ltp: fix hanging issue for gdb01 case

If gdb01 testcase runs as background process, gdb can receive SIGTTOU
and then the case gets stuck. Replace stdin with /dev/null to fix this
issue. The patch is backported from upstream.

(From OE-Core rev: b38a44e3ca30a8fe83bdccb4ee2b7748b3f7f223)

Signed-off-by: Yi Zhao <yi.zhao@windriver.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/recipes-extended/ltp/ltp/0038-commands-gdb01-replace-stdin-with-dev-null.patch

@@ -0,0 +1,34 @@
+From 2f6ab8f694b26b7f2566624f6d1f23788d6ab8a0 Mon Sep 17 00:00:00 2001
+From: Jan Stancek <jstancek@redhat.com>
+Date: Mon, 11 Sep 2017 12:57:58 +0200
+Subject: [PATCH] commands/gdb01: replace stdin with /dev/null
+
+If this testcase runs as background process, gdb can receive
+SIGTTOU and then testcase gets stuck.
+
+Signed-off-by: Jan Stancek <jstancek@redhat.com>
+
+Upstream-Status: Backport
+[https://github.com/linux-test-project/ltp/commit/2f6ab8f694b26b7f2566624f6d1f23788d6ab8a0]
+
+Signed-off-by: Yi Zhao <yi.zhao@windriver.com>
+---
+ testcases/commands/gdb/gdb01.sh | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/testcases/commands/gdb/gdb01.sh b/testcases/commands/gdb/gdb01.sh
+index 07ae36f..e3a5b51 100755
+--- a/testcases/commands/gdb/gdb01.sh
++++ b/testcases/commands/gdb/gdb01.sh
+@@ -29,7 +29,7 @@ TST_NEEDS_CMDS="gdb /bin/cat"
+ 
+ simple_test()
+ {
+-	gdb /bin/cat -ex "run /etc/passwd" -ex quit
++	gdb /bin/cat -ex "run /etc/passwd" -ex quit < /dev/null
+ 	RC=$?
+ 	if [ $RC -eq 0 ] ; then
+ 		tst_res TPASS "gdb attached to process and completed run"
+-- 
+2.7.4
+

meta/recipes-extended/ltp/ltp_20170516.bb

@@ -49,6 +49,7 @@ SRC_URI = "git://github.com/linux-test-project/ltp.git \
            file://0035-fix-test_proc_kill-hang.patch \
            file://0036-testcases-network-nfsv4-acl-acl1.c-Security-fix-on-s.patch \
            file://0037-ltp-fix-PAGE_SIZE-redefinition-and-O_CREAT-undeclear.patch \
+           file://0038-commands-gdb01-replace-stdin-with-dev-null.patch \
            "
 
 S = "${WORKDIR}/git"