Unix Articles & FAQ

Nothing is wrong with the machine. This happens when programs illegally cast types or make various other type-unsafe assumptions. Unlike the x86 and vax, risc processors require data items to be aligned. The compilers do this automatically, but some programs are so badly written that they override the compiler's choices and force the compiler to accept type-unsafe constructs.

The NetBSD kernel will fix these up on the fly, though it may slow your application down. To fix each unaligned access fault requires:

Using sysctl(8), the action can be tuned to one of:

The default action is equivalent to:

	<?php
#
?> <?php
sysctl -w machdep.unaligned_print=1
?>
	<?php
#
?> <?php
sysctl -w machdep.unaligned_fix=1
?>
	<?php
#
?> <?php
sysctl -w machdep.unaligned_sigbus=0
?>

An unaligned access performed by the kernel will always cause a panic.