[Crash-utility] Broken backtrace with nested NMIs

Hi all, as discovered by my colleagues, the backtrace code has been broken for NMI stacks since kernel commit 3f3c8b8c4b2a34776c3470142a7c8baafcda6eb0 (Linux 3.3). I am working on a fix, but it's tricky to get all cases right. For example, the copied and saved register locations were swapped with kernel commit 28696f434fef0efa97534b59986ad33b9c4df7f8, so we have at least 3 possible layouts: 1. pre-3.3 (no nesting) 2. 3.3 to 3.8 (saved, then copied) 3. 3.8+ (copied, then saved) I'm writing this mail to tell you I'm working on it. I don't have a fix (yet), but want to avoid duplicate efforts if more people start working on this. Petr T