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

[Greg KH]

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?

thanks,

greg k-h