Patch-ID#  100279-01
Keywords: corrupted, streams, pointers, b_datap, block, message, msgdsize
Synopsis: SunOS 4.1.1: msgdsize, message block b_datap pointers are getting corrupted
Date: 29/April/91
 
SunOS release: 4.1, 4.1.1
 
Unbundled Product: 
 
Unbundled Release: 
 
Topic: Bad trap
 
BugId's fixed with this patch: 1058097

Architectures for which this patch is available: sun3, sun3x, sun4, sun4c

Patches which may conflict with this patch: 100189,100255,100233

Obsoleted by: SunOS 5.0

Problem Description:
  This problem has been seen on 4.1, 4.1.1 systems.
  The data fault will always occur in login.  The pc and backtrace are always the same. 
  The mblk_t (bp) is corrupted - bp->b_datap is set to 0
System panic is:
BAD TRAP
pid 1643, `ion': Data fault
kernel read fault at addr=0xc, pme=0x0
Sync Error Reg 80<INVALID>
pc=0xf8042c0c, sp=0xf8385ba0, psr=0x801ac0, context=0x2
g1-g7: 801ae1, f8385fb4, ffffff80, 50000, f8386000, 0, 0
Begin traceback... sp = f8385ba0

INSTALL: 

as root:
# mv /sys/sun{3,3x,4,4c}/OBJ/str_io.o /sys/{3,3x,4,4c}/OBJ/str_io.o.FCS
# cp sun{3,3x,4,4c}/{4.1,4.1.1}/str_io.o /sys/sun{3,3x,4,4c}/OBJ/str_io.o

rerun /etc/config on your kernel build file and make and install a new kernel.
Please refer to the system and networking administration manual for building and
installing a custom kernel.