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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B4C3CCCA47F for ; Mon, 13 Jun 2022 11:46:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1354830AbiFMLqm (ORCPT ); Mon, 13 Jun 2022 07:46:42 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43108 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1357203AbiFMLpr (ORCPT ); Mon, 13 Jun 2022 07:45:47 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 16A2549F3C; Mon, 13 Jun 2022 03:51:51 -0700 (PDT) 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 dfw.source.kernel.org (Postfix) with ESMTPS id 01B5A6128D; Mon, 13 Jun 2022 10:51:51 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0EB20C34114; Mon, 13 Jun 2022 10:51:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1655117510; bh=ZxmjvAyRXC2LFYdT7yWmSVT58DifZY7x0GFuK+Fi3t4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=yiNGrFuzHRrv1+uWNX+4glWDMMH0ACMh/xy2WYQ2Bcfzx5+0sZpdZQNgEs1L+hpln uBVN4qyybQhIoHNSpNWiGi0YGi6opgetCGWV/xaVEPbjYScekRmEY5UTzhhhoANV0u S9oK4rljNWaZZyU/0naooxDCTsh7gAy20L9IuhmA= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, kernel test robot , "Peter Zijlstra (Intel)" , Sasha Levin Subject: [PATCH 5.4 391/411] x86/cpu: Elide KCSAN for cpu_has() and friends Date: Mon, 13 Jun 2022 12:11:04 +0200 Message-Id: <20220613094940.395596079@linuxfoundation.org> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20220613094928.482772422@linuxfoundation.org> References: <20220613094928.482772422@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Peter Zijlstra [ Upstream commit a6a5eb269f6f3a2fe392f725a8d9052190c731e2 ] As x86 uses the headers, the regular forms of all bitops are instrumented with explicit calls to KASAN and KCSAN checks. As these are explicit calls, these are not suppressed by the noinstr function attribute. This can result in calls to those check functions in noinstr code, which objtool warns about: vmlinux.o: warning: objtool: enter_from_user_mode+0x24: call to __kcsan_check_access() leaves .noinstr.text section vmlinux.o: warning: objtool: syscall_enter_from_user_mode+0x28: call to __kcsan_check_access() leaves .noinstr.text section vmlinux.o: warning: objtool: syscall_enter_from_user_mode_prepare+0x24: call to __kcsan_check_access() leaves .noinstr.text section vmlinux.o: warning: objtool: irqentry_enter_from_user_mode+0x24: call to __kcsan_check_access() leaves .noinstr.text section Prevent this by using the arch_*() bitops, which are the underlying bitops without explciit instrumentation. [null: Changelog] Reported-by: kernel test robot Signed-off-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/20220502111216.290518605@infradead.org Signed-off-by: Sasha Levin --- arch/x86/include/asm/cpufeature.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h index 59bf91c57aa8..619c1f80a2ab 100644 --- a/arch/x86/include/asm/cpufeature.h +++ b/arch/x86/include/asm/cpufeature.h @@ -49,7 +49,7 @@ extern const char * const x86_power_flags[32]; extern const char * const x86_bug_flags[NBUGINTS*32]; #define test_cpu_cap(c, bit) \ - test_bit(bit, (unsigned long *)((c)->x86_capability)) + arch_test_bit(bit, (unsigned long *)((c)->x86_capability)) /* * There are 32 bits/features in each mask word. The high bits -- 2.35.1