From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mout02.posteo.de (mout02.posteo.de [185.67.36.66]) (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 4655E443D for ; Mon, 31 Oct 2022 20:53:19 +0000 (UTC) Received: from submission (posteo.de [185.67.36.169]) by mout02.posteo.de (Postfix) with ESMTPS id A6C8F240104 for ; Mon, 31 Oct 2022 21:47:02 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=posteo.eu; s=2017; t=1667249222; bh=14ImJoriqviYQaubYTW2HWYoZcV6WuztfnCI0NZQ2Bc=; h=Date:From:Subject:To:Cc:From; b=gej8Gn2LSjg738qmxy8uVtlwf9JsIbOnvnfrCwfjY+h5gegHfJyfxWrd15e7Jkk1f QBbOwJW1v4MvyEVdu6T31zOI9Phhexk5056aP0lDnsQtHzxzmtVxzaHkxuSsAzQi7X fH9y6aSM0B7ilKPyXA/Vm9gVXgkbhMa8UrX1CDAlNMPYmXdDs0jBLqXVJQ//Ai8nTY APMTRjk7szb7F8SNb1UZHZSHp5+uK+WPm87U8yN5H/6w7DFXmmY3+ejuAYV7puizJ/ 8ohSH/N1Q4p0V6iHe4cIjk5KW9TdNPLrJSbMqzHbVNoMBY2CpCaZxX93HS9KbnRy7F 4MBVgvUgFAujg== Received: from customer (localhost [127.0.0.1]) by submission (posteo.de) with ESMTPSA id 4N1QF20DLqz9rxB; Mon, 31 Oct 2022 21:47:02 +0100 (CET) Message-ID: <71829e56-a13f-0462-37a7-a4d64c16f561@posteo.de> Date: Mon, 31 Oct 2022 20:47:01 +0000 Precedence: bulk X-Mailing-List: regressions@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: postix@posteo.eu Subject: Fwd: [REGRESSION 6.0.x / 6.1.x] NULL dereferencing at tracing Reply-To: 20221031144850.5522b036@rorschach.local.home To: rostedt@goodmis.org Cc: linux-kernel@vger.kernel.org, regressions@lists.linux.dev, tiwai@suse.de References: Content-Language: en-US, de-DE In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit > Can you apply this to see if it fixes it? > > I'm guessing there's a path to the release of the file descriptor where > the ring buffer isn't allocated (and this expected it to be). > > I'll investigate further to see if I can find that path. > > -- Steve > > diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c > index 199759c73519..c1c7ce4c6ddb 100644 --- > a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ > -937,6 +937,9 @@ void ring_buffer_wake_waiters(struct trace_buffer > *buffer, int cpu) struct ring_buffer_per_cpu *cpu_buffer; > struct rb_irq_work *rbwork; > > + if (!buffer) + return; + if (cpu == RING_BUFFER_ALL_CPUS) { > > /* Wake up individual ones too. One level recursion */ Dear Steve, I have tested your suggested patch using kernel 6.1.0-rc2, but unfortunately it didn't fix the issue for me. Thank you for looking into it though! Best Regards --AD