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Date:   Thu, 8 Sep 2022 06:49:47 +0800
From:   Herbert Xu <herbert@gondor.apana.org.au>
To:     Eric Dumazet <edumazet@google.com>
Cc:     Leonard Crestez <cdleonard@gmail.com>,
        David Ahern <dsahern@kernel.org>,
        Dmitry Safonov <0x7f454c46@gmail.com>,
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        Philip Paeps <philip@trouble.is>,
        Shuah Khan <shuah@kernel.org>,
        "David S. Miller" <davem@davemloft.net>,
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        Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>,
        Jakub Kicinski <kuba@kernel.org>,
        Yuchung Cheng <ycheng@google.com>,
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Subject: Re: [PATCH v8 08/26] tcp: authopt: Disable via sysctl by default
Message-ID: <YxkgC1XKmCNGzk3t@gondor.apana.org.au>
References: <cover.1662361354.git.cdleonard@gmail.com>
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On Tue, Sep 06, 2022 at 04:11:58PM -0700, Eric Dumazet wrote:
>
> WRITE_ONCE(sysctl_tcp_authopt, val),  or even better:
> 
> if (val)
>      cmpxchg(&sysctl_tcp_authopt, 0, val);

What's the point of the cmpxchg? Since you're simply trying to prevent
sysctl_tcp_authopt from going back to zero, then the if clause
by itself is enough:

	if (val)
		WRITE_ONCE(sysctl_tcp_authopt, val);

Cheers,
-- 
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt