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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