NetBSD Problem Report #55483

From  Sun Jul 12 12:46:29 2020
Return-Path: <>
Received: from ( [])
	(using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits))
	(Client CN "", Issuer " CA" (not verified))
	by (Postfix) with ESMTPS id 2A1ED1A9213
	for <>; Sun, 12 Jul 2020 12:46:29 +0000 (UTC)
Message-Id: <>
Date: Sun, 12 Jul 2020 14:46:19 +0200 (CEST)
Subject: SMEP exception skip topmost stack frame
X-Send-Pr-Version: 3.95

>Number:         55483
>Category:       port-amd64
>Synopsis:       SMEP exception skip topmost stack frame
>Confidential:   no
>Severity:       serious
>Priority:       high
>Responsible:    port-amd64-maintainer
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sun Jul 12 12:50:00 +0000 2020
>Originator:     Martin Husemann
>Release:        NetBSD 9.99.69
The NetBSD Foundation, Inc.
System: NetBSD 9.99.69 NetBSD 9.99.69 (GENERIC) #406: Tue Jun 30 16:36:57 CEST 2020 amd64
Architecture: x86_64
Machine: amd64

The SMEP exception when the kernel jumps through a NULL pointer is nice,
but the ddb trace it ends up with misses the topmost stack frame, so it is
mostly useless for driver developement/kernel debugging.


Make the kernel jump via a NULL function pointer, watch the db backtrace
afterwards and wonder where the jump really happens.


NetBSD Home
NetBSD PR Database Search

(Contact us) $NetBSD: query-full-pr,v 1.46 2020/01/03 16:35:01 leot Exp $
$NetBSD:,v 1.9 2014/08/02 14:16:04 spz Exp $
Copyright © 1994-2020 The NetBSD Foundation, Inc. ALL RIGHTS RESERVED.