Re: kernel panics with uvideo, savecores and coredumps

[Christoph Egger <Christoph_Egger%gmx.de@localhost>]

Christoph Egger wrote:
> Christoph Egger wrote:
>> Christoph Egger wrote:
>>> Hi,
>>>
>>> I can reproduce kernel panics when two
>>> programs (mplayer and ekiga) *simultanously*
>>> try to access my webcam.
>>>
>>>
>>> In ddb I do "call dumpsys" or "sync" and reboot
>>> blindly (I'm in X when the panic happens).
>>>
>>> On reboot, savecore prints things like
>>>
>>> panic: kmem_poison_check  x != y  (where x and y are numbers)
> 
> More details on this panic:
> 
> panic: kmem_poison_check: 0xffff80004e98e1a0: 0x50 != 0x1a
> 
> db{1}> bt
> breakpoint() at netbsd:breakpoint+0x5
> panic() at netbsd:pani+0x260
> kmem_poison_check() at netbsd:kmem_poison_check+0x82
> kmem_alloc() at netbsd:kmem_alloc+0x58
> amap_alloc() at netbsd:amap_alloc+0x111
> amap_copy() at netbsd:amap_copy+0x34a
> uvM_fault_internal() at netbsd:uvm_fault_internal+0xe53
> trap() at netbsd:trap+0x817
> trap (number 1191182377)
> 0x3830303220332e31:
> db{1}> mach cpu 0
> using cpu 0
> db{1}> bt
> x86_stihlt() at netbsd:x86_stihlt+0x6
> idle_loop() at netbsd:idle_loop+0x18e
> db{1}>
> 
>>> or
>>>
>>> panic: extent_alloc_subregion: bad size

More details on this panic type:

extent_alloc_subregion: extent `ehci0', size 0x96000
panic: extent_alloc_subregion: bad size
db{1}> bt
extent_alloc_subregion1() at netbsd:extent_alloc_subregion1+0x99
extent_alloc() at netbsd:extent_alloc+0x32
usb_reserve_allocm() at netbsd:usb_reserve_allocm+0x64
usbd_alloc_buffer() at netbsd:usbd_alloc_buffer+0x3b
uvideo_start_transfer() at netbsd:netbsd:uvideo_start_transfer+0x16b
video_stream_on() at netbsd:video_stream_on+0x31
videoioctl() at netbsd:videoioctl+0x2d1
cdev_ioctl() at netbsd:cdev_ioctl+0x91
VOP_IOCTL() at netbsd:VOP_IOCTL+0x64
vn_ioctl() at netbsd:vn_ioctl+0x6d
sys_ioctl() at netbsd:sys_ioctl+0x134
syscall() at netbsd:syscall+0xb6
db{1}> machine cpu 0
using CPU0
db{1}> bt
_kernel_loc() at netbsd:_kernel_lock+0xc7
nd6_timer() at netbsd:nd6_timer+0x3f
callout_softclock() at netsbd:callout_softclock+0x2df
softint_dispatch() at netbsd:softint_dispatch+0xd3
DDB lost frame for netbsd:Xsoftintr+0x50, trying 0xffff80004ba73d70
Xsoftintr() at netbsd:Xsoftintr+0x50
--- interrupt ---
0:
db{1}>


>>> To debug a crash dump I following the instructions from:
>>> http://www.netbsd.org/docs/kernel/#debugging_a_kernel_crash_dump
>>>
>>> But I always get backtraces from ddb instead the one from the panic.
>>>
>>> Using ps ax -M netbsd.x.core results in a segfault
>>> in kvm_getproc2() in libkvm.

This part has been fixed.

Christoph