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From:   Thomas Gleixner <tglx@linutronix.de>
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To:     Al Viro <viro@zeniv.linux.org.uk>,
        gus Gusenleitner Klaus <gus@keba.com>
Cc:     lkml <linux-kernel@vger.kernel.org>,
        Ingo Molnar <mingo@redhat.com>, "bp@alien8.de" <bp@alien8.de>,
        "dave.hansen@linux.intel.com" <dave.hansen@linux.intel.com>,
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        "David S. Miller" <davem@davemloft.net>,
        "dsahern@kernel.org" <dsahern@kernel.org>,
        "edumazet@google.com" <edumazet@google.com>,
        "kuba@kernel.org" <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>
Subject: Re: [PATCH] amd64: Fix csum_partial_copy_generic()
In-Reply-To: <20231018154205.GT800259@ZenIV>
References: <VI1PR0702MB3840EB26EF2A1A35BFEA53BFD9D5A@VI1PR0702MB3840.eurprd07.prod.outlook.com>
 <20231018154205.GT800259@ZenIV>
Date:   Wed, 18 Oct 2023 19:37:37 +0200
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On Wed, Oct 18 2023 at 16:42, Al Viro wrote:

> On Wed, Oct 18, 2023 at 06:18:05AM +0000, gus Gusenleitner Klaus wrote:
>> The checksum calculation is wrong in case of an source buffer
>> containing zero bytes only. The expected return value is 0, the
>> actual return value is 0xfffffff.
>
> Expected where?  The actual checksum is defined modulo 0xffff, so
> 0 and 0xffffffff represent the same final value.

Duh. I really should have read the RFC first :)