From 4114fbfd02f12d7a58cc4bd6fc36e0925266f9f7 Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Thu, 10 Sep 2020 21:39:07 +0900 Subject: tracing: Enable creating new instance early boot Enable creating new trace_array instance in early boot stage. If the instances directory is not created, postpone it until the tracefs is initialized. Link: https://lkml.kernel.org/r/159974154763.478751.6289753509587233103.stgit@devnote2 Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware) --- kernel/trace/trace.c | 53 +++++++++++++++++++++++++++++++++++++++++----------- 1 file changed, 42 insertions(+), 11 deletions(-) (limited to 'kernel/trace/trace.c') diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index c35fcd2f2529..6211a13b3327 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -8636,6 +8636,24 @@ struct trace_array *trace_array_find_get(const char *instance) return tr; } +static int trace_array_create_dir(struct trace_array *tr) +{ + int ret; + + tr->dir = tracefs_create_dir(tr->name, trace_instance_dir); + if (!tr->dir) + return -EINVAL; + + ret = event_trace_add_tracer(tr->dir, tr); + if (ret) + tracefs_remove(tr->dir); + + init_tracer_tracefs(tr, tr->dir); + __update_tracer_options(tr); + + return ret; +} + static struct trace_array *trace_array_create(const char *name) { struct trace_array *tr; @@ -8671,30 +8689,27 @@ static struct trace_array *trace_array_create(const char *name) if (allocate_trace_buffers(tr, trace_buf_size) < 0) goto out_free_tr; - tr->dir = tracefs_create_dir(name, trace_instance_dir); - if (!tr->dir) - goto out_free_tr; - - ret = event_trace_add_tracer(tr->dir, tr); - if (ret) { - tracefs_remove(tr->dir); + if (ftrace_allocate_ftrace_ops(tr) < 0) goto out_free_tr; - } ftrace_init_trace_array(tr); - init_tracer_tracefs(tr, tr->dir); init_trace_flags_index(tr); - __update_tracer_options(tr); + + if (trace_instance_dir) { + ret = trace_array_create_dir(tr); + if (ret) + goto out_free_tr; + } list_add(&tr->list, &ftrace_trace_arrays); tr->ref++; - return tr; out_free_tr: + ftrace_free_ftrace_ops(tr); free_trace_buffers(tr); free_cpumask_var(tr->tracing_cpumask); kfree(tr->name); @@ -8852,11 +8867,27 @@ static int instance_rmdir(const char *name) static __init void create_trace_instances(struct dentry *d_tracer) { + struct trace_array *tr; + trace_instance_dir = tracefs_create_instance_dir("instances", d_tracer, instance_mkdir, instance_rmdir); if (MEM_FAIL(!trace_instance_dir, "Failed to create instances directory\n")) return; + + mutex_lock(&event_mutex); + mutex_lock(&trace_types_lock); + + list_for_each_entry(tr, &ftrace_trace_arrays, list) { + if (!tr->name) + continue; + if (MEM_FAIL(trace_array_create_dir(tr) < 0, + "Failed to create instance directory\n")) + break; + } + + mutex_unlock(&trace_types_lock); + mutex_unlock(&event_mutex); } static void -- cgit v1.2.3-59-g8ed1b