diff mbox series

[v4,2/3] selftests/lam: Skip test if LAM is disabled

Message ID 09af68980f1c32f013a9e3b39fde70647f4a8879.1732627541.git.maciej.wieczor-retman@intel.com (mailing list archive)
State New
Headers show
Series selftests/lam: get_user additions and LAM enabled check | expand

Commit Message

Maciej Wieczor-Retman Nov. 26, 2024, 1:34 p.m. UTC 
Until LASS is merged into the kernel [1], LAM is left disabled in the
config file. Running the LAM selftest with disabled LAM only results in
unhelpful output.

Use one of LAM syscalls() to determine whether the kernel was compiled
with LAM support (CONFIG_ADDRESS_MASKING) or not. Skip running the tests
in the latter case.

[1] https://lore.kernel.org/all/20241028160917.1380714-1-alexander.shishkin@linux.intel.com/

Signed-off-by: Maciej Wieczor-Retman <maciej.wieczor-retman@intel.com>
---
Changelog v4:
- Add this patch to the series.

 tools/testing/selftests/x86/lam.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)
diff mbox series

Patch

diff --git a/tools/testing/selftests/x86/lam.c b/tools/testing/selftests/x86/lam.c
index 0ac805125ab2..5aee3e231a96 100644
--- a/tools/testing/selftests/x86/lam.c
+++ b/tools/testing/selftests/x86/lam.c
@@ -124,6 +124,14 @@  static inline int cpu_has_lam(void)
 	return (cpuinfo[0] & (1 << 26));
 }
 
+static inline int kernel_has_lam(void)
+{
+	unsigned long bits;
+
+	syscall(SYS_arch_prctl, ARCH_GET_MAX_TAG_BITS, &bits);
+	return !!bits;
+}
+
 static inline int cpu_has_la57(void)
 {
 	int ret = !!system("cat /proc/cpuinfo | grep -wq la57\n");
@@ -1183,6 +1191,11 @@  int main(int argc, char **argv)
 		return KSFT_SKIP;
 	}
 
+	if (!kernel_has_lam()) {
+		ksft_print_msg("LAM is disabled in the kernel!\n");
+		return KSFT_SKIP;
+	}
+
 	while ((c = getopt(argc, argv, "ht:")) != -1) {
 		switch (c) {
 		case 't':