From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id AE603C4167B for ; Sun, 10 Dec 2023 04:04:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231582AbjLJEEm (ORCPT ); Sat, 9 Dec 2023 23:04:42 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33242 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229488AbjLJEEI (ORCPT ); Sat, 9 Dec 2023 23:04:08 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A02A211C for ; Sat, 9 Dec 2023 20:04:14 -0800 (PST) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4E44FC433D9; Sun, 10 Dec 2023 04:04:14 +0000 (UTC) Received: from rostedt by gandalf with local (Exim 4.97) (envelope-from ) id 1rCB3j-000000021QH-1SGg; Sat, 09 Dec 2023 23:04:51 -0500 Message-ID: <20231210040451.136611306@goodmis.org> User-Agent: quilt/0.67 Date: Sat, 09 Dec 2023 22:54:14 -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 10/14] tracing: Stop the tracing while changing the ring buffer subbuf size References: <20231210035404.053677508@goodmis.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: "Steven Rostedt (Google)" Because the main buffer and the snapshot buffer need to be the same for some tracers, otherwise it will fail and disable all tracing, the tracers need to be stopped while updating the sub buffer sizes so that the tracers see the main and snapshot buffers with the same sub buffer size. Fixes: TBD ("ring-buffer: Add interface for configuring trace sub buffer size") Signed-off-by: Steven Rostedt (Google) --- kernel/trace/trace.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 7faaaf29b504..9e5f2392d521 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -9397,13 +9397,16 @@ buffer_order_write(struct file *filp, const char __user *ubuf, if (val < 0 || val > 7) return -EINVAL; + /* Do not allow tracing while changing the order of the ring buffer */ + tracing_stop_tr(tr); + old_order = ring_buffer_subbuf_order_get(tr->array_buffer.buffer); if (old_order == val) - return 0; + goto out; ret = ring_buffer_subbuf_order_set(tr->array_buffer.buffer, val); if (ret) - return 0; + goto out; #ifdef CONFIG_TRACER_MAX_TRACE @@ -9430,11 +9433,15 @@ buffer_order_write(struct file *filp, const char __user *ubuf, */ tracing_disabled = 1; } - return ret; + goto out; } out_max: #endif (*ppos)++; + out: + if (ret) + cnt = ret; + tracing_start_tr(tr); return cnt; } -- 2.42.0