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 6A09C4AB3BE for ; Wed, 16 Sep 2026 15:41:45 +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=1789573307; cv=none; b=etpfTj4D3rBwgFiVb/Bsz9Euen9h3VL8cDQQykgPyD4XjfmaDiP6Rgu71pI/HFubkMayaQNnZrLRTQVk6MPJn4iAWTmqVXzHkbdsoNgorZ+EwRjt/4hNm2nBJdupZhMTTqBHrUCrsBh0+CekedMVCYHKfa7Umap4ESvb5NE3zLk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789573307; c=relaxed/simple; bh=KOW98bL8CgMpChtD+TOHN4YeqxkkezWSmkWtTKZWpe8=; h=Subject:To:Cc:From:Date:Message-ID:MIME-Version:Content-Type; b=F6v8yiSht1fxuE22lrJMneE8GTD4WdxEgtp0atpGNwG7SCwuhM+hwD9ijO8u4/vkSb/ssnMZIQi8uRBr32VtBOLaRBCAyiwHr/6gCzdIxgPz6Jgs/LwCl2bhJwDlKOXMQShN42BnR4WE1YGsyUEz2uS9WKqkJgbqPzbqqjTlDOc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=1CJcAZrt; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="1CJcAZrt" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2474A1F000FF; Wed, 16 Sep 2026 15:41:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789573303; bh=ouH+meodaeP61gPlOmDuSu1eeBvqJhfkNhNpKjTQneE=; h=Subject:To:Cc:From:Date; b=1CJcAZrtWZL30cGhLjssBBeUmHGUWklM9DH4rNlbuKQmow9pJ4oGF9uGv0TwPaPR7 8CxOOk9eHEWcYg9Bx8J4GkBpo7zi8ZYLKRV6RtJ/q4GBYfhsuRWshqXTEE/E4vs21k JCWsC4J7j4vayx1sg/pAsYP9akh2KapoXMOI2rMQ= Subject: FAILED: patch "[PATCH] ring-buffer: Acquire the lock with irqsave in" failed to apply to 5.10-stable tree To: bigeasy@linutronix.de,rostedt@goodmis.org,vdonnefort@google.com Cc: From: Date: Wed, 16 Sep 2026 16:37:41 +0100 Message-ID: <2026091641-backlash-shrank-66b6@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit The patch below does not apply to the 5.10-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.10.y git checkout FETCH_HEAD git cherry-pick -x 815e07c8fe885a87751c2496a30ae0dcd4118210 # git commit -s git send-email --to '' --in-reply-to '2026091641-backlash-shrank-66b6@gregkh' --subject-prefix 'PATCH 5.10.y' 'HEAD^..' Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 815e07c8fe885a87751c2496a30ae0dcd4118210 Mon Sep 17 00:00:00 2001 From: Sebastian Andrzej Siewior Date: Fri, 11 Sep 2026 12:21:52 +0200 Subject: [PATCH] ring-buffer: Acquire the lock with irqsave in rb_wake_up_waiters() rb_wake_up_waiters() is a irq_work callback which is initialized with init_irq_work(). As such it will be invoked in thread context on PREEMPT_RT. Invoking the callback in IRQ context on PREEMPT_RT is not an option due its usage of wake_up_all(). Since this callback may run in thread context, it needs to acquire ring_buffer_per_cpu::reader_lock with disabling interrupts and may not assume that they are disabled. Use raw_spinlock_irqsave() to acquire ring_buffer_per_cpu::reader_lock. Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260911102152.YEtwkBj9@linutronix.de Fixes: 68282dd930ea3 ("ring-buffer: Fix resetting of shortest_full") Reviewed-by: Vincent Donnefort Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Steven Rostedt diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 0e30c7bd6045..9bc8ce8c5676 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -904,14 +904,13 @@ static void rb_wake_up_waiters(struct irq_work *work) struct ring_buffer_per_cpu *cpu_buffer = container_of(rbwork, struct ring_buffer_per_cpu, irq_work); - /* Called from interrupt context */ - raw_spin_lock(&cpu_buffer->reader_lock); - rbwork->wakeup_full = false; - rbwork->full_waiters_pending = false; + scoped_guard(raw_spinlock_irqsave, &cpu_buffer->reader_lock) { + rbwork->wakeup_full = false; + rbwork->full_waiters_pending = false; - /* Waking up all waiters, they will reset the shortest full */ - cpu_buffer->shortest_full = 0; - raw_spin_unlock(&cpu_buffer->reader_lock); + /* Waking up all waiters, they will reset the shortest full */ + cpu_buffer->shortest_full = 0; + } wake_up_all(&rbwork->full_waiters); }