Re: [PATCH] uio: fix is_source param for check_copy_size() in copy_to_iter_mcsafe()

[Dan Williams]

On Wed, Sep 12, 2018 at 2:57 PM, Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
> On Wed, Sep 12, 2018 at 02:51:53PM -0700, Dan Williams wrote:
>> On Wed, Sep 12, 2018 at 12:48 AM, Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
>> > On Wed, Sep 05, 2018 at 01:31:40PM -0700, Dave Jiang wrote:
>> >> copy_to_iter_mcsafe() is passing in the is_source parameter as "false"
>> >> to check_copy_size(). This is different than what copy_to_iter() does.
>> >> Also, the addr parameter passed to check_copy_size() is the source so
>> >> therefore we should be passing in "true" instead.
>> >>
>> >> Fixes: 8780356ef630 ("x86/asm/memcpy_mcsafe: Define copy_to_iter_mcsafe()")
>> >> Cc: Fan Du <fan.du@xxxxxxxxx>
>> >> Reported-by: Wenwei Tao <wenwei.tww@xxxxxxxxxxxxxxx>
>> >> Signed-off-by: Dave Jiang <dave.jiang@xxxxxxxxx>
>> >> Reviewed-by: Vishal Verma <vishal.l.verma@xxxxxxxxx>
>> >> Cc: stable <stable@xxxxxxxxxxxxxxx>
>> >> ---
>> >>  include/linux/uio.h |    2 +-
>> >
>> > I am not the maintainer of this file, sorry, please work with the -mm
>> > developers for this.
>>
>> Likely this is get_maintainer.pl's fault:
>>
>> $ ./scripts/get_maintainer.pl  -f include/linux/uio.h
>> Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> (maintainer:USERSPACE I/O (UIO))
>> linux-kernel@xxxxxxxxxxxxxxx (open list)
>>
>> Maybe a MAINTAINERS update like the following is warranted, because I
>> don't think -mm developers are right either, Al seems to be authority
>> on iov_iter apis:
>>
>> diff --git a/MAINTAINERS b/MAINTAINERS
>> index d870cb57c887..0018e19b4d8e 100644
>> --- a/MAINTAINERS
>> +++ b/MAINTAINERS
>> @@ -15344,13 +15344,18 @@ F:    arch/x86/um/
>>  F:     fs/hostfs/
>>  F:     fs/hppfs/
>>
>> +USERSPACE ACCESS (uaccess, copy_{to,from}_iter)
>> +M:     Alexander Viro <viro@xxxxxxxxxxxxxxxxxx>
>> +S:     Maintained
>> +F:     include/linux/uio*.h
>> +F:     lib/iov_iter.c
>> +
>>  USERSPACE I/O (UIO)
>>  M:     Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
>>  S:     Maintained
>>  T:     git git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git
>>  F:     Documentation/driver-api/uio-howto.rst
>>  F:     drivers/uio/
>> -F:     include/linux/uio*.h
>
> Don't drop that line, uio_driver.h is what it should just say, right?
>

Ah, yep, I missed that. Thanks.