bnx2x: Allow management traffic after boot from SAN
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / kernel / ptrace.c
blob1599157336a6c2be56037a510b7c2c28648201b8
1 /*
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.
8 */
10 #include <linux/capability.h>
11 #include <linux/export.h>
12 #include <linux/sched.h>
13 #include <linux/errno.h>
14 #include <linux/mm.h>
15 #include <linux/highmem.h>
16 #include <linux/pagemap.h>
17 #include <linux/ptrace.h>
18 #include <linux/security.h>
19 #include <linux/signal.h>
20 #include <linux/audit.h>
21 #include <linux/pid_namespace.h>
22 #include <linux/syscalls.h>
23 #include <linux/uaccess.h>
24 #include <linux/regset.h>
25 #include <linux/hw_breakpoint.h>
26 #include <linux/cn_proc.h>
29 static int ptrace_trapping_sleep_fn(void *flags)
31 schedule();
32 return 0;
36 * ptrace a task: make the debugger its new parent and
37 * move it to the ptrace list.
39 * Must be called with the tasklist lock write-held.
41 void __ptrace_link(struct task_struct *child, struct task_struct *new_parent)
43 BUG_ON(!list_empty(&child->ptrace_entry));
44 list_add(&child->ptrace_entry, &new_parent->ptraced);
45 child->parent = new_parent;
48 /**
49 * __ptrace_unlink - unlink ptracee and restore its execution state
50 * @child: ptracee to be unlinked
52 * Remove @child from the ptrace list, move it back to the original parent,
53 * and restore the execution state so that it conforms to the group stop
54 * state.
56 * Unlinking can happen via two paths - explicit PTRACE_DETACH or ptracer
57 * exiting. For PTRACE_DETACH, unless the ptracee has been killed between
58 * ptrace_check_attach() and here, it's guaranteed to be in TASK_TRACED.
59 * If the ptracer is exiting, the ptracee can be in any state.
61 * After detach, the ptracee should be in a state which conforms to the
62 * group stop. If the group is stopped or in the process of stopping, the
63 * ptracee should be put into TASK_STOPPED; otherwise, it should be woken
64 * up from TASK_TRACED.
66 * If the ptracee is in TASK_TRACED and needs to be moved to TASK_STOPPED,
67 * it goes through TRACED -> RUNNING -> STOPPED transition which is similar
68 * to but in the opposite direction of what happens while attaching to a
69 * stopped task. However, in this direction, the intermediate RUNNING
70 * state is not hidden even from the current ptracer and if it immediately
71 * re-attaches and performs a WNOHANG wait(2), it may fail.
73 * CONTEXT:
74 * write_lock_irq(tasklist_lock)
76 void __ptrace_unlink(struct task_struct *child)
78 BUG_ON(!child->ptrace);
80 child->ptrace = 0;
81 child->parent = child->real_parent;
82 list_del_init(&child->ptrace_entry);
84 spin_lock(&child->sighand->siglock);
87 * Clear all pending traps and TRAPPING. TRAPPING should be
88 * cleared regardless of JOBCTL_STOP_PENDING. Do it explicitly.
90 task_clear_jobctl_pending(child, JOBCTL_TRAP_MASK);
91 task_clear_jobctl_trapping(child);
94 * Reinstate JOBCTL_STOP_PENDING if group stop is in effect and
95 * @child isn't dead.
97 if (!(child->flags & PF_EXITING) &&
98 (child->signal->flags & SIGNAL_STOP_STOPPED ||
99 child->signal->group_stop_count)) {
100 child->jobctl |= JOBCTL_STOP_PENDING;
103 * This is only possible if this thread was cloned by the
104 * traced task running in the stopped group, set the signal
105 * for the future reports.
106 * FIXME: we should change ptrace_init_task() to handle this
107 * case.
109 if (!(child->jobctl & JOBCTL_STOP_SIGMASK))
110 child->jobctl |= SIGSTOP;
114 * If transition to TASK_STOPPED is pending or in TASK_TRACED, kick
115 * @child in the butt. Note that @resume should be used iff @child
116 * is in TASK_TRACED; otherwise, we might unduly disrupt
117 * TASK_KILLABLE sleeps.
119 if (child->jobctl & JOBCTL_STOP_PENDING || task_is_traced(child))
120 signal_wake_up(child, task_is_traced(child));
122 spin_unlock(&child->sighand->siglock);
126 * ptrace_check_attach - check whether ptracee is ready for ptrace operation
127 * @child: ptracee to check for
128 * @ignore_state: don't check whether @child is currently %TASK_TRACED
130 * Check whether @child is being ptraced by %current and ready for further
131 * ptrace operations. If @ignore_state is %false, @child also should be in
132 * %TASK_TRACED state and on return the child is guaranteed to be traced
133 * and not executing. If @ignore_state is %true, @child can be in any
134 * state.
136 * CONTEXT:
137 * Grabs and releases tasklist_lock and @child->sighand->siglock.
139 * RETURNS:
140 * 0 on success, -ESRCH if %child is not ready.
142 int ptrace_check_attach(struct task_struct *child, bool ignore_state)
144 int ret = -ESRCH;
147 * We take the read lock around doing both checks to close a
148 * possible race where someone else was tracing our child and
149 * detached between these two checks. After this locked check,
150 * we are sure that this is our traced child and that can only
151 * be changed by us so it's not changing right after this.
153 read_lock(&tasklist_lock);
154 if ((child->ptrace & PT_PTRACED) && child->parent == current) {
156 * child->sighand can't be NULL, release_task()
157 * does ptrace_unlink() before __exit_signal().
159 spin_lock_irq(&child->sighand->siglock);
160 WARN_ON_ONCE(task_is_stopped(child));
161 if (ignore_state || (task_is_traced(child) &&
162 !(child->jobctl & JOBCTL_LISTENING)))
163 ret = 0;
164 spin_unlock_irq(&child->sighand->siglock);
166 read_unlock(&tasklist_lock);
168 if (!ret && !ignore_state)
169 ret = wait_task_inactive(child, TASK_TRACED) ? 0 : -ESRCH;
171 /* All systems go.. */
172 return ret;
175 static int ptrace_has_cap(struct user_namespace *ns, unsigned int mode)
177 if (mode & PTRACE_MODE_NOAUDIT)
178 return has_ns_capability_noaudit(current, ns, CAP_SYS_PTRACE);
179 else
180 return has_ns_capability(current, ns, CAP_SYS_PTRACE);
183 /* Returns 0 on success, -errno on denial. */
184 static int __ptrace_may_access(struct task_struct *task, unsigned int mode)
186 const struct cred *cred = current_cred(), *tcred;
188 /* May we inspect the given task?
189 * This check is used both for attaching with ptrace
190 * and for allowing access to sensitive information in /proc.
192 * ptrace_attach denies several cases that /proc allows
193 * because setting up the necessary parent/child relationship
194 * or halting the specified task is impossible.
196 int dumpable = 0;
197 /* Don't let security modules deny introspection */
198 if (task == current)
199 return 0;
200 rcu_read_lock();
201 tcred = __task_cred(task);
202 if (uid_eq(cred->uid, tcred->euid) &&
203 uid_eq(cred->uid, tcred->suid) &&
204 uid_eq(cred->uid, tcred->uid) &&
205 gid_eq(cred->gid, tcred->egid) &&
206 gid_eq(cred->gid, tcred->sgid) &&
207 gid_eq(cred->gid, tcred->gid))
208 goto ok;
209 if (ptrace_has_cap(tcred->user_ns, mode))
210 goto ok;
211 rcu_read_unlock();
212 return -EPERM;
214 rcu_read_unlock();
215 smp_rmb();
216 if (task->mm)
217 dumpable = get_dumpable(task->mm);
218 rcu_read_lock();
219 if (!dumpable && !ptrace_has_cap(__task_cred(task)->user_ns, mode)) {
220 rcu_read_unlock();
221 return -EPERM;
223 rcu_read_unlock();
225 return security_ptrace_access_check(task, mode);
228 bool ptrace_may_access(struct task_struct *task, unsigned int mode)
230 int err;
231 task_lock(task);
232 err = __ptrace_may_access(task, mode);
233 task_unlock(task);
234 return !err;
237 static int ptrace_attach(struct task_struct *task, long request,
238 unsigned long addr,
239 unsigned long flags)
241 bool seize = (request == PTRACE_SEIZE);
242 int retval;
244 retval = -EIO;
245 if (seize) {
246 if (addr != 0)
247 goto out;
248 if (flags & ~(unsigned long)PTRACE_O_MASK)
249 goto out;
250 flags = PT_PTRACED | PT_SEIZED | (flags << PT_OPT_FLAG_SHIFT);
251 } else {
252 flags = PT_PTRACED;
255 audit_ptrace(task);
257 retval = -EPERM;
258 if (unlikely(task->flags & PF_KTHREAD))
259 goto out;
260 if (same_thread_group(task, current))
261 goto out;
264 * Protect exec's credential calculations against our interference;
265 * SUID, SGID and LSM creds get determined differently
266 * under ptrace.
268 retval = -ERESTARTNOINTR;
269 if (mutex_lock_interruptible(&task->signal->cred_guard_mutex))
270 goto out;
272 task_lock(task);
273 retval = __ptrace_may_access(task, PTRACE_MODE_ATTACH);
274 task_unlock(task);
275 if (retval)
276 goto unlock_creds;
278 write_lock_irq(&tasklist_lock);
279 retval = -EPERM;
280 if (unlikely(task->exit_state))
281 goto unlock_tasklist;
282 if (task->ptrace)
283 goto unlock_tasklist;
285 if (seize)
286 flags |= PT_SEIZED;
287 rcu_read_lock();
288 if (ns_capable(__task_cred(task)->user_ns, CAP_SYS_PTRACE))
289 flags |= PT_PTRACE_CAP;
290 rcu_read_unlock();
291 task->ptrace = flags;
293 __ptrace_link(task, current);
295 /* SEIZE doesn't trap tracee on attach */
296 if (!seize)
297 send_sig_info(SIGSTOP, SEND_SIG_FORCED, task);
299 spin_lock(&task->sighand->siglock);
302 * If the task is already STOPPED, set JOBCTL_TRAP_STOP and
303 * TRAPPING, and kick it so that it transits to TRACED. TRAPPING
304 * will be cleared if the child completes the transition or any
305 * event which clears the group stop states happens. We'll wait
306 * for the transition to complete before returning from this
307 * function.
309 * This hides STOPPED -> RUNNING -> TRACED transition from the
310 * attaching thread but a different thread in the same group can
311 * still observe the transient RUNNING state. IOW, if another
312 * thread's WNOHANG wait(2) on the stopped tracee races against
313 * ATTACH, the wait(2) may fail due to the transient RUNNING.
315 * The following task_is_stopped() test is safe as both transitions
316 * in and out of STOPPED are protected by siglock.
318 if (task_is_stopped(task) &&
319 task_set_jobctl_pending(task, JOBCTL_TRAP_STOP | JOBCTL_TRAPPING))
320 signal_wake_up(task, 1);
322 spin_unlock(&task->sighand->siglock);
324 retval = 0;
325 unlock_tasklist:
326 write_unlock_irq(&tasklist_lock);
327 unlock_creds:
328 mutex_unlock(&task->signal->cred_guard_mutex);
329 out:
330 if (!retval) {
331 wait_on_bit(&task->jobctl, JOBCTL_TRAPPING_BIT,
332 ptrace_trapping_sleep_fn, TASK_UNINTERRUPTIBLE);
333 proc_ptrace_connector(task, PTRACE_ATTACH);
336 return retval;
340 * ptrace_traceme -- helper for PTRACE_TRACEME
342 * Performs checks and sets PT_PTRACED.
343 * Should be used by all ptrace implementations for PTRACE_TRACEME.
345 static int ptrace_traceme(void)
347 int ret = -EPERM;
349 write_lock_irq(&tasklist_lock);
350 /* Are we already being traced? */
351 if (!current->ptrace) {
352 ret = security_ptrace_traceme(current->parent);
354 * Check PF_EXITING to ensure ->real_parent has not passed
355 * exit_ptrace(). Otherwise we don't report the error but
356 * pretend ->real_parent untraces us right after return.
358 if (!ret && !(current->real_parent->flags & PF_EXITING)) {
359 current->ptrace = PT_PTRACED;
360 __ptrace_link(current, current->real_parent);
363 write_unlock_irq(&tasklist_lock);
365 return ret;
369 * Called with irqs disabled, returns true if childs should reap themselves.
371 static int ignoring_children(struct sighand_struct *sigh)
373 int ret;
374 spin_lock(&sigh->siglock);
375 ret = (sigh->action[SIGCHLD-1].sa.sa_handler == SIG_IGN) ||
376 (sigh->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT);
377 spin_unlock(&sigh->siglock);
378 return ret;
382 * Called with tasklist_lock held for writing.
383 * Unlink a traced task, and clean it up if it was a traced zombie.
384 * Return true if it needs to be reaped with release_task().
385 * (We can't call release_task() here because we already hold tasklist_lock.)
387 * If it's a zombie, our attachedness prevented normal parent notification
388 * or self-reaping. Do notification now if it would have happened earlier.
389 * If it should reap itself, return true.
391 * If it's our own child, there is no notification to do. But if our normal
392 * children self-reap, then this child was prevented by ptrace and we must
393 * reap it now, in that case we must also wake up sub-threads sleeping in
394 * do_wait().
396 static bool __ptrace_detach(struct task_struct *tracer, struct task_struct *p)
398 bool dead;
400 __ptrace_unlink(p);
402 if (p->exit_state != EXIT_ZOMBIE)
403 return false;
405 dead = !thread_group_leader(p);
407 if (!dead && thread_group_empty(p)) {
408 if (!same_thread_group(p->real_parent, tracer))
409 dead = do_notify_parent(p, p->exit_signal);
410 else if (ignoring_children(tracer->sighand)) {
411 __wake_up_parent(p, tracer);
412 dead = true;
415 /* Mark it as in the process of being reaped. */
416 if (dead)
417 p->exit_state = EXIT_DEAD;
418 return dead;
421 static int ptrace_detach(struct task_struct *child, unsigned int data)
423 bool dead = false;
425 if (!valid_signal(data))
426 return -EIO;
428 /* Architecture-specific hardware disable .. */
429 ptrace_disable(child);
430 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
432 write_lock_irq(&tasklist_lock);
434 * This child can be already killed. Make sure de_thread() or
435 * our sub-thread doing do_wait() didn't do release_task() yet.
437 if (child->ptrace) {
438 child->exit_code = data;
439 dead = __ptrace_detach(current, child);
441 write_unlock_irq(&tasklist_lock);
443 proc_ptrace_connector(child, PTRACE_DETACH);
444 if (unlikely(dead))
445 release_task(child);
447 return 0;
451 * Detach all tasks we were using ptrace on. Called with tasklist held
452 * for writing, and returns with it held too. But note it can release
453 * and reacquire the lock.
455 void exit_ptrace(struct task_struct *tracer)
456 __releases(&tasklist_lock)
457 __acquires(&tasklist_lock)
459 struct task_struct *p, *n;
460 LIST_HEAD(ptrace_dead);
462 if (likely(list_empty(&tracer->ptraced)))
463 return;
465 list_for_each_entry_safe(p, n, &tracer->ptraced, ptrace_entry) {
466 if (unlikely(p->ptrace & PT_EXITKILL))
467 send_sig_info(SIGKILL, SEND_SIG_FORCED, p);
469 if (__ptrace_detach(tracer, p))
470 list_add(&p->ptrace_entry, &ptrace_dead);
473 write_unlock_irq(&tasklist_lock);
474 BUG_ON(!list_empty(&tracer->ptraced));
476 list_for_each_entry_safe(p, n, &ptrace_dead, ptrace_entry) {
477 list_del_init(&p->ptrace_entry);
478 release_task(p);
481 write_lock_irq(&tasklist_lock);
484 int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len)
486 int copied = 0;
488 while (len > 0) {
489 char buf[128];
490 int this_len, retval;
492 this_len = (len > sizeof(buf)) ? sizeof(buf) : len;
493 retval = access_process_vm(tsk, src, buf, this_len, 0);
494 if (!retval) {
495 if (copied)
496 break;
497 return -EIO;
499 if (copy_to_user(dst, buf, retval))
500 return -EFAULT;
501 copied += retval;
502 src += retval;
503 dst += retval;
504 len -= retval;
506 return copied;
509 int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len)
511 int copied = 0;
513 while (len > 0) {
514 char buf[128];
515 int this_len, retval;
517 this_len = (len > sizeof(buf)) ? sizeof(buf) : len;
518 if (copy_from_user(buf, src, this_len))
519 return -EFAULT;
520 retval = access_process_vm(tsk, dst, buf, this_len, 1);
521 if (!retval) {
522 if (copied)
523 break;
524 return -EIO;
526 copied += retval;
527 src += retval;
528 dst += retval;
529 len -= retval;
531 return copied;
534 static int ptrace_setoptions(struct task_struct *child, unsigned long data)
536 unsigned flags;
538 if (data & ~(unsigned long)PTRACE_O_MASK)
539 return -EINVAL;
541 /* Avoid intermediate state when all opts are cleared */
542 flags = child->ptrace;
543 flags &= ~(PTRACE_O_MASK << PT_OPT_FLAG_SHIFT);
544 flags |= (data << PT_OPT_FLAG_SHIFT);
545 child->ptrace = flags;
547 return 0;
550 static int ptrace_getsiginfo(struct task_struct *child, siginfo_t *info)
552 unsigned long flags;
553 int error = -ESRCH;
555 if (lock_task_sighand(child, &flags)) {
556 error = -EINVAL;
557 if (likely(child->last_siginfo != NULL)) {
558 *info = *child->last_siginfo;
559 error = 0;
561 unlock_task_sighand(child, &flags);
563 return error;
566 static int ptrace_setsiginfo(struct task_struct *child, const siginfo_t *info)
568 unsigned long flags;
569 int error = -ESRCH;
571 if (lock_task_sighand(child, &flags)) {
572 error = -EINVAL;
573 if (likely(child->last_siginfo != NULL)) {
574 *child->last_siginfo = *info;
575 error = 0;
577 unlock_task_sighand(child, &flags);
579 return error;
583 #ifdef PTRACE_SINGLESTEP
584 #define is_singlestep(request) ((request) == PTRACE_SINGLESTEP)
585 #else
586 #define is_singlestep(request) 0
587 #endif
589 #ifdef PTRACE_SINGLEBLOCK
590 #define is_singleblock(request) ((request) == PTRACE_SINGLEBLOCK)
591 #else
592 #define is_singleblock(request) 0
593 #endif
595 #ifdef PTRACE_SYSEMU
596 #define is_sysemu_singlestep(request) ((request) == PTRACE_SYSEMU_SINGLESTEP)
597 #else
598 #define is_sysemu_singlestep(request) 0
599 #endif
601 static int ptrace_resume(struct task_struct *child, long request,
602 unsigned long data)
604 if (!valid_signal(data))
605 return -EIO;
607 if (request == PTRACE_SYSCALL)
608 set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
609 else
610 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
612 #ifdef TIF_SYSCALL_EMU
613 if (request == PTRACE_SYSEMU || request == PTRACE_SYSEMU_SINGLESTEP)
614 set_tsk_thread_flag(child, TIF_SYSCALL_EMU);
615 else
616 clear_tsk_thread_flag(child, TIF_SYSCALL_EMU);
617 #endif
619 if (is_singleblock(request)) {
620 if (unlikely(!arch_has_block_step()))
621 return -EIO;
622 user_enable_block_step(child);
623 } else if (is_singlestep(request) || is_sysemu_singlestep(request)) {
624 if (unlikely(!arch_has_single_step()))
625 return -EIO;
626 user_enable_single_step(child);
627 } else {
628 user_disable_single_step(child);
631 child->exit_code = data;
632 wake_up_state(child, __TASK_TRACED);
634 return 0;
637 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
639 static const struct user_regset *
640 find_regset(const struct user_regset_view *view, unsigned int type)
642 const struct user_regset *regset;
643 int n;
645 for (n = 0; n < view->n; ++n) {
646 regset = view->regsets + n;
647 if (regset->core_note_type == type)
648 return regset;
651 return NULL;
654 static int ptrace_regset(struct task_struct *task, int req, unsigned int type,
655 struct iovec *kiov)
657 const struct user_regset_view *view = task_user_regset_view(task);
658 const struct user_regset *regset = find_regset(view, type);
659 int regset_no;
661 if (!regset || (kiov->iov_len % regset->size) != 0)
662 return -EINVAL;
664 regset_no = regset - view->regsets;
665 kiov->iov_len = min(kiov->iov_len,
666 (__kernel_size_t) (regset->n * regset->size));
668 if (req == PTRACE_GETREGSET)
669 return copy_regset_to_user(task, view, regset_no, 0,
670 kiov->iov_len, kiov->iov_base);
671 else
672 return copy_regset_from_user(task, view, regset_no, 0,
673 kiov->iov_len, kiov->iov_base);
676 #endif
678 int ptrace_request(struct task_struct *child, long request,
679 unsigned long addr, unsigned long data)
681 bool seized = child->ptrace & PT_SEIZED;
682 int ret = -EIO;
683 siginfo_t siginfo, *si;
684 void __user *datavp = (void __user *) data;
685 unsigned long __user *datalp = datavp;
686 unsigned long flags;
688 switch (request) {
689 case PTRACE_PEEKTEXT:
690 case PTRACE_PEEKDATA:
691 return generic_ptrace_peekdata(child, addr, data);
692 case PTRACE_POKETEXT:
693 case PTRACE_POKEDATA:
694 return generic_ptrace_pokedata(child, addr, data);
696 #ifdef PTRACE_OLDSETOPTIONS
697 case PTRACE_OLDSETOPTIONS:
698 #endif
699 case PTRACE_SETOPTIONS:
700 ret = ptrace_setoptions(child, data);
701 break;
702 case PTRACE_GETEVENTMSG:
703 ret = put_user(child->ptrace_message, datalp);
704 break;
706 case PTRACE_GETSIGINFO:
707 ret = ptrace_getsiginfo(child, &siginfo);
708 if (!ret)
709 ret = copy_siginfo_to_user(datavp, &siginfo);
710 break;
712 case PTRACE_SETSIGINFO:
713 if (copy_from_user(&siginfo, datavp, sizeof siginfo))
714 ret = -EFAULT;
715 else
716 ret = ptrace_setsiginfo(child, &siginfo);
717 break;
719 case PTRACE_INTERRUPT:
721 * Stop tracee without any side-effect on signal or job
722 * control. At least one trap is guaranteed to happen
723 * after this request. If @child is already trapped, the
724 * current trap is not disturbed and another trap will
725 * happen after the current trap is ended with PTRACE_CONT.
727 * The actual trap might not be PTRACE_EVENT_STOP trap but
728 * the pending condition is cleared regardless.
730 if (unlikely(!seized || !lock_task_sighand(child, &flags)))
731 break;
734 * INTERRUPT doesn't disturb existing trap sans one
735 * exception. If ptracer issued LISTEN for the current
736 * STOP, this INTERRUPT should clear LISTEN and re-trap
737 * tracee into STOP.
739 if (likely(task_set_jobctl_pending(child, JOBCTL_TRAP_STOP)))
740 signal_wake_up(child, child->jobctl & JOBCTL_LISTENING);
742 unlock_task_sighand(child, &flags);
743 ret = 0;
744 break;
746 case PTRACE_LISTEN:
748 * Listen for events. Tracee must be in STOP. It's not
749 * resumed per-se but is not considered to be in TRACED by
750 * wait(2) or ptrace(2). If an async event (e.g. group
751 * stop state change) happens, tracee will enter STOP trap
752 * again. Alternatively, ptracer can issue INTERRUPT to
753 * finish listening and re-trap tracee into STOP.
755 if (unlikely(!seized || !lock_task_sighand(child, &flags)))
756 break;
758 si = child->last_siginfo;
759 if (likely(si && (si->si_code >> 8) == PTRACE_EVENT_STOP)) {
760 child->jobctl |= JOBCTL_LISTENING;
762 * If NOTIFY is set, it means event happened between
763 * start of this trap and now. Trigger re-trap.
765 if (child->jobctl & JOBCTL_TRAP_NOTIFY)
766 signal_wake_up(child, true);
767 ret = 0;
769 unlock_task_sighand(child, &flags);
770 break;
772 case PTRACE_DETACH: /* detach a process that was attached. */
773 ret = ptrace_detach(child, data);
774 break;
776 #ifdef CONFIG_BINFMT_ELF_FDPIC
777 case PTRACE_GETFDPIC: {
778 struct mm_struct *mm = get_task_mm(child);
779 unsigned long tmp = 0;
781 ret = -ESRCH;
782 if (!mm)
783 break;
785 switch (addr) {
786 case PTRACE_GETFDPIC_EXEC:
787 tmp = mm->context.exec_fdpic_loadmap;
788 break;
789 case PTRACE_GETFDPIC_INTERP:
790 tmp = mm->context.interp_fdpic_loadmap;
791 break;
792 default:
793 break;
795 mmput(mm);
797 ret = put_user(tmp, datalp);
798 break;
800 #endif
802 #ifdef PTRACE_SINGLESTEP
803 case PTRACE_SINGLESTEP:
804 #endif
805 #ifdef PTRACE_SINGLEBLOCK
806 case PTRACE_SINGLEBLOCK:
807 #endif
808 #ifdef PTRACE_SYSEMU
809 case PTRACE_SYSEMU:
810 case PTRACE_SYSEMU_SINGLESTEP:
811 #endif
812 case PTRACE_SYSCALL:
813 case PTRACE_CONT:
814 return ptrace_resume(child, request, data);
816 case PTRACE_KILL:
817 if (child->exit_state) /* already dead */
818 return 0;
819 return ptrace_resume(child, request, SIGKILL);
821 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
822 case PTRACE_GETREGSET:
823 case PTRACE_SETREGSET:
825 struct iovec kiov;
826 struct iovec __user *uiov = datavp;
828 if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov)))
829 return -EFAULT;
831 if (__get_user(kiov.iov_base, &uiov->iov_base) ||
832 __get_user(kiov.iov_len, &uiov->iov_len))
833 return -EFAULT;
835 ret = ptrace_regset(child, request, addr, &kiov);
836 if (!ret)
837 ret = __put_user(kiov.iov_len, &uiov->iov_len);
838 break;
840 #endif
841 default:
842 break;
845 return ret;
848 static struct task_struct *ptrace_get_task_struct(pid_t pid)
850 struct task_struct *child;
852 rcu_read_lock();
853 child = find_task_by_vpid(pid);
854 if (child)
855 get_task_struct(child);
856 rcu_read_unlock();
858 if (!child)
859 return ERR_PTR(-ESRCH);
860 return child;
863 #ifndef arch_ptrace_attach
864 #define arch_ptrace_attach(child) do { } while (0)
865 #endif
867 SYSCALL_DEFINE4(ptrace, long, request, long, pid, unsigned long, addr,
868 unsigned long, data)
870 struct task_struct *child;
871 long ret;
873 if (request == PTRACE_TRACEME) {
874 ret = ptrace_traceme();
875 if (!ret)
876 arch_ptrace_attach(current);
877 goto out;
880 child = ptrace_get_task_struct(pid);
881 if (IS_ERR(child)) {
882 ret = PTR_ERR(child);
883 goto out;
886 if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) {
887 ret = ptrace_attach(child, request, addr, data);
889 * Some architectures need to do book-keeping after
890 * a ptrace attach.
892 if (!ret)
893 arch_ptrace_attach(child);
894 goto out_put_task_struct;
897 ret = ptrace_check_attach(child, request == PTRACE_KILL ||
898 request == PTRACE_INTERRUPT);
899 if (ret < 0)
900 goto out_put_task_struct;
902 ret = arch_ptrace(child, request, addr, data);
904 out_put_task_struct:
905 put_task_struct(child);
906 out:
907 return ret;
910 int generic_ptrace_peekdata(struct task_struct *tsk, unsigned long addr,
911 unsigned long data)
913 unsigned long tmp;
914 int copied;
916 copied = access_process_vm(tsk, addr, &tmp, sizeof(tmp), 0);
917 if (copied != sizeof(tmp))
918 return -EIO;
919 return put_user(tmp, (unsigned long __user *)data);
922 int generic_ptrace_pokedata(struct task_struct *tsk, unsigned long addr,
923 unsigned long data)
925 int copied;
927 copied = access_process_vm(tsk, addr, &data, sizeof(data), 1);
928 return (copied == sizeof(data)) ? 0 : -EIO;
931 #if defined CONFIG_COMPAT
932 #include <linux/compat.h>
934 int compat_ptrace_request(struct task_struct *child, compat_long_t request,
935 compat_ulong_t addr, compat_ulong_t data)
937 compat_ulong_t __user *datap = compat_ptr(data);
938 compat_ulong_t word;
939 siginfo_t siginfo;
940 int ret;
942 switch (request) {
943 case PTRACE_PEEKTEXT:
944 case PTRACE_PEEKDATA:
945 ret = access_process_vm(child, addr, &word, sizeof(word), 0);
946 if (ret != sizeof(word))
947 ret = -EIO;
948 else
949 ret = put_user(word, datap);
950 break;
952 case PTRACE_POKETEXT:
953 case PTRACE_POKEDATA:
954 ret = access_process_vm(child, addr, &data, sizeof(data), 1);
955 ret = (ret != sizeof(data) ? -EIO : 0);
956 break;
958 case PTRACE_GETEVENTMSG:
959 ret = put_user((compat_ulong_t) child->ptrace_message, datap);
960 break;
962 case PTRACE_GETSIGINFO:
963 ret = ptrace_getsiginfo(child, &siginfo);
964 if (!ret)
965 ret = copy_siginfo_to_user32(
966 (struct compat_siginfo __user *) datap,
967 &siginfo);
968 break;
970 case PTRACE_SETSIGINFO:
971 memset(&siginfo, 0, sizeof siginfo);
972 if (copy_siginfo_from_user32(
973 &siginfo, (struct compat_siginfo __user *) datap))
974 ret = -EFAULT;
975 else
976 ret = ptrace_setsiginfo(child, &siginfo);
977 break;
978 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
979 case PTRACE_GETREGSET:
980 case PTRACE_SETREGSET:
982 struct iovec kiov;
983 struct compat_iovec __user *uiov =
984 (struct compat_iovec __user *) datap;
985 compat_uptr_t ptr;
986 compat_size_t len;
988 if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov)))
989 return -EFAULT;
991 if (__get_user(ptr, &uiov->iov_base) ||
992 __get_user(len, &uiov->iov_len))
993 return -EFAULT;
995 kiov.iov_base = compat_ptr(ptr);
996 kiov.iov_len = len;
998 ret = ptrace_regset(child, request, addr, &kiov);
999 if (!ret)
1000 ret = __put_user(kiov.iov_len, &uiov->iov_len);
1001 break;
1003 #endif
1005 default:
1006 ret = ptrace_request(child, request, addr, data);
1009 return ret;
1012 asmlinkage long compat_sys_ptrace(compat_long_t request, compat_long_t pid,
1013 compat_long_t addr, compat_long_t data)
1015 struct task_struct *child;
1016 long ret;
1018 if (request == PTRACE_TRACEME) {
1019 ret = ptrace_traceme();
1020 goto out;
1023 child = ptrace_get_task_struct(pid);
1024 if (IS_ERR(child)) {
1025 ret = PTR_ERR(child);
1026 goto out;
1029 if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) {
1030 ret = ptrace_attach(child, request, addr, data);
1032 * Some architectures need to do book-keeping after
1033 * a ptrace attach.
1035 if (!ret)
1036 arch_ptrace_attach(child);
1037 goto out_put_task_struct;
1040 ret = ptrace_check_attach(child, request == PTRACE_KILL ||
1041 request == PTRACE_INTERRUPT);
1042 if (!ret)
1043 ret = compat_arch_ptrace(child, request, addr, data);
1045 out_put_task_struct:
1046 put_task_struct(child);
1047 out:
1048 return ret;
1050 #endif /* CONFIG_COMPAT */
1052 #ifdef CONFIG_HAVE_HW_BREAKPOINT
1053 int ptrace_get_breakpoints(struct task_struct *tsk)
1055 if (atomic_inc_not_zero(&tsk->ptrace_bp_refcnt))
1056 return 0;
1058 return -1;
1061 void ptrace_put_breakpoints(struct task_struct *tsk)
1063 if (atomic_dec_and_test(&tsk->ptrace_bp_refcnt))
1064 flush_ptrace_hw_breakpoint(tsk);
1066 #endif /* CONFIG_HAVE_HW_BREAKPOINT */