Messages in this thread | | | Subject | Re: [PATCH v3 16/51] x86/32: put real return address on stack in entry code | From | "H. Peter Anvin" <> | Date | Mon, 15 Aug 2016 12:22:33 -0700 |
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On 08/15/16 11:25, Josh Poimboeuf wrote: > On Mon, Aug 15, 2016 at 11:04:42AM -0700, H. Peter Anvin wrote: >> On 08/15/16 08:09, Josh Poimboeuf wrote: >>> On Sun, Aug 14, 2016 at 12:31:47AM -0700, Andy Lutomirski wrote: >>>> On Fri, Aug 12, 2016 at 7:28 AM, Josh Poimboeuf <jpoimboe@redhat.com> wrote: >>>>> This standardizes the stacks of idle tasks to be consistent with other >>>>> tasks on 32-bit. >>>> >>>> It might be nice to stick a ud2 or 1: hlt; jmp 1b or similar >>>> afterwards to make it clear that initial_code can't return. >>> >>> Yeah, I'll do something like that. >>> >> >> "Standardizing the stack" how? A zero on the stack terminates the stack >> trace. > > Instead of zero, user tasks have a real return address at that spot. > This makes idle tasks consistent with that, so we have a well defined > "end of stack". Also it makes the stack trace more useful since it > shows what entry code was involved in calling into C. >
So how is the stack terminated, and does things like kdb and kgdb need modifications? Or is there now a stack termination above the struct pt_regs?
-hpa
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