Re: [PATCH] i386 pci: Handle mmaping 64bit bars.

From: H. Peter Anvin
Date: Sat Feb 14 2009 - 01:17:54 EST


Eric W. Biederman wrote:
> While reading through pci_mmap_page_range I realized that if don't
> properly handle 64bit bars in the 32bit kernel.
>
> Without the added cast the shift will be done in 32bit despite being
> assigned to a 64bit variable and if we are mmaping an address above
> 4G things will do the wrong thing.

Hm... this really should be resource_size_t, no?

> - u64 addr = vma->vm_pgoff << PAGE_SHIFT;
> + u64 addr = ((u64)vma->vm_pgoff) << PAGE_SHIFT;

-hpa

--
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel. I don't speak on their behalf.

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