Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris...
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / kernel / ptrace.c
blob0fc1eed28d2783e0b2779fe50d1ff86fbf4ca858
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>
28 * ptrace a task: make the debugger its new parent and
29 * move it to the ptrace list.
31 * Must be called with the tasklist lock write-held.
33 void __ptrace_link(struct task_struct *child, struct task_struct *new_parent)
35 BUG_ON(!list_empty(&child->ptrace_entry));
36 list_add(&child->ptrace_entry, &new_parent->ptraced);
37 child->parent = new_parent;
41 * Turn a tracing stop into a normal stop now, since with no tracer there
42 * would be no way to wake it up with SIGCONT or SIGKILL. If there was a
43 * signal sent that would resume the child, but didn't because it was in
44 * TASK_TRACED, resume it now.
45 * Requires that irqs be disabled.
47 static void ptrace_untrace(struct task_struct *child)
49 spin_lock(&child->sighand->siglock);
50 if (task_is_traced(child)) {
52 * If the group stop is completed or in progress,
53 * this thread was already counted as stopped.
55 if (child->signal->flags & SIGNAL_STOP_STOPPED ||
56 child->signal->group_stop_count)
57 __set_task_state(child, TASK_STOPPED);
58 else
59 signal_wake_up(child, 1);
61 spin_unlock(&child->sighand->siglock);
65 * unptrace a task: move it back to its original parent and
66 * remove it from the ptrace list.
68 * Must be called with the tasklist lock write-held.
70 void __ptrace_unlink(struct task_struct *child)
72 BUG_ON(!child->ptrace);
74 child->ptrace = 0;
75 child->parent = child->real_parent;
76 list_del_init(&child->ptrace_entry);
78 if (task_is_traced(child))
79 ptrace_untrace(child);
83 * Check that we have indeed attached to the thing..
85 int ptrace_check_attach(struct task_struct *child, int kill)
87 int ret = -ESRCH;
90 * We take the read lock around doing both checks to close a
91 * possible race where someone else was tracing our child and
92 * detached between these two checks. After this locked check,
93 * we are sure that this is our traced child and that can only
94 * be changed by us so it's not changing right after this.
96 read_lock(&tasklist_lock);
97 if ((child->ptrace & PT_PTRACED) && child->parent == current) {
98 ret = 0;
100 * child->sighand can't be NULL, release_task()
101 * does ptrace_unlink() before __exit_signal().
103 spin_lock_irq(&child->sighand->siglock);
104 if (task_is_stopped(child))
105 child->state = TASK_TRACED;
106 else if (!task_is_traced(child) && !kill)
107 ret = -ESRCH;
108 spin_unlock_irq(&child->sighand->siglock);
110 read_unlock(&tasklist_lock);
112 if (!ret && !kill)
113 ret = wait_task_inactive(child, TASK_TRACED) ? 0 : -ESRCH;
115 /* All systems go.. */
116 return ret;
119 int __ptrace_may_access(struct task_struct *task, unsigned int mode)
121 const struct cred *cred = current_cred(), *tcred;
123 /* May we inspect the given task?
124 * This check is used both for attaching with ptrace
125 * and for allowing access to sensitive information in /proc.
127 * ptrace_attach denies several cases that /proc allows
128 * because setting up the necessary parent/child relationship
129 * or halting the specified task is impossible.
131 int dumpable = 0;
132 /* Don't let security modules deny introspection */
133 if (task == current)
134 return 0;
135 rcu_read_lock();
136 tcred = __task_cred(task);
137 if (cred->user->user_ns == tcred->user->user_ns &&
138 (cred->uid == tcred->euid &&
139 cred->uid == tcred->suid &&
140 cred->uid == tcred->uid &&
141 cred->gid == tcred->egid &&
142 cred->gid == tcred->sgid &&
143 cred->gid == tcred->gid))
144 goto ok;
145 if (ns_capable(tcred->user->user_ns, CAP_SYS_PTRACE))
146 goto ok;
147 rcu_read_unlock();
148 return -EPERM;
150 rcu_read_unlock();
151 smp_rmb();
152 if (task->mm)
153 dumpable = get_dumpable(task->mm);
154 if (!dumpable && !task_ns_capable(task, CAP_SYS_PTRACE))
155 return -EPERM;
157 return security_ptrace_access_check(task, mode);
160 bool ptrace_may_access(struct task_struct *task, unsigned int mode)
162 int err;
163 task_lock(task);
164 err = __ptrace_may_access(task, mode);
165 task_unlock(task);
166 return !err;
169 static int ptrace_attach(struct task_struct *task)
171 int retval;
173 audit_ptrace(task);
175 retval = -EPERM;
176 if (unlikely(task->flags & PF_KTHREAD))
177 goto out;
178 if (same_thread_group(task, current))
179 goto out;
182 * Protect exec's credential calculations against our interference;
183 * interference; SUID, SGID and LSM creds get determined differently
184 * under ptrace.
186 retval = -ERESTARTNOINTR;
187 if (mutex_lock_interruptible(&task->signal->cred_guard_mutex))
188 goto out;
190 task_lock(task);
191 retval = __ptrace_may_access(task, PTRACE_MODE_ATTACH);
192 task_unlock(task);
193 if (retval)
194 goto unlock_creds;
196 write_lock_irq(&tasklist_lock);
197 retval = -EPERM;
198 if (unlikely(task->exit_state))
199 goto unlock_tasklist;
200 if (task->ptrace)
201 goto unlock_tasklist;
203 task->ptrace = PT_PTRACED;
204 if (task_ns_capable(task, CAP_SYS_PTRACE))
205 task->ptrace |= PT_PTRACE_CAP;
207 __ptrace_link(task, current);
208 send_sig_info(SIGSTOP, SEND_SIG_FORCED, task);
210 retval = 0;
211 unlock_tasklist:
212 write_unlock_irq(&tasklist_lock);
213 unlock_creds:
214 mutex_unlock(&task->signal->cred_guard_mutex);
215 out:
216 return retval;
220 * ptrace_traceme -- helper for PTRACE_TRACEME
222 * Performs checks and sets PT_PTRACED.
223 * Should be used by all ptrace implementations for PTRACE_TRACEME.
225 static int ptrace_traceme(void)
227 int ret = -EPERM;
229 write_lock_irq(&tasklist_lock);
230 /* Are we already being traced? */
231 if (!current->ptrace) {
232 ret = security_ptrace_traceme(current->parent);
234 * Check PF_EXITING to ensure ->real_parent has not passed
235 * exit_ptrace(). Otherwise we don't report the error but
236 * pretend ->real_parent untraces us right after return.
238 if (!ret && !(current->real_parent->flags & PF_EXITING)) {
239 current->ptrace = PT_PTRACED;
240 __ptrace_link(current, current->real_parent);
243 write_unlock_irq(&tasklist_lock);
245 return ret;
249 * Called with irqs disabled, returns true if childs should reap themselves.
251 static int ignoring_children(struct sighand_struct *sigh)
253 int ret;
254 spin_lock(&sigh->siglock);
255 ret = (sigh->action[SIGCHLD-1].sa.sa_handler == SIG_IGN) ||
256 (sigh->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT);
257 spin_unlock(&sigh->siglock);
258 return ret;
262 * Called with tasklist_lock held for writing.
263 * Unlink a traced task, and clean it up if it was a traced zombie.
264 * Return true if it needs to be reaped with release_task().
265 * (We can't call release_task() here because we already hold tasklist_lock.)
267 * If it's a zombie, our attachedness prevented normal parent notification
268 * or self-reaping. Do notification now if it would have happened earlier.
269 * If it should reap itself, return true.
271 * If it's our own child, there is no notification to do. But if our normal
272 * children self-reap, then this child was prevented by ptrace and we must
273 * reap it now, in that case we must also wake up sub-threads sleeping in
274 * do_wait().
276 static bool __ptrace_detach(struct task_struct *tracer, struct task_struct *p)
278 __ptrace_unlink(p);
280 if (p->exit_state == EXIT_ZOMBIE) {
281 if (!task_detached(p) && thread_group_empty(p)) {
282 if (!same_thread_group(p->real_parent, tracer))
283 do_notify_parent(p, p->exit_signal);
284 else if (ignoring_children(tracer->sighand)) {
285 __wake_up_parent(p, tracer);
286 p->exit_signal = -1;
289 if (task_detached(p)) {
290 /* Mark it as in the process of being reaped. */
291 p->exit_state = EXIT_DEAD;
292 return true;
296 return false;
299 static int ptrace_detach(struct task_struct *child, unsigned int data)
301 bool dead = false;
303 if (!valid_signal(data))
304 return -EIO;
306 /* Architecture-specific hardware disable .. */
307 ptrace_disable(child);
308 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
310 write_lock_irq(&tasklist_lock);
312 * This child can be already killed. Make sure de_thread() or
313 * our sub-thread doing do_wait() didn't do release_task() yet.
315 if (child->ptrace) {
316 child->exit_code = data;
317 dead = __ptrace_detach(current, child);
318 if (!child->exit_state)
319 wake_up_state(child, TASK_TRACED | TASK_STOPPED);
321 write_unlock_irq(&tasklist_lock);
323 if (unlikely(dead))
324 release_task(child);
326 return 0;
330 * Detach all tasks we were using ptrace on. Called with tasklist held
331 * for writing, and returns with it held too. But note it can release
332 * and reacquire the lock.
334 void exit_ptrace(struct task_struct *tracer)
335 __releases(&tasklist_lock)
336 __acquires(&tasklist_lock)
338 struct task_struct *p, *n;
339 LIST_HEAD(ptrace_dead);
341 if (likely(list_empty(&tracer->ptraced)))
342 return;
344 list_for_each_entry_safe(p, n, &tracer->ptraced, ptrace_entry) {
345 if (__ptrace_detach(tracer, p))
346 list_add(&p->ptrace_entry, &ptrace_dead);
349 write_unlock_irq(&tasklist_lock);
350 BUG_ON(!list_empty(&tracer->ptraced));
352 list_for_each_entry_safe(p, n, &ptrace_dead, ptrace_entry) {
353 list_del_init(&p->ptrace_entry);
354 release_task(p);
357 write_lock_irq(&tasklist_lock);
360 int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len)
362 int copied = 0;
364 while (len > 0) {
365 char buf[128];
366 int this_len, retval;
368 this_len = (len > sizeof(buf)) ? sizeof(buf) : len;
369 retval = access_process_vm(tsk, src, buf, this_len, 0);
370 if (!retval) {
371 if (copied)
372 break;
373 return -EIO;
375 if (copy_to_user(dst, buf, retval))
376 return -EFAULT;
377 copied += retval;
378 src += retval;
379 dst += retval;
380 len -= retval;
382 return copied;
385 int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len)
387 int copied = 0;
389 while (len > 0) {
390 char buf[128];
391 int this_len, retval;
393 this_len = (len > sizeof(buf)) ? sizeof(buf) : len;
394 if (copy_from_user(buf, src, this_len))
395 return -EFAULT;
396 retval = access_process_vm(tsk, dst, buf, this_len, 1);
397 if (!retval) {
398 if (copied)
399 break;
400 return -EIO;
402 copied += retval;
403 src += retval;
404 dst += retval;
405 len -= retval;
407 return copied;
410 static int ptrace_setoptions(struct task_struct *child, unsigned long data)
412 child->ptrace &= ~PT_TRACE_MASK;
414 if (data & PTRACE_O_TRACESYSGOOD)
415 child->ptrace |= PT_TRACESYSGOOD;
417 if (data & PTRACE_O_TRACEFORK)
418 child->ptrace |= PT_TRACE_FORK;
420 if (data & PTRACE_O_TRACEVFORK)
421 child->ptrace |= PT_TRACE_VFORK;
423 if (data & PTRACE_O_TRACECLONE)
424 child->ptrace |= PT_TRACE_CLONE;
426 if (data & PTRACE_O_TRACEEXEC)
427 child->ptrace |= PT_TRACE_EXEC;
429 if (data & PTRACE_O_TRACEVFORKDONE)
430 child->ptrace |= PT_TRACE_VFORK_DONE;
432 if (data & PTRACE_O_TRACEEXIT)
433 child->ptrace |= PT_TRACE_EXIT;
435 return (data & ~PTRACE_O_MASK) ? -EINVAL : 0;
438 static int ptrace_getsiginfo(struct task_struct *child, siginfo_t *info)
440 unsigned long flags;
441 int error = -ESRCH;
443 if (lock_task_sighand(child, &flags)) {
444 error = -EINVAL;
445 if (likely(child->last_siginfo != NULL)) {
446 *info = *child->last_siginfo;
447 error = 0;
449 unlock_task_sighand(child, &flags);
451 return error;
454 static int ptrace_setsiginfo(struct task_struct *child, const siginfo_t *info)
456 unsigned long flags;
457 int error = -ESRCH;
459 if (lock_task_sighand(child, &flags)) {
460 error = -EINVAL;
461 if (likely(child->last_siginfo != NULL)) {
462 *child->last_siginfo = *info;
463 error = 0;
465 unlock_task_sighand(child, &flags);
467 return error;
471 #ifdef PTRACE_SINGLESTEP
472 #define is_singlestep(request) ((request) == PTRACE_SINGLESTEP)
473 #else
474 #define is_singlestep(request) 0
475 #endif
477 #ifdef PTRACE_SINGLEBLOCK
478 #define is_singleblock(request) ((request) == PTRACE_SINGLEBLOCK)
479 #else
480 #define is_singleblock(request) 0
481 #endif
483 #ifdef PTRACE_SYSEMU
484 #define is_sysemu_singlestep(request) ((request) == PTRACE_SYSEMU_SINGLESTEP)
485 #else
486 #define is_sysemu_singlestep(request) 0
487 #endif
489 static int ptrace_resume(struct task_struct *child, long request,
490 unsigned long data)
492 if (!valid_signal(data))
493 return -EIO;
495 if (request == PTRACE_SYSCALL)
496 set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
497 else
498 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
500 #ifdef TIF_SYSCALL_EMU
501 if (request == PTRACE_SYSEMU || request == PTRACE_SYSEMU_SINGLESTEP)
502 set_tsk_thread_flag(child, TIF_SYSCALL_EMU);
503 else
504 clear_tsk_thread_flag(child, TIF_SYSCALL_EMU);
505 #endif
507 if (is_singleblock(request)) {
508 if (unlikely(!arch_has_block_step()))
509 return -EIO;
510 user_enable_block_step(child);
511 } else if (is_singlestep(request) || is_sysemu_singlestep(request)) {
512 if (unlikely(!arch_has_single_step()))
513 return -EIO;
514 user_enable_single_step(child);
515 } else {
516 user_disable_single_step(child);
519 child->exit_code = data;
520 wake_up_process(child);
522 return 0;
525 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
527 static const struct user_regset *
528 find_regset(const struct user_regset_view *view, unsigned int type)
530 const struct user_regset *regset;
531 int n;
533 for (n = 0; n < view->n; ++n) {
534 regset = view->regsets + n;
535 if (regset->core_note_type == type)
536 return regset;
539 return NULL;
542 static int ptrace_regset(struct task_struct *task, int req, unsigned int type,
543 struct iovec *kiov)
545 const struct user_regset_view *view = task_user_regset_view(task);
546 const struct user_regset *regset = find_regset(view, type);
547 int regset_no;
549 if (!regset || (kiov->iov_len % regset->size) != 0)
550 return -EINVAL;
552 regset_no = regset - view->regsets;
553 kiov->iov_len = min(kiov->iov_len,
554 (__kernel_size_t) (regset->n * regset->size));
556 if (req == PTRACE_GETREGSET)
557 return copy_regset_to_user(task, view, regset_no, 0,
558 kiov->iov_len, kiov->iov_base);
559 else
560 return copy_regset_from_user(task, view, regset_no, 0,
561 kiov->iov_len, kiov->iov_base);
564 #endif
566 int ptrace_request(struct task_struct *child, long request,
567 unsigned long addr, unsigned long data)
569 int ret = -EIO;
570 siginfo_t siginfo;
571 void __user *datavp = (void __user *) data;
572 unsigned long __user *datalp = datavp;
574 switch (request) {
575 case PTRACE_PEEKTEXT:
576 case PTRACE_PEEKDATA:
577 return generic_ptrace_peekdata(child, addr, data);
578 case PTRACE_POKETEXT:
579 case PTRACE_POKEDATA:
580 return generic_ptrace_pokedata(child, addr, data);
582 #ifdef PTRACE_OLDSETOPTIONS
583 case PTRACE_OLDSETOPTIONS:
584 #endif
585 case PTRACE_SETOPTIONS:
586 ret = ptrace_setoptions(child, data);
587 break;
588 case PTRACE_GETEVENTMSG:
589 ret = put_user(child->ptrace_message, datalp);
590 break;
592 case PTRACE_GETSIGINFO:
593 ret = ptrace_getsiginfo(child, &siginfo);
594 if (!ret)
595 ret = copy_siginfo_to_user(datavp, &siginfo);
596 break;
598 case PTRACE_SETSIGINFO:
599 if (copy_from_user(&siginfo, datavp, sizeof siginfo))
600 ret = -EFAULT;
601 else
602 ret = ptrace_setsiginfo(child, &siginfo);
603 break;
605 case PTRACE_DETACH: /* detach a process that was attached. */
606 ret = ptrace_detach(child, data);
607 break;
609 #ifdef CONFIG_BINFMT_ELF_FDPIC
610 case PTRACE_GETFDPIC: {
611 struct mm_struct *mm = get_task_mm(child);
612 unsigned long tmp = 0;
614 ret = -ESRCH;
615 if (!mm)
616 break;
618 switch (addr) {
619 case PTRACE_GETFDPIC_EXEC:
620 tmp = mm->context.exec_fdpic_loadmap;
621 break;
622 case PTRACE_GETFDPIC_INTERP:
623 tmp = mm->context.interp_fdpic_loadmap;
624 break;
625 default:
626 break;
628 mmput(mm);
630 ret = put_user(tmp, datalp);
631 break;
633 #endif
635 #ifdef PTRACE_SINGLESTEP
636 case PTRACE_SINGLESTEP:
637 #endif
638 #ifdef PTRACE_SINGLEBLOCK
639 case PTRACE_SINGLEBLOCK:
640 #endif
641 #ifdef PTRACE_SYSEMU
642 case PTRACE_SYSEMU:
643 case PTRACE_SYSEMU_SINGLESTEP:
644 #endif
645 case PTRACE_SYSCALL:
646 case PTRACE_CONT:
647 return ptrace_resume(child, request, data);
649 case PTRACE_KILL:
650 if (child->exit_state) /* already dead */
651 return 0;
652 return ptrace_resume(child, request, SIGKILL);
654 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
655 case PTRACE_GETREGSET:
656 case PTRACE_SETREGSET:
658 struct iovec kiov;
659 struct iovec __user *uiov = datavp;
661 if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov)))
662 return -EFAULT;
664 if (__get_user(kiov.iov_base, &uiov->iov_base) ||
665 __get_user(kiov.iov_len, &uiov->iov_len))
666 return -EFAULT;
668 ret = ptrace_regset(child, request, addr, &kiov);
669 if (!ret)
670 ret = __put_user(kiov.iov_len, &uiov->iov_len);
671 break;
673 #endif
674 default:
675 break;
678 return ret;
681 static struct task_struct *ptrace_get_task_struct(pid_t pid)
683 struct task_struct *child;
685 rcu_read_lock();
686 child = find_task_by_vpid(pid);
687 if (child)
688 get_task_struct(child);
689 rcu_read_unlock();
691 if (!child)
692 return ERR_PTR(-ESRCH);
693 return child;
696 #ifndef arch_ptrace_attach
697 #define arch_ptrace_attach(child) do { } while (0)
698 #endif
700 SYSCALL_DEFINE4(ptrace, long, request, long, pid, unsigned long, addr,
701 unsigned long, data)
703 struct task_struct *child;
704 long ret;
706 if (request == PTRACE_TRACEME) {
707 ret = ptrace_traceme();
708 if (!ret)
709 arch_ptrace_attach(current);
710 goto out;
713 child = ptrace_get_task_struct(pid);
714 if (IS_ERR(child)) {
715 ret = PTR_ERR(child);
716 goto out;
719 if (request == PTRACE_ATTACH) {
720 ret = ptrace_attach(child);
722 * Some architectures need to do book-keeping after
723 * a ptrace attach.
725 if (!ret)
726 arch_ptrace_attach(child);
727 goto out_put_task_struct;
730 ret = ptrace_check_attach(child, request == PTRACE_KILL);
731 if (ret < 0)
732 goto out_put_task_struct;
734 ret = arch_ptrace(child, request, addr, data);
736 out_put_task_struct:
737 put_task_struct(child);
738 out:
739 return ret;
742 int generic_ptrace_peekdata(struct task_struct *tsk, unsigned long addr,
743 unsigned long data)
745 unsigned long tmp;
746 int copied;
748 copied = access_process_vm(tsk, addr, &tmp, sizeof(tmp), 0);
749 if (copied != sizeof(tmp))
750 return -EIO;
751 return put_user(tmp, (unsigned long __user *)data);
754 int generic_ptrace_pokedata(struct task_struct *tsk, unsigned long addr,
755 unsigned long data)
757 int copied;
759 copied = access_process_vm(tsk, addr, &data, sizeof(data), 1);
760 return (copied == sizeof(data)) ? 0 : -EIO;
763 #if defined CONFIG_COMPAT
764 #include <linux/compat.h>
766 int compat_ptrace_request(struct task_struct *child, compat_long_t request,
767 compat_ulong_t addr, compat_ulong_t data)
769 compat_ulong_t __user *datap = compat_ptr(data);
770 compat_ulong_t word;
771 siginfo_t siginfo;
772 int ret;
774 switch (request) {
775 case PTRACE_PEEKTEXT:
776 case PTRACE_PEEKDATA:
777 ret = access_process_vm(child, addr, &word, sizeof(word), 0);
778 if (ret != sizeof(word))
779 ret = -EIO;
780 else
781 ret = put_user(word, datap);
782 break;
784 case PTRACE_POKETEXT:
785 case PTRACE_POKEDATA:
786 ret = access_process_vm(child, addr, &data, sizeof(data), 1);
787 ret = (ret != sizeof(data) ? -EIO : 0);
788 break;
790 case PTRACE_GETEVENTMSG:
791 ret = put_user((compat_ulong_t) child->ptrace_message, datap);
792 break;
794 case PTRACE_GETSIGINFO:
795 ret = ptrace_getsiginfo(child, &siginfo);
796 if (!ret)
797 ret = copy_siginfo_to_user32(
798 (struct compat_siginfo __user *) datap,
799 &siginfo);
800 break;
802 case PTRACE_SETSIGINFO:
803 memset(&siginfo, 0, sizeof siginfo);
804 if (copy_siginfo_from_user32(
805 &siginfo, (struct compat_siginfo __user *) datap))
806 ret = -EFAULT;
807 else
808 ret = ptrace_setsiginfo(child, &siginfo);
809 break;
810 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
811 case PTRACE_GETREGSET:
812 case PTRACE_SETREGSET:
814 struct iovec kiov;
815 struct compat_iovec __user *uiov =
816 (struct compat_iovec __user *) datap;
817 compat_uptr_t ptr;
818 compat_size_t len;
820 if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov)))
821 return -EFAULT;
823 if (__get_user(ptr, &uiov->iov_base) ||
824 __get_user(len, &uiov->iov_len))
825 return -EFAULT;
827 kiov.iov_base = compat_ptr(ptr);
828 kiov.iov_len = len;
830 ret = ptrace_regset(child, request, addr, &kiov);
831 if (!ret)
832 ret = __put_user(kiov.iov_len, &uiov->iov_len);
833 break;
835 #endif
837 default:
838 ret = ptrace_request(child, request, addr, data);
841 return ret;
844 asmlinkage long compat_sys_ptrace(compat_long_t request, compat_long_t pid,
845 compat_long_t addr, compat_long_t data)
847 struct task_struct *child;
848 long ret;
850 if (request == PTRACE_TRACEME) {
851 ret = ptrace_traceme();
852 goto out;
855 child = ptrace_get_task_struct(pid);
856 if (IS_ERR(child)) {
857 ret = PTR_ERR(child);
858 goto out;
861 if (request == PTRACE_ATTACH) {
862 ret = ptrace_attach(child);
864 * Some architectures need to do book-keeping after
865 * a ptrace attach.
867 if (!ret)
868 arch_ptrace_attach(child);
869 goto out_put_task_struct;
872 ret = ptrace_check_attach(child, request == PTRACE_KILL);
873 if (!ret)
874 ret = compat_arch_ptrace(child, request, addr, data);
876 out_put_task_struct:
877 put_task_struct(child);
878 out:
879 return ret;
881 #endif /* CONFIG_COMPAT */