RE: [PATCH 11/12] gdb, gdbarch: Introduce gdbarch method to get the shadow stack pointer.

["Schimpe, Christina" <christina.schimpe@intel.com>]

> -----Original Message-----
> From: Schimpe, Christina
> Sent: Sunday, February 16, 2025 11:45 AM
> To: Thiago Jung Bauermann <thiago.bauermann@linaro.org>
> Cc: gdb-patches@sourceware.org
> Subject: RE: [PATCH 11/12] gdb, gdbarch: Introduce gdbarch method to get
> the shadow stack pointer.
> 
> > -----Original Message-----
> > From: Thiago Jung Bauermann <thiago.bauermann@linaro.org>
> > Sent: Saturday, February 15, 2025 4:45 AM
> > To: Schimpe, Christina <christina.schimpe@intel.com>
> > Cc: gdb-patches@sourceware.org
> > Subject: Re: [PATCH 11/12] gdb, gdbarch: Introduce gdbarch method to
> > get the shadow stack pointer.
> >
> > Hello Christina,
> >
> > Thiago Jung Bauermann <thiago.bauermann@linaro.org> writes:
> >
> > > "Schimpe, Christina" <christina.schimpe@intel.com> writes:
> > >
> > >> Would something like that be acceptable as well?
> > >>
> > >> Method(
> > >>       comment="""
> > >> If possible, return the shadow stack pointer. On some
> > >> architectures, the shadow stack pointer is available even if the
> > >> feature is disabled.  To return the shadow stack enablement state
> > >> configure
> > SHADOW_STACK_ENABLED.
> > >>   """,
> > >> type="std::optional<CORE_ADDR>",
> > >> name="get_shadow_stack_pointer",
> > >> params=[("bool &", "shadow_stack_enabled")],
> > >> predefault="default_get_shadow_stack_pointer",
> > >> invalid=False,
> > >> )
> > >
> > > Yes, this looks good.
> >
> > I was rebasing my Guarded Control Stack code on top of this series,
> > and noticed that I will need to access the thread's regcache for the
> > aarch64 implementation of this gdbarch method. Then I noticed that the
> > x86_64 version also needs it, and calls "get_thread_regcache
> (inferior_thread ())".
> > It would be better to pass the regcache as an argument instead.
> 
> Hi Thiago,
> 
> Do you mean instead or in addition?
> I thought you also need the parameter ("bool &", "shadow_stack_enabled").
> 
> Christina


Hi Thiago,

Since you wrote instead I now have the regcache argument only in the v2 of this series.
https://sourceware.org/pipermail/gdb-patches/2025-February/215650.html
Please let me know if you see any problems with that.

Christina
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