[PATCH] inet: set `error' value not under lock_sock().

[PATCH] inet: set `error' value not under lock_sock().

[Weongyo Jeong]

A trivial patch to set `error' variable while not holding
lock_sock().

Signed-off-by: Weongyo Jeong <weongyo.linux@gmail.com>
---
 net/ipv4/inet_connection_sock.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c
index 6414891..58bc39f 100644
--- a/net/ipv4/inet_connection_sock.c
+++ b/net/ipv4/inet_connection_sock.c
@@ -306,14 +306,13 @@ struct sock *inet_csk_accept(struct sock *sk, int flags, int *err)
 	struct request_sock_queue *queue = &icsk->icsk_accept_queue;
 	struct request_sock *req;
 	struct sock *newsk;
-	int error;
+	int error = -EINVAL;
 
 	lock_sock(sk);
 
 	/* We need to make sure that this socket is listening,
 	 * and that it has something pending.
 	 */
-	error = -EINVAL;
 	if (sk->sk_state != TCP_LISTEN)
 		goto out_err;
 
-- 
2.1.3

Re: [PATCH] inet: set `error' value not under lock_sock().

[David Miller]

From: Weongyo Jeong <weongyo.linux@gmail.com>
Date: Wed, 9 Mar 2016 10:22:21 -0800

> A trivial patch to set `error' variable while not holding
> lock_sock().
> 
> Signed-off-by: Weongyo Jeong <weongyo.linux@gmail.com>

Deferring the assignment means gcc doesn't have to potentially put it
on the stack across the lock_sock() call.

You're making the code worse not better, the assignment into a local
variable is not an expensive operation.

I'm not applying this change, sorry.

Re: [PATCH] inet: set `error' value not under lock_sock().

[Weongyo Jeong]

On 03/09/2016 12:37 PM, David Miller wrote:
> From: Weongyo Jeong <weongyo.linux@gmail.com>
> Date: Wed, 9 Mar 2016 10:22:21 -0800
>
>> A trivial patch to set `error' variable while not holding
>> lock_sock().
>>
>> Signed-off-by: Weongyo Jeong <weongyo.linux@gmail.com>
>
> Deferring the assignment means gcc doesn't have to potentially put it
> on the stack across the lock_sock() call.
>
> You're making the code worse not better, the assignment into a local
> variable is not an expensive operation.
>
> I'm not applying this change, sorry.

No problem.  Thank you for review and opinion.

Regards,
Weongyo Jeong



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