Merge tag 'trace-v6.5-rc6' of git://git./linux/kernel/git/trace/linux-trace
Pull tracing fixes from Steven Rostedt:
- Fix ring buffer being permanently disabled due to missed
record_disabled()
Changing the trace cpu mask will disable the ring buffers for the
CPUs no longer in the mask. But it fails to update the snapshot
buffer. If a snapshot takes place, the accounting for the ring buffer
being disabled is corrupted and this can lead to the ring buffer
being permanently disabled.
- Add test case for snapshot and cpu mask working together
- Fix memleak by the function graph tracer not getting closed properly.
The iterator is used to read the ring buffer. When it opens, it calls
the open function of a tracer, and when it is closed, it calls the
close iteration. While a trace is being read, it is still possible to
change the tracer.
If this happens between the function graph tracer and the wakeup
tracer (which uses function graph tracing), the tracers are not
closed properly during when the iterator sees the switch, and the
wakeup function did not initialize its private pointer to NULL, which
is used to know if the function graph tracer was the last tracer. It
could be fooled in thinking it is, but then on exit it does not call
the close function of the function graph tracer to clean up its data.
- Fix synthetic events on big endian machines, by introducing a union
that does the conversions properly.
- Fix synthetic events from printing out the number of elements in the
stacktrace when it shouldn't.
- Fix synthetic events stacktrace to not print a bogus value at the
end.
- Introduce a pipe_cpumask that prevents the trace_pipe files from
being opened by more than one task (file descriptor).
There was a race found where if splice is called, the iter->ent could
become stale and events could be missed. There's no point reading a
producer/consumer file by more than one task as they will corrupt
each other anyway. Add a cpumask that keeps track of the per_cpu
trace_pipe files as well as the global trace_pipe file that prevents
more than one open of a trace_pipe file that represents the same ring
buffer. This prevents the race from happening.
- Fix ftrace samples for arm64 to work with older compilers.
* tag 'trace-v6.5-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
samples: ftrace: Replace bti assembly with hint for older compiler
tracing: Introduce pipe_cpumask to avoid race on trace_pipes
tracing: Fix memleak due to race between current_tracer and trace
tracing/synthetic: Allocate one additional element for size
tracing/synthetic: Skip first entry for stack traces
tracing/synthetic: Use union instead of casts
selftests/ftrace: Add a basic testcase for snapshot
tracing: Fix cpu buffers unavailable due to 'record_disabled' missed