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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham 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 0EE6EC433DF for ; Wed, 24 Jun 2020 22:50:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D97992073E for ; Wed, 24 Jun 2020 22:50:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593039058; bh=UsPcBeVv1Rqr8ERJdYj0ADqcOXxfVl4BMzopt1LKGX0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=xzr0ogmFIvM2DR9gSHuTB8YNDR3LcnWvYdGf7u90k3znpSYtRvYwSeCX1pkhM4y6B nMepSAE9/sX09mX4zwSwkq7AcrmdWswGTAOQrbCe3myRU5SLjcfLZLimHaihKNgGsk QWo9ux312o23WFWi1gAvhQWhu3mWVq8LUTE44Xt0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388679AbgFXWu4 (ORCPT ); Wed, 24 Jun 2020 18:50:56 -0400 Received: from mail.kernel.org ([198.145.29.99]:43264 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388364AbgFXWuy (ORCPT ); Wed, 24 Jun 2020 18:50:54 -0400 Received: from localhost (c-67-180-165-146.hsd1.ca.comcast.net [67.180.165.146]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 74D2F2073E; Wed, 24 Jun 2020 22:50:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593039053; bh=UsPcBeVv1Rqr8ERJdYj0ADqcOXxfVl4BMzopt1LKGX0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Bd8+UoJTSFrGXJtiKYWzlIC+Y3XXddwxrKrpVFsrj4mnilokE+0P6gU2AY89HBjOc KxA1XLJuIkUhI1en+zzNDBLcr8zpHDlvgnCS35Q1xTEtpNgRRRnJrXMASyrZ7FHMP+ 4KsMEPR5BJ5MPBJbeSq0AX+0X97fnU/+KyRwqD5s= From: Andy Lutomirski To: X86 ML , LKML Cc: Sasha Levin , Andy Lutomirski Subject: [PATCH 2/3] selftests/x86/fsgsbase: Add a missing memory constraint Date: Wed, 24 Jun 2020 15:50:49 -0700 Message-Id: <432968af67259ca92d68b774a731aff468eae610.1593038991.git.luto@kernel.org> X-Mailer: git-send-email 2.25.4 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The manual call to set_thread_area() via int $0x80 was missing any indication that the descriptor was a pointer, causing gcc to occasionally generate wrong code. Add the missing constraint. Signed-off-by: Andy Lutomirski --- tools/testing/selftests/x86/fsgsbase.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/tools/testing/selftests/x86/fsgsbase.c b/tools/testing/selftests/x86/fsgsbase.c index f47495d2f070..998319553523 100644 --- a/tools/testing/selftests/x86/fsgsbase.c +++ b/tools/testing/selftests/x86/fsgsbase.c @@ -285,7 +285,8 @@ static unsigned short load_gs(void) /* 32-bit set_thread_area */ long ret; asm volatile ("int $0x80" - : "=a" (ret) : "a" (243), "b" (low_desc) + : "=a" (ret), "+m" (*low_desc) + : "a" (243), "b" (low_desc) : "r8", "r9", "r10", "r11"); memcpy(&desc, low_desc, sizeof(desc)); munmap(low_desc, sizeof(desc)); -- 2.25.4