Trashed registers returning from kernel?

[Tim Kientzle]

On the BeagleBone, I'm seeing a similar crash in several different user land programs.  I suspect it's a kernel bug.

Symptom: program is killed with SIGSEGV.  Most of the registers contain values above 0xc0000000 (pointing into kernel space).

Theory:
 * Registers are not always getting correctly restored on a kernel->user transition.
 * SEGV is a consequence.

I can reproduce it semi-consistently by running "emacs existing-file" just after a reboot.  (But I'm pretty sure this is the same symptoms I've seen with several other programs, so I don't think it's a bug in emacs.)

Has anyone else seen this on an armv6 system?

Does anyone have suggestions for how to go about debugging this?

Suggestions appreciated.

Cheers,

Tim