One was that ORC didn't know how to handle the ftrace callbacks in general
(which Josh fixed). The other was that ORC would just bail if it hit a
dynamically allocated trampoline. Which means all ftrace stack tracing that
happens from the function tracer would produce no results (that includes
killing the max stack size tracer). I added a check to the ORC unwinder to
see if the trampoline belonged to ftrace, and if it did, use the orc entry
of the static trampoline that was used to create the dynamic one (it would
be identical).
Finally, I noticed that the skip values of the stack tracing were out of
whack. I went through and fixed them up.
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Merge tag 'trace-v4.15-rc9' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing fixes from Steven Rostedt:
"With the new ORC unwinder, ftrace stack tracing became disfunctional.
One was that ORC didn't know how to handle the ftrace callbacks in
general (which Josh fixed).
The other was that ORC would just bail if it hit a dynamically
allocated trampoline. Which means all ftrace stack tracing that
happens from the function tracer would produce no results (that
includes killing the max stack size tracer). I added a check to the
ORC unwinder to see if the trampoline belonged to ftrace, and if it
did, use the orc entry of the static trampoline that was used to
create the dynamic one (it would be identical).
Finally, I noticed that the skip values of the stack tracing were out
of whack. I went through and fixed them up"
* tag 'trace-v4.15-rc9' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracing: Update stack trace skipping for ORC unwinder
ftrace, orc, x86: Handle ftrace dynamically allocated trampolines
x86/ftrace: Fix ORC unwinding from ftrace handlers
03fae44b41