On Thu, May 12, 2016 at 08:48:35AM +0200, Ingo Molnar wrote: > I suppose the SGI/UV code is the only one using 7 arguments or more? Might make > sense to point that out in the changelog. First off, to everybody, sorry for the delayed responses. I've been AFK for a few days and forgot to set my vacation notice :( Yes, I believe that's it. I didn't do a full audit, but a quick glance at the other users of this call showed that nobody else appears to be using that many args. > Just curious, how did you find this bug? It's a pretty obscure one, of the > 'developer tears out hairs from frustruation' type ... Yes, this one was a real puzzle to figure out. Basically I just stepped through the assembly code from a known good point to see how we ended up where we did. I quite a bit of help from the vets around here, as well as from our simulator that I used to step through our early boot code to find the problem. The real hair pulling mostly came from trying to figure out *WHY* we were putting the return address in this seemingly random spot on the stack. After thoroughly re-reading assorted Intel (et. al.) docs about a hundred times, I was able to piece together what I thought was supposed to be going on here. The solution may be simple, but arriving there was anything but that :) - Alex -- To unsubscribe from this list: send the line "unsubscribe linux-efi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
