Add the rvgen kunit subcommand to patch an already generated monitor for
kunit support. It parses the handlers and create the necessary structs
and initialisations.
The only remaining manual steps are importing the test in the runner
and writing the test itself.
Reviewed-by: Nam Cao <namcao@linutronix.de>
Link: https://lore.kernel.org/r/20260723074534.43521-10-gmonaco@redhat.com
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
The rvgen code generator needs validation to ensure it produces correct
monitor implementations from input specifications.
Add selftests with golden reference outputs covering all monitor classes
(DA, HA, LTL) and types (global, per_cpu, per_task, per_obj), including
optional features like descriptions and parent monitors. Container
generation and error handling (missing files, invalid specifications,
missing arguments) are also validated against expected output.
Acked-by: Nam Cao <namcao@linutronix.de>
Reviewed-by: Wen Yang <wen.yang@linux.dev>
Link: https://lore.kernel.org/r/20260723074534.43521-9-gmonaco@redhat.com
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
The rv tool needs automated testing to catch regressions and verify
correct functionality across different usage scenarios.
Add selftests that validate monitor listing (including containers and
nested monitors), monitor execution with different configurations
(reactors, verbose output, tracing), and trace output format for both
per-task and per-cpu monitors. Error handling paths are also tested.
Tests use a shared engine for common patterns.
Acked-by: Nam Cao <namcao@linutronix.de>
Link: https://lore.kernel.org/r/20260723074534.43521-7-gmonaco@redhat.com
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
Template files for rvgen had minor inconsistencies in their
placeholders for default author and default tracepoint examples. The
user needs to modify those anyway but keeping consistency may help in
bulk editing or checking.
Change default author from "dot2k: auto-generated" (for DA/containers)
or /* TODO */ (for LTL) to the general "rvgen: auto-generated".
Align the sample tracepoint handler name in LTL template to
handle_example_event, consistently with the rest of the file.
Reviewed-by: Nam Cao <namcao@linutronix.de>
Link: https://lore.kernel.org/r/20260723074534.43521-6-gmonaco@redhat.com
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
The RVGenerator class can find the RV directory (kernel/trace/rv) in the
kernel tree to do some auto patching. This works by assuming PWD is
either the kernel tree or tools/verification, which isn't always the
case (e.g. when running from selftests).
Make discovery more robust by relying on the absolute path of the
current script and traversing backwards the right number of times.
This should work from any location if rvgen is in the kernel tree.
Reviewed-by: Nam Cao <namcao@linutronix.de>
Link: https://lore.kernel.org/r/20260723074534.43521-4-gmonaco@redhat.com
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
When running "rv mon" on a monitor that is already enabled, the tool
fails to start but incorrectly exits with a success status (0).
Fix the exit condition to ensure it returns a failure code on any
execution error. Also use the standard EXIT_SUCCESS/EXIT_FAILURE macros
throughout the file.
Reviewed-by: Nam Cao <namcao@linutronix.de>
Link: https://lore.kernel.org/r/20260723074534.43521-3-gmonaco@redhat.com
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
Add a wakeup monitor to detect a lower-priority task waking up a
higher-priority task.
The rtapp/sleep monitor already detects this. However, that monitor
triggers an error in the context of the wakee task and user only gets
the stacktrace of that task. It is also extremely useful to get the
stacktrace of the waker task, which this monitor offers. In other
words, this monitor complements the rtapp/sleep monitor.
Signed-off-by: Nam Cao <namcao@linutronix.de>
Reviewed-by: Gabriele Monaco <gmonaco@redhat.com>
Link: https://lore.kernel.org/r/ba5658fa13e49ada466b84a2c211f233037180b5.1781852967.git.namcao@linutronix.de
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
The rtapp/sleep monitor's primary purpose is detecting common mistakes
with user-space real-time design. Monitoring real-time issues with
kernel threads is a bonus.
However, accomodating kernel threads complicates the monitor due to
the edge cases which is seen by the monitor as lower-priority task
waking higher-priority task:
- kthread_stop() wakes up the task in order to stop it.
- The rcu thread and migration thread can be woken by any task.
- The ktimerd thread is woken near the end of irq_exit_rcu(), where
the preempt counter is "broken" and falsely says this is task
context. This requires the monitor to use the hardirq_context flag
instead of the preempt counter.
Beside complicating the monitor, the final case also requires enabling
CONFIG_TRACE_IRQFLAGS (so that "hardirq_context" can be used). This
adds overhead to the kernel even when the monitor is not active. This
may be an obstacle to enabling this monitor in distros' kernels.
Furthermore, kernel threads usually are started before the monitor is
enabled. Consequently, the threads' states (i.o.w. the monitor's
atomic propositions for the threads) are not fully known to the
monitor. As a result, the kernel threads mostly cannot be monitored.
Overall, the downsides of accomodating kernel threads outweights the
benefits. Thus, exclude kernel threads to simplify the monitor.
Signed-off-by: Nam Cao <namcao@linutronix.de>
Reviewed-by: Gabriele Monaco <gmonaco@redhat.com>
Link: https://lore.kernel.org/r/eec2ca5224bcdacc45b8e1eb2f0e68109e1cae7a.1781852967.git.namcao@linutronix.de
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
The rtapp/sleep monitor detects real-time tasks which go to sleep in an
real-time-unsafe manner. If this happen, the monitor triggers a trace event
in the sched_wakeup tracepoint's handler.
However, the invoking context of that trace event is not the most
informative, because of the stack trace of that event is the wakeup's code
path which is not very helpful:
74.669317: rv:error_sleep: condvar[254]: violation detected
ltl_validate+0x345 ([kernel.kallsyms])
handle_sched_wakeup+0x34 ([kernel.kallsyms])
ttwu_do_activate+0xff ([kernel.kallsyms])
sched_ttwu_pending+0x104 ([kernel.kallsyms])
__flush_smp_call_function_queue+0x15b ([kernel.kallsyms])
__sysvec_call_function_single+0x18 ([kernel.kallsyms])
sysvec_call_function_single+0x66 ([kernel.kallsyms])
asm_sysvec_call_function_single+0x1a ([kernel.kallsyms])
pv_native_safe_halt+0xf ([kernel.kallsyms])
default_idle+0x9 ([kernel.kallsyms])
default_idle_call+0x33 ([kernel.kallsyms])
do_idle+0x234 ([kernel.kallsyms])
cpu_startup_entry+0x24 ([kernel.kallsyms])
start_secondary+0xf8 ([kernel.kallsyms])
common_startup_64+0x13e ([kernel.kallsyms])
What would be much more valuable is the stack trace of the task itself.
Instead of using the sched_wakeup tracepoint, use the sched_exit
tracepoint. This makes the event happen in the task's context, making
the stack trace far more informative for user:
rv:error_sleep: condvar[254]: violation detected
ltl_validate+0x345 ([kernel.kallsyms])
handle_sched_exit+0x39 ([kernel.kallsyms])
__schedule+0x80f ([kernel.kallsyms])
schedule+0x22 ([kernel.kallsyms])
futex_do_wait+0x33 ([kernel.kallsyms])
__futex_wait+0x8c ([kernel.kallsyms])
futex_wait+0x73 ([kernel.kallsyms])
do_futex+0xc6 ([kernel.kallsyms])
__x64_sys_futex+0x121 ([kernel.kallsyms])
do_syscall_64+0xf3 ([kernel.kallsyms])
entry_SYSCALL_64_after_hwframe+0x77 ([kernel.kallsyms])
__futex_abstimed_wait_common64+0xc6 (inlined)
__futex_abstimed_wait_common+0xc6 (/usr/lib/x86_64-linux-gnu/libc.so.6)
Signed-off-by: Nam Cao <namcao@linutronix.de>
Reviewed-by: Gabriele Monaco <gmonaco@redhat.com>
Link: https://lore.kernel.org/r/d97b4b5c476e5792b6875ec9bbf8dc214f999516.1781852967.git.namcao@linutronix.de
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
Per-object monitors can allocate memory dynamically and such memory is
required for the lifetime of the object, then it should be freed with
the appropriate call.
Force the generation scripts to add a cleanup function the user will
need to wire to the appropriate event (e.g. sched_process_exit for
tasks). This can be safely removed if the object will never cease to
exist before disabling the monitor (e.g. if following only static
variables).
Reviewed-by: Nam Cao <namcao@linutronix.de>
Link: https://lore.kernel.org/r/20260601153840.124372-14-gmonaco@redhat.com
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
The DOT parsing scripts directly parse the raw text and they are quite
fragile. If the input dot files' formats are slightly changed (for
instance, by breaking long some lines which is allowed by the DOT
language), the scripts would fail.
Prepare to move away from the raw text processing, implement parsers based
on Lark which parse states, transitions and constraints.
The parse results are not used yet. The existing scripts will be converted
one by one to them, and the raw text processing will eventually be removed.
Reviewed-by: Gabriele Monaco <gmonaco@redhat.com>
Signed-off-by: Nam Cao <namcao@linutronix.de>
Link: https://lore.kernel.org/r/3ef60fdb03154abb9d9718ea106484213e1a4598.1781847583.git.namcao@linutronix.de
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
The DOT parsing scripts directly parse the raw text and they are quite
fragile. If the input dot files' formats are slightly changed (for
instance, by breaking long some lines which is allowed by the DOT language
defined by graphviz), the scripts would fail.
To make the scripts robust, the parser should be implemented based on the
dot language specification, not based on how the existing dot files look.
As a first step, use Lark to implement a Parser based on the graphviz dot
language specification. The resulting parse tree is not used yet, but the
existing scripts will be converted one by one to use this new parse tree in
the follow-up commits.
Reviewed-by: Gabriele Monaco <gmonaco@redhat.com>
Signed-off-by: Nam Cao <namcao@linutronix.de>
Link: https://lore.kernel.org/r/f816bce4cc7c48d0b6b6a28a7029459df69d6a71.1781847583.git.namcao@linutronix.de
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
The rvgen parser for LTL stores literal true values in the python
representation (capitalised True), this doesn't build in C.
The Literal class should already handle this case but ASTNode skips its
strigification method and converts the value (true/false) directly.
Fix by delegating ASTNode stringification to the Literal and Variable
classes instead of bypassing them.
Fixes: 97ffa4ce6a ("verification/rvgen: Add support for linear temporal logic")
Reviewed-by: Nam Cao <namcao@linutronix.de>
Link: https://lore.kernel.org/r/20260514152055.229162-8-gmonaco@redhat.com
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
After rvgen was refactored to use subparsers, the common options (-a and
-D) were left in the main parser. This meant that they needed to be
called /before/ the subcommand and using them without subcommand was
allowed. This is not the original intent.
rvgen -D "some description" container -n name
Define the options as parent in the subparsers to allow them to be used
from both subcommands together with other options.
rvgen container -n name -D "some description"
Fixes: 5270a0e304 ("verification/dot2k: Replace is_container() hack with subparsers")
Reviewed-by: Nam Cao <namcao@linutronix.de>
Link: https://lore.kernel.org/r/20260514152055.229162-7-gmonaco@redhat.com
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
__start_to_invariant_check() and __get_constraint_env() parse the
environment variable's name from sources that have it padded with the
monitor name. This is removed using rstrip(), which is not meant to
strip a substring but rather a set of characters.
Use removesuffix() to actually get rid of the trailing _<monitor name>.
Fixes: a82adadb16 ("verification/rvgen: Add support for Hybrid Automata")
Reviewed-by: Nam Cao <namcao@linutronix.de>
Link: https://lore.kernel.org/r/20260601153840.124372-12-gmonaco@redhat.com
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
Currently if ikm_setup_trace_instance() fails, the tool returns without
any cleanup, if rv was called with both -t and -r, this means the
reactor is not going to be cleared.
Jump to the cleanup label to restore the reactor if necessary.
Fixes: 6d60f89691 ("tools/rv: Add in-kernel monitor interface")
Reviewed-by: Nam Cao <namcao@linutronix.de>
Link: https://lore.kernel.org/r/20260514152055.229162-5-gmonaco@redhat.com
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
When listing monitors within a specific container (rv list <container>),
the tool incorrectly matched monitors if the requested container name
was only a prefix of the actual container (e.g., 'rv list sche' would
incorrectly list monitors from 'sched:').
Fix this by ensuring the container name is an exact match and is
immediately followed by the ':' separator.
Fixes: eba321a16f ("tools/rv: Add support for nested monitors")
Reviewed-by: Nam Cao <namcao@linutronix.de>
Link: https://lore.kernel.org/r/20260514152055.229162-3-gmonaco@redhat.com
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
__ikm_find_monitor_name() relies on strstr() to find a monitor by name,
which fails if the target monitor is a substring of a previously listed
monitor.
Fix it by tokenizing the available_monitors file and matching full
tokens instead.
Fixes: eba321a16f ("tools/rv: Add support for nested monitors")
Reviewed-by: Nam Cao <namcao@linutronix.de>
Link: https://lore.kernel.org/r/20260514152055.229162-2-gmonaco@redhat.com
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
ikm_fill_monitor_definition() copies monitor name and description with
strncpy(), but does not guarantee NUL termination when source strings are
equal to or longer than the destination buffers.
Clamp copies to sizeof(dst) - 1 and explicitly append '\0' for both fields
to keep them safe for later string operations.
Suggested-by: unknownbbqrx <dev@unknownbbqr.xyz>
Fixes: 6d60f89691 ("tools/rv: Add in-kernel monitor interface")
Link: https://lore.kernel.org/r/20260604120946.90302-2-gmonaco@redhat.com
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
Hybrid automata monitors may start timers, depending on the model, these
may remain active on an exiting task and cause false positives or even
access freed memory.
Add an enable/disable hook in the HA code, currently only populated by
the per-task handler for registration and deregistration.
This hooks to the sched_process_exit event and ensures the timer is
stopped for every exiting task. The handler is enabled automatically but
may be disabled, for instance if the monitor uses the event for another
purpose (but should still manually ensure timers are stopped).
Fixes: f5587d1b6e ("rv: Add Hybrid Automata monitor type")
Reviewed-by: Nam Cao <namcao@linutronix.de>
Link: https://lore.kernel.org/r/20260601153840.124372-8-gmonaco@redhat.com
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
Pyright static analysis reports a "possibly unbound variable" warning
for the loop variable `i` in the `abbreviate_atoms` function. The
variable is accessed after the inner loop terminates to slice the atom
string. While the loop logic currently ensures execution, the analyzer
flags the reliance on the loop variable persisting outside its scope.
Refactor the prefix length calculation into a nested `find_share_length`
helper function. This encapsulates the search logic and uses explicit
return statements, ensuring the length value is strictly defined. This
satisfies the type checker and improves code readability without
altering the runtime behavior.
Signed-off-by: Wander Lairson Costa <wander@redhat.com>
Reviewed-by: Gabriele Monaco <gmonaco@redhat.com>
Link: https://lore.kernel.org/r/20260223162407.147003-19-wander@redhat.com
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
The __get_state_variables() method parses DOT files to identify the
automaton's initial state. If the input file lacks a node with the
required initialization prefix, the initial_state variable is referenced
before assignment, causing an UnboundLocalError or a generic error
during the state removal step.
Initialize the variable explicitly and validate that a start node was
found after parsing. Raise a descriptive AutomataError if the definition
is missing to improve debugging and ensure the automaton is valid.
Signed-off-by: Wander Lairson Costa <wander@redhat.com>
Reviewed-by: Gabriele Monaco <gmonaco@redhat.com>
Link: https://lore.kernel.org/r/20260223162407.147003-18-wander@redhat.com
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
Add a node_marker class constant to the Automata class to replace the
hardcoded "{node" string literal used throughout the DOT file parsing
logic. This follows the existing pattern established by the init_marker
and invalid_state_str class constants in the same class.
The "{node" string is used as a marker to identify node declaration
lines in DOT files during state variable extraction and cursor
positioning. Extracting it to a named constant improves code
maintainability and makes the marker's purpose explicit.
Signed-off-by: Wander Lairson Costa <wander@redhat.com>
Reviewed-by: Gabriele Monaco <gmonaco@redhat.com>
Link: https://lore.kernel.org/r/20260223162407.147003-17-wander@redhat.com
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
The Variable.expand() method in ltl2ba.py performs contradiction
detection by checking if a negated variable already exists in the
graph node's old set. However, the isinstance check was incorrectly
testing the ASTNode wrapper instead of the wrapped operator, causing
the check to always return False.
The old set contains ASTNode instances which wrap LTL operators via
their .op attribute. The fix changes isinstance(f, NotOp) to
isinstance(f.op, NotOp) to correctly examine the wrapped operator
type. This follows the established pattern used elsewhere in the
file, such as the iteration at lines 572-574 which accesses
o.op.is_temporal() on items from node.old.
Signed-off-by: Wander Lairson Costa <wander@redhat.com>
Reviewed-by: Nam Cao <namcao@linutronix.de>
Link: https://lore.kernel.org/r/20260223162407.147003-16-wander@redhat.com
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
Add required=True to the monitor subcommand arguments for class, spec,
and monitor_type in rvgen. These arguments are essential for monitor
generation and attempting to run without them would cause AttributeError
exceptions later in the code when the script tries to access them.
Making these arguments explicitly required provides clearer error
messages to users at parse time rather than cryptic exceptions during
execution. This improves the user experience by catching missing
arguments early with helpful usage information.
Signed-off-by: Wander Lairson Costa <wander@redhat.com>
Reviewed-by: Gabriele Monaco <gmonaco@redhat.com>
Reviewed-by: Nam Cao <namcao@linutronix.de>
Link: https://lore.kernel.org/r/20260223162407.147003-15-wander@redhat.com
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
The sys module was imported in the dot2c frontend script but never
used. This import was likely left over from earlier development or
copied from a template that required sys for exit handling.
Remove the unused import to clean up the code and satisfy linters
that flag unused imports as errors.
Signed-off-by: Wander Lairson Costa <wander@redhat.com>
Reviewed-by: Gabriele Monaco <gmonaco@redhat.com>
Link: https://lore.kernel.org/r/20260223162407.147003-13-wander@redhat.com
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
Refactor the DOT file parsing logic in automata.py to use Python's
iterator-based patterns instead of manual cursor indexing. The previous
implementation relied on while loops with explicit cursor management,
which made the code prone to off-by-one errors and would crash on
malformed input files containing empty lines.
The new implementation uses enumerate and itertools.islice to iterate
over lines, eliminating manual cursor tracking. Functions that search
for specific markers now use for loops with early returns and explicit
AutomataError exceptions for missing markers, rather than assuming the
markers exist. Additional bounds checking ensures that split line
arrays have sufficient elements before accessing specific indices,
preventing IndexError exceptions on malformed DOT files.
The matrix creation and event variable extraction methods now use
functional patterns with map combined with itertools.islice,
making the intent clearer while maintaining the same behavior. Minor
improvements include using extend instead of append in a loop, adding
empty file validation, and replacing enumerate with range where the
enumerated value was unused.
Signed-off-by: Wander Lairson Costa <wander@redhat.com>
Reviewed-by: Gabriele Monaco <gmonaco@redhat.com>
Link: https://lore.kernel.org/r/20260223162407.147003-12-wander@redhat.com
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
Replace hardcoded string literal and magic number with a class
constant for the initial state marker in DOT file parsing. The
previous implementation used the magic string "__init_" directly
in the code along with a hardcoded length of 7 for substring
extraction, which made the code less maintainable and harder to
understand.
This change introduces a class constant init_marker to serve as
a single source of truth for the initial state prefix. The code
now uses startswith() for clearer intent and calculates the
substring position dynamically using len(), eliminating the magic
number. If the marker value needs to change in the future, only
the constant definition requires updating rather than multiple
locations in the code.
The refactoring improves code readability and maintainability
while preserving the exact same runtime behavior.
Signed-off-by: Wander Lairson Costa <wander@redhat.com>
Reviewed-by: Gabriele Monaco <gmonaco@redhat.com>
Reviewed-by: Nam Cao <namcao@linutronix.de>
Link: https://lore.kernel.org/r/20260223162407.147003-11-wander@redhat.com
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
Fix incorrect boolean logic in automata DOT file format validation
that allowed malformed files to pass undetected. The previous
implementation used a logical AND operator where OR was required,
causing the validation to only reject files when both the first
token was not "digraph" AND the second token was not
"state_automaton". This meant a file starting with "digraph" but
having an incorrect second token would incorrectly pass validation.
The corrected logic properly rejects DOT files where either the
first token is not "digraph" or the second token is not
"state_automaton", ensuring that only properly formatted automaton
definition files are accepted for processing. Without this fix,
invalid DOT files could cause downstream parsing failures or
generate incorrect C code for runtime verification monitors.
Signed-off-by: Wander Lairson Costa <wander@redhat.com>
Reviewed-by: Nam Cao <namcao@linutronix.de>
Reviewed-by: Gabriele Monaco <gmonaco@redhat.com>
Link: https://lore.kernel.org/r/20260223162407.147003-10-wander@redhat.com
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
Fix whitespace violations throughout the rvgen codebase to comply
with PEP 8 style guidelines. The changes address missing whitespace
after commas, around operators, and in collection literals that
were flagged by pycodestyle.
The fixes include adding whitespace after commas in string replace
chains and function arguments, adding whitespace around arithmetic
operators, removing extra whitespace in list comprehensions, and
fixing dictionary literal spacing. These changes improve code
readability and consistency with Python coding standards.
Signed-off-by: Wander Lairson Costa <wander@redhat.com>
Reviewed-by: Gabriele Monaco <gmonaco@redhat.com>
Reviewed-by: Nam Cao <namcao@linutronix.de>
Link: https://lore.kernel.org/r/20260223162407.147003-9-wander@redhat.com
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
Gabriele Monaco