Re: Linux 2.6.26-rc4

[Arjan van de Ven <arjan@infradead.org>]

On Mon, 26 May 2008 17:25:19 -0700
Arjan van de Ven <arjan@infradead.org> wrote:

> On Mon, 26 May 2008 14:42:37 -0700 (PDT)
> Linus Torvalds <torvalds@linux-foundation.org> wrote:
> 
> > 
> > 
> > On Mon, 26 May 2008, Jesper Krogh wrote:
> > > 
> > > I did get this one (which I didn't on 2.6.25.2)
> > > 
> > > [42949399.810959] ck804xrom ck804xrom_init_one(): Unable to
> > > register resource 0x0000000000000000-0x00000000ffffffff - kernel
> > > bug?
> > 
> > Something is trying to register a 4GB resource. That sounds
> > unlikely (possible on a 64-bit PCI setup, but I think it's more
> > likely to be some overflow of 0 in "unsigned int").
> > 
> > In fact, this seems to be due to some driver bug. It looks like we
> > have
> > 
> > 	window->size = 0xffffffffUL - window->phys + 1UL;
> > 
> > and in order for window->size to be 0x100000000, that means that 
> > window->phys has to be 0. Which looks impossible, or at least like 
> > ent->driver_data is neither DEV_CK804 nor DEV_MCP55. Very odd.
> > 
> > The warning:
> > 
> > > [42949399.979924] WARNING: at arch/x86/mm/ioremap.c:159
> > > __ioremap_caller+0x299/0x330()
> > 
> > is then just a result of the driver blindly continuing and trying
> > to "ioremap()" the resource even though it's bogus and the resource 
> > allocation failed.
> > 
> > In other words, that driver init routine is really bad about error 
> > handling. Carl-Daniel? David?
> > 
> 
> btw this guy has shown up on kerneloops.org a lot: 
> http://www.kerneloops.org/searchweek.php?search=__ioremap_caller
> where it's trying to map memory as uncachable, which is.. well nasty
> (it seems to map not just the piece it needs, but more, and then turns
> that "more" uncachable, even if the kernel is using it for "normal"
> things)

one thing to note: it only shows up on 64 bit kernels somehow...
interesting.



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