NetBSD Problem Report #60873

From www@netbsd.org  Tue Oct 13 22:29:40 2026
Return-Path: <www@netbsd.org>
Received: from mail.netbsd.org (mail.netbsd.org [199.233.217.200])
	(using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)
	 key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256
	 client-signature RSA-PSS (2048 bits) client-digest SHA256)
	(Client CN "mail.netbsd.org", Issuer "YR1" (not verified))
	by mollari.NetBSD.org (Postfix) with ESMTPS id 7E4581A923B
	for <gnats-bugs@gnats.NetBSD.org>; Tue, 13 Oct 2026 22:29:40 +0000 (UTC)
Message-Id: <20261013222939.59F3F1A923C@mollari.NetBSD.org>
Date: Tue, 13 Oct 2026 22:29:39 +0000 (UTC)
From: shep971@spectrum.net
Reply-To: shep971@spectrum.net
To: gnats-bugs@NetBSD.org
Subject: amdgpu enabled Kernel crash
X-Send-Pr-Version: www-1.0
X-From4GNATS: "shep971@spectrum.net via gnats" <gnats-admin@NetBSD.org>

>Number:         60873
>Category:       port-amd64
>Synopsis:       amdgpu enabled Kernel crash
>Confidential:   no
>Severity:       non-critical
>Priority:       medium
>Responsible:    port-amd64-maintainer
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Tue Oct 13 22:30:00 +0000 2026
>Last-Modified:  Thu Oct 15 23:00:01 +0000 2026
>Originator:     J. Scott Heppler
>Release:        11.0-Stable 11Oct2026
>Organization:
Retired
>Environment:
Ryzen 5 4600G cpu/gpu
>Description:
Kernel built w/ instructions from nia:
https://www.unitedbsd.com/d/1703-netbsd-amdgpu-testing-in-2026/2
Photo uploaded to thread
>How-To-Repeat:
On Boot
>Fix:
?

>Audit-Trail:
From: "Heppler, J. Scott" <shep971@spectrum.net>
To: gnats-bugs@netbsd.org
Cc: 
Subject: Re: port-amd64/60873: amdgpu enabled Kernel crash
Date: Thu, 15 Oct 2026 15:01:20 -0700

 I'm not sure the hand-held photo of the crash was helpful.

 Here is the hand transcribed dmesg leading up to the crash:
 "[drm] kiq ring mec 2 pipe 1 q 0
 panic: fpudna from kernel . ip 0xffffffff807b459b, trapframe 0xffff868827064ba0
 cpu0: begin traceback
 vpanic() at netbsd:vpanic+0x171
 panic() at netbsd:panic+0x3c"

 If there is anything else that would be helpful, I'll try to generate
 it.

 On Oct 13, 2026: 22:30, gnats-admin@netbsd.org wrote:
 >Thank you very much for your problem report.
 >It has the internal identification `port-amd64/60873'.
 >The individual assigned to look at your
 >report is: port-amd64-maintainer.
 >
 >>Category:       port-amd64
 >>Responsible:    port-amd64-maintainer
 >>Synopsis:       amdgpu enabled Kernel crash
 >>Arrival-Date:   Tue Oct 13 22:30:00 +0000 2026
 >

 -- 
 J. Scott Heppler

 Penguin Innovations

 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 


 NOTICE: This e-mail message and any attachments may
 contain legally privileged and confidential information intended
 solely for the use of the intended recipients. If you are not an
 intended recipient, you are hereby notified that you have
 received this message in error and any review, dissemination,
 distribution, copying, or other unauthorized use of this email
 and any attachment is strictly prohibited. If you have received
 this email in error, please notify the sender immediately and
 delete the message and any attachments from your system.

From: Taylor R Campbell <riastradh@NetBSD.org>
To: gnats-bugs@netbsd.org
Cc: port-amd64-maintainer@netbsd.org, gnats-admin@netbsd.org,
	netbsd-bugs@netbsd.org, shep971@spectrum.net
Subject: Re: port-amd64/60873: amdgpu enabled Kernel crash
Date: Thu, 15 Oct 2026 22:25:46 +0000

 > Date: Thu, 15 Oct 2026 15:01:20 -0700
 > From: "Heppler, J. Scott" <shep971@spectrum.net>
 >=20
 > I'm not sure the hand-held photo of the crash was helpful.
 >=20
 > Here is the hand transcribed dmesg leading up to the crash:
 > "[drm] kiq ring mec 2 pipe 1 q 0
 > panic: fpudna from kernel . ip 0xffffffff807b459b, trapframe 0xffff868827=
 064ba0
 > cpu0: begin traceback
 > vpanic() at netbsd:vpanic+0x171
 > panic() at netbsd:panic+0x3c"
 >=20
 > If there is anything else that would be helpful, I'll try to generate
 > it.

 Are there any lines after that?

 What's happening is:

 1. Something in the kernel is trying to use floating-point/vector
    instructions when it is forbidden (`panic: fpudna').
 2. There is a stack trace showing what part of the kernel was doing
    this.
 3. The stack trace as you shared it stops point where the fpu trap
    handler called panic(), but I want to see what provoked the fpu
    trap handler -- most likely, it's just some small part of the
    amdgpu driver that's missing fpu_kern_enter/leave (we've had a few
    bugs like this before), but we need to find which part of the
    driver that is.

 Or, did you get a crash dump, e.g. /var/crash/netbsd.N.core?

 If so, you may be able to get more info out with:

 $ crash -N /netbsd -M /var/crash/netbsd.N.core

 or

 $ gdb /netbsd
 (gdb) target kvm /var/crash/netbsd.N.core
 (gdb) bt

From: "Heppler, J. Scott" <shep971@spectrum.net>
To: gnats-bugs@netbsd.org
Cc: 
Subject: Re: port-amd64/60873: amdgpu enabled Kernel crash
Date: Thu, 15 Oct 2026 15:56:42 -0700

 Just got the automated gnats instructions:

 crash:
 _kvm_kvatop(0)
 Kernel compiled without options LOCKDEBUG
 crash _kvm_kvatop(3)
 crash:  cannot read *panicstr: ...

 gdb:
 Cannot access memory at 0x473c987027ebde91

 If needed I can build a kernel w/ debugging.

 On Oct 15, 2026: 22:30, Taylor R Campbell via gnats wrote:
 >The following reply was made to PR port-amd64/60873; it has been noted by GNATS.
 >
 >From: Taylor R Campbell <riastradh@NetBSD.org>
 >To: gnats-bugs@netbsd.org
 >Cc: port-amd64-maintainer@netbsd.org, gnats-admin@netbsd.org,
 >	netbsd-bugs@netbsd.org, shep971@spectrum.net
 >Subject: Re: port-amd64/60873: amdgpu enabled Kernel crash
 >Date: Thu, 15 Oct 2026 22:25:46 +0000
 >
 > > Date: Thu, 15 Oct 2026 15:01:20 -0700
 > > From: "Heppler, J. Scott" <shep971@spectrum.net>
 > >=20
 > > I'm not sure the hand-held photo of the crash was helpful.
 > >=20
 > > Here is the hand transcribed dmesg leading up to the crash:
 > > "[drm] kiq ring mec 2 pipe 1 q 0
 > > panic: fpudna from kernel . ip 0xffffffff807b459b, trapframe 0xffff868827=
 > 064ba0
 > > cpu0: begin traceback
 > > vpanic() at netbsd:vpanic+0x171
 > > panic() at netbsd:panic+0x3c"
 > >=20
 > > If there is anything else that would be helpful, I'll try to generate
 > > it.
 >
 > Are there any lines after that?
 >
 > What's happening is:
 >
 > 1. Something in the kernel is trying to use floating-point/vector
 >    instructions when it is forbidden (`panic: fpudna').
 > 2. There is a stack trace showing what part of the kernel was doing
 >    this.
 > 3. The stack trace as you shared it stops point where the fpu trap
 >    handler called panic(), but I want to see what provoked the fpu
 >    trap handler -- most likely, it's just some small part of the
 >    amdgpu driver that's missing fpu_kern_enter/leave (we've had a few
 >    bugs like this before), but we need to find which part of the
 >    driver that is.
 >
 > Or, did you get a crash dump, e.g. /var/crash/netbsd.N.core?
 >
 > If so, you may be able to get more info out with:
 >
 > $ crash -N /netbsd -M /var/crash/netbsd.N.core
 >
 > or
 >
 > $ gdb /netbsd
 > (gdb) target kvm /var/crash/netbsd.N.core
 > (gdb) bt
 >

 -- 
 J. Scott Heppler

 Penguin Innovations

 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 


 NOTICE: This e-mail message and any attachments may
 contain legally privileged and confidential information intended
 solely for the use of the intended recipients. If you are not an
 intended recipient, you are hereby notified that you have
 received this message in error and any review, dissemination,
 distribution, copying, or other unauthorized use of this email
 and any attachment is strictly prohibited. If you have received
 this email in error, please notify the sender immediately and
 delete the message and any attachments from your system.

Home	PR Database Search