From patchwork Wed Oct 7 16:08:08 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: "Gustavo A. R. Silva" X-Patchwork-Id: 11820893 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 0FD4E618 for ; Wed, 7 Oct 2020 16:02:12 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id CDF3221D40 for ; Wed, 7 Oct 2020 16:02:11 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="mmGuJcVP" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CDF3221D40 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id D804B6E94B; Wed, 7 Oct 2020 16:02:10 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by gabe.freedesktop.org (Postfix) with ESMTPS id D223D6E947; Wed, 7 Oct 2020 16:02:08 +0000 (UTC) Received: from embeddedor (187-162-31-110.static.axtel.net [187.162.31.110]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 79BDF216C4; Wed, 7 Oct 2020 16:02:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1602086528; bh=kOWMKdamMcHW4Au2qrv3BhwsErtH4o8/QHcKuDMMRZU=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=mmGuJcVPJl3uga+8gAEvy+A4ZKDXXdQ1NcKMQBBi5AlUWLanqoW8qlXaryD82NEW4 GoHt/F/tvWyIsctqQoCyH9T9Z5JlH4PeAgiNDx3M7SWbmbHIv3udv5fnnIBt2vPFcy KswO3N14vLrZHi7XvcFESAd5CWm3c3Mw3kLOfJ5M= Date: Wed, 7 Oct 2020 11:08:08 -0500 From: "Gustavo A. R. Silva" To: linux-kernel@vger.kernel.org Subject: [PATCH 09/14] drm/amd/pm: Replace one-element array with flexible-array in struct phm_samu_clock_voltage_dependency_table Message-ID: <7aa857a6242477b90da3643678d2798c7037b30f.1602020074.git.gustavoars@kernel.org> References: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.9.4 (2018-02-28) X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: David Airlie , dri-devel@lists.freedesktop.org, "Gustavo A. R. Silva" , amd-gfx@lists.freedesktop.org, linux-hardening@vger.kernel.org, Alex Deucher , Christian =?iso-8859-1?q?K=F6nig?= Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" There is a regular need in the kernel to provide a way to declare having a dynamically sized set of trailing elements in a structure. Kernel code should always use “flexible array members”[1] for these cases. The older style of one-element or zero-length arrays should no longer be used[2]. Refactor the code according to the use of a flexible-array member in struct phm_samu_clock_voltage_dependency_table, instead of a one-element array, and use the struct_size() helper to calculate the size for the allocation. Also, save some heap space as the original code is multiplying table->numEntries by sizeof(struct phm_samu_clock_voltage_dependency_table) when it should have been multiplied it by sizeof(struct phm_samu_clock_voltage_dependency_record) instead. [1] https://en.wikipedia.org/wiki/Flexible_array_member [2] https://www.kernel.org/doc/html/v5.9-rc1/process/deprecated.html#zero-length-and-one-element-arrays Build-tested-by: kernel test robot Link: https://lore.kernel.org/lkml/5f7c5d3a.ryM4GmZr3e0JeZy+%25lkp@intel.com/ Signed-off-by: Gustavo A. R. Silva --- drivers/gpu/drm/amd/pm/inc/hwmgr.h | 2 +- .../gpu/drm/amd/pm/powerplay/hwmgr/processpptables.c | 11 ++++------- 2 files changed, 5 insertions(+), 8 deletions(-) diff --git a/drivers/gpu/drm/amd/pm/inc/hwmgr.h b/drivers/gpu/drm/amd/pm/inc/hwmgr.h index 7e0c948a7097..dad703ba0522 100644 --- a/drivers/gpu/drm/amd/pm/inc/hwmgr.h +++ b/drivers/gpu/drm/amd/pm/inc/hwmgr.h @@ -404,7 +404,7 @@ struct phm_samu_clock_voltage_dependency_record { struct phm_samu_clock_voltage_dependency_table { uint8_t count; - struct phm_samu_clock_voltage_dependency_record entries[1]; + struct phm_samu_clock_voltage_dependency_record entries[]; }; struct phm_cac_tdp_table { diff --git a/drivers/gpu/drm/amd/pm/powerplay/hwmgr/processpptables.c b/drivers/gpu/drm/amd/pm/powerplay/hwmgr/processpptables.c index e059802d1e25..48d550d26c6a 100644 --- a/drivers/gpu/drm/amd/pm/powerplay/hwmgr/processpptables.c +++ b/drivers/gpu/drm/amd/pm/powerplay/hwmgr/processpptables.c @@ -1163,15 +1163,12 @@ static int get_samu_clock_voltage_limit_table(struct pp_hwmgr *hwmgr, struct phm_samu_clock_voltage_dependency_table **ptable, const ATOM_PPLIB_SAMClk_Voltage_Limit_Table *table) { - unsigned long table_size, i; + unsigned long i; struct phm_samu_clock_voltage_dependency_table *samu_table; - table_size = sizeof(unsigned long) + - sizeof(struct phm_samu_clock_voltage_dependency_table) * - table->numEntries; - - samu_table = kzalloc(table_size, GFP_KERNEL); - if (NULL == samu_table) + samu_table = kzalloc(struct_size(samu_table, entries, table->numEntries), + GFP_KERNEL); + if (!samu_table) return -ENOMEM; samu_table->count = table->numEntries;