Re: [patch] allow switching stacks

Jim Blandy
2004-04-12T21:05:16Z

Daniel Jacobowitz <drow@false.org> writes:
> There's no way in unwind information to annotate a non-call frame,
> which is the common relevant property for signal frames, dummy frames,
> and interrupt handler frames. Should there be?

There isn't? For signal frames, for example, the registers are all
saved in the ucontext_t, on the signal handler's stack. Can't we
hand-build Dwarf 2 CFI that points into the ucontext_t?

On IA-32 machines, the processor saves %eflags, %eip, and %cs, and
possibly %esp and %ss, and it's up to the handler code to save
whatever else needs preserving. We could hand-build Dwarf 2 CFI for
that, too.