Merge branch 'batman-adv/next' of git://git.open-mesh.org/linux-merge
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / kernel / ptrace.c
blob2df115790cd9e1ab6a1128603697ce5b6ed255d9
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/module.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>
29 * ptrace a task: make the debugger its new parent and
30 * move it to the ptrace list.
32 * Must be called with the tasklist lock write-held.
34 void __ptrace_link(struct task_struct *child, struct task_struct *new_parent)
36 BUG_ON(!list_empty(&child->ptrace_entry));
37 list_add(&child->ptrace_entry, &new_parent->ptraced);
38 child->parent = new_parent;
41 /**
42 * __ptrace_unlink - unlink ptracee and restore its execution state
43 * @child: ptracee to be unlinked
45 * Remove @child from the ptrace list, move it back to the original parent,
46 * and restore the execution state so that it conforms to the group stop
47 * state.
49 * Unlinking can happen via two paths - explicit PTRACE_DETACH or ptracer
50 * exiting. For PTRACE_DETACH, unless the ptracee has been killed between
51 * ptrace_check_attach() and here, it's guaranteed to be in TASK_TRACED.
52 * If the ptracer is exiting, the ptracee can be in any state.
54 * After detach, the ptracee should be in a state which conforms to the
55 * group stop. If the group is stopped or in the process of stopping, the
56 * ptracee should be put into TASK_STOPPED; otherwise, it should be woken
57 * up from TASK_TRACED.
59 * If the ptracee is in TASK_TRACED and needs to be moved to TASK_STOPPED,
60 * it goes through TRACED -> RUNNING -> STOPPED transition which is similar
61 * to but in the opposite direction of what happens while attaching to a
62 * stopped task. However, in this direction, the intermediate RUNNING
63 * state is not hidden even from the current ptracer and if it immediately
64 * re-attaches and performs a WNOHANG wait(2), it may fail.
66 * CONTEXT:
67 * write_lock_irq(tasklist_lock)
69 void __ptrace_unlink(struct task_struct *child)
71 BUG_ON(!child->ptrace);
73 child->ptrace = 0;
74 child->parent = child->real_parent;
75 list_del_init(&child->ptrace_entry);
77 spin_lock(&child->sighand->siglock);
80 * Reinstate GROUP_STOP_PENDING if group stop is in effect and
81 * @child isn't dead.
83 if (!(child->flags & PF_EXITING) &&
84 (child->signal->flags & SIGNAL_STOP_STOPPED ||
85 child->signal->group_stop_count))
86 child->group_stop |= GROUP_STOP_PENDING;
89 * If transition to TASK_STOPPED is pending or in TASK_TRACED, kick
90 * @child in the butt. Note that @resume should be used iff @child
91 * is in TASK_TRACED; otherwise, we might unduly disrupt
92 * TASK_KILLABLE sleeps.
94 if (child->group_stop & GROUP_STOP_PENDING || task_is_traced(child))
95 signal_wake_up(child, task_is_traced(child));
97 spin_unlock(&child->sighand->siglock);
101 * Check that we have indeed attached to the thing..
103 int ptrace_check_attach(struct task_struct *child, int kill)
105 int ret = -ESRCH;
108 * We take the read lock around doing both checks to close a
109 * possible race where someone else was tracing our child and
110 * detached between these two checks. After this locked check,
111 * we are sure that this is our traced child and that can only
112 * be changed by us so it's not changing right after this.
114 read_lock(&tasklist_lock);
115 if ((child->ptrace & PT_PTRACED) && child->parent == current) {
117 * child->sighand can't be NULL, release_task()
118 * does ptrace_unlink() before __exit_signal().
120 spin_lock_irq(&child->sighand->siglock);
121 WARN_ON_ONCE(task_is_stopped(child));
122 if (task_is_traced(child) || kill)
123 ret = 0;
124 spin_unlock_irq(&child->sighand->siglock);
126 read_unlock(&tasklist_lock);
128 if (!ret && !kill)
129 ret = wait_task_inactive(child, TASK_TRACED) ? 0 : -ESRCH;
131 /* All systems go.. */
132 return ret;
135 int __ptrace_may_access(struct task_struct *task, unsigned int mode)
137 const struct cred *cred = current_cred(), *tcred;
139 /* May we inspect the given task?
140 * This check is used both for attaching with ptrace
141 * and for allowing access to sensitive information in /proc.
143 * ptrace_attach denies several cases that /proc allows
144 * because setting up the necessary parent/child relationship
145 * or halting the specified task is impossible.
147 int dumpable = 0;
148 /* Don't let security modules deny introspection */
149 if (task == current)
150 return 0;
151 rcu_read_lock();
152 tcred = __task_cred(task);
153 if (cred->user->user_ns == tcred->user->user_ns &&
154 (cred->uid == tcred->euid &&
155 cred->uid == tcred->suid &&
156 cred->uid == tcred->uid &&
157 cred->gid == tcred->egid &&
158 cred->gid == tcred->sgid &&
159 cred->gid == tcred->gid))
160 goto ok;
161 if (ns_capable(tcred->user->user_ns, CAP_SYS_PTRACE))
162 goto ok;
163 rcu_read_unlock();
164 return -EPERM;
166 rcu_read_unlock();
167 smp_rmb();
168 if (task->mm)
169 dumpable = get_dumpable(task->mm);
170 if (!dumpable && !task_ns_capable(task, CAP_SYS_PTRACE))
171 return -EPERM;
173 return security_ptrace_access_check(task, mode);
176 bool ptrace_may_access(struct task_struct *task, unsigned int mode)
178 int err;
179 task_lock(task);
180 err = __ptrace_may_access(task, mode);
181 task_unlock(task);
182 return !err;
185 static int ptrace_attach(struct task_struct *task)
187 bool wait_trap = false;
188 int retval;
190 audit_ptrace(task);
192 retval = -EPERM;
193 if (unlikely(task->flags & PF_KTHREAD))
194 goto out;
195 if (same_thread_group(task, current))
196 goto out;
199 * Protect exec's credential calculations against our interference;
200 * interference; SUID, SGID and LSM creds get determined differently
201 * under ptrace.
203 retval = -ERESTARTNOINTR;
204 if (mutex_lock_interruptible(&task->signal->cred_guard_mutex))
205 goto out;
207 task_lock(task);
208 retval = __ptrace_may_access(task, PTRACE_MODE_ATTACH);
209 task_unlock(task);
210 if (retval)
211 goto unlock_creds;
213 write_lock_irq(&tasklist_lock);
214 retval = -EPERM;
215 if (unlikely(task->exit_state))
216 goto unlock_tasklist;
217 if (task->ptrace)
218 goto unlock_tasklist;
220 task->ptrace = PT_PTRACED;
221 if (task_ns_capable(task, CAP_SYS_PTRACE))
222 task->ptrace |= PT_PTRACE_CAP;
224 __ptrace_link(task, current);
225 send_sig_info(SIGSTOP, SEND_SIG_FORCED, task);
227 spin_lock(&task->sighand->siglock);
230 * If the task is already STOPPED, set GROUP_STOP_PENDING and
231 * TRAPPING, and kick it so that it transits to TRACED. TRAPPING
232 * will be cleared if the child completes the transition or any
233 * event which clears the group stop states happens. We'll wait
234 * for the transition to complete before returning from this
235 * function.
237 * This hides STOPPED -> RUNNING -> TRACED transition from the
238 * attaching thread but a different thread in the same group can
239 * still observe the transient RUNNING state. IOW, if another
240 * thread's WNOHANG wait(2) on the stopped tracee races against
241 * ATTACH, the wait(2) may fail due to the transient RUNNING.
243 * The following task_is_stopped() test is safe as both transitions
244 * in and out of STOPPED are protected by siglock.
246 if (task_is_stopped(task)) {
247 task->group_stop |= GROUP_STOP_PENDING | GROUP_STOP_TRAPPING;
248 signal_wake_up(task, 1);
249 wait_trap = true;
252 spin_unlock(&task->sighand->siglock);
254 retval = 0;
255 unlock_tasklist:
256 write_unlock_irq(&tasklist_lock);
257 unlock_creds:
258 mutex_unlock(&task->signal->cred_guard_mutex);
259 out:
260 if (wait_trap)
261 wait_event(current->signal->wait_chldexit,
262 !(task->group_stop & GROUP_STOP_TRAPPING));
263 return retval;
267 * ptrace_traceme -- helper for PTRACE_TRACEME
269 * Performs checks and sets PT_PTRACED.
270 * Should be used by all ptrace implementations for PTRACE_TRACEME.
272 static int ptrace_traceme(void)
274 int ret = -EPERM;
276 write_lock_irq(&tasklist_lock);
277 /* Are we already being traced? */
278 if (!current->ptrace) {
279 ret = security_ptrace_traceme(current->parent);
281 * Check PF_EXITING to ensure ->real_parent has not passed
282 * exit_ptrace(). Otherwise we don't report the error but
283 * pretend ->real_parent untraces us right after return.
285 if (!ret && !(current->real_parent->flags & PF_EXITING)) {
286 current->ptrace = PT_PTRACED;
287 __ptrace_link(current, current->real_parent);
290 write_unlock_irq(&tasklist_lock);
292 return ret;
296 * Called with irqs disabled, returns true if childs should reap themselves.
298 static int ignoring_children(struct sighand_struct *sigh)
300 int ret;
301 spin_lock(&sigh->siglock);
302 ret = (sigh->action[SIGCHLD-1].sa.sa_handler == SIG_IGN) ||
303 (sigh->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT);
304 spin_unlock(&sigh->siglock);
305 return ret;
309 * Called with tasklist_lock held for writing.
310 * Unlink a traced task, and clean it up if it was a traced zombie.
311 * Return true if it needs to be reaped with release_task().
312 * (We can't call release_task() here because we already hold tasklist_lock.)
314 * If it's a zombie, our attachedness prevented normal parent notification
315 * or self-reaping. Do notification now if it would have happened earlier.
316 * If it should reap itself, return true.
318 * If it's our own child, there is no notification to do. But if our normal
319 * children self-reap, then this child was prevented by ptrace and we must
320 * reap it now, in that case we must also wake up sub-threads sleeping in
321 * do_wait().
323 static bool __ptrace_detach(struct task_struct *tracer, struct task_struct *p)
325 __ptrace_unlink(p);
327 if (p->exit_state == EXIT_ZOMBIE) {
328 if (!task_detached(p) && thread_group_empty(p)) {
329 if (!same_thread_group(p->real_parent, tracer))
330 do_notify_parent(p, p->exit_signal);
331 else if (ignoring_children(tracer->sighand)) {
332 __wake_up_parent(p, tracer);
333 p->exit_signal = -1;
336 if (task_detached(p)) {
337 /* Mark it as in the process of being reaped. */
338 p->exit_state = EXIT_DEAD;
339 return true;
343 return false;
346 static int ptrace_detach(struct task_struct *child, unsigned int data)
348 bool dead = false;
350 if (!valid_signal(data))
351 return -EIO;
353 /* Architecture-specific hardware disable .. */
354 ptrace_disable(child);
355 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
357 write_lock_irq(&tasklist_lock);
359 * This child can be already killed. Make sure de_thread() or
360 * our sub-thread doing do_wait() didn't do release_task() yet.
362 if (child->ptrace) {
363 child->exit_code = data;
364 dead = __ptrace_detach(current, child);
366 write_unlock_irq(&tasklist_lock);
368 if (unlikely(dead))
369 release_task(child);
371 return 0;
375 * Detach all tasks we were using ptrace on. Called with tasklist held
376 * for writing, and returns with it held too. But note it can release
377 * and reacquire the lock.
379 void exit_ptrace(struct task_struct *tracer)
380 __releases(&tasklist_lock)
381 __acquires(&tasklist_lock)
383 struct task_struct *p, *n;
384 LIST_HEAD(ptrace_dead);
386 if (likely(list_empty(&tracer->ptraced)))
387 return;
389 list_for_each_entry_safe(p, n, &tracer->ptraced, ptrace_entry) {
390 if (__ptrace_detach(tracer, p))
391 list_add(&p->ptrace_entry, &ptrace_dead);
394 write_unlock_irq(&tasklist_lock);
395 BUG_ON(!list_empty(&tracer->ptraced));
397 list_for_each_entry_safe(p, n, &ptrace_dead, ptrace_entry) {
398 list_del_init(&p->ptrace_entry);
399 release_task(p);
402 write_lock_irq(&tasklist_lock);
405 int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len)
407 int copied = 0;
409 while (len > 0) {
410 char buf[128];
411 int this_len, retval;
413 this_len = (len > sizeof(buf)) ? sizeof(buf) : len;
414 retval = access_process_vm(tsk, src, buf, this_len, 0);
415 if (!retval) {
416 if (copied)
417 break;
418 return -EIO;
420 if (copy_to_user(dst, buf, retval))
421 return -EFAULT;
422 copied += retval;
423 src += retval;
424 dst += retval;
425 len -= retval;
427 return copied;
430 int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len)
432 int copied = 0;
434 while (len > 0) {
435 char buf[128];
436 int this_len, retval;
438 this_len = (len > sizeof(buf)) ? sizeof(buf) : len;
439 if (copy_from_user(buf, src, this_len))
440 return -EFAULT;
441 retval = access_process_vm(tsk, dst, buf, this_len, 1);
442 if (!retval) {
443 if (copied)
444 break;
445 return -EIO;
447 copied += retval;
448 src += retval;
449 dst += retval;
450 len -= retval;
452 return copied;
455 static int ptrace_setoptions(struct task_struct *child, unsigned long data)
457 child->ptrace &= ~PT_TRACE_MASK;
459 if (data & PTRACE_O_TRACESYSGOOD)
460 child->ptrace |= PT_TRACESYSGOOD;
462 if (data & PTRACE_O_TRACEFORK)
463 child->ptrace |= PT_TRACE_FORK;
465 if (data & PTRACE_O_TRACEVFORK)
466 child->ptrace |= PT_TRACE_VFORK;
468 if (data & PTRACE_O_TRACECLONE)
469 child->ptrace |= PT_TRACE_CLONE;
471 if (data & PTRACE_O_TRACEEXEC)
472 child->ptrace |= PT_TRACE_EXEC;
474 if (data & PTRACE_O_TRACEVFORKDONE)
475 child->ptrace |= PT_TRACE_VFORK_DONE;
477 if (data & PTRACE_O_TRACEEXIT)
478 child->ptrace |= PT_TRACE_EXIT;
480 return (data & ~PTRACE_O_MASK) ? -EINVAL : 0;
483 static int ptrace_getsiginfo(struct task_struct *child, siginfo_t *info)
485 unsigned long flags;
486 int error = -ESRCH;
488 if (lock_task_sighand(child, &flags)) {
489 error = -EINVAL;
490 if (likely(child->last_siginfo != NULL)) {
491 *info = *child->last_siginfo;
492 error = 0;
494 unlock_task_sighand(child, &flags);
496 return error;
499 static int ptrace_setsiginfo(struct task_struct *child, const siginfo_t *info)
501 unsigned long flags;
502 int error = -ESRCH;
504 if (lock_task_sighand(child, &flags)) {
505 error = -EINVAL;
506 if (likely(child->last_siginfo != NULL)) {
507 *child->last_siginfo = *info;
508 error = 0;
510 unlock_task_sighand(child, &flags);
512 return error;
516 #ifdef PTRACE_SINGLESTEP
517 #define is_singlestep(request) ((request) == PTRACE_SINGLESTEP)
518 #else
519 #define is_singlestep(request) 0
520 #endif
522 #ifdef PTRACE_SINGLEBLOCK
523 #define is_singleblock(request) ((request) == PTRACE_SINGLEBLOCK)
524 #else
525 #define is_singleblock(request) 0
526 #endif
528 #ifdef PTRACE_SYSEMU
529 #define is_sysemu_singlestep(request) ((request) == PTRACE_SYSEMU_SINGLESTEP)
530 #else
531 #define is_sysemu_singlestep(request) 0
532 #endif
534 static int ptrace_resume(struct task_struct *child, long request,
535 unsigned long data)
537 if (!valid_signal(data))
538 return -EIO;
540 if (request == PTRACE_SYSCALL)
541 set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
542 else
543 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
545 #ifdef TIF_SYSCALL_EMU
546 if (request == PTRACE_SYSEMU || request == PTRACE_SYSEMU_SINGLESTEP)
547 set_tsk_thread_flag(child, TIF_SYSCALL_EMU);
548 else
549 clear_tsk_thread_flag(child, TIF_SYSCALL_EMU);
550 #endif
552 if (is_singleblock(request)) {
553 if (unlikely(!arch_has_block_step()))
554 return -EIO;
555 user_enable_block_step(child);
556 } else if (is_singlestep(request) || is_sysemu_singlestep(request)) {
557 if (unlikely(!arch_has_single_step()))
558 return -EIO;
559 user_enable_single_step(child);
560 } else {
561 user_disable_single_step(child);
564 child->exit_code = data;
565 wake_up_state(child, __TASK_TRACED);
567 return 0;
570 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
572 static const struct user_regset *
573 find_regset(const struct user_regset_view *view, unsigned int type)
575 const struct user_regset *regset;
576 int n;
578 for (n = 0; n < view->n; ++n) {
579 regset = view->regsets + n;
580 if (regset->core_note_type == type)
581 return regset;
584 return NULL;
587 static int ptrace_regset(struct task_struct *task, int req, unsigned int type,
588 struct iovec *kiov)
590 const struct user_regset_view *view = task_user_regset_view(task);
591 const struct user_regset *regset = find_regset(view, type);
592 int regset_no;
594 if (!regset || (kiov->iov_len % regset->size) != 0)
595 return -EINVAL;
597 regset_no = regset - view->regsets;
598 kiov->iov_len = min(kiov->iov_len,
599 (__kernel_size_t) (regset->n * regset->size));
601 if (req == PTRACE_GETREGSET)
602 return copy_regset_to_user(task, view, regset_no, 0,
603 kiov->iov_len, kiov->iov_base);
604 else
605 return copy_regset_from_user(task, view, regset_no, 0,
606 kiov->iov_len, kiov->iov_base);
609 #endif
611 int ptrace_request(struct task_struct *child, long request,
612 unsigned long addr, unsigned long data)
614 int ret = -EIO;
615 siginfo_t siginfo;
616 void __user *datavp = (void __user *) data;
617 unsigned long __user *datalp = datavp;
619 switch (request) {
620 case PTRACE_PEEKTEXT:
621 case PTRACE_PEEKDATA:
622 return generic_ptrace_peekdata(child, addr, data);
623 case PTRACE_POKETEXT:
624 case PTRACE_POKEDATA:
625 return generic_ptrace_pokedata(child, addr, data);
627 #ifdef PTRACE_OLDSETOPTIONS
628 case PTRACE_OLDSETOPTIONS:
629 #endif
630 case PTRACE_SETOPTIONS:
631 ret = ptrace_setoptions(child, data);
632 break;
633 case PTRACE_GETEVENTMSG:
634 ret = put_user(child->ptrace_message, datalp);
635 break;
637 case PTRACE_GETSIGINFO:
638 ret = ptrace_getsiginfo(child, &siginfo);
639 if (!ret)
640 ret = copy_siginfo_to_user(datavp, &siginfo);
641 break;
643 case PTRACE_SETSIGINFO:
644 if (copy_from_user(&siginfo, datavp, sizeof siginfo))
645 ret = -EFAULT;
646 else
647 ret = ptrace_setsiginfo(child, &siginfo);
648 break;
650 case PTRACE_DETACH: /* detach a process that was attached. */
651 ret = ptrace_detach(child, data);
652 break;
654 #ifdef CONFIG_BINFMT_ELF_FDPIC
655 case PTRACE_GETFDPIC: {
656 struct mm_struct *mm = get_task_mm(child);
657 unsigned long tmp = 0;
659 ret = -ESRCH;
660 if (!mm)
661 break;
663 switch (addr) {
664 case PTRACE_GETFDPIC_EXEC:
665 tmp = mm->context.exec_fdpic_loadmap;
666 break;
667 case PTRACE_GETFDPIC_INTERP:
668 tmp = mm->context.interp_fdpic_loadmap;
669 break;
670 default:
671 break;
673 mmput(mm);
675 ret = put_user(tmp, datalp);
676 break;
678 #endif
680 #ifdef PTRACE_SINGLESTEP
681 case PTRACE_SINGLESTEP:
682 #endif
683 #ifdef PTRACE_SINGLEBLOCK
684 case PTRACE_SINGLEBLOCK:
685 #endif
686 #ifdef PTRACE_SYSEMU
687 case PTRACE_SYSEMU:
688 case PTRACE_SYSEMU_SINGLESTEP:
689 #endif
690 case PTRACE_SYSCALL:
691 case PTRACE_CONT:
692 return ptrace_resume(child, request, data);
694 case PTRACE_KILL:
695 if (child->exit_state) /* already dead */
696 return 0;
697 return ptrace_resume(child, request, SIGKILL);
699 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
700 case PTRACE_GETREGSET:
701 case PTRACE_SETREGSET:
703 struct iovec kiov;
704 struct iovec __user *uiov = datavp;
706 if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov)))
707 return -EFAULT;
709 if (__get_user(kiov.iov_base, &uiov->iov_base) ||
710 __get_user(kiov.iov_len, &uiov->iov_len))
711 return -EFAULT;
713 ret = ptrace_regset(child, request, addr, &kiov);
714 if (!ret)
715 ret = __put_user(kiov.iov_len, &uiov->iov_len);
716 break;
718 #endif
719 default:
720 break;
723 return ret;
726 static struct task_struct *ptrace_get_task_struct(pid_t pid)
728 struct task_struct *child;
730 rcu_read_lock();
731 child = find_task_by_vpid(pid);
732 if (child)
733 get_task_struct(child);
734 rcu_read_unlock();
736 if (!child)
737 return ERR_PTR(-ESRCH);
738 return child;
741 #ifndef arch_ptrace_attach
742 #define arch_ptrace_attach(child) do { } while (0)
743 #endif
745 SYSCALL_DEFINE4(ptrace, long, request, long, pid, unsigned long, addr,
746 unsigned long, data)
748 struct task_struct *child;
749 long ret;
751 if (request == PTRACE_TRACEME) {
752 ret = ptrace_traceme();
753 if (!ret)
754 arch_ptrace_attach(current);
755 goto out;
758 child = ptrace_get_task_struct(pid);
759 if (IS_ERR(child)) {
760 ret = PTR_ERR(child);
761 goto out;
764 if (request == PTRACE_ATTACH) {
765 ret = ptrace_attach(child);
767 * Some architectures need to do book-keeping after
768 * a ptrace attach.
770 if (!ret)
771 arch_ptrace_attach(child);
772 goto out_put_task_struct;
775 ret = ptrace_check_attach(child, request == PTRACE_KILL);
776 if (ret < 0)
777 goto out_put_task_struct;
779 ret = arch_ptrace(child, request, addr, data);
781 out_put_task_struct:
782 put_task_struct(child);
783 out:
784 return ret;
787 int generic_ptrace_peekdata(struct task_struct *tsk, unsigned long addr,
788 unsigned long data)
790 unsigned long tmp;
791 int copied;
793 copied = access_process_vm(tsk, addr, &tmp, sizeof(tmp), 0);
794 if (copied != sizeof(tmp))
795 return -EIO;
796 return put_user(tmp, (unsigned long __user *)data);
799 int generic_ptrace_pokedata(struct task_struct *tsk, unsigned long addr,
800 unsigned long data)
802 int copied;
804 copied = access_process_vm(tsk, addr, &data, sizeof(data), 1);
805 return (copied == sizeof(data)) ? 0 : -EIO;
808 #if defined CONFIG_COMPAT
809 #include <linux/compat.h>
811 int compat_ptrace_request(struct task_struct *child, compat_long_t request,
812 compat_ulong_t addr, compat_ulong_t data)
814 compat_ulong_t __user *datap = compat_ptr(data);
815 compat_ulong_t word;
816 siginfo_t siginfo;
817 int ret;
819 switch (request) {
820 case PTRACE_PEEKTEXT:
821 case PTRACE_PEEKDATA:
822 ret = access_process_vm(child, addr, &word, sizeof(word), 0);
823 if (ret != sizeof(word))
824 ret = -EIO;
825 else
826 ret = put_user(word, datap);
827 break;
829 case PTRACE_POKETEXT:
830 case PTRACE_POKEDATA:
831 ret = access_process_vm(child, addr, &data, sizeof(data), 1);
832 ret = (ret != sizeof(data) ? -EIO : 0);
833 break;
835 case PTRACE_GETEVENTMSG:
836 ret = put_user((compat_ulong_t) child->ptrace_message, datap);
837 break;
839 case PTRACE_GETSIGINFO:
840 ret = ptrace_getsiginfo(child, &siginfo);
841 if (!ret)
842 ret = copy_siginfo_to_user32(
843 (struct compat_siginfo __user *) datap,
844 &siginfo);
845 break;
847 case PTRACE_SETSIGINFO:
848 memset(&siginfo, 0, sizeof siginfo);
849 if (copy_siginfo_from_user32(
850 &siginfo, (struct compat_siginfo __user *) datap))
851 ret = -EFAULT;
852 else
853 ret = ptrace_setsiginfo(child, &siginfo);
854 break;
855 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
856 case PTRACE_GETREGSET:
857 case PTRACE_SETREGSET:
859 struct iovec kiov;
860 struct compat_iovec __user *uiov =
861 (struct compat_iovec __user *) datap;
862 compat_uptr_t ptr;
863 compat_size_t len;
865 if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov)))
866 return -EFAULT;
868 if (__get_user(ptr, &uiov->iov_base) ||
869 __get_user(len, &uiov->iov_len))
870 return -EFAULT;
872 kiov.iov_base = compat_ptr(ptr);
873 kiov.iov_len = len;
875 ret = ptrace_regset(child, request, addr, &kiov);
876 if (!ret)
877 ret = __put_user(kiov.iov_len, &uiov->iov_len);
878 break;
880 #endif
882 default:
883 ret = ptrace_request(child, request, addr, data);
886 return ret;
889 asmlinkage long compat_sys_ptrace(compat_long_t request, compat_long_t pid,
890 compat_long_t addr, compat_long_t data)
892 struct task_struct *child;
893 long ret;
895 if (request == PTRACE_TRACEME) {
896 ret = ptrace_traceme();
897 goto out;
900 child = ptrace_get_task_struct(pid);
901 if (IS_ERR(child)) {
902 ret = PTR_ERR(child);
903 goto out;
906 if (request == PTRACE_ATTACH) {
907 ret = ptrace_attach(child);
909 * Some architectures need to do book-keeping after
910 * a ptrace attach.
912 if (!ret)
913 arch_ptrace_attach(child);
914 goto out_put_task_struct;
917 ret = ptrace_check_attach(child, request == PTRACE_KILL);
918 if (!ret)
919 ret = compat_arch_ptrace(child, request, addr, data);
921 out_put_task_struct:
922 put_task_struct(child);
923 out:
924 return ret;
926 #endif /* CONFIG_COMPAT */
928 #ifdef CONFIG_HAVE_HW_BREAKPOINT
929 int ptrace_get_breakpoints(struct task_struct *tsk)
931 if (atomic_inc_not_zero(&tsk->ptrace_bp_refcnt))
932 return 0;
934 return -1;
937 void ptrace_put_breakpoints(struct task_struct *tsk)
939 if (atomic_dec_and_test(&tsk->ptrace_bp_refcnt))
940 flush_ptrace_hw_breakpoint(tsk);
942 #endif /* CONFIG_HAVE_HW_BREAKPOINT */