dtracing unlink

[Thomas Klausner <wiz%NetBSD.org@localhost>]

Hi!

I'm trying to find out what a program does, and found it does a lot of
unlink syscalls, so I wanted to see what it unlinks.

I tried

# dtrace -n syscall::unlink:entry'/pid == 27647/{ self->file = arg0;  }' -n syscall::unlink:return'{ trace(copyinstr(self->file)); self->file = 0; }'

but this just gives me lots of

dtrace: error on enabled probe ID 2 (ID 405: syscall::unlink:return): invalid address (0x79c4586577ce) in action #1 at DIF offset 12
: No such file or directory

(yes, including that weird newline in the middle).

What's the proper way to do this?

Thanks,
 Thomas