NetBSD Problem Report #55352

From gson@gson.org  Sat Jun  6 11:17:04 2020
Return-Path: <gson@gson.org>
Received: from mail.netbsd.org (mail.netbsd.org [199.233.217.200])
	(using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits))
	(Client CN "mail.NetBSD.org", Issuer "mail.NetBSD.org CA" (not verified))
	by mollari.NetBSD.org (Postfix) with ESMTPS id A466F1A921E
	for <gnats-bugs@gnats.NetBSD.org>; Sat,  6 Jun 2020 11:17:04 +0000 (UTC)
Message-Id: <20200606111659.37B51253D4C@guava.gson.org>
Date: Sat,  6 Jun 2020 14:16:59 +0300 (EEST)
From: gson@gson.org (Andreas Gustafsson)
Reply-To: gson@gson.org (Andreas Gustafsson)
To: gnats-bugs@NetBSD.org
Subject: access_regs_set_unaligned_pc_0x7 test cases sometimes fail
X-Send-Pr-Version: 3.95

>Number:         55352
>Category:       kern
>Synopsis:       access_regs_set_unaligned_pc_0x7 test cases sometimes fail
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    kamil
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sat Jun 06 11:20:00 +0000 2020
>Last-Modified:  Sat Jun 06 11:22:20 +0000 2020
>Originator:     Andreas Gustafsson
>Release:        NetBSD-current
>Organization:
>Environment:
System: NetBSD
Architecture: x86_64
Machine: amd64
>Description:

The access_regs_set_unaligned_pc_0x7 test case in multiple
lib/libc/sys/t_ptrace_wait* tests is now randomly failing on my amd64
bare metal testbed which runs the tests on a physical HP DL360 G7
system.  Each test case fails in maybe 3/4 of the runs, but there's
six of them, so at least one of them is almost certain to fail in
each run.

Here is a tabular representation of the outcomes of the last 30 test
runs, with passing test cases marked by "-" and failing ones by "X":

  -------------------------XX-X-X-X-X--XXX   lib/libc/sys/t_ptrace_wait3:access_regs_set_unaligned_pc_0x7
  -------------------------X--XXXXX-X-XXXX   lib/libc/sys/t_ptrace_wait4:access_regs_set_unaligned_pc_0x7
  -------------------------X-XX--XXX-X-X-X   lib/libc/sys/t_ptrace_wait6:access_regs_set_unaligned_pc_0x7
  --------------------------XXX-X--XXX-XX-   lib/libc/sys/t_ptrace_wait:access_regs_set_unaligned_pc_0x7
  -------------------------XX-XXXXXX-XXXX-   lib/libc/sys/t_ptrace_waitid:access_regs_set_unaligned_pc_0x7
  -------------------------XXX--XXXXXX---X   lib/libc/sys/t_ptrace_waitpid:access_regs_set_unaligned_pc_0x7

Although the failures are easily reproduced on the system in case,
I'm having a hard time reproducing it on other systems.  None of the
following are failing:

 - Tetsts run in qemu
 - Tests run on a Dell R630 rather than a HP DL360
 - Tests run on the same hardware under NetBSD/i386 rather than NetBSD/amd64
 - The access_regs_set_unaligned_pc_0xN test case for any N other than 7

The first failures appeared after this commit:

  2020.05.31.01.39.33 ad src/sys/dev/acpi/acpi_cpu_cstate.c 1.61

Logs:

  http://www.gson.org/netbsd/bugs/build/amd64-baremetal/commits-2020.05.html#2020.05.31.01.39.33

>How-To-Repeat:

With difficulty.

>Fix:

>Release-Note:

>Audit-Trail:

Responsible-Changed-From-To: kern-bug-people->kamil
Responsible-Changed-By: kamil@NetBSD.org
Responsible-Changed-When: Sat, 06 Jun 2020 13:22:20 +0200
Responsible-Changed-Why:
Take.


>Unformatted:

NetBSD Home
NetBSD PR Database Search

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