linux-mm.kvack.org archive mirror
 help / color / mirror / Atom feed
From: Dominik Brodowski <linux@dominikbrodowski.net>
To: keescook@chromium.org, andreyknvl@google.com
Cc: linux-hardening@vger.kernel.org, linux-mm@kvack.org,
	tglx@linutronix.de, glider@google.com, vbabka@suse.cz
Subject: regresion v5.13-rc1+ - page_poison broken since 51cba1ebc60d
Date: Tue, 8 Jun 2021 18:50:56 +0200	[thread overview]
Message-ID: <YL+f8LKmLOb4iSeq@light.dominikbrodowski.net> (raw)

Hi Kees, Andrey,

a "git bisect" points to commit 51cba1ebc60d ("init_on_alloc: Optimize
static branches") as breaking page poisoning ("page_poison=on"). Starting
with this commit, booting -- with this option enabled on the kernel command
line -- hangs quite early, before anything meaningful is printed. Booting
51cba1ebc60d without this option proceeds just fine.

Since 1bb5eab30d68 ("kasan, mm: integrate page_alloc init with HW_TAGS") the
behaviour becomes different: Since that commit, booting with
"page_poison=on" and "slub_debug=P" continues up to the initramfs
stage, but then fails quite spectacularly with a large number of page
poisonings being reported.

While "page_poision=on slub_debug=P" doesn't seem to be necessary any longer
if CONFIG_INIT_ON_ALLOC_DEFAULT_ON and CONFIG_INIT_ON_FREE_DEFAULT_ON are
enabled[*], this still looks like a regression.

Thanks,
	Dominik

[*] https://kernsec.org/wiki/index.php/Kernel_Self_Protection_Project/Recommended_Settings


                 reply	other threads:[~2021-06-08 16:52 UTC|newest]

Thread overview: [no followups] expand[flat|nested]  mbox.gz  Atom feed

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=YL+f8LKmLOb4iSeq@light.dominikbrodowski.net \
    --to=linux@dominikbrodowski.net \
    --cc=andreyknvl@google.com \
    --cc=glider@google.com \
    --cc=keescook@chromium.org \
    --cc=linux-hardening@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=tglx@linutronix.de \
    --cc=vbabka@suse.cz \
    /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