Re: [PATCH] ttm: Fix a potential comparison of structs.

[Pekka Paalanen <pq@iki.fi>]

On Sun, 02 Aug 2009 20:12:18 +0200
Thomas Hellström <thellstrom@vmware.com> wrote:

> Pekka Paalanen skrev:
> > From 5e2851952729b287a82efa002b28a2095404d44d Mon Sep 17 00:00:00 2001
> > From: Thomas Hellstrom <thellstrom@vmware.com>
> > Date: Fri, 31 Jul 2009 10:47:51 +0200
> > Subject: [PATCH] ttm: Fix a potential comparison of structs.
> >
> > On some architectures the comparison may cause a compilation failure.
> >
> > Original partial fix Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
> >
> > Signed-off-by: Pekka Paalanen <pq@iki.fi>
> > ---
> >
> > Thomas, you forgot two more of these :-)
> > Here's a patch that actually compiles on x86_64.
> >   
> 
> Pekka,
> Thanks for fixing this! (Just for clarity, i assume you mean that the 
> non-x86 part now compiles on x86?)

Ah yes, that's what I mean. I changed the #ifdefs for my compat fix in
http://cgit.freedesktop.org/nouveau/linux-2.6/log/?h=master-compat
and tried compiling it the both ways.

> Dave, is there a chance to have this in 2.6.31? Compilation errors are 
> bad, although probably nobody has been hitting this yet..

Well, Nouveau master-compat users would have hit it, but I added your
fix, too. Users with x86_32 highmem kernels already hit the
kmap_atomic_prot not exported bug while building the latest DRM,
TTM and Nouveau bits against distro kernels.

So yeah, no-one anyone (else) would care about ;-)


Thanks.

> 
> /Thomas
> 
> >  drivers/gpu/drm/ttm/ttm_bo_util.c |    8 ++++----
> >  1 files changed, 4 insertions(+), 4 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/ttm/ttm_bo_util.c b/drivers/gpu/drm/ttm/ttm_bo_util.c
> > index f4e2eba..999fbe7 100644
> > --- a/drivers/gpu/drm/ttm/ttm_bo_util.c
> > +++ b/drivers/gpu/drm/ttm/ttm_bo_util.c
> > @@ -151,7 +151,7 @@ static int ttm_copy_io_ttm_page(struct ttm_tt *ttm, void *src,
> >  #ifdef CONFIG_X86
> >  	dst = kmap_atomic_prot(d, KM_USER0, prot);
> >  #else
> > -	if (prot != PAGE_KERNEL)
> > +	if (pgprot_val(prot) != pgprot_val(PAGE_KERNEL))
> >  		dst = vmap(&d, 1, 0, prot);
> >  	else
> >  		dst = kmap(d);
> > @@ -164,7 +164,7 @@ static int ttm_copy_io_ttm_page(struct ttm_tt *ttm, void *src,
> >  #ifdef CONFIG_X86
> >  	kunmap_atomic(dst, KM_USER0);
> >  #else
> > -	if (prot != PAGE_KERNEL)
> > +	if (pgprot_val(prot) != pgprot_val(PAGE_KERNEL))
> >  		vunmap(dst);
> >  	else
> >  		kunmap(d);
> > @@ -187,7 +187,7 @@ static int ttm_copy_ttm_io_page(struct ttm_tt *ttm, void *dst,
> >  #ifdef CONFIG_X86
> >  	src = kmap_atomic_prot(s, KM_USER0, prot);
> >  #else
> > -	if (prot != PAGE_KERNEL)
> > +	if (pgprot_val(prot) != pgprot_val(PAGE_KERNEL))
> >  		src = vmap(&s, 1, 0, prot);
> >  	else
> >  		src = kmap(s);
> > @@ -200,7 +200,7 @@ static int ttm_copy_ttm_io_page(struct ttm_tt *ttm, void *dst,
> >  #ifdef CONFIG_X86
> >  	kunmap_atomic(src, KM_USER0);
> >  #else
> > -	if (prot != PAGE_KERNEL)
> > +	if (pgprot_val(prot) != pgprot_val(PAGE_KERNEL))
> >  		vunmap(src);
> >  	else
> >  		kunmap(s);

-- 
Pekka Paalanen
http://www.iki.fi/pq/