memory inconsistencies with OpenAFS on FreeBSD

[Benjamin Kaduk]

Hi all,

I've been working to make the OpenAFS network filesystem client usable on 
FreeBSD; it's currently in a mostly-working state. 
( http://www.openafs.org/ ; I have a hackish packaging of it as a FreeBSD 
port at http://web.mit.edu/freebsd/openafs/openafs.shar .  Note that it is 
broken on recent -current since it it fails to register its syscall 
properly; this is fixed in git master pending an update to 
syscalls.master.)

Normal file operations from a shell work okay, I can write and 
edit a file with vi, etc.; copying /usr/src into and out of AFS proceeds 
nicely.
However, if I proceed to the standard lazy man's filesystem stress test, 
buildworld, things don't get very far:
>>> stage 1.1: legacy release compatibility shims
[...]
===> tools/build (obj,includes,depend,all,install)
[...]
cc -O2 -pipe -std=gnu99 
-I/afs/zone.mit.edu/user/kaduk/build/obj/afs/zone.mit.
edu/user/kaduk/build/tmp/legacy/usr/include -c 
/afs/zone.mit.edu/user/kaduk/buil
d/tools/build/dummy.c
building static egacy library
*** Signal 11

I also don't seem to be able to run executables from AFS:
freebuild# ./my_mmap test4
elf_load_section: truncated ELF file
Abort


Trying to dig a bit deeper and get a smaller test case, rwatson suggested 
that I look at mmap-ing a file and reading/writing from it. I wrote a 
small test program, and reading from the mmaped file works okay. However, 
writing to the mmap-ed file does not seem to take effect (though my test 
program does modify the target file on local disk).

(Also, when I do silly things like try to access unmapped memory which 
ought to generate a core dump, I get on the console:
freebuild kernel: Failed to write core file for process my_mmap (error 
14))

Where should I be looking to track down what's going on?

I note that we do provide our own getpages and putpages vops, and this 
code hasn't been particularly loved since the FreeBSD 4.x days.

Thanks for any suggestions,

Ben Kaduk