Okay, new results. The 05 March and 12 March patches booted and worked great!
Today, with the 15 March patches and IDENTICAL config flags, I'm back at the error I mentioned above.
Here's a picture:https://drive.google.com/file/d/0B7y3E9 ... cxQjg/view
I did not update the userland before booting into the new kernel. I did the day before, but again, the 12 March patchset booted after that update. I tried updating after the new kernel was installed (back in the vanilla kernel) but that didn't help. I tried three builds yesterday, none worked, even one with a known-good config.
I'm back to scratching my head.
I hit a bug with chrome recently because my /tmp is mounted noexec. Would nosuid,nodev,noexec on either /tmp or /var impact the grsec kernel differently than the vanilla kernel?