[dpdk-dev] [PATCH] vfio: fix BAR offset type for 32-bit app

Burakov, Anatoly anatoly.burakov at intel.com
Fri Oct 25 17:41:07 CEST 2019


On 24-Oct-19 1:10 PM, Michal Krawczyk wrote:
> When 32-bit application is built on 64-bit system it is possible that
> the offset of the resource is outside of the 32-bit value.
> 
> The problem with the unsigned long is, that it is 32-bit and not 64-bit
> when using armhf compiler. Although the system is returning u64 value,
> we are losing it's value if it's higher than 32-bit in the conversion
> process. It can further cause mmap to fail due to offset being 0 or to
> map not intended memory region.
> 
> To make it more portable, the uint64_t value is now being used for
> storing offset instead of unsigned long. The size of being 32-bit seems
> to be fine as the 32-bit application won't be able to access bigger
> memory and it is further converted to size_t anyway. But for better
> readability and to be consistent, it's type was changed to size_t as
> well.
> 
> Fixes: 0205f873557c ("vfio: fix overflow of BAR region offset and size")
> Cc: rahul.lakkireddy at chelsio.com
> Cc: stable at dpdk.org
> 
> Signed-off-by: Michal Krawczyk <mk at semihalf.com>
> ---

Acked-by: Anatoly Burakov <anatoly.burakov at intel.com>

-- 
Thanks,
Anatoly


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