LKML Archive on lore.kernel.org
 help / color / Atom feed
From: "Ahmed S. Darwish" <a.darwish@linutronix.de>
To: Varad Gautam <varad.gautam@suse.com>
Cc: linux-kernel@vger.kernel.org,
	linux-rt-users <linux-rt-users@vger.kernel.org>,
	netdev@vger.kernel.org, stable@vger.kernel.org,
	Steffen Klassert <steffen.klassert@secunet.com>,
	Herbert Xu <herbert@gondor.apana.org.au>,
	"David S. Miller" <davem@davemloft.net>,
	Jakub Kicinski <kuba@kernel.org>, Florian Westphal <fw@strlen.de>,
	"Peter Zijlstra (Intel)" <peterz@infradead.org>
Subject: Re: [PATCH v2] xfrm: policy: Read seqcount outside of rcu-read side in xfrm_policy_lookup_bytype
Date: Fri, 28 May 2021 18:44:37 +0200
Message-ID: <YLEd9RS8Cebjv2ho@lx-t490> (raw)
In-Reply-To: <20210528160407.32127-1-varad.gautam@suse.com>

On Fri, May 28, 2021, Varad Gautam wrote:
>
> Thead 1 (xfrm_hash_resize)	Thread 2 (xfrm_policy_lookup_bytype)
>
> 				rcu_read_lock();
> mutex_lock(&hash_resize_mutex);
> 				read_seqcount_begin(&xfrm_policy_hash_generation);
> 				mutex_lock(&hash_resize_mutex); // block
> xfrm_bydst_resize();
> synchronize_rcu(); // block
> 		<RCU stalls in xfrm_policy_lookup_bytype>
>
...
>
> Fixes: 77cc278f7b20 ("xfrm: policy: Use sequence counters with associated lock")
> Signed-off-by: Varad Gautam <varad.gautam@suse.com>

Acked-by: Ahmed S. Darwish <a.darwish@linutronix.de>

  reply index

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-05-28 12:03 [PATCH] " Varad Gautam
2021-05-28 15:11 ` Ahmed S. Darwish
2021-05-28 16:06   ` Varad Gautam
2021-05-28 16:04 ` [PATCH v2] " Varad Gautam
2021-05-28 16:44   ` Ahmed S. Darwish [this message]
2021-06-03  8:16     ` Steffen Klassert

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=YLEd9RS8Cebjv2ho@lx-t490 \
    --to=a.darwish@linutronix.de \
    --cc=davem@davemloft.net \
    --cc=fw@strlen.de \
    --cc=herbert@gondor.apana.org.au \
    --cc=kuba@kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-rt-users@vger.kernel.org \
    --cc=netdev@vger.kernel.org \
    --cc=peterz@infradead.org \
    --cc=stable@vger.kernel.org \
    --cc=steffen.klassert@secunet.com \
    --cc=varad.gautam@suse.com \
    /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

LKML Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lkml.kernel.org/lkml/0 lkml/git/0.git
	git clone --mirror https://lkml.kernel.org/lkml/1 lkml/git/1.git
	git clone --mirror https://lkml.kernel.org/lkml/2 lkml/git/2.git
	git clone --mirror https://lkml.kernel.org/lkml/3 lkml/git/3.git
	git clone --mirror https://lkml.kernel.org/lkml/4 lkml/git/4.git
	git clone --mirror https://lkml.kernel.org/lkml/5 lkml/git/5.git
	git clone --mirror https://lkml.kernel.org/lkml/6 lkml/git/6.git
	git clone --mirror https://lkml.kernel.org/lkml/7 lkml/git/7.git
	git clone --mirror https://lkml.kernel.org/lkml/8 lkml/git/8.git
	git clone --mirror https://lkml.kernel.org/lkml/9 lkml/git/9.git
	git clone --mirror https://lkml.kernel.org/lkml/10 lkml/git/10.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 lkml lkml/ https://lkml.kernel.org/lkml \
		linux-kernel@vger.kernel.org
	public-inbox-index lkml

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-kernel


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git