[PATCH 5.4 03/34] selftests: x86: fix [-Wstringop-overread] warn in test_process_vm_readv()

[Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>]

From: Shuah Khan <skhan@xxxxxxxxxxxxxxxxxxx>

commit dd40f44eabe1e122c6852fabb298aac05b083fce upstream.

Fix the following [-Wstringop-overread] by passing in the variable
instead of the value.

test_vsyscall.c: In function ‘test_process_vm_readv’:
test_vsyscall.c:500:22: warning: ‘__builtin_memcmp_eq’ specified bound 4096 exceeds source size 0 [-Wstringop-overread]
  500 |                 if (!memcmp(buf, (const void *)0xffffffffff600000, 4096)) {
      |                      ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Signed-off-by: Shuah Khan <skhan@xxxxxxxxxxxxxxxxxxx>
Cc: Naresh Kamboju <naresh.kamboju@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 tools/testing/selftests/x86/test_vsyscall.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/tools/testing/selftests/x86/test_vsyscall.c
+++ b/tools/testing/selftests/x86/test_vsyscall.c
@@ -480,7 +480,7 @@ static int test_process_vm_readv(void)
 	}
 
 	if (vsyscall_map_r) {
-		if (!memcmp(buf, (const void *)0xffffffffff600000, 4096)) {
+		if (!memcmp(buf, remote.iov_base, sizeof(buf))) {
 			printf("[OK]\tIt worked and read correct data\n");
 		} else {
 			printf("[FAIL]\tIt worked but returned incorrect data\n");