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| author | Masami Hiramatsu <mhiramat@kernel.org> | 2020-09-24 19:40:08 +0300 |
|---|---|---|
| committer | Steven Rostedt (VMware) <rostedt@goodmis.org> | 2020-09-25 22:36:03 +0300 |
| commit | 720dee53ad8dfd528941fbbc264574601b04488a (patch) | |
| tree | 962f0ceeb9f7d09ca5d609acec69388431312946 /kernel/trace/trace_events.c | |
| parent | fd264ce96c382bc2e36eb1f49ac45c5980650244 (diff) | |
| download | linux-720dee53ad8dfd528941fbbc264574601b04488a.tar.xz | |
tracing/boot: Initialize per-instance event list in early boot
Initialize per-instance event list in early boot time (before
initializing instance directory on tracefs). This fixes boot-time
tracing to correctly handle the boot-time per-instance settings.
Link: https://lkml.kernel.org/r/160096560826.182763.17110991546046128881.stgit@devnote2
Fixes: 4114fbfd02f1 ("tracing: Enable creating new instance early boot")
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Diffstat (limited to 'kernel/trace/trace_events.c')
| -rw-r--r-- | kernel/trace/trace_events.c | 30 |
1 files changed, 16 insertions, 14 deletions
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index 42c0e7df6e70..851ab37058dd 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -3131,14 +3131,13 @@ static inline int register_event_cmds(void) { return 0; } #endif /* CONFIG_DYNAMIC_FTRACE */ /* - * The top level array has already had its trace_event_file - * descriptors created in order to allow for early events to - * be recorded. This function is called after the tracefs has been - * initialized, and we now have to create the files associated - * to the events. + * The top level array and trace arrays created by boot-time tracing + * have already had its trace_event_file descriptors created in order + * to allow for early events to be recorded. + * This function is called after the tracefs has been initialized, + * and we now have to create the files associated to the events. */ -static __init void -__trace_early_add_event_dirs(struct trace_array *tr) +static void __trace_early_add_event_dirs(struct trace_array *tr) { struct trace_event_file *file; int ret; @@ -3153,13 +3152,12 @@ __trace_early_add_event_dirs(struct trace_array *tr) } /* - * For early boot up, the top trace array requires to have - * a list of events that can be enabled. This must be done before - * the filesystem is set up in order to allow events to be traced - * early. + * For early boot up, the top trace array and the trace arrays created + * by boot-time tracing require to have a list of events that can be + * enabled. This must be done before the filesystem is set up in order + * to allow events to be traced early. */ -static __init void -__trace_early_add_events(struct trace_array *tr) +void __trace_early_add_events(struct trace_array *tr) { struct trace_event_call *call; int ret; @@ -3290,7 +3288,11 @@ int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr) goto out; down_write(&trace_event_sem); - __trace_add_event_dirs(tr); + /* If tr already has the event list, it is initialized in early boot. */ + if (unlikely(!list_empty(&tr->events))) + __trace_early_add_event_dirs(tr); + else + __trace_add_event_dirs(tr); up_write(&trace_event_sem); out: |