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authorMark-PK Tsai <mark-pk.tsai@mediatek.com>2022-04-26 20:24:06 +0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2022-06-14 18:11:56 +0200
commit23b2163b887f1a997ea7378c8cb01d81ea8e94fb (patch)
tree70eeb61eff501ba356069158ffd10b37ce2bcd9b
parent48c6ee7d6c614f09b2c8553a95eefef6ecf196e0 (diff)
tracing: Avoid adding tracer option before update_tracer_options
[ Upstream commit ef9188bcc6ca1d8a2ad83e826b548e6820721061 ] 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> Signed-off-by: Sasha Levin <sashal@kernel.org>
-rw-r--r--kernel/trace/trace.c7
1 files changed, 7 insertions, 0 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index ce9165de019c..55da88f18342 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -5638,12 +5638,18 @@ 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);
}
@@ -8391,6 +8397,7 @@ 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);
}