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 9584ACCA47B for ; Mon, 13 Jun 2022 14:41:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1384900AbiFMOle (ORCPT ); Mon, 13 Jun 2022 10:41:34 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58964 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1385615AbiFMOka (ORCPT ); Mon, 13 Jun 2022 10:40:30 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 61B5CAFAEF; Mon, 13 Jun 2022 04:50:15 -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 ams.source.kernel.org (Postfix) with ESMTPS id A3DA4B80EC8; Mon, 13 Jun 2022 11:50:13 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id EA651C34114; Mon, 13 Jun 2022 11:50:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1655121012; bh=QNxyg8a/EeMSToOh3j6ZgqqKkIM/59Fix+XBI1emb1w=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=qtL9EsBRdgpvuYnw/9Ykn0SVsqQv6Sze/s0RszbzJcoL6TJSWo6rtuIrreTxKLeQ9 Ppjag1myR/fLJMdp/3ShYiilp+v1MLiyzm5BYAv4sAO6ic5NTguUVZ6/6wtAMe861h uI9WZQkXxPViyl36Wbmken7TDxOgoCy66hH88iIc= 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 5.17 239/298] x86/cpu: Elide KCSAN for cpu_has() and friends Date: Mon, 13 Jun 2022 12:12:13 +0200 Message-Id: <20220613094932.337292827@linuxfoundation.org> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20220613094924.913340374@linuxfoundation.org> References: <20220613094924.913340374@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 1261842d006c..49a3b122279e 100644 --- a/arch/x86/include/asm/cpufeature.h +++ b/arch/x86/include/asm/cpufeature.h @@ -51,7 +51,7 @@ 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