linux-kernel - [PATCH] generic arch_futex_atomic_op

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Message-ID: <7b963f9a-21b1-4c6d-3ece-556d018508b4@virtuozzo.com>
Date:   Mon, 15 Jul 2019 13:27:06 +0300
From:   Vasily Averin <vvs@...tuozzo.com>
To:     linux-kernel@...r.kernel.org, linux-arch@...r.kernel.org,
        Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>, Arnd Bergmann <arnd@...db.de>
Subject: [PATCH] generic arch_futex_atomic_op_inuser() cleanup

Access to 'op' variable does not require pagefault_disable(),
'ret' variable should be initialized before using,
'oldval' variable can be replaced by constant.

Signed-off-by: Vasily Averin <vvs@...tuozzo.com>
---
 include/asm-generic/futex.h | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/include/asm-generic/futex.h b/include/asm-generic/futex.h
index 8666fe7f35d7..e9a9655d786d 100644
--- a/include/asm-generic/futex.h
+++ b/include/asm-generic/futex.h
@@ -118,9 +118,7 @@ futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
 static inline int
 arch_futex_atomic_op_inuser(int op, u32 oparg, int *oval, u32 __user *uaddr)
 {
-	int oldval = 0, ret;
-
-	pagefault_disable();
+	int ret = 0;
 
 	switch (op) {
 	case FUTEX_OP_SET:
@@ -132,10 +130,8 @@ arch_futex_atomic_op_inuser(int op, u32 oparg, int *oval, u32 __user *uaddr)
 		ret = -ENOSYS;
 	}
 
-	pagefault_enable();
-
 	if (!ret)
-		*oval = oldval;
+		*oval = 0;
 
 	return ret;
 }
-- 
2.17.1