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From: Pierre Ossman <drzeus@drzeus.cx>
To: David Miller <davem@davemloft.net>
Cc: netdev@vger.kernel.org
Subject: Re: net: alignment problem in icmp code
Date: Sun, 21 Oct 2007 23:21:13 +0200	[thread overview]
Message-ID: <20071021232113.52ce1be7@poseidon.drzeus.cx> (raw)
In-Reply-To: <20071021.124814.50617600.davem@davemloft.net>

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On Sun, 21 Oct 2007 12:48:14 -0700 (PDT)
David Miller <davem@davemloft.net> wrote:

> 
> You are missing a crucial point.
> 
> The compiler may emit the same exact loads and stores when it inlines
> memcpy() if it "knows" the objects are aligned properly.  And it very
> much will do this.
> 

Not sure that would be valid. memcpy() is defined as having void* arguments, and the compiler cannot just ignore that if it chooses to inline it.

Still, just give it the char* from the skb and it cannot make any assumption on alignment.

Rgds
Pierre

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  reply	other threads:[~2007-10-21 21:21 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-10-20 21:35 net: alignment problem in icmp code Pierre Ossman
2007-10-21  5:12 ` David Miller
2007-10-21  9:34   ` Pierre Ossman
2007-10-21 19:48     ` David Miller
2007-10-21 21:21       ` Pierre Ossman [this message]
2007-10-21 23:02         ` David Miller
2007-10-22  4:54           ` Pierre Ossman
2007-10-22  5:15             ` David Miller
2007-10-22  7:23               ` Pierre Ossman
2007-10-22  8:31                 ` David Miller
2007-10-22  8:42                   ` Pierre Ossman
2007-10-22  9:05                     ` David Miller
2007-10-22  9:26                       ` Pierre Ossman
2007-10-22  9:52                         ` Eric Dumazet

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