From nobody Sat Dec 27 20:52:36 2025 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 91E334186F; Fri, 15 Dec 2023 17:54:55 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 68B50C433B7; Fri, 15 Dec 2023 17:54:55 +0000 (UTC) Received: from rostedt by gandalf with local (Exim 4.97) (envelope-from ) id 1rECPZ-00000002wQm-1wks; Fri, 15 Dec 2023 12:55:45 -0500 Message-ID: <20231215175545.246121768@goodmis.org> User-Agent: quilt/0.67 Date: Fri, 15 Dec 2023 12:55:09 -0500 From: Steven Rostedt To: linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org Cc: Masami Hiramatsu , Mark Rutland , Mathieu Desnoyers , Andrew Morton , Tzvetomir Stoyanov , Vincent Donnefort , Kent Overstreet Subject: [PATCH v4 07/15] ring-buffer: Do no swap cpu buffers if order is different References: <20231215175502.106587604@goodmis.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: "Steven Rostedt (Google)" As all the subbuffer order (subbuffer sizes) must be the same throughout the ring buffer, check the order of the buffers that are doing a CPU buffer swap in ring_buffer_swap_cpu() to make sure they are the same. If the are not the same, then fail to do the swap, otherwise the ring buffer will think the CPU buffer has a specific subbuffer size when it does not. Signed-off-by: Steven Rostedt (Google) --- kernel/trace/ring_buffer.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index dd03887a4737..695b64fbc1cb 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -5350,6 +5350,9 @@ int ring_buffer_swap_cpu(struct trace_buffer *buffer_= a, if (cpu_buffer_a->nr_pages !=3D cpu_buffer_b->nr_pages) goto out; =20 + if (buffer_a->subbuf_order !=3D buffer_b->subbuf_order) + goto out; + ret =3D -EAGAIN; =20 if (atomic_read(&buffer_a->record_disabled)) --=20 2.42.0