From: Marco Elver <elver@google.com>
To: Charan Teja Kalla <quic_charante@quicinc.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Alexander Potapenko <glider@google.com>,
Dmitry Vyukov <dvyukov@google.com>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
Dave Hansen <dave.hansen@linux.intel.com>,
x86@kernel.org, "H. Peter Anvin" <hpa@zytor.com>,
kasan-dev@googlegroups.com, linux-kernel@vger.kernel.org,
linux-mm@kvack.org,
syzbot+93a9e8a3dea8d6085e12@syzkaller.appspotmail.com
Subject: Re: [PATCH] mm, kmsan: fix infinite recursion due to RCU critical section
Date: Thu, 18 Jan 2024 13:22:37 +0100 [thread overview]
Message-ID: <CANpmjNNZ6vV7DJ+SBGcSnV6qzkmH_J=WrofrfaAeidvSG2nHbQ@mail.gmail.com> (raw)
In-Reply-To: <cd742d1d-70a3-586b-4bf5-fcfc94c75b4a@quicinc.com>
On Thu, 18 Jan 2024 at 12:28, Charan Teja Kalla
<quic_charante@quicinc.com> wrote:
>
> May I ask if KMSAN also instruments the access to the memory managed as
> ZONE_DEVICE. You know this is not the RAM and also these pages will
> never be onlined thus also not be available in buddy.
>
> Reason for the ask is that this patch is introduced because of a race
> between pfn walker ends up in pfn of zone device memory.
>
> If KMSAN never instruments this, does it look good to you to have the
> KMSAN version of pfn_valid(), as being suggested by Alexander in the
> other mail.
It would be nice to avoid duplicating functions - both options have downsides:
1. Shared pfn_valid(): it might break for KMSAN again in future if new
recursion is introduced.
2. KMSAN-version of pfn_valid(): it might break if pfn_valid() changes
in future.
I suspect #1 is less likely.
What is your main concern by switching to rcu_read_lock_sched()?
next prev parent reply other threads:[~2024-01-18 12:23 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-01-18 10:59 Marco Elver
2024-01-18 11:07 ` Marco Elver
2024-01-18 11:27 ` Charan Teja Kalla
2024-01-18 12:22 ` Marco Elver [this message]
2024-01-19 17:00 ` Charan Teja Kalla
2024-01-18 12:46 ` Alexander Potapenko
2024-01-22 9:56 ` Alexander Potapenko
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='CANpmjNNZ6vV7DJ+SBGcSnV6qzkmH_J=WrofrfaAeidvSG2nHbQ@mail.gmail.com' \
--to=elver@google.com \
--cc=akpm@linux-foundation.org \
--cc=bp@alien8.de \
--cc=dave.hansen@linux.intel.com \
--cc=dvyukov@google.com \
--cc=glider@google.com \
--cc=hpa@zytor.com \
--cc=kasan-dev@googlegroups.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mingo@redhat.com \
--cc=quic_charante@quicinc.com \
--cc=syzbot+93a9e8a3dea8d6085e12@syzkaller.appspotmail.com \
--cc=tglx@linutronix.de \
--cc=x86@kernel.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