Re: [PATCH][CFT] [coredump] don't use __kernel_write() on kmap_local_page()

Al Viro
2022-10-03T23:37:29Z

On Tue, Oct 04, 2022 at 07:58:14AM +0900, J. R. Okajima wrote:
> Al Viro:
> > Argh.... Try this:
> >
> > fix coredump breakage caused by badly tested "[coredump] don't use __kernel_write() on kmap_local_page()"
>
> Thanx, it passed my local test.
>
>
> > * fix for problem that occurs on rather uncommon setups (and hadn't
> > been observed in the wild) sent very late in the cycle.
>
> If the commit was merged in RC versions, I guess someone found the
> problem earlier.

Most likely - the breakage is really not hard to trigger ;-/

Linus, which way would you prefer to handle that? It's
a brown paperbag stuff - the worst I had in quite a while.
Mea maxima culpa ;-/

One variant would be to revert the original patch, put its
(hopefully) fixed variant into -next and let it sit there for
a while. Another is to put this incremental into -next and
merge it into mainline once it gets a sane amount of testing.

Up to you...