linux-mm.kvack.org archive mirror
 help / color / mirror / Atom feed
From: Dave Hansen <dave.hansen@linux.intel.com>
To: Alexander Potapenko <glider@google.com>,
	mingo@kernel.org, kirill.shutemov@linux.intel.com
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org,
	mka@chromium.org, dvyukov@google.com, md@google.com
Subject: Re: [PATCH] x86/boot/64/clang: Use fixup_pointer() to access '__supported_pte_mask'
Date: Tue, 8 May 2018 07:30:48 -0700	[thread overview]
Message-ID: <1f69bdb6-df5e-d709-064a-4f6fdd6e11a7@linux.intel.com> (raw)
In-Reply-To: <20180508121638.174022-1-glider@google.com>

On 05/08/2018 05:16 AM, Alexander Potapenko wrote:
> Similarly to commit 187e91fe5e91
> ("x86/boot/64/clang: Use fixup_pointer() to access 'next_early_pgt'"),
> '__supported_pte_mask' must be also accessed using fixup_pointer() to
> avoid position-dependent relocations.
> 
> Signed-off-by: Alexander Potapenko <glider@google.com>
> Fixes: fb43d6cb91ef ("x86/mm: Do not auto-massage page protections")

In the interests of standalone changelogs, I'd really appreciate an
actual explanation of what's going on here.  Your patch makes the code
uglier and doesn't fix anything functional from what I can see.

The other commit has some explanation, so it seems like the rules for
accessing globals in head64.c are different than other files because...
something.

The functional problem here is that it causes insta-reboots?

Do we have anything we can do to keep us from recreating these kinds of
regressions all the time?

  reply	other threads:[~2018-05-08 14:30 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-05-08 12:16 Alexander Potapenko
2018-05-08 14:30 ` Dave Hansen [this message]
2018-05-08 14:50   ` Alexander Potapenko
2018-05-08 16:25     ` Dave Hansen

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:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

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

  git send-email \
    --in-reply-to=1f69bdb6-df5e-d709-064a-4f6fdd6e11a7@linux.intel.com \
    --to=dave.hansen@linux.intel.com \
    --cc=dvyukov@google.com \
    --cc=glider@google.com \
    --cc=kirill.shutemov@linux.intel.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=md@google.com \
    --cc=mingo@kernel.org \
    --cc=mka@chromium.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox