Re: uvmfault (7.99.1/amd64)

[Thomas Klausner <wiz%NetBSD.org@localhost>]

On Sat, Sep 13, 2014 at 07:57:20AM +0100, Nick Hudson wrote:
> On 09/13/14 07:55, Thomas Klausner wrote:
> >My main machine suddenly hung last night and then rebooted. There was
> >no big load on it at that time. dmesg contains:
> >
> >uvm_fault(0xffffffff810157c0, 0xffff8003393c8000, 1) -> e
> >fatal page fault in supervisor mode
> >trap type 6 code 0 rip ffffffff80264fc5 cs 8 rflags 10202 cr2 
> >ffff8003393c8000 ilevel 4 rsp fffffe813d81d720
> >curlwp 0xfffffe813dc10aa0 pid 0.143 lowest kstack 0xfffffe813d81a2c0
> >panic: trap
> >cpu7: Begin traceback...
> >vpanic() at netbsd:vpanic+0x13c
> >snprintf() at netbsd:snprintf
> >startlwp() at netbsd:startlwp
> >cpu7: End traceback...
> >
> >dumping to dev 168,3 (offset=8, size=8373576):
> >dump Copyright (c) 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 
> >2005,
> >(new kernel booting messages follow)
> >
> >I did get a core dump, and I do have a kernel with symbols.
> ># gdb netbsd
> >GNU gdb (GDB) 7.7.1
> >Copyright (C) 2014 Free Software Foundation, Inc.
> >License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
> >This is free software: you are free to change and redistribute it.
> >There is NO WARRANTY, to the extent permitted by law.  Type "show copying"
> >and "show warranty" for details.
> >This GDB was configured as "x86_64--netbsd".
> >Type "show configuration" for configuration details.
> >For bug reporting instructions, please see:
> ><http://www.gnu.org/software/gdb/bugs/>.
> >Find the GDB manual and other documentation resources online at:
> ><http://www.gnu.org/software/gdb/documentation/>.
> >For help, type "help".
> >Type "apropos word" to search for commands related to "word"...
> >Reading symbols from netbsd...done.
> >(gdb) target  kvm netbsd.core
> >0xffffffff805b6ac5 in cpu_reboot (howto=howto@entry=260, 
> >bootstr=bootstr@entry=0x0) at 
> >/archive/foreign/src/sys/arch/amd64/amd64/machdep.c:671
> >671                     dumpsys();
> >(gdb) bt
> >#0  0xffffffff805b6ac5 in cpu_reboot (howto=howto@entry=260, 
> >bootstr=bootstr@entry=0x0) at 
> >/archive/foreign/src/sys/arch/amd64/amd64/machdep.c:671
> >#1  0xffffffff807b0ae4 in vpanic (fmt=fmt@entry=0xffffffff80c51a95 "trap", 
> >ap=ap@entry=0xfffffe813d81d510) at 
> >/archive/foreign/src/sys/kern/subr_prf.c:340
> >#2  0xffffffff807b0b9f in panic (fmt=fmt@entry=0xffffffff80c51a95 "trap") at 
> >/archive/foreign/src/sys/kern/subr_prf.c:256
> >#3  0xffffffff807fc037 in trap (frame=0xfffffe813d81d630) at 
> >/archive/foreign/src/sys/arch/amd64/amd64/trap.c:298
> >#4  0xffffffff8010108e in alltraps ()
> >#5  0xffffffff80264fc5 in .Mmbuf_inner_loop ()
> >#6  0xfffffe8692e23400 in ?? ()
> >#7  0xfffffe813d81d750 in ?? ()
> >#8  0xffffffff804c3b5e in in_delayed_cksum (m=0xffff8003393c8000) at 
> >/archive/foreign/src/sys/netinet/ip_output.c:791
> >Backtrace stopped: previous frame inner to this frame (corrupt stack?)
> >
> >This does not really look like useful information, does it?
> >  Thomas
> >
> >
> Try crash(8). It does a better job of stack traces through traps.

# crash -M netbsd.core -N netbsd 
Crash version 7.99.1, image version 7.99.1.
System panicked: trap
Backtrace from time of crash is available.
crash> bt
_KERNEL_OPT_NVGA_RASTERCONSOLE() at 0
_KERNEL_OPT_IPFILTER_COMPAT() at _KERNEL_OPT_IPFILTER_COMPAT+0x3
vpanic() at vpanic+0x145
snprintf() at snprintf
startlwp() at startlwp
crash> 

That looks weird.
 Thomas