LKML Archive on
help / color / mirror / Atom feed
From: Christoph Hellwig <>
To: Andrew Morton <>
Cc: Christoph Hellwig <>, Ira Weiny <>,,
Subject: Re: [PATCH 1/2] mm: call flush_dcache_page in memcpy_to_page and memzero_page
Date: Wed, 14 Jul 2021 07:28:41 +0200	[thread overview]
Message-ID: <> (raw)
In-Reply-To: <>

On Tue, Jul 13, 2021 at 06:31:23PM -0700, Andrew Morton wrote:
> On Tue, 13 Jul 2021 07:52:30 +0200 Christoph Hellwig <> wrote:
> > memcpy_to_page and memzero_page can write to arbitrary pages, which could
> > be in the page cache or in high memory, so  call flush_kernel_dcache_pages
> > to flush the dcache.
> I assume this presently is not known to cause any problems, but that
> some problems might be discovered in the future?  In which case,
> should we cc:stable?

This is a problem when using these helpers on dcache challeneged
architectures.  Right now there are just a few users, chances
are no one used the PC floppy drіver, the aha1542 driver for an ISA
SCSI HBA, and a few advanced and optional btrfs and ext4 features
on those platforms yet since the conversion.  So yes, stable would be

  reply	other threads:[~2021-07-14  5:28 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-07-13  5:52 fix " Christoph Hellwig
2021-07-13  5:52 ` [PATCH 1/2] mm: call flush_dcache_page in " Christoph Hellwig
2021-07-14  1:31   ` Andrew Morton
2021-07-14  5:28     ` Christoph Hellwig [this message]
2021-07-14  8:09   ` Ira Weiny
2021-07-13  5:52 ` [PATCH 2/2] mm: use kmap_local_page in memzero_page Christoph Hellwig

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \ \ \ \ \ \ \
    --subject='Re: [PATCH 1/2] mm: call flush_dcache_page in memcpy_to_page and memzero_page' \

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).