4.18-stable review patch. If anyone has any objections, please let me know.
------------------
From: Masami Hiramatsu mhiramat@kernel.org
commit 18858511fd8a877303cc34c06efa461b26a0e070 upstream.
Return -ENOENT error if there is no target synthetic event. This notices an operation failure to user as below;
# echo 'wakeup_latency u64 lat; pid_t pid;' > synthetic_events # echo '!wakeup' >> synthetic_events sh: write error: No such file or directory
Link: http://lkml.kernel.org/r/154013449986.25576.9487131386597290172.stgit@devbox
Acked-by: Tom Zanussi zanussi@linux.intel.com Tested-by: Tom Zanussi zanussi@linux.intel.com Cc: Shuah Khan shuah@kernel.org Cc: Rajvi Jingar rajvi.jingar@intel.com Cc: stable@vger.kernel.org Fixes: 4b147936fa50 ('tracing: Add support for 'synthetic' events') Signed-off-by: Masami Hiramatsu mhiramat@kernel.org Signed-off-by: Steven Rostedt (VMware) rostedt@goodmis.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- kernel/trace/trace_events_hist.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
--- a/kernel/trace/trace_events_hist.c +++ b/kernel/trace/trace_events_hist.c @@ -1072,8 +1072,10 @@ static int create_synth_event(int argc, event = NULL; ret = -EEXIST; goto out; - } else if (delete_event) + } else if (delete_event) { + ret = -ENOENT; goto out; + }
if (argc < 2) { ret = -EINVAL;