On Fri, May 30, 2014 at 8:25 AM, H. Peter Anvin <h...@zytor.com> wrote: > > If we removed struct thread_info from the stack allocation then one > could do a guard page below the stack. Of course, we'd have to use IST > for #PF in that case, which makes it a non-production option.
We could just have the guard page in between the stack and the thread_info, take a double fault, and then just map it back in on double fault. That would give us 8kB of "normal" stack, with a very loud fault - and then an extra 7kB or so of stack (whatever the size of thread-info is) - after the first time it traps. That said, it's still likely a non-production option due to the page table games we'd have to play at fork/clone time. Linus -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/