linux/tools/testing/selftests/ftrace
Linus Torvalds 99214f6778 Tracing fixes for 6.6:
- Add missing LOCKDOWN checks for eventfs callers
   When LOCKDOWN is active for tracing, it causes inconsistent state
   when some functions succeed and others fail.
 
 - Use dput() to free the top level eventfs descriptor
   There was a race between accesses and freeing it.
 
 - Fix a long standing bug that eventfs exposed due to changing timings
   by dynamically creating files. That is, If a event file is opened
   for an instance, there's nothing preventing the instance from being
   removed which will make accessing the files cause use-after-free bugs.
 
 - Fix a ring buffer race that happens when iterating over the ring
   buffer while writers are active. Check to make sure not to read
   the event meta data if it's beyond the end of the ring buffer sub buffer.
 
 - Fix the print trigger that disappeared because the test to create it
   was looking for the event dir field being filled, but now it has the
   "ef" field filled for the eventfs structure.
 
 - Remove the unused "dir" field from the event structure.
 
 - Fix the order of the trace_dynamic_info as it had it backwards for the
   offset and len fields for which one was for which endianess.
 
 - Fix NULL pointer dereference with eventfs_remove_rec()
   If an allocation fails in one of the eventfs_add_*() functions,
   the caller of it in event_subsystem_dir() or event_create_dir()
   assigns the result to the structure. But it's assigning the ERR_PTR
   and not NULL. This was passed to eventfs_remove_rec() which expects
   either a good pointer or a NULL, not ERR_PTR. The fix is to not
   assign the ERR_PTR to the structure, but to keep it NULL on error.
 
 - Fix list_for_each_rcu() to use list_for_each_srcu() in
   dcache_dir_open_wrapper(). One iteration of the code used RCU
   but because it had to call sleepable code, it had to be changed
   to use SRCU, but one of the iterations was missed.
 
 - Fix synthetic event print function to use "as_u64" instead of
   passing in a pointer to the union. To fix big/little endian issues,
   the u64 that represented several types was turned into a union to
   define the types properly.
 -----BEGIN PGP SIGNATURE-----
 
 iIoEABYIADIWIQRRSw7ePDh/lE+zeZMp5XQQmuv6qgUCZQCvoBQccm9zdGVkdEBn
 b29kbWlzLm9yZwAKCRAp5XQQmuv6qtgrAP9MiYiCMU+90oJ+61DFchbs3y7BNidP
 s3lLRDUMJ935NQD/SSAm54PqWb+YXMpD7m9+3781l6xqwfabBMXNaEl+FwA=
 =tlZu
 -----END PGP SIGNATURE-----

Merge tag 'trace-v6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull tracing fixes from Steven Rostedt:

 - Add missing LOCKDOWN checks for eventfs callers

   When LOCKDOWN is active for tracing, it causes inconsistent state
   when some functions succeed and others fail.

 - Use dput() to free the top level eventfs descriptor

   There was a race between accesses and freeing it.

 - Fix a long standing bug that eventfs exposed due to changing timings
   by dynamically creating files. That is, If a event file is opened for
   an instance, there's nothing preventing the instance from being
   removed which will make accessing the files cause use-after-free
   bugs.

 - Fix a ring buffer race that happens when iterating over the ring
   buffer while writers are active. Check to make sure not to read the
   event meta data if it's beyond the end of the ring buffer sub buffer.

 - Fix the print trigger that disappeared because the test to create it
   was looking for the event dir field being filled, but now it has the
   "ef" field filled for the eventfs structure.

 - Remove the unused "dir" field from the event structure.

 - Fix the order of the trace_dynamic_info as it had it backwards for
   the offset and len fields for which one was for which endianess.

 - Fix NULL pointer dereference with eventfs_remove_rec()

   If an allocation fails in one of the eventfs_add_*() functions, the
   caller of it in event_subsystem_dir() or event_create_dir() assigns
   the result to the structure. But it's assigning the ERR_PTR and not
   NULL. This was passed to eventfs_remove_rec() which expects either a
   good pointer or a NULL, not ERR_PTR. The fix is to not assign the
   ERR_PTR to the structure, but to keep it NULL on error.

 - Fix list_for_each_rcu() to use list_for_each_srcu() in
   dcache_dir_open_wrapper(). One iteration of the code used RCU but
   because it had to call sleepable code, it had to be changed to use
   SRCU, but one of the iterations was missed.

 - Fix synthetic event print function to use "as_u64" instead of passing
   in a pointer to the union. To fix big/little endian issues, the u64
   that represented several types was turned into a union to define the
   types properly.

* tag 'trace-v6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  eventfs: Fix the NULL pointer dereference bug in eventfs_remove_rec()
  tracefs/eventfs: Use list_for_each_srcu() in dcache_dir_open_wrapper()
  tracing/synthetic: Print out u64 values properly
  tracing/synthetic: Fix order of struct trace_dynamic_info
  selftests/ftrace: Fix dependencies for some of the synthetic event tests
  tracing: Remove unused trace_event_file dir field
  tracing: Use the new eventfs descriptor for print trigger
  ring-buffer: Do not attempt to read past "commit"
  tracefs/eventfs: Free top level files on removal
  ring-buffer: Avoid softlockup in ring_buffer_resize()
  tracing: Have event inject files inc the trace array ref count
  tracing: Have option files inc the trace array ref count
  tracing: Have current_trace inc the trace array ref count
  tracing: Have tracing_max_latency inc the trace array ref count
  tracing: Increase trace array ref count on enable and filter files
  tracefs/eventfs: Use dput to free the toplevel events directory
  tracefs/eventfs: Add missing lockdown checks
  tracefs: Add missing lockdown check to tracefs_create_dir()
2023-09-13 11:30:11 -07:00
..
samples ftracetest: Add POSIX.3 standard and XFAIL result codes 2014-10-03 16:44:02 -04:00
test.d Tracing fixes for 6.6: 2023-09-13 11:30:11 -07:00
.gitignore .gitignore: add SPDX License Identifier 2020-03-25 11:50:48 +01:00
Makefile selftests/ftrace: Improve integration with kselftest runner 2023-05-08 11:10:13 -06:00
README ftracetest: Add POSIX.3 standard and XFAIL result codes 2014-10-03 16:44:02 -04:00
config selftests/ftrace: Add CONFIG_SAMPLE_FTRACE_DIRECT=m kconfig 2020-04-14 10:00:29 -06:00
ftracetest selftests/ftace: Fix KTAP output ordering 2023-06-12 16:40:22 -06:00
ftracetest-ktap selftests/ftrace: Improve integration with kselftest runner 2023-05-08 11:10:13 -06:00
settings tracing/selftests: Turn off timeout setting 2019-11-14 13:15:11 -05:00

README

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 :)