[OpenMP][OMPT] Use global thread id for `codeptr_ra` in `end_critical` (#169826)
When a critical construct has finished, it will trigger a
critical-released event. If a tool is attached, and the `mutex_released`
callback was registered, the tool with receive an event containing the
`codeptr_ra`, the return address of the callback invocation.
All the way back in 82e94a593433f36734e2d34898d353a2ecb65b8b, this
`codeptr_ra` was implemented by calling `__ompt_load_return_address`
with a fixed global thread id of `0`. However, this approach results in
a race-condition, and can yield incorrect results to the tool.
`__ompt_load_return_address(0)` points to the current return address of
the thread 0 in `__kmp_threads`. This thread may already execute some
other construct. A tool might therefore receive the return address of
e.g. some `libomp` internals, or other parts of the user code.
Additionally, a call to `__ompt_load_return_address` resets the
`th.ompt_thread_info.return_address` to `NULL`, therefore also affecting
the return address of thread 0. Another dispatched event, e.g.
parallel-begin might therefore not transfer any `codeptr_ra`.
To fix this, replace the fixed thread id by the `global_tid`, which is
stored just before dispatching the `mutex_released` callback.
Signed-off-by: Jan André Reuter <j.reuter@fz-juelich.de>
llvm-project
94232f9f - [OpenMP][OMPT] Use global thread id for `codeptr_ra` in `end_critical` (#169826)
