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From: James Bottomley <James.Bottomley@SteelEye.com>
To: Andrew Morton <akpm@osdl.org>
Cc: linux-scsi@vger.kernel.org
Subject: Re: ips.c warnings
Date: Sun, 16 Oct 2005 18:11:06 -0500	[thread overview]
Message-ID: <1129504267.9388.4.camel@mulgrave> (raw)
In-Reply-To: <20051016155715.3edda40d.akpm@osdl.org>

On Sun, 2005-10-16 at 15:57 -0700, Andrew Morton wrote:
> James Bottomley <James.Bottomley@SteelEye.com> wrote:
> >  That's weird ... the compiler can't possibly be in a position to make
> >  that judgement call.  We have lots of places where we return null if
> >  something goes wrong and the kernel oopses.  The compiler certainly
> >  isn't warning about all of them.
> 
> Well I guess the difference is that the compiler can _see_ that
> IPS_SG_ADDRESS() might return NULL:
> 
> #define IPS_SG_ADDRESS(sg)      (page_address((sg)->page) ? \
>                                   page_address((sg)->page)+(sg)->offset : NULL)
> 
> What's the point in this expression anyway?  Why not just assume that
> page_address() returns non-NULL?

Actually, what it should be doing is a kmap/kunmap on page instead of
assuming the page has an address ...  hopefully the IPS people can fix
it.

James



  reply	other threads:[~2005-10-16 23:11 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2005-10-16 21:08 ips.c warnings Andrew Morton
2005-10-16 22:44 ` James Bottomley
2005-10-16 22:57   ` Andrew Morton
2005-10-16 23:11     ` James Bottomley [this message]
2005-10-16 23:24       ` Andrew Morton
  -- strict thread matches above, loose matches on Subject: below --
2005-10-20 16:59 Jack Hammer
2005-10-20 17:05 ` Matthew Wilcox
2005-10-20 17:25 Hammer, Jack
2005-10-20 17:29 ` Christoph Hellwig
2005-10-20 17:54   ` James Bottomley
2005-10-20 17:33 IpsLinux
2005-10-20 17:38 Salyzyn, Mark
2005-10-20 17:39 ` Christoph Hellwig
2005-10-20 17:59 IpsLinux

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