On Fri, Aug 10, 2018 at 06:03:11PM +0200, Torsten Duwe wrote:

This is more an RFC in the original sense: is this basically
the correct approach? (as I had to tweak the API a bit).

In particular the code does not detect interrupts and exception
frames, and does not yet check whether the code address is valid.
The latter check would also have to be omitted for the latest frame
on other tasks' stacks. This would require some more tweaking.

unwind_frame() now reports whether we had to stop normally or due to
an error condition; walk_stackframe() will pass that info.
__save_stack_trace() is used for a start to check the validity of a
frame; maybe save_stack_trace_tsk_reliable() will need its own callback.

Any comments welcome.

Signed-off-by: Torsten Duwe <redacted>

Before we do this we'll need the same analysis we did for ppc64le to
figure out if objtool is needed.

-- 
Josh