ltp: Fix overcommit_memory failure

Backport a patch from upstream to fix the following runtime failure.

mem.c:814: INFO: set overcommit_memory to 0
overcommit_memory.c:213: FAIL: alloc passed, expected to fail

(From OE-Core rev: 869f46863e218c2d18ae7b4c0b28775fa07ba8b8)

Signed-off-by: He Zhe <zhe.he@windriver.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Armin Kuster <akuster808@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

2 files changed, 58 insertions, 0 deletions

diff --git a/meta/recipes-extended/ltp/ltp/0001-overcommit_memory-update-for-mm-fix-false-positive-O.patch b/meta/recipes-extended/ltp/ltp/0001-overcommit_memory-update-for-mm-fix-false-positive-O.patch
new file mode 100644
index 0000000000..bed84712a1
--- /dev/null
+++ b/meta/recipes-extended/ltp/ltp/0001-overcommit_memory-update-for-mm-fix-false-positive-O.patch
@@ -0,0 +1,57 @@
+From d656a447893dccc310c975a239f482278550c3e0 Mon Sep 17 00:00:00 2001
+From: Jan Stancek <jstancek@redhat.com>
+Date: Tue, 21 May 2019 10:10:44 +0200
+Subject: [PATCH] overcommit_memory: update for "mm: fix false-positive
+ OVERCOMMIT_GUESS failures"
+
+commit 8c7829b04c52 ("mm: fix false-positive OVERCOMMIT_GUESS failures")
+changes logic of __vm_enough_memory(), simplifying it to:
+    When in GUESS mode, catch wild allocations by comparing their request
+    size to total amount of ram and swap in the system.
+
+Testcase currently allocates mem_total + swap_total, which doesn't trigger
+new condition. Make it more extreme, but assuming free_total / 2 will PASS,
+and 2*sum_total will FAIL.
+
+Signed-off-by: Jan Stancek <jstancek@redhat.com>
+Acked-by: Cyril Hrubis <chrubis@suse.cz>
+
+Upstream-Status: Backport [https://github.com/linux-test-project/ltp/commit/d656a447893dccc310c975a239f482278550c3e0]
+Signed-off-by: He Zhe <zhe.he@windriver.com>
+---
+ testcases/kernel/mem/tunable/overcommit_memory.c | 11 ++++-------
+ 1 file changed, 4 insertions(+), 7 deletions(-)
+
+diff --git a/testcases/kernel/mem/tunable/overcommit_memory.c b/testcases/kernel/mem/tunable/overcommit_memory.c
+index 555298f..345764d 100644
+--- a/testcases/kernel/mem/tunable/overcommit_memory.c
++++ b/testcases/kernel/mem/tunable/overcommit_memory.c
+@@ -36,11 +36,10 @@
+  *
+  * The program is designed to test the two tunables:
+  *
+- * When overcommit_memory = 0, allocatable memory can't overextends
+- * the amount of free memory. I choose the three cases:
++ * When overcommit_memory = 0, allocatable memory can't overextend
++ * the amount of total memory:
+  * a. less than free_total:    free_total / 2, alloc should pass.
+- * b. greater than free_total: free_total * 2, alloc should fail.
+- * c. equal to sum_total:      sum_tatal,      alloc should fail
++ * b. greater than sum_total:   sum_total * 2, alloc should fail.
+  *
+  * When overcommit_memory = 1, it can alloc enough much memory, I
+  * choose the three cases:
+@@ -164,9 +163,7 @@ static void overcommit_memory_test(void)
+ 
+        update_mem();
+        alloc_and_check(free_total / 2, EXPECT_PASS);
+-       update_mem();
+-       alloc_and_check(free_total * 2, EXPECT_FAIL);
+-       alloc_and_check(sum_total, EXPECT_FAIL);
++       alloc_and_check(sum_total * 2, EXPECT_FAIL);
+ 
+        /* start to test overcommit_memory=1 */
+        set_sys_tune("overcommit_memory", 1, 1);
+-- 
+2.7.4
+
diff --git a/meta/recipes-extended/ltp/ltp_20190517.bb b/meta/recipes-extended/ltp/ltp_20190517.bb
index 4650715607..5915b1c72a 100644
--- a/meta/recipes-extended/ltp/ltp_20190517.bb
+++ b/meta/recipes-extended/ltp/ltp_20190517.bb
@@ -49,6 +49,7 @@ SRC_URI = "git://github.com/linux-test-project/ltp.git \
            file://0001-testcases-use-python3-everywhere-to-run-python-scrip.patch \
            file://0001-syscall-rt_sigtimedwait01-Fix-wrong-sigset-length-fo.patch \
            file://0001-cve-2017-17052-Avoid-unsafe-exits-in-threads.patch \
+           file://0001-overcommit_memory-update-for-mm-fix-false-positive-O.patch \
            "
 
 S = "${WORKDIR}/git"