linux-kernel - [PATCH 2/3] futex: Store time as ktime

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Message-Id: <20251110-restart-block-expiration-v1-2-5d39cc93df4f@linutronix.de>
Date: Mon, 10 Nov 2025 10:38:52 +0100
From: Thomas Weißschuh <thomas.weissschuh@...utronix.de>
To: Alexander Viro <viro@...iv.linux.org.uk>, 
 Christian Brauner <brauner@...nel.org>, Jan Kara <jack@...e.cz>, 
 Thomas Gleixner <tglx@...utronix.de>, Ingo Molnar <mingo@...hat.com>, 
 Peter Zijlstra <peterz@...radead.org>, Darren Hart <dvhart@...radead.org>, 
 Davidlohr Bueso <dave@...olabs.net>, 
 André Almeida <andrealmeid@...lia.com>, 
 Anna-Maria Behnsen <anna-maria@...utronix.de>, 
 Frederic Weisbecker <frederic@...nel.org>
Cc: linux-fsdevel@...r.kernel.org, linux-kernel@...r.kernel.org, 
 Thomas Weißschuh <thomas.weissschuh@...utronix.de>
Subject: [PATCH 2/3] futex: Store time as ktime_t in restart block

The futex core uses ktime_t to represent times,
use that also for the restart block.

This also allows the simplification of the accessors.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@...utronix.de>
---
 include/linux/restart_block.h | 2 +-
 kernel/futex/waitwake.c       | 9 ++++-----
 2 files changed, 5 insertions(+), 6 deletions(-)

diff --git a/include/linux/restart_block.h b/include/linux/restart_block.h
index 0798a4ae67c6c75749c38c4673ab8ea012261319..3c2bd13f609120a8a914f6e738ffea97bf72c32d 100644
--- a/include/linux/restart_block.h
+++ b/include/linux/restart_block.h
@@ -33,7 +33,7 @@ struct restart_block {
 			u32 val;
 			u32 flags;
 			u32 bitset;
-			u64 time;
+			ktime_t time;
 			u32 __user *uaddr2;
 		} futex;
 		/* For nanosleep */
diff --git a/kernel/futex/waitwake.c b/kernel/futex/waitwake.c
index e2bbe5509ec27a18785227358d4ff8d8f913ddc1..1c2dd03f11ec4e5d34d1a9f67ef01e05604b3bac 100644
--- a/kernel/futex/waitwake.c
+++ b/kernel/futex/waitwake.c
@@ -738,12 +738,11 @@ int futex_wait(u32 __user *uaddr, unsigned int flags, u32 val, ktime_t *abs_time
 static long futex_wait_restart(struct restart_block *restart)
 {
 	u32 __user *uaddr = restart->futex.uaddr;
-	ktime_t t, *tp = NULL;
+	ktime_t *tp = NULL;
+
+	if (restart->futex.flags & FLAGS_HAS_TIMEOUT)
+		tp = &restart->futex.time;
 
-	if (restart->futex.flags & FLAGS_HAS_TIMEOUT) {
-		t = restart->futex.time;
-		tp = &t;
-	}
 	restart->fn = do_no_restart_syscall;
 
 	return (long)futex_wait(uaddr, restart->futex.flags,

-- 
2.51.0