Patch-ID#  100265-01
Keywords: protection violation SIGBUS SIGSEGV
Synopsis: SunOS 4.1.1:writing to a PROT_READ area is giving SIGBUS not SIGSEGV
Date: 08/Apr/91

SunOS release: 4.1.1
 
Unbundled Product:
 
Topic: OS/Rationalizing Error Handling
 
BugIds fixed with this patch: 1039275

Architectures for which this patch is available: sun4 sun4c Sun3 and Sun3x

Problem Description:

	The bug exists because numerous attempts to fix error handling in
	various layers of the system resulted in an inconsistency.
	This would cause protection faults in a mapping range with 
	different per-page protections to return the wrong low-level
	error for protection violations.


INSTALL:


Rename the original files before installing the patches
 
# mv /sys/sun{3,3x,4,4c}/OBJ/seg_vn.o /sys/sun{3,3x,4,4c}/OBJ/seg_vn.o.FCS
 
Place the new " *.o" file in  /sys/sun{3,3x,4,4c}/OBJ
      for your correct " arch -k " type and SunOS release. 

# cp sun{3,3x,4,4c}/seg_vn.o /sys/sun{3,3x,4,4c}/OBJ/seg_vn.o

      Rebuild and install a new kernel and reboot.

Please refer to the system and networking administration manual on
building and installing a custom kernel.