docs: ftrace: Correct access mode

The documentation gives an example for opening trace marker with
write-only mode, but the flag WR_ONLY is not defined by glibc.

Use O_WRONLY to replace it.

Signed-off-by: Leo Yan <leo.yan@linaro.org>
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Link: https://lore.kernel.org/r/20221008083250.3160-1-leo.yan@linaro.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

diff --git a/Documentation/trace/ftrace.rst b/Documentation/trace/ftrace.rst
index b37dc19e4d40950fb46d9016cb99f4b905271580..60bceb018d6a9372cd57aaee4e16e54dc6595e10 100644 (file)
--- a/Documentation/trace/ftrace.rst
+++ b/Documentation/trace/ftrace.rst
@@ -564,7 +564,7 @@ of ftrace. Here is a list of some of the key files:
 
        start::
 
-               trace_fd = open("trace_marker", WR_ONLY);
+               trace_fd = open("trace_marker", O_WRONLY);
 
        Note: Writing into the trace_marker file can also initiate triggers
              that are written into /sys/kernel/tracing/events/ftrace/print/trigger