Re: kern/50828 (current amd64 kernel crashes at boot)

[Martin Husemann <martin%duskware.de@localhost>]

The following reply was made to PR kern/50828; it has been noted by GNATS.

From: Martin Husemann <martin%duskware.de@localhost>
To: gnats-bugs%NetBSD.org@localhost
Cc: 
Subject: Re: kern/50828 (current amd64 kernel crashes at boot)
Date: Sun, 21 Feb 2016 12:12:14 +0100

 On Fri, Feb 19, 2016 at 09:31:46PM +0100, Martin Husemann wrote:
 > -makeoptions	nouveau	CPPFLAGS+="-DCONFIG_NOUVEAU_DEBUG=5"
 > -makeoptions	nouveau	CPPFLAGS+="-DCONFIG_NOUVEAU_DEBUG_DEFAULT=3"
 > +makeoptions	nouveau	CPPFLAGS+="-DCONFIG_NOUVEAU_DEBUG=0"
 > +makeoptions	nouveau	CPPFLAGS+="-DCONFIG_NOUVEAU_DEBUG_DEFAULT=0"
 
 The crash does not happen always (but most of the time, never needed
 more than two tries), and I have never seen it with a kernel with all
 nouveau debugging turned off.
 
 CONFIG_NOUVEAU_DEBUG=1 is enough to trigger it.
 
 When it crashes, it is in usb device discovery, i.e. cpu 1 is doing:
 
 bus_space_write_1() at netbsd:bus_space_write_1+0xe
 putchar() at netbsd:putchar+0x115
 kprintf() at netbsd:kprintf+0x7c7
 aprint_normal_internal() at netbsd:aprint_normal_internal+0x70
 aprint_normal_dev() at netbsd:aprint_normal_dev+0x4d
 ugen_attach() at netbsd:ugen_attach+0x8b
 config_attach_loc() at netbsd:config_attach_loc+0x16e
 usbd_attachwholedevice() at netbsd:usbd_attachwholedevice+0xa1
 usbd_probe_and_attach() at netbsd:usbd_probe_and_attach+0x12c
 usbd_new_device() at netbsd:usbd_new_device+0x41d
 uhub_explore() at netbsd:uhub_explore+0x215
 usb_discover.isra.0() at netbsd:usb_discover.isra.0+0x3e
 usb_event_thread() at netbsd:usb_event_thread+0x74
 
 and cpu 5 crashes on a NULL deref:
 
 netbsd:usb_task_thread+0x5b:    movq    %rdx,0(%rax)
 
 with
 
  rax         0
 
 All other cpus are idle. Note that I am using serial console here, so putchar
 should not touch the nouveau framebuffer.
 
 Martin