diff --git a/include/asm-generic/bug.h b/include/asm-generic/bug.h
index 6e794420bd398c7e4848cadebdc107116cfb6af2..b7de3a4eade1c265acc4f92b53d5617d1ae3cb87 100644
--- a/include/asm-generic/bug.h
+++ b/include/asm-generic/bug.h
@@ -156,7 +156,10 @@ extern __printf(1, 2) void __warn_printk(const char *fmt, ...);
#else /* !CONFIG_BUG */
#ifndef HAVE_ARCH_BUG
-#define BUG() do {} while (1)
+#define BUG() do { \
+ do {} while (1); \
+ unreachable(); \
+} while (0)
#endif
#ifndef HAVE_ARCH_BUG_ON
diff --git a/include/linux/irqflags.h b/include/linux/irqflags.h
index 147feebd508cabfa98a1844fb75e2235fb9b56d6..3f003d5fde5341bd789d0d1286109563624090d3 100644
--- a/include/linux/irqflags.h
+++ b/include/linux/irqflags.h
@@ -114,7 +114,7 @@ do { \
# define lockdep_softirq_enter() do { } while (0)
# define lockdep_softirq_exit() do { } while (0)
# define lockdep_hrtimer_enter(__hrtimer) false
-# define lockdep_hrtimer_exit(__context) do { } while (0)
+# define lockdep_hrtimer_exit(__context) do { (void)(__context); } while (0)
# define lockdep_posixtimer_enter() do { } while (0)
# define lockdep_posixtimer_exit() do { } while (0)
# define lockdep_irq_work_enter(__work) do { } while (0)
diff --git a/kernel/time/tick-common.c b/kernel/time/tick-common.c
index fb0fdec8719a13ed5fd5eb66d13027e184dce5de..d88b13076b7944e54fefb2802d914f8f7fe1abf5 100644
--- a/kernel/time/tick-common.c
+++ b/kernel/time/tick-common.c
@@ -7,6 +7,7 @@
* Copyright(C) 2005-2007, Red Hat, Inc., Ingo Molnar
* Copyright(C) 2006-2007, Timesys Corp., Thomas Gleixner
*/
+#include <linux/compiler.h>
#include <linux/cpu.h>
#include <linux/err.h>
#include <linux/hrtimer.h>
@@ -84,7 +85,7 @@ int tick_is_oneshot_available(void)
*/
static void tick_periodic(int cpu)
{
- if (tick_do_timer_cpu == cpu) {
+ if (READ_ONCE(tick_do_timer_cpu) == cpu) {
raw_spin_lock(&jiffies_lock);
write_seqcount_begin(&jiffies_seq);
@@ -215,8 +216,8 @@ static void tick_setup_device(struct tick_device *td,
* If no cpu took the do_timer update, assign it to
* this cpu:
*/
- if (tick_do_timer_cpu == TICK_DO_TIMER_BOOT) {
- tick_do_timer_cpu = cpu;
+ if (READ_ONCE(tick_do_timer_cpu) == TICK_DO_TIMER_BOOT) {
+ WRITE_ONCE(tick_do_timer_cpu, cpu);
tick_next_period = ktime_get();
#ifdef CONFIG_NO_HZ_FULL
/*
@@ -232,7 +233,7 @@ static void tick_setup_device(struct tick_device *td,
!tick_nohz_full_cpu(cpu)) {
tick_take_do_timer_from_boot();
tick_do_timer_boot_cpu = -1;
- WARN_ON(tick_do_timer_cpu != cpu);
+ WARN_ON(READ_ONCE(tick_do_timer_cpu) != cpu);
#endif
}
@@ -406,10 +407,10 @@ void tick_assert_timekeeping_handover(void)
int tick_cpu_dying(unsigned int dying_cpu)
{
/*
- * If the current CPU is the timekeeper, it's the only one that
- * can safely hand over its duty. Also all online CPUs are in
- * stop machine, guaranteed not to be idle, therefore it's safe
- * to pick any online successor.
+ * If the current CPU is the timekeeper, it's the only one that can
+ * safely hand over its duty. Also all online CPUs are in stop
+ * machine, guaranteed not to be idle, therefore there is no
+ * concurrency and it's safe to pick any online successor.
*/
if (tick_do_timer_cpu == dying_cpu)
tick_do_timer_cpu = cpumask_first(cpu_online_mask);
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index 1331216a9cae749cce5e13b7ff4adcf9ba5fefaa..71a792cd893620eebe73eb1a0fc0c4ff5d454344 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -8,6 +8,7 @@
*
* Started by: Thomas Gleixner and Ingo Molnar
*/
+#include <linux/compiler.h>
#include <linux/cpu.h>
#include <linux/err.h>
#include <linux/hrtimer.h>
@@ -204,7 +205,7 @@ static inline void tick_sched_flag_clear(struct tick_sched *ts,
static void tick_sched_do_timer(struct tick_sched *ts, ktime_t now)
{
- int cpu = smp_processor_id();
+ int tick_cpu, cpu = smp_processor_id();
/*
* Check if the do_timer duty was dropped. We don't care about
@@ -216,16 +217,18 @@ static void tick_sched_do_timer(struct tick_sched *ts, ktime_t now)
* If nohz_full is enabled, this should not happen because the
* 'tick_do_timer_cpu' CPU never relinquishes.
*/
- if (IS_ENABLED(CONFIG_NO_HZ_COMMON) &&
- unlikely(tick_do_timer_cpu == TICK_DO_TIMER_NONE)) {
+ tick_cpu = READ_ONCE(tick_do_timer_cpu);
+
+ if (IS_ENABLED(CONFIG_NO_HZ_COMMON) && unlikely(tick_cpu == TICK_DO_TIMER_NONE)) {
#ifdef CONFIG_NO_HZ_FULL
WARN_ON_ONCE(tick_nohz_full_running);
#endif
- tick_do_timer_cpu = cpu;
+ WRITE_ONCE(tick_do_timer_cpu, cpu);
+ tick_cpu = cpu;
}
/* Check if jiffies need an update */
- if (tick_do_timer_cpu == cpu)
+ if (tick_cpu == cpu)
tick_do_update_jiffies64(now);
/*
@@ -610,7 +613,7 @@ bool tick_nohz_cpu_hotpluggable(unsigned int cpu)
* timers, workqueues, timekeeping, ...) on behalf of full dynticks
* CPUs. It must remain online when nohz full is enabled.
*/
- if (tick_nohz_full_running && tick_do_timer_cpu == cpu)
+ if (tick_nohz_full_running && READ_ONCE(tick_do_timer_cpu) == cpu)
return false;
return true;
}
@@ -891,6 +894,7 @@ static ktime_t tick_nohz_next_event(struct tick_sched *ts, int cpu)
{
u64 basemono, next_tick, delta, expires;
unsigned long basejiff;
+ int tick_cpu;
basemono = get_jiffies_update(&basejiff);
ts->last_jiffies = basejiff;
@@ -947,9 +951,9 @@ static ktime_t tick_nohz_next_event(struct tick_sched *ts, int cpu)
* Otherwise we can sleep as long as we want.
*/
delta = timekeeping_max_deferment();
- if (cpu != tick_do_timer_cpu &&
- (tick_do_timer_cpu != TICK_DO_TIMER_NONE ||
- !tick_sched_flag_test(ts, TS_FLAG_DO_TIMER_LAST)))
+ tick_cpu = READ_ONCE(tick_do_timer_cpu);
+ if (tick_cpu != cpu &&
+ (tick_cpu != TICK_DO_TIMER_NONE || !tick_sched_flag_test(ts, TS_FLAG_DO_TIMER_LAST)))
delta = KTIME_MAX;
/* Calculate the next expiry time */
@@ -970,6 +974,7 @@ static void tick_nohz_stop_tick(struct tick_sched *ts, int cpu)
unsigned long basejiff = ts->last_jiffies;
u64 basemono = ts->timer_expires_base;
bool timer_idle = tick_sched_flag_test(ts, TS_FLAG_STOPPED);
+ int tick_cpu;
u64 expires;
/* Make sure we won't be trying to stop it twice in a row. */
@@ -1007,10 +1012,11 @@ static void tick_nohz_stop_tick(struct tick_sched *ts, int cpu)
* do_timer() never gets invoked. Keep track of the fact that it
* was the one which had the do_timer() duty last.
*/
- if (cpu == tick_do_timer_cpu) {
- tick_do_timer_cpu = TICK_DO_TIMER_NONE;
+ tick_cpu = READ_ONCE(tick_do_timer_cpu);
+ if (tick_cpu == cpu) {
+ WRITE_ONCE(tick_do_timer_cpu, TICK_DO_TIMER_NONE);
tick_sched_flag_set(ts, TS_FLAG_DO_TIMER_LAST);
- } else if (tick_do_timer_cpu != TICK_DO_TIMER_NONE) {
+ } else if (tick_cpu != TICK_DO_TIMER_NONE) {
tick_sched_flag_clear(ts, TS_FLAG_DO_TIMER_LAST);
}
@@ -1173,15 +1179,17 @@ static bool can_stop_idle_tick(int cpu, struct tick_sched *ts)
return false;
if (tick_nohz_full_enabled()) {
+ int tick_cpu = READ_ONCE(tick_do_timer_cpu);
+
/*
* Keep the tick alive to guarantee timekeeping progression
* if there are full dynticks CPUs around
*/
- if (tick_do_timer_cpu == cpu)
+ if (tick_cpu == cpu)
return false;
/* Should not happen for nohz-full */
- if (WARN_ON_ONCE(tick_do_timer_cpu == TICK_DO_TIMER_NONE))
+ if (WARN_ON_ONCE(tick_cpu == TICK_DO_TIMER_NONE))
return false;
}
diff --git a/tools/testing/selftests/kselftest.h b/tools/testing/selftests/kselftest.h
index 541bf192e30e6bcec377908643d41d1d1dbf765a..7b89362da4bfd384efe49681451c276ecd78ee16 100644
--- a/tools/testing/selftests/kselftest.h
+++ b/tools/testing/selftests/kselftest.h
@@ -51,6 +51,7 @@
#include <stdarg.h>
#include <string.h>
#include <stdio.h>
+#include <sys/utsname.h>
#endif
#ifndef ARRAY_SIZE
@@ -79,6 +80,9 @@
#define KSFT_XPASS 3
#define KSFT_SKIP 4
+#ifndef __noreturn
+#define __noreturn __attribute__((__noreturn__))
+#endif
#define __printf(a, b) __attribute__((format(printf, a, b)))
/* counters */
@@ -299,13 +303,13 @@ void ksft_test_result_code(int exit_code, const char *test_name,
va_end(args);
}
-static inline int ksft_exit_pass(void)
+static inline __noreturn int ksft_exit_pass(void)
{
ksft_print_cnts();
exit(KSFT_PASS);
}
-static inline int ksft_exit_fail(void)
+static inline __noreturn int ksft_exit_fail(void)
{
ksft_print_cnts();
exit(KSFT_FAIL);
@@ -332,7 +336,7 @@ static inline int ksft_exit_fail(void)
ksft_cnt.ksft_xfail + \
ksft_cnt.ksft_xskip)
-static inline __printf(1, 2) int ksft_exit_fail_msg(const char *msg, ...)
+static inline __noreturn __printf(1, 2) int ksft_exit_fail_msg(const char *msg, ...)
{
int saved_errno = errno;
va_list args;
@@ -347,19 +351,19 @@ static inline __printf(1, 2) int ksft_exit_fail_msg(const char *msg, ...)
exit(KSFT_FAIL);
}
-static inline int ksft_exit_xfail(void)
+static inline __noreturn int ksft_exit_xfail(void)
{
ksft_print_cnts();
exit(KSFT_XFAIL);
}
-static inline int ksft_exit_xpass(void)
+static inline __noreturn int ksft_exit_xpass(void)
{
ksft_print_cnts();
exit(KSFT_XPASS);
}
-static inline __printf(1, 2) int ksft_exit_skip(const char *msg, ...)
+static inline __noreturn __printf(1, 2) int ksft_exit_skip(const char *msg, ...)
{
int saved_errno = errno;
va_list args;
@@ -388,4 +392,21 @@ static inline __printf(1, 2) int ksft_exit_skip(const char *msg, ...)
exit(KSFT_SKIP);
}
+static inline int ksft_min_kernel_version(unsigned int min_major,
+ unsigned int min_minor)
+{
+#ifdef NOLIBC
+ ksft_print_msg("NOLIBC: Can't check kernel version: Function not implemented\n");
+ return 0;
+#else
+ unsigned int major, minor;
+ struct utsname info;
+
+ if (uname(&info) || sscanf(info.release, "%u.%u.", &major, &minor) != 2)
+ ksft_exit_fail_msg("Can't parse kernel version\n");
+
+ return major > min_major || (major == min_major && minor >= min_minor);
+#endif
+}
+
#endif /* __KSELFTEST_H */
diff --git a/tools/testing/selftests/timers/posix_timers.c b/tools/testing/selftests/timers/posix_timers.c
index d49dd3ffd0d96abeaa38cd92f3040ef747726541..c001dd79179d5d28e51d69cbad4c7e9a6a026053 100644
--- a/tools/testing/selftests/timers/posix_timers.c
+++ b/tools/testing/selftests/timers/posix_timers.c
@@ -66,7 +66,7 @@ static int check_diff(struct timeval start, struct timeval end)
diff = end.tv_usec - start.tv_usec;
diff += (end.tv_sec - start.tv_sec) * USECS_PER_SEC;
- if (abs(diff - DELAY * USECS_PER_SEC) > USECS_PER_SEC / 2) {
+ if (llabs(diff - DELAY * USECS_PER_SEC) > USECS_PER_SEC / 2) {
printf("Diff too high: %lld..", diff);
return -1;
}
@@ -184,80 +184,71 @@ static int check_timer_create(int which)
return 0;
}
-int remain;
-__thread int got_signal;
+static pthread_t ctd_thread;
+static volatile int ctd_count, ctd_failed;
-static void *distribution_thread(void *arg)
+static void ctd_sighandler(int sig)
{
- while (__atomic_load_n(&remain, __ATOMIC_RELAXED));
- return NULL;
+ if (pthread_self() != ctd_thread)
+ ctd_failed = 1;
+ ctd_count--;
}
-static void distribution_handler(int nr)
+static void *ctd_thread_func(void *arg)
{
- if (!__atomic_exchange_n(&got_signal, 1, __ATOMIC_RELAXED))
- __atomic_fetch_sub(&remain, 1, __ATOMIC_RELAXED);
-}
-
-/*
- * Test that all running threads _eventually_ receive CLOCK_PROCESS_CPUTIME_ID
- * timer signals. This primarily tests that the kernel does not favour any one.
- */
-static int check_timer_distribution(void)
-{
- int err, i;
- timer_t id;
- const int nthreads = 10;
- pthread_t threads[nthreads];
struct itimerspec val = {
.it_value.tv_sec = 0,
.it_value.tv_nsec = 1000 * 1000,
.it_interval.tv_sec = 0,
.it_interval.tv_nsec = 1000 * 1000,
};
+ timer_t id;
- remain = nthreads + 1; /* worker threads + this thread */
- signal(SIGALRM, distribution_handler);
- err = timer_create(CLOCK_PROCESS_CPUTIME_ID, NULL, &id);
- if (err < 0) {
- ksft_perror("Can't create timer");
- return -1;
- }
- err = timer_settime(id, 0, &val, NULL);
- if (err < 0) {
- ksft_perror("Can't set timer");
- return -1;
- }
+ /* 1/10 seconds to ensure the leader sleeps */
+ usleep(10000);
- for (i = 0; i < nthreads; i++) {
- err = pthread_create(&threads[i], NULL, distribution_thread,
- NULL);
- if (err) {
- ksft_print_msg("Can't create thread: %s (%d)\n",
- strerror(errno), errno);
- return -1;
- }
- }
+ ctd_count = 100;
+ if (timer_create(CLOCK_PROCESS_CPUTIME_ID, NULL, &id))
+ return "Can't create timer\n";
+ if (timer_settime(id, 0, &val, NULL))
+ return "Can't set timer\n";
- /* Wait for all threads to receive the signal. */
- while (__atomic_load_n(&remain, __ATOMIC_RELAXED));
+ while (ctd_count > 0 && !ctd_failed)
+ ;
- for (i = 0; i < nthreads; i++) {
- err = pthread_join(threads[i], NULL);
- if (err) {
- ksft_print_msg("Can't join thread: %s (%d)\n",
- strerror(errno), errno);
- return -1;
- }
- }
+ if (timer_delete(id))
+ return "Can't delete timer\n";
- if (timer_delete(id)) {
- ksft_perror("Can't delete timer");
- return -1;
- }
+ return NULL;
+}
+
+/*
+ * Test that only the running thread receives the timer signal.
+ */
+static int check_timer_distribution(void)
+{
+ const char *errmsg;
- ksft_test_result_pass("check_timer_distribution\n");
+ signal(SIGALRM, ctd_sighandler);
+
+ errmsg = "Can't create thread\n";
+ if (pthread_create(&ctd_thread, NULL, ctd_thread_func, NULL))
+ goto err;
+
+ errmsg = "Can't join thread\n";
+ if (pthread_join(ctd_thread, (void **)&errmsg) || errmsg)
+ goto err;
+
+ if (!ctd_failed)
+ ksft_test_result_pass("check signal distribution\n");
+ else if (ksft_min_kernel_version(6, 3))
+ ksft_test_result_fail("check signal distribution\n");
+ else
+ ksft_test_result_skip("check signal distribution (old kernel)\n");
return 0;
+err:
+ ksft_print_msg("%s", errmsg);
+ return -1;
}
int main(int argc, char **argv)
diff --git a/tools/testing/selftests/timers/valid-adjtimex.c b/tools/testing/selftests/timers/valid-adjtimex.c
index 48b9a803235a80413f0d94d9eb841d9f045779e8..d13ebde203221ae3fa81835fae684c8e180cf111 100644
--- a/tools/testing/selftests/timers/valid-adjtimex.c
+++ b/tools/testing/selftests/timers/valid-adjtimex.c
@@ -21,9 +21,6 @@
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
-
-
-
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
@@ -62,45 +59,47 @@ int clear_time_state(void)
#define NUM_FREQ_OUTOFRANGE 4
#define NUM_FREQ_INVALID 2
+#define SHIFTED_PPM (1 << 16)
+
long valid_freq[NUM_FREQ_VALID] = {
- -499<<16,
- -450<<16,
- -400<<16,
- -350<<16,
- -300<<16,
- -250<<16,
- -200<<16,
- -150<<16,
- -100<<16,
- -75<<16,
- -50<<16,
- -25<<16,
- -10<<16,
- -5<<16,
- -1<<16,
+ -499 * SHIFTED_PPM,
+ -450 * SHIFTED_PPM,
+ -400 * SHIFTED_PPM,
+ -350 * SHIFTED_PPM,
+ -300 * SHIFTED_PPM,
+ -250 * SHIFTED_PPM,
+ -200 * SHIFTED_PPM,
+ -150 * SHIFTED_PPM,
+ -100 * SHIFTED_PPM,
+ -75 * SHIFTED_PPM,
+ -50 * SHIFTED_PPM,
+ -25 * SHIFTED_PPM,
+ -10 * SHIFTED_PPM,
+ -5 * SHIFTED_PPM,
+ -1 * SHIFTED_PPM,
-1000,
- 1<<16,
- 5<<16,
- 10<<16,
- 25<<16,
- 50<<16,
- 75<<16,
- 100<<16,
- 150<<16,
- 200<<16,
- 250<<16,
- 300<<16,
- 350<<16,
- 400<<16,
- 450<<16,
- 499<<16,
+ 1 * SHIFTED_PPM,
+ 5 * SHIFTED_PPM,
+ 10 * SHIFTED_PPM,
+ 25 * SHIFTED_PPM,
+ 50 * SHIFTED_PPM,
+ 75 * SHIFTED_PPM,
+ 100 * SHIFTED_PPM,
+ 150 * SHIFTED_PPM,
+ 200 * SHIFTED_PPM,
+ 250 * SHIFTED_PPM,
+ 300 * SHIFTED_PPM,
+ 350 * SHIFTED_PPM,
+ 400 * SHIFTED_PPM,
+ 450 * SHIFTED_PPM,
+ 499 * SHIFTED_PPM,
};
long outofrange_freq[NUM_FREQ_OUTOFRANGE] = {
- -1000<<16,
- -550<<16,
- 550<<16,
- 1000<<16,
+ -1000 * SHIFTED_PPM,
+ -550 * SHIFTED_PPM,
+ 550 * SHIFTED_PPM,
+ 1000 * SHIFTED_PPM,
};
#define LONG_MAX (~0UL>>1)