From nobody Tue Dec 16 16:39:03 2025 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 E3724C4332F for ; Wed, 13 Dec 2023 15:41:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1442401AbjLMPla (ORCPT ); Wed, 13 Dec 2023 10:41:30 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37826 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1442177AbjLMPl3 (ORCPT ); Wed, 13 Dec 2023 10:41:29 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7226BBD for ; Wed, 13 Dec 2023 07:41:35 -0800 (PST) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7B580C433C8; Wed, 13 Dec 2023 15:41:34 +0000 (UTC) Date: Wed, 13 Dec 2023 10:42:18 -0500 From: Steven Rostedt To: LKML , Linux Trace Kernel Cc: Masami Hiramatsu , Mark Rutland , Mathieu Desnoyers Subject: [PATCH v2] tracing: Increase size of trace_marker_raw to max ring buffer entry Message-ID: <20231213104218.2efc70c1@gandalf.local.home> X-Mailer: Claws Mail 3.19.1 (GTK+ 2.24.33; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: "Steven Rostedt (Google)" There's no reason to give an arbitrary limit to the size of a raw trace marker. Just let it be as big as the size that is allowed by the ring buffer itself. And there's also no reason to artificially break up the write to TRACE_BUF_SIZE, as that's not even used. Reviewed-by: Masami Hiramatsu (Google) Signed-off-by: Steven Rostedt (Google) --- Changes since v1: https://lore.kernel.org/linux-trace-kernel/20231209175716= .09ac455b@gandalf.local.home - Moved "if (size > ring_buffer_max_event_size(buffer))" to after "buffer" is assigned, otherwise it creates an uninitialized warning error. (kernel test robot) kernel/trace/trace.c | 14 +++++--------- 1 file changed, 5 insertions(+), 9 deletions(-) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index e07baf388ab3..95d02804d3ae 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -7359,9 +7359,6 @@ tracing_mark_write(struct file *filp, const char __us= er *ubuf, return written; } =20 -/* Limit it for now to 3K (including tag) */ -#define RAW_DATA_MAX_SIZE (1024*3) - static ssize_t tracing_mark_raw_write(struct file *filp, const char __user *ubuf, size_t cnt, loff_t *fpos) @@ -7383,19 +7380,18 @@ tracing_mark_raw_write(struct file *filp, const cha= r __user *ubuf, return -EINVAL; =20 /* The marker must at least have a tag id */ - if (cnt < sizeof(unsigned int) || cnt > RAW_DATA_MAX_SIZE) + if (cnt < sizeof(unsigned int)) return -EINVAL; =20 - if (cnt > TRACE_BUF_SIZE) - cnt =3D TRACE_BUF_SIZE; - - BUILD_BUG_ON(TRACE_BUF_SIZE >=3D PAGE_SIZE); - size =3D sizeof(*entry) + cnt; if (cnt < FAULT_SIZE_ID) size +=3D FAULT_SIZE_ID - cnt; =20 buffer =3D tr->array_buffer.buffer; + + if (size > ring_buffer_max_event_size(buffer)) + return -EINVAL; + event =3D __trace_buffer_lock_reserve(buffer, TRACE_RAW_DATA, size, tracing_gen_ctx()); if (!event) --=20 2.42.0