From: Rich Felker <dalias@aerifal.cx>
Date: Thu, 21 Apr 2011 01:05:10 +0000 (-0400)
Subject: workaround bug in linux dup2
X-Git-Url: http://nsz.repo.hu/git/?p=musl;a=commitdiff_plain;h=f9a6372a98cc4d1b70400b2e7238e1f9eae50558;hp=10d7561db5d51231939fa0b42d17eaac2bff6938

workaround bug in linux dup2

the linux documentation for dup2 says it can fail with EBUSY due to a
race condition with open and dup in the kernel. shield applications
(and the rest of libc) from this nonsense by looping until it succeeds
---

diff --git a/src/unistd/dup2.c b/src/unistd/dup2.c
index 7945f853..87a0d445 100644
--- a/src/unistd/dup2.c
+++ b/src/unistd/dup2.c
@@ -1,7 +1,10 @@
 #include <unistd.h>
+#include <errno.h>
 #include "syscall.h"
 
 int dup2(int old, int new)
 {
-	return syscall(SYS_dup2, old, new);
+	int r;
+	while ((r=__syscall(SYS_dup2, old, new))==-EBUSY);
+	return __syscall_ret(r);
 }