[PATCH] Fix epoll_pwait (BZ #4525)

[Jakub Jelinek <jakub at redhat dot com>]

Hi!

epoll_pwait syscall takes 6 arguments (last should be _NSIG / 8
(!= sizeof (sigset_t))), while glibc prototype only provides 5 arguments.
I'd say it should behave like sigsuspend in this regard.

Another issue is that x86_64 has its own sys/epoll.h header, the patch
below mirrors the 2006-10-11 changes from Linux sys/epoll.h there.

2007-05-21  Jakub Jelinek  <jakub@redhat.com>

	[BZ #4525]
	* sysdeps/unix/sysv/linux/Makefile (sysdep_routines): Add epoll_pwait.
	* sysdeps/unix/sysv/linux/epoll_pwait.c: New file.
	* sysdeps/unix/sysv/linux/syscalls.list (epoll_pwait): Remove.

	* sysdeps/unix/sysv/linux/x86_64/sys/epoll.h (epoll_pwait): Declare.

--- libc/sysdeps/unix/sysv/linux/Makefile.jj	2007-05-04 11:38:30.000000000 +0200
+++ libc/sysdeps/unix/sysv/linux/Makefile	2007-05-21 12:22:01.000000000 +0200
@@ -13,7 +13,7 @@ endif
 
 ifeq ($(subdir),misc)
 sysdep_routines += sysctl clone llseek umount umount2 readahead \
-		   setfsuid setfsgid makedev
+		   setfsuid setfsgid makedev epoll_pwait
 
 CFLAGS-gethostid.c = -fexceptions
 
--- libc/sysdeps/unix/sysv/linux/epoll_pwait.c.jj	2007-05-21 12:16:27.000000000 +0200
+++ libc/sysdeps/unix/sysv/linux/epoll_pwait.c	2007-05-21 12:43:13.000000000 +0200
@@ -0,0 +1,69 @@
+/* Copyright (C) 2007 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#include <errno.h>
+#include <signal.h>
+#include <unistd.h>
+#include <sys/epoll.h>
+
+#include <sysdep-cancel.h>
+#include <sys/syscall.h>
+
+#ifdef __NR_epoll_pwait
+
+/* Wait for events on an epoll instance "epfd". Returns the number of
+   triggered events returned in "events" buffer. Or -1 in case of
+   error with the "errno" variable set to the specific error code. The
+   "events" parameter is a buffer that will contain triggered
+   events. The "maxevents" is the maximum number of events to be
+   returned ( usually size of "events" ). The "timeout" parameter
+   specifies the maximum wait time in milliseconds (-1 == infinite).
+   The thread's signal mask is temporarily and atomically replaced with
+   the one provided as parameter.  */
+
+int epoll_pwait (int epfd, struct epoll_event *events,
+		 int maxevents, int timeout,
+		 const sigset_t *set)
+{
+  if (SINGLE_THREAD_P)
+    return INLINE_SYSCALL (epoll_pwait, 6, epfd, events, maxevents, timeout,
+			   set, _NSIG / 8);
+
+  int oldtype = LIBC_CANCEL_ASYNC ();
+
+  int result = INLINE_SYSCALL (epoll_pwait, 6, epfd, events, maxevents,
+			       timeout, set, _NSIG / 8);
+
+  LIBC_CANCEL_RESET (oldtype);
+
+  return result;
+}
+
+#else
+
+int epoll_pwait (int epfd, struct epoll_event *events,
+		 int maxevents, int timeout,
+		 const sigset_t *set)
+{
+  __set_errno (ENOSYS);
+  return -1;
+}
+stub_warning (epoll_pwait)
+
+# include <stub-tag.h>
+#endif
--- libc/sysdeps/unix/sysv/linux/syscalls.list.jj	2007-05-09 13:26:17.000000000 +0200
+++ libc/sysdeps/unix/sysv/linux/syscalls.list	2007-05-21 12:16:13.000000000 +0200
@@ -10,7 +10,6 @@ delete_module	EXTRA	delete_module	3	dele
 epoll_create	EXTRA	epoll_create	i:i	epoll_create
 epoll_ctl	EXTRA	epoll_ctl	i:iiip	epoll_ctl
 epoll_wait	EXTRA	epoll_wait	Ci:ipii	epoll_wait
-epoll_pwait	EXTRA	epoll_pwait	Ci:ipiipi	epoll_pwait
 fdatasync	-	fdatasync	Ci:i	fdatasync
 flock		-	flock		i:ii	__flock		flock
 fork		-	fork		i:	__libc_fork	__fork fork
--- libc/sysdeps/unix/sysv/linux/x86_64/sys/epoll.h.jj	2006-02-22 06:48:50.000000000 +0100
+++ libc/sysdeps/unix/sysv/linux/x86_64/sys/epoll.h	2007-05-21 12:15:22.000000000 +0200
@@ -1,4 +1,4 @@
-/* Copyright (C) 2002,2003,2004,2005,2006 Free Software Foundation, Inc.
+/* Copyright (C) 2002,2003,2004,2005,2006,2007 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
 
    The GNU C Library is free software; you can redistribute it and/or
@@ -22,6 +22,14 @@
 #include <stdint.h>
 #include <sys/types.h>
 
+/* Get __sigset_t.  */
+#include <bits/sigset.h>
+
+#ifndef __sigset_t_defined
+# define __sigset_t_defined
+typedef __sigset_t sigset_t;
+#endif
+
 
 enum EPOLL_EVENTS
   {
@@ -105,6 +113,16 @@ extern int epoll_ctl (int __epfd, int __
 extern int epoll_wait (int __epfd, struct epoll_event *__events,
 		       int __maxevents, int __timeout);
 
+
+/* Same as epoll_wait, but the thread's signal mask is temporarily
+   and atomically replaced with the one provided as parameter.
+
+   This function is a cancellation point and therefore not marked with
+   __THROW.  */
+extern int epoll_pwait (int __epfd, struct epoll_event *__events,
+			int __maxevents, int __timeout,
+			__const __sigset_t *__ss);
+
 __END_DECLS
 
 #endif /* sys/epoll.h */

	Jakub