linux-kernel - [tip: timers/core] posix-cpu-timers: Use @now instead of @val for clarity

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [day] [month] [year] [list]

Message-ID: <172235919163.2215.10963718986549637780.tip-bot2@tip-bot2>
Date: Tue, 30 Jul 2024 17:06:31 -0000
From: "tip-bot2 for Thomas Gleixner" <tip-bot2@...utronix.de>
To: linux-tip-commits@...r.kernel.org
Cc: Thomas Gleixner <tglx@...utronix.de>,
 Frederic Weisbecker <frederic@...nel.org>,
 "Peter Zijlstra (Intel)" <peterz@...radead.org>, x86@...nel.org,
 linux-kernel@...r.kernel.org
Subject:
 [tip: timers/core] posix-cpu-timers: Use @now instead of @val for clarity

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

Commit-ID:     c44462661e4c5967c5df451393af727d1886c8ea
Gitweb:        https://git.kernel.org/tip/c44462661e4c5967c5df451393af727d1886c8ea
Author:        Thomas Gleixner <tglx@...utronix.de>
AuthorDate:    Mon, 10 Jun 2024 18:42:22 +02:00
Committer:     Frederic Weisbecker <frederic@...nel.org>
CommitterDate: Mon, 29 Jul 2024 21:57:34 +02:00

posix-cpu-timers: Use @now instead of @val for clarity

posix_cpu_timer_set() uses @val as variable for the current time. That's
confusing at best.

Use @now as anywhere else and rewrite the confusing comment about clock
sampling.

No functional change.

Signed-off-by: Thomas Gleixner <tglx@...utronix.de>
Signed-off-by: Frederic Weisbecker <frederic@...nel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@...radead.org>
---
 kernel/time/posix-cpu-timers.c | 22 +++++++++-------------
 1 file changed, 9 insertions(+), 13 deletions(-)

diff --git a/kernel/time/posix-cpu-timers.c b/kernel/time/posix-cpu-timers.c
index 62e6b90..b1a9a2f 100644
--- a/kernel/time/posix-cpu-timers.c
+++ b/kernel/time/posix-cpu-timers.c
@@ -622,7 +622,7 @@ static int posix_cpu_timer_set(struct k_itimer *timer, int timer_flags,
 {
 	bool sigev_none = timer->it_sigev_notify == SIGEV_NONE;
 	clockid_t clkid = CPUCLOCK_WHICH(timer->it_clock);
-	u64 old_expires, new_expires, old_incr, val;
+	u64 old_expires, new_expires, old_incr, now;
 	struct cpu_timer *ctmr = &timer->it.cpu;
 	struct sighand_struct *sighand;
 	struct task_struct *p;
@@ -674,23 +674,19 @@ static int posix_cpu_timer_set(struct k_itimer *timer, int timer_flags,
 	}
 
 	/*
-	 * We need to sample the current value to convert the new
-	 * value from to relative and absolute, and to convert the
-	 * old value from absolute to relative.  To set a process
-	 * timer, we need a sample to balance the thread expiry
-	 * times (in arm_timer).  With an absolute time, we must
-	 * check if it's already passed.  In short, we need a sample.
+	 * Sample the current clock for saving the previous setting
+	 * and for rearming the timer.
 	 */
 	if (CPUCLOCK_PERTHREAD(timer->it_clock))
-		val = cpu_clock_sample(clkid, p);
+		now = cpu_clock_sample(clkid, p);
 	else
-		val = cpu_clock_sample_group(clkid, p, !sigev_none);
+		now = cpu_clock_sample_group(clkid, p, !sigev_none);
 
 	/* Retrieve the previous expiry value if requested. */
 	if (old) {
 		old->it_value = (struct timespec64){ };
 		if (old_expires)
-			__posix_cpu_timer_get(timer, old, val);
+			__posix_cpu_timer_get(timer, old, now);
 	}
 
 	if (unlikely(ret)) {
@@ -706,7 +702,7 @@ static int posix_cpu_timer_set(struct k_itimer *timer, int timer_flags,
 
 	/* Convert relative expiry time to absolute */
 	if (new_expires && !(timer_flags & TIMER_ABSTIME))
-		new_expires += val;
+		new_expires += now;
 
 	/* Set the new expiry time (might be 0) */
 	cpu_timer_setexpires(ctmr, new_expires);
@@ -716,7 +712,7 @@ static int posix_cpu_timer_set(struct k_itimer *timer, int timer_flags,
 	 * not yet expired and the timer requires signal delivery.
 	 * SIGEV_NONE timers are never armed.
 	 */
-	if (!sigev_none && new_expires && val < new_expires)
+	if (!sigev_none && new_expires && now < new_expires)
 		arm_timer(timer, p);
 
 	unlock_task_sighand(p, &flags);
@@ -736,7 +732,7 @@ static int posix_cpu_timer_set(struct k_itimer *timer, int timer_flags,
 	timer->it_overrun_last = 0;
 	timer->it_overrun = -1;
 
-	if (!sigev_none && val >= new_expires) {
+	if (!sigev_none && now >= new_expires) {
 		if (new_expires != 0) {
 			/*
 			 * The designated time already passed, so we notify