linux.git/Documentation/tools, branch master

Merge tag 'trace-rtla-v7.1' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

2026-04-16T00:48:24+00:00

Pull RTLA updates from Steven Rostedt:

- Simplify option parsing

Auto-generate getopt_long() optstring for short options from long
options array, avoiding the need to specify it manually and reducing
the surface for mistakes.

- Add unit tests

Implement unit tests (make unit-tests) using libcheck, next to
existing runtime tests (make check). Currently, three functions from
utils.c are tested.

- Add --stack-format option

In addition to stopping stack pointer decoding (with -s/--stack
option) on first unresolvable pointer, allow also skipping
unresolvable pointers and displaying everything, configurable with a
new option.

- Unify number of CPUs into one global variable

Use one global variable, nr_cpus, to store the number of CPUs instead
of retrieving it and passing it at multiple places.

- Fix behavior in various corner cases

Make RTLA behave correctly in several corner cases: memory allocation
failure, invalid value read from kernel side, thread creation
failure, malformed time value input, and read/write failure or
interruption by signal.

- Improve string handling

Simplify several places in the code that handle strings, including
parsing of action arguments. A few new helper functions and variables
are added for that purpose.

- Get rid of magic numbers

Few places handling paths use a magic number of 1024. Replace it with
MAX_PATH and ARRAY_SIZE() macro.

- Unify threshold handling

Code that handles response to latency threshold is duplicated between
tools, which has led to bugs in the past. Unify it into a new helper
as much as possible.

- Fix segfault on SIGINT during cleanup

The SIGINT handler touches dynamically allocated memory. Detach it
before freeing it during cleanup to prevent segmentation fault and
discarding of output buffers. Also, properly document SIGINT handling
while at it.

* tag 'trace-rtla-v7.1' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (28 commits)
Documentation/rtla: Document SIGINT behavior
rtla: Fix segfault on multiple SIGINTs
rtla/utils: Fix loop condition in PID validation
rtla/utils: Fix resource leak in set_comm_sched_attr()
rtla/trace: Fix I/O handling in save_trace_to_file()
rtla/trace: Fix write loop in trace_event_save_hist()
rtla/timerlat: Simplify RTLA_NO_BPF environment variable check
rtla: Use str_has_prefix() for option prefix check
rtla: Enforce exact match for time unit suffixes
rtla: Use str_has_prefix() for prefix checks
rtla: Add str_has_prefix() helper function
rtla: Handle pthread_create() failure properly
rtla/timerlat: Add bounds check for softirq vector
rtla: Simplify code by caching string lengths
rtla: Replace magic number with MAX_PATH
rtla: Introduce common_threshold_handler() helper
rtla/actions: Simplify argument parsing
rtla: Use strdup() to simplify code
rtla: Exit on memory allocation failures during initialization
tools/rtla: Remove unneeded nr_cpus from for_each_monitored_cpu
...

Merge tag 'trace-rv-v7.1' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

2026-04-16T00:15:18+00:00

Pull runtime verification updates from Steven Rostedt:

 - Refactor da_monitor header to share handlers across monitor types

   No functional changes, only less code duplication.

 - Add Hybrid Automata model class

   Add a new model class that extends deterministic automata by adding
   constraints on transitions and states. Those constraints can take
   into account wall-clock time and as such allow RV monitor to make
   assertions on real time. Add documentation and code generation
   scripts.

 - Add stall monitor as hybrid automaton example

   Add a monitor that triggers a violation when a task is stalling as an
   example of automaton working with real time variables.

 - Convert the opid monitor to a hybrid automaton

   The opid monitor can be heavily simplified if written as a hybrid
   automaton: instead of tracking preempt and interrupt enable/disable
   events, it can just run constraints on the preemption/interrupt
   states when events like wakeup and need_resched verify.

 - Add support for per-object monitors in DA/HA

   Allow writing deterministic and hybrid automata monitors for generic
   objects (e.g. any struct), by exploiting a hash table where objects
   are saved. This allows to track more than just tasks in RV. For
   instance it will be used to track deadline entities in deadline
   monitors.

 - Add deadline tracepoints and move some deadline utilities

   Prepare the ground for deadline monitors by defining events and
   exporting helpers.

 - Add nomiss deadline monitor

   Add first example of deadline monitor asserting all entities complete
   before their deadline.

 - Improve rvgen error handling

   Introduce AutomataError exception class and better handle expected
   exceptions while showing a backtrace for unexpected ones.

 - Improve python code quality in rvgen

   Refactor the rvgen generation scripts to align with python best
   practices: use f-strings instead of %, use len() instead of
   __len__(), remove semicolons, use context managers for file
   operations, fix whitespace violations, extract magic strings into
   constants, remove unused imports and methods.

 - Fix small bugs in rvgen

   The generator scripts presented some corner case bugs: logical error
   in validating what a correct dot file looks like, fix an isinstance()
   check, enforce a dot file has an initial state, fix type annotations
   and typos in comments.

 - rvgen refactoring

   Refactor automata.py to use iterator-based parsing and handle
   required arguments directly in argparse.

 - Allow epoll in rtapp-sleep monitor

   The epoll_wait call is now rt-friendly so it should be allowed in the
   sleep monitor as a valid sleep method.

* tag 'trace-rv-v7.1' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (32 commits)
  rv: Allow epoll in rtapp-sleep monitor
  rv/rvgen: fix _fill_states() return type annotation
  rv/rvgen: fix unbound loop variable warning
  rv/rvgen: enforce presence of initial state
  rv/rvgen: extract node marker string to class constant
  rv/rvgen: fix isinstance check in Variable.expand()
  rv/rvgen: make monitor arguments required in rvgen
  rv/rvgen: remove unused __get_main_name method
  rv/rvgen: remove unused sys import from dot2c
  rv/rvgen: refactor automata.py to use iterator-based parsing
  rv/rvgen: use class constant for init marker
  rv/rvgen: fix DOT file validation logic error
  rv/rvgen: fix PEP 8 whitespace violations
  rv/rvgen: fix typos in automata and generator docstring and comments
  rv/rvgen: use context managers for file operations
  rv/rvgen: remove unnecessary semicolons
  rv/rvgen: replace __len__() calls with len()
  rv/rvgen: replace % string formatting with f-strings
  rv/rvgen: remove bare except clauses in generator
  rv/rvgen: introduce AutomataError exception class
  ...

Documentation/rtla: Convert links to RST format

2026-04-09T14:23:12+00:00

Web links in the documentation are not properly displayed.

In the man pages web links look like:
  Osnoise tracer  documentation:  <   >

On web pages the URL caption is the URL itself.

Convert tracer documentation links to RST anonymous hyperlink format
for better rendering. Use newer docs.kernel.org instead of
www.kernel.org/doc/html/latest for brevity.

After the change, the links in the man pages look like:
  Osnoise tracer 

On web pages the captions are the titles of the links.

Signed-off-by: Costa Shulyupin 
Signed-off-by: Jonathan Corbet 
Message-ID: <20260405163847.3337981-1-costa.shul@redhat.com>

rv: Add sample hybrid monitor stall

2026-03-31T14:47:17+00:00

Add a sample monitor to showcase hybrid/timed automata.
The stall monitor identifies tasks stalled for longer than a threshold
and reacts when that happens.

Reviewed-by: Nam Cao 
Link: https://lore.kernel.org/r/20260330111010.153663-7-gmonaco@redhat.com
Signed-off-by: Gabriele Monaco

Documentation/rtla: Document SIGINT behavior

2026-03-27T09:58:30+00:00

The behavior of RTLA on receiving SIGINT is currently undocumented.

Describe it in RTLA's common appendix that appears in man pages for all
RTLA tools to avoid confusion.

Suggested-by: Attila Fazekas 
Reviewed-by: Steven Rostedt (Google) 
Link: https://lore.kernel.org/r/20260324123229.152424-1-tglozar@redhat.com
Signed-off-by: Tomas Glozar

docs: tools: include kdoc_yaml_file at documentation

2026-03-25T19:36:45+00:00

Add an autodoc entry for the new kdoc_yaml_file module.

Signed-off-by: Mauro Carvalho Chehab 
Signed-off-by: Jonathan Corbet 
Message-ID: <32b86abe7acee2dd4f73a35836ec94e8690f04cd.1774256269.git.mchehab+huawei@kernel.org>

docs: kdoc: add c_lex to generated documentation

2026-03-22T21:10:40+00:00

Do some fixes at groups() description for it to be parsed by
Sphinx and add it to the documentation.

Signed-off-by: Mauro Carvalho Chehab 
Signed-off-by: Jonathan Corbet 
Message-ID: <799178cf30dd4022fdb1d029ba998a458e037b52.1773823995.git.mchehab+huawei@kernel.org>

docs: python: add helpers to run unit tests

2026-03-22T21:02:29+00:00

While python internal libraries have support for unit tests, its
output is not nice. Add a helper module to improve its output.

I wrote this module last year while testing some scripts I used
internally. The initial skeleton was generated with the help of
LLM tools, but it was higly modified to ensure that it will work
as I would expect.

Signed-off-by: Mauro Carvalho Chehab 
Message-ID: <37999041f616ddef41e84cf2686c0264d1a51dc9.1773074166.git.mchehab+huawei@kernel.org>
Signed-off-by: Jonathan Corbet 
Message-ID:

Documentation/rtla: Document --stack-format option

2026-03-04T14:51:56+00:00

Add documentation for --stack-format option of rtla-timerlat into its
common options.

Reviewed-by: Wander Lairson Costa 
Link: https://lore.kernel.org/r/20260119115222.744150-2-tglozar@redhat.com
Signed-off-by: Tomas Glozar

docs: kdoc_parser: move transform lists to a separate file

2026-03-03T17:47:25+00:00

Over the time, most of the changes at kernel-doc are related
to maintaining a list of transforms to convert macros into pure
C code.

Place such transforms on a separate module, to cleanup the
parser module.

There is an advantage on that: QEMU also uses our own kernel-doc,
but the xforms list there is different. By placing it on a
separate module, we can minimize the differences and make it
easier to keep QEMU in sync with Kernel upstream.

No functional changes.

Signed-off-by: Mauro Carvalho Chehab 
Reviewed-by: Aleksandr Loktionov 
Signed-off-by: Jonathan Corbet 
Message-ID: