From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-21.6 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 74A65C433E9 for ; Wed, 10 Feb 2021 23:50:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4D5D964DE3 for ; Wed, 10 Feb 2021 23:50:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234076AbhBJXuV (ORCPT ); Wed, 10 Feb 2021 18:50:21 -0500 Received: from mail.kernel.org ([198.145.29.99]:33470 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233744AbhBJXuK (ORCPT ); Wed, 10 Feb 2021 18:50:10 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 660B764E0B; Wed, 10 Feb 2021 23:49:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1613000970; bh=DFd7DSXy7nWVxMi3ogNh04lyt3UKSNz0wPfFB3/Ikgk=; h=Date:From:To:Cc:Subject:From; b=RwE0EQrcXAXhRu1tEHQ5OhsgYK9JITPA5slwojL1+mXW77Z8/D7tRuDy1HrBeaNDi VSoq6CR/wVeUFMyFlVpogSpN78LwdeH5XGoLpMSHKSsAS39OBexHYcGz7nUI3cSElf pEhdAKrevf4lPyeCXeXC2xLVhsNo2ROTK8vxd6WVAJwem1bv+G36GDRLwJXdn7jQCA 6HG7oiRQ/xiXWpnelxJgLOzGhYUy0qDiZUPImb86cg+e57sZh1Z4tfOz3bTKymv2N8 Fq6+9zJNjKrznJWXV08nvgsPXEnSBZPFkS58LWHyMzO9Br/s54B6maQz3ZGArCPUPb vCxAkBdkPgidQ== Date: Wed, 10 Feb 2021 17:49:27 -0600 From: "Gustavo A. R. Silva" To: Alex Deucher , Christian =?iso-8859-1?Q?K=F6nig?= , David Airlie , Daniel Vetter Cc: amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" , linux-hardening@vger.kernel.org Subject: [PATCH][next] drm/radeon/nislands_smc.h: Replace one-element array with flexible-array member in struct NISLANDS_SMC_SWSTATE Message-ID: <20210210234927.GA68137@embeddedor> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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]. Use flexible-array member in struct NISLANDS_SMC_SWSTATE, instead of one-element array. Also, this helps with the ongoing efforts to enable -Warray-bounds by fixing the following warnings: drivers/gpu/drm/radeon/ni_dpm.c: In function ‘ni_convert_power_state_to_smc’: drivers/gpu/drm/radeon/ni_dpm.c:2521:20: warning: array subscript 1 is above array bounds of ‘NISLANDS_SMC_HW_PERFORMANCE_LEVEL[1]’ {aka ‘struct NISLANDS_SMC_HW_PERFORMANCE_LEVEL[1]’} [-Warray-bounds] 2521 | smc_state->levels[i].dpm2.MaxPS = | ~~~~~~~~~~~~~~~~~^~~ drivers/gpu/drm/radeon/ni_dpm.c:2523:20: warning: array subscript 1 is above array bounds of ‘NISLANDS_SMC_HW_PERFORMANCE_LEVEL[1]’ {aka ‘struct NISLANDS_SMC_HW_PERFORMANCE_LEVEL[1]’} [-Warray-bounds] 2523 | smc_state->levels[i].dpm2.NearTDPDec = NISLANDS_DPM2_NEAR_TDP_DEC; | ~~~~~~~~~~~~~~~~~^~~ drivers/gpu/drm/radeon/ni_dpm.c:2524:20: warning: array subscript 1 is above array bounds of ‘NISLANDS_SMC_HW_PERFORMANCE_LEVEL[1]’ {aka ‘struct NISLANDS_SMC_HW_PERFORMANCE_LEVEL[1]’} [-Warray-bounds] 2524 | smc_state->levels[i].dpm2.AboveSafeInc = NISLANDS_DPM2_ABOVE_SAFE_INC; | ~~~~~~~~~~~~~~~~~^~~ drivers/gpu/drm/radeon/ni_dpm.c:2525:20: warning: array subscript 1 is above array bounds of ‘NISLANDS_SMC_HW_PERFORMANCE_LEVEL[1]’ {aka ‘struct NISLANDS_SMC_HW_PERFORMANCE_LEVEL[1]’} [-Warray-bounds] 2525 | smc_state->levels[i].dpm2.BelowSafeInc = NISLANDS_DPM2_BELOW_SAFE_INC; | ~~~~~~~~~~~~~~~~~^~~ drivers/gpu/drm/radeon/ni_dpm.c:2526:35: warning: array subscript 1 is above array bounds of ‘NISLANDS_SMC_HW_PERFORMANCE_LEVEL[1]’ {aka ‘struct NISLANDS_SMC_HW_PERFORMANCE_LEVEL[1]’} [-Warray-bounds] 2526 | smc_state->levels[i].stateFlags |= | ^~ drivers/gpu/drm/radeon/ni_dpm.c:2526:35: warning: array subscript 1 is above array bounds of ‘NISLANDS_SMC_HW_PERFORMANCE_LEVEL[1]’ {aka ‘struct NISLANDS_SMC_HW_PERFORMANCE_LEVEL[1]’} [-Warray-bounds] 2526 | smc_state->levels[i].stateFlags |= | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~ 2527 | ((i != (state->performance_level_count - 1)) && power_boost_limit) ? | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 2528 | PPSMC_STATEFLAG_POWERBOOST : 0; | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ drivers/gpu/drm/radeon/ni_dpm.c:2442:20: warning: array subscript 1 is above array bounds of ‘NISLANDS_SMC_HW_PERFORMANCE_LEVEL[1]’ {aka ‘struct NISLANDS_SMC_HW_PERFORMANCE_LEVEL[1]’} [-Warray-bounds] 2442 | smc_state->levels[i + 1].aT = cpu_to_be32(a_t); [1] https://en.wikipedia.org/wiki/Flexible_array_member [2] https://www.kernel.org/doc/html/v5.9/process/deprecated.html#zero-length-and-one-element-arrays Link: https://github.com/KSPP/linux/issues/79 Link: https://github.com/KSPP/linux/issues/109 Build-tested-by: kernel test robot Link: https://lore.kernel.org/lkml/6023ed54.BfIY+9Uz81I6nq19%25lkp@intel.com/ Signed-off-by: Gustavo A. R. Silva --- drivers/gpu/drm/radeon/nislands_smc.h | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/drivers/gpu/drm/radeon/nislands_smc.h b/drivers/gpu/drm/radeon/nislands_smc.h index 3cf8fc0d83f4..7395cb6b3cac 100644 --- a/drivers/gpu/drm/radeon/nislands_smc.h +++ b/drivers/gpu/drm/radeon/nislands_smc.h @@ -134,11 +134,11 @@ typedef struct NISLANDS_SMC_HW_PERFORMANCE_LEVEL NISLANDS_SMC_HW_PERFORMANCE_LEV struct NISLANDS_SMC_SWSTATE { - uint8_t flags; - uint8_t levelCount; - uint8_t padding2; - uint8_t padding3; - NISLANDS_SMC_HW_PERFORMANCE_LEVEL levels[1]; + uint8_t flags; + uint8_t levelCount; + uint8_t padding2; + uint8_t padding3; + NISLANDS_SMC_HW_PERFORMANCE_LEVEL levels[]; }; typedef struct NISLANDS_SMC_SWSTATE NISLANDS_SMC_SWSTATE; -- 2.27.0