9.0-RELEASE-p3 custom kernel build


I need to enable DTrace support on an old server with 9.0-RELEASE-p3(amd64) installed. So I have to rebuild kernel, but /usr/src is empty.

1. Do I need to download exactly 9.0-RELEASE-p3 source to build kernel or 9.0-RELEASE will be enough?
2. if I do need exactly 9.0-RELEASE-p3 source, then where can I get it?

Thank you.
It looks to me that if you pulled /base/releng/9.0 from SVN, that would get you the source for 9.0-RELEASE-p7 (-p3 plus a few more named/bind/openssl security fixes)