tracing: Use system_state in trace_printk_init_buffers()

The function trace_printk_init_buffers() is used to expand tha
trace_printk buffers when trace_printk() is used within the kernel or in
modules. On kernel boot up, it holds off from starting the sched switch
cmdline recorder, but will start it immediately when it is added by a
module.

Currently it uses a trick to see if the global_trace buffer has been
allocated or not to know if it was called by module load or not. But this
is more of a hack, and can not be used when this code is moved out of
trace.c. Instead simply look at the system_state and if it is running then
it is know that it could only be called by module load.

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: https://patch.msgid.link/20260208032450.660237094@kernel.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index f4ae80564615ec40ab34643d302467208d25320d..4066c33674e762fc4e35c78fcb54ea79fdb02af3 100644 (file)
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -3243,10 +3243,9 @@ void trace_printk_init_buffers(void)
        /*
         * trace_printk_init_buffers() can be called by modules.
         * If that happens, then we need to start cmdline recording
-        * directly here. If the global_trace.buffer is already
-        * allocated here, then this was called by module code.
+        * directly here.
         */
-       if (global_trace.array_buffer.buffer)
+       if (system_state == SYSTEM_RUNNING)
                tracing_start_cmdline_record();
 }
 EXPORT_SYMBOL_GPL(trace_printk_init_buffers);