From patchwork Fri Dec 4 19:37:04 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Arnd Bergmann X-Patchwork-Id: 1411239 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=linux-tegra-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=none dis=none) header.from=kernel.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 4Cnjfv354Zz9sWP for ; Sat, 5 Dec 2020 06:38:15 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727272AbgLDTh7 (ORCPT ); Fri, 4 Dec 2020 14:37:59 -0500 Received: from mail.kernel.org ([198.145.29.99]:60194 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730545AbgLDTh7 (ORCPT ); Fri, 4 Dec 2020 14:37:59 -0500 From: Arnd Bergmann Authentication-Results: mail.kernel.org; dkim=permerror (bad message/signature format) To: Thierry Reding , Jonathan Hunter Cc: Arnd Bergmann , Timo Alho , linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] firmware: tegra: reduce stack usage Date: Fri, 4 Dec 2020 20:37:04 +0100 Message-Id: <20201204193714.3134651-1-arnd@kernel.org> X-Mailer: git-send-email 2.27.0 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-tegra@vger.kernel.org From: Arnd Bergmann Building the bpmp-debugfs driver for Arm results in a warning for stack usage: drivers/firmware/tegra/bpmp-debugfs.c:321:16: error: stack frame size of 1224 bytes in function 'bpmp_debug_store' [-Werror,-Wframe-larger-than=] static ssize_t bpmp_debug_store(struct file *file, const char __user *buf, It should be possible to rearrange the code to not require two separate buffers for the file name, but the easiest workaround is to use dynamic allocation. Fixes: 5e37b9c137ee ("firmware: tegra: Add support for in-band debug") Signed-off-by: Arnd Bergmann --- drivers/firmware/tegra/bpmp-debugfs.c | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-) diff --git a/drivers/firmware/tegra/bpmp-debugfs.c b/drivers/firmware/tegra/bpmp-debugfs.c index 440d99c63638..e1a6b6add180 100644 --- a/drivers/firmware/tegra/bpmp-debugfs.c +++ b/drivers/firmware/tegra/bpmp-debugfs.c @@ -74,28 +74,34 @@ static void seqbuf_seek(struct seqbuf *seqbuf, ssize_t offset) static const char *get_filename(struct tegra_bpmp *bpmp, const struct file *file, char *buf, int size) { - char root_path_buf[512]; + char *root_path_buf; const char *root_path; - const char *filename; + const char *filename = NULL; size_t root_len; + root_path_buf = kzalloc(512, GFP_KERNEL); + if (!root_path_buf) + goto out; + root_path = dentry_path(bpmp->debugfs_mirror, root_path_buf, sizeof(root_path_buf)); if (IS_ERR(root_path)) - return NULL; + goto out; root_len = strlen(root_path); filename = dentry_path(file->f_path.dentry, buf, size); if (IS_ERR(filename)) - return NULL; + goto out; if (strlen(filename) < root_len || strncmp(filename, root_path, root_len)) - return NULL; + goto out; filename += root_len; +out: + kfree(root_path_buf); return filename; }