From mboxrd@z Thu Jan 1 00:00:00 1970 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 BC5D315D1; Fri, 14 Feb 2025 00:27:36 +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=1739492856; cv=none; b=FZm5PDBE/GWgkX/7JhwdIOfmU0pbV5pXnhnp/j2LjjVJFE9p46QKRqnveLEQulh6KituZbhJEs9/MQ2wUzg93Ra5Z39s7w3zPxuQypI+akwkM+17r8CVOkdNAL8LC0o6/yeHPTOQmhN3540WOoa3Rkd/nzocTT+9ItmMbaafmT4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739492856; c=relaxed/simple; bh=lzasSBqCZsMzMvKJCwaSsF4RMTN7fMcWPM3EndeXCHQ=; h=Date:From:To:Cc:Subject:Message-Id:In-Reply-To:References: Mime-Version:Content-Type; b=l5LBOIBFcLDJ/cueXjluBxJzgi1Y/OR9dnkoxkbD2s7iO82zY+0zsmH2VjxOV1nMQRw/tBByofgQ+PE8Cpsa09IwB4jiIOOkS/DZ+cZxSEqy/D80EHPUVvs//e+JRhqDRmRjM/Gv7um8Jlwjj40ZgEQk5DukyPHtbxNW+NMgLOE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=qH1XZ621; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="qH1XZ621" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A7D8AC4CED1; Fri, 14 Feb 2025 00:27:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1739492856; bh=lzasSBqCZsMzMvKJCwaSsF4RMTN7fMcWPM3EndeXCHQ=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=qH1XZ621nEUET6F0YY9IRFEI3iH78nnMtXZQUpQCGsVkIsc/O6Q1FTIhOnSL3PkGK Zqi/DWQamtRrio1rqxOmOkXsj3hldbZHHq7ZIukZRuxBErqp3Ffii9bSsBZ84uZwh2 YJT/LLeDvDLH5aK3zsDWAf5ferPja3MY52/hyS2e5K7g/QeQU+FZCQHDly2mJ8XIff fUUfaCuPsVel45udJ0l0yC8Jfl1jNg652tBhTXNGBPdbQ7R2OKJ4Tae8q2jhkI8Oco wFdPmtTtivZ1UymPFgC/i4K1Ft/jRZO2XFSB4yrMu/DtN8D5XAgNmDEOWFXSxHOnla XNDih8tUaYMSQ== Date: Fri, 14 Feb 2025 09:27:32 +0900 From: Masami Hiramatsu (Google) To: Steven Rostedt Cc: LKML , Linux Trace Kernel , Masami Hiramatsu , Mathieu Desnoyers , Vincent Donnefort Subject: Re: [PATCH] tracing: Have the error of __tracing_resize_ring_buffer() passed to user Message-Id: <20250214092732.32e4a05358f2e9a96fecf5d7@kernel.org> In-Reply-To: <20250213134132.7e4505d7@gandalf.local.home> References: <20250213134132.7e4505d7@gandalf.local.home> X-Mailer: Sylpheed 3.8.0beta1 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Thu, 13 Feb 2025 13:41:32 -0500 Steven Rostedt wrote: > From: Steven Rostedt > > Currently if __tracing_resize_ring_buffer() returns an error, the > tracing_resize_ringbuffer() returns -ENOMEM. But it may not be a memory > issue that caused the function to fail. If the ring buffer is memory > mapped, then the resizing of the ring buffer will be disabled. But if the > user tries to resize the buffer, it will get an -ENOMEM returned, which is > confusing because there is plenty of memory. The actual error returned was > -EBUSY, which would make much more sense to the user. > Looks good to me. Reviewed-by: Masami Hiramatsu (Google) Thanks, > Cc: stable@vger.kernel.org > Fixes: 117c39200d9d7 ("ring-buffer: Introducing ring-buffer mapping functions") > Signed-off-by: Steven Rostedt (Google) > --- > kernel/trace/trace.c | 8 +------- > 1 file changed, 1 insertion(+), 7 deletions(-) > > diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c > index 1496a5ac33ae..25ff37aab00f 100644 > --- a/kernel/trace/trace.c > +++ b/kernel/trace/trace.c > @@ -5977,8 +5977,6 @@ static int __tracing_resize_ring_buffer(struct trace_array *tr, > ssize_t tracing_resize_ring_buffer(struct trace_array *tr, > unsigned long size, int cpu_id) > { > - int ret; > - > guard(mutex)(&trace_types_lock); > > if (cpu_id != RING_BUFFER_ALL_CPUS) { > @@ -5987,11 +5985,7 @@ ssize_t tracing_resize_ring_buffer(struct trace_array *tr, > return -EINVAL; > } > > - ret = __tracing_resize_ring_buffer(tr, size, cpu_id); > - if (ret < 0) > - ret = -ENOMEM; > - > - return ret; > + return __tracing_resize_ring_buffer(tr, size, cpu_id); > } > > static void update_last_data(struct trace_array *tr) > -- > 2.47.2 > -- Masami Hiramatsu (Google)