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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 971A7FA372C for ; Fri, 8 Nov 2019 19:14:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6301C206A3 for ; Fri, 8 Nov 2019 19:14:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1573240498; bh=bvGk2PFPjcyhGJhlCfWTtMGwXqeLi/+EaaoNSMmvMW0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=O8cpu7OWSXtc5aRYkzxi+qyHbOm8tRnGxxKoJeZRDKRDfLeoL2RiA/lZmxhN5rjx6 k3GOQqXA+C4FfJTTCpwH5/AyjtwymZTnuCo2B2Qp6TeC/S8raZfUD7op2TlOtJvYVV MUNT2DZuVGxGusyNbQ5b4+uszbw1UlHHjq8VB1H8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389305AbfKHTF5 (ORCPT ); Fri, 8 Nov 2019 14:05:57 -0500 Received: from mail.kernel.org ([198.145.29.99]:36114 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731327AbfKHTFy (ORCPT ); Fri, 8 Nov 2019 14:05:54 -0500 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (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 BA33A21D7B; Fri, 8 Nov 2019 19:05:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1573239953; bh=bvGk2PFPjcyhGJhlCfWTtMGwXqeLi/+EaaoNSMmvMW0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=KqCuyFAupjauEVWPoh0hCSk5JAlnSwT9aYN6fc7wAiXjuIkbiQ5XAOLzPaXCVgPlX dl62WAGR8QcR1habuSIP5Tb1OJN0Uf62VSGxtSF+tO1+AkrwaByr28BNo8Aj+dRpj3 s1USxJWm9LzH8uoL0hX1UNGMRvnj5XyabaCcPtGk= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, "kernelci.org bot" , Nicolas Saenz Julienne , Masahiro Yamada , Russell King , Sasha Levin Subject: [PATCH 5.3 039/140] ARM: 8908/1: add __always_inline to functions called from __get_user_check() Date: Fri, 8 Nov 2019 19:49:27 +0100 Message-Id: <20191108174907.870917431@linuxfoundation.org> X-Mailer: git-send-email 2.24.0 In-Reply-To: <20191108174900.189064908@linuxfoundation.org> References: <20191108174900.189064908@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Masahiro Yamada [ Upstream commit 851140ab0d083c78e5723a8b1cbd258f567a7aff ] KernelCI reports that bcm2835_defconfig is no longer booting since commit ac7c3e4ff401 ("compiler: enable CONFIG_OPTIMIZE_INLINING forcibly") (https://lkml.org/lkml/2019/9/26/825). I also received a regression report from Nicolas Saenz Julienne (https://lkml.org/lkml/2019/9/27/263). This problem has cropped up on bcm2835_defconfig because it enables CONFIG_CC_OPTIMIZE_FOR_SIZE. The compiler tends to prefer not inlining functions with -Os. I was able to reproduce it with other boards and defconfig files by manually enabling CONFIG_CC_OPTIMIZE_FOR_SIZE. The __get_user_check() specifically uses r0, r1, r2 registers. So, uaccess_save_and_enable() and uaccess_restore() must be inlined. Otherwise, those register assignments would be entirely dropped, according to my analysis of the disassembly. Prior to commit 9012d011660e ("compiler: allow all arches to enable CONFIG_OPTIMIZE_INLINING"), the 'inline' marker was always enough for inlining functions, except on x86. Since that commit, all architectures can enable CONFIG_OPTIMIZE_INLINING. So, __always_inline is now the only guaranteed way of forcible inlining. I added __always_inline to 4 functions in the call-graph from the __get_user_check() macro. Fixes: 9012d011660e ("compiler: allow all arches to enable CONFIG_OPTIMIZE_INLINING") Reported-by: "kernelci.org bot" Reported-by: Nicolas Saenz Julienne Signed-off-by: Masahiro Yamada Tested-by: Nicolas Saenz Julienne Signed-off-by: Russell King Signed-off-by: Sasha Levin --- arch/arm/include/asm/domain.h | 8 ++++---- arch/arm/include/asm/uaccess.h | 4 ++-- 2 files changed, 6 insertions(+), 6 deletions(-) diff --git a/arch/arm/include/asm/domain.h b/arch/arm/include/asm/domain.h index 567dbede4785c..f1d0a7807cd0e 100644 --- a/arch/arm/include/asm/domain.h +++ b/arch/arm/include/asm/domain.h @@ -82,7 +82,7 @@ #ifndef __ASSEMBLY__ #ifdef CONFIG_CPU_CP15_MMU -static inline unsigned int get_domain(void) +static __always_inline unsigned int get_domain(void) { unsigned int domain; @@ -94,7 +94,7 @@ static inline unsigned int get_domain(void) return domain; } -static inline void set_domain(unsigned val) +static __always_inline void set_domain(unsigned int val) { asm volatile( "mcr p15, 0, %0, c3, c0 @ set domain" @@ -102,12 +102,12 @@ static inline void set_domain(unsigned val) isb(); } #else -static inline unsigned int get_domain(void) +static __always_inline unsigned int get_domain(void) { return 0; } -static inline void set_domain(unsigned val) +static __always_inline void set_domain(unsigned int val) { } #endif diff --git a/arch/arm/include/asm/uaccess.h b/arch/arm/include/asm/uaccess.h index 303248e5b990f..98c6b91be4a8a 100644 --- a/arch/arm/include/asm/uaccess.h +++ b/arch/arm/include/asm/uaccess.h @@ -22,7 +22,7 @@ * perform such accesses (eg, via list poison values) which could then * be exploited for priviledge escalation. */ -static inline unsigned int uaccess_save_and_enable(void) +static __always_inline unsigned int uaccess_save_and_enable(void) { #ifdef CONFIG_CPU_SW_DOMAIN_PAN unsigned int old_domain = get_domain(); @@ -37,7 +37,7 @@ static inline unsigned int uaccess_save_and_enable(void) #endif } -static inline void uaccess_restore(unsigned int flags) +static __always_inline void uaccess_restore(unsigned int flags) { #ifdef CONFIG_CPU_SW_DOMAIN_PAN /* Restore the user access mask */ -- 2.20.1