posix-cpu-timers: Use dedicated flag for CPU timer nanosleep

POSIX CPU timer nanosleep creates a k_itimer on stack and uses the sigq pointer to detect the nanosleep case in the expiry function. Prepare for embedding sigqueue into struct k_itimer by using a dedicated flag for nanosleep. Signed-off-by: Thomas Gleixner <[email protected]> Reviewed-by: Frederic Weisbecker <[email protected]> Acked-by: Peter Zijlstra (Intel) <[email protected]> Link: https://lore.kernel.org/all/[email protected]
sedwards · Nov 7, 2024 · 4cf7bf2 · 4cf7bf2
1 parent bf63568
commit 4cf7bf2
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Showing 2 changed files with 4 additions and 1 deletion.
diff --git a/include/linux/posix-timers.h b/include/linux/posix-timers.h
@@ -42,6 +42,7 @@ static inline int clockid_to_fd(const clockid_t clk)
  * @pid:	Pointer to target task PID
  * @elist:	List head for the expiry list
  * @firing:	Timer is currently firing
+ * @nanosleep:	Timer is used for nanosleep and is not a regular posix-timer
  * @handling:	Pointer to the task which handles expiry
  */
 struct cpu_timer {
@@ -50,6 +51,7 @@ struct cpu_timer {
 	struct pid			*pid;
 	struct list_head		elist;
 	bool				firing;
+	bool				nanosleep;
 	struct task_struct __rcu	*handling;
 };
 

diff --git a/kernel/time/posix-cpu-timers.c b/kernel/time/posix-cpu-timers.c
@@ -596,7 +596,7 @@ static void cpu_timer_fire(struct k_itimer *timer)
 
 	timer->it_status = POSIX_TIMER_DISARMED;
 
-	if (unlikely(timer->sigq == NULL)) {
+	if (unlikely(ctmr->nanosleep)) {
 		/*
 		 * This a special case for clock_nanosleep,
 		 * not a normal timer from sys_timer_create.
@@ -1493,6 +1493,7 @@ static int do_cpu_nanosleep(const clockid_t which_clock, int flags,
 	timer.it_overrun = -1;
 	error = posix_cpu_timer_create(&timer);
 	timer.it_process = current;
+	timer.it.cpu.nanosleep = true;
 
 	if (!error) {
 		static struct itimerspec64 zero_it;