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=-13.1 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 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 392B8C35E04 for ; Tue, 25 Feb 2020 15:28:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EA90421744 for ; Tue, 25 Feb 2020 15:28:25 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=embeddedor.com header.i=@embeddedor.com header.b="K2TmY80n" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731110AbgBYP2Z (ORCPT ); Tue, 25 Feb 2020 10:28:25 -0500 Received: from gateway33.websitewelcome.com ([192.185.146.210]:25518 "EHLO gateway33.websitewelcome.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730987AbgBYP2W (ORCPT ); Tue, 25 Feb 2020 10:28:22 -0500 Received: from cm13.websitewelcome.com (cm13.websitewelcome.com [100.42.49.6]) by gateway33.websitewelcome.com (Postfix) with ESMTP id 8787D4190D2 for ; Tue, 25 Feb 2020 08:01:10 -0600 (CST) Received: from gator4166.hostgator.com ([108.167.133.22]) by cmsmtp with SMTP id 6alqjwAniRP4z6alqjLAgb; Tue, 25 Feb 2020 08:01:10 -0600 X-Authority-Reason: nr=8 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=embeddedor.com; s=default; h=Content-Type:MIME-Version:Message-ID:Subject: Cc:To:From:Date:Sender:Reply-To:Content-Transfer-Encoding:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:In-Reply-To:References:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=RUoiJPKbXOORUMcByfg3y59aLbGOyCajhNRZHKwxYdM=; b=K2TmY80nKM6JNCRMaqOjv6Y2II XFqNYwg3sy7pV8Klv6Z2CYpDDYYf3KFpYCENAtHow/6zmfi1f5q6y9f2zAkS9jI/oYF4JoAq+wcST AJvHG3FrQ7FB4RDL0KCggXRvfAB9mLOHtLxM4N9XJxuGDQXCDr09AhZkPVaQ9WHITZXV0N+oC/5vX i4tsYSH5RXHtjYhQ+ymmn1vXlNxuQXTnaGZlVoSlMissVsAOwJ5GiFCvfz9gDgQb3M4rd1vkhzFdL wjuWLRYQKT5yXwh7t7fk5QpAOoAYW2enhrqXF1i/udxOwjZOK/vU2qCxp0TyiL/cLLfqcR1NIu8T8 5HxBx97Q==; Received: from [201.162.241.105] (port=19602 helo=embeddedor) by gator4166.hostgator.com with esmtpa (Exim 4.92) (envelope-from ) id 1j6alo-001QK9-7P; Tue, 25 Feb 2020 08:01:08 -0600 Date: Tue, 25 Feb 2020 08:03:47 -0600 From: "Gustavo A. R. Silva" To: Lucas Stach , Russell King , Christian Gmeiner , David Airlie , Daniel Vetter , Patrik Jakobsson , Jani Nikula , Joonas Lahtinen , Rodrigo Vivi , Rob Clark , Sean Paul , Dave Airlie , Gerd Hoffmann , Hans de Goede , Eric Anholt , VMware Graphics , Thomas Hellstrom , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann Cc: etnaviv@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, intel-gfx@lists.freedesktop.org, linux-arm-msm@vger.kernel.org, freedreno@lists.freedesktop.org, virtualization@lists.linux-foundation.org, spice-devel@lists.freedesktop.org, "Gustavo A. R. Silva" Subject: [PATCH][next] drm: Replace zero-length array with flexible-array member Message-ID: <20200225140347.GA22864@embeddedor> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.9.4 (2018-02-28) X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - gator4166.hostgator.com X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - embeddedor.com X-BWhitelist: no X-Source-IP: 201.162.241.105 X-Source-L: No X-Exim-ID: 1j6alo-001QK9-7P X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: (embeddedor) [201.162.241.105]:19602 X-Source-Auth: gustavo@embeddedor.com X-Email-Count: 23 X-Source-Cap: Z3V6aWRpbmU7Z3V6aWRpbmU7Z2F0b3I0MTY2Lmhvc3RnYXRvci5jb20= X-Local-Domain: yes Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The current codebase makes use of the zero-length array language extension to the C90 standard, but the preferred mechanism to declare variable-length types such as these ones is a flexible array member[1][2], introduced in C99: struct foo { int stuff; struct boo array[]; }; By making use of the mechanism above, we will get a compiler warning in case the flexible array does not occur last in the structure, which will help us prevent some kind of undefined behavior bugs from being inadvertently introduced[3] to the codebase from now on. Also, notice that, dynamic memory allocations won't be affected by this change: "Flexible array members have incomplete type, and so the sizeof operator may not be applied. As a quirk of the original implementation of zero-length arrays, sizeof evaluates to zero."[1] This issue was found with the help of Coccinelle. [1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html [2] https://github.com/KSPP/linux/issues/21 [3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour") Signed-off-by: Gustavo A. R. Silva --- drivers/gpu/drm/etnaviv/etnaviv_gem.h | 2 +- drivers/gpu/drm/gma500/intel_bios.h | 2 +- drivers/gpu/drm/i915/display/intel_vbt_defs.h | 4 ++-- drivers/gpu/drm/i915/gt/intel_lrc.c | 2 +- drivers/gpu/drm/i915/i915_gpu_error.h | 2 +- drivers/gpu/drm/msm/msm_gem.h | 2 +- drivers/gpu/drm/qxl/qxl_cmd.c | 2 +- drivers/gpu/drm/vboxvideo/vboxvideo.h | 2 +- drivers/gpu/drm/vc4/vc4_drv.h | 2 +- drivers/gpu/drm/vmwgfx/vmwgfx_page_dirty.c | 2 +- drivers/gpu/drm/vmwgfx/vmwgfx_surface.c | 2 +- include/drm/bridge/mhl.h | 4 ++-- include/drm/drm_displayid.h | 2 +- include/uapi/drm/i915_drm.h | 4 ++-- 14 files changed, 17 insertions(+), 17 deletions(-) diff --git a/drivers/gpu/drm/etnaviv/etnaviv_gem.h b/drivers/gpu/drm/etnaviv/etnaviv_gem.h index 6b68fe16041b..98e60df882b6 100644 --- a/drivers/gpu/drm/etnaviv/etnaviv_gem.h +++ b/drivers/gpu/drm/etnaviv/etnaviv_gem.h @@ -105,7 +105,7 @@ struct etnaviv_gem_submit { unsigned int nr_pmrs; struct etnaviv_perfmon_request *pmrs; unsigned int nr_bos; - struct etnaviv_gem_submit_bo bos[0]; + struct etnaviv_gem_submit_bo bos[]; /* No new members here, the previous one is variable-length! */ }; diff --git a/drivers/gpu/drm/gma500/intel_bios.h b/drivers/gpu/drm/gma500/intel_bios.h index a1f9ce9465a5..0e6facf21e33 100644 --- a/drivers/gpu/drm/gma500/intel_bios.h +++ b/drivers/gpu/drm/gma500/intel_bios.h @@ -227,7 +227,7 @@ struct bdb_general_definitions { * number = (block_size - sizeof(bdb_general_definitions))/ * sizeof(child_device_config); */ - struct child_device_config devices[0]; + struct child_device_config devices[]; }; struct bdb_lvds_options { diff --git a/drivers/gpu/drm/i915/display/intel_vbt_defs.h b/drivers/gpu/drm/i915/display/intel_vbt_defs.h index 05c7cbe32eb4..aef7fe932d1a 100644 --- a/drivers/gpu/drm/i915/display/intel_vbt_defs.h +++ b/drivers/gpu/drm/i915/display/intel_vbt_defs.h @@ -462,7 +462,7 @@ struct bdb_general_definitions { * number = (block_size - sizeof(bdb_general_definitions))/ * defs->child_dev_size; */ - u8 devices[0]; + u8 devices[]; } __packed; /* @@ -839,7 +839,7 @@ struct bdb_mipi_config { struct bdb_mipi_sequence { u8 version; - u8 data[0]; /* up to 6 variable length blocks */ + u8 data[]; /* up to 6 variable length blocks */ } __packed; /* diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c index 47561dc29304..5cec79152f17 100644 --- a/drivers/gpu/drm/i915/gt/intel_lrc.c +++ b/drivers/gpu/drm/i915/gt/intel_lrc.c @@ -216,7 +216,7 @@ struct virtual_engine { /* And finally, which physical engines this virtual engine maps onto. */ unsigned int num_siblings; - struct intel_engine_cs *siblings[0]; + struct intel_engine_cs *siblings[]; }; static struct virtual_engine *to_virtual_engine(struct intel_engine_cs *engine) diff --git a/drivers/gpu/drm/i915/i915_gpu_error.h b/drivers/gpu/drm/i915/i915_gpu_error.h index 0d1f6c8ff355..5a6561f7a210 100644 --- a/drivers/gpu/drm/i915/i915_gpu_error.h +++ b/drivers/gpu/drm/i915/i915_gpu_error.h @@ -42,7 +42,7 @@ struct i915_vma_coredump { int num_pages; int page_count; int unused; - u32 *pages[0]; + u32 *pages[]; }; struct i915_request_coredump { diff --git a/drivers/gpu/drm/msm/msm_gem.h b/drivers/gpu/drm/msm/msm_gem.h index 9e0953c2b7ce..37aa556c5f92 100644 --- a/drivers/gpu/drm/msm/msm_gem.h +++ b/drivers/gpu/drm/msm/msm_gem.h @@ -157,7 +157,7 @@ struct msm_gem_submit { uint32_t handle; }; uint64_t iova; - } bos[0]; + } bos[]; }; #endif /* __MSM_GEM_H__ */ diff --git a/drivers/gpu/drm/qxl/qxl_cmd.c b/drivers/gpu/drm/qxl/qxl_cmd.c index ef09dc6bc635..d1086b2a6892 100644 --- a/drivers/gpu/drm/qxl/qxl_cmd.c +++ b/drivers/gpu/drm/qxl/qxl_cmd.c @@ -36,7 +36,7 @@ static int qxl_reap_surface_id(struct qxl_device *qdev, int max_to_reap); struct ring { struct qxl_ring_header header; - uint8_t elements[0]; + uint8_t elements[]; }; struct qxl_ring { diff --git a/drivers/gpu/drm/vboxvideo/vboxvideo.h b/drivers/gpu/drm/vboxvideo/vboxvideo.h index 0592004f71aa..a5de40fe1a76 100644 --- a/drivers/gpu/drm/vboxvideo/vboxvideo.h +++ b/drivers/gpu/drm/vboxvideo/vboxvideo.h @@ -138,7 +138,7 @@ struct vbva_buffer { u32 data_len; /* variable size for the rest of the vbva_buffer area in VRAM. */ - u8 data[0]; + u8 data[]; } __packed; #define VBVA_MAX_RECORD_SIZE (128 * 1024 * 1024) diff --git a/drivers/gpu/drm/vc4/vc4_drv.h b/drivers/gpu/drm/vc4/vc4_drv.h index 6627b20c99e9..282293e6f751 100644 --- a/drivers/gpu/drm/vc4/vc4_drv.h +++ b/drivers/gpu/drm/vc4/vc4_drv.h @@ -65,7 +65,7 @@ struct vc4_perfmon { * Note that counter values can't be reset, but you can fake a reset by * destroying the perfmon and creating a new one. */ - u64 counters[0]; + u64 counters[]; }; struct vc4_dev { diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_page_dirty.c b/drivers/gpu/drm/vmwgfx/vmwgfx_page_dirty.c index f07aa857587c..60cfbfadd3f2 100644 --- a/drivers/gpu/drm/vmwgfx/vmwgfx_page_dirty.c +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_page_dirty.c @@ -69,7 +69,7 @@ struct vmw_bo_dirty { unsigned int ref_count; unsigned long bitmap_size; size_t size; - unsigned long bitmap[0]; + unsigned long bitmap[]; }; /** diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c b/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c index 3ce630aa4fde..ec893cd17b50 100644 --- a/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c @@ -79,7 +79,7 @@ struct vmw_surface_dirty { struct svga3dsurface_cache cache; size_t size; u32 num_subres; - SVGA3dBox boxes[0]; + SVGA3dBox boxes[]; }; static void vmw_user_surface_free(struct vmw_resource *res); diff --git a/include/drm/bridge/mhl.h b/include/drm/bridge/mhl.h index 1cc77bf38324..d96626a0e3fa 100644 --- a/include/drm/bridge/mhl.h +++ b/include/drm/bridge/mhl.h @@ -327,13 +327,13 @@ struct mhl_burst_bits_per_pixel_fmt { struct { u8 stream_id; u8 pixel_format; - } __packed desc[0]; + } __packed desc[]; } __packed; struct mhl_burst_emsc_support { struct mhl3_burst_header hdr; u8 num_entries; - __be16 burst_id[0]; + __be16 burst_id[]; } __packed; struct mhl_burst_audio_descr { diff --git a/include/drm/drm_displayid.h b/include/drm/drm_displayid.h index 9d3b745c3107..94b4390bf990 100644 --- a/include/drm/drm_displayid.h +++ b/include/drm/drm_displayid.h @@ -89,7 +89,7 @@ struct displayid_detailed_timings_1 { struct displayid_detailed_timing_block { struct displayid_block base; - struct displayid_detailed_timings_1 timings[0]; + struct displayid_detailed_timings_1 timings[]; }; #define for_each_displayid_db(displayid, block, idx, length) \ diff --git a/include/uapi/drm/i915_drm.h b/include/uapi/drm/i915_drm.h index 829c0a48577f..33de5dfadaf5 100644 --- a/include/uapi/drm/i915_drm.h +++ b/include/uapi/drm/i915_drm.h @@ -1708,7 +1708,7 @@ struct i915_context_engines_load_balance { __u64 mbz64; /* reserved for future use; must be zero */ - struct i915_engine_class_instance engines[0]; + struct i915_engine_class_instance engines[]; } __attribute__((packed)); #define I915_DEFINE_CONTEXT_ENGINES_LOAD_BALANCE(name__, N__) struct { \ @@ -1746,7 +1746,7 @@ struct i915_context_engines_bond { __u64 flags; /* all undefined flags must be zero */ __u64 mbz64[4]; /* reserved for future use; must be zero */ - struct i915_engine_class_instance engines[0]; + struct i915_engine_class_instance engines[]; } __attribute__((packed)); #define I915_DEFINE_CONTEXT_ENGINES_BOND(name__, N__) struct { \ -- 2.25.0