When user_events is not installed the self tests currently fail. Now
that these self tests run by default we need to ensure they don't fail
when user_events was not enabled for the kernel being tested.
Add common methods to detect if tracefs and user_events is enabled. If
either is not enabled skip the test. If tracefs is enabled, but is not
mounted, mount tracefs and fail if there were any errors. Fail if not
run as root.
Fixes: 68b4d2d583 ("selftests/user_events: Reenable build")
Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Link: https://lore.kernel.org/all/CA+G9fYuugZ0OMeS6HvpSS4nuf_A3s455ecipGBvER0LJHojKZg@mail.gmail.com/
Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
The canonical location for the tracefs filesystem is at /sys/kernel/tracing.
But, from Documentation/trace/ftrace.rst:
Before 4.1, all ftrace tracing control files were within the debugfs
file system, which is typically located at /sys/kernel/debug/tracing.
For backward compatibility, when mounting the debugfs file system,
the tracefs file system will be automatically mounted at:
/sys/kernel/debug/tracing
A few spots in tools/testing/selftests still refer to this older debugfs
path, so let's update them to avoid confusion.
Link: https://lkml.kernel.org/r/20230313211746.1541525-1-zwisler@kernel.org
Cc: "Tobin C. Harding" <me@tobin.cc>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Tycho Andersen <tycho@tycho.pizza>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Reviewed-by: Mukesh Ojha <quic_mojha@quicinc.com>
Signed-off-by: Ross Zwisler <zwisler@google.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
