[LTP] [PATCH v2] kcmp03: Add check for KCMP_SYSVSEM before running test

[Dorinda Bassey]

This commit introduces a new function
`is_kcmp_supported()` to check if the kernel supports the
`KCMP_SYSVSEM` operation. In the `verify_kcmp()` function,
we add logic to detect when the kernel does not support
`KCMP_SYSVSEM` and skip the test for that case with a TCONF
result. This ensures that the test does not fail when the
Kconfig that supports `KCMP_SYSVSEM` is unavailable.

Signed-off-by: Dorinda Bassey <dbassey@redhat.com>
---
v2 changes
fix coding style
use `kcmp()` instead of `syscall()`
do `is_kcmp_supported()` check in the setup and
cache result
use `tst_res` instead of `tst_brk`

 testcases/kernel/syscalls/kcmp/kcmp03.c | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/testcases/kernel/syscalls/kcmp/kcmp03.c b/testcases/kernel/syscalls/kcmp/kcmp03.c
index 37d5118d5..8610cea46 100644
--- a/testcases/kernel/syscalls/kcmp/kcmp03.c
+++ b/testcases/kernel/syscalls/kcmp/kcmp03.c
@@ -42,9 +42,19 @@ static struct tcase {
 	{ARGS(CLONE_SYSVSEM, KCMP_SYSVSEM)}
 };
 
+static int is_kcmp_supported_flag = -1;
+
+static int is_kcmp_supported(void)
+{
+	return kcmp(getpid(), getpid(), KCMP_SYSVSEM, 0, 0) == 0;
+}
+
 static void setup(void)
 {
 	stack = SAFE_MALLOC(STACK_SIZE);
+
+	if (is_kcmp_supported_flag == -1)
+		is_kcmp_supported_flag = is_kcmp_supported();
 }
 
 static void cleanup(void)
@@ -64,6 +74,14 @@ static void verify_kcmp(unsigned int n)
 	int res;
 	struct tcase *tc = &tcases[n];
 
+    // Handle the case for KCMP_SYSVSEM specifically
+	if (tc->kcmp_type == KCMP_SYSVSEM) {
+		if (is_kcmp_supported_flag == 0) {
+			tst_res(TCONF, "Kernel does not support KCMP_SYSVSEM, skipping test.");
+			return;
+		}
+	}
+
 	pid1 = getpid();
 	tst_res(TINFO, "Testing %s", tc->desc);
 
-- 
2.48.1