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=-26.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT, USER_IN_DEF_DKIM_WL 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 3F229C433DB for ; Mon, 15 Mar 2021 16:59:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 18E4A64DC4 for ; Mon, 15 Mar 2021 16:59:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234609AbhCOQ6p (ORCPT ); Mon, 15 Mar 2021 12:58:45 -0400 Received: from linux.microsoft.com ([13.77.154.182]:51050 "EHLO linux.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231590AbhCOQ6O (ORCPT ); Mon, 15 Mar 2021 12:58:14 -0400 Received: from x64host.home (unknown [47.187.194.202]) by linux.microsoft.com (Postfix) with ESMTPSA id 0D28B20B26FA; Mon, 15 Mar 2021 09:58:12 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 0D28B20B26FA DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1615827493; bh=0gTjptmyQZ07PiZCSnD/YKcvyyL392ig4rm2FEjYn/Y=; h=From:To:Subject:Date:In-Reply-To:References:From; b=R91XTzYfYCb0ZGw7P5w4k2c0wPMwNZx0Cb+QOzipMegJEzUGor2RF4EgdBmkFiCl2 myKycQk1amy6owG1HVBpw2L8EDnrxOhlsmEcvGJNMcxBmYgdrTzwMJWJ4ZHWh8xB4g +vEDShINtXTKrHlAz0KkHIh8BpePpQG/nsUveU70= From: madvenka@linux.microsoft.com To: broonie@kernel.org, mark.rutland@arm.com, jpoimboe@redhat.com, jthierry@redhat.com, catalin.marinas@arm.com, will@kernel.org, linux-arm-kernel@lists.infradead.org, live-patching@vger.kernel.org, linux-kernel@vger.kernel.org, madvenka@linux.microsoft.com Subject: [RFC PATCH v2 3/8] arm64: Terminate the stack trace at TASK_FRAME and EL0_FRAME Date: Mon, 15 Mar 2021 11:57:55 -0500 Message-Id: <20210315165800.5948-4-madvenka@linux.microsoft.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210315165800.5948-1-madvenka@linux.microsoft.com> References: <5997dfe8d261a3a543667b83c902883c1e4bd270> <20210315165800.5948-1-madvenka@linux.microsoft.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: live-patching@vger.kernel.org From: "Madhavan T. Venkataraman" Implement the following checks in the unwinder to detect the terminating frame reliably: - The frame must end in task_pt_regs(task)->stackframe. - The frame type must be either TASK_FRAME or EL0_FRAME. Signed-off-by: Madhavan T. Venkataraman --- arch/arm64/kernel/stacktrace.c | 18 ++++++++++++------ 1 file changed, 12 insertions(+), 6 deletions(-) diff --git a/arch/arm64/kernel/stacktrace.c b/arch/arm64/kernel/stacktrace.c index ad20981dfda4..504cd161339d 100644 --- a/arch/arm64/kernel/stacktrace.c +++ b/arch/arm64/kernel/stacktrace.c @@ -43,16 +43,22 @@ int notrace unwind_frame(struct task_struct *tsk, struct stackframe *frame) { unsigned long fp = frame->fp; struct stack_info info; + struct pt_regs *regs; - /* Terminal record; nothing to unwind */ - if (!fp) - return -ENOENT; + if (!tsk) + tsk = current; + regs = task_pt_regs(tsk); - if (fp & 0xf) + /* Terminal record, nothing to unwind */ + if (fp == (unsigned long) regs->stackframe) { + if (regs->frame_type == TASK_FRAME || + regs->frame_type == EL0_FRAME) + return -ENOENT; return -EINVAL; + } - if (!tsk) - tsk = current; + if (!fp || fp & 0xf) + return -EINVAL; if (!on_accessible_stack(tsk, fp, &info)) return -EINVAL; -- 2.25.1