On Fri, Aug 12, 2016 at 7:28 AM, Josh Poimboeuf <jpoim...@redhat.com> wrote: > Thanks to all the recent x86 entry code refactoring, most tasks' kernel > stacks start at the same offset right above their saved pt_regs, > regardless of which syscall was used to enter the kernel. That creates > a nice convention which makes it straightforward to identify the end of > the stack, which can be useful for stack walking code which needs to > verify the stack is sane. > > However, the boot CPU's idle "swapper" task doesn't follow that > convention. Fix that by starting its stack at a sizeof(pt_regs) offset > from the end of the stack page. >
I think this is an improvement. If you want to be fancy, from memory it might be nice to poke -1 into the orig_ax slot, but this doesn't matter much. --Andy
