uClibc: fix uClibc implementation of eventfd

uClibc declares eventfd() as taking two arguments but doesn't properly
pass the second argument to the kernel.

The problem is discussed at:
http://lists.uclibc.org/pipermail/uclibc/2012-May/046873.html



This patch is taken from uclibc 0.9.33 git, so will presumably
be integrated in any future releases.

Signed-off-by: Andy Leiserson <andy@leiserson.org>

SVN-Revision: 33478

toolchain/uClibc/patches-0.9.33.2/500-eventfd.patch

+From 7810e4f8027b5c4c8ceec6fefec4eb779362ebb5 Mon Sep 17 00:00:00 2001
+From: Khem Raj <raj.khem@gmail.com>
+Date: Sun, 10 Jun 2012 16:36:23 +0000
+Subject: eventfd: Implement eventfd2 and fix eventfd
+
+eventfd: evntfd assumes to take two arguments instead it
+should be one evntfd expects two therefore implement both syscalls with
+correct parameters
+
+Thanks Eugene Rudoy for reporting it and also providing the patch
+
+Signed-off-by: Khem Raj <raj.khem@gmail.com>
+---
+diff --git a/libc/sysdeps/linux/common/eventfd.c b/libc/sysdeps/linux/common/eventfd.c
+index cc3f3f0..96597ab 100644
+--- a/libc/sysdeps/linux/common/eventfd.c
++++ b/libc/sysdeps/linux/common/eventfd.c
+@@ -7,12 +7,24 @@
+  * Licensed under the LGPL v2.1, see the file COPYING.LIB in this tarball.
+  */
+ 
++#include <errno.h>
+ #include <sys/syscall.h>
+ #include <sys/eventfd.h>
+ 
+ /*
+  * eventfd()
+  */
+-#ifdef __NR_eventfd
+-_syscall2(int, eventfd, int, count, int, flags)
++#if defined __NR_eventfd || defined __NR_eventfd2
++int eventfd (int count, int flags)
++{
++#if defined __NR_eventfd2
++  return INLINE_SYSCALL (eventfd2, 2, count, flags);
++#elif defined __NR_eventfd
++  if (flags != 0) {
++     __set_errno (EINVAL);
++    return -1;
++  }
++  return INLINE_SYSCALL (eventfd, 1, count);
++#endif
++}
+ #endif
+diff --git a/libc/sysdeps/linux/common/stubs.c b/libc/sysdeps/linux/common/stubs.c
+index 4d1e26c..7af14c1 100644
+--- a/libc/sysdeps/linux/common/stubs.c
++++ b/libc/sysdeps/linux/common/stubs.c
+@@ -93,7 +93,7 @@ make_stub(epoll_ctl)
+ make_stub(epoll_wait)
+ #endif
+ 
+-#if !defined __NR_eventfd && defined __UCLIBC_LINUX_SPECIFIC__
++#if !defined __NR_eventfd && !defined __NR_eventfd2 && defined __UCLIBC_LINUX_SPECIFIC__
+ make_stub(eventfd)
+ #endif
+ 
+--
+cgit v0.9.0.1-2-gef13