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| author | Tom Zanussi <zanussi@kernel.org> | 2020-01-29 19:59:21 +0100 |
|---|---|---|
| committer | Steven Rostedt (VMware) <rostedt@goodmis.org> | 2020-01-30 15:46:27 +0100 |
| commit | 89c95fcef1942415e0f20d8c82e6e36ff8eeca9c (patch) | |
| tree | 5c7ff66ce0f2250652c7cbcea3e5e46128c92a4e /kernel/trace | |
| parent | trigger_next should increase position index (diff) | |
| download | linux-89c95fcef1942415e0f20d8c82e6e36ff8eeca9c.tar.xz linux-89c95fcef1942415e0f20d8c82e6e36ff8eeca9c.zip | |
tracing: Add trace_array_find/_get() to find instance trace arrays
Add a new trace_array_find() function that can be used to find a trace
array given the instance name, and replace existing code that does the
same thing with it. Also add trace_array_find_get() which does the
same but returns the trace array after upping its refcount.
Also make both available for use outside of trace.c.
Link: http://lkml.kernel.org/r/cb68528c975eba95bee4561ac67dd1499423b2e5.1580323897.git.zanussi@kernel.org
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Diffstat (limited to 'kernel/trace')
| -rw-r--r-- | kernel/trace/trace.c | 43 | ||||
| -rw-r--r-- | kernel/trace/trace.h | 2 |
2 files changed, 35 insertions, 10 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 8d144fd94aa8..183b031a3828 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -8499,6 +8499,34 @@ static void update_tracer_options(struct trace_array *tr) mutex_unlock(&trace_types_lock); } +/* Must have trace_types_lock held */ +struct trace_array *trace_array_find(const char *instance) +{ + struct trace_array *tr, *found = NULL; + + list_for_each_entry(tr, &ftrace_trace_arrays, list) { + if (tr->name && strcmp(tr->name, instance) == 0) { + found = tr; + break; + } + } + + return found; +} + +struct trace_array *trace_array_find_get(const char *instance) +{ + struct trace_array *tr; + + mutex_lock(&trace_types_lock); + tr = trace_array_find(instance); + if (tr) + tr->ref++; + mutex_unlock(&trace_types_lock); + + return tr; +} + static struct trace_array *trace_array_create(const char *name) { struct trace_array *tr; @@ -8575,10 +8603,8 @@ static int instance_mkdir(const char *name) mutex_lock(&trace_types_lock); ret = -EEXIST; - list_for_each_entry(tr, &ftrace_trace_arrays, list) { - if (tr->name && strcmp(tr->name, name) == 0) - goto out_unlock; - } + if (trace_array_find(name)) + goto out_unlock; tr = trace_array_create(name); @@ -8706,12 +8732,9 @@ static int instance_rmdir(const char *name) mutex_lock(&trace_types_lock); ret = -ENODEV; - list_for_each_entry(tr, &ftrace_trace_arrays, list) { - if (tr->name && strcmp(tr->name, name) == 0) { - ret = __remove_instance(tr); - break; - } - } + tr = trace_array_find(name); + if (tr) + ret = __remove_instance(tr); mutex_unlock(&trace_types_lock); mutex_unlock(&event_mutex); diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index b3075b637d14..f5480a2aa334 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -358,6 +358,8 @@ extern struct mutex trace_types_lock; extern int trace_array_get(struct trace_array *tr); extern int tracing_check_open_get_tr(struct trace_array *tr); +extern struct trace_array *trace_array_find(const char *instance); +extern struct trace_array *trace_array_find_get(const char *instance); extern int tracing_set_time_stamp_abs(struct trace_array *tr, bool abs); extern int tracing_set_clock(struct trace_array *tr, const char *clockstr); |