tracing/osnoise: Properly unhook events if start_per_cpu_kthreads() fails

If start_per_cpu_kthreads() called from osnoise_workload_start() returns
error, event hooks are left in broken state: unhook_irq_events() called
but unhook_thread_events() and unhook_softirq_events() not called, and
trace_osnoise_callback_enabled flag not cleared.

On the next tracer enable, hooks get not installed due to
trace_osnoise_callback_enabled flag.

And on the further tracer disable an attempt to remove non-installed
hooks happened, hitting a WARN_ON_ONCE() in tracepoint_remove_func().

Fix the error path by adding the missing part of cleanup.
While at this, introduce osnoise_unhook_events() to avoid code
duplication between this error path and normal tracer disable.

Link: https://lkml.kernel.org/r/[email protected]

Cc: [email protected]
Fixes: bce29ac9ce0b ("trace: Add osnoise tracer")
Acked-by: Daniel Bristot de Oliveira <[email protected]>
Signed-off-by: Nikita Yushchenko <[email protected]>
Signed-off-by: Steven Rostedt <[email protected]>

0 files changed, 0 insertions, 0 deletions