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=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 0EC6CC3F2D5 for ; Fri, 6 Mar 2020 06:39:16 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id B5E232072D for ; Fri, 6 Mar 2020 06:39:15 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="XyNI++u5" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B5E232072D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:MIME-Version:Cc:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id:References: In-Reply-To:Message-Id:Date:Subject:To:From:Reply-To:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Owner; bh=EYltoVNAE9H5RyXwzCGO/PVZ+hZhneLFZUHnDaAW9/U=; b=XyNI++u5hIBPlH+yaNEyCFkTUO bvkelJkiuaxvxgBGXVxz17K2u8YDhoD79Nwz8lt6Of+OutwUv3MPyTakQicPNGgiFjf4u/Vjk9Vac +buE3ZqQBsltR1P6CqbJFuHBmFHi+NvUCROQMbjq6K9xbkwMDvWWGdsU5qbxNIZHUUCGUmFmq0jMW rW0LOQmUyD9Cf20ErfnzlEJ2PNdJg93q73ynnkQBOwje/FEJn3mUYMbqQEPGGdpIifdix549ZlVnz yrsFSBClOaUhVwElHmf2H6T6uM2VF+r7yMDXxWF3dhc8btX/cqGrytjmfIlHLsD4JtzB9W/7ONsID 839a10kQ==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jA6dc-0007fN-7C; Fri, 06 Mar 2020 06:39:12 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jA6ay-0005JO-Pd for linux-arm-kernel@lists.infradead.org; Fri, 06 Mar 2020 06:36:30 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 6812230E; Thu, 5 Mar 2020 22:36:28 -0800 (PST) Received: from a075553-lin.blr.arm.com (a075553-lin.blr.arm.com [10.162.17.32]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 67F103F6CF; Thu, 5 Mar 2020 22:40:20 -0800 (PST) From: Amit Daniel Kachhap To: linux-arm-kernel@lists.infradead.org Subject: [PATCH v6 12/18] arm64: mask PAC bits of __builtin_return_address Date: Fri, 6 Mar 2020 12:05:19 +0530 Message-Id: <1583476525-13505-13-git-send-email-amit.kachhap@arm.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1583476525-13505-1-git-send-email-amit.kachhap@arm.com> References: <1583476525-13505-1-git-send-email-amit.kachhap@arm.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200305_223628_948970_F453DAEA X-CRM114-Status: GOOD ( 16.92 ) 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: Mark Rutland , Kees Cook , Suzuki K Poulose , Catalin Marinas , Kristina Martsenko , Dave Martin , Mark Brown , James Morse , Ramana Radhakrishnan , Amit Daniel Kachhap , Vincenzo Frascino , Will Deacon , Ard Biesheuvel MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org This redefines __builtin_return_address to mask pac bits when Pointer Authentication is enabled. As __builtin_return_address is used mostly used to refer to the caller function symbol address so masking runtime generated pac bits will help to find the match. This patch adds a new file (asm/compiler.h) and is transitively included (via include/compiler_types.h) on the compiler command line so it is guaranteed to be loaded and the users of this macro will not find a wrong version. A helper macro ptrauth_kernel_pac_mask is created for this purpose and added in this file. A similar macro ptrauth_user_pac_mask exists in pointer_auth.h and is now moved here for the sake of consistency. This change fixes the utilities like cat /proc/vmallocinfo to show correct symbol names. Signed-off-by: Amit Daniel Kachhap --- arch/arm64/Kconfig | 1 + arch/arm64/include/asm/compiler.h | 20 ++++++++++++++++++++ arch/arm64/include/asm/pointer_auth.h | 13 +++++-------- 3 files changed, 26 insertions(+), 8 deletions(-) create mode 100644 arch/arm64/include/asm/compiler.h diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 87e2cbb..115ceea 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -118,6 +118,7 @@ config ARM64 select HAVE_ALIGNED_STRUCT_PAGE if SLUB select HAVE_ARCH_AUDITSYSCALL select HAVE_ARCH_BITREVERSE + select HAVE_ARCH_COMPILER_H select HAVE_ARCH_HUGE_VMAP select HAVE_ARCH_JUMP_LABEL select HAVE_ARCH_JUMP_LABEL_RELATIVE diff --git a/arch/arm64/include/asm/compiler.h b/arch/arm64/include/asm/compiler.h new file mode 100644 index 0000000..085e7cd0 --- /dev/null +++ b/arch/arm64/include/asm/compiler.h @@ -0,0 +1,20 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __ASM_COMPILER_H +#define __ASM_COMPILER_H + +#if defined(CONFIG_ARM64_PTR_AUTH) + +/* + * The EL0/EL1 pointer bits used by a pointer authentication code. + * This is dependent on TBI0/TBI1 being enabled, or bits 63:56 would also apply. + */ +#define ptrauth_user_pac_mask() GENMASK_ULL(54, vabits_actual) +#define ptrauth_kernel_pac_mask() GENMASK_ULL(63, vabits_actual) + +#define __builtin_return_address(val) \ + (void *)((unsigned long)__builtin_return_address(val) | \ + ptrauth_kernel_pac_mask()) + +#endif /* CONFIG_ARM64_PTR_AUTH */ + +#endif /* __ASM_COMPILER_H */ diff --git a/arch/arm64/include/asm/pointer_auth.h b/arch/arm64/include/asm/pointer_auth.h index 833d3f9..5340dbb 100644 --- a/arch/arm64/include/asm/pointer_auth.h +++ b/arch/arm64/include/asm/pointer_auth.h @@ -68,16 +68,13 @@ static __always_inline void ptrauth_keys_switch_kernel(struct ptrauth_keys_kerne extern int ptrauth_prctl_reset_keys(struct task_struct *tsk, unsigned long arg); -/* - * The EL0 pointer bits used by a pointer authentication code. - * This is dependent on TBI0 being enabled, or bits 63:56 would also apply. - */ -#define ptrauth_user_pac_mask() GENMASK(54, vabits_actual) - -/* Only valid for EL0 TTBR0 instruction pointers */ +/* Valid for EL0 TTBR0 and EL1 TTBR1 instruction pointers */ static inline unsigned long ptrauth_strip_insn_pac(unsigned long ptr) { - return ptr & ~ptrauth_user_pac_mask(); + if (ptr & BIT_ULL(55)) + return ptr | ptrauth_kernel_pac_mask(); + else + return ptr & ~ptrauth_user_pac_mask(); } #define ptrauth_thread_init_user(tsk) \ -- 2.7.4 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel