Re: [RFC][CFT][PATCHSET v1] uaccess unification

Al Viro
2017-03-30T14:49:17Z

On Thu, Mar 30, 2017 at 02:32:12PM +0200, Martin Schwidefsky wrote:
> On Wed, 29 Mar 2017 06:57:06 +0100
> Al Viro <viro@ZenIV.linux.org.uk> wrote:
>
> > The patchset currently in vfs.git#work.uaccess is the result;
> > there's more work to do, but it takes care of a large part of the
> > problems. About 2.8KLoc removed, a lot of cruft is gone and semantics
> > is hopefully in sync now. All but two architectures (ia64 and metag)
> > had been switched to new mechanism; for these two I'm afraid that I'll
> > need serious help from maintainers.
>
> I have tested the code in vfs.git#work.uaccess and in principle it works
> for s390. I found one bug which would return an incorrect result
> for copy_from_user if the access faults on the last page of the copy.
> In that case the new code would return 0 instead of the remaining bytes.
>
> This patch snippet should fix it, please just merge it into commit
> "s390: get rid of zeroing, switch to RAW_COPY_USER"

Done.