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Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.2 #3 (Red Hat Linux)) id 1iFDfV-0002wW-Mo; Tue, 01 Oct 2019 08:38:01 +0000 Received: from conuserg-07.nifty.com ([210.131.2.74]) by bombadil.infradead.org with esmtps (Exim 4.92.2 #3 (Red Hat Linux)) id 1iFDfS-0002w2-Bh for linux-arm-kernel@lists.infradead.org; Tue, 01 Oct 2019 08:38:00 +0000 Received: from localhost.localdomain (p14092-ipngnfx01kyoto.kyoto.ocn.ne.jp [153.142.97.92]) (authenticated) by conuserg-07.nifty.com with ESMTP id x918bGRK010166; Tue, 1 Oct 2019 17:37:16 +0900 DKIM-Filter: OpenDKIM Filter v2.10.3 conuserg-07.nifty.com x918bGRK010166 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nifty.com; s=dec2015msa; t=1569919038; bh=5vgn6LNEnRoez/oiB48qIZvraN4rGfguB7nlITyUZnQ=; h=From:To:Cc:Subject:Date:From; b=p91ffoOa2E/AqaszRIYAKxH64lj7JJFDmZ79GZ/o3VRI/mwetxYYTQsnMaUw14GmA ZVm6pzze0VUYtB3hV7bLkjiHP+ofi+YmdztVAuitDJ3kA93dhWnhTO8TVLFTz6Dl7g XvOobdLSRmBFYm3F1wliVdaWSZMBm6GoDv/aBdFWMv2Rmxw2+0ZeUdVRufx3OS7r0P Hs72Fd2OSDGs662tuHHS+kUJnTYqsSs2+cjjh4jfgQUE+jKBtvSnylC86v6Zs0O5G6 WF0bdsK1XFHCIBi6PJrD9ZiZqjOv17oQVq7jZI87bIrFBpbYdHV9ykA61Q81Qo8YXo +B0Gs6PCTXyTQ== X-Nifty-SrcIP: [153.142.97.92] From: Masahiro Yamada To: linux-arm-kernel@lists.infradead.org, Russell King Subject: [PATCH v2] ARM: add __always_inline to functions called from __get_user_check() Date: Tue, 1 Oct 2019 17:37:01 +0900 Message-Id: <20191001083701.27207-1-yamada.masahiro@socionext.com> X-Mailer: git-send-email 2.17.1 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20191001_013758_622402_10E69C6A X-CRM114-Status: GOOD ( 12.00 ) X-Spam-Score: 1.0 (+) X-Spam-Report: SpamAssassin version 3.4.2 on bombadil.infradead.org summary: Content analysis details: (1.0 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 RCVD_IN_MSPIKE_H2 RBL: Average reputation (+2) [210.131.2.74 listed in wl.mailspike.net] -0.0 RCVD_IN_DNSWL_NONE RBL: Sender listed at https://www.dnswl.org/, no trust [210.131.2.74 listed in list.dnswl.org] 0.0 SPF_HELO_NONE SPF: HELO does not publish an SPF Record 1.0 SPF_SOFTFAIL SPF: sender does not match SPF record (softfail) 0.1 DKIM_SIGNED Message has a DKIM or DK signature, not necessarily valid -0.1 DKIM_VALID Message has at least one valid DKIM or DK signature X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Kate Stewart , Arnd Bergmann , Enrico Weigelt , Vincent Whitchurch , Nick Desaulniers , Russell King , Stefan Agner , linux-kernel@vger.kernel.org, Masahiro Yamada , Allison Randal , Greg Kroah-Hartman , Olof Johansson , Thomas Gleixner , Julien Thierry , Linus Torvalds , Nicolas Saenz Julienne MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.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 also 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 --- Changes in v2: - Use __always_inline instead of changing the function call places (per Russell King) - The previous submission is: https://lore.kernel.org/patchwork/patch/1132459/ 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 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 */