On Wed, Aug 28, 2019 at 12:30:41PM +0900, Masami Hiramatsu wrote: > > kprobes can be created in the tracefs filesystem (which is separate from > > debugfs, tracefs just gets automatically mounted > > in /sys/kernel/debug/tracing when debugfs is mounted) from the > > kprobe_events file. /sys/kernel/tracing is just the tracefs > > directory without debugfs, and was created specifically to allow > > tracing to be access without opening up the can of worms in debugfs. > > I like the CAP_TRACING for tracefs. Can we make the tracefs itself > check the CAP_TRACING and call file_ops? or each tracefs file-ops > handlers must check it? Thanks for the feedback. I'll hack a prototype of CAP_TRACING for perf bits that I understand and you folks will be able to use it in ftrace when initial support lands. imo the question above is an implementation detail that you can resolve later. I see it as a followup to initial CAP_TRACING drop.