Re: [PATCH v2 7/9] gdb: Provide gdbarch hook to distinguish shadow stack backtrace elements.

[Thiago Jung Bauermann <thiago.bauermann@linaro.org>]

Christina Schimpe <christina.schimpe@intel.com> writes:

> index 1f24a3a6d72..d39cba6e016 100644
> --- a/gdb/gdbarch_components.py
> +++ b/gdb/gdbarch_components.py
> @@ -2911,3 +2911,24 @@ In case shadow stack is not enabled for the current thread, return -1.
>      ],
>      predicate=True,
>  )
> +
> +Method(
> +    comment="""
> +There can be elements on the shadow stack which are not return addresses.
> +This happens for example on x86 with CET in case of signals.
> +If an architecture implements the command options 'backtrace -shadow' and
> +the shadow stack can contain elements which are not return addresses, this
> +function has to be provided.
> +
> +Return true, if FRAME does not contain a return address in FRAME->VALUE
> +but another valid value for the architecture's shadow stack.  In this case,
> +also the string frame_type has to be configured to display the type in the
> +shadow stack backtrace.
> +""",
> +    type="bool",
> +    name="is_no_return_shadow_stack_address",
> +    params=[
> +        ("const shadow_stack_frame_info &", "frame"),
> +        ("std::string &", "frame_type")],
> +    predicate=True,
> +)

Small nit: here the Black code formatter also makes a change:

     name="is_no_return_shadow_stack_address",
     params=[
         ("const shadow_stack_frame_info &", "frame"),
-        ("std::string &", "frame_type")],
+        ("std::string &", "frame_type"),
+    ],
     predicate=True,
 )

I also like Tom's idea of using a std::optional<std::string> for frame_type,
but regardless of whether you decide to adopt it:

Reviewed-by: Thiago Jung Bauermann <thiago.bauermann@linaro.org>

-- 
Thiago