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2025-07-28rv: Retry when da monitor detects race conditionsGabriele Monaco
DA monitor can be accessed from multiple cores simultaneously, this is likely, for instance when dealing with per-task monitors reacting on events that do not always occur on the CPU where the task is running. This can cause race conditions where two events change the next state and we see inconsistent values. E.g.: [62] event_srs: 27: sleepable x sched_wakeup -> running (final) [63] event_srs: 27: sleepable x sched_set_state_sleepable -> sleepable [63] error_srs: 27: event sched_switch_suspend not expected in the state running In this case the monitor fails because the event on CPU 62 wins against the one on CPU 63, although the correct state should have been sleepable, since the task get suspended. Detect if the current state was modified by using try_cmpxchg while storing the next value. If it was, try again reading the current state. After a maximum number of failed retries, react by calling a special tracepoint, print on the console and reset the monitor. Remove the functions da_monitor_curr_state() and da_monitor_set_state() as they only hide the underlying implementation in this case. Monitors where this type of condition can occur must be able to account for racing events in any possible order, as we cannot know the winner. Cc: Ingo Molnar <mingo@redhat.com> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Tomas Glozar <tglozar@redhat.com> Cc: Juri Lelli <jlelli@redhat.com> Cc: Clark Williams <williams@redhat.com> Cc: John Kacur <jkacur@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: https://lore.kernel.org/20250728135022.255578-6-gmonaco@redhat.com Signed-off-by: Gabriele Monaco <gmonaco@redhat.com> Reviewed-by: Nam Cao <namcao@linutronix.de> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-07-28rv: Adjust monitor dependenciesGabriele Monaco
RV monitors relying on the preemptirqs tracepoints are set as dependent on PREEMPT_TRACER and IRQSOFF_TRACER. In fact, those configurations do enable the tracepoints but are not the minimal configurations enabling them, which are TRACE_PREEMPT_TOGGLE and TRACE_IRQFLAGS (not selectable manually). Set TRACE_PREEMPT_TOGGLE and TRACE_IRQFLAGS as dependencies for monitors. Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Tomas Glozar <tglozar@redhat.com> Cc: Juri Lelli <jlelli@redhat.com> Cc: Clark Williams <williams@redhat.com> Cc: John Kacur <jkacur@redhat.com> Link: https://lore.kernel.org/20250728135022.255578-5-gmonaco@redhat.com Fixes: fbe6c09b7eb4 ("rv: Add scpd, snep and sncid per-cpu monitors") Acked-by: Nam Cao <namcao@linutronix.de> Signed-off-by: Gabriele Monaco <gmonaco@redhat.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-07-28rv: Use strings in da monitors tracepointsGabriele Monaco
Using DA monitors tracepoints with KASAN enabled triggers the following warning: BUG: KASAN: global-out-of-bounds in do_trace_event_raw_event_event_da_monitor+0xd6/0x1a0 Read of size 32 at addr ffffffffaada8980 by task ... Call Trace: <TASK> [...] do_trace_event_raw_event_event_da_monitor+0xd6/0x1a0 ? __pfx_do_trace_event_raw_event_event_da_monitor+0x10/0x10 ? trace_event_sncid+0x83/0x200 trace_event_sncid+0x163/0x200 [...] The buggy address belongs to the variable: automaton_snep+0x4e0/0x5e0 This is caused by the tracepoints reading 32 bytes __array instead of __string from the automata definition. Such strings are literals and reading 32 bytes ends up in out of bound memory accesses (e.g. the next automaton's data in this case). The error is harmless as, while printing the string, we stop at the null terminator, but it should still be fixed. Use the __string facilities while defining the tracepoints to avoid reading out of bound memory. Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Tomas Glozar <tglozar@redhat.com> Cc: Juri Lelli <jlelli@redhat.com> Cc: Clark Williams <williams@redhat.com> Cc: John Kacur <jkacur@redhat.com> Link: https://lore.kernel.org/20250728135022.255578-4-gmonaco@redhat.com Fixes: 792575348ff7 ("rv/include: Add deterministic automata monitor definition via C macros") Reviewed-by: Nam Cao <namcao@linutronix.de> Signed-off-by: Gabriele Monaco <gmonaco@redhat.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-07-28rv: Remove trailing whitespace from tracepoint stringGabriele Monaco
RV event tracepoints print a line with the format: "event_xyz: S0 x event -> S1 " "event_xyz: S1 x event -> S0 (final)" While printing an event leading to a non-final state, the line has a trailing white space (visible above before the closing "). Adapt the format string not to print the trailing whitespace if we are not printing "(final)". Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Tomas Glozar <tglozar@redhat.com> Cc: Juri Lelli <jlelli@redhat.com> Cc: Clark Williams <williams@redhat.com> Cc: John Kacur <jkacur@redhat.com> Link: https://lore.kernel.org/20250728135022.255578-3-gmonaco@redhat.com Reviewed-by: Nam Cao <namcao@linutronix.de> Signed-off-by: Gabriele Monaco <gmonaco@redhat.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-07-28rv: Add da_handle_start_run_event_ to per-task monitorsGabriele Monaco
The RV da_monitor API allows to start monitors in two ways: da_handle_start_event_NAME and da_handle_start_run_event_NAME. The former is used when the event is followed by the initial state of the module, so we ignore the event but we know the monitor is in the initial state and can start monitoring, the latter can be used if the event can only occur in the initial state, so we do handle the event as if the monitor was in the initial state. This latter API is defined for implicit monitors but not per-task ones. Define da_handle_start_run_event_NAME macro also for per-task monitors. Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Tomas Glozar <tglozar@redhat.com> Cc: Juri Lelli <jlelli@redhat.com> Cc: Clark Williams <williams@redhat.com> Cc: John Kacur <jkacur@redhat.com> Link: https://lore.kernel.org/20250728135022.255578-2-gmonaco@redhat.com Reviewed-by: Nam Cao <namcao@linutronix.de> Signed-off-by: Gabriele Monaco <gmonaco@redhat.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-07-28rv: Fix wrong type cast in reactors_show() and monitor_reactor_show()Nam Cao
Argument 'p' of reactors_show() and monitor_reactor_show() is not a pointer to struct rv_reactor, it is actually a pointer to the list_head inside struct rv_reactor. Therefore it's wrong to cast 'p' to struct rv_reactor *. This wrong type cast has been there since the beginning. But it still worked because the list_head was the first field in struct rv_reactor_def. This is no longer true since commit 3d3c376118b5 ("rv: Merge struct rv_reactor_def into struct rv_reactor") moved the list_head, and this wrong type cast became a functional problem. Properly use container_of() instead. Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Gabriele Monaco <gmonaco@redhat.com> Link: https://lore.kernel.org/b4febbd6844311209e4c8768b65d508b81bd8c9b.1753625621.git.namcao@linutronix.de Fixes: 3d3c376118b5 ("rv: Merge struct rv_reactor_def into struct rv_reactor") Signed-off-by: Nam Cao <namcao@linutronix.de> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-07-28rv: Fix wrong type cast in monitors_show()Nam Cao
Argument 'p' of monitors_show() is not a pointer to struct rv_monitor, it is actually a pointer to the list_head inside struct rv_monitor. Therefore it is wrong to cast 'p' to struct rv_monitor *. This wrong type cast has been there since the beginning. But it still worked because the list_head was the first field in struct rv_monitor_def. This is no longer true since commit 24cbfe18d55a ("rv: Merge struct rv_monitor_def into struct rv_monitor") moved the list_head, and this wrong type cast became a functional problem. Properly use container_of() instead. Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://lore.kernel.org/35e49e97696007919ceacf73796487a2e15a3d02.1753625621.git.namcao@linutronix.de Fixes: 24cbfe18d55a ("rv: Merge struct rv_monitor_def into struct rv_monitor") Signed-off-by: Nam Cao <namcao@linutronix.de> Reviewed-by: Gabriele Monaco <gmonaco@redhat.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-07-25rv: Remove struct rv_monitor::reactingNam Cao
The field 'reacting' in struct rv_monitor is set but never used. Delete it. Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://lore.kernel.org/a6c16f845d2f1a09c4d0934ab83f3cb14478a71d.1753378331.git.namcao@linutronix.de Reviewed-by: Gabriele Monaco <gmonaco@redhat.com> Signed-off-by: Nam Cao <namcao@linutronix.de> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-07-25rv: Remove rv_reactor's reference counterNam Cao
rv_reactor has a reference counter to ensure it is not removed while monitors are still using it. However, this is futile, as __exit functions are not expected to fail and will proceed normally despite rv_unregister_reactor() returning an error. At the moment, reactors do not support being built as modules, therefore they are never removed and the reference counters are not necessary. If we support building RV reactors as modules in the future, kernel module's centralized facilities such as try_module_get(), module_put() or MODULE_SOFTDEP should be used instead of this custom implementation. Remove this reference counter. Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://lore.kernel.org/bb946398436a5e17fb0f5b842ef3313c02291852.1753378331.git.namcao@linutronix.de Reviewed-by: Gabriele Monaco <gmonaco@redhat.com> Signed-off-by: Nam Cao <namcao@linutronix.de> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-07-25rv: Merge struct rv_reactor_def into struct rv_reactorNam Cao
Each struct rv_reactor has a unique struct rv_reactor_def associated with it. struct rv_reactor is statically allocated, while struct rv_reactor_def is dynamically allocated. This makes the code more complicated than it should be: - Lookup is required to get the associated rv_reactor_def from rv_reactor - Dynamic memory allocation is required for rv_reactor_def. This is harder to get right compared to static memory. For instance, there is an existing mistake: rv_unregister_reactor() does not free the memory allocated by rv_register_reactor(). This is fortunately not a real memory leak problem as rv_unregister_reactor() is never called. Simplify and merge rv_reactor_def into rv_reactor. Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://lore.kernel.org/71cb91c86cd40df5b8c492b788787f2a73c3eaa3.1753378331.git.namcao@linutronix.de Reviewed-by: Gabriele Monaco <gmonaco@redhat.com> Signed-off-by: Nam Cao <namcao@linutronix.de> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-07-25rv: Merge struct rv_monitor_def into struct rv_monitorNam Cao
Each struct rv_monitor has a unique struct rv_monitor_def associated with it. struct rv_monitor is statically allocated, while struct rv_monitor_def is dynamically allocated. This makes the code more complicated than it should be: - Lookup is required to get the associated rv_monitor_def from rv_monitor - Dynamic memory allocation is required for rv_monitor_def. This is harder to get right compared to static memory. For instance, there is an existing mistake: rv_unregister_monitor() does not free the memory allocated by rv_register_monitor(). This is fortunately not a real memory leak problem, as rv_unregister_monitor() is never called. Simplify and merge rv_monitor_def into rv_monitor. Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://lore.kernel.org/194449c00f87945c207aab4c96920c75796a4f53.1753378331.git.namcao@linutronix.de Reviewed-by: Gabriele Monaco <gmonaco@redhat.com> Signed-off-by: Nam Cao <namcao@linutronix.de> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-07-25rv: Remove unused field in struct rv_monitor_defNam Cao
rv_monitor_def::task_monitor is not used. Delete it. Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://lore.kernel.org/502d94f2696435690a2b1fdbe80a9e56c96fcabf.1753378331.git.namcao@linutronix.de Reviewed-by: Gabriele Monaco <gmonaco@redhat.com> Signed-off-by: Nam Cao <namcao@linutronix.de> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-07-24rv: Return init error when registering monitorsGabriele Monaco
Monitors generated with dot2k have their registration function (the one called during monitor initialisation) return always 0, even if the registration failed on RV side. This can hide potential errors. Return the value returned by the RV register function. Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Tomas Glozar <tglozar@redhat.com> Cc: Juri Lelli <jlelli@redhat.com> Cc: Clark Williams <williams@redhat.com> Cc: John Kacur <jkacur@redhat.com> Link: https://lore.kernel.org/20250723161240.194860-6-gmonaco@redhat.com Reviewed-by: Nam Cao <namcao@linutronix.de> Signed-off-by: Gabriele Monaco <gmonaco@redhat.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-07-24verification/rvgen: Organise Kconfig entries for nested monitorsGabriele Monaco
The current behaviour of rvgen when running with the -a option is to append the necessary lines at the end of the configuration for Kconfig, Makefile and tracepoints. This is not always the desired behaviour in case of nested monitors: while tracepoints are not affected by nesting and the Makefile's only requirement is that the parent monitor is built before its children, in the Kconfig it is better to have children defined right after their parent, otherwise the result has wrong indentation: [*] foo_parent monitor [*] foo_child1 monitor [*] foo_child2 monitor [*] bar_parent monitor [*] bar_child1 monitor [*] bar_child2 monitor [*] foo_child3 monitor [*] foo_child4 monitor Adapt rvgen to look for a different marker for nested monitors in the Kconfig file and append the line right after the last sibling, instead of the last monitor. Also add the marker when creating a new parent monitor. Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Tomas Glozar <tglozar@redhat.com> Cc: Juri Lelli <jlelli@redhat.com> Cc: Clark Williams <williams@redhat.com> Cc: John Kacur <jkacur@redhat.com> Link: https://lore.kernel.org/20250723161240.194860-5-gmonaco@redhat.com Reviewed-by: Nam Cao <namcao@linutronix.de> Signed-off-by: Gabriele Monaco <gmonaco@redhat.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-07-24tools/dot2c: Fix generated files going over 100 column limitGabriele Monaco
The dot2c.py script generates all states in a single line. This breaks the 100 column limit when the state machines are non-trivial. Change dot2c.py to generate the states in separate lines in case the generated line is going to be too long. Also adapt existing monitors with line length over the limit. Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Tomas Glozar <tglozar@redhat.com> Cc: Juri Lelli <jlelli@redhat.com> Cc: Clark Williams <williams@redhat.com> Cc: John Kacur <jkacur@redhat.com> Link: https://lore.kernel.org/20250723161240.194860-4-gmonaco@redhat.com Suggested-by: Nam Cao <namcao@linutronix.de> Signed-off-by: Gabriele Monaco <gmonaco@redhat.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-07-24tools/rv: Stop gracefully also on SIGTERMGabriele Monaco
Currently the userspace RV tool starts a monitor and waits for the user to press Ctrl-C (SIGINT) to terminate and stop the monitor. This doesn't account for a scenario where a user starts RV in background and simply kills it (SIGTERM unless the user specifies differently). E.g.: # rv mon wip & # kill % Would terminate RV without stopping the monitor and next RV executions won't start correctly. Register the signal handler used for SIGINT also to SIGTERM. Cc: Nam Cao <namcao@linutronix.de> Cc: Tomas Glozar <tglozar@redhat.com> Cc: Juri Lelli <jlelli@redhat.com> Cc: Clark Williams <williams@redhat.com> Cc: John Kacur <jkacur@redhat.com> Link: https://lore.kernel.org/20250723161240.194860-3-gmonaco@redhat.com Signed-off-by: Gabriele Monaco <gmonaco@redhat.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-07-24tools/rv: Do not skip idle in traceGabriele Monaco
Currently, the userspace RV tool skips trace events triggered by the RV tool itself, this can be changed by passing the parameter -s, which sets the variable config_my_pid to 0 (instead of the tool's PID). This has the side effect of skipping events generated by idle (PID 0). Set config_my_pid to -1 (an invalid pid) to avoid skipping idle. Cc: Nam Cao <namcao@linutronix.de> Cc: Tomas Glozar <tglozar@redhat.com> Cc: Juri Lelli <jlelli@redhat.com> Cc: Clark Williams <williams@redhat.com> Cc: John Kacur <jkacur@redhat.com> Link: https://lore.kernel.org/20250723161240.194860-2-gmonaco@redhat.com Fixes: 6d60f89691fc ("tools/rv: Add in-kernel monitor interface") Signed-off-by: Gabriele Monaco <gmonaco@redhat.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-07-24verification/rvgen: Do not generate unused variablesNam Cao
ltl2k generates all variable definition in both ltl_start() and ltl_possible_next_states(). However, these two functions may not use all the variables, causing "unused variable" compiler warning. Change the script to only generate used variables. Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://lore.kernel.org/636b2b2d99a9bd46a9f77a078d44ebd7ffc7508c.1752850449.git.namcao@linutronix.de Signed-off-by: Nam Cao <namcao@linutronix.de> Reviewed-by: Gabriele Monaco <gmonaco@redhat.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-07-24verification/rvgen: Generate each variable definition only onceNam Cao
If a variable appears multiple times in the specification, ltl2k generates multiple variable definitions. This fails the build. Make sure each variable is only defined once. Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Gabriele Monaco <gmonaco@redhat.com> Link: https://lore.kernel.org/107dcf0d0aa8482d5fbe0314c3138f61cd284e91.1752850449.git.namcao@linutronix.de Signed-off-by: Nam Cao <namcao@linutronix.de> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-07-24verification/rvgen: Support the 'next' operatorNam Cao
The 'next' operator is a unary operator. It is defined as: "next time, the operand must be true". Support this operator. For RV monitors, "next time" means the next invocation of ltl_validate(). Cc: John Ogness <john.ogness@linutronix.de> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://lore.kernel.org/9c32cec04dd18d2e956fddd84b0e0a2503daa75a.1752239482.git.namcao@linutronix.de Signed-off-by: Nam Cao <namcao@linutronix.de> Tested-by: Gabriele Monaco <gmonaco@redhat.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-07-24Documentation/rv: Add documentation for linear temporal logic monitorsNam Cao
Add documents describing linear temporal logic runtime verification monitors and how to generate them using rvgen. Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Gabriele Monaco <gmonaco@redhat.com> Link: https://lore.kernel.org/be13719e66fd8da147d7c69d5365aa23c52b743f.1751634289.git.namcao@linutronix.de Signed-off-by: Nam Cao <namcao@linutronix.de> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-07-24verification/rvgen: Add support for linear temporal logicNam Cao
Add support for generating RV monitors from linear temporal logic, similar to the generation of deterministic automaton monitors. Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Gabriele Monaco <gmonaco@redhat.com> Link: https://lore.kernel.org/f3c63b363ff9c5af3302ba2b5d92a26a98700eaf.1751634289.git.namcao@linutronix.de Signed-off-by: Nam Cao <namcao@linutronix.de> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-07-24verification/rvgen: Restructure the classes to prepare for LTL inclusionNam Cao
Both container generation and DA monitor generation is implemented in the class dot2k. That requires some ugly "if is_container ... else ...". If linear temporal logic support is added at the current state, the "if else" chain is longer and uglier. Furthermore, container generation is irrevelant to .dot files. It is therefore illogical to be implemented in class "dot2k". Clean it up, restructure the dot2k class into the following class hierarchy: (RVGenerator) /\ / \ / \ / \ / \ (Container) (Monitor) /\ / \ / \ / \ (dot2k) [ltl2k] <- intended This allows a simple and clean integration of LTL. Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://lore.kernel.org/692137a581ba6bee7a64d37fb7173ae137c47bbd.1751634289.git.namcao@linutronix.de Reviewed-by: Gabriele Monaco <gmonaco@redhat.com> Signed-off-by: Nam Cao <namcao@linutronix.de> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-07-24verification/rvgen: Restructure the templates filesNam Cao
To simply the scripts and to allow easy integration of new monitor types, restructure the template files as followed: 1. Move the template files to be in the same directory as the rvgen package. Furthermore, the installation will now only install the templates to the package directory, not /usr/share/. This simplify templates reading, as the scripts do not need to find the templates at multiple places. 2. Move dot2k_templates/* to: - templates/dot2k/ - templates/container/ This allows sharing templates reading code between DA monitor generation and container generation (and any future generation type). For template files which can be shared between different generation types, support putting them in templates/ This restructure aligns with the recommendation from: https://python-packaging.readthedocs.io/en/latest/non-code-files.html Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://lore.kernel.org/462d90273f96804d3ba850474877d5f727031258.1751634289.git.namcao@linutronix.de Reviewed-by: Gabriele Monaco <gmonaco@redhat.com> Signed-off-by: Nam Cao <namcao@linutronix.de> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-07-24Documentation/rv: Prepare monitor synthesis document for LTL inclusionNam Cao
Monitor synthesis from deterministic automaton and linear temporal logic have a lot in common. Therefore a single document should describe both. Change da_monitor_synthesis.rst to monitor_synthesis.rst. LTL monitor synthesis will be added to this file by a follow-up commit. This makes the diff far easier to read. If renaming and adding LTL info is done in a single commit, git wouldn't recognize it as a rename, but a file removal and a file addition. While at it, correct the old dot2k commands to the new rvgen commands. Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://lore.kernel.org/d91c6e4600287f4732d68a014219e576a75ce6dc.1751634289.git.namcao@linutronix.de Reviewed-by: Gabriele Monaco <gmonaco@redhat.com> Signed-off-by: Nam Cao <namcao@linutronix.de> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-07-24verification/dot2k: Prepare the frontend for LTL inclusionNam Cao
The dot2k tool has some code that can be reused for linear temporal logic monitor. Prepare its frontend for LTL inclusion: 1. Rename to be generic: rvgen 2. Replace the parameter --dot with 2 parameters: --class: to specific the monitor class, can be 'da' or 'ltl' --spec: the monitor specification file, .dot file for DA, and .ltl file for LTL The old command: python3 dot2/dot2k monitor -d wip.dot -t per_cpu is equivalent to the new commands: python3 rvgen monitor -c da -s wip.dot -t per_cpu Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://lore.kernel.org/dea18f7a44374e4db8df5c7e785604bc3062ffc9.1751634289.git.namcao@linutronix.de Reviewed-by: Gabriele Monaco <gmonaco@redhat.com> Signed-off-by: Nam Cao <namcao@linutronix.de> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-07-24verification/dot2k: Replace is_container() hack with subparsersNam Cao
dot2k is used for both generating deterministic automaton (DA) monitor and generating container monitor. Generating DA monitor and generating container requires different parameters. This is implemented by peeking at sys.argv and check whether "--container" is specified, and use that information to make some parameters optional or required. This works, but is quite hacky and ugly. Replace this hack with Python's built-in subparsers. The old commands: python3 dot2/dot2k -d wip.dot -t per_cpu python3 dot2/dot2k -n sched --container are equivalent to the new commands: python3 dot2/dot2k monitor -d wip.dot -t per_cpu python3 dot2/dot2k container -n sched Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://lore.kernel.org/23c4e3c6e10c39e86d8e6a289208dde407efc4a8.1751634289.git.namcao@linutronix.de Reviewed-by: Gabriele Monaco <gmonaco@redhat.com> Signed-off-by: Nam Cao <namcao@linutronix.de> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-07-24verification/dot2k: Remove __buff_to_string()Nam Cao
str.join() can do what __buff_to_string() does. Therefore replace __buff_to_string() to make the scripts more pythonic. Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://lore.kernel.org/860d6002659f604c743e0f23d5cf3c99ea6a82d8.1751634289.git.namcao@linutronix.de Reviewed-by: Gabriele Monaco <gmonaco@redhat.com> Signed-off-by: Nam Cao <namcao@linutronix.de> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-07-24verification/dot2k: Make a separate dot2k_templates/Kconfig_containerNam Cao
A generated container's Kconfig has an incorrect line: select DA_MON_EVENTS_IMPLICIT This is due to container generation uses the same template Kconfig file as deterministic automaton monitor. Therefore, make a separate Kconfig template for container which has only the necessaries for container. Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://lore.kernel.org/d54fd7ee120785bec5695220e837dbbd6efb30e5.1751634289.git.namcao@linutronix.de Reviewed-by: Gabriele Monaco <gmonaco@redhat.com> Signed-off-by: Nam Cao <namcao@linutronix.de> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-07-22rv/ltl: Do not execute the Buchi automaton twice on start conditionNam Cao
On start condition of a Buchi automaton, the automaton is executed twice. This is fine for now, as all the current LTL operators do not care about this. But it would break the 'next' operator, which will be introduced in a follow-up patch. Prepare for the introduction of the 'next' operator, only execute the automaton once on start condition. Cc: John Ogness <john.ogness@linutronix.de> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Gabriele Monaco <gmonaco@redhat.com> Link: https://lore.kernel.org/9379f4e7b9c1c69a6dca3e20a22936c850a25ca7.1752239482.git.namcao@linutronix.de Signed-off-by: Nam Cao <namcao@linutronix.de> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-07-11panic: Fix up description of vpanic()Nam Cao
The description above vpanic() has the wrong function name. Fix it up. Cc: John Ogness <john.ogness@linutronix.de> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Gabriele Monaco <gmonaco@redhat.com> Cc: Josh Poimboeuf <jpoimboe@kernel.org> Cc: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/23a7e8add6546b155371b7e0fbb37bb1def13d6e.1752232374.git.namcao@linutronix.de Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Closes: https://lore.kernel.org/lkml/20250711183802.2d8c124d@canb.auug.org.au/ Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Nam Cao <namcao@linutronix.de> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-07-11objtool: Add vpanic() to the noreturn listNam Cao
vpanic() does not return. However, objtool doesn't know this and gets confused: kernel/trace/rv/reactor_panic.o: warning: objtool: rv_panic_reaction(): unexpected end of section .text Add vpanic() to the list of noreturn functions. Cc: John Ogness <john.ogness@linutronix.de> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Gabriele Monaco <gmonaco@redhat.com> Cc: Josh Poimboeuf <jpoimboe@kernel.org> Cc: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/073f826ebec18b2bb59cba88606cd865d8039fd2.1752232374.git.namcao@linutronix.de Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202507110826.2ekbVdWZ-lkp@intel.com/ Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Nam Cao <namcao@linutronix.de> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-07-09rv: Allow to configure the number of per-task monitorNam Cao
Now that there are 2 monitors for real-time applications, users may want to enable both of them simultaneously. Make the number of per-task monitor configurable. Default it to 2 for now. Cc: John Ogness <john.ogness@linutronix.de> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://lore.kernel.org/93e83313fc4ba7f6e66f4abe80ca5f5494d658d0.1752088709.git.namcao@linutronix.de Reviewed-by: Gabriele Monaco <gmonaco@redhat.com> Signed-off-by: Nam Cao <namcao@linutronix.de> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-07-09rv: Add documentation for rtapp monitorNam Cao
Add documentation describing the rtapp monitor. Cc: John Ogness <john.ogness@linutronix.de> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://lore.kernel.org/df0242d74c12511e82cc9d73c082def91a160c74.1752088709.git.namcao@linutronix.de Reviewed-by: Gabriele Monaco <gmonaco@redhat.com> Signed-off-by: Nam Cao <namcao@linutronix.de> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-07-09rv: Add rtapp_sleep monitorNam Cao
Add a monitor for checking that real-time tasks do not go to sleep in a manner that may cause undesirable latency. Also change RV depends on TRACING to RV select TRACING to avoid the following recursive dependency: error: recursive dependency detected! symbol TRACING is selected by PREEMPTIRQ_TRACEPOINTS symbol PREEMPTIRQ_TRACEPOINTS depends on TRACE_IRQFLAGS symbol TRACE_IRQFLAGS is selected by RV_MON_SLEEP symbol RV_MON_SLEEP depends on RV symbol RV depends on TRACING Cc: John Ogness <john.ogness@linutronix.de> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://lore.kernel.org/75bc5bcc741d153aa279c95faf778dff35c5c8ad.1752088709.git.namcao@linutronix.de Reviewed-by: Gabriele Monaco <gmonaco@redhat.com> Signed-off-by: Nam Cao <namcao@linutronix.de> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-07-09rv: Add rtapp_pagefault monitorNam Cao
Userspace real-time applications may have design flaws that they raise page faults in real-time threads, and thus have unexpected latencies. Add an linear temporal logic monitor to detect this scenario. Cc: John Ogness <john.ogness@linutronix.de> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://lore.kernel.org/78fea8a2de6d058241d3c6502c1a92910772b0ed.1752088709.git.namcao@linutronix.de Reviewed-by: Gabriele Monaco <gmonaco@redhat.com> Signed-off-by: Nam Cao <namcao@linutronix.de> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-07-09riscv: mm: Add page fault trace pointsNam Cao
Add page fault trace points, which are useful to implement RV monitor that watches page faults. Signed-off-by: Nam Cao <namcao@linutronix.de> Acked-by: Alexandre Ghiti <alexghiti@rivosinc.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-07-09rv: Add rtapp container monitorNam Cao
Add the container "rtapp" which is the monitor collection for detecting problems with real-time applications. The monitors will be added in the follow-up commits. Cc: John Ogness <john.ogness@linutronix.de> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://lore.kernel.org/fb18b87631d386271de00959d8d4826f23fcd1cd.1752088709.git.namcao@linutronix.de Reviewed-by: Gabriele Monaco <gmonaco@redhat.com> Signed-off-by: Nam Cao <namcao@linutronix.de> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-07-09rv: Add support for LTL monitorsNam Cao
While attempting to implement DA monitors for some complex specifications, deterministic automaton is found to be inappropriate as the specification language. The automaton is complicated, hard to understand, and error-prone. For these cases, linear temporal logic is more suitable as the specification language. Add support for linear temporal logic runtime verification monitor. Cc: John Ogness <john.ogness@linutronix.de> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Gabriele Monaco <gmonaco@redhat.com> Link: https://lore.kernel.org/d366c1fed60ed4e8f6451f3c15a99755f2740b5f.1752088709.git.namcao@linutronix.de Signed-off-by: Nam Cao <namcao@linutronix.de> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-07-09rv: rename CONFIG_DA_MON_EVENTS to CONFIG_RV_MON_EVENTSNam Cao
CONFIG_DA_MON_EVENTS is not specific to deterministic automaton. It could be used for other monitor types. Therefore rename it to CONFIG_RV_MON_EVENTS. This prepares for the introduction of linear temporal logic monitor. Cc: John Ogness <john.ogness@linutronix.de> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://lore.kernel.org/507210517123d887c1d208aa2fd45ec69765d3f0.1752088709.git.namcao@linutronix.de Reviewed-by: Gabriele Monaco <gmonaco@redhat.com> Signed-off-by: Nam Cao <namcao@linutronix.de> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-07-09rv: Let the reactors take care of buffersNam Cao
Each RV monitor has one static buffer to send to the reactors. If multiple errors are detected simultaneously, the one buffer could be overwritten. Instead, leave it to the reactors to handle buffering. Reviewed-by: Gabriele Monaco <gmonaco@redhat.com> Signed-off-by: Nam Cao <namcao@linutronix.de> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-07-09panic: Add vpanic()Nam Cao
vpanic() is useful for implementing runtime verification reactors. Add it. Signed-off-by: Nam Cao <namcao@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-07-09printk: Make vprintk_deferred() publicNam Cao
vprintk_deferred() is useful for implementing runtime verification reactors. Make it public. Signed-off-by: Nam Cao <namcao@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-07-09rv: Add #undef TRACE_INCLUDE_FILENam Cao
Without "#undef TRACE_INCLUDE_FILE", there could be a build error due to TRACE_INCLUDE_FILE being redefined. Therefore add it. Also fix a typo while at it. Cc: John Ogness <john.ogness@linutronix.de> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://lore.kernel.org/f805e074581e927bb176c742c981fa7675b6ebe5.1752088709.git.namcao@linutronix.de Reviewed-by: Gabriele Monaco <gmonaco@redhat.com> Signed-off-by: Nam Cao <namcao@linutronix.de> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-07-06Linux 6.16-rc5Linus Torvalds
2025-07-06Merge tag 'pull-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfsLinus Torvalds
Pull /proc/sys dcache lookup fix from Al Viro: "Fix for the breakage spotted by Neil in the interplay between /proc/sys ->d_compare() weirdness and parallel lookups" * tag 'pull-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: fix proc_sys_compare() handling of in-lookup dentries
2025-07-06Merge tag 'sched_urgent_for_v6.16_rc5' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler fixes from Borislav Petkov: - Fix the calculation of the deadline server task's runtime as this mishap was preventing realtime tasks from running - Avoid a race condition during migrate-swapping two tasks - Fix the string reported for the "none" dynamic preemption option * tag 'sched_urgent_for_v6.16_rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/deadline: Fix dl_server runtime calculation formula sched/core: Fix migrate_swap() vs. hotplug sched: Fix preemption string of preempt_dynamic_none
2025-07-06Merge tag 'objtool_urgent_for_v6.16_rc5' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull objtool fix from Borislav Petkov: - Fix the compilation of an x86 kernel on a big engian machine due to a missed endianness conversion * tag 'objtool_urgent_for_v6.16_rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: objtool: Add missing endian conversion to read_annotate()
2025-07-06Merge tag 'perf_urgent_for_v6.16_rc5' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fixes from Borislav Petkov: - Revert uprobes to using CAP_SYS_ADMIN again as currently they can destructively modify kernel code from an unprivileged process - Move a warning to where it belongs * tag 'perf_urgent_for_v6.16_rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf: Revert to requiring CAP_SYS_ADMIN for uprobes perf/core: Fix the WARN_ON_ONCE is out of lock protected region
2025-07-06Merge tag 'x86_urgent_for_v6.16_rc5' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fix from Borislav Petkov: - Make sure AMD SEV guests using secure TSC, include a TSC_FACTOR which prevents their TSCs from going skewed from the hypervisor's * tag 'x86_urgent_for_v6.16_rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/sev: Use TSC_FACTOR for Secure TSC frequency calculation