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

[ebiederm@xmission.com (Eric W. Biederman)]

"H. Peter Anvin" <hpa@zytor.com> writes:

> 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;

It is a parameter to the reserve_memtype and free_memtype functions,
which take a u64 so the type looks ok.

If I was going to quibble I would argue that those functions should
take a pfn instead of a u64...

Eric