On Mon, Jan 24, 2022 at 08:33:57AM +0300, Nikita Yushchenko wrote:
commit 0878355b51f5f26632e652c848a8e174bb02d22d upstream.
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/20220109153459.3701773-1-nikita.yushchenko@virtuoz...
Cc: stable@vger.kernel.org Fixes: bce29ac9ce0b ("trace: Add osnoise tracer") Acked-by: Daniel Bristot de Oliveira bristot@kernel.org Signed-off-by: Nikita Yushchenko nikita.yushchenko@virtuozzo.com Signed-off-by: Steven Rostedt rostedt@goodmis.org
kernel/trace/trace_osnoise.c | 20 ++++++++++++++++---- 1 file changed, 16 insertions(+), 4 deletions(-)
Now queued up, thanks.
greg k-h