Is it possible to get backtrace of kext without attaching with gdb as described at
if I have the panic log?
Somehow like this:
kextutil
Apple's tech note tn2063 describes analysing panics in detail. http://developer.apple.com/library/mac/ipad/#technotes/tn2063/_index.html
In addition, tn2118 describes analyzing kernel core dumps: http://developer.apple.com/library/mac/#technotes/tn2004/tn2118.html
You can get the kernel to dump on panic, then take that core dump and analyze it against the symbolicated kernel. You add your own kext's symbols to the kernel's with gdb's add-symbol-file command.