
132 task_clear_jobctl_trapping(child);
135 * Reinstate JOBCTL_STOP_PENDING if group stop is in effect and
138 if (!(child->flags & PF_EXITING) &&
139 (child->signal->flags & SIGNAL_STOP_STOPPED ||
140 child->signal->group_stop_count)) {
141 child->jobctl |= JOBCTL_STOP_PENDING;
144 * This is only possible if this thread was cloned by the
145 * traced task running in the stopped group, set the signal
146 * for the future reports.
147 * FIXME: we should change ptrace_init_task() to handle this
150 if (!(child->jobctl & JOBCTL_STOP_SIGMASK))
151 child->jobctl |= SIGSTOP;
155 * If transition to TASK_STOPPED is pending or in TASK_TRACED, kick
156 * @child in the butt. Note that @resume should be used iff @child
157 * is in TASK_TRACED; otherwise, we might unduly disrupt
158 * TASK_KILLABLE sleeps.
160 if (child->jobctl & JOBCTL_STOP_PENDING || task_is_traced(child))
161 ptrace_signal_wake_up(child, true);
163 spin_unlock(&child->sighand->siglock);
166 static bool looks_like_a_spurious_pid(struct task_struct *task)
168 if (task->exit_code != ((PTRACE_EVENT_EXEC << 8) | SIGTRAP))
171 if (task_pid_vnr(task) == task->ptrace_message)
174 * The tracee changed its pid but the PTRACE_EVENT_EXEC event
175 * was not wait()'ed, most probably debugger targets the old
176 * leader which was destroyed in de_thread().
181 /* Ensure that nothing can wake it up, even SIGKILL */
182 static bool ptrace_freeze_traced(struct task_struct *task)
186 /* Lockless, nobody but us can set this flag */
187 if (task->jobctl & JOBCTL_LISTENING)
190 spin_lock_irq(&task->sighand->siglock);
191 if (task_is_traced(task) && !looks_like_a_spurious_pid(task) &&
192 !__fatal_signal_pending(task)) {
193 task->state = __TASK_TRACED;
196 spin_unlock_irq(&task->sighand->siglock);
201 static void ptrace_unfreeze_traced(struct task_struct *task)
203 if (task->state != __TASK_TRACED)
206 WARN_ON(!task->ptrace || task->parent != current);
209 * PTRACE_LISTEN can allow ptrace_trap_notify to wake us up remotely.
210 * Recheck state under the lock to close this race.
212 spin_lock_irq(&task->sighand->siglock);
213 if (task->state == __TASK_TRACED) {
214 if (__fatal_signal_pending(task))
215 wake_up_state(task, __TASK_TRACED);
217 task->state = TASK_TRACED;
219 spin_unlock_irq(&task->sighand->siglock);
223 * ptrace_check_attach - check whether ptracee is ready for ptrace operation
224 * @child: ptracee to check for
225 * @ignore_state: don't check whether @child is currently %TASK_TRACED
227 * Check whether @child is being ptraced by %current and ready for further
228 * ptrace operations. If @ignore_state is %false, @child also should be in
229 * %TASK_TRACED state and on return the child is guaranteed to be traced
230 * and not executing. If @ignore_state is %true, @child can be in any
234 * Grabs and releases tasklist_lock and @child->sighand->siglock.
237 * 0 on success, -ESRCH if %child is not ready.
239 static int ptrace_check_attach(struct task_struct *child, bool ignore_state)
244 * We take the read lock around doing both checks to close a
245 * possible race where someone else was tracing our child and
246 * detached between these two checks. After this locked check,
247 * we are sure that this is our traced child and that can only
248 * be changed by us so it's not changing right after this.
250 read_lock(&tasklist_lock);
251 if (child->ptrace && child->parent == current) {
252 WARN_ON(child->state == __TASK_TRACED);
254 * child->sighand can't be NULL, release_task()
255 * does ptrace_unlink() before __exit_signal().
257 if (ignore_state || ptrace_freeze_traced(child))
260 read_unlock(&tasklist_lock);
262 if (!ret && !ignore_state) {
263 if (!wait_task_inactive(child, __TASK_TRACED)) {
265 * This can only happen if may_ptrace_stop() fails and
266 * ptrace_stop() changes ->state back to TASK_RUNNING,
267 * so we should not worry about leaking __TASK_TRACED.
269 WARN_ON(child->state == __TASK_TRACED);
277 static bool ptrace_has_cap(const struct cred *cred, struct user_namespace *ns,
282 if (mode & PTRACE_MODE_NOAUDIT)
283 ret = security_capable(cred, ns, CAP_SYS_PTRACE);
285 ret = security_capable(cred, ns, CAP_SYS_PTRACE);
290 /* Returns 0 on success, -errno on denial. */
291 static int __ptrace_may_access(struct task_struct *task, unsigned int mode)
293 const struct cred *cred = current_cred(), *tcred;
294 struct mm_struct *mm;
298 if (!(mode & PTRACE_MODE_FSCREDS) == !(mode & PTRACE_MODE_REALCREDS)) {
299 WARN(1, "denying ptrace access check without PTRACE_MODE_*CREDS\n");
303 /* May we inspect the given task?
304 * This check is used both for attaching with ptrace
305 * and for allowing access to sensitive information in /proc.
307 * ptrace_attach denies several cases that /proc allows
308 * because setting up the necessary parent/child relationship
309 * or halting the specified task is impossible.
312 /* Don't let security modules deny introspection */
313 if (same_thread_group(task, current))
316 if (mode & PTRACE_MODE_FSCREDS) {
317 caller_uid = cred->fsuid;
318 caller_gid = cred->fsgid;
321 * Using the euid would make more sense here, but something
322 * in userland might rely on the old behavior, and this
323 * shouldn't be a security problem since
324 * PTRACE_MODE_REALCREDS implies that the caller explicitly
325 * used a syscall that requests access to another process
326 * (and not a filesystem syscall to procfs).
328 caller_uid = cred->uid;
329 caller_gid = cred->gid;
331 tcred = __task_cred(task);
332 if (uid_eq(caller_uid, tcred->euid) &&
333 uid_eq(caller_uid, tcred->suid) &&
334 uid_eq(caller_uid, tcred->uid) &&
335 gid_eq(caller_gid, tcred->egid) &&
336 gid_eq(caller_gid, tcred->sgid) &&
337 gid_eq(caller_gid, tcred->gid))
339 if (ptrace_has_cap(cred, tcred->user_ns, mode))
346 * If a task drops privileges and becomes nondumpable (through a syscall
347 * like setresuid()) while we are trying to access it, we must ensure
348 * that the dumpability is read after the credentials; otherwise,
349 * we may be able to attach to a task that we shouldn't be able to
350 * attach to (as if the task had dropped privileges without becoming
352 * Pairs with a write barrier in commit_creds().
357 ((get_dumpable(mm) != SUID_DUMP_USER) &&
358 !ptrace_has_cap(cred, mm->user_ns, mode)))
361 return security_ptrace_access_check(task, mode);
364 bool ptrace_may_access(struct task_struct *task, unsigned int mode)
368 err = __ptrace_may_access(task, mode);
373 static int check_ptrace_options(unsigned long data)
375 if (data & ~(unsigned long)PTRACE_O_MASK)
378 if (unlikely(data & PTRACE_O_SUSPEND_SECCOMP)) {
379 if (!IS_ENABLED(CONFIG_CHECKPOINT_RESTORE) ||
380 !IS_ENABLED(CONFIG_SECCOMP))
383 if (!capable(CAP_SYS_ADMIN))
386 if (seccomp_mode(¤t->seccomp) != SECCOMP_MODE_DISABLED ||
387 current->ptrace & PT_SUSPEND_SECCOMP)
393 static int ptrace_attach(struct task_struct *task, long request,
397 bool seize = (request == PTRACE_SEIZE);
405 * This duplicates the check in check_ptrace_options() because
406 * ptrace_attach() and ptrace_setoptions() have historically
407 * used different error codes for unknown ptrace options.
409 if (flags & ~(unsigned long)PTRACE_O_MASK)
411 retval = check_ptrace_options(flags);
414 flags = PT_PTRACED | PT_SEIZED | (flags << PT_OPT_FLAG_SHIFT);
422 if (unlikely(task->flags & PF_KTHREAD))
424 if (same_thread_group(task, current))
428 * Protect exec's credential calculations against our interference;
429 * SUID, SGID and LSM creds get determined differently
432 retval = -ERESTARTNOINTR;
433 if (mutex_lock_interruptible(&task->signal->cred_guard_mutex))
437 retval = __ptrace_may_access(task, PTRACE_MODE_ATTACH_REALCREDS);
442 write_lock_irq(&tasklist_lock);
444 if (unlikely(task->exit_state))
445 goto unlock_tasklist;
447 goto unlock_tasklist;
451 task->ptrace = flags;
453 ptrace_link(task, current);
455 /* SEIZE doesn't trap tracee on attach */
457 send_sig_info(SIGSTOP, SEND_SIG_FORCED, task);
459 spin_lock(&task->sighand->siglock);
462 * If the task is already STOPPED, set JOBCTL_TRAP_STOP and
463 * TRAPPING, and kick it so that it transits to TRACED. TRAPPING
464 * will be cleared if the child completes the transition or any
465 * event which clears the group stop states happens. We'll wait
466 * for the transition to complete before returning from this
469 * This hides STOPPED -> RUNNING -> TRACED transition from the
470 * attaching thread but a different thread in the same group can
471 * still observe the transient RUNNING state. IOW, if another
472 * thread's WNOHANG wait(2) on the stopped tracee races against
473 * ATTACH, the wait(2) may fail due to the transient RUNNING.
475 * The following task_is_stopped() test is safe as both transitions
476 * in and out of STOPPED are protected by siglock.
478 if (task_is_stopped(task) &&
479 task_set_jobctl_pending(task, JOBCTL_TRAP_STOP | JOBCTL_TRAPPING))
480 signal_wake_up_state(task, __TASK_STOPPED);
482 spin_unlock(&task->sighand->siglock);
486 write_unlock_irq(&tasklist_lock);
488 mutex_unlock(&task->signal->cred_guard_mutex);
492 * We do not bother to change retval or clear JOBCTL_TRAPPING
493 * if wait_on_bit() was interrupted by SIGKILL. The tracer will
494 * not return to user-mode, it will exit and clear this bit in
495 * __ptrace_unlink() if it wasn't already cleared by the tracee;
496 * and until then nobody can ptrace this task.
498 wait_on_bit(&task->jobctl, JOBCTL_TRAPPING_BIT, TASK_KILLABLE);
499 proc_ptrace_connector(task, PTRACE_ATTACH);
506 * ptrace_traceme -- helper for PTRACE_TRACEME
508 * Performs checks and sets PT_PTRACED.
509 * Should be used by all ptrace implementations for PTRACE_TRACEME.
511 static int ptrace_traceme(void)
515 write_lock_irq(&tasklist_lock);
516 /* Are we already being traced? */
517 if (!current->ptrace) {
518 ret = security_ptrace_traceme(current->parent);
520 * Check PF_EXITING to ensure ->real_parent has not passed
521 * exit_ptrace(). Otherwise we don't report the error but
522 * pretend ->real_parent untraces us right after return.
524 if (!ret && !(current->real_parent->flags & PF_EXITING)) {
525 current->ptrace = PT_PTRACED;
526 ptrace_link(current, current->real_parent);
529 write_unlock_irq(&tasklist_lock);
535 * Called with irqs disabled, returns true if childs should reap themselves.
537 static int ignoring_children(struct sighand_struct *sigh)
540 spin_lock(&sigh->siglock);
541 ret = (sigh->action[SIGCHLD-1].sa.sa_handler == SIG_IGN) ||
542 (sigh->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT);
543 spin_unlock(&sigh->siglock);
548 * Called with tasklist_lock held for writing.
549 * Unlink a traced task, and clean it up if it was a traced zombie.
550 * Return true if it needs to be reaped with release_task().
551 * (We can't call release_task() here because we already hold tasklist_lock.)
553 * If it's a zombie, our attachedness prevented normal parent notification
554 * or self-reaping. Do notification now if it would have happened earlier.
555 * If it should reap itself, return true.
557 * If it's our own child, there is no notification to do. But if our normal
558 * children self-reap, then this child was prevented by ptrace and we must
559 * reap it now, in that case we must also wake up sub-threads sleeping in
562 static bool __ptrace_detach(struct task_struct *tracer, struct task_struct *p)
568 if (p->exit_state != EXIT_ZOMBIE)
571 dead = !thread_group_leader(p);
573 if (!dead && thread_group_empty(p)) {
574 if (!same_thread_group(p->real_parent, tracer))
575 dead = do_notify_parent(p, p->exit_signal);
576 else if (ignoring_children(tracer->sighand)) {
577 __wake_up_parent(p, tracer);
581 /* Mark it as in the process of being reaped. */
583 p->exit_state = EXIT_DEAD;
587 static int ptrace_detach(struct task_struct *child, unsigned int data)
589 if (!valid_signal(data))
592 /* Architecture-specific hardware disable .. */
593 ptrace_disable(child);
595 write_lock_irq(&tasklist_lock);
597 * We rely on ptrace_freeze_traced(). It can't be killed and
598 * untraced by another thread, it can't be a zombie.
600 WARN_ON(!child->ptrace || child->exit_state);
602 * tasklist_lock avoids the race with wait_task_stopped(), see
603 * the comment in ptrace_resume().
605 child->exit_code = data;
606 __ptrace_detach(current, child);
607 write_unlock_irq(&tasklist_lock);
609 proc_ptrace_connector(child, PTRACE_DETACH);
615 * Detach all tasks we were using ptrace on. Called with tasklist held
618 void exit_ptrace(struct task_struct *tracer, struct list_head *dead)
620 struct task_struct *p, *n;
622 list_for_each_entry_safe(p, n, &tracer->ptraced, ptrace_entry) {
623 if (unlikely(p->ptrace & PT_EXITKILL))
624 send_sig_info(SIGKILL, SEND_SIG_FORCED, p);
626 if (__ptrace_detach(tracer, p))
627 list_add(&p->ptrace_entry, dead);
631 int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len)
637 int this_len, retval;
639 this_len = (len > sizeof(buf)) ? sizeof(buf) : len;
640 retval = ptrace_access_vm(tsk, src, buf, this_len, FOLL_FORCE);
647 if (copy_to_user(dst, buf, retval))
657 int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len)
663 int this_len, retval;
665 this_len = (len > sizeof(buf)) ? sizeof(buf) : len;
666 if (copy_from_user(buf, src, this_len))
668 retval = ptrace_access_vm(tsk, dst, buf, this_len,
669 FOLL_FORCE | FOLL_WRITE);
683 static int ptrace_setoptions(struct task_struct *child, unsigned long data)
688 ret = check_ptrace_options(data);
692 /* Avoid intermediate state when all opts are cleared */
693 flags = child->ptrace;
694 flags &= ~(PTRACE_O_MASK << PT_OPT_FLAG_SHIFT);
695 flags |= (data << PT_OPT_FLAG_SHIFT);
696 child->ptrace = flags;
701 static int ptrace_getsiginfo(struct task_struct *child, siginfo_t *info)
706 if (lock_task_sighand(child, &flags)) {
708 if (likely(child->last_siginfo != NULL)) {
709 *info = *child->last_siginfo;
712 unlock_task_sighand(child, &flags);
717 static int ptrace_setsiginfo(struct task_struct *child, const siginfo_t *info)
722 if (lock_task_sighand(child, &flags)) {
724 if (likely(child->last_siginfo != NULL)) {
725 *child->last_siginfo = *info;
728 unlock_task_sighand(child, &flags);
733 static int ptrace_peek_siginfo(struct task_struct *child,
737 struct ptrace_peeksiginfo_args arg;
738 struct sigpending *pending;
742 ret = copy_from_user(&arg, (void __user *) addr,
743 sizeof(struct ptrace_peeksiginfo_args));
747 if (arg.flags & ~PTRACE_PEEKSIGINFO_SHARED)
748 return -EINVAL; /* unknown flags */
753 /* Ensure arg.off fits in an unsigned long */
754 if (arg.off > ULONG_MAX)
757 if (arg.flags & PTRACE_PEEKSIGINFO_SHARED)
758 pending = &child->signal->shared_pending;
760 pending = &child->pending;
762 for (i = 0; i < arg.nr; ) {
764 unsigned long off = arg.off + i;
767 spin_lock_irq(&child->sighand->siglock);
768 list_for_each_entry(q, &pending->list, list) {
771 copy_siginfo(&info, &q->info);
775 spin_unlock_irq(&child->sighand->siglock);
777 if (!found) /* beyond the end of the list */
781 if (unlikely(in_compat_syscall())) {
782 compat_siginfo_t __user *uinfo = compat_ptr(data);
784 if (copy_siginfo_to_user32(uinfo, &info)) {
792 siginfo_t __user *uinfo = (siginfo_t __user *) data;
794 if (copy_siginfo_to_user(uinfo, &info)) {
800 data += sizeof(siginfo_t);
803 if (signal_pending(current))
815 #ifdef PTRACE_SINGLESTEP
816 #define is_singlestep(request) ((request) == PTRACE_SINGLESTEP)
818 #define is_singlestep(request) 0
821 #ifdef PTRACE_SINGLEBLOCK
822 #define is_singleblock(request) ((request) == PTRACE_SINGLEBLOCK)
824 #define is_singleblock(request) 0
828 #define is_sysemu_singlestep(request) ((request) == PTRACE_SYSEMU_SINGLESTEP)
830 #define is_sysemu_singlestep(request) 0
833 static int ptrace_resume(struct task_struct *child, long request,
838 if (!valid_signal(data))
841 if (request == PTRACE_SYSCALL)
842 set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
844 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
846 #ifdef TIF_SYSCALL_EMU
847 if (request == PTRACE_SYSEMU || request == PTRACE_SYSEMU_SINGLESTEP)
848 set_tsk_thread_flag(child, TIF_SYSCALL_EMU);
850 clear_tsk_thread_flag(child, TIF_SYSCALL_EMU);
853 if (is_singleblock(request)) {
854 if (unlikely(!arch_has_block_step()))
856 user_enable_block_step(child);
857 } else if (is_singlestep(request) || is_sysemu_singlestep(request)) {
858 if (unlikely(!arch_has_single_step()))
860 user_enable_single_step(child);
862 user_disable_single_step(child);
866 * Change ->exit_code and ->state under siglock to avoid the race
867 * with wait_task_stopped() in between; a non-zero ->exit_code will
868 * wrongly look like another report from tracee.
870 * Note that we need siglock even if ->exit_code == data and/or this
871 * status was not reported yet, the new status must not be cleared by
872 * wait_task_stopped() after resume.
874 * If data == 0 we do not care if wait_task_stopped() reports the old
875 * status and clears the code too; this can't race with the tracee, it
876 * takes siglock after resume.
878 need_siglock = data && !thread_group_empty(current);
880 spin_lock_irq(&child->sighand->siglock);
881 child->exit_code = data;
882 wake_up_state(child, __TASK_TRACED);
884 spin_unlock_irq(&child->sighand->siglock);
889 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
891 static const struct user_regset *
892 find_regset(const struct user_regset_view *view, unsigned int type)
894 const struct user_regset *regset;
897 for (n = 0; n < view->n; ++n) {
898 regset = view->regsets + n;
899 if (regset->core_note_type == type)
906 static int ptrace_regset(struct task_struct *task, int req, unsigned int type,
909 const struct user_regset_view *view = task_user_regset_view(task);
910 const struct user_regset *regset = find_regset(view, type);
913 if (!regset || (kiov->iov_len % regset->size) != 0)
916 regset_no = regset - view->regsets;
917 kiov->iov_len = min(kiov->iov_len,
918 (__kernel_size_t) (regset->n * regset->size));
920 if (req == PTRACE_GETREGSET)
921 return copy_regset_to_user(task, view, regset_no, 0,
922 kiov->iov_len, kiov->iov_base);
924 return copy_regset_from_user(task, view, regset_no, 0,
925 kiov->iov_len, kiov->iov_base);
929 * This is declared in linux/regset.h and defined in machine-dependent
930 * code. We put the export here, near the primary machine-neutral use,
931 * to ensure no machine forgets it.
933 EXPORT_SYMBOL_GPL(task_user_regset_view);
936 int ptrace_request(struct task_struct *child, long request,
937 unsigned long addr, unsigned long data)
939 bool seized = child->ptrace & PT_SEIZED;
941 siginfo_t siginfo, *si;
942 void __user *datavp = (void __user *) data;
943 unsigned long __user *datalp = datavp;
947 case PTRACE_PEEKTEXT:
948 case PTRACE_PEEKDATA:
949 return generic_ptrace_peekdata(child, addr, data);
950 case PTRACE_POKETEXT:
951 case PTRACE_POKEDATA:
952 return generic_ptrace_pokedata(child, addr, data);
954 #ifdef PTRACE_OLDSETOPTIONS
955 case PTRACE_OLDSETOPTIONS:
957 case PTRACE_SETOPTIONS:
958 ret = ptrace_setoptions(child, data);
960 case PTRACE_GETEVENTMSG:
961 ret = put_user(child->ptrace_message, datalp);
964 case PTRACE_PEEKSIGINFO:
965 ret = ptrace_peek_siginfo(child, addr, data);
968 case PTRACE_GETSIGINFO:
969 ret = ptrace_getsiginfo(child, &siginfo);
971 ret = copy_siginfo_to_user(datavp, &siginfo);
974 case PTRACE_SETSIGINFO:
975 if (copy_from_user(&siginfo, datavp, sizeof siginfo))
978 ret = ptrace_setsiginfo(child, &siginfo);
981 case PTRACE_GETSIGMASK: {
984 if (addr != sizeof(sigset_t)) {
989 if (test_tsk_restore_sigmask(child))
990 mask = &child->saved_sigmask;
992 mask = &child->blocked;
994 if (copy_to_user(datavp, mask, sizeof(sigset_t)))
1002 case PTRACE_SETSIGMASK: {
1005 if (addr != sizeof(sigset_t)) {
1010 if (copy_from_user(&new_set, datavp, sizeof(sigset_t))) {
1015 sigdelsetmask(&new_set, sigmask(SIGKILL)|sigmask(SIGSTOP));
1018 * Every thread does recalc_sigpending() after resume, so
1019 * retarget_shared_pending() and recalc_sigpending() are not
1022 spin_lock_irq(&child->sighand->siglock);
1023 child->blocked = new_set;
1024 spin_unlock_irq(&child->sighand->siglock);
1026 clear_tsk_restore_sigmask(child);
1032 case PTRACE_INTERRUPT:
1034 * Stop tracee without any side-effect on signal or job
1035 * control. At least one trap is guaranteed to happen
1036 * after this request. If @child is already trapped, the
1037 * current trap is not disturbed and another trap will
1038 * happen after the current trap is ended with PTRACE_CONT.
1040 * The actual trap might not be PTRACE_EVENT_STOP trap but
1041 * the pending condition is cleared regardless.
1043 if (unlikely(!seized || !lock_task_sighand(child, &flags)))
1047 * INTERRUPT doesn't disturb existing trap sans one
1048 * exception. If ptracer issued LISTEN for the current
1049 * STOP, this INTERRUPT should clear LISTEN and re-trap
1052 if (likely(task_set_jobctl_pending(child, JOBCTL_TRAP_STOP)))
1053 ptrace_signal_wake_up(child, child->jobctl & JOBCTL_LISTENING);
1055 unlock_task_sighand(child, &flags);
1061 * Listen for events. Tracee must be in STOP. It's not
1062 * resumed per-se but is not considered to be in TRACED by
1063 * wait(2) or ptrace(2). If an async event (e.g. group
1064 * stop state change) happens, tracee will enter STOP trap
1065 * again. Alternatively, ptracer can issue INTERRUPT to
1066 * finish listening and re-trap tracee into STOP.
1068 if (unlikely(!seized || !lock_task_sighand(child, &flags)))
1071 si = child->last_siginfo;
1072 if (likely(si && (si->si_code >> 8) == PTRACE_EVENT_STOP)) {
1073 child->jobctl |= JOBCTL_LISTENING;
1075 * If NOTIFY is set, it means event happened between
1076 * start of this trap and now. Trigger re-trap.
1078 if (child->jobctl & JOBCTL_TRAP_NOTIFY)
1079 ptrace_signal_wake_up(child, true);
1082 unlock_task_sighand(child, &flags);
1085 case PTRACE_DETACH: /* detach a process that was attached. */
1086 ret = ptrace_detach(child, data);
1089 #ifdef CONFIG_BINFMT_ELF_FDPIC
1090 case PTRACE_GETFDPIC: {
1091 struct mm_struct *mm = get_task_mm(child);
1092 unsigned long tmp = 0;
1099 case PTRACE_GETFDPIC_EXEC:
1100 tmp = mm->context.exec_fdpic_loadmap;
1102 case PTRACE_GETFDPIC_INTERP:
1103 tmp = mm->context.interp_fdpic_loadmap;
1110 ret = put_user(tmp, datalp);
1115 #ifdef PTRACE_SINGLESTEP
1116 case PTRACE_SINGLESTEP:
1118 #ifdef PTRACE_SINGLEBLOCK
1119 case PTRACE_SINGLEBLOCK:
1121 #ifdef PTRACE_SYSEMU
1123 case PTRACE_SYSEMU_SINGLESTEP:
1125 case PTRACE_SYSCALL:
1127 return ptrace_resume(child, request, data);
1130 send_sig_info(SIGKILL, SEND_SIG_NOINFO, child);
1133 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
1134 case PTRACE_GETREGSET:
1135 case PTRACE_SETREGSET: {
1137 struct iovec __user *uiov = datavp;
1139 if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov)))
1142 if (__get_user(kiov.iov_base, &uiov->iov_base) ||
1143 __get_user(kiov.iov_len, &uiov->iov_len))
1146 ret = ptrace_regset(child, request, addr, &kiov);
1148 ret = __put_user(kiov.iov_len, &uiov->iov_len);
1153 case PTRACE_SECCOMP_GET_FILTER:
1154 ret = seccomp_get_filter(child, addr, datavp);
1164 static struct task_struct *ptrace_get_task_struct(pid_t pid)
1166 struct task_struct *child;
1169 child = find_task_by_vpid(pid);
1171 get_task_struct(child);
1175 return ERR_PTR(-ESRCH);
1179 #ifndef arch_ptrace_attach
1180 #define arch_ptrace_attach(child) do { } while (0)
1183 SYSCALL_DEFINE4(ptrace, long, request, long, pid, unsigned long, addr,
1184 unsigned long, data)
1186 struct task_struct *child;
1189 if (request == PTRACE_TRACEME) {
1190 ret = ptrace_traceme();
1192 arch_ptrace_attach(current);
1196 child = ptrace_get_task_struct(pid);
1197 if (IS_ERR(child)) {
1198 ret = PTR_ERR(child);
1202 if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) {
1203 ret = ptrace_attach(child, request, addr, data);
1205 * Some architectures need to do book-keeping after
1209 arch_ptrace_attach(child);
1210 goto out_put_task_struct;
1213 ret = ptrace_check_attach(child, request == PTRACE_KILL ||
1214 request == PTRACE_INTERRUPT);
1216 goto out_put_task_struct;
1218 ret = arch_ptrace(child, request, addr, data);
1219 if (ret || request != PTRACE_DETACH)
1220 ptrace_unfreeze_traced(child);
1222 out_put_task_struct:
1223 put_task_struct(child);
1228 int generic_ptrace_peekdata(struct task_struct *tsk, unsigned long addr,
1234 copied = ptrace_access_vm(tsk, addr, &tmp, sizeof(tmp), FOLL_FORCE);
1235 if (copied != sizeof(tmp))
1237 return put_user(tmp, (unsigned long __user *)data);
1240 int generic_ptrace_pokedata(struct task_struct *tsk, unsigned long addr,
1245 copied = ptrace_access_vm(tsk, addr, &data, sizeof(data),
1246 FOLL_FORCE | FOLL_WRITE);
1247 return (copied == sizeof(data)) ? 0 : -EIO;
1250 #if defined CONFIG_COMPAT
1252 int compat_ptrace_request(struct task_struct *child, compat_long_t request,
1253 compat_ulong_t addr, compat_ulong_t data)
1255 compat_ulong_t __user *datap = compat_ptr(data);
1256 compat_ulong_t word;
1261 case PTRACE_PEEKTEXT:
1262 case PTRACE_PEEKDATA:
1263 ret = ptrace_access_vm(child, addr, &word, sizeof(word),
1265 if (ret != sizeof(word))
1268 ret = put_user(word, datap);
1271 case PTRACE_POKETEXT:
1272 case PTRACE_POKEDATA:
1273 ret = ptrace_access_vm(child, addr, &data, sizeof(data),
1274 FOLL_FORCE | FOLL_WRITE);
1275 ret = (ret != sizeof(data) ? -EIO : 0);
1278 case PTRACE_GETEVENTMSG:
1279 ret = put_user((compat_ulong_t) child->ptrace_message, datap);
1282 case PTRACE_GETSIGINFO:
1283 ret = ptrace_getsiginfo(child, &siginfo);
1285 ret = copy_siginfo_to_user32(
1286 (struct compat_siginfo __user *) datap,
1290 case PTRACE_SETSIGINFO:
1291 memset(&siginfo, 0, sizeof siginfo);
1292 if (copy_siginfo_from_user32(
1293 &siginfo, (struct compat_siginfo __user *) datap))
1296 ret = ptrace_setsiginfo(child, &siginfo);
1298 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
1299 case PTRACE_GETREGSET:
1300 case PTRACE_SETREGSET:
1303 struct compat_iovec __user *uiov =
1304 (struct compat_iovec __user *) datap;
1308 if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov)))
1311 if (__get_user(ptr, &uiov->iov_base) ||
1312 __get_user(len, &uiov->iov_len))
1315 kiov.iov_base = compat_ptr(ptr);
1318 ret = ptrace_regset(child, request, addr, &kiov);
1320 ret = __put_user(kiov.iov_len, &uiov->iov_len);
1326 ret = ptrace_request(child, request, addr, data);
1332 COMPAT_SYSCALL_DEFINE4(ptrace, compat_long_t, request, compat_long_t, pid,
1333 compat_long_t, addr, compat_long_t, data)
1335 struct task_struct *child;
1338 if (request == PTRACE_TRACEME) {
1339 ret = ptrace_traceme();
1343 child = ptrace_get_task_struct(pid);
1344 if (IS_ERR(child)) {
1345 ret = PTR_ERR(child);
1349 if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) {
1350 ret = ptrace_attach(child, request, addr, data);
1352 * Some architectures need to do book-keeping after
1356 arch_ptrace_attach(child);
1357 goto out_put_task_struct;
1360 ret = ptrace_check_attach(child, request == PTRACE_KILL ||
1361 request == PTRACE_INTERRUPT);
1363 ret = compat_arch_ptrace(child, request, addr, data);
1364 if (ret || request != PTRACE_DETACH)
1365 ptrace_unfreeze_traced(child);
1368 out_put_task_struct:
1369 put_task_struct(child);
1373 #endif /* CONFIG_COMPAT */