[PATCH] epoll_pwait()

[net-next-2.6.git] / fs / eventpoll.c

diff --git a/fs/eventpoll.c b/fs/eventpoll.c
index 557d5b614fae6ba694703b86d950471cc2eeedc5..ae228ec54e948a63b25bb39f34577baa22fd06ed 100644 (file)
--- a/fs/eventpoll.c
+++ b/fs/eventpoll.c
@@ -105,6 +105,8 @@
 /* Maximum msec timeout value storeable in a long int */
 #define EP_MAX_MSTIMEO min(1000ULL * MAX_SCHEDULE_TIMEOUT / HZ, (LONG_MAX - 999ULL) / HZ)
 
+#define EP_MAX_EVENTS (INT_MAX / sizeof(struct epoll_event))
+
 
 struct epoll_filefd {
        struct file *file;
@@ -497,7 +499,7 @@ void eventpoll_release_file(struct file *file)
  */
 asmlinkage long sys_epoll_create(int size)
 {
-       int error, fd;
+       int error, fd = -1;
        struct eventpoll *ep;
        struct inode *inode;
        struct file *file;
@@ -640,7 +642,6 @@ eexit_1:
        return error;
 }
 
-#define MAX_EVENTS (INT_MAX / sizeof(struct epoll_event))
 
 /*
  * Implement the event wait interface for the eventpoll file. It is the kernel
@@ -657,7 +658,7 @@ asmlinkage long sys_epoll_wait(int epfd, struct epoll_event __user *events,
                     current, epfd, events, maxevents, timeout));
 
        /* The maximum number of event must be greater than zero */
-       if (maxevents <= 0 || maxevents > MAX_EVENTS)
+       if (maxevents <= 0 || maxevents > EP_MAX_EVENTS)
                return -EINVAL;
 
        /* Verify that the area passed by the user is writeable */
@@ -699,6 +700,55 @@ eexit_1:
 }
 
 
+#ifdef TIF_RESTORE_SIGMASK
+
+/*
+ * Implement the event wait interface for the eventpoll file. It is the kernel
+ * part of the user space epoll_pwait(2).
+ */
+asmlinkage long sys_epoll_pwait(int epfd, struct epoll_event __user *events,
+               int maxevents, int timeout, const sigset_t __user *sigmask,
+               size_t sigsetsize)
+{
+       int error;
+       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(sigset_t))
+                       return -EINVAL;
+               if (copy_from_user(&ksigmask, sigmask, sizeof(ksigmask)))
+                       return -EFAULT;
+               sigdelsetmask(&ksigmask, sigmask(SIGKILL) | sigmask(SIGSTOP));
+               sigprocmask(SIG_SETMASK, &ksigmask, &sigsaved);
+       }
+
+       error = 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 (error == -EINTR) {
+                       memcpy(&current->saved_sigmask, &sigsaved,
+                               sizeof(sigsaved));
+                       set_thread_flag(TIF_RESTORE_SIGMASK);
+               } else
+                       sigprocmask(SIG_SETMASK, &sigsaved, NULL);
+       }
+
+       return error;
+}
+
+#endif /* #ifdef TIF_RESTORE_SIGMASK */
+
+
 /*
  * Creates the file descriptor to be used by the epoll interface.
  */