From patchwork Wed Oct 2 10:28:02 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Masahiro Yamada X-Patchwork-Id: 174969 Delivered-To: patch@linaro.org Received: by 2002:a92:7e96:0:0:0:0:0 with SMTP id q22csp567359ill; Wed, 2 Oct 2019 03:30:32 -0700 (PDT) X-Google-Smtp-Source: APXvYqzvYEOXYXfTD2vegPunrtnGYg/WJlw1G5mZEQCpz1PFyJLifpWPxTc/g2AZHpC6Mppo3boL X-Received: by 2002:a50:a57d:: with SMTP id z58mr2915326edb.115.1570012232660; Wed, 02 Oct 2019 03:30:32 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1570012232; cv=none; d=google.com; s=arc-20160816; b=VHXX4p2hT152Eb+gMETJKCwlb7jwboWGmPkWCghYy89mSMdY1FVWsnq60vQ+nQmMBh 7z6yh2hoWJWtbJxaHQE8adfSAZ8C9e0Pl5bgNm/2V9DY/V2R64l8YqITPoyYLOY3mZJx yq+GBoGQzYj1XjskVXaIt55r0dzRRB5zg1iwYvyIAWLa9zkl3LNo/E85jM5LnTIcQgVZ SalD3qQbPQd09BVZttQbSRLd+lmzslATAT1fgL6CG839TNW99iWh2jT1fvEnzwdxXd4Q o5g37LmDTGo9Msls/Sj/+FR134gkMZkmskgJOuUjM0URnOzGeXQBkONLaG8cSyOho+ZJ E/ag== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:message-id:date:subject:cc:to:from :dkim-signature:dkim-filter; bh=mVsEFaGyKR+ONE3aTVtqJGvbA8/KiDyvvo+GI9JBcGU=; b=SNUK1/1tO3KV6orGeJ55lDw3jYSRAUMJQIJYT312qc5UwMCnNC7QslVeR2RxmaZyuJ cmNgkrk4IumOc7j9Ts1d2TA+RLZ1p+dHQMplkoOY6ptydVqQ6a9mfEgl5ExFcp+U6vIG R7EDUZ33LzLL3oHErepOUXDxluJFgeZo4IKAEeaIvNw4S+wBfITdtjbIGS6LldCQlBzt 9/wOR5FR5roG7HpjsQAclG4+9lYW8xB64Py0g07yWFwcGViwja5rpjUnZziRHKGdhg3e lotMyApcmfrPwQ8CEmSdGbAjNuA/Qv6FTpztsiyzFMp7YjHgh9L3uw6Xaocdv6MlF9P8 bB7g== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@nifty.com header.s=dec2015msa header.b=26jD8eFP; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id o32si11778804edb.63.2019.10.02.03.30.32; Wed, 02 Oct 2019 03:30:32 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=pass header.i=@nifty.com header.s=dec2015msa header.b=26jD8eFP; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727930AbfJBKab (ORCPT + 27 others); Wed, 2 Oct 2019 06:30:31 -0400 Received: from conuserg-07.nifty.com ([210.131.2.74]:22674 "EHLO conuserg-07.nifty.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726109AbfJBKab (ORCPT ); Wed, 2 Oct 2019 06:30:31 -0400 Received: from localhost.localdomain (p14092-ipngnfx01kyoto.kyoto.ocn.ne.jp [153.142.97.92]) (authenticated) by conuserg-07.nifty.com with ESMTP id x92ASDI8018024; Wed, 2 Oct 2019 19:28:13 +0900 DKIM-Filter: OpenDKIM Filter v2.10.3 conuserg-07.nifty.com x92ASDI8018024 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nifty.com; s=dec2015msa; t=1570012094; bh=mVsEFaGyKR+ONE3aTVtqJGvbA8/KiDyvvo+GI9JBcGU=; h=From:To:Cc:Subject:Date:From; b=26jD8eFPEWohdp5e0ArWJ5UyL9t2+NssfYmsqRKM5SICqFL04xpXRhBoQK7F4PTLF pTYTaYrlo4ndLWXRAm+AoHkWnYfXE0gxZDC4+zhapqFXbBfQQB3A31s1qJ/gZa7BLD wVW5h27fvLa+x+0NatKW7p7OEm2XjEEWpcB2tFSSDFCyN8ECWoV9wPmlTuvkp2CCu7 rsShxES/GON/v5L91naShlOHQ8NN7Ptxpt1CdDptTIlEfJQ/WYfPqe7b0j9OqcB1li sRAg3wreRPsvirRGD+iOR+bAQcaB6rsegwmRBFrYQMtbYF/5EPA7CHqr7u/rOafrA6 O27F2o0bu/UpQ== X-Nifty-SrcIP: [153.142.97.92] From: Masahiro Yamada To: patches@arm.linux.org.uk Cc: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Russell King , Masahiro Yamada , Enrico Weigelt , Julien Thierry , Russell King , Stefan Agner , Thomas Gleixner , Vincent Whitchurch Subject: [PATCH] ARM: add __always_inline to functions called from __get_user_check() Date: Wed, 2 Oct 2019 19:28:02 +0900 Message-Id: <20191002102802.29691-1-yamada.masahiro@socionext.com> X-Mailer: git-send-email 2.17.1 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 --- KernelVersion: v5.4-rc1 arch/arm/include/asm/domain.h | 8 ++++---- arch/arm/include/asm/uaccess.h | 4 ++-- 2 files changed, 6 insertions(+), 6 deletions(-) -- 2.17.1 diff --git a/arch/arm/include/asm/domain.h b/arch/arm/include/asm/domain.h index 567dbede4785..f1d0a7807cd0 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 303248e5b990..98c6b91be4a8 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 */