5 ms·
I used crashme to discover a bug in the Broadcom Sibyte CPU that depended on branch prediction history.
by greglindahl 10y ago
I used crashme to discover a bug in the Broadcom Sibyte CPU that depended on branch prediction history.
- dingo_bat 10y agoI'd love to read details about your experience. Have you had a chance to write it up?
- greglindahl 10y agoI never wrote it up. The only weird thing about it was that unmodified crashme wouldn't run because of a prefetch bug in the silicon, plus there was a debugging trap that wasn't handled in the kernel. I added a trivial handler for the trap and pre-processed the randomly-generated crashme code to nop prefetches... 15 seconds later, I saw the hang.