kern/132852: LOR between sysctl and acpi_ibm

[michal at hanu.la]

>Number:         132852
>Category:       kern
>Synopsis:       LOR between sysctl and acpi_ibm
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Fri Mar 20 12:10:03 UTC 2009
>Closed-Date:
>Last-Modified:
>Originator:     User &
>Release:        FreeBSD 7.2-PRERELEASE i386
>Organization:
>Environment:
System: FreeBSD roo.7f000001.org 7.2-PRERELEASE FreeBSD 7.2-PRERELEASE #5: Thu Mar 19 12:52:23 CET 2009 root at roo.7f000001.org:/usr/obj/usr/src/sys/ROO i386

lock order reversal:
 1st 0xc08bc294 sysctl lock (sysctl lock) @ /usr/src/sys/kern/kern_sysctl.c:1501
 2nd 0xc0b1b184 ACPI IBM extras (ACPI IBM extras) @ /usr/src/sys/modules/acpi/acpi_ibm/../../../dev/acpi_support/acpi_ibm.c:484
KDB: stack backtrace:
db_trace_self_wrapper(c08345a1,c0b1b184,c0b19fe5,c0b19fe5,c0b19d90,...) at db_trace_self_wrapper+0x26
witness_checkorder(c0b1b184,9,c0b19d90,1e4,f4556b30,...) at witness_checkorder+0x555
_sx_xlock(c0b1b184,0,c0b19d90,1e4,c08bbcf0,...) at _sx_xlock+0x30
acpi_ibm_sysctl(c4e51180,c4e46080,0,f4556ba4,f4556ba4,...) at acpi_ibm_sysctl+0x3f
sysctl_root(f4556ba4,0,c083160f,5dd,c60d98c0,...) at sysctl_root+0xa2
userland_sysctl(c60d98c0,f4556c10,4,0,bfbfe4a4,...) at userland_sysctl+0xfb
__sysctl(c60d98c0,f4556cf8,18,c0835343,c0870a90,...) at __sysctl+0x9f
syscall(f4556d38) at syscall+0x18a
Xint0x80_syscall() at Xint0x80_syscall+0x20
--- syscall (202, FreeBSD ELF32, __sysctl), eip = 0x2815b1ff, esp = 0xbfbfdbac, ebp = 0xbfbfdbd8 ---
>Description:
>How-To-Repeat:
>Fix:
>Release-Note:
>Audit-Trail:
>Unformatted: