[PATCH bpf] fprobe, samples: Add module parameter descriptions

["Masami Hiramatsu (Google)" <mhiramat@xxxxxxxxxx>]

From: Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx>

Add module parameter descriptions for the fprobe_example module.

Signed-off-by: Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx>
---
 samples/fprobe/fprobe_example.c |    7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/samples/fprobe/fprobe_example.c b/samples/fprobe/fprobe_example.c
index 01ee6c8c8382..18b1e5c4b431 100644
--- a/samples/fprobe/fprobe_example.c
+++ b/samples/fprobe/fprobe_example.c
@@ -25,12 +25,19 @@ static unsigned long nhit;
 
 static char symbol[MAX_SYMBOL_LEN] = "kernel_clone";
 module_param_string(symbol, symbol, sizeof(symbol), 0644);
+MODULE_PARM_DESC(symbol, "Probed symbol(s), given by comma separated symbols or a wildcard pattern.");
+
 static char nosymbol[MAX_SYMBOL_LEN] = "";
 module_param_string(nosymbol, nosymbol, sizeof(nosymbol), 0644);
+MODULE_PARM_DESC(nosymbol, "Not-probed symbols, given by a wildcard pattern.");
+
 static bool stackdump = true;
 module_param(stackdump, bool, 0644);
+MODULE_PARM_DESC(stackdump, "Enable stackdump.");
+
 static bool use_trace = false;
 module_param(use_trace, bool, 0644);
+MODULE_PARM_DESC(use_trace, "Use trace_printk instead of printk. This is only for debugging.");
 
 static void show_backtrace(void)
 {