On Mon, Apr 10, 2023 at 10:20 PM Samuel Thibault <samuel.thiba...@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
