diff options
| author | Mark-PK Tsai <mark-pk.tsai@mediatek.com> | 2022-04-26 14:24:06 +0200 |
|---|---|---|
| committer | Steven Rostedt (Google) <rostedt@goodmis.org> | 2022-04-26 23:58:52 +0200 |
| commit | ef9188bcc6ca1d8a2ad83e826b548e6820721061 (patch) | |
| tree | 4504d88904fb9e54239b753fdd344bbcd6310c8e | |
| parent | ring-buffer: Simplify if-if to if-else (diff) | |
| download | linux-ef9188bcc6ca1d8a2ad83e826b548e6820721061.tar.xz linux-ef9188bcc6ca1d8a2ad83e826b548e6820721061.zip | |
tracing: Avoid adding tracer option before update_tracer_options
To prepare for support asynchronous tracer_init_tracefs initcall,
avoid calling create_trace_option_files before __update_tracer_options.
Otherwise, create_trace_option_files will show warning because
some tracers in trace_types list are already in tr->topts.
For example, hwlat_tracer call register_tracer in late_initcall,
and global_trace.dir is already created in tracing_init_dentry,
hwlat_tracer will be put into tr->topts.
Then if the __update_tracer_options is executed after hwlat_tracer
registered, create_trace_option_files find that hwlat_tracer is
already in tr->topts.
Link: https://lkml.kernel.org/r/20220426122407.17042-2-mark-pk.tsai@mediatek.com
Link: https://lore.kernel.org/lkml/20220322133339.GA32582@xsang-OptiPlex-9020/
Reported-by: kernel test robot <oliver.sang@intel.com>
Signed-off-by: Mark-PK Tsai <mark-pk.tsai@mediatek.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
| -rw-r--r-- | kernel/trace/trace.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 27bb486c3f97..7275173c55d0 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -6332,12 +6332,18 @@ static void tracing_set_nop(struct trace_array *tr) tr->current_trace = &nop_trace; } +static bool tracer_options_updated; + static void add_tracer_options(struct trace_array *tr, struct tracer *t) { /* Only enable if the directory has been created already. */ if (!tr->dir) return; + /* Only create trace option files after update_tracer_options finish */ + if (!tracer_options_updated) + return; + create_trace_option_files(tr, t); } @@ -9176,6 +9182,7 @@ static void __update_tracer_options(struct trace_array *tr) static void update_tracer_options(struct trace_array *tr) { mutex_lock(&trace_types_lock); + tracer_options_updated = true; __update_tracer_options(tr); mutex_unlock(&trace_types_lock); } |