On Wed, 12 Aug 2020 16:58:54 -0400 Steven Rostedt <rostedt@xxxxxxxxxxx> wrote: > > This is marked as "Fixes" but is more of a clean up than a true fix. > > Backport if you want, but its not critical. > > A note to stable maintainers. I originally thought this was just a > clean up, but it was then found that it actually does fix a bug. I cut out the explanation in the email: > This addresses an issue we've seen with users trying to change > current_tracer when they happen to have rasdaemon installed. > rasdaemon uses the trace_pipe interface at runtime, which therefore > blocks changing the current tracer. But of course, unless > you know about rasdaemon internals, it isn't exactly an obvious > failure mode. > > Conflict in __remove_instance() was due to a change in reference counter > semantics introduced later in v5.5 via commit 288797871473 > "tracing: Adding new functions for kernel access to Ftrace instances". > Resolved by leaving the first test in the if statement as it was in v5.4. -- Steve
