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

From: Sedat Dilek <sedat.dilek@gmail.com>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>,
	"J. R. Okajima" <hooanon05g@gmail.com>,
	Ira Weiny <ira.weiny@intel.com>,
	linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org,
	Geert Uytterhoeven <geert@linux-m68k.org>,
	Ren Zhijie <renzhijie2@huawei.com>
Subject: Re: [PATCH][CFT] [coredump] don't use __kernel_write() on kmap_local_page()
Date: Sun, 9 Oct 2022 12:37:54 +0200	[thread overview]
Message-ID: <CA+icZUVBFo3v6L8Y4HNMR3XxsBb9YoMw9j+ehXpkWov9EeM59A@mail.gmail.com> (raw)
In-Reply-To: <CA+icZUVXvMM-sK41oz_Ne4HyRGxXHNz=fPqy+1AYXmXPiE_=Rw@mail.gmail.com>

On Tue, Oct 4, 2022 at 8:18 AM Sedat Dilek <sedat.dilek@gmail.com> wrote:
>
> On Tue, Oct 4, 2022 at 2:51 AM Linus Torvalds
> <torvalds@linux-foundation.org> wrote:
> >
> > On Mon, Oct 3, 2022 at 4:37 PM Al Viro <viro@zeniv.linux.org.uk> wrote:
> > >
> > > 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.
> >
> > Just do the incremental fix. It looks obvious enough ("oops, we need
> > to get the pos _after_ we've done any skip-lseeks on the core file")
> > that I think it would be just harder to follow a "revert and follow up
> > with a fix".
> >
> > I don't think it needs a ton of extra testing, with Okajima having
> > already confirmed it fixes his problem case..
> >
> >                 Linus
>
> [ CC Geert ]
>
> There was another patch from Geert concerning the same coredump changes:
>
> [PATCH] coredump: Move dump_emit_page() to kill unused warning
>
> If CONFIG_ELF_CORE is not set:
>
>     fs/coredump.c:835:12: error: ‘dump_emit_page’ defined but not used
> [-Werror=unused-function]
>       835 | static int dump_emit_page(struct coredump_params *cprm,
> struct page *page)
>           |            ^~~~~~~~~~~~~~
>
> Fix this by moving dump_emit_page() inside the existing section
> protected by #ifdef CONFIG_ELF_CORE.
>
> Fixes: 06bbaa6dc53cb720 ("[coredump] don't use __kernel_write() on
> kmap_local_page()")
> Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
>
> Please, check yourself!
>
> Best regards,
> -Sedat-
>
> [1] https://lore.kernel.org/all/20221003090657.2053236-1-geert@linux-m68k.org/

[ CC Ren Zhijie <renzhijie2@huawei.com> ]

Looks like the same patch as of Geert.

-Sedat-

[1] https://lore.kernel.org/all/20221009092420.32850-1-renzhijie2@huawei.com/