From patchwork Fri Jan 7 19:43:31 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nathan Chancellor X-Patchwork-Id: 12707010 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 9BECEC433F5 for ; Fri, 7 Jan 2022 19:45:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=l90SdDXi3wW6sMHCSVQE2wYqJA/iJrKymNcz7yn8QyI=; b=oYqMger5iZ3Ov+ MSU+EDGxoKu1kUZJQsXAugUZjD13twXtEvtWXcrD5pD457tcqwzcZykByu4Hzv4nDaBj6mFVOvLZ/ 12Yv+kYaDgQr04GJuIv0GnWV5JhKCk17vdZ2q6rLyLwHdx4zT6uwKozWWMYtzsovZUPpOmOZ2fO0p isUK0AYBAwKo0jEVdPAwVpNliaQ3hZjtmDWBpPT9p516m9YgF9fFZXXIXvtht3eNdEQtZMfsuX31/ MqTUKybX9/otTIPO7J1LVM0jqksMRLEuAuP/9zZYYv6j+kbyzHNpuJ5Own6LyWFX9L02l0lIubeTy 6qiXe+JpZjfCXVG7LmoQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1n5v9l-0056MO-8Z; Fri, 07 Jan 2022 19:44:09 +0000 Received: from ams.source.kernel.org ([145.40.68.75]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1n5v9b-0056JL-Dn for linux-arm-kernel@lists.infradead.org; Fri, 07 Jan 2022 19:44:01 +0000 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 14878B82767; Fri, 7 Jan 2022 19:43:58 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id CB022C36AF4; Fri, 7 Jan 2022 19:43:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1641584636; bh=3/20dWOwwSNZJBhLqL6LA9DAw+PK6AmauF9/RAJDr8M=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=kJIvwmZqos7K7pa1InpJaYEK4SDmiJmjsPxdzESJqAZawqFXeZp/R0CVGKQuqoo+e HL0eVs9g/5Ff2dqjjwcqirUvEXHqBZ265xFbpqde7EaGON/X2jfTDHJD/+MMxEp/mb SCOYJjOIrT0PhafvgGYz2Igie681WIg0MHSGOt+34o2sbB9MdpaXskCFJbKYKkGMwt onAiUQNC2HrzjrKWGFynz6b70h7+kTPayinYNm5w/etkS58a07dQjS5D/PtdL0eSVA w9oVc3XgZt2W0lJV2JWt0tl9BMz9mPqbiUBiA9QF0m1lNFsAZNbWktK+J1Ku6Rh4Gn FXrtpPegg1hag== From: Nathan Chancellor To: Greg Kroah-Hartman , Sasha Levin , Catalin Marinas , Will Deacon Cc: Mark Rutland , Marc Zyngier , Nick Desaulniers , linux-arm-kernel@lists.infradead.org, stable@vger.kernel.org, llvm@lists.linux.dev Subject: [PATCH RFC 4.9 1/5] bug: split BUILD_BUG stuff out into Date: Fri, 7 Jan 2022 12:43:31 -0700 Message-Id: <20220107194335.3090066-2-nathan@kernel.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220107194335.3090066-1-nathan@kernel.org> References: <20220107194335.3090066-1-nathan@kernel.org> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220107_114359_776023_BECBE0E2 X-CRM114-Status: GOOD ( 29.11 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org From: Ian Abbott commit bc6245e5efd70c41eaf9334b1b5e646745cb0fb3 upstream. Including pulls in a lot of bloat from and that is not needed to call the BUILD_BUG() family of macros. Split them out into their own header, . Also correct some checkpatch.pl errors for the BUILD_BUG_ON_ZERO() and BUILD_BUG_ON_NULL() macros by adding parentheses around the bitfield widths that begin with a minus sign. Link: http://lkml.kernel.org/r/20170525120316.24473-6-abbotti@mev.co.uk Signed-off-by: Ian Abbott Acked-by: Michal Nazarewicz Acked-by: Kees Cook Cc: Steven Rostedt Cc: Peter Zijlstra Cc: Jakub Kicinski Cc: Rasmus Villemoes Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds [nathan: Just take this patch, not the checkpatch.pl patches before it] Signed-off-by: Nathan Chancellor --- include/linux/bug.h | 72 +-------------------------------- include/linux/build_bug.h | 84 +++++++++++++++++++++++++++++++++++++++ 2 files changed, 85 insertions(+), 71 deletions(-) create mode 100644 include/linux/build_bug.h diff --git a/include/linux/bug.h b/include/linux/bug.h index 0faae96302bd..eafb6213e582 100644 --- a/include/linux/bug.h +++ b/include/linux/bug.h @@ -3,6 +3,7 @@ #include #include +#include enum bug_trap_type { BUG_TRAP_TYPE_NONE = 0, @@ -13,80 +14,9 @@ enum bug_trap_type { struct pt_regs; #ifdef __CHECKER__ -#define __BUILD_BUG_ON_NOT_POWER_OF_2(n) (0) -#define BUILD_BUG_ON_NOT_POWER_OF_2(n) (0) -#define BUILD_BUG_ON_ZERO(e) (0) -#define BUILD_BUG_ON_NULL(e) ((void*)0) -#define BUILD_BUG_ON_INVALID(e) (0) -#define BUILD_BUG_ON_MSG(cond, msg) (0) -#define BUILD_BUG_ON(condition) (0) -#define BUILD_BUG() (0) #define MAYBE_BUILD_BUG_ON(cond) (0) #else /* __CHECKER__ */ -/* Force a compilation error if a constant expression is not a power of 2 */ -#define __BUILD_BUG_ON_NOT_POWER_OF_2(n) \ - BUILD_BUG_ON(((n) & ((n) - 1)) != 0) -#define BUILD_BUG_ON_NOT_POWER_OF_2(n) \ - BUILD_BUG_ON((n) == 0 || (((n) & ((n) - 1)) != 0)) - -/* Force a compilation error if condition is true, but also produce a - result (of value 0 and type size_t), so the expression can be used - e.g. in a structure initializer (or where-ever else comma expressions - aren't permitted). */ -#define BUILD_BUG_ON_ZERO(e) (sizeof(struct { int:-!!(e); })) -#define BUILD_BUG_ON_NULL(e) ((void *)sizeof(struct { int:-!!(e); })) - -/* - * BUILD_BUG_ON_INVALID() permits the compiler to check the validity of the - * expression but avoids the generation of any code, even if that expression - * has side-effects. - */ -#define BUILD_BUG_ON_INVALID(e) ((void)(sizeof((__force long)(e)))) - -/** - * BUILD_BUG_ON_MSG - break compile if a condition is true & emit supplied - * error message. - * @condition: the condition which the compiler should know is false. - * - * See BUILD_BUG_ON for description. - */ -#define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg) - -/** - * BUILD_BUG_ON - break compile if a condition is true. - * @condition: the condition which the compiler should know is false. - * - * If you have some code which relies on certain constants being equal, or - * some other compile-time-evaluated condition, you should use BUILD_BUG_ON to - * detect if someone changes it. - * - * The implementation uses gcc's reluctance to create a negative array, but gcc - * (as of 4.4) only emits that error for obvious cases (e.g. not arguments to - * inline functions). Luckily, in 4.3 they added the "error" function - * attribute just for this type of case. Thus, we use a negative sized array - * (should always create an error on gcc versions older than 4.4) and then call - * an undefined function with the error attribute (should always create an - * error on gcc 4.3 and later). If for some reason, neither creates a - * compile-time error, we'll still have a link-time error, which is harder to - * track down. - */ -#ifndef __OPTIMIZE__ -#define BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)])) -#else -#define BUILD_BUG_ON(condition) \ - BUILD_BUG_ON_MSG(condition, "BUILD_BUG_ON failed: " #condition) -#endif - -/** - * BUILD_BUG - break compile if used. - * - * If you have some code that you expect the compiler to eliminate at - * build time, you should use BUILD_BUG to detect if it is - * unexpectedly used. - */ -#define BUILD_BUG() BUILD_BUG_ON_MSG(1, "BUILD_BUG failed") - #define MAYBE_BUILD_BUG_ON(cond) \ do { \ if (__builtin_constant_p((cond))) \ diff --git a/include/linux/build_bug.h b/include/linux/build_bug.h new file mode 100644 index 000000000000..b7d22d60008a --- /dev/null +++ b/include/linux/build_bug.h @@ -0,0 +1,84 @@ +#ifndef _LINUX_BUILD_BUG_H +#define _LINUX_BUILD_BUG_H + +#include + +#ifdef __CHECKER__ +#define __BUILD_BUG_ON_NOT_POWER_OF_2(n) (0) +#define BUILD_BUG_ON_NOT_POWER_OF_2(n) (0) +#define BUILD_BUG_ON_ZERO(e) (0) +#define BUILD_BUG_ON_NULL(e) ((void *)0) +#define BUILD_BUG_ON_INVALID(e) (0) +#define BUILD_BUG_ON_MSG(cond, msg) (0) +#define BUILD_BUG_ON(condition) (0) +#define BUILD_BUG() (0) +#else /* __CHECKER__ */ + +/* Force a compilation error if a constant expression is not a power of 2 */ +#define __BUILD_BUG_ON_NOT_POWER_OF_2(n) \ + BUILD_BUG_ON(((n) & ((n) - 1)) != 0) +#define BUILD_BUG_ON_NOT_POWER_OF_2(n) \ + BUILD_BUG_ON((n) == 0 || (((n) & ((n) - 1)) != 0)) + +/* + * Force a compilation error if condition is true, but also produce a + * result (of value 0 and type size_t), so the expression can be used + * e.g. in a structure initializer (or where-ever else comma expressions + * aren't permitted). + */ +#define BUILD_BUG_ON_ZERO(e) (sizeof(struct { int:(-!!(e)); })) +#define BUILD_BUG_ON_NULL(e) ((void *)sizeof(struct { int:(-!!(e)); })) + +/* + * BUILD_BUG_ON_INVALID() permits the compiler to check the validity of the + * expression but avoids the generation of any code, even if that expression + * has side-effects. + */ +#define BUILD_BUG_ON_INVALID(e) ((void)(sizeof((__force long)(e)))) + +/** + * BUILD_BUG_ON_MSG - break compile if a condition is true & emit supplied + * error message. + * @condition: the condition which the compiler should know is false. + * + * See BUILD_BUG_ON for description. + */ +#define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg) + +/** + * BUILD_BUG_ON - break compile if a condition is true. + * @condition: the condition which the compiler should know is false. + * + * If you have some code which relies on certain constants being equal, or + * some other compile-time-evaluated condition, you should use BUILD_BUG_ON to + * detect if someone changes it. + * + * The implementation uses gcc's reluctance to create a negative array, but gcc + * (as of 4.4) only emits that error for obvious cases (e.g. not arguments to + * inline functions). Luckily, in 4.3 they added the "error" function + * attribute just for this type of case. Thus, we use a negative sized array + * (should always create an error on gcc versions older than 4.4) and then call + * an undefined function with the error attribute (should always create an + * error on gcc 4.3 and later). If for some reason, neither creates a + * compile-time error, we'll still have a link-time error, which is harder to + * track down. + */ +#ifndef __OPTIMIZE__ +#define BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)])) +#else +#define BUILD_BUG_ON(condition) \ + BUILD_BUG_ON_MSG(condition, "BUILD_BUG_ON failed: " #condition) +#endif + +/** + * BUILD_BUG - break compile if used. + * + * If you have some code that you expect the compiler to eliminate at + * build time, you should use BUILD_BUG to detect if it is + * unexpectedly used. + */ +#define BUILD_BUG() BUILD_BUG_ON_MSG(1, "BUILD_BUG failed") + +#endif /* __CHECKER__ */ + +#endif /* _LINUX_BUILD_BUG_H */