* login/login_tty.c (login_tty): The Linux kernel can return EBUSY

	for dup2 in case another thread races with the current one.  Retry
	in this case.

2 files changed, 11 insertions, 3 deletions

diff --git a/ChangeLog b/ChangeLog
index e4ad3c8a90..eed866ff58 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,9 @@
 2007-10-04  Ulrich Drepper  <drepper@redhat.com>
 
+	* login/login_tty.c (login_tty): The Linux kernel can return EBUSY
+	for dup2 in case another thread races with the current one.  Retry
+	in this case.
+
 	* misc/error.h: Remove support for use outside of libc.  We have to
 	include <features.h> now.  Include <bits/error.h> if possible.
 	* misc/bits/error.h: New file.
diff --git a/login/login_tty.c b/login/login_tty.c
index 1bb1703267..2ba276d4a9 100644
--- a/login/login_tty.c
+++ b/login/login_tty.c
@@ -31,6 +31,7 @@
 static char sccsid[] = "@(#)login_tty.c	8.1 (Berkeley) 6/4/93";
 #endif /* LIBC_SCCS and not lint */
 
+#include <errno.h>
 #include <sys/param.h>
 #include <sys/ioctl.h>
 #include <unistd.h>
@@ -63,9 +64,12 @@ login_tty(fd)
 	    }
 	}
 #endif
-	(void) dup2(fd, 0);
-	(void) dup2(fd, 1);
-	(void) dup2(fd, 2);
+	while (dup2(fd, 0) == -1 && errno == EBUSY)
+	  ;
+	while (dup2(fd, 1) == -1 && errno == EBUSY)
+	  ;
+	while (dup2(fd, 2) == -1 && errno == EBUSY)
+	  ;
 	if (fd > 2)
 		(void) close(fd);
 	return (0);