4c174688ee
Pull tracing updates from Steven Rostedt:
"New features for this release:
- Pretty much a full rewrite of the processing of function plugins.
i.e. echo do_IRQ:stacktrace > set_ftrace_filter
- The rewrite was needed to add plugins to be unique to tracing
instances. i.e. mkdir instance/foo; cd instances/foo; echo
do_IRQ:stacktrace > set_ftrace_filter The old way was written very
hacky. This removes a lot of those hacks.
- New "function-fork" tracing option. When set, pids in the
set_ftrace_pid will have their children added when the processes
with their pids listed in the set_ftrace_pid file forks.
- Exposure of "maxactive" for kretprobe in kprobe_events
- Allow for builtin init functions to be traced by the function
tracer (via the kernel command line). Module init function tracing
will come in the next release.
- Added more selftests, and have selftests also test in an instance"
* tag 'trace-v4.12' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (60 commits)
ring-buffer: Return reader page back into existing ring buffer
selftests: ftrace: Allow some event trigger tests to run in an instance
selftests: ftrace: Have some basic tests run in a tracing instance too
selftests: ftrace: Have event tests also run in an tracing instance
selftests: ftrace: Make func_event_triggers and func_traceonoff_triggers tests do instances
selftests: ftrace: Allow some tests to be run in a tracing instance
tracing/ftrace: Allow for instances to trigger their own stacktrace probes
tracing/ftrace: Allow for the traceonoff probe be unique to instances
tracing/ftrace: Enable snapshot function trigger to work with instances
tracing/ftrace: Allow instances to have their own function probes
tracing/ftrace: Add a better way to pass data via the probe functions
ftrace: Dynamically create the probe ftrace_ops for the trace_array
tracing: Pass the trace_array into ftrace_probe_ops functions
tracing: Have the trace_array hold the list of registered func probes
ftrace: If the hash for a probe fails to update then free what was initialized
ftrace: Have the function probes call their own function
ftrace: Have each function probe use its own ftrace_ops
ftrace: Have unregister_ftrace_function_probe_func() return a value
ftrace: Add helper function ftrace_hash_move_and_update_ops()
ftrace: Remove data field from ftrace_func_probe structure
...
Linux Ftrace Testcases
This is a collection of testcases for ftrace tracing feature in the Linux
kernel. Since ftrace exports interfaces via the debugfs, we just need
shell scripts for testing. Feel free to add new test cases.
Running the ftrace testcases
============================
At first, you need to be the root user to run this script.
To run all testcases:
$ sudo ./ftracetest
To run specific testcases:
# ./ftracetest test.d/basic3.tc
Or you can also run testcases under given directory:
# ./ftracetest test.d/kprobe/
Contributing new testcases
==========================
Copy test.d/template to your testcase (whose filename must have *.tc
extension) and rewrite the test description line.
* The working directory of the script is <debugfs>/tracing/.
* Take care with side effects as the tests are run with root privilege.
* The tests should not run for a long period of time (more than 1 min.)
These are to be unit tests.
* You can add a directory for your testcases under test.d/ if needed.
* The test cases should run on dash (busybox shell) for testing on
minimal cross-build environments.
* Note that the tests are run with "set -e" (errexit) option. If any
command fails, the test will be terminated immediately.
* The tests can return some result codes instead of pass or fail by
using exit_unresolved, exit_untested, exit_unsupported and exit_xfail.
Result code
===========
Ftracetest supports following result codes.
* PASS: The test succeeded as expected. The test which exits with 0 is
counted as passed test.
* FAIL: The test failed, but was expected to succeed. The test which exits
with !0 is counted as failed test.
* UNRESOLVED: The test produced unclear or intermidiate results.
for example, the test was interrupted
or the test depends on a previous test, which failed.
or the test was set up incorrectly
The test which is in above situation, must call exit_unresolved.
* UNTESTED: The test was not run, currently just a placeholder.
In this case, the test must call exit_untested.
* UNSUPPORTED: The test failed because of lack of feature.
In this case, the test must call exit_unsupported.
* XFAIL: The test failed, and was expected to fail.
To return XFAIL, call exit_xfail from the test.
There are some sample test scripts for result code under samples/.
You can also run samples as below:
# ./ftracetest samples/
TODO
====
* Fancy colored output :)