Re: Revamp sniffer; Was: [obish?sym;rfa:doc] Wire up vsyscall

[Andrew Cagney <cagney@gnu.org>]

> If I understood your description correctly, the source of the current
> problem scenario is that glibc supplies CFI for the trampoline code
> (__restore_rt), but that CFI is not written to match how the peculiar frame
> will look.  So, glibc could change its CFI to use the same hack that the
> x86 kernel CFI uses for the analogous code, or it could omit that CFI
> entirely and expect gdb to recognize the name and/or instruction sequence.
> 
> My inclination is to omit the CFI because that's how it is on x86 in the
> analogous case.  (If in future x86-64 has kernel-supplied trampoline code,
> we expect it will be in the form of a vsyscall DSO that supplies CFI via
> existing glibc support, as on x86.  In that case, the CFI will use the same
> sort of hack as the x86 CFI does.)  Would that make things better?

Ah!  I guess it would help.  GDB will still need to do something more 
immediate though.

Andrew