* Steven Rostedt <rostedt@xxxxxxxxxxx> wrote: > This bit me in the butt. > > I couldn't understand why my init app was segfaulting, with a kernel > address, but a user RIP and RSP. Well, the RIP I think was bogus, but > the kernel address was always the start of "mcount". Looking deeper, > I printed out what was in the RSP (even though it was a user stack). > It ended up showing me that the calling address was from the VDSO > area. Looking even further, I found the offending culprit, which was > vread_hpet. > > Looking at the assembly dump, I saw the vread_hpet was calling mcount, > but I could not see it in the code. Nor could I see it in hpet.i (-E > option of compiling). > > Well, I guess Ingo is a magician when it comes to compiler tricks, and > has the mcount being called by "every!!" function, unless you add the > "notrace" option. > > This patch adds the notrace to vsyscall_fn, so that we don't have user > land apps calling mcount and crashing! doh - applied. Thanks! Ingo - To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
