From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B0FA52F7EF5; Tue, 25 Aug 2026 17:44:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787679893; cv=none; b=ZvImlPeC7SybexUZ4W0caGJ//F8OrQ5V9aaiKZJLJS6CtJGlSHnubUPjKmBsQNK0Ka9D16XYEF2sKIucOnZQBFwR2EKxp0xGnv7xtdydOYSXDUG+3JGDzfUsxtBzL7wzEooPoch67ezxed6EzLhMgJ8rw0AlvrrDvdvk3BN8u+0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787679893; c=relaxed/simple; bh=IvWFykD79hZlQAf9Yz33kNHckU0lf7DJHusgEUFmvI4=; h=Date:To:From:Subject:Message-Id; b=Cbxrj1yy0QnPlX2fKj7Tnca1kg5rt93GMQcGzsRJDvq9eCQA4Awpn5mJ53LxP7JvkF2b1AcZbfZuu8WRIv/ZmAGjOpCOQUgbMXKLl5o19HdzHssa6ZSNVsWCgVZERCmY08O8f58H4r3QCYjDTjNC791c6B3b1MKNf6umH53wz78= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=KtXVxjWJ; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="KtXVxjWJ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5EDE61F000E9; Tue, 25 Aug 2026 17:44:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=korg; t=1787679891; bh=uFyJO5DeWFx0FRxNd0kZ245YNDEH+Lh6CCL2arLJneE=; h=Date:To:From:Subject; b=KtXVxjWJXF0027Zk2GiBmK0RV49U+VN7gsp0S9l+bpjf1TRpIL7c1D2PSuVl0IpaL dXoA9Q02Pv0265Dq4Yqr14PraYF9Gd+sSRjxH01Lgtr1AyutztdTUXkQAU0uM7Px21 0HuFxdRLFMwzCwUrp0puzyevMP4cxS0CIfWdkdrs= Date: Tue, 25 Aug 2026 10:44:50 -0700 To: mm-commits@vger.kernel.org,tony.luck@intel.com,stable@vger.kernel.org,shinichiro.kawasaki@wdc.com,reinette.chatre@intel.com,nilay@linux.ibm.com,kbusch@kernel.org,edumazet@google.com,akpm@linux-foundation.org From: Andrew Morton Subject: + revert-once-dont-use-a-work-queue-to-reset-sleepable-static-key.patch added to mm-hotfixes-unstable branch Message-Id: <20260825174451.5EDE61F000E9@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The patch titled Subject: Revert "once: don't use a work queue to reset sleepable static key" has been added to the -mm mm-hotfixes-unstable branch. Its filename is revert-once-dont-use-a-work-queue-to-reset-sleepable-static-key.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/revert-once-dont-use-a-work-queue-to-reset-sleepable-static-key.patch This patch will later appear in the mm-hotfixes-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via various branches at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there most days ------------------------------------------------------ From: Eric Dumazet Subject: Revert "once: don't use a work queue to reset sleepable static key" Date: Tue, 25 Aug 2026 14:25:15 +0000 This reverts commit e8eef69a99f185e75909adb24ab93d706e07bf27. While DO_ONCE_SLEEPABLE() is used from sleepable/process context, callers may still be holding arbitrary subsystem locks. For instance, __inet_hash_connect() uses get_random_sleepable_once() which invokes DO_ONCE_SLEEPABLE() while holding the socket lock (sk_lock): lock_sock(sk) __inet_hash_connect() get_random_sleepable_once() DO_ONCE_SLEEPABLE() __do_once_sleepable_done() static_branch_disable() static_key_disable() cpus_read_lock() Calling static_branch_disable() directly from __do_once_sleepable_done() causes static_key_disable() to synchronously acquire cpus_read_lock() (cpu_hotplug_lock) and jump_label_mutex inside the caller's lock context. This introduces an unwanted lockdep dependency: sk_lock -> cpu_hotplug_lock Because cpu_hotplug_lock depends on fs_reclaim (via workqueue CPU bringup allocating memory with GFP_KERNEL), and storage/block layers (such as NVMe-TCP) acquire sk_lock during I/O dispatch, lockdep reports circular locking dependencies: set->srcu -> sk_lock -> cpu_hotplug_lock -> fs_reclaim -> q_usage_counter -> elevator_lock -> set->srcu This false positive previously prompted commit 19bdb70c77d3 ("nvme-tcp: lockdep: use dynamic lockdep keys per socket instance") to work around the warning using per-socket dynamic keys in NVMe-TCP. That in turn broke asynchronous socket teardown and caused syzbot warnings in tcp_tsq_handler(). Restoring once_disable_jump() in __do_once_sleepable_done() ensures that static_branch_disable() is executed asynchronously from a system workqueue without holding the caller's locks. Link: https://lore.kernel.org/20260825142515.1965654-1-edumazet@google.com Fixes: e8eef69a99f1 ("once: don't use a work queue to reset sleepable static key") Signed-off-by: Eric Dumazet Closes: https://lore.kernel.org/lkml/ao0mwtt8ePAINFni@shinhome/ Reported-by: Shin'ichiro Kawasaki Cc: Tony Luck Cc: Reinette Chatre Cc: Keith Busch Cc: Nilay Shroff Cc: Signed-off-by: Andrew Morton --- lib/once.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/lib/once.c~revert-once-dont-use-a-work-queue-to-reset-sleepable-static-key +++ a/lib/once.c @@ -93,6 +93,6 @@ void __do_once_sleepable_done(bool *done { *done = true; mutex_unlock(&once_mutex); - static_branch_disable(once_key); + once_disable_jump(once_key, mod); } EXPORT_SYMBOL(__do_once_sleepable_done); _ Patches currently in -mm which might be from edumazet@google.com are mm-mempolicy-fix-sleeping-allocation-in-alloc_pages_bulk_weighted_interleave.patch revert-once-dont-use-a-work-queue-to-reset-sleepable-static-key.patch