Re: I can't generate a kernel crash core.

[Jose Luis Rodriguez Garcia]

I have been debuging this problem with gdb and printfs in the source
for locate the path.

I have found it fails in:

arch/amd64/amd64/machdep.c:dodumpsys does: psize = bdev_size(dumpdev);
kern/subr_devsw.c:bdev_size calls rv = (*d->d_psize)(dev)
In my case the dev has major 0 and minor 1
(gdb) print bdevsw[0].d_psize
$1 = (int (*)(dev_t)) 0x80a0ad60 

then d->d_psize is the function wdsize

dev/ata/wd.c:wdsize does wd = device_lookup_private(_cd, WDUNIT(dev));
kern/subr_autoconf.c:device_lookup_private does  return
device_private(device_lookup(cd, unit));
kern/subr_autoconf.c:device_lookup fails and returns NULL. This is in
the sentence:


else if ((dv = cd->cd_devs[unit]) != NULL && dv->dv_del_gen != 0)
 dv = NULL;

config_alldevs_unlock(s);

 return dv;

because cd->cd_devs[unit]) is null.

I have checked these values with printf in the function and these are
(executing a reboot -d):
unit: 0
cd->cd_ndevs: 4
dv is assigned NULL in the asignement: dv = cd->cd_devs[unit])

If I check these values when the system is running cd->cd_devs[unit] isn't NULL.
(gdb) print wd_cd->cd_devs[0]
$23 = (device_t) 0xfe8107cc6408
(gdb) print (*wd_cd->cd_devs[0]).dv_del_gen
$24 = 0

It seems that in the ordered shutdow process this structure
(cd->cd_devs[unit] is destroyed, and the dump fails.



This is the log from dmesg. It says "dump area unavailable"
(file src/sys/arch/amd64/amd64/machdep.c line 1156)
.
wd0: detached
atabus0: detached

dumping to dev 0,1 (offset=8410383, size=1046094):
dump area unavailable
rebooting...

The swap device configuration seems ok:
pc2$ swapctl -z
dump device is wd0b


On Sun, Jan 24, 2016 at 11:00 PM, Jose Luis Rodriguez Garcia
 wrote:
> If the kernel hash a panic, the dump is captured, etc. and it works ok
> (kern.dump_on_panic=1).
>
> I can't generate a crash dump of a running system.
>
>
> On Sun, Jan 24, 2016 at 10:28 PM, Jose Luis Rodriguez Garcia
>  wrote:
>> It is NetBSD 7.0 amd64
>>
>> The swap size is 8 GB, and the memory of the PC is 4GB.
>>

Re: I can't generate a kernel crash core.

[Jose Luis Rodriguez Garcia]

If the kernel hash a panic, the dump is captured, etc. and it works ok
(kern.dump_on_panic=1).

I can't generate a crash dump of a running system.


On Sun, Jan 24, 2016 at 10:28 PM, Jose Luis Rodriguez Garcia
 wrote:
> It is NetBSD 7.0 amd64
>
> The swap size is 8 GB, and the memory of the PC is 4GB.
>

I can't generate a kernel crash core.

[Jose Luis Rodriguez Garcia]

It is NetBSD 7.0 amd64

The swap size is 8 GB, and the memory of the PC is 4GB.

This the /etc/sysctl.conf file:
pc2$ grep -v '^#' /etc/sysctl.conf
ddb.onpanic?=0
kern.ipc.shmmax=16000
vfs.generic.usermount=1
machdep.sparse_dump=1
kern.dump_on_panic=1

I have tried with:
reboot 0x100
reboot 0x104

halt|reboot -dq
etc

without sucess.

I have tried to add savecore=yes to /etc/rc.conf.

Doing a halt -dv o reboot -dqx, I can't see any message that it tries to dump.

I have tried also to do a:
sysctl -w kern.dump_on_panic=0, and it didn't work.


pc2# swapctl -l
Device  1K-blocks UsedAvail Capacity  Priority
/dev/wd0b 83895680  8389568 0%0

By the way I have seen a strange thing:

Doing a rcorder , swap1 and swap2 are execute before of savecore. I
thought that savecore that should be executed before of adding swap.

pc2# rcorder *
wdogctl
fsck_root
modules
resize_root
root
ccd
rndctl
cgd
lvm
raidframe
DISKS
swap1
fsck
mountcritlocal
random_seed
bootconf.sh
ttys
pf_boot
ipsec
ipfilter
sysctl
network
wpa_supplicant
dhclient
dhcpcd
ldpd
npf
pf
route6d
routed
rtsold
staticroute
NETWORKING
mountcritremote
sysdb
newsyslog
wscons
syslogd
ppp
named
rtclocaltime
ntpdate
rpcbind
ypserv
ypbind
yppasswdd
mountall
perusertmp
cleartmp
xfs
accounting
amd
dmesg
fccache
veriexec
ldconfig
quota
mountd
nfsd
nfslocking
pwcheck
gpio
ipnat
securelevel
swap2
virecover
altqd
blacklistd
ifwatchd
isdnd
downinterfaces
ipfs
ipmon
kdc
pflogd
racoon
savecore
SERVERS
DAEMON
apmd
bluetooth
bootparams
devpubd
dhcpd
dhcrelay
ftp_proxy
irdaattach
local
lpd
makemandb
mopd
motd
mrouted
ntpd
powerd
rarpd
rbootd
rtadvd
rwho
screenblank
timed
tpctl
LOGIN
xdm
wsmoused
sshd
raidframeparity
postfix
ndbootd
moused
mixerctl
mdnsd
isibootd
iscsi_target
inetd
identd
httpd
hostapd
ftpd
envsys
dbus
cron
pc2#