Re: kern/45361: Consistent kernel panic when building qemu in amd64

[Julio Merino <jmmv%NetBSD.org@localhost>]

The following reply was made to PR kern/45361; it has been noted by GNATS.

From: Julio Merino <jmmv%NetBSD.org@localhost>
To: gnats-bugs%NetBSD.org@localhost
Cc: David Holland <dholland-bugs%netbsd.org@localhost>, 
kern-bug-people%netbsd.org@localhost, 
 gnats-admin%netbsd.org@localhost, netbsd-bugs%netbsd.org@localhost
Subject: Re: kern/45361: Consistent kernel panic when building qemu in amd64
Date: Tue, 13 Sep 2011 15:42:59 -0400

 On 9/12/11 4:40 PM, David Holland wrote:
 > The following reply was made to PR kern/45361; it has been noted by GNATS.
 >
 >   Can you at least extract a non-garbled stack trace?
 
 This is all I could get from a new kernel with 
 DEBUG+LOCKDEBUG+DIAGNOSTIC in it, which does not seem that much helpful...
 
 First, these messages popped in /var/log/messages after a first crash:
 
 pmap_kenter_pa: mapping already present
 pmap_kenter_pa: mapping already present
 uvm_fault(0xffff800048c9ed00, 0x0, 1) -> e
 pmap_kenter_pa: mapping already present
 fatal page faultpmap_kenter_pa: mapping already present
 in supervisor mode
 pmap_kenter_pa: mapping already present
 trap type 6 code 0 rip ffffffff80709c2b cs 8 rflags 10297 cr2  20 cpl 6 
 rsp ffff800048ae4990
 panic: trap
 cpu1: Begin traceback...
 startlwp() at netbsd:startlwp
 alltraps() at netbsd:alltraps+0xa2
 kevent1() at netbsd:kevent1+0x2ac
 WARNING: SPL NOT LOWERED ON SYSCALL 16384 3 EXIT f6f308es0y s6_
 __kevent50() at netbsd:sys___kevent50+0x33
 WARNING: SPL NOT LOWERED ON SYSCALL 16384 3 EXIT f6f308e0 6
 syscall() at netbsdW:AsRyNsIcNaGl:l +S0PxLa cN
 OT LOWERED ON SYSCALL 16384 3 EXIT f6f308e0 6
 cpu1: End traceback...
 
 dumping to dev 0,1 offset 2025
 dump WARNING: SPL NOT LOWERED ON SYSCALL 16384 3 EXIT f6f308e0 6
 
 -----
 
 And then, I set ddb.onpanic=1 and retried the test, getting the 
 following crash and subsequent backtrace:
 
 pmap_kenter_pa: mapping already present
 pmap_kenter_pa: mapping already present
 uvm_fault(0xffff800048c9bd00, 0x0, 1) -> e
 pmap_kenter_pa: mapping already present
 fatal page faultpmap_kenter_pa: mapping already present
   in supervisor mode
 pmap_kenter_pa: mapping already present
 trap type 6 code 0 rip ffffffff80709c2b cs 8 rflags 10297 cr2  24 cpl 6 
 rsp ffff800048af3990
 kernel: page fault trap, code=0
 Stopped in pid 221.1 (syslogd) at     netbsd:pool_cache_put_paddr+0x52: 
 cmpq 20(%r15),%rbx
 
 ddb> bt
 pool_cache_put_paddr() at netbsd:pool_cache_put_paddr+0x52
 kevent1() at netbsd:kevent1+0x2ac
 sys___kevent50() at netbsd:sys___kevent50+0x33
 syscall() at netbsd:syscall+0xac