netdev - [PATCH] xfrm: avoid spinlock in get

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: Windows password security audit tool. GUI, reports in PDF.

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

Message-ID: <1264773952.3184.22.camel@edumazet-laptop>
Date:	Fri, 29 Jan 2010 15:05:52 +0100
From:	Eric Dumazet <eric.dumazet@...il.com>
To:	David Miller <davem@...emloft.net>
Cc:	netdev <netdev@...r.kernel.org>
Subject: [PATCH] xfrm: avoid spinlock in get_acqseq()

Use atomic_inc_return() in get_acqseq() to avoid taking a spinlock

Signed-off-by: Eric Dumazet <eric.dumazet@...il.com>
---

diff --git a/net/key/af_key.c b/net/key/af_key.c
index 4744b1f..e2aacf0 100644
--- a/net/key/af_key.c
+++ b/net/key/af_key.c
@@ -3019,12 +3019,11 @@ static int pfkey_send_policy_notify(struct xfrm_policy *xp, int dir, struct km_e
 static u32 get_acqseq(void)
 {
 	u32 res;
-	static u32 acqseq;
-	static DEFINE_SPINLOCK(acqseq_lock);
+	static atomic_t acqseq;
 
-	spin_lock_bh(&acqseq_lock);
-	res = (++acqseq ? : ++acqseq);
-	spin_unlock_bh(&acqseq_lock);
+	do {
+		res = atomic_inc_return(&acqseq);
+	} while (!res);
 	return res;
 }
 


--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html