Subject: Re: mips handling of SIGSEGV and SIGBUS.
To: None <thorpej@zembu.com>
From: Chris G. Demetriou <cgd@sibyte.com>
List: tech-kern
Date: 09/26/2000 13:49:42
Jason R Thorpe <thorpej@zembu.com> writes:
> The SVR4 ABI MIPS supplementary document specifies the signals to be
> delivered for various traps.  I don't know if anyone modified our code
> to follw that guide, but I agree with your conclusion, but would like
> to point out that SVR4 ABI compatibility might be an issue.  I'll dig
> my copy of that document and report back here.

I looked briefly at the document's table of contents, and didn't see
anything about signals, and i don't have time to look at the document
in depth so i did some testing of irix.  8-)

        unsigned int l[2];

        *(unsigned int *)(0) = 0;

		-> SIGSEGV

        *(unsigned int *)(1) = 0;

		-> SIGBUS

        *(unsigned int *)((int)0x80000000) = 0;

		-> SIGBUS

        *(unsigned int *)((int)0x80000001) = 0;

		-> SIGBUS

        *(unsigned int *)((char *)&l + 0)= 0;

		-> OK (as expected 8-)

        *(unsigned int *)((char *)&l + 1)= 0;

		-> SIGBUS


That's on an irix 6.4 (? that's what uname -r says, but i know nothing
about irix versioning anymore 8-) system.



chris