From nobody Tue Sep 9 21:32:29 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 8C68FC678D4 for ; Wed, 1 Mar 2023 19:58:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229534AbjCAT6y (ORCPT ); Wed, 1 Mar 2023 14:58:54 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36176 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229481AbjCAT6w (ORCPT ); Wed, 1 Mar 2023 14:58:52 -0500 Received: from msg-1.mailo.com (msg-1.mailo.com [213.182.54.11]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 47E671BE1 for ; Wed, 1 Mar 2023 11:58:32 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=mailo.com; s=mailo; t=1677700704; bh=VAuRPN7+KGTNR1+VCFMHhxksGYKTXl+HO2HTsfXfvqM=; h=X-EA-Auth:Date:From:To:Cc:Subject:Message-ID:MIME-Version: Content-Type; b=DY4M36RwwqKcfemZNla36rdJ51NQMusT5P9slKXJawwaQr+C1iFOGLrkeHiUVY0EI SpA/DuBFLGFVTT+EhT7Vin49qSoOeB8D2PbDvpzviRdMRCUN/eio7kEdjLujcuCFa0 NvqtJIOd5YBZPKua03yl38M4klXbNeUwFRiTYiEM= Received: by b221-3.in.mailobj.net [192.168.90.23] with ESMTP via ip-20.mailobj.net [213.182.54.20] Wed, 1 Mar 2023 20:58:24 +0100 (CET) X-EA-Auth: ZT5g9yCX4u6x+3sfSSH/SrdotTfxuHXI4qIJfeKi32aEOhGPEI++CpQ9p+GzxhETdiM3h23ngSjlySbwXad8tifFL2Y7TWJw Date: Thu, 2 Mar 2023 01:28:20 +0530 From: Deepak R Varma To: Alain Volmat , David Airlie , Daniel Vetter , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org Cc: Saurabh Singh Sengar , Praveen Kumar , Deepak R Varma Subject: [PATCH RESEND] drm/sti: Avoid full proxy f_ops for sti debug attributes Message-ID: MIME-Version: 1.0 Content-Disposition: inline Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Using DEFINE_SIMPLE_ATTRIBUTE macro with the debugfs_create_file() function adds the overhead of introducing a proxy file operation functions to wrap the original read/write inside file removal protection functions. This adds significant overhead in terms of introducing and managing the proxy factory file operations structure and function wrapping at runtime. As a replacement, a combination of DEFINE_DEBUGFS_ATTRIBUTE macro paired with debugfs_create_file_unsafe() is suggested to be used instead. The DEFINE_DEBUGFS_ATTRIBUTE utilises debugfs_file_get() and debugfs_file_put() wrappers to protect the original read and write function calls for the debug attributes. There is no need for any runtime proxy file operations to be managed by the debugfs core. Following coccicheck make command helped identify this change: make coccicheck M=3Ddrivers/gpu/drm/i915/ MODE=3Dpatch COCCI=3D./scripts/co= ccinelle/api/debugfs/debugfs_simple_attr.cocci Signed-off-by: Deepak R Varma Acked-by: Alain Volmat --- Note: Change cross compile tested using stm32_defconfig for arm Resending patch for review and feedback. Initially sent on Jan 11 2023 drivers/gpu/drm/sti/sti_drv.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/gpu/drm/sti/sti_drv.c b/drivers/gpu/drm/sti/sti_drv.c index ef6a4e63198f..c9be82043638 100644 --- a/drivers/gpu/drm/sti/sti_drv.c +++ b/drivers/gpu/drm/sti/sti_drv.c @@ -67,8 +67,8 @@ static int sti_drm_fps_set(void *data, u64 val) return 0; } =20 -DEFINE_SIMPLE_ATTRIBUTE(sti_drm_fps_fops, - sti_drm_fps_get, sti_drm_fps_set, "%llu\n"); +DEFINE_DEBUGFS_ATTRIBUTE(sti_drm_fps_fops, + sti_drm_fps_get, sti_drm_fps_set, "%llu\n"); =20 static int sti_drm_fps_dbg_show(struct seq_file *s, void *data) { @@ -97,8 +97,8 @@ static void sti_drm_dbg_init(struct drm_minor *minor) ARRAY_SIZE(sti_drm_dbg_list), minor->debugfs_root, minor); =20 - debugfs_create_file("fps_show", S_IRUGO | S_IWUSR, minor->debugfs_root, - minor->dev, &sti_drm_fps_fops); + debugfs_create_file_unsafe("fps_show", S_IRUGO | S_IWUSR, minor->debugfs_= root, + minor->dev, &sti_drm_fps_fops); =20 DRM_INFO("%s: debugfs installed\n", DRIVER_NAME); } --=20 2.34.1