From patchwork Fri Oct 11 20:52:24 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Steven Rostedt X-Patchwork-Id: 13833175 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 5B077199231; Fri, 11 Oct 2024 20:52:15 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728679935; cv=none; b=hJHK1BcT6QruKTTzMpe1anXl7aJ5PQDf1McaEnKwA+BkhQ1L6yWpVIOr2PM9xD6N/kbZ4N5znSZ18OHUpgschka33IZH+IgZIJuvW9klISirMJ+m7K2+mC6dSz+n96fAfO1FqPA5kyj2SXCl8bGZyPTySYGYb9Hzgi6NpGny+SM= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728679935; c=relaxed/simple; bh=/mEtVoE39iP2Qc58gy8XZrokqEhMtz0bKnzSQsjF+j4=; h=Date:From:To:Cc:Subject:Message-ID:MIME-Version:Content-Type; b=kWXPXVQcgFt59vP4kDKAQje3ELE++i1CE2S1vkqWjljjG/GSf2rqstsqapHuZAmZhjgA4Zq3ZKsOxO52H5qGHA/nLBRyYE1d+qtuRSxgZ7WTPmJhbfmxgbFmIdKDLcT/PdkZYKb4A8JM972XVIqZNyPVr++9WQkBnM9XfIekE5s= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4C89AC4CEC3; Fri, 11 Oct 2024 20:52:14 +0000 (UTC) Date: Fri, 11 Oct 2024 16:52:24 -0400 From: Steven Rostedt To: LKML , Linux Trace Kernel Cc: Masami Hiramatsu , Mathieu Desnoyers Subject: [PATCH] ring-buffer: Fix refcount setting of boot mapped buffers Message-ID: <20241011165224.33dd2624@gandalf.local.home> X-Mailer: Claws Mail 3.20.0git84 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: Steven Rostedt A ring buffer which has its buffered mapped at boot up to fixed memory should not be freed. Other buffers can be. The ref counting setup was wrong for both. It made the not mapped buffers ref count have zero, and the boot mapped buffer a ref count of 1. But an normally allocated buffer should be 1, where it can be removed. Keep the ref count of a normal boot buffer with its setup ref count (do not decrement it), and increment the fixed memory boot mapped buffer's ref count. Fixes: e645535a954ad ("tracing: Add option to use memmapped memory for trace boot instance") Signed-off-by: Steven Rostedt (Google) Reviewed-by: Masami Hiramatsu (Google) --- kernel/trace/trace.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index c01375adc471..5ba40f39c8b5 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -10610,10 +10610,10 @@ __init static void enable_instances(void) * cannot be deleted by user space, so keep the reference * to it. */ - if (start) + if (start) { tr->flags |= TRACE_ARRAY_FL_BOOT; - else - trace_array_put(tr); + tr->ref++; + } while ((tok = strsep(&curr_str, ","))) { early_enable_events(tr, tok, true);