linux/tools/testing/selftests/ftrace
Linus Torvalds 01732755ee Probes updates for v6.9:
- x96/kprobes: Use boolean for some function return instead of 0 and 1.
  - x86/kprobes: Prohibit probing on INT/UD. This prevents user to put kprobe on
     INTn/INT1/INT3/INTO and UD0/UD1/UD2 because these are used for a special
     purpose in the kernel.
  - x86/kprobes: Boost Grp instructions. Because a few percent of kernel
     instructions are Grp 2/3/4/5 and those are safe to be executed without
     ip register fixup, allow those to be boosted (direct execution on the
     trampoline buffer with a JMP).
 
  - tracing/probes: Add function argument access from return events (kretprobe
     and fprobe). This allows user to compare how a data structure field is
     changed after executing a function. With BTF, return event also accepts
     function argument access by name. This also includes below patches;
   . Fix a wrong comment (using "Kretprobe" in fprobe)
   . Cleanup a big probe argument parser function into three parts, type
      parser, post-processing function, and main parser.
   . Cleanup to set nr_args field when initializing trace_probe instead of
      counting up it while parsing.
   . Cleanup a redundant #else block from tracefs/README source code.
   . Update selftests to check entry argument access from return probes.
   . Documentation update about entry argument access from return probes.
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Merge tag 'probes-v6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull probes updates from Masami Hiramatsu:
 "x86 kprobes:

   - Use boolean for some function return instead of 0 and 1

   - Prohibit probing on INT/UD. This prevents user to put kprobe on
     INTn/INT1/INT3/INTO and UD0/UD1/UD2 because these are used for a
     special purpose in the kernel

   - Boost Grp instructions. Because a few percent of kernel
     instructions are Grp 2/3/4/5 and those are safe to be executed
     without ip register fixup, allow those to be boosted (direct
     execution on the trampoline buffer with a JMP)

  tracing:

   - Add function argument access from return events (kretprobe and
     fprobe). This allows user to compare how a data structure field is
     changed after executing a function. With BTF, return event also
     accepts function argument access by name.

   - Fix a wrong comment (using "Kretprobe" in fprobe)

   - Cleanup a big probe argument parser function into three parts, type
     parser, post-processing function, and main parser

   - Cleanup to set nr_args field when initializing trace_probe instead
     of counting up it while parsing

   - Cleanup a redundant #else block from tracefs/README source code

   - Update selftests to check entry argument access from return probes

   - Documentation update about entry argument access from return
     probes"

* tag 'probes-v6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  Documentation: tracing: Add entry argument access at function exit
  selftests/ftrace: Add test cases for entry args at function exit
  tracing/probes: Support $argN in return probe (kprobe and fprobe)
  tracing: Remove redundant #else block for BTF args from README
  tracing/probes: cleanup: Set trace_probe::nr_args at trace_probe_init
  tracing/probes: Cleanup probe argument parser
  tracing/fprobe-event: cleanup: Fix a wrong comment in fprobe event
  x86/kprobes: Boost more instructions from grp2/3/4/5
  x86/kprobes: Prohibit kprobing on INT and UD
  x86/kprobes: Refactor can_{probe,boost} return type to bool
2024-03-14 16:16:33 -07:00
..
samples
test.d Probes updates for v6.9: 2024-03-14 16:16:33 -07:00
.gitignore
config
ftracetest selftest/ftrace: fix typo in ftracetest script 2024-02-20 14:47:37 -07:00
ftracetest-ktap selftests/ftrace: Improve integration with kselftest runner 2023-05-08 11:10:13 -06:00
Makefile selftests/ftrace: Improve integration with kselftest runner 2023-05-08 11:10:13 -06:00
README
settings

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 :)