[PATCH v4] Make bindresvport() function to multithread-safe

[Peng Haitao <penght at cn dot fujitsu dot com>]

bindresvport() uses a static variable port which is not protected.
It is not safe when in multithread circumstance.

bindresvport() select a port number from the range 512 to 1023, when in
multithread circumstance, the port may be 1024. So the static variable
will be protected.

Signed-off-by: Peng Haitao <penght@cn.fujitsu.com>
---
 ChangeLog           |  6 ++++++
 sunrpc/bindrsvprt.c |  8 +++++---
 sunrpc/bindrsvprt.h | 37 +++++++++++++++++++++++++++++++++++++
 3 files changed, 48 insertions(+), 3 deletions(-)
 create mode 100644 sunrpc/bindrsvprt.h

diff --git a/ChangeLog b/ChangeLog
index 3004989..8db0157 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2012-09-27  Peng Haitao  <penght@cn.fujitsu.com>
+
+	[BZ #13763]
+	* sunrpc/bindrsvprt.c: Add __thread when define static's port,
+	getpid() is changed to gettid() in Linux.
+
 2012-09-27  David S. Miller  <davem@davemloft.net>
 
 	[BZ #14376]
diff --git a/sunrpc/bindrsvprt.c b/sunrpc/bindrsvprt.c
index d493c9f..ab835a1 100644
--- a/sunrpc/bindrsvprt.c
+++ b/sunrpc/bindrsvprt.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2010, Oracle America, Inc.
+ * Copyright (c) 2010-2012, Oracle America, Inc.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
@@ -36,13 +36,15 @@
 #include <sys/socket.h>
 #include <netinet/in.h>
 
+#include "bindrsvprt.h"
+
 /*
  * Bind a socket to a privileged IP port
  */
 int
 bindresvport (int sd, struct sockaddr_in *sin)
 {
-  static short port;
+  static __thread short port;
   struct sockaddr_in myaddr;
   int i;
 
@@ -66,7 +68,7 @@ bindresvport (int sd, struct sockaddr_in *sin)
 
   if (port == 0)
     {
-      port = (__getpid () % NPORTS) + STARTPORT;
+      port = (get_port () % NPORTS) + STARTPORT;
     }
 
   /* Initialize to make gcc happy.  */
diff --git a/sunrpc/bindrsvprt.h b/sunrpc/bindrsvprt.h
new file mode 100644
index 0000000..221f811
--- /dev/null
+++ b/sunrpc/bindrsvprt.h
@@ -0,0 +1,37 @@
+/* Copyright (C) 2012 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, see
+   <http://www.gnu.org/licenses/>.  */
+
+#ifdef __linux__
+#ifdef INTERNAL_SYSCALL
+#define get_port()                            \
+ ({                                           \
+  INTERNAL_SYSCALL_DECL (err);                \
+  short __port;                               \
+  __port = INTERNAL_SYSCALL (gettid, err, 0); \
+  __port;                                     \
+ })
+#else
+#define get_port()                            \
+ ({                                           \
+  short __port;                               \
+  __port = INLINE_SYSCALL (gettid, 0);        \
+  __port;                                     \
+ })
+#endif /* INTERNAL_SYSCALL */
+#else
+#define get_port() __getpid()
+#endif /* __linux__ */
-- 
1.7.11.4