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=-9.0 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,T_DKIMWL_WL_HIGH,URIBL_BLOCKED,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 C2A4BC28CC0 for ; Wed, 29 May 2019 19:06:02 +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 92ED724074 for ; Wed, 29 May 2019 19:06:02 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="s1qo1tv5" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 92ED724074 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=4s2kRVODns7bmhs19XcYE+HHwkMMC6XdJYEFM3PkBTU=; b=s1qo1tv5X/Kw3/Z0QIe0xGHocR q9IA4W8k/yqeZGdMv4S3oel9IPiomffMLRmULZ7roPDohPV/HUvmBnBy+dH+WqE0GnhgWc4utCg1Q 4dmC6cBps8gjZqGxZRITzf+wIVX0jHkf+C+vsgkwamfsshJ8CUXp+EgQWl7C96qde6/icbQmWKpWm XIo6pefHRrcZUp74q29dKTO/ve0y1b0oWRg/5M5DWU3CXx9XJBuvhZP08llIUton26oksinYsTljb +mTS7ab4G78Ah4AIoB5WE+nhEIjrLBo6e6pUeUpCfBrtnWmmINCem6wh5dKjOtiL/m4WXDsNUPBwZ 2a2nurPg==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1hW3ta-0001fV-L4; Wed, 29 May 2019 19:05:54 +0000 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70] helo=foss.arm.com) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1hW3se-0007jO-D3 for linux-arm-kernel@lists.infradead.org; Wed, 29 May 2019 19:04:57 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 186ECA78; Wed, 29 May 2019 12:04:56 -0700 (PDT) Received: from moonbear.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.72.51.249]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 48AF03F59C; Wed, 29 May 2019 12:04:54 -0700 (PDT) From: Kristina Martsenko To: linux-arm-kernel@lists.infradead.org Subject: [RFC v2 6/7] arm64: unwind: strip PAC from kernel addresses Date: Wed, 29 May 2019 20:03:31 +0100 Message-Id: <20190529190332.29753-7-kristina.martsenko@arm.com> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20190529190332.29753-1-kristina.martsenko@arm.com> References: <20190529190332.29753-1-kristina.martsenko@arm.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190529_120456_455137_E4F608BB X-CRM114-Status: GOOD ( 14.58 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , Kees Cook , Ard Biesheuvel , Catalin Marinas , Suzuki K Poulose , Will Deacon , Ramana Radhakrishnan , Amit Kachhap , Dave Martin 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 From: Mark Rutland When we enable pointer authentication in the kernel, LR values saved to the stack will have a PAC which we must strip in order to retrieve the real return address. Strip PACs when unwinding the stack in order to account for this. Reviewed-by: Amit Daniel Kachhap Signed-off-by: Mark Rutland Signed-off-by: Kristina Martsenko --- Changes since RFC v1: - Moved the patch later in the series arch/arm64/include/asm/pointer_auth.h | 10 +++++++--- arch/arm64/kernel/stacktrace.c | 3 +++ 2 files changed, 10 insertions(+), 3 deletions(-) diff --git a/arch/arm64/include/asm/pointer_auth.h b/arch/arm64/include/asm/pointer_auth.h index 79f35f5ecff5..5491c34b4dc3 100644 --- a/arch/arm64/include/asm/pointer_auth.h +++ b/arch/arm64/include/asm/pointer_auth.h @@ -80,12 +80,16 @@ 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_user) +#define ptrauth_user_pac_mask() GENMASK(54, vabits_user) + +#define ptrauth_kernel_pac_mask() (GENMASK(63, 56) | GENMASK(54, VA_BITS)) -/* Only valid for EL0 TTBR0 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) \ diff --git a/arch/arm64/kernel/stacktrace.c b/arch/arm64/kernel/stacktrace.c index d908b5e9e949..df07c27a9673 100644 --- a/arch/arm64/kernel/stacktrace.c +++ b/arch/arm64/kernel/stacktrace.c @@ -24,6 +24,7 @@ #include #include +#include #include #include @@ -56,6 +57,8 @@ int notrace unwind_frame(struct task_struct *tsk, struct stackframe *frame) frame->fp = READ_ONCE_NOCHECK(*(unsigned long *)(fp)); frame->pc = READ_ONCE_NOCHECK(*(unsigned long *)(fp + 8)); + frame->pc = ptrauth_strip_insn_pac(frame->pc); + #ifdef CONFIG_FUNCTION_GRAPH_TRACER if (tsk->ret_stack && (frame->pc == (unsigned long)return_to_handler)) { -- 2.11.0 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel