[RFC PATCH 00/34] The rest of the x86_64-gnu port

[Sergey Bugaev]

On Mon, Apr 10, 2023 at 10:20 PM Samuel Thibault
<samuel.thibault@gnu.org> wrote:
>
> Sergey Bugaev, le dim. 19 mars 2023 18:09:43 +0300, a ecrit:
> > As for sigreturn specifically: I'm concerned about the possibility that
> > putting the register dump onto the user's stack (or at %rsp - 128, on x86_64)
> > may clobber the data trampoline.c puts there (unless an altstack is used),
> > including the very sigcontext.
>
> I guess we could make sure that the offset of ctx in stackframe is not
> hit by data written by sigreturn.c.

Right; it would be easiest to reserve enough space for the register
dump at the end of 'struct stackframe', i.e. right after the user's
stack.

Sergey