netdev - Re: [PATCH v2 net-next 1/5] net: Get skb hash over flow

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

Date:	Tue, 12 May 2015 10:30:46 -0400 (EDT)
From:	David Miller <davem@...emloft.net>
To:	eric.dumazet@...il.com
Cc:	tom@...bertland.com, netdev@...r.kernel.org
Subject: Re: [PATCH v2 net-next 1/5] net: Get skb hash over flow_keys
 structure

From: Eric Dumazet <eric.dumazet@...il.com>
Date: Mon, 11 May 2015 21:56:46 -0700

> On Mon, 2015-05-11 at 20:26 -0700, Tom Herbert wrote:
 ...
> This (2) is not a multiple of 4, so some arches will have unaligned word
> accesses ?
 ...
>> -static __always_inline u32 __flow_hash_3words(u32 a, u32 b, u32 c, u32 keyval)
>> +static __always_inline u32 __flow_hash_words(u32 *words, u32 length, u32 keyval)
>>  {
>> -	return jhash_3words(a, b, c, keyval);
>> +	return jhash2(words, length, keyval);
>> +}
>> +
> 
> -> crash or very slow on MIPS.

Yeah you really can't do this.  You must only pass 4-byte aligned items
into the hash function.
--
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