Panic on -CURRENT after LDT changes

40 msg	[head tinderbox] failure on sparc64/sun4v
36 msg	[head tinderbox] failure on powerpc/powerpc
13 msg	Using Subversion for binary distribution?
19 msg	size of kernel after gcc4.2 upgrade
2 msg	-CURRENT buildworld problems...
1 msg	Testing driver suspend
2 msg	adding ULE in GENERIC options
4 msg	xorg 7.2 install and remote ssh
1 msg	Panic afrer 'installworld'
1 msg	panic from today 7.0-CURRENT
8 msg	problems with perl 5.8.8
5 msg	WITH_HESIOD
10 msg	RELENG_6_2 broken on latest -HEAD

Panic on -CURRENT after LDT changes
\ Joe Marcus Clarke (23 May 2007)
. \ Jeff Roberson (23 May 2007)
. . \ Attilio Rao (24 May 2007)
. . . \ Joe Marcus Clarke (24 May 2007)
. . . . \ Attilio Rao (24 May 2007)
. . . . . \ Joe Marcus Clarke (24 May 2007)
. . . . . . \ Attilio Rao (24 May 2007)
. . . . . \ Joe Marcus Clarke (25 May 2007)
. . . . . . \ Attilio Rao (25 May 2007)
. . . . . . . \ Joe Marcus Clarke (25 May 2007)
. . . . . . . . \ Attilio Rao (25 May 2007)
. . . . . . . . . \ Attilio Rao (25 May 2007)
. . . . . . . . . . \ Joe Marcus Clarke (25 May 2007)
. . . . . . . . . . . \ Attilio Rao (25 May 2007)
. . . . . . . . . . . . \ Joe Marcus Clarke (25 May 2007)
. . . . . . . . . . . . . \ Attilio Rao (26 May 2007)
. . . . . . . . . . . . . . \ Joe Marcus Clarke (26 May 2007)
. . . . . . . . . . . . . . . \ Attilio Rao (26 May 2007)
. . . . . . . . . . . . . . . . \ Joe Marcus Clarke (26 May 2007)
. . . . . . . . . . . . . . . . . \ Tor Egge (28 May 2007)
. . . . . . . . . . . . . . . . . . \ Attilio Rao (28 May 2007)
. . . . . . . . . . . . . . . . . . . \ Attilio Rao (28 May 2007)
. . . . . . . . . . . . . . . . . . . . \ Joe Marcus Clarke (28 May 2007)
. . . . . . . . . . . . . . . . . . . . \ Tor Egge (29 May 2007)

1 msg	kernel page fault with non-sleepable lock
15 msg	Problems compiling some ports after upgrading t...
1 msg	EM now endian clean
11 msg	'make buildkernel' busted
1 msg	ZFS testing problems
9 msg	Re: ZFS committed to the FreeBSD base.

Subject:	Panic on -CURRENT after LDT changes
Group:	Freebsd-current
From:	Joe Marcus Clarke
Date:	23 May 2007

On a -CURRENT build today with Jeff's LDT locking changes, I get an
instant, reproducible panic by doing:

# cd /usr/src
# make -DNO_CLEAN buildworld

Backing out the LDT changes to /sys/i386/i386/*machdep* corrects the
problem. Here is a dmesg and backtrace. In frame 6, it appears mdp is
NULL (i.e. td->td_proc->p_md = 0x0).

http://www.marcuscom.com/downloads/JCLARKE-PC_dump.txt

Unread portion of the kernel message buffer:
kernel trap 12 with interrupts disabled

Fatal trap 12: page fault while in kernel mode
fault virtual address = 0x4
fault code = supervisor read, page not present
instruction pointer = 0x20:0xc0723195
stack pointer = 0x28:0xe768dbf4
frame pointer = 0x28:0xe768dc20
code segment = base 0x0, limit 0xfffff, type 0x1b
= DPL 0, pres 1, def32 1, gran 1
processor eflags = resume, IOPL = 0
current process = 1025 (make)
trap number = 12
panic: page fault
Uptime: 2m37s
Physical memory: 2022 MB
Dumping 65 MB: 50 34 18 2

#0 doadump () at pcpu.h:172
#1 0xc0562c93 in boot (howto=260)
at /usr/src/sys/kern/kern_shutdown.c:409
#2 0xc0562f18 in panic (fmt=Variable "fmt" is not available.
#3 0xc07240b2 in trap_fatal (frame=0xe768dbb4, eva=4)
at /usr/src/sys/i386/i386/trap.c:876
#4 0xc07249a3 in trap (frame=0xe768dbb4)
at /usr/src/sys/i386/i386/trap.c:276
#5 0xc070de5b in calltrap () at /usr/src/sys/i386/i386/exception.s:139
#6 0xc0723195 in i386_ldt_grow (td=Variable "td" is not available.
)
at /usr/src/sys/i386/i386/sys_machdep.c:704
#7 0xc072350a in i386_set_ldt (td=0xc4fccbd0, uap=0xe768dc68,
descs=0xe76f3000) at /usr/src/sys/i386/i386/sys_machdep.c:631
#8 0xc0723a44 in sysarch (td=0xc4fccbd0, uap=0xe768dcfc)
at /usr/src/sys/i386/i386/sys_machdep.c:134
#9 0xc0724645 in syscall (frame=0xe768dd38)
at /usr/src/sys/i386/i386/trap.c:1016
#10 0xc070dec0 in Xint0x80_syscall ()
at /usr/src/sys/i386/i386/exception.s:196
#11 0x00000033 in ?? ()

Joe

--
PGP Key : http://www.marcuscom.com/pgp.asc