Subject: unaligned access's generating Bus error?
To: None <port-alpha@NetBSD.ORG>
From: Tim Rightnour <root@garbled.net>
List: port-alpha
Date: 06/20/1998 06:12:39
Well..  still at it.. this time the culprit is scheme.

build/build-usual-image . "`pwd`/scheme" 'scheme48.image' './scheme48vm' 
'build/initial.image'
pid 1066 (scheme48vm): unaligned access: va=0x12011e00c pc=0x12000256c
ra=0x120002158 op=stq
pid 1066 (scheme48vm): unaligned access: va=0x1211226fc pc=0x1200025b8
ra=0x120002158 op=stq
pid 1066 (scheme48vm): unaligned access: va=0x121122704 pc=0x1200025c0
ra=0x120002158 op=stq
Bus error - core dumped

Now.. I've seen these before..  I had this same problem compiling the icon pkg.
 Tons of unaligned accesses then suddenly wham.. sigsegv.  With that one, I
ended up 64bit cleaning it as best I could, and that fixed it right up.  No
more unaligns, no more coredumps.

I made this 64bit clean, to the best of my knowledge.. (there are some
uninitialized variables, would that cause this?)

what scared me, and prompted my little post here.. was this death spew from gdb:

(gdb) core scheme48vm.core 
Core was generated by `scheme48vm'.
Program terminated with signal 10, Bus error.
pid 1074 (gdb): unaligned access: va=0x120225e9a pc=0x12004d998 ra=0x12004cc34
op=stt
pid 1074 (gdb): unaligned access: va=0x120225ea2 pc=0x12004d998 ra=0x12004cc34
op=stt
pid 1074 (gdb): unaligned access: va=0x120225eaa pc=0x12004d998 ra=0x12004cc34
op=stt
<<< cutting out about 2 pages of unaligned access >>>
pid 1074 (gdb): unaligned access: va=0x120225f92 pc=0x12004d9ac ra=0x12004cc34
op=stq
Bus error (core dumped)

clunk. gdb dumps core.  What the heck is going on around here?  I suppose I can
live with pkg's bus erroring on me because of a UA, but wow.. gdb?  I have a
problem with that..

---
Tim Rightnour    -  root@garbled.net
http://www.zynetwc.com/~garbled/garbled.html