On 14/12/16 10:01, Segher Boessenkool wrote: > On Wed, Dec 14, 2016 at 09:49:32AM +0000, Andrew Haley wrote: >> On 13/12/16 18:15, Segher Boessenkool wrote: >>> Clobbering "memory" does not work here. Clobbering "rsp" however seems >>> to work. But, "seems to", I don't think there is a guarantee anywhere. >>> Clobbering the stack pointer forces the use of the frame pointer, but is >>> that guaranteed even? >> >> No, I think we shouldn't do that. If it's necessary to save things on >> the stack all we need to do is to avoid the red zone. That really isn't >> hard. > > That was a workaround for doing this with released compiler versions, > like e.g. anything you build current glibc with. But so is my suggestion, and it's much safer IMO. Andrew.
