Re: [PATCH v2 2/3] powerpc/memcpy: Add memcpy_mcsafe for pmem

Balbir Singh
2018-04-05T12:24:09Z

On Thu, Apr 5, 2018 at 9:26 PM, Oliver <oohall@gmail.com> wrote:
> On Thu, Apr 5, 2018 at 5:14 PM, Balbir Singh <bsingharora@gmail.com> wrote:
>> The pmem infrastructure uses memcpy_mcsafe in the pmem
>> layer so as to convert machine check excpetions into
>> a return value on failure in case a machine check
>> exception is encoutered during the memcpy.
>>
>
> Would it be possible to move the bulk of the copyuser code into a
> seperate file which can be #included once the these err macros are
> defined? Anton's memcpy is pretty hairy and I don't think anyone wants
> to have multiple copies of it in the tree, even in a cut down form.
>

I've split it out for now, in the future that might be a good thing to do.
The copy_tofrom_user_power7 falls backs on __copy_tofrom_user_base
to track exactly how much is left over. Adding these changes there would
create a larger churn and need way more testing. I've taken this short-cut
for now with a promise to fix that as the semantics of memcpy_mcsafe()
change to do more accurate tracking of how much was copied over.

Balbir Singh.