kern/46592: lib/libc/sys/t_mmap cause kernel panic

[bouyer%antioche.eu.org@localhost]

>Number:         46592
>Category:       kern
>Synopsis:       lib/libc/sys/t_mmap cause kernel panic
>Confidential:   no
>Severity:       serious
>Priority:       high
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Tue Jun 12 10:05:00 +0000 2012
>Originator:     Manuel Bouyer
>Release:        NetBSD 6.99.7
>Organization:
>Environment:
System: NetBSD anita 6.99.7 NetBSD 6.99.7 (XEN3PAE_DOMU) #0: Sat Jun  9 
23:29:25 UTC 2012 
builds%b7.netbsd.org@localhost:/home/builds/ab/HEAD/amd64/201206092140Z-obj/home/builds/ab/HEAD/src/sys/arch/amd64/compile/XEN3_DOMU
 amd64
Architecture: amd64 (but also seen with i386)
Machine: amd64
>Description:
        As shown in automated run reports at:
        http://www-soc.lip6.fr/~bouyer/NetBSD-tests/xen/HEAD/
        amd64 and i386 kernels have been panicing on a t_mmap test for some
        time.
lib/libc/sys/t_mmap (332/519): 8 test cases
    mmap_block: panic: kernel diagnostic assertion "vp == 
vp->v_specnode->sn_dev->sd_bdevvp" failed: file 
"/home/builds/ab/HEAD/src/sys/miscfs/specfs/spec_vnops.c", line 891 
cpu1: Begin traceback...
kern_assert() at netbsd:kern_assert+0xae
spec_strategy() at netbsd:spec_strategy+0x97
VOP_STRATEGY() at netbsd:VOP_STRATEGY+0x33
genfs_getpages() at netbsd:genfs_getpages+0x1161
VOP_GETPAGES() at netbsd:VOP_GETPAGES+0x4f
uvn_get() at netbsd:uvn_get+0x50
uvm_fault_internal() at netbsd:uvm_fault_internal+0xcab
trap() at netbsd:trap+0x4e4
>How-To-Repeat:

        run anita test against a HEAD build.
>Fix: