[PATCH] selftests/timers: Skip some posix_timers tests on kernels < 6.13

[PATCH] selftests/timers: Skip some posix_timers tests on kernels < 6.13

[Wake Liu]

Several tests in the posix_timers selftest fail on kernels older
than 6.13. These tests check for timer behavior related to SIG_IGN,
which was refactored in the 6.13 kernel cycle, notably by
commit caf77435dd8a ("signal: Handle ignored signals in
do_sigaction(action != SIG_IGN)").

To ensure the selftests pass on older, stable kernels, gate the
affected tests with a ksft_min_kernel_version(6, 13) check.

Signed-off-by: Wake Liu <wakel@google.com>
---
 tools/testing/selftests/timers/posix_timers.c | 21 +++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/tools/testing/selftests/timers/posix_timers.c b/tools/testing/selftests/timers/posix_timers.c
index f0eceb0faf34..f228e51f8b58 100644
--- a/tools/testing/selftests/timers/posix_timers.c
+++ b/tools/testing/selftests/timers/posix_timers.c
@@ -256,6 +256,11 @@ static void *ignore_thread(void *arg)
 
 static void check_sig_ign(int thread)
 {
+	if (!ksft_min_kernel_version(6, 13)) {
+		// see caf77435dd8a
+		ksft_test_result_skip("Depends on refactor of posix timers in 6.13\n");
+		return;
+	}
 	struct tmrsig tsig = { };
 	struct itimerspec its;
 	unsigned int tid = 0;
@@ -342,6 +347,10 @@ static void check_sig_ign(int thread)
 
 static void check_rearm(void)
 {
+	if (!ksft_min_kernel_version(6, 13)) {
+		ksft_test_result_skip("Depends on refactor of posix timers in 6.13\n");
+		return;
+	}
 	struct tmrsig tsig = { };
 	struct itimerspec its;
 	struct sigaction sa;
@@ -398,6 +407,10 @@ static void check_rearm(void)
 
 static void check_delete(void)
 {
+	if (!ksft_min_kernel_version(6, 13)) {
+		ksft_test_result_skip("Depends on refactor of posix timers in 6.13\n");
+		return;
+	}
 	struct tmrsig tsig = { };
 	struct itimerspec its;
 	struct sigaction sa;
@@ -455,6 +468,10 @@ static inline int64_t calcdiff_ns(struct timespec t1, struct timespec t2)
 
 static void check_sigev_none(int which, const char *name)
 {
+	if (!ksft_min_kernel_version(6, 13)) {
+		ksft_test_result_skip("Depends on refactor of posix timers in 6.13\n");
+		return;
+	}
 	struct timespec start, now;
 	struct itimerspec its;
 	struct sigevent sev;
@@ -493,6 +510,10 @@ static void check_sigev_none(int which, const char *name)
 
 static void check_gettime(int which, const char *name)
 {
+	if (!ksft_min_kernel_version(6, 13)) {
+		ksft_test_result_skip("Depends on refactor of posix timers in 6.13\n");
+		return;
+	}
 	struct itimerspec its, prev;
 	struct timespec start, now;
 	struct sigevent sev;
-- 
2.50.1.703.g449372360f-goog

Re: [PATCH] selftests/timers: Skip some posix_timers tests on kernels < 6.13

[Thomas Gleixner]

On Thu, Aug 07 2025 at 16:50, Wake Liu wrote:
> Several tests in the posix_timers selftest fail on kernels older
> than 6.13. These tests check for timer behavior related to SIG_IGN,
> which was refactored in the 6.13 kernel cycle, notably by
> commit caf77435dd8a ("signal: Handle ignored signals in
> do_sigaction(action != SIG_IGN)").
>
> To ensure the selftests pass on older, stable kernels, gate the
> affected tests with a ksft_min_kernel_version(6, 13) check.

What's the point of emitting 9 times the same skip message?

There is no value at all and this can nicely be solved in main() by
checking the kernel version once, registering either 10 or 19 tests and
not invoking the tests which depend on 6.13+ in the first place, No?

Thanks,

        tglx

[PATCH v2] selftests/timers: Clean up kernel version check in posix_timers

[Wake Liu]

Several tests in the posix_timers selftest which test timer behavior
related to SIG_IGN fail on kernels older than 6.13. This is due to
a refactoring of signal handling in commit caf77435dd8a ("signal:
Handle ignored signals in do_sigaction(action != SIG_IGN)").

A previous attempt to fix this by adding a kernel version check to each
of the nine affected tests was suboptimal, as it resulted in emitting
the same skip message nine times.

Following the suggestion from Thomas Gleixner, this is refactored to
perform a single version check in main(). To satisfy the kselftest
framework's requirement for the test count to match the declared plan,
the plan is now conditionally set to 10 (for older kernels) or 19.

While setting the plan conditionally may seem complex, it is the
better approach to avoid the alternatives: either running tests on
unsupported kernels that are known to fail, or emitting a noisy series
of nine identical skip messages. A single informational message is now
printed instead when the tests are skipped.

Link: https://lore.kernel.org/all/20250807085042.1690931-1-wakel@google.com/
Signed-off-by: Wake Liu <wakel@google.com>
---
 tools/testing/selftests/timers/posix_timers.c | 32 +++++++++++++------
 1 file changed, 22 insertions(+), 10 deletions(-)

diff --git a/tools/testing/selftests/timers/posix_timers.c b/tools/testing/selftests/timers/posix_timers.c
index f0eceb0faf34..a563c438ac79 100644
--- a/tools/testing/selftests/timers/posix_timers.c
+++ b/tools/testing/selftests/timers/posix_timers.c
@@ -18,6 +18,7 @@
 #include <time.h>
 #include <include/vdso/time64.h>
 #include <pthread.h>
+#include <stdbool.h>
 
 #include "../kselftest.h"
 
@@ -670,8 +671,14 @@ static void check_timer_create_exact(void)
 
 int main(int argc, char **argv)
 {
+	bool run_sig_ign_tests = ksft_min_kernel_version(6, 13);
+
 	ksft_print_header();
-	ksft_set_plan(19);
+	if (run_sig_ign_tests) {
+		ksft_set_plan(19);
+	} else {
+		ksft_set_plan(10);
+	}
 
 	ksft_print_msg("Testing posix timers. False negative may happen on CPU execution \n");
 	ksft_print_msg("based timers if other threads run on the CPU...\n");
@@ -695,15 +702,20 @@ int main(int argc, char **argv)
 	check_timer_create(CLOCK_PROCESS_CPUTIME_ID, "CLOCK_PROCESS_CPUTIME_ID");
 	check_timer_distribution();
 
-	check_sig_ign(0);
-	check_sig_ign(1);
-	check_rearm();
-	check_delete();
-	check_sigev_none(CLOCK_MONOTONIC, "CLOCK_MONOTONIC");
-	check_sigev_none(CLOCK_PROCESS_CPUTIME_ID, "CLOCK_PROCESS_CPUTIME_ID");
-	check_gettime(CLOCK_MONOTONIC, "CLOCK_MONOTONIC");
-	check_gettime(CLOCK_PROCESS_CPUTIME_ID, "CLOCK_PROCESS_CPUTIME_ID");
-	check_gettime(CLOCK_THREAD_CPUTIME_ID, "CLOCK_THREAD_CPUTIME_ID");
+	if (run_sig_ign_tests) {
+		check_sig_ign(0);
+		check_sig_ign(1);
+		check_rearm();
+		check_delete();
+		check_sigev_none(CLOCK_MONOTONIC, "CLOCK_MONOTONIC");
+		check_sigev_none(CLOCK_PROCESS_CPUTIME_ID, "CLOCK_PROCESS_CPUTIME_ID");
+		check_gettime(CLOCK_MONOTONIC, "CLOCK_MONOTONIC");
+		check_gettime(CLOCK_PROCESS_CPUTIME_ID, "CLOCK_PROCESS_CPUTIME_ID");
+		check_gettime(CLOCK_THREAD_CPUTIME_ID, "CLOCK_THREAD_CPUTIME_ID");
+	} else {
+		ksft_print_msg("Skipping SIG_IGN tests on kernel < 6.13\n");
+	}
+
 	check_overrun(CLOCK_MONOTONIC, "CLOCK_MONOTONIC");
 	check_overrun(CLOCK_PROCESS_CPUTIME_ID, "CLOCK_PROCESS_CPUTIME_ID");
 	check_overrun(CLOCK_THREAD_CPUTIME_ID, "CLOCK_THREAD_CPUTIME_ID");
-- 
2.51.1.930.gacf6e81ea2-goog

[tip: timers/core] selftests/timers: Clean up kernel version check in posix_timers

[tip-bot2 for Wake Liu]

The following commit has been merged into the timers/core branch of tip:

Commit-ID:     05d89fe7e46a52bb5dde7ac3f07b383895fab528
Gitweb:        https://git.kernel.org/tip/05d89fe7e46a52bb5dde7ac3f07b383895fab528
Author:        Wake Liu <wakel@google.com>
AuthorDate:    Mon, 03 Nov 2025 19:45:02 +08:00
Committer:     Thomas Gleixner <tglx@linutronix.de>
CommitterDate: Fri, 14 Nov 2025 20:34:50 +01:00

selftests/timers: Clean up kernel version check in posix_timers

Several tests in the posix_timers selftest which test timer behavior
related to SIG_IGN fail on kernels older than 6.13. This is due to
a refactoring of signal handling in commit caf77435dd8a ("signal:
Handle ignored signals in do_sigaction(action != SIG_IGN)").

A previous attempt to fix this by adding a kernel version check to each
of the nine affected tests was suboptimal, as it resulted in emitting
the same skip message nine times.

Following the suggestion from Thomas Gleixner, this is refactored to
perform a single version check in main(). To satisfy the kselftest
framework's requirement for the test count to match the declared plan,
the plan is now conditionally set to 10 (for older kernels) or 19.

While setting the plan conditionally may seem complex, it is the
better approach to avoid the alternatives: either running tests on
unsupported kernels that are known to fail, or emitting a noisy series
of nine identical skip messages. A single informational message is now
printed instead when the tests are skipped.

Signed-off-by: Wake Liu <wakel@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20250807085042.1690931-1-wakel@google.com/
Link: https://patch.msgid.link/20251103114502.584940-1-wakel@google.com
---
 tools/testing/selftests/timers/posix_timers.c | 32 ++++++++++++------
 1 file changed, 22 insertions(+), 10 deletions(-)

diff --git a/tools/testing/selftests/timers/posix_timers.c b/tools/testing/selftests/timers/posix_timers.c
index f0eceb0..a563c43 100644
--- a/tools/testing/selftests/timers/posix_timers.c
+++ b/tools/testing/selftests/timers/posix_timers.c
@@ -18,6 +18,7 @@
 #include <time.h>
 #include <include/vdso/time64.h>
 #include <pthread.h>
+#include <stdbool.h>
 
 #include "../kselftest.h"
 
@@ -670,8 +671,14 @@ static void check_timer_create_exact(void)
 
 int main(int argc, char **argv)
 {
+	bool run_sig_ign_tests = ksft_min_kernel_version(6, 13);
+
 	ksft_print_header();
-	ksft_set_plan(19);
+	if (run_sig_ign_tests) {
+		ksft_set_plan(19);
+	} else {
+		ksft_set_plan(10);
+	}
 
 	ksft_print_msg("Testing posix timers. False negative may happen on CPU execution \n");
 	ksft_print_msg("based timers if other threads run on the CPU...\n");
@@ -695,15 +702,20 @@ int main(int argc, char **argv)
 	check_timer_create(CLOCK_PROCESS_CPUTIME_ID, "CLOCK_PROCESS_CPUTIME_ID");
 	check_timer_distribution();
 
-	check_sig_ign(0);
-	check_sig_ign(1);
-	check_rearm();
-	check_delete();
-	check_sigev_none(CLOCK_MONOTONIC, "CLOCK_MONOTONIC");
-	check_sigev_none(CLOCK_PROCESS_CPUTIME_ID, "CLOCK_PROCESS_CPUTIME_ID");
-	check_gettime(CLOCK_MONOTONIC, "CLOCK_MONOTONIC");
-	check_gettime(CLOCK_PROCESS_CPUTIME_ID, "CLOCK_PROCESS_CPUTIME_ID");
-	check_gettime(CLOCK_THREAD_CPUTIME_ID, "CLOCK_THREAD_CPUTIME_ID");
+	if (run_sig_ign_tests) {
+		check_sig_ign(0);
+		check_sig_ign(1);
+		check_rearm();
+		check_delete();
+		check_sigev_none(CLOCK_MONOTONIC, "CLOCK_MONOTONIC");
+		check_sigev_none(CLOCK_PROCESS_CPUTIME_ID, "CLOCK_PROCESS_CPUTIME_ID");
+		check_gettime(CLOCK_MONOTONIC, "CLOCK_MONOTONIC");
+		check_gettime(CLOCK_PROCESS_CPUTIME_ID, "CLOCK_PROCESS_CPUTIME_ID");
+		check_gettime(CLOCK_THREAD_CPUTIME_ID, "CLOCK_THREAD_CPUTIME_ID");
+	} else {
+		ksft_print_msg("Skipping SIG_IGN tests on kernel < 6.13\n");
+	}
+
 	check_overrun(CLOCK_MONOTONIC, "CLOCK_MONOTONIC");
 	check_overrun(CLOCK_PROCESS_CPUTIME_ID, "CLOCK_PROCESS_CPUTIME_ID");
 	check_overrun(CLOCK_THREAD_CPUTIME_ID, "CLOCK_THREAD_CPUTIME_ID");