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From:   Ayush Jain <ayush.jain3@amd.com>
To:     <akpm@linux-foundation.org>, <shuah@kernel.org>,
        <pasha.tatashin@soleen.com>, <zhansayabagdaulet@gmail.com>,
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        <linux-kernel@vger.kernel.org>, <Narasimhan.V@amd.com>,
        <Santosh.Shukla@amd.com>, Ayush Jain <ayush.jain3@amd.com>
Subject: [PATCH 1/2] selftests: mm: ksm: Fix incorrect evaluation of parameter
Date:   Fri, 28 Jul 2023 11:31:08 +0530
Message-ID: <20230728060109.4403-1-ayush.jain3@amd.com>
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A missing break in kms_tests leads to kselftest hang when the
parameter -s is used.
In current code flow because of missing break in -s, -t parses
args spilled from -s and as -t accepts only valid values as 0,1
so any arg in -s >1 or <0, gets in ksm_test failure

This went undetected since, before the addition of option -t,
the next case -M would immediately break out of the switch
statement but that is no longer the case

Add the missing break statement.

----Before----
./ksm_tests -H -s 100
Invalid merge type

----After----
./ksm_tests -H -s 100
Number of normal pages:    0
Number of huge pages:    50
Total size:    100 MiB
Total time:    0.401732682 s
Average speed:  248.922 MiB/s

Fixes: 9e7cb94ca218 ("selftests: vm: add KSM merging time test")

Signed-off-by: Ayush Jain <ayush.jain3@amd.com>
---
 tools/testing/selftests/mm/ksm_tests.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/tools/testing/selftests/mm/ksm_tests.c b/tools/testing/selftests/mm/ksm_tests.c
index 435acebdc325..380b691d3eb9 100644
--- a/tools/testing/selftests/mm/ksm_tests.c
+++ b/tools/testing/selftests/mm/ksm_tests.c
@@ -831,6 +831,7 @@ int main(int argc, char *argv[])
 				printf("Size must be greater than 0\n");
 				return KSFT_FAIL;
 			}
+			break;
 		case 't':
 			{
 				int tmp = atoi(optarg);
-- 
2.34.1