On Thu, Sep 03, 2020 at 05:43:25PM +0200, Christophe Leroy wrote:
>
>
> Le 03/09/2020 à 16:22, Christoph Hellwig a écrit :
>> Stop providing the possibility to override the address space using
>> set_fs() now that there is no need for that any more.
>>
>> Signed-off-by: Christoph Hellwig <hch@xxxxxx>
>> ---
>
>
>> -static inline int __access_ok(unsigned long addr, unsigned long size,
>> - mm_segment_t seg)
>> +static inline bool __access_ok(unsigned long addr, unsigned long size)
>> {
>> - if (addr > seg.seg)
>> - return 0;
>> - return (size == 0 || size - 1 <= seg.seg - addr);
>> + if (addr >= TASK_SIZE_MAX)
>> + return false;
>> + return size == 0 || size <= TASK_SIZE_MAX - addr;
>> }
>
> You don't need to test size == 0 anymore. It used to be necessary because
> of the 'size - 1', as size is unsigned.
>
> Now you can directly do
>
> return size <= TASK_SIZE_MAX - addr;
>
> If size is 0, this will always be true (because you already know that addr
> is not >= TASK_SIZE_MAX
True. What do you think of Linus' comment about always using the
ppc32 version on ppc64 as well with this?
