Patch-ID# 100577-02
Keywords: swap instruction simulation  
Synopsis: SunOS 4.1.2: atomic swap instruction is failing on sun4c & sun4
Date: 28/Apr/92

SunOS release: 4.1.2 

Unbundled Product: 

Unbundled Release: 

Topic: atomic swap instruction failure on sun4 & sun4c with 4.1.2

BugId's fixed with this patch: 1087264

Architectures for which this patch is available: sun4c, sun4

Patches which may conflict with this patch: 

Obsoleted by: 

Files included with this patch: 

	sun4c/trap.o
	sun4c/trap.dbe.o
	sun4/trap.o
	sun4/trap.dbe.o

Problem Description: The SPARC assembler instruction 'swap' is simulated
			by the kernel on some machines. In 4.1.2 this
			code was broken, so the simulated swap fails.

Notice: If using DBE on the system be sure and use that version of the
	object module.

Install Instructions: mv /sys/`arch -k`/OBJ/trap.o /sys/`arch -k`/OBJ/trap.o.FCS
		      cp `arch -k`/trap.o /sys/`arch -k`/OBJ/trap.o

	Now link a new kernel and reboot.



ADDENDUM:
Version 2 adds support for sun4 architecture.