Re: [PATCH v2] powerpc: support sizes greater than an unsigned long

From: Cristian Stoica
Date: Fri Jun 12 2015 - 04:08:39 EST


On 06/12/2015 12:27 AM, Scott Wood wrote:
> Dropping the upper bits of the size harms the ability to detect error
> scenarios where unmappably large -- but not power-of-two -- regions
> are requested to be mapped.
>
> However, this patch doesn't fix that. It just postpones the loss of
> the upper 32 bits until __ioremap_caller() calls get_vm_area_caller().
>
> There's also no error checking at all for the size of ioremap() done
> during early boot (!slab_is_available()).

Thanks for the explanation. I'll have a another look at the code.

> Don't just blindly turn static analyzer reports into patches -- and
> why didn't the analyzer complain about the call to
> get_vm_area_caller() after this patch?

The analysis that lead to this patch was targeted to a specific driver - in hindsight this is probably not the best
approach.

Cristian S.
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