From patchwork Fri Mar 13 09:04:59 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Amit Daniel Kachhap X-Patchwork-Id: 11436353 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 9AF7A14B4 for ; Fri, 13 Mar 2020 09:09:15 +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 772F82073E for ; Fri, 13 Mar 2020 09:09:15 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="nblj9TUn" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 772F82073E 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+patchwork-linux-arm=patchwork.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=bT/1dTElrabzCNUfyHi0nf5/zqlOXXuOpzaOY+ek720=; b=nblj9TUnuB9E4lRbw+95361opz K9o/Uqz0XILBEXWHjwW7hZ1y9qZ9pTebUsJXP0tRp+OEhMPJsJiuHz/3KTBksALJPxuA2kQHkH7kS dFZb1F6cv3yNs1abUbCm9z0NVNBf167Kkse1kNXHx8vEOdZ9rlMZYzYjVdFQWrZ52R1uiRG7Ta4PK kI4hWeGr+WYDFnLE7Ztta4tIgAiX4dT4UVE1btFhFxmSBMeVQZJtokSrur5BEPq76kNxPZdQnRjQo N6s+pOuflSInhkhKKFAct0GN2xp/nRpW2H6I6hpsGIlEiGmPpP8LtoHzcc9OuC7k9yRl9e62tDh+9 Gi8pCc1Q==; 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 1jCgJd-0005q9-0Z; Fri, 13 Mar 2020 09:09:13 +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 1jCgGm-0002oD-P7 for linux-arm-kernel@lists.infradead.org; Fri, 13 Mar 2020 09:06:18 +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 25ED6FEC; Fri, 13 Mar 2020 02:06:16 -0700 (PDT) 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 60C223F67D; Fri, 13 Mar 2020 02:06:12 -0700 (PDT) From: Amit Daniel Kachhap To: linux-arm-kernel@lists.infradead.org Subject: [PATCH v7 12/17] arm64: unwind: strip PAC from kernel addresses Date: Fri, 13 Mar 2020 14:34:59 +0530 Message-Id: <1584090304-18043-13-git-send-email-amit.kachhap@arm.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1584090304-18043-1-git-send-email-amit.kachhap@arm.com> References: <1584090304-18043-1-git-send-email-amit.kachhap@arm.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200313_020616_875921_E98F307B X-CRM114-Status: GOOD ( 10.82 ) X-Spam-Score: -2.3 (--) X-Spam-Report: SpamAssassin version 3.4.3 on bombadil.infradead.org summary: Content analysis details: (-2.3 points) pts rule name description ---- ---------------------- -------------------------------------------------- -2.3 RCVD_IN_DNSWL_MED RBL: Sender listed at https://www.dnswl.org/, medium trust [217.140.110.172 listed in list.dnswl.org] 0.0 SPF_HELO_NONE SPF: HELO does not publish an SPF Record -0.0 SPF_PASS SPF: sender matches SPF record 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 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.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. When function graph tracer is used with patchable-function-entry then return_to_handler will also have pac bits so strip it too. Reviewed-by: Kees Cook Acked-by: Catalin Marinas Reviewed-by: James Morse Signed-off-by: Mark Rutland Signed-off-by: Kristina Martsenko [Amit: Re-position ptrauth_strip_insn_pac, comment] Signed-off-by: Amit Daniel Kachhap --- Changes since v6: * Mask PAC bits of return_to_handler in case of FUNCTION_GRAPH_TRACER. incase arch/arm64/kernel/stacktrace.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/arch/arm64/kernel/stacktrace.c b/arch/arm64/kernel/stacktrace.c index a336cb1..139679c 100644 --- a/arch/arm64/kernel/stacktrace.c +++ b/arch/arm64/kernel/stacktrace.c @@ -14,6 +14,7 @@ #include #include +#include #include #include @@ -86,7 +87,7 @@ int notrace unwind_frame(struct task_struct *tsk, struct stackframe *frame) #ifdef CONFIG_FUNCTION_GRAPH_TRACER if (tsk->ret_stack && - (frame->pc == (unsigned long)return_to_handler)) { + (ptrauth_strip_insn_pac(frame->pc) == (unsigned long)return_to_handler)) { struct ftrace_ret_stack *ret_stack; /* * This is a case where function graph tracer has @@ -101,6 +102,8 @@ int notrace unwind_frame(struct task_struct *tsk, struct stackframe *frame) } #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ + frame->pc = ptrauth_strip_insn_pac(frame->pc); + /* * Frames created upon entry from EL0 have NULL FP and PC values, so * don't bother reporting these. Frames created by __noreturn functions