selftests: ftrace: Use "grep -E" instead of "egrep"

The latest version of grep claims the egrep is now obsolete so the build
now contains warnings that look like:
egrep: warning: egrep is obsolescent; using grep -E
fix this up by moving the related file to use "grep -E" instead.

sed -i "s/egrep/grep -E/g" `grep egrep -rwl tools/testing/selftests/ftrace`

Here are the steps to install the latest grep:

wget http://ftp.gnu.org/gnu/grep/grep-3.8.tar.gz
tar xf grep-3.8.tar.gz
cd grep-3.8 && ./configure && make
sudo make install
export PATH=/usr/local/bin:$PATH

Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

selftests/ftrace: Support ":tracer" suffix for requires

Add ":tracer" suffix support for the requires list, so that
the testcase can list up the required tracer (e.g. function)
to the requires list.

For example, if the testcase requires function_graph tracer,
it can write requires list as below instead of checking
available_tracers.

# requires: function_graph:tracer

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

selftests/ftrace: mark irqsoff_tracer.tc test as unresolved if the test module does not exist

The UNRESOLVED state is much more apporiate than the UNSUPPORTED state
for the absence of the test module, as it matches "test was set up
incorrectly" situation in the README file.

A possible scenario is that the function was enabled (supported by the
kernel) but the module was not installed properly, in this case we
cannot call this as UNSUPPORTED.

This change also make it consistent with other module-related tests
in ftrace.

Signed-off-by: Po-Hsu Lin <po-hsu.lin@canonical.com>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kselftests: Add tests for the preemptoff and irqsoff tracers

Here we add unit tests for the preemptoff and irqsoff tracer by using a
kernel module introduced previously to trigger long preempt or irq
disabled sections in the kernel.

Link: http://lkml.kernel.org/r/20180711063540.91101-3-joel@joelfernandes.org

Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>