From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Shuah Khan <skhan@linuxfoundation.org>,
        Naresh Kamboju <naresh.kamboju@linaro.org>
Subject: [PATCH 5.10 02/43] selftests: x86: fix [-Wstringop-overread] warn in test_process_vm_readv()
Date:   Mon, 10 Jan 2022 08:22:59 +0100
Message-Id: <20220110071817.417485930@linuxfoundation.org>
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From: Shuah Khan <skhan@linuxfoundation.org>

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@linuxfoundation.org>
Cc: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 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
@@ -497,7 +497,7 @@ 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");