linux/kernel/trace/rv/rv_reactors.c, branch v6.19

rv: Convert to use __free

2025-12-02T06:28:32Z

Convert to use __free to tidy up the code. Signed-off-by: Nam Cao Reviewed-by: Gabriele Monaco Link: https://lore.kernel.org/r/62854e2fcb8f8dd2180a98a9700702dcf89a6980.1763370183.git.namcao@linutronix.de Signed-off-by: Gabriele Monaco

rv: Convert to use lock guard

2025-12-02T06:28:20Z

Convert to use lock guard to tidy up the code. Signed-off-by: Nam Cao Reviewed-by: Gabriele Monaco Link: https://lore.kernel.org/r/dbefeb868093c40d4b29fd6b57294a6aa011b719.1763370183.git.namcao@linutronix.de Signed-off-by: Gabriele Monaco

rv: Add explicit lockdep context for reactors

2025-11-11T12:18:56Z

Reactors can be called from any context through tracepoints. When developing reactors care needs to be taken to only call APIs which are safe. As the tracepoints used during testing may not actually be called from restrictive contexts lockdep may not be helpful. Add explicit overrides to help lockdep find invalid code patterns. The usage of LD_WAIT_FREE will trigger lockdep warnings in the panic reactor. These are indeed valid warnings but they are out of scope for RV and will instead be fixed by the printk subsystem. Signed-off-by: Thomas Weißschuh Acked-by: Nam Cao Link: https://lore.kernel.org/r/20251014-rv-lockdep-v1-3-0b9e51919ea8@linutronix.de Signed-off-by: Gabriele Monaco

rv: Make rv_reacting_on() static

2025-11-11T12:18:56Z

There are no external users left. Signed-off-by: Thomas Weißschuh Link: https://lore.kernel.org/r/20251014-rv-lockdep-v1-2-0b9e51919ea8@linutronix.de Signed-off-by: Gabriele Monaco

rv: Pass va_list to reactors

2025-11-11T12:18:55Z

The only thing the reactors can do with the passed in varargs is to convert it into a va_list. Do that in a central helper instead. It simplifies the reactors, removes some hairy macro-generated code and introduces a convenient hook point to modify reactor behavior. Signed-off-by: Thomas Weißschuh Link: https://lore.kernel.org/r/20251014-rv-lockdep-v1-1-0b9e51919ea8@linutronix.de Signed-off-by: Gabriele Monaco

rv: Fix wrong type cast in reactors_show() and monitor_reactor_show()

2025-07-28T14:39:34Z

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 Cc: Mathieu Desnoyers Cc: Gabriele Monaco 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 Signed-off-by: Steven Rostedt (Google)

rv: Remove struct rv_monitor::reacting

2025-07-25T13:04:14Z

The field 'reacting' in struct rv_monitor is set but never used. Delete it. Cc: Masami Hiramatsu Cc: Mathieu Desnoyers Link: https://lore.kernel.org/a6c16f845d2f1a09c4d0934ab83f3cb14478a71d.1753378331.git.namcao@linutronix.de Reviewed-by: Gabriele Monaco Signed-off-by: Nam Cao Signed-off-by: Steven Rostedt (Google)

rv: Remove rv_reactor's reference counter

2025-07-25T13:04:14Z

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 Cc: Mathieu Desnoyers Link: https://lore.kernel.org/bb946398436a5e17fb0f5b842ef3313c02291852.1753378331.git.namcao@linutronix.de Reviewed-by: Gabriele Monaco Signed-off-by: Nam Cao Signed-off-by: Steven Rostedt (Google)

rv: Merge struct rv_reactor_def into struct rv_reactor

2025-07-25T13:04:14Z

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 Cc: Mathieu Desnoyers Link: https://lore.kernel.org/71cb91c86cd40df5b8c492b788787f2a73c3eaa3.1753378331.git.namcao@linutronix.de Reviewed-by: Gabriele Monaco Signed-off-by: Nam Cao Signed-off-by: Steven Rostedt (Google)

rv: Merge struct rv_monitor_def into struct rv_monitor

2025-07-25T13:04:14Z

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 Cc: Mathieu Desnoyers Link: https://lore.kernel.org/194449c00f87945c207aab4c96920c75796a4f53.1753378331.git.namcao@linutronix.de Reviewed-by: Gabriele Monaco Signed-off-by: Nam Cao Signed-off-by: Steven Rostedt (Google)