Re: [PATCH 7/7] DWARF: add the config option

[Josh Poimboeuf]

On Sat, May 20, 2017 at 11:20:34AM -0500, Josh Poimboeuf wrote:
>    But then, if we're going that far, why not just have objtool reformat
>    the data into something much simpler?  It already has the knowledge
>    to do so.  Then we don't have to jump through all those hoops to
>    justify jumping through more hoops in the kernel (i.e., having a
>    complex DWARF state machine).  With a simple debuginfo format, the
>    kernel unwinder is simple enough that we don't need to validate its
>    functionality in a simulator.

I should clarify that it doesn't have to be objtool which does this.  It
could instead be a simple DWARF-to-undwarf conversion tool which runs
during the vmlinux linking stage.

Anyway we're both proposing simplifying the DWARF data into an
easier-to-parse format.  I think the question is whether we want that
simplification process to happen in the kernel (in the middle of a
kernel unwind operation), or at build time.

-- 
Josh