From 90accddebef0cf967e67c9d2412082a361d9f2bd Mon Sep 17 00:00:00 2001
From: Markos Chandras <markos.chandras@imgtec.com>
Date: Wed, 10 Oct 2012 16:42:37 +0100
Subject: dup2: Use dup3 if arch does not have the dup2 syscall

Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>

Signed-off-by: Bernhard Reutner-Fischer <rep.dot.nop@gmail.com>
---
 libc/sysdeps/linux/common/dup2.c | 17 +++++++++++++++++
 libc/sysdeps/linux/common/dup3.c |  1 +
 2 files changed, 18 insertions(+)

(limited to 'libc/sysdeps')

diff --git a/libc/sysdeps/linux/common/dup2.c b/libc/sysdeps/linux/common/dup2.c
index 006f06b69..98ac4e305 100644
--- a/libc/sysdeps/linux/common/dup2.c
+++ b/libc/sysdeps/linux/common/dup2.c
@@ -9,7 +9,24 @@
 
 #include <sys/syscall.h>
 #include <unistd.h>
+#if defined __NR_dup3 && !defined __NR_dup2
+# include <fcntl.h>
+extern int __libc_fcntl (int fd, int cmd, ...);
+libc_hidden_proto(__libc_fcntl);
 
+int dup2(int old, int newfd)
+{
+	/*
+	 * Check if old fd is valid before we try
+	 * to ducplicate it. Return it if valid
+	 * or EBADF otherwise
+	 */
+	if (old == newfd)
+		return fcntl(old, F_GETFL, 0) < 0 ? -1 : newfd;
 
+	return dup3(old, newfd, 0);
+}
+#else
 _syscall2(int, dup2, int, oldfd, int, newfd)
+#endif
 libc_hidden_def(dup2)
diff --git a/libc/sysdeps/linux/common/dup3.c b/libc/sysdeps/linux/common/dup3.c
index 0472dd3be..5e8acdc8b 100644
--- a/libc/sysdeps/linux/common/dup3.c
+++ b/libc/sysdeps/linux/common/dup3.c
@@ -12,4 +12,5 @@
 
 #if defined(__NR_dup3)
 _syscall3(int, dup3, int, oldfd, int, newfd, int, flags)
+libc_hidden_def(dup3)
 #endif
-- 
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