NetBSD Problem Report #53643

From martin@duskware.de  Sat Sep 29 22:40:19 2018
Return-Path: <martin@duskware.de>
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 168B07A159
	for <gnats-bugs@gnats.NetBSD.org>; Sat, 29 Sep 2018 22:40:19 +0000 (UTC)
From: martin@NetBSD.org
Reply-To: martin@NetBSD.org
To: gnats-bugs@NetBSD.org
Subject: gdb on core files fails on arm
X-Send-Pr-Version: 3.95

>Number:         53643
>Category:       toolchain
>Synopsis:       gdb on core files fails on arm
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    toolchain-manager
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sat Sep 29 22:45:00 +0000 2018
>Last-Modified:  Sun Sep 30 09:55:00 +0000 2018
>Originator:     Martin Husemann
>Release:        NetBSD 8.99.25
>Organization:
The NetBSD Foundation, Inc.
>Environment:
System: NetBSD space-truckin.duskware.de 8.99.25 NetBSD 8.99.25 (SUNXI) #78: Sat Sep 29 20:54:01 CEST 2018 martin@night-owl.duskware.de:/usr/src/sys/arch/evbarm/compile/SUNXI evbarm
Architecture: earmv7hfeb
Machine: evbarm
>Description:

The new openssl does not work well on arm. I get various core files, but
looking at them seems to be unreliable:

Core was generated by `ssh-add'.
Program terminated with signal SIGILL, Illegal instruction.
#0  0x6f559468 in _armv7_tick () from /usr/lib/libcrypto.so.14
(gdb) bt
#0  0x6f559468 in _armv7_tick () from /usr/lib/libcrypto.so.14
Register 25 is not available

Note that even the pc register is likely wrong - the instruction it points
at is not illegal on this cpu, and tracing through the call in live
instances does not throw a SIGILL.

>How-To-Repeat:
Just use gdb on a core file on arm. Maybe special for big endian arm?

>Fix:
n/a

>Audit-Trail:
From: christos@zoulas.com (Christos Zoulas)
To: gnats-bugs@NetBSD.org, toolchain-manager@netbsd.org, 
	gnats-admin@netbsd.org, netbsd-bugs@netbsd.org
Cc: 
Subject: Re: toolchain/53643: gdb on core files fails on arm
Date: Sat, 29 Sep 2018 21:56:09 -0400

 On Sep 29, 10:45pm, martin@NetBSD.org (martin@NetBSD.org) wrote:
 -- Subject: toolchain/53643: gdb on core files fails on arm

 | >Number:         53643
 | >Category:       toolchain
 | >Synopsis:       gdb on core files fails on arm
 | >Confidential:   no
 | >Severity:       serious
 | >Priority:       medium
 | >Responsible:    toolchain-manager
 | >State:          open
 | >Class:          sw-bug
 | >Submitter-Id:   net
 | >Arrival-Date:   Sat Sep 29 22:45:00 +0000 2018
 | >Originator:     Martin Husemann
 | >Release:        NetBSD 8.99.25
 | >Organization:
 | The NetBSD Foundation, Inc.
 | >Environment:
 | System: NetBSD space-truckin.duskware.de 8.99.25 NetBSD 8.99.25 (SUNXI) #78: Sat Sep 29 20:54:01 CEST 2018 martin@night-owl.duskware.de:/usr/src/sys/arch/evbarm/compile/SUNXI evbarm
 | Architecture: earmv7hfeb
 | Machine: evbarm
 | >Description:
 | 
 | The new openssl does not work well on arm. I get various core files, but
 | looking at them seems to be unreliable:
 | 
 | Core was generated by `ssh-add'.
 | Program terminated with signal SIGILL, Illegal instruction.
 | #0  0x6f559468 in _armv7_tick () from /usr/lib/libcrypto.so.14
 | (gdb) bt
 | #0  0x6f559468 in _armv7_tick () from /usr/lib/libcrypto.so.14
 | Register 25 is not available
 | 
 | Note that even the pc register is likely wrong - the instruction it points
 | at is not illegal on this cpu, and tracing through the call in live
 | instances does not throw a SIGILL.
 | 
 | >How-To-Repeat:
 | Just use gdb on a core file on arm. Maybe special for big endian arm?

 This is on BE arm only? I can't reproduce any of it on LE arm (RPi 2)

 christos

From: matthew green <mrg@eterna.com.au>
To: gnats-bugs@NetBSD.org, martin@netbsd.org
Cc: toolchain-manager@netbsd.org, gnats-admin@netbsd.org,
    netbsd-bugs@netbsd.org
Subject: re: toolchain/53643: gdb on core files fails on arm
Date: Sun, 30 Sep 2018 13:45:32 +1000

 > The new openssl does not work well on arm. I get various core files, but
 > looking at them seems to be unreliable:
 > 
 > Core was generated by `ssh-add'.
 > Program terminated with signal SIGILL, Illegal instruction.
 > #0  0x6f559468 in _armv7_tick () from /usr/lib/libcrypto.so.14
 > (gdb) bt
 > #0  0x6f559468 in _armv7_tick () from /usr/lib/libcrypto.so.14
 > Register 25 is not available
 > 
 > Note that even the pc register is likely wrong - the instruction it points
 > at is not illegal on this cpu, and tracing through the call in live
 > instances does not throw a SIGILL.

 are there any CFI markers in the asm?  there isn't for x86 last
 i saw, and they're needed for properly traversing stack traces
 into these asm files.  i'd guess that's probably the problem..


 .mrg.

From: Martin Husemann <martin@duskware.de>
To: Christos Zoulas <christos@zoulas.com>
Cc: gnats-bugs@NetBSD.org
Subject: Re: toolchain/53643: gdb on core files fails on arm
Date: Sun, 30 Sep 2018 09:56:34 +0200

 On Sat, Sep 29, 2018 at 09:56:09PM -0400, Christos Zoulas wrote:
 > | >How-To-Repeat:
 > | Just use gdb on a core file on arm. Maybe special for big endian arm?
 > 
 > This is on BE arm only? I can't reproduce any of it on LE arm (RPi 2)

 The openssl issue seems to be BE only, I don't know about the core
 dump one (which is what this PR is about).

 Why would the processor status (register 25 in gdb speak) not be available
 in a core? Can I still trust the other registers, given that $PC doesn't
 seem to make any sense? Note that it is not SIGILLing on one of the
 armv8 instructions it tests, but on the single armv7 one that should not
 generate a trap on this CPU (only if run under xen or something).

 Martin

From: Martin Husemann <martin@duskware.de>
To: gnats-bugs@NetBSD.org
Cc: 
Subject: Re: toolchain/53643: gdb on core files fails on arm
Date: Sun, 30 Sep 2018 11:51:18 +0200

 The SIGILL this core reported happened in a thread program, and not in the
 main thread. Maybe this related.

 Martin

NetBSD Home
NetBSD PR Database Search

(Contact us) $NetBSD: query-full-pr,v 1.43 2018/01/16 07:36:43 maya Exp $
$NetBSD: gnats_config.sh,v 1.9 2014/08/02 14:16:04 spz Exp $
Copyright © 1994-2017 The NetBSD Foundation, Inc. ALL RIGHTS RESERVED.