Messages in this thread | | | Date | Mon, 15 Jan 2018 12:04:05 -0600 | From | Josh Poimboeuf <> | Subject | Re: [PATCH 2/4] objtool: Implement jump_assert for _static_cpu_has() |
| |
On Mon, Jan 15, 2018 at 05:44:30PM +0100, Peter Zijlstra wrote: > Unlike the jump_label bits, static_cpu_has is implemented with > alternatives. Sadly it doesn't readily distinguish itself from any > other alternatives. > > Use a heuristic to guess at it :/ > > But like jump_labels, make static_cpu_has set br_static on the > instructions after the static branch such that we can assert on it.
This seems a bit heavy handed and fragile, though maybe it is the best way. Still I wonder if there's a better way to do it.
Some quick ideas:
a) Somehow use __jump_table in the _static_cpu_has() macro?
b) Add another special annotation to tell objtool where _static_cpu_has() locations are?
May need to ruminate on this one a bit...
-- Josh
| |