>Number:         11704
>Category:       kern
>Synopsis:       "panic: ubc_fault: concurrent writes vp 0xc57d8e78" via nfs_write
>Confidential:   no
>Severity:       serious
>Priority:       high
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Tue Dec 12 05:37:00 PST 2000
>Closed-Date:
>Last-Modified:
>Originator:     Martin J. Laubach
>Release:        1.5N 12-12-2000
>Organization:
>Environment:
	
System: NetBSD asparagus 1.5N NetBSD 1.5N (ASPARAGUS) #0: Tue Dec 12 13:43:48 CET 2000 mjl@asparagus:/home/temp/devel/cvs/src/sys/arch/i386/compile/ASPARAGUS i386
Architecture: i386
Machine: i386


>Description:
  While rebuilding userland, that machine panicked with

	panic: ubc_fault: concurrent writes vp 0xc57d8e78

  The traceback is as follows>

panic: ubc_fault: concurrent writes vp %p
#0  0xc023a960 in hexdigits.35 ()
(gdb) where
#0  0xc023a960 in hexdigits.35 ()
#1  0x2867000 in ?? ()
#2  0xc01e3d43 in cpu_reboot (howto=256, bootstr=0x0)
    at ../../../../arch/i386/i386/machdep.c:1375
#3  0xc0137803 in panic () at ../../../../kern/subr_prf.c:240
#4  0xc01d21df in ubc_alloc (uobj=0xc57d8e78, offset=271, lenp=0xc590ce1c, 
    flags=1) at ../../../../uvm/uvm_bio.c:427
#5  0xc0183ae9 in nfs_write (v=0xc590cec0) at ../../../../nfs/nfs_bio.c:617
#6  0xc0156fd4 in vn_write (fp=0xc5883514, offset=0xc5883530, uio=0xc590cf0c, 
    cred=0xc04a0300, flags=1) at ../../../../sys/vnode_if.h:386
#7  0xc013950c in dofilewrite (p=0xc58e21b0, fd=2, fp=0xc5883514, 
    buf=0xbfbfc9c0, nbyte=75, offset=0xc5883530, flags=1, retval=0xc590cf80)
    at ../../../../kern/sys_generic.c:360
#8  0xc013946f in sys_write (p=0xc58e21b0, v=0xc590cf88, retval=0xc590cf80)
    at ../../../../kern/sys_generic.c:311
#9  0xc01e8a81 in syscall_plain (frame={tf_es = 31, tf_ds = 31, 
      tf_edi = -1077950016, tf_esi = 134703024, tf_ebp = -1077950088, 
      tf_ebx = 1210389628, tf_edx = -1077948992, tf_ecx = 0, tf_eax = 4, 
      tf_trapno = 3, tf_err = 2, tf_eip = 1210345107, tf_cs = 23, 
      tf_eflags = 518, tf_esp = -1077950112, tf_ss = 31, tf_vm86_es = 0, 
      tf_vm86_ds = 0, tf_vm86_fs = 0, tf_vm86_gs = 0})
    at ../../../../arch/i386/i386/syscall.c:139
#10 0xc0100d5e in syscall1 ()
can not access 0xbfbfc978, invalid translation (invalid PDE)
can not access 0xbfbfc978, invalid translation (invalid PDE)
Cannot access memory at address 0xbfbfc978.

>How-To-Repeat:
>Fix:
>Release-Note:
>Audit-Trail:
>Unformatted: