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[PATCH] Make bindresvport() function to multithread-safe
- From: Peng Haitao <penght at cn dot fujitsu dot com>
- To: Ulrich Drepper <drepper at gmail dot com>
- Cc: libc-alpha at sourceware dot org
- Date: Fri, 17 Feb 2012 14:00:45 +0800
- Subject: [PATCH] Make bindresvport() function to multithread-safe
bindresvport() uses two static variables port and startport which are 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 variables will be
protected.
Signed-off-by: Peng Haitao <penght@cn.fujitsu.com>
---
ChangeLog | 4 ++++
sunrpc/bindrsvprt.c | 10 ++++++++++
2 files changed, 14 insertions(+), 0 deletions(-)
diff --git a/ChangeLog b/ChangeLog
index 58d02d6..42bfe3a 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+2012-02-16 Peng Haitao <penght@cn.fujitsu.com>
+
+ * sunrpc/bindrsvprt.c: Add lock to protect static variable.
+
2012-02-16 Richard Henderson <rth@redhat.com>
* sysdeps/s390/s390-32/crti.S, sysdeps/s390/s390-32/crtn.S: New files.
diff --git a/sunrpc/bindrsvprt.c b/sunrpc/bindrsvprt.c
index d493c9f..f2fdefb 100644
--- a/sunrpc/bindrsvprt.c
+++ b/sunrpc/bindrsvprt.c
@@ -35,6 +35,12 @@
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
+#include <bits/libc-lock.h>
+
+/*
+ * Locks the static variables in this file.
+ */
+__libc_lock_define_initialized (static, lock);
/*
* Bind a socket to a privileged IP port
@@ -64,6 +70,8 @@ bindresvport (int sd, struct sockaddr_in *sin)
return -1;
}
+ __libc_lock_lock (lock);
+
if (port == 0)
{
port = (__getpid () % NPORTS) + STARTPORT;
@@ -94,6 +102,8 @@ bindresvport (int sd, struct sockaddr_in *sin)
goto again;
}
+ __libc_lock_unlock (lock);
+
return res;
}
libc_hidden_def (bindresvport)
--
1.7.1
--
Best Regards,
Peng