The following commit has been merged into the timers/core branch of tip:
Commit-ID: 8e63360d869913265e5e4b623dcd23feff9fd000
Gitweb: https://git.kernel.org/tip/8e63360d869913265e5e4b623dcd23feff9fd000
Author: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
AuthorDate: Mon, 10 Mar 2025 09:11:42 +01:00
Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitterDate: Thu, 13 Mar 2025 12:07:18 +01:00
selftests/timers/posix-timers: Add a test for exact allocation mode
The exact timer ID allocation mode is used by CRIU to restore timers with a
given ID. Add a test case for it.
It's skipped on older kernels when the prctl() fails.
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Reviewed-by: Frederic Weisbecker <frederic@xxxxxxxxxx>
Link: https://lore.kernel.org/all/8734fl2tkx.ffs@tglx
---
tools/testing/selftests/timers/posix_timers.c | 73 +++++++++++++++++-
1 file changed, 72 insertions(+), 1 deletion(-)
diff --git a/tools/testing/selftests/timers/posix_timers.c b/tools/testing/selftests/timers/posix_timers.c
index 9814b3a..f0eceb0 100644
--- a/tools/testing/selftests/timers/posix_timers.c
+++ b/tools/testing/selftests/timers/posix_timers.c
@@ -7,6 +7,7 @@
* Kernel loop code stolen from Steven Rostedt <srostedt@xxxxxxxxxx>
*/
#define _GNU_SOURCE
+#include <sys/prctl.h>
#include <sys/time.h>
#include <sys/types.h>
#include <stdio.h>
@@ -599,14 +600,84 @@ static void check_overrun(int which, const char *name)
"check_overrun %s\n", name);
}
+#include <sys/syscall.h>
+
+static int do_timer_create(int *id)
+{
+ return syscall(__NR_timer_create, CLOCK_MONOTONIC, NULL, id);
+}
+
+static int do_timer_delete(int id)
+{
+ return syscall(__NR_timer_delete, id);
+}
+
+#ifndef PR_TIMER_CREATE_RESTORE_IDS
+# define PR_TIMER_CREATE_RESTORE_IDS 77
+# define PR_TIMER_CREATE_RESTORE_IDS_OFF 0
+# define PR_TIMER_CREATE_RESTORE_IDS_ON 1
+# define PR_TIMER_CREATE_RESTORE_IDS_GET 2
+#endif
+
+static void check_timer_create_exact(void)
+{
+ int id;
+
+ if (prctl(PR_TIMER_CREATE_RESTORE_IDS, PR_TIMER_CREATE_RESTORE_IDS_ON, 0, 0, 0)) {
+ switch (errno) {
+ case EINVAL:
+ ksft_test_result_skip("check timer create exact, not supported\n");
+ return;
+ default:
+ ksft_test_result_skip("check timer create exact, errno = %d\n", errno);
+ return;
+ }
+ }
+
+ if (prctl(PR_TIMER_CREATE_RESTORE_IDS, PR_TIMER_CREATE_RESTORE_IDS_GET, 0, 0, 0) != 1)
+ fatal_error(NULL, "prctl(GET) failed\n");
+
+ id = 8;
+ if (do_timer_create(&id) < 0)
+ fatal_error(NULL, "timer_create()");
+
+ if (do_timer_delete(id))
+ fatal_error(NULL, "timer_delete()");
+
+ if (prctl(PR_TIMER_CREATE_RESTORE_IDS, PR_TIMER_CREATE_RESTORE_IDS_OFF, 0, 0, 0))
+ fatal_error(NULL, "prctl(OFF)");
+
+ if (prctl(PR_TIMER_CREATE_RESTORE_IDS, PR_TIMER_CREATE_RESTORE_IDS_GET, 0, 0, 0) != 0)
+ fatal_error(NULL, "prctl(GET) failed\n");
+
+ if (id != 8) {
+ ksft_test_result_fail("check timer create exact %d != 8\n", id);
+ return;
+ }
+
+ /* Validate that it went back to normal mode and allocates ID 9 */
+ if (do_timer_create(&id) < 0)
+ fatal_error(NULL, "timer_create()");
+
+ if (do_timer_delete(id))
+ fatal_error(NULL, "timer_delete()");
+
+ if (id == 9)
+ ksft_test_result_pass("check timer create exact\n");
+ else
+ ksft_test_result_fail("check timer create exact. Disabling failed.\n");
+}
+
int main(int argc, char **argv)
{
ksft_print_header();
- ksft_set_plan(18);
+ ksft_set_plan(19);
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");
+ check_timer_create_exact();
+
check_itimer(ITIMER_VIRTUAL, "ITIMER_VIRTUAL");
check_itimer(ITIMER_PROF, "ITIMER_PROF");
check_itimer(ITIMER_REAL, "ITIMER_REAL");
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