From: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
To: Puranjay Mohan <puranjay@kernel.org>
Cc: "Paul E . McKenney" <paulmck@kernel.org>,
linux-kernel@vger.kernel.org, Boqun Feng <boqun@kernel.org>,
Josh Triplett <josh@joshtriplett.org>,
Frederic Weisbecker <frederic@kernel.org>,
Neeraj Upadhyay <neeraj.upadhyay@kernel.org>,
Joel Fernandes <joelagnelf@nvidia.com>,
Uladzislau Rezki <urezki@gmail.com>,
Steven Rostedt <rostedt@goodmis.org>,
Lai Jiangshan <jiangshanlai@gmail.com>,
Zqiang <qiang.zhang@linux.dev>,
Linus Torvalds <torvalds@linux-foundation.org>,
Matthew Wilcox <willy@infradead.org>,
Christian Brauner <brauner@kernel.org>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
"Liam R . Howlett" <liam@infradead.org>,
Lorenzo Stoakes <ljs@kernel.org>,
Alice Ryhl <aliceryhl@google.com>,
Andrew Ballance <andrewjballance@gmail.com>,
Peter Zijlstra <peterz@infradead.org>,
Will Deacon <will@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
Ingo Molnar <mingo@kernel.org>, Thomas Gleixner <tglx@kernel.org>,
rcu@vger.kernel.org
Subject: Re: [RFC PATCH 09/12] rcu_txn: Test a list writer against concurrent readers
Date: Tue, 10 Nov 2026 10:13:43 -0500 [thread overview]
Message-ID: <5282f0a7-6df3-46c1-a668-9fc0a1c57aec@efficios.com> (raw)
In-Reply-To: <20261023182218.479327-6-puranjay@kernel.org>
On 2026-10-23 14:22, Puranjay Mohan wrote:
[...]
> prev_key already skips the first step, so I'd count
> back == &head->node as a violation.
Agreed. Counting it is planned for the next version.
[...]
> If the writer oopses, KUnit fails the test and frees c and the readers
> array while these threads are still walking the list. Registering the
> stop with kunit_add_action_or_reset(), and calling
> kunit_release_action() where they're stopped now, would avoid the
> use-after-free.
Planned for the next version, as you describe.
[...]
> A failed conc_del() here leaks the node without anyone noticing. The
> readers are already stopped at this point, so the leftovers could just
> be kfree()d.
In the next version, a delete will no longer fail. The test will unlink
and free the leftovers directly, without a grace period.
Thanks,
Mathieu
--
Mathieu Desnoyers
EfficiOS Inc.
https://www.efficios.com
next prev parent reply other threads:[~2026-11-10 15:13 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-10-16 13:33 [RFC PATCH 00/12] RCU pseudo-transactions Mathieu Desnoyers
2026-10-16 13:33 ` [RFC PATCH 01/12] rcu_txn: Add single-writer " Mathieu Desnoyers
2026-10-23 18:22 ` Puranjay Mohan
2026-11-10 15:11 ` Mathieu Desnoyers
2026-10-16 13:33 ` [RFC PATCH 02/12] rcu_txn: Add KUnit tests Mathieu Desnoyers
2026-10-16 13:33 ` [RFC PATCH 03/12] rcu_txn: Skip the record lookup with a Bloom filter Mathieu Desnoyers
2026-10-23 18:22 ` Puranjay Mohan
2026-11-10 15:12 ` Mathieu Desnoyers
2026-10-16 13:33 ` [RFC PATCH 04/12] rcu_txn: Add CONFIG_DEBUG_RCU_TXN Mathieu Desnoyers
2026-10-23 18:22 ` Puranjay Mohan
2026-11-10 15:12 ` Mathieu Desnoyers
2026-10-16 13:33 ` [RFC PATCH 05/12] rcu_txn: Add an hlist edited through transactions Mathieu Desnoyers
2026-10-23 18:22 ` Puranjay Mohan
2026-11-10 15:12 ` Mathieu Desnoyers
2026-10-16 13:33 ` [RFC PATCH 06/12] rcu_txn: Add a doubly-linked list coherent in both directions Mathieu Desnoyers
2026-10-23 18:22 ` Puranjay Mohan
2026-11-10 15:13 ` Mathieu Desnoyers
2026-10-16 13:33 ` [RFC PATCH 07/12] Documentation/RCU: Describe RCU pseudo-transactions Mathieu Desnoyers
2026-10-16 13:33 ` [RFC PATCH 08/12] Documentation/litmus-tests: Add RCU pseudo-transaction tests Mathieu Desnoyers
2026-10-16 13:33 ` [RFC PATCH 09/12] rcu_txn: Test a list writer against concurrent readers Mathieu Desnoyers
2026-10-23 18:22 ` Puranjay Mohan
2026-11-10 15:13 ` Mathieu Desnoyers [this message]
2026-10-16 13:33 ` [RFC PATCH 10/12] rcu_txn: Test a commit from atomic context Mathieu Desnoyers
2026-10-23 18:22 ` Puranjay Mohan
2026-11-10 15:14 ` Mathieu Desnoyers
2026-10-16 13:33 ` [RFC PATCH 11/12] samples: Add a cache on RCU pseudo-transactions under one mutex Mathieu Desnoyers
2026-10-16 13:33 ` [RFC PATCH 12/12] samples: Add a cache on RCU pseudo-transactions with a lock per node Mathieu Desnoyers
2026-10-23 18:22 ` Puranjay Mohan
2026-11-10 15:14 ` Mathieu Desnoyers
2026-10-19 0:55 ` [RFC PATCH 00/12] RCU pseudo-transactions Joel Fernandes
2026-10-23 13:37 ` Mathieu Desnoyers
2026-10-23 18:19 ` Puranjay Mohan
2026-10-27 19:57 ` Mathieu Desnoyers
2026-10-28 1:13 ` Mathieu Desnoyers
2026-11-10 0:25 ` Paul E. McKenney
2026-11-10 1:00 ` Mathieu Desnoyers
2026-11-10 1:34 ` Paul E. McKenney
2026-11-10 15:26 ` Mathieu Desnoyers
2026-11-10 15:11 ` Mathieu Desnoyers
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=5282f0a7-6df3-46c1-a668-9fc0a1c57aec@efficios.com \
--to=mathieu.desnoyers@efficios.com \
--cc=aliceryhl@google.com \
--cc=andrewjballance@gmail.com \
--cc=boqun@kernel.org \
--cc=brauner@kernel.org \
--cc=frederic@kernel.org \
--cc=gregkh@linuxfoundation.org \
--cc=jiangshanlai@gmail.com \
--cc=joelagnelf@nvidia.com \
--cc=josh@joshtriplett.org \
--cc=liam@infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=ljs@kernel.org \
--cc=mark.rutland@arm.com \
--cc=mingo@kernel.org \
--cc=neeraj.upadhyay@kernel.org \
--cc=paulmck@kernel.org \
--cc=peterz@infradead.org \
--cc=puranjay@kernel.org \
--cc=qiang.zhang@linux.dev \
--cc=rcu@vger.kernel.org \
--cc=rostedt@goodmis.org \
--cc=tglx@kernel.org \
--cc=torvalds@linux-foundation.org \
--cc=urezki@gmail.com \
--cc=will@kernel.org \
--cc=willy@infradead.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
all inboxes | Powered by JetHome®