On Mon, 27 Jan 2025 at 17:21, Al Viro <viro@xxxxxxxxxxxxxxxxxx> wrote:
>
> Umm... On some architectures it does, but mostly that's the ones
> where unaligned word loads are costly. Which target do you have
> in mind?
I was more thinking that we could just make the fallback case be a 'memcmp()'.
It's not like this particular place matters - as you say, that
byte-at-a-time code is only used on architectures that don't enable
the dcache word-at-a-time code (that requires the special "do loads
that can fault" zeropad helper), but we've had some other places where
we'd worry about the string length.
Look at d_path() for another example. That copy_from_kernel_nofault()
in prepend_copy()...
Linus
