From patchwork Tue Jul 19 14:04:18 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Gwan-gyeong Mun X-Patchwork-Id: 12922567 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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 80024C433EF for ; Tue, 19 Jul 2022 14:06:36 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 10D6018BA17; Tue, 19 Jul 2022 14:06:06 +0000 (UTC) Received: from mga18.intel.com (mga18.intel.com [134.134.136.126]) by gabe.freedesktop.org (Postfix) with ESMTPS id 1833018B9B0; Tue, 19 Jul 2022 14:05:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1658239553; x=1689775553; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=4BjZAzwf/cjjGZ8Cq4DpK5OBKMVSkZXCcRJwdoNKPns=; b=Vz0vwH1MxNd/gk3SkbJ+FVOOGTGMUUb+bCsrdh4eciatnhvXq0vUCsmJ /6kMHJltWbBGSPp2klh3Ov7sAViNpVyOhnHA6x5DEAlxdjYv0b1CABtmS 8Rp8ae/HzgzCMpsomwKVt4m9ZdC5nTYDmouYzNxCWyWNKbzMObPsHHlo8 OibFavCRlRIXy583mB29JSOpOqF5Np241T+Wdb5b7hncbRkrBTlFB3ocK E9g5FBJtT4/Fj2iX9hQC+goyT6X2iSvBmzRBIIqEMujNXeozlXbfwjVlF 8df529OGeiJUDrAaGsNeWx+RgV89DOJkIgLy3t+j5Ir/2R0kZyB4qJUO/ w==; X-IronPort-AV: E=McAfee;i="6400,9594,10412"; a="269523311" X-IronPort-AV: E=Sophos;i="5.92,284,1650956400"; d="scan'208";a="269523311" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by orsmga106.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 19 Jul 2022 07:05:31 -0700 X-IronPort-AV: E=Sophos;i="5.92,284,1650956400"; d="scan'208";a="655773697" Received: from unknown (HELO hades.ger.corp.intel.com) ([10.252.55.53]) by fmsmga008-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 19 Jul 2022 07:05:28 -0700 From: Gwan-gyeong Mun To: intel-gfx@lists.freedesktop.org Date: Tue, 19 Jul 2022 17:04:18 +0300 Message-Id: <20220719140424.430572-2-gwan-gyeong.mun@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220719140424.430572-1-gwan-gyeong.mun@intel.com> References: <20220719140424.430572-1-gwan-gyeong.mun@intel.com> MIME-Version: 1.0 Subject: [Intel-gfx] [PATCH v4 1/7] drm: Move and add a few utility macros into drm util header X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: thomas.hellstrom@linux.intel.com, jani.nikula@intel.com, dri-devel@lists.freedesktop.org, chris@chris-wilson.co.uk, airlied@linux.ie, matthew.auld@intel.com, mchehab@kernel.org, nirmoy.das@intel.com Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" It moves overflows_type utility macro into drm util header from i915_utils header. The overflows_type can be used to catch the truncation between data types. And it adds safe_conversion() macro which performs a type conversion (cast) of an source value into a new variable, checking that the destination is large enough to hold the source value. And it adds exact_type and exactly_pgoff_t macro to catch type mis-match while compiling. v3: Add is_type_unsigned() macro (Mauro) Modify overflows_type() macro to consider signed data types (Mauro) Fix the problem that safe_conversion() macro always returns true v4: Fix kernel-doc markups Signed-off-by: Gwan-gyeong Mun Cc: Thomas Hellström Cc: Matthew Auld Cc: Nirmoy Das Cc: Jani Nikula Reviewed-by: Mauro Carvalho Chehab --- drivers/gpu/drm/i915/i915_utils.h | 5 +- include/drm/drm_util.h | 77 +++++++++++++++++++++++++++++++ 2 files changed, 78 insertions(+), 4 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_utils.h b/drivers/gpu/drm/i915/i915_utils.h index c10d68cdc3ca..345e5b2dc1cd 100644 --- a/drivers/gpu/drm/i915/i915_utils.h +++ b/drivers/gpu/drm/i915/i915_utils.h @@ -32,6 +32,7 @@ #include #include #include +#include #ifdef CONFIG_X86 #include @@ -111,10 +112,6 @@ bool i915_error_injected(void); #define range_overflows_end_t(type, start, size, max) \ range_overflows_end((type)(start), (type)(size), (type)(max)) -/* Note we don't consider signbits :| */ -#define overflows_type(x, T) \ - (sizeof(x) > sizeof(T) && (x) >> BITS_PER_TYPE(T)) - #define ptr_mask_bits(ptr, n) ({ \ unsigned long __v = (unsigned long)(ptr); \ (typeof(ptr))(__v & -BIT(n)); \ diff --git a/include/drm/drm_util.h b/include/drm/drm_util.h index 79952d8c4bba..1de9ee5704fa 100644 --- a/include/drm/drm_util.h +++ b/include/drm/drm_util.h @@ -62,6 +62,83 @@ */ #define for_each_if(condition) if (!(condition)) {} else +/** + * is_type_unsigned - helper for checking data type which is an unsigned data + * type or not + * @x: The data type to check + * + * Returns: + * True if the data type is an unsigned data type, false otherwise. + */ +#define is_type_unsigned(x) ((typeof(x))-1 >= (typeof(x))0) + +/** + * overflows_type - helper for checking the truncation between data types + * @x: Source for overflow type comparison + * @T: Destination for overflow type comparison + * + * It compares the values and size of each data type between the first and + * second argument to check whether truncation can occur when assigning the + * first argument to the variable of the second argument. + * Source and Destination can be used with or without sign bit. + * Composite data structures such as union and structure are not considered. + * Enum data types are not considered. + * Floating point data types are not considered. + * + * Returns: + * True if truncation can occur, false otherwise. + */ + +#define overflows_type(x, T) \ + (is_type_unsigned(x) ? \ + is_type_unsigned(T) ? \ + (sizeof(x) > sizeof(T) && (x) >> BITS_PER_TYPE(T)) ? 1 : 0 \ + : (sizeof(x) >= sizeof(T) && (x) >> (BITS_PER_TYPE(T) - 1)) ? 1 : 0 \ + : is_type_unsigned(T) ? \ + ((x) < 0) ? 1 : (sizeof(x) > sizeof(T) && (x) >> BITS_PER_TYPE(T)) ? 1 : 0 \ + : (sizeof(x) > sizeof(T)) ? \ + ((x) < 0) ? (((x) * -1) >> BITS_PER_TYPE(T)) ? 1 : 0 \ + : ((x) >> BITS_PER_TYPE(T)) ? 1 : 0 \ + : 0) + +/** + * exact_type - break compile if source type and destination value's type are + * not the same + * @T: Source type + * @n: Destination value + * + * It is a helper macro for a poor man's -Wconversion: only allow variables of + * an exact type. It determines whether the source type and destination value's + * type are the same while compiling, and it breaks compile if two types are + * not the same + */ +#define exact_type(T, n) \ + BUILD_BUG_ON(!__builtin_constant_p(n) && !__builtin_types_compatible_p(T, typeof(n))) + +/** + * exactly_pgoff_t - helper to check if the type of a value is pgoff_t + * @n: value to compare pgoff_t type + * + * It breaks compile if the argument value's type is not pgoff_t type. + */ +#define exactly_pgoff_t(n) exact_type(pgoff_t, n) + +/** + * safe_conversion - perform a type conversion (cast) of an source value into + * a new variable, checking that the destination is large enough to hold the + * source value. + * @ptr: Destination pointer address + * @value: Source value + * + * Returns: + * If the value would overflow the destination, it returns false. + */ +#define safe_conversion(ptr, value) ({ \ + typeof(value) __v = (value); \ + typeof(ptr) __ptr = (ptr); \ + overflows_type(__v, *__ptr) ? 0 : ((*__ptr = (typeof(*__ptr))__v), 1); \ +}) + /** * drm_can_sleep - returns true if currently okay to sleep *