linux-kernel - [tip: locking/urgent] futex: Get rid of the val2 conditional dance

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Date:   Thu, 06 May 2021 18:20:45 -0000
From:   "tip-bot2 for Thomas Gleixner" <tip-bot2@...utronix.de>
To:     linux-tip-commits@...r.kernel.org
Cc:     Thomas Gleixner <tglx@...utronix.de>,
        "Peter Zijlstra (Intel)" <peterz@...radead.org>, x86@...nel.org,
        linux-kernel@...r.kernel.org
Subject: [tip: locking/urgent] futex: Get rid of the val2 conditional dance

The following commit has been merged into the locking/urgent branch of tip:

Commit-ID:     b097d5ed33561507eeffc77120a8c16c2f0f2c4c
Gitweb:        https://git.kernel.org/tip/b097d5ed33561507eeffc77120a8c16c2f0f2c4c
Author:        Thomas Gleixner <tglx@...utronix.de>
AuthorDate:    Thu, 22 Apr 2021 21:44:20 +02:00
Committer:     Thomas Gleixner <tglx@...utronix.de>
CommitterDate: Thu, 06 May 2021 20:19:04 +02:00

futex: Get rid of the val2 conditional dance

There is no point in checking which FUTEX operand treats the utime pointer
as 'val2' argument because that argument to do_futex() is only used by
exactly these operands.

So just handing it in unconditionally is not making any difference, but
removes a lot of pointless gunk.

Signed-off-by: Thomas Gleixner <tglx@...utronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@...radead.org>
Link: https://lore.kernel.org/r/20210422194705.125957049@linutronix.de

---
 kernel/futex.c | 16 ++--------------
 1 file changed, 2 insertions(+), 14 deletions(-)

diff --git a/kernel/futex.c b/kernel/futex.c
index b0f5304..4ddfdce 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -3764,7 +3764,6 @@ SYSCALL_DEFINE6(futex, u32 __user *, uaddr, int, op, u32, val,
 {
 	struct timespec64 ts;
 	ktime_t t, *tp = NULL;
-	u32 val2 = 0;
 	int cmd = op & FUTEX_CMD_MASK;
 
 	if (utime && (cmd == FUTEX_WAIT || cmd == FUTEX_LOCK_PI ||
@@ -3784,15 +3783,8 @@ SYSCALL_DEFINE6(futex, u32 __user *, uaddr, int, op, u32, val,
 			t = timens_ktime_to_host(CLOCK_MONOTONIC, t);
 		tp = &t;
 	}
-	/*
-	 * requeue parameter in 'utime' if cmd == FUTEX_*_REQUEUE_*.
-	 * number of waiters to wake in 'utime' if cmd == FUTEX_WAKE_OP.
-	 */
-	if (cmd == FUTEX_REQUEUE || cmd == FUTEX_CMP_REQUEUE ||
-	    cmd == FUTEX_CMP_REQUEUE_PI || cmd == FUTEX_WAKE_OP)
-		val2 = (u32) (unsigned long) utime;
 
-	return do_futex(uaddr, op, val, tp, uaddr2, val2, val3);
+	return do_futex(uaddr, op, val, tp, uaddr2, (unsigned long)utime, val3);
 }
 
 #ifdef CONFIG_COMPAT
@@ -3960,7 +3952,6 @@ SYSCALL_DEFINE6(futex_time32, u32 __user *, uaddr, int, op, u32, val,
 {
 	struct timespec64 ts;
 	ktime_t t, *tp = NULL;
-	int val2 = 0;
 	int cmd = op & FUTEX_CMD_MASK;
 
 	if (utime && (cmd == FUTEX_WAIT || cmd == FUTEX_LOCK_PI ||
@@ -3978,11 +3969,8 @@ SYSCALL_DEFINE6(futex_time32, u32 __user *, uaddr, int, op, u32, val,
 			t = timens_ktime_to_host(CLOCK_MONOTONIC, t);
 		tp = &t;
 	}
-	if (cmd == FUTEX_REQUEUE || cmd == FUTEX_CMP_REQUEUE ||
-	    cmd == FUTEX_CMP_REQUEUE_PI || cmd == FUTEX_WAKE_OP)
-		val2 = (int) (unsigned long) utime;
 
-	return do_futex(uaddr, op, val, tp, uaddr2, val2, val3);
+	return do_futex(uaddr, op, val, tp, uaddr2, (unsigned long)utime, val3);
 }
 #endif /* CONFIG_COMPAT_32BIT_TIME */