Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal

[pandora-kernel.git] / fs / eventpoll.c

diff --git a/fs/eventpoll.c b/fs/eventpoll.c
index 277cc38..deecc72 100644 (file)
--- a/fs/eventpoll.c
+++ b/fs/eventpoll.c
@@ -40,6 +40,7 @@
 #include <linux/atomic.h>
 #include <linux/proc_fs.h>
 #include <linux/seq_file.h>
+#include <linux/compat.h>
 
 /*
  * LOCKING:
@@ -1998,6 +1999,52 @@ SYSCALL_DEFINE6(epoll_pwait, int, epfd, struct epoll_event __user *, events,
        return error;
 }
 
+#ifdef CONFIG_COMPAT
+COMPAT_SYSCALL_DEFINE6(epoll_pwait, int, epfd,
+                       struct epoll_event __user *, events,
+                       int, maxevents, int, timeout,
+                       const compat_sigset_t __user *, sigmask,
+                       compat_size_t, sigsetsize)
+{
+       long err;
+       compat_sigset_t csigmask;
+       sigset_t ksigmask, sigsaved;
+
+       /*
+        * If the caller wants a certain signal mask to be set during the wait,
+        * we apply it here.
+        */
+       if (sigmask) {
+               if (sigsetsize != sizeof(compat_sigset_t))
+                       return -EINVAL;
+               if (copy_from_user(&csigmask, sigmask, sizeof(csigmask)))
+                       return -EFAULT;
+               sigset_from_compat(&ksigmask, &csigmask);
+               sigdelsetmask(&ksigmask, sigmask(SIGKILL) | sigmask(SIGSTOP));
+               sigprocmask(SIG_SETMASK, &ksigmask, &sigsaved);
+       }
+
+       err = sys_epoll_wait(epfd, events, maxevents, timeout);
+
+       /*
+        * If we changed the signal mask, we need to restore the original one.
+        * In case we've got a signal while waiting, we do not restore the
+        * signal mask yet, and we allow do_signal() to deliver the signal on
+        * the way back to userspace, before the signal mask is restored.
+        */
+       if (sigmask) {
+               if (err == -EINTR) {
+                       memcpy(&current->saved_sigmask, &sigsaved,
+                              sizeof(sigsaved));
+                       set_restore_sigmask();
+               } else
+                       sigprocmask(SIG_SETMASK, &sigsaved, NULL);
+       }
+
+       return err;
+}
+#endif
+
 static int __init eventpoll_init(void)
 {
        struct sysinfo si;