Re: [PATCH] selftests/ftrace: skip ftrace test if FTRACE was not enabled

[Steven Rostedt]

On Wed, 3 Jul 2019 12:09:53 +0900
Masami Hiramatsu <mhiramat@xxxxxxxxxx> wrote:

> > Would something like that work?  
> 
> For older kernel, I think we'd better try to mount debugfs first.

Sure, that's pretty trivial to do. Or what I was thinking, try it if it
fails:

 	if [ -z "$TRACING_DIR" ]; then
 	  save_err=$err_ret
 	  err_ret=$err_skip
	  if mount -t tracefs nodev /sys/kernel/tracing; then
 	    TRACING_DIR="/sys/kernel/tracing"
	  elif mount -t debugfs nodev /sys/kernel/debug; then
 	    TRACING_DIR="/sys/kernel/debug/tracing"
	  else
	    errexit "debugfs is not configured in this kernel"
	  fi
	  if [ ! -d "$TRACING_DIR" ]; then
	    errexit "ftrace is not configured in this kernel"
	  fi
 	  err_ret=$save_err
 	fi

-- Steve