Tracing updates for 5.20 / 6.0

- Runtime verification infrastructure
   This is the biggest change for this pull request. It introduces the
   runtime verification that is necessary for running Linux on safety
   critical systems. It allows for deterministic automata models to be
   inserted into the kernel that will attach to tracepoints, where the
   information on these tracepoints will move the model from state to state.
   If a state is encountered that does not belong to the model, it will then
   activate a given reactor, that could just inform the user or even panic
   the kernel (for which safety critical systems will detect and can recover
   from).
 
 - Two monitor models are also added: Wakeup In Preemptive (WIP - not to be
   confused with "work in progress"), and Wakeup While Not Running (WWNR).
 
 - Added __vstring() helper to the TRACE_EVENT() macro to replace several
   vsnprintf() usages that were all doing it wrong.
 
 - eprobes now can have their event autogenerated when the event name is left
   off.
 
 - The rest is various cleanups and fixes.
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Merge tag 'trace-v6.0' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing updates from Steven Rostedt:

 - Runtime verification infrastructure

   This is the biggest change here. It introduces the runtime
   verification that is necessary for running Linux on safety critical
   systems.

   It allows for deterministic automata models to be inserted into the
   kernel that will attach to tracepoints, where the information on
   these tracepoints will move the model from state to state.

   If a state is encountered that does not belong to the model, it will
   then activate a given reactor, that could just inform the user or
   even panic the kernel (for which safety critical systems will detect
   and can recover from).

 - Two monitor models are also added: Wakeup In Preemptive (WIP - not to
   be confused with "work in progress"), and Wakeup While Not Running
   (WWNR).

 - Added __vstring() helper to the TRACE_EVENT() macro to replace
   several vsnprintf() usages that were all doing it wrong.

 - eprobes now can have their event autogenerated when the event name is
   left off.

 - The rest is various cleanups and fixes.

* tag 'trace-v6.0' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (50 commits)
  rv: Unlock on error path in rv_unregister_reactor()
  tracing: Use alignof__(struct {type b;}) instead of offsetof()
  tracing/eprobe: Show syntax error logs in error_log file
  scripts/tracing: Fix typo 'the the' in comment
  tracepoints: It is CONFIG_TRACEPOINTS not CONFIG_TRACEPOINT
  tracing: Use free_trace_buffer() in allocate_trace_buffers()
  tracing: Use a struct alignof to determine trace event field alignment
  rv/reactor: Add the panic reactor
  rv/reactor: Add the printk reactor
  rv/monitor: Add the wwnr monitor
  rv/monitor: Add the wip monitor
  rv/monitor: Add the wip monitor skeleton created by dot2k
  Documentation/rv: Add deterministic automata instrumentation documentation
  Documentation/rv: Add deterministic automata monitor synthesis documentation
  tools/rv: Add dot2k
  Documentation/rv: Add deterministic automaton documentation
  tools/rv: Add dot2c
  Documentation/rv: Add a basic documentation
  rv/include: Add instrumentation helper functions
  rv/include: Add deterministic automata monitor definition via C macros
  ...
This commit is contained in:
Linus Torvalds 2022-08-05 09:41:12 -07:00
commit 965a9d75e3
86 changed files with 4808 additions and 172 deletions

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@ -32,3 +32,4 @@ Linux Tracing Technologies
sys-t
coresight/index
user_events
rv/index

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@ -28,10 +28,10 @@ Synopsis of kprobe_events
-------------------------
::
p[:[GRP/]EVENT] [MOD:]SYM[+offs]|MEMADDR [FETCHARGS] : Set a probe
r[MAXACTIVE][:[GRP/]EVENT] [MOD:]SYM[+0] [FETCHARGS] : Set a return probe
p:[GRP/]EVENT] [MOD:]SYM[+0]%return [FETCHARGS] : Set a return probe
-:[GRP/]EVENT : Clear a probe
p[:[GRP/][EVENT]] [MOD:]SYM[+offs]|MEMADDR [FETCHARGS] : Set a probe
r[MAXACTIVE][:[GRP/][EVENT]] [MOD:]SYM[+0] [FETCHARGS] : Set a return probe
p[:[GRP/][EVENT]] [MOD:]SYM[+0]%return [FETCHARGS] : Set a return probe
-:[GRP/][EVENT] : Clear a probe
GRP : Group name. If omitted, use "kprobes" for it.
EVENT : Event name. If omitted, the event name is generated

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@ -0,0 +1,171 @@
Deterministic Automata Instrumentation
======================================
The RV monitor file created by dot2k, with the name "$MODEL_NAME.c"
includes a section dedicated to instrumentation.
In the example of the wip.dot monitor created on [1], it will look like::
/*
* This is the instrumentation part of the monitor.
*
* This is the section where manual work is required. Here the kernel events
* are translated into model's event.
*
*/
static void handle_preempt_disable(void *data, /* XXX: fill header */)
{
da_handle_event_wip(preempt_disable_wip);
}
static void handle_preempt_enable(void *data, /* XXX: fill header */)
{
da_handle_event_wip(preempt_enable_wip);
}
static void handle_sched_waking(void *data, /* XXX: fill header */)
{
da_handle_event_wip(sched_waking_wip);
}
static int enable_wip(void)
{
int retval;
retval = da_monitor_init_wip();
if (retval)
return retval;
rv_attach_trace_probe("wip", /* XXX: tracepoint */, handle_preempt_disable);
rv_attach_trace_probe("wip", /* XXX: tracepoint */, handle_preempt_enable);
rv_attach_trace_probe("wip", /* XXX: tracepoint */, handle_sched_waking);
return 0;
}
The comment at the top of the section explains the general idea: the
instrumentation section translates *kernel events* into the *model's
event*.
Tracing callback functions
--------------------------
The first three functions are the starting point of the callback *handler
functions* for each of the three events from the wip model. The developer
does not necessarily need to use them: they are just starting points.
Using the example of::
void handle_preempt_disable(void *data, /* XXX: fill header */)
{
da_handle_event_wip(preempt_disable_wip);
}
The preempt_disable event from the model connects directly to the
preemptirq:preempt_disable. The preemptirq:preempt_disable event
has the following signature, from include/trace/events/preemptirq.h::
TP_PROTO(unsigned long ip, unsigned long parent_ip)
Hence, the handle_preempt_disable() function will look like::
void handle_preempt_disable(void *data, unsigned long ip, unsigned long parent_ip)
In this case, the kernel event translates one to one with the automata
event, and indeed, no other change is required for this function.
The next handler function, handle_preempt_enable() has the same argument
list from the handle_preempt_disable(). The difference is that the
preempt_enable event will be used to synchronize the system to the model.
Initially, the *model* is placed in the initial state. However, the *system*
might or might not be in the initial state. The monitor cannot start
processing events until it knows that the system has reached the initial state.
Otherwise, the monitor and the system could be out-of-sync.
Looking at the automata definition, it is possible to see that the system
and the model are expected to return to the initial state after the
preempt_enable execution. Hence, it can be used to synchronize the
system and the model at the initialization of the monitoring section.
The start is informed via a special handle function, the
"da_handle_start_event_$(MONITOR_NAME)(event)", in this case::
da_handle_start_event_wip(preempt_enable_wip);
So, the callback function will look like::
void handle_preempt_enable(void *data, unsigned long ip, unsigned long parent_ip)
{
da_handle_start_event_wip(preempt_enable_wip);
}
Finally, the "handle_sched_waking()" will look like::
void handle_sched_waking(void *data, struct task_struct *task)
{
da_handle_event_wip(sched_waking_wip);
}
And the explanation is left for the reader as an exercise.
enable and disable functions
----------------------------
dot2k automatically creates two special functions::
enable_$(MONITOR_NAME)()
disable_$(MONITOR_NAME)()
These functions are called when the monitor is enabled and disabled,
respectively.
They should be used to *attach* and *detach* the instrumentation to the running
system. The developer must add to the relative function all that is needed to
*attach* and *detach* its monitor to the system.
For the wip case, these functions were named::
enable_wip()
disable_wip()
But no change was required because: by default, these functions *attach* and
*detach* the tracepoints_to_attach, which was enough for this case.
Instrumentation helpers
-----------------------
To complete the instrumentation, the *handler functions* need to be attached to a
kernel event, at the monitoring enable phase.
The RV interface also facilitates this step. For example, the macro "rv_attach_trace_probe()"
is used to connect the wip model events to the relative kernel event. dot2k automatically
adds "rv_attach_trace_probe()" function call for each model event in the enable phase, as
a suggestion.
For example, from the wip sample model::
static int enable_wip(void)
{
int retval;
retval = da_monitor_init_wip();
if (retval)
return retval;
rv_attach_trace_probe("wip", /* XXX: tracepoint */, handle_preempt_enable);
rv_attach_trace_probe("wip", /* XXX: tracepoint */, handle_sched_waking);
rv_attach_trace_probe("wip", /* XXX: tracepoint */, handle_preempt_disable);
return 0;
}
The probes then need to be detached at the disable phase.
[1] The wip model is presented in::
Documentation/trace/rv/deterministic_automata.rst
The wip monitor is presented in::
Documentation/trace/rv/da_monitor_synthesis.rst

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Deterministic Automata Monitor Synthesis
========================================
The starting point for the application of runtime verification (RV) technics
is the *specification* or *modeling* of the desired (or undesired) behavior
of the system under scrutiny.
The formal representation needs to be then *synthesized* into a *monitor*
that can then be used in the analysis of the trace of the system. The
*monitor* connects to the system via an *instrumentation* that converts
the events from the *system* to the events of the *specification*.
In Linux terms, the runtime verification monitors are encapsulated inside
the *RV monitor* abstraction. The RV monitor includes a set of instances
of the monitor (per-cpu monitor, per-task monitor, and so on), the helper
functions that glue the monitor to the system reference model, and the
trace output as a reaction to event parsing and exceptions, as depicted
below::
Linux +----- RV Monitor ----------------------------------+ Formal
Realm | | Realm
+-------------------+ +----------------+ +-----------------+
| Linux kernel | | Monitor | | Reference |
| Tracing | -> | Instance(s) | <- | Model |
| (instrumentation) | | (verification) | | (specification) |
+-------------------+ +----------------+ +-----------------+
| | |
| V |
| +----------+ |
| | Reaction | |
| +--+--+--+-+ |
| | | | |
| | | +-> trace output ? |
+------------------------|--|----------------------+
| +----> panic ?
+-------> <user-specified>
DA monitor synthesis
--------------------
The synthesis of automata-based models into the Linux *RV monitor* abstraction
is automated by the dot2k tool and the rv/da_monitor.h header file that
contains a set of macros that automatically generate the monitor's code.
dot2k
-----
The dot2k utility leverages dot2c by converting an automaton model in
the DOT format into the C representation [1] and creating the skeleton of
a kernel monitor in C.
For example, it is possible to transform the wip.dot model present in
[1] into a per-cpu monitor with the following command::
$ dot2k -d wip.dot -t per_cpu
This will create a directory named wip/ with the following files:
- wip.h: the wip model in C
- wip.c: the RV monitor
The wip.c file contains the monitor declaration and the starting point for
the system instrumentation.
Monitor macros
--------------
The rv/da_monitor.h enables automatic code generation for the *Monitor
Instance(s)* using C macros.
The benefits of the usage of macro for monitor synthesis are 3-fold as it:
- Reduces the code duplication;
- Facilitates the bug fix/improvement;
- Avoids the case of developers changing the core of the monitor code
to manipulate the model in a (let's say) non-standard way.
This initial implementation presents three different types of monitor instances:
- ``#define DECLARE_DA_MON_GLOBAL(name, type)``
- ``#define DECLARE_DA_MON_PER_CPU(name, type)``
- ``#define DECLARE_DA_MON_PER_TASK(name, type)``
The first declares the functions for a global deterministic automata monitor,
the second for monitors with per-cpu instances, and the third with per-task
instances.
In all cases, the 'name' argument is a string that identifies the monitor, and
the 'type' argument is the data type used by dot2k on the representation of
the model in C.
For example, the wip model with two states and three events can be
stored in an 'unsigned char' type. Considering that the preemption control
is a per-cpu behavior, the monitor declaration in the 'wip.c' file is::
DECLARE_DA_MON_PER_CPU(wip, unsigned char);
The monitor is executed by sending events to be processed via the functions
presented below::
da_handle_event_$(MONITOR_NAME)($(event from event enum));
da_handle_start_event_$(MONITOR_NAME)($(event from event enum));
da_handle_start_run_event_$(MONITOR_NAME)($(event from event enum));
The function ``da_handle_event_$(MONITOR_NAME)()`` is the regular case where
the event will be processed if the monitor is processing events.
When a monitor is enabled, it is placed in the initial state of the automata.
However, the monitor does not know if the system is in the *initial state*.
The ``da_handle_start_event_$(MONITOR_NAME)()`` function is used to notify the
monitor that the system is returning to the initial state, so the monitor can
start monitoring the next event.
The ``da_handle_start_run_event_$(MONITOR_NAME)()`` function is used to notify
the monitor that the system is known to be in the initial state, so the
monitor can start monitoring and monitor the current event.
Using the wip model as example, the events "preempt_disable" and
"sched_waking" should be sent to monitor, respectively, via [2]::
da_handle_event_wip(preempt_disable_wip);
da_handle_event_wip(sched_waking_wip);
While the event "preempt_enabled" will use::
da_handle_start_event_wip(preempt_enable_wip);
To notify the monitor that the system will be returning to the initial state,
so the system and the monitor should be in sync.
Final remarks
-------------
With the monitor synthesis in place using the rv/da_monitor.h and
dot2k, the developer's work should be limited to the instrumentation
of the system, increasing the confidence in the overall approach.
[1] For details about deterministic automata format and the translation
from one representation to another, see::
Documentation/trace/rv/deterministic_automata.rst
[2] dot2k appends the monitor's name suffix to the events enums to
avoid conflicting variables when exporting the global vmlinux.h
use by BPF programs.

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Deterministic Automata
======================
Formally, a deterministic automaton, denoted by G, is defined as a quintuple:
*G* = { *X*, *E*, *f*, x\ :subscript:`0`, X\ :subscript:`m` }
where:
- *X* is the set of states;
- *E* is the finite set of events;
- x\ :subscript:`0` is the initial state;
- X\ :subscript:`m` (subset of *X*) is the set of marked (or final) states.
- *f* : *X* x *E* -> *X* $ is the transition function. It defines the state
transition in the occurrence of an event from *E* in the state *X*. In the
special case of deterministic automata, the occurrence of the event in *E*
in a state in *X* has a deterministic next state from *X*.
For example, a given automaton named 'wip' (wakeup in preemptive) can
be defined as:
- *X* = { ``preemptive``, ``non_preemptive``}
- *E* = { ``preempt_enable``, ``preempt_disable``, ``sched_waking``}
- x\ :subscript:`0` = ``preemptive``
- X\ :subscript:`m` = {``preemptive``}
- *f* =
- *f*\ (``preemptive``, ``preempt_disable``) = ``non_preemptive``
- *f*\ (``non_preemptive``, ``sched_waking``) = ``non_preemptive``
- *f*\ (``non_preemptive``, ``preempt_enable``) = ``preemptive``
One of the benefits of this formal definition is that it can be presented
in multiple formats. For example, using a *graphical representation*, using
vertices (nodes) and edges, which is very intuitive for *operating system*
practitioners, without any loss.
The previous 'wip' automaton can also be represented as::
preempt_enable
+---------------------------------+
v |
#============# preempt_disable +------------------+
--> H preemptive H -----------------> | non_preemptive |
#============# +------------------+
^ |
| sched_waking |
+--------------+
Deterministic Automaton in C
----------------------------
In the paper "Efficient formal verification for the Linux kernel",
the authors present a simple way to represent an automaton in C that can
be used as regular code in the Linux kernel.
For example, the 'wip' automata can be presented as (augmented with comments)::
/* enum representation of X (set of states) to be used as index */
enum states {
preemptive = 0,
non_preemptive,
state_max
};
#define INVALID_STATE state_max
/* enum representation of E (set of events) to be used as index */
enum events {
preempt_disable = 0,
preempt_enable,
sched_waking,
event_max
};
struct automaton {
char *state_names[state_max]; // X: the set of states
char *event_names[event_max]; // E: the finite set of events
unsigned char function[state_max][event_max]; // f: transition function
unsigned char initial_state; // x_0: the initial state
bool final_states[state_max]; // X_m: the set of marked states
};
struct automaton aut = {
.state_names = {
"preemptive",
"non_preemptive"
},
.event_names = {
"preempt_disable",
"preempt_enable",
"sched_waking"
},
.function = {
{ non_preemptive, INVALID_STATE, INVALID_STATE },
{ INVALID_STATE, preemptive, non_preemptive },
},
.initial_state = preemptive,
.final_states = { 1, 0 },
};
The *transition function* is represented as a matrix of states (lines) and
events (columns), and so the function *f* : *X* x *E* -> *X* can be solved
in O(1). For example::
next_state = automaton_wip.function[curr_state][event];
Graphviz .dot format
--------------------
The Graphviz open-source tool can produce the graphical representation
of an automaton using the (textual) DOT language as the source code.
The DOT format is widely used and can be converted to many other formats.
For example, this is the 'wip' model in DOT::
digraph state_automaton {
{node [shape = circle] "non_preemptive"};
{node [shape = plaintext, style=invis, label=""] "__init_preemptive"};
{node [shape = doublecircle] "preemptive"};
{node [shape = circle] "preemptive"};
"__init_preemptive" -> "preemptive";
"non_preemptive" [label = "non_preemptive"];
"non_preemptive" -> "non_preemptive" [ label = "sched_waking" ];
"non_preemptive" -> "preemptive" [ label = "preempt_enable" ];
"preemptive" [label = "preemptive"];
"preemptive" -> "non_preemptive" [ label = "preempt_disable" ];
{ rank = min ;
"__init_preemptive";
"preemptive";
}
}
This DOT format can be transformed into a bitmap or vectorial image
using the dot utility, or into an ASCII art using graph-easy. For
instance::
$ dot -Tsvg -o wip.svg wip.dot
$ graph-easy wip.dot > wip.txt
dot2c
-----
dot2c is a utility that can parse a .dot file containing an automaton as
in the example above and automatically convert it to the C representation
presented in [3].
For example, having the previous 'wip' model into a file named 'wip.dot',
the following command will transform the .dot file into the C
representation (previously shown) in the 'wip.h' file::
$ dot2c wip.dot > wip.h
The 'wip.h' content is the code sample in section 'Deterministic Automaton
in C'.
Remarks
-------
The automata formalism allows modeling discrete event systems (DES) in
multiple formats, suitable for different applications/users.
For example, the formal description using set theory is better suitable
for automata operations, while the graphical format for human interpretation;
and computer languages for machine execution.
References
----------
Many textbooks cover automata formalism. For a brief introduction see::
O'Regan, Gerard. Concise guide to software engineering. Springer,
Cham, 2017.
For a detailed description, including operations, and application on Discrete
Event Systems (DES), see::
Cassandras, Christos G., and Stephane Lafortune, eds. Introduction to discrete
event systems. Boston, MA: Springer US, 2008.
For the C representation in kernel, see::
De Oliveira, Daniel Bristot; Cucinotta, Tommaso; De Oliveira, Romulo
Silva. Efficient formal verification for the Linux kernel. In:
International Conference on Software Engineering and Formal Methods.
Springer, Cham, 2019. p. 315-332.

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====================
Runtime Verification
====================
.. toctree::
:maxdepth: 2
:glob:
runtime-verification.rst
deterministic_automata.rst
da_monitor_synthesis.rst
da_monitor_instrumentation.rst
monitor_wip.rst
monitor_wwnr.rst

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Monitor wip
===========
- Name: wip - wakeup in preemptive
- Type: per-cpu deterministic automaton
- Author: Daniel Bristot de Oliveira <bristot@kernel.org>
Description
-----------
The wakeup in preemptive (wip) monitor is a sample per-cpu monitor
that verifies if the wakeup events always take place with
preemption disabled::
|
|
v
#==================#
H preemptive H <+
#==================# |
| |
| preempt_disable | preempt_enable
v |
sched_waking +------------------+ |
+--------------- | | |
| | non_preemptive | |
+--------------> | | -+
+------------------+
The wakeup event always takes place with preemption disabled because
of the scheduler synchronization. However, because the preempt_count
and its trace event are not atomic with regard to interrupts, some
inconsistencies might happen. For example::
preempt_disable() {
__preempt_count_add(1)
-------> smp_apic_timer_interrupt() {
preempt_disable()
do not trace (preempt count >= 1)
wake up a thread
preempt_enable()
do not trace (preempt count >= 1)
}
<------
trace_preempt_disable();
}
This problem was reported and discussed here:
https://lore.kernel.org/r/cover.1559051152.git.bristot@redhat.com/
Specification
-------------
Grapviz Dot file in tools/verification/models/wip.dot

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Monitor wwnr
============
- Name: wwrn - wakeup while not running
- Type: per-task deterministic automaton
- Author: Daniel Bristot de Oliveira <bristot@kernel.org>
Description
-----------
This is a per-task sample monitor, with the following
definition::
|
|
v
wakeup +-------------+
+--------- | |
| | not_running |
+--------> | | <+
+-------------+ |
| |
| switch_in | switch_out
v |
+-------------+ |
| running | -+
+-------------+
This model is borken, the reason is that a task can be running
in the processor without being set as RUNNABLE. Think about a
task about to sleep::
1: set_current_state(TASK_UNINTERRUPTIBLE);
2: schedule();
And then imagine an IRQ happening in between the lines one and two,
waking the task up. BOOM, the wakeup will happen while the task is
running.
- Why do we need this model, so?
- To test the reactors.
Specification
-------------
Grapviz Dot file in tools/verification/models/wwnr.dot

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====================
Runtime Verification
====================
Runtime Verification (RV) is a lightweight (yet rigorous) method that
complements classical exhaustive verification techniques (such as *model
checking* and *theorem proving*) with a more practical approach for complex
systems.
Instead of relying on a fine-grained model of a system (e.g., a
re-implementation a instruction level), RV works by analyzing the trace of the
system's actual execution, comparing it against a formal specification of
the system behavior.
The main advantage is that RV can give precise information on the runtime
behavior of the monitored system, without the pitfalls of developing models
that require a re-implementation of the entire system in a modeling language.
Moreover, given an efficient monitoring method, it is possible execute an
*online* verification of a system, enabling the *reaction* for unexpected
events, avoiding, for example, the propagation of a failure on safety-critical
systems.
Runtime Monitors and Reactors
=============================
A monitor is the central part of the runtime verification of a system. The
monitor stands in between the formal specification of the desired (or
undesired) behavior, and the trace of the actual system.
In Linux terms, the runtime verification monitors are encapsulated inside the
*RV monitor* abstraction. A *RV monitor* includes a reference model of the
system, a set of instances of the monitor (per-cpu monitor, per-task monitor,
and so on), and the helper functions that glue the monitor to the system via
trace, as depicted bellow::
Linux +---- RV Monitor ----------------------------------+ Formal
Realm | | Realm
+-------------------+ +----------------+ +-----------------+
| Linux kernel | | Monitor | | Reference |
| Tracing | -> | Instance(s) | <- | Model |
| (instrumentation) | | (verification) | | (specification) |
+-------------------+ +----------------+ +-----------------+
| | |
| V |
| +----------+ |
| | Reaction | |
| +--+--+--+-+ |
| | | | |
| | | +-> trace output ? |
+------------------------|--|----------------------+
| +----> panic ?
+-------> <user-specified>
In addition to the verification and monitoring of the system, a monitor can
react to an unexpected event. The forms of reaction can vary from logging the
event occurrence to the enforcement of the correct behavior to the extreme
action of taking a system down to avoid the propagation of a failure.
In Linux terms, a *reactor* is an reaction method available for *RV monitors*.
By default, all monitors should provide a trace output of their actions,
which is already a reaction. In addition, other reactions will be available
so the user can enable them as needed.
For further information about the principles of runtime verification and
RV applied to Linux:
Bartocci, Ezio, et al. *Introduction to runtime verification.* In: Lectures on
Runtime Verification. Springer, Cham, 2018. p. 1-33.
Falcone, Ylies, et al. *A taxonomy for classifying runtime verification tools.*
In: International Conference on Runtime Verification. Springer, Cham, 2018. p.
241-262.
De Oliveira, Daniel Bristot. *Automata-based formal analysis and
verification of the real-time Linux kernel.* Ph.D. Thesis, 2020.
Online RV monitors
==================
Monitors can be classified as *offline* and *online* monitors. *Offline*
monitor process the traces generated by a system after the events, generally by
reading the trace execution from a permanent storage system. *Online* monitors
process the trace during the execution of the system. Online monitors are said
to be *synchronous* if the processing of an event is attached to the system
execution, blocking the system during the event monitoring. On the other hand,
an *asynchronous* monitor has its execution detached from the system. Each type
of monitor has a set of advantages. For example, *offline* monitors can be
executed on different machines but require operations to save the log to a
file. In contrast, *synchronous online* method can react at the exact moment
a violation occurs.
Another important aspect regarding monitors is the overhead associated with the
event analysis. If the system generates events at a frequency higher than the
monitor's ability to process them in the same system, only the *offline*
methods are viable. On the other hand, if the tracing of the events incurs
on higher overhead than the simple handling of an event by a monitor, then a
*synchronous online* monitors will incur on lower overhead.
Indeed, the research presented in:
De Oliveira, Daniel Bristot; Cucinotta, Tommaso; De Oliveira, Romulo Silva.
*Efficient formal verification for the Linux kernel.* In: International
Conference on Software Engineering and Formal Methods. Springer, Cham, 2019.
p. 315-332.
Shows that for Deterministic Automata models, the synchronous processing of
events in-kernel causes lower overhead than saving the same events to the trace
buffer, not even considering collecting the trace for user-space analysis.
This motivated the development of an in-kernel interface for online monitors.
For further information about modeling of Linux kernel behavior using automata,
see:
De Oliveira, Daniel B.; De Oliveira, Romulo S.; Cucinotta, Tommaso. *A thread
synchronization model for the PREEMPT_RT Linux kernel.* Journal of Systems
Architecture, 2020, 107: 101729.
The user interface
==================
The user interface resembles the tracing interface (on purpose). It is
currently at "/sys/kernel/tracing/rv/".
The following files/folders are currently available:
**available_monitors**
- Reading list the available monitors, one per line
For example::
# cat available_monitors
wip
wwnr
**available_reactors**
- Reading shows the available reactors, one per line.
For example::
# cat available_reactors
nop
panic
printk
**enabled_monitors**:
- Reading lists the enabled monitors, one per line
- Writing to it enables a given monitor
- Writing a monitor name with a '!' prefix disables it
- Truncating the file disables all enabled monitors
For example::
# cat enabled_monitors
# echo wip > enabled_monitors
# echo wwnr >> enabled_monitors
# cat enabled_monitors
wip
wwnr
# echo '!wip' >> enabled_monitors
# cat enabled_monitors
wwnr
# echo > enabled_monitors
# cat enabled_monitors
#
Note that it is possible to enable more than one monitor concurrently.
**monitoring_on**
This is an on/off general switcher for monitoring. It resembles the
"tracing_on" switcher in the trace interface.
- Writing "0" stops the monitoring
- Writing "1" continues the monitoring
- Reading returns the current status of the monitoring
Note that it does not disable enabled monitors but stop the per-entity
monitors monitoring the events received from the system.
**reacting_on**
- Writing "0" prevents reactions for happening
- Writing "1" enable reactions
- Reading returns the current status of the reaction
**monitors/**
Each monitor will have its own directory inside "monitors/". There the
monitor-specific files will be presented. The "monitors/" directory resembles
the "events" directory on tracefs.
For example::
# cd monitors/wip/
# ls
desc enable
# cat desc
wakeup in preemptive per-cpu testing monitor.
# cat enable
0
**monitors/MONITOR/desc**
- Reading shows a description of the monitor *MONITOR*
**monitors/MONITOR/enable**
- Writing "0" disables the *MONITOR*
- Writing "1" enables the *MONITOR*
- Reading return the current status of the *MONITOR*
**monitors/MONITOR/reactors**
- List available reactors, with the select reaction for the given *MONITOR*
inside "[]". The default one is the nop (no operation) reactor.
- Writing the name of a reactor enables it to the given MONITOR.
For example::
# cat monitors/wip/reactors
[nop]
panic
printk
# echo panic > monitors/wip/reactors
# cat monitors/wip/reactors
nop
[panic]
printk

View File

@ -26,10 +26,10 @@ Synopsis of uprobe_tracer
-------------------------
::
p[:[GRP/]EVENT] PATH:OFFSET [FETCHARGS] : Set a uprobe
r[:[GRP/]EVENT] PATH:OFFSET [FETCHARGS] : Set a return uprobe (uretprobe)
p[:[GRP/]EVENT] PATH:OFFSET%return [FETCHARGS] : Set a return uprobe (uretprobe)
-:[GRP/]EVENT : Clear uprobe or uretprobe event
p[:[GRP/][EVENT]] PATH:OFFSET [FETCHARGS] : Set a uprobe
r[:[GRP/][EVENT]] PATH:OFFSET [FETCHARGS] : Set a return uprobe (uretprobe)
p[:[GRP/][EVENT]] PATH:OFFSET%return [FETCHARGS] : Set a return uprobe (uretprobe)
-:[GRP/][EVENT] : Clear uprobe or uretprobe event
GRP : Group name. If omitted, "uprobes" is the default value.
EVENT : Event name. If omitted, the event name is generated based

View File

@ -91,6 +91,7 @@ static int ftrace_verify_code(unsigned long ip, const char *old_code)
/* Make sure it is what we expect it to be */
if (memcmp(cur_code, old_code, MCOUNT_INSN_SIZE) != 0) {
ftrace_expected = old_code;
WARN_ON(1);
return -EINVAL;
}

View File

@ -26,14 +26,10 @@ DECLARE_EVENT_CLASS(hfi1_trace_template,
TP_PROTO(const char *function, struct va_format *vaf),
TP_ARGS(function, vaf),
TP_STRUCT__entry(__string(function, function)
__dynamic_array(char, msg, MAX_MSG_LEN)
__vstring(msg, vaf->fmt, vaf->va)
),
TP_fast_assign(__assign_str(function, function);
WARN_ON_ONCE(vsnprintf
(__get_dynamic_array(msg),
MAX_MSG_LEN, vaf->fmt,
*vaf->va) >=
MAX_MSG_LEN);
__assign_vstr(msg, vaf->fmt, vaf->va);
),
TP_printk("(%s) %s",
__get_str(function),

View File

@ -52,15 +52,12 @@ DECLARE_EVENT_CLASS(ath10k_log_event,
TP_STRUCT__entry(
__string(device, dev_name(ar->dev))
__string(driver, dev_driver_string(ar->dev))
__dynamic_array(char, msg, ATH10K_MSG_MAX)
__vstring(msg, vaf->fmt, vaf->va)
),
TP_fast_assign(
__assign_str(device, dev_name(ar->dev));
__assign_str(driver, dev_driver_string(ar->dev));
WARN_ON_ONCE(vsnprintf(__get_dynamic_array(msg),
ATH10K_MSG_MAX,
vaf->fmt,
*vaf->va) >= ATH10K_MSG_MAX);
__assign_vstr(msg, vaf->fmt, vaf->va);
),
TP_printk(
"%s %s %s",
@ -92,16 +89,13 @@ TRACE_EVENT(ath10k_log_dbg,
__string(device, dev_name(ar->dev))
__string(driver, dev_driver_string(ar->dev))
__field(unsigned int, level)
__dynamic_array(char, msg, ATH10K_MSG_MAX)
__vstring(msg, vaf->fmt, vaf->va)
),
TP_fast_assign(
__assign_str(device, dev_name(ar->dev));
__assign_str(driver, dev_driver_string(ar->dev));
__entry->level = level;
WARN_ON_ONCE(vsnprintf(__get_dynamic_array(msg),
ATH10K_MSG_MAX,
vaf->fmt,
*vaf->va) >= ATH10K_MSG_MAX);
__assign_vstr(msg, vaf->fmt, vaf->va);
),
TP_printk(
"%s %s %s",

View File

@ -126,15 +126,12 @@ DECLARE_EVENT_CLASS(ath11k_log_event,
TP_STRUCT__entry(
__string(device, dev_name(ab->dev))
__string(driver, dev_driver_string(ab->dev))
__dynamic_array(char, msg, ATH11K_MSG_MAX)
__vstring(msg, vaf->fmt, vaf->va)
),
TP_fast_assign(
__assign_str(device, dev_name(ab->dev));
__assign_str(driver, dev_driver_string(ab->dev));
WARN_ON_ONCE(vsnprintf(__get_dynamic_array(msg),
ATH11K_MSG_MAX,
vaf->fmt,
*vaf->va) >= ATH11K_MSG_MAX);
__assign_vstr(msg, vaf->fmt, vaf->va);
),
TP_printk(
"%s %s %s",

View File

@ -253,13 +253,10 @@ DECLARE_EVENT_CLASS(ath6kl_log_event,
TP_PROTO(struct va_format *vaf),
TP_ARGS(vaf),
TP_STRUCT__entry(
__dynamic_array(char, msg, ATH6KL_MSG_MAX)
__vstring(msg, vaf->fmt, vaf->va)
),
TP_fast_assign(
WARN_ON_ONCE(vsnprintf(__get_dynamic_array(msg),
ATH6KL_MSG_MAX,
vaf->fmt,
*vaf->va) >= ATH6KL_MSG_MAX);
__assign_vstr(msg, vaf->fmt, vaf->va);
),
TP_printk("%s", __get_str(msg))
);
@ -284,14 +281,11 @@ TRACE_EVENT(ath6kl_log_dbg,
TP_ARGS(level, vaf),
TP_STRUCT__entry(
__field(unsigned int, level)
__dynamic_array(char, msg, ATH6KL_MSG_MAX)
__vstring(msg, vaf->fmt, vaf->va)
),
TP_fast_assign(
__entry->level = level;
WARN_ON_ONCE(vsnprintf(__get_dynamic_array(msg),
ATH6KL_MSG_MAX,
vaf->fmt,
*vaf->va) >= ATH6KL_MSG_MAX);
__assign_vstr(msg, vaf->fmt, vaf->va);
),
TP_printk("%s", __get_str(msg))
);

View File

@ -40,16 +40,13 @@ TRACE_EVENT(ath_log,
TP_STRUCT__entry(
__string(device, wiphy_name(wiphy))
__string(driver, KBUILD_MODNAME)
__dynamic_array(char, msg, ATH_DBG_MAX_LEN)
__vstring(msg, vaf->fmt, vaf->va)
),
TP_fast_assign(
__assign_str(device, wiphy_name(wiphy));
__assign_str(driver, KBUILD_MODNAME);
WARN_ON_ONCE(vsnprintf(__get_dynamic_array(msg),
ATH_DBG_MAX_LEN,
vaf->fmt,
*vaf->va) >= ATH_DBG_MAX_LEN);
__assign_vstr(msg, vaf->fmt, vaf->va);
),
TP_printk(

View File

@ -70,13 +70,10 @@ DECLARE_EVENT_CLASS(wil6210_log_event,
TP_PROTO(struct va_format *vaf),
TP_ARGS(vaf),
TP_STRUCT__entry(
__dynamic_array(char, msg, WIL6210_MSG_MAX)
__vstring(msg, vaf->fmt, vaf->va)
),
TP_fast_assign(
WARN_ON_ONCE(vsnprintf(__get_dynamic_array(msg),
WIL6210_MSG_MAX,
vaf->fmt,
*vaf->va) >= WIL6210_MSG_MAX);
__assign_vstr(msg, vaf->fmt, vaf->va);
),
TP_printk("%s", __get_str(msg))
);

View File

@ -33,13 +33,11 @@ TRACE_EVENT(brcmf_err,
TP_ARGS(func, vaf),
TP_STRUCT__entry(
__string(func, func)
__dynamic_array(char, msg, MAX_MSG_LEN)
__vstring(msg, vaf->fmt, vaf->va)
),
TP_fast_assign(
__assign_str(func, func);
WARN_ON_ONCE(vsnprintf(__get_dynamic_array(msg),
MAX_MSG_LEN, vaf->fmt,
*vaf->va) >= MAX_MSG_LEN);
__assign_vstr(msg, vaf->fmt, vaf->va);
),
TP_printk("%s: %s", __get_str(func), __get_str(msg))
);
@ -50,14 +48,12 @@ TRACE_EVENT(brcmf_dbg,
TP_STRUCT__entry(
__field(u32, level)
__string(func, func)
__dynamic_array(char, msg, MAX_MSG_LEN)
__vstring(msg, vaf->fmt, vaf->va)
),
TP_fast_assign(
__entry->level = level;
__assign_str(func, func);
WARN_ON_ONCE(vsnprintf(__get_dynamic_array(msg),
MAX_MSG_LEN, vaf->fmt,
*vaf->va) >= MAX_MSG_LEN);
__assign_vstr(msg, vaf->fmt, vaf->va);
),
TP_printk("%s: %s", __get_str(func), __get_str(msg))
);

View File

@ -28,12 +28,10 @@ DECLARE_EVENT_CLASS(brcms_msg_event,
TP_PROTO(struct va_format *vaf),
TP_ARGS(vaf),
TP_STRUCT__entry(
__dynamic_array(char, msg, MAX_MSG_LEN)
__vstring(msg, vaf->fmt, vaf->va)
),
TP_fast_assign(
WARN_ON_ONCE(vsnprintf(__get_dynamic_array(msg),
MAX_MSG_LEN, vaf->fmt,
*vaf->va) >= MAX_MSG_LEN);
__assign_vstr(msg, vaf->fmt, vaf->va);
),
TP_printk("%s", __get_str(msg))
);
@ -64,14 +62,12 @@ TRACE_EVENT(brcms_dbg,
TP_STRUCT__entry(
__field(u32, level)
__string(func, func)
__dynamic_array(char, msg, MAX_MSG_LEN)
__vstring(msg, vaf->fmt, vaf->va)
),
TP_fast_assign(
__entry->level = level;
__assign_str(func, func);
WARN_ON_ONCE(vsnprintf(__get_dynamic_array(msg),
MAX_MSG_LEN, vaf->fmt,
*vaf->va) >= MAX_MSG_LEN);
__assign_vstr(msg, vaf->fmt, vaf->va);
),
TP_printk("%s: %s", __get_str(func), __get_str(msg))
);

View File

@ -18,12 +18,10 @@ DECLARE_EVENT_CLASS(iwlwifi_msg_event,
TP_PROTO(struct va_format *vaf),
TP_ARGS(vaf),
TP_STRUCT__entry(
__dynamic_array(char, msg, MAX_MSG_LEN)
__vstring(msg, vaf->fmt, vaf->va)
),
TP_fast_assign(
WARN_ON_ONCE(vsnprintf(__get_dynamic_array(msg),
MAX_MSG_LEN, vaf->fmt,
*vaf->va) >= MAX_MSG_LEN);
__assign_vstr(msg, vaf->fmt, vaf->va);
),
TP_printk("%s", __get_str(msg))
);
@ -55,14 +53,12 @@ TRACE_EVENT(iwlwifi_dbg,
TP_STRUCT__entry(
__field(u32, level)
__string(function, function)
__dynamic_array(char, msg, MAX_MSG_LEN)
__vstring(msg, vaf->fmt, vaf->va)
),
TP_fast_assign(
__entry->level = level;
__assign_str(function, function);
WARN_ON_ONCE(vsnprintf(__get_dynamic_array(msg),
MAX_MSG_LEN, vaf->fmt,
*vaf->va) >= MAX_MSG_LEN);
__assign_vstr(msg, vaf->fmt, vaf->va);
),
TP_printk("%s", __get_str(msg))
);

View File

@ -28,11 +28,11 @@ TRACE_EVENT(ci_log,
TP_ARGS(ci, vaf),
TP_STRUCT__entry(
__string(name, dev_name(ci->dev))
__dynamic_array(char, msg, CHIPIDEA_MSG_MAX)
__vstring(msg, vaf->fmt, vaf->va)
),
TP_fast_assign(
__assign_str(name, dev_name(ci->dev));
vsnprintf(__get_str(msg), CHIPIDEA_MSG_MAX, vaf->fmt, *vaf->va);
__assign_vstr(msg, vaf->fmt, vaf->va);
),
TP_printk("%s: %s", __get_str(name), __get_str(msg))
);

View File

@ -28,9 +28,9 @@
DECLARE_EVENT_CLASS(xhci_log_msg,
TP_PROTO(struct va_format *vaf),
TP_ARGS(vaf),
TP_STRUCT__entry(__dynamic_array(char, msg, XHCI_MSG_MAX)),
TP_STRUCT__entry(__vstring(msg, vaf->fmt, vaf->va)),
TP_fast_assign(
vsnprintf(__get_str(msg), XHCI_MSG_MAX, vaf->fmt, *vaf->va);
__assign_vstr(msg, vaf->fmt, vaf->va);
),
TP_printk("%s", __get_str(msg))
);

View File

@ -18,18 +18,16 @@
#include "mtu3.h"
#define MTU3_MSG_MAX 256
TRACE_EVENT(mtu3_log,
TP_PROTO(struct device *dev, struct va_format *vaf),
TP_ARGS(dev, vaf),
TP_STRUCT__entry(
__string(name, dev_name(dev))
__dynamic_array(char, msg, MTU3_MSG_MAX)
__vstring(msg, vaf->fmt, vaf->va)
),
TP_fast_assign(
__assign_str(name, dev_name(dev));
vsnprintf(__get_str(msg), MTU3_MSG_MAX, vaf->fmt, *vaf->va);
__assign_vstr(msg, vaf->fmt, vaf->va);
),
TP_printk("%s: %s", __get_str(name), __get_str(msg))
);

View File

@ -28,11 +28,11 @@ TRACE_EVENT(musb_log,
TP_ARGS(musb, vaf),
TP_STRUCT__entry(
__string(name, dev_name(musb->controller))
__dynamic_array(char, msg, MUSB_MSG_MAX)
__vstring(msg, vaf->fmt, vaf->va)
),
TP_fast_assign(
__assign_str(name, dev_name(musb->controller));
vsnprintf(__get_str(msg), MUSB_MSG_MAX, vaf->fmt, *vaf->va);
__assign_vstr(msg, vaf->fmt, vaf->va);
),
TP_printk("%s: %s", __get_str(name), __get_str(msg))
);

70
include/linux/rv.h Normal file
View File

@ -0,0 +1,70 @@
/* SPDX-License-Identifier: GPL-2.0 */
/*
* Runtime Verification.
*
* For futher information, see: kernel/trace/rv/rv.c.
*/
#ifndef _LINUX_RV_H
#define _LINUX_RV_H
#define MAX_DA_NAME_LEN 24
#ifdef CONFIG_RV
/*
* Deterministic automaton per-object variables.
*/
struct da_monitor {
bool monitoring;
unsigned int curr_state;
};
/*
* Per-task RV monitors count. Nowadays fixed in RV_PER_TASK_MONITORS.
* If we find justification for more monitors, we can think about
* adding more or developing a dynamic method. So far, none of
* these are justified.
*/
#define RV_PER_TASK_MONITORS 1
#define RV_PER_TASK_MONITOR_INIT (RV_PER_TASK_MONITORS)
/*
* Futher monitor types are expected, so make this a union.
*/
union rv_task_monitor {
struct da_monitor da_mon;
};
#ifdef CONFIG_RV_REACTORS
struct rv_reactor {
const char *name;
const char *description;
void (*react)(char *msg);
};
#endif
struct rv_monitor {
const char *name;
const char *description;
bool enabled;
int (*enable)(void);
void (*disable)(void);
void (*reset)(void);
#ifdef CONFIG_RV_REACTORS
void (*react)(char *msg);
#endif
};
bool rv_monitoring_on(void);
int rv_unregister_monitor(struct rv_monitor *monitor);
int rv_register_monitor(struct rv_monitor *monitor);
int rv_get_task_monitor_slot(void);
void rv_put_task_monitor_slot(int slot);
#ifdef CONFIG_RV_REACTORS
bool rv_reacting_on(void);
int rv_unregister_reactor(struct rv_reactor *reactor);
int rv_register_reactor(struct rv_reactor *reactor);
#endif /* CONFIG_RV_REACTORS */
#endif /* CONFIG_RV */
#endif /* _LINUX_RV_H */

View File

@ -34,6 +34,7 @@
#include <linux/rseq.h>
#include <linux/seqlock.h>
#include <linux/kcsan.h>
#include <linux/rv.h>
#include <asm/kmap_size.h>
/* task_struct member predeclarations (sorted alphabetically): */
@ -1501,6 +1502,16 @@ struct task_struct {
struct callback_head l1d_flush_kill;
#endif
#ifdef CONFIG_RV
/*
* Per-task RV monitor. Nowadays fixed in RV_PER_TASK_MONITORS.
* If we find justification for more monitors, we can think
* about adding more or developing a dynamic method. So far,
* none of these are justified.
*/
union rv_task_monitor rv[RV_PER_TASK_MONITORS];
#endif
/*
* New fields for task_struct should be added above here, so that
* they are included in the randomized portion of task_struct.

View File

@ -916,6 +916,24 @@ perf_trace_buf_submit(void *raw_data, int size, int rctx, u16 type,
#endif
#define TRACE_EVENT_STR_MAX 512
/*
* gcc warns that you can not use a va_list in an inlined
* function. But lets me make it into a macro :-/
*/
#define __trace_event_vstr_len(fmt, va) \
({ \
va_list __ap; \
int __ret; \
\
va_copy(__ap, *(va)); \
__ret = vsnprintf(NULL, 0, fmt, __ap) + 1; \
va_end(__ap); \
\
min(__ret, TRACE_EVENT_STR_MAX); \
})
#endif /* _LINUX_TRACE_EVENT_H */
/*

View File

@ -151,7 +151,7 @@ static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p)
/*
* Individual subsystem my have a separate configuration to
* enable their tracepoints. By default, this file will create
* the tracepoints if CONFIG_TRACEPOINT is defined. If a subsystem
* the tracepoints if CONFIG_TRACEPOINTS is defined. If a subsystem
* wants to be able to disable its tracepoints from being created
* it can define NOTRACE before including the tracepoint headers.
*/

75
include/rv/automata.h Normal file
View File

@ -0,0 +1,75 @@
/* SPDX-License-Identifier: GPL-2.0 */
/*
* Copyright (C) 2019-2022 Red Hat, Inc. Daniel Bristot de Oliveira <bristot@kernel.org>
*
* Deterministic automata helper functions, to be used with the automata
* models in C generated by the dot2k tool.
*/
/*
* DECLARE_AUTOMATA_HELPERS - define a set of helper functions for automata
*
* Define a set of helper functions for automata. The 'name' argument is used
* as suffix for the functions and data. These functions will handle automaton
* with data type 'type'.
*/
#define DECLARE_AUTOMATA_HELPERS(name, type) \
\
/* \
* model_get_state_name_##name - return the (string) name of the given state \
*/ \
static char *model_get_state_name_##name(enum states_##name state) \
{ \
if ((state < 0) || (state >= state_max_##name)) \
return "INVALID"; \
\
return automaton_##name.state_names[state]; \
} \
\
/* \
* model_get_event_name_##name - return the (string) name of the given event \
*/ \
static char *model_get_event_name_##name(enum events_##name event) \
{ \
if ((event < 0) || (event >= event_max_##name)) \
return "INVALID"; \
\
return automaton_##name.event_names[event]; \
} \
\
/* \
* model_get_initial_state_##name - return the automaton's initial state \
*/ \
static inline type model_get_initial_state_##name(void) \
{ \
return automaton_##name.initial_state; \
} \
\
/* \
* model_get_next_state_##name - process an automaton event occurrence \
* \
* Given the current state (curr_state) and the event (event), returns \
* the next state, or INVALID_STATE in case of error. \
*/ \
static inline type model_get_next_state_##name(enum states_##name curr_state, \
enum events_##name event) \
{ \
if ((curr_state < 0) || (curr_state >= state_max_##name)) \
return INVALID_STATE; \
\
if ((event < 0) || (event >= event_max_##name)) \
return INVALID_STATE; \
\
return automaton_##name.function[curr_state][event]; \
} \
\
/* \
* model_is_final_state_##name - check if the given state is a final state \
*/ \
static inline bool model_is_final_state_##name(enum states_##name state) \
{ \
if ((state < 0) || (state >= state_max_##name)) \
return 0; \
\
return automaton_##name.final_states[state]; \
}

544
include/rv/da_monitor.h Normal file
View File

@ -0,0 +1,544 @@
/* SPDX-License-Identifier: GPL-2.0 */
/*
* Copyright (C) 2019-2022 Red Hat, Inc. Daniel Bristot de Oliveira <bristot@kernel.org>
*
* Deterministic automata (DA) monitor functions, to be used together
* with automata models in C generated by the dot2k tool.
*
* The dot2k tool is available at tools/verification/dot2k/
*
* For further information, see:
* Documentation/trace/rv/da_monitor_synthesis.rst
*/
#include <rv/automata.h>
#include <linux/rv.h>
#include <linux/bug.h>
#ifdef CONFIG_RV_REACTORS
#define DECLARE_RV_REACTING_HELPERS(name, type) \
static char REACT_MSG_##name[1024]; \
\
static inline char *format_react_msg_##name(type curr_state, type event) \
{ \
snprintf(REACT_MSG_##name, 1024, \
"rv: monitor %s does not allow event %s on state %s\n", \
#name, \
model_get_event_name_##name(event), \
model_get_state_name_##name(curr_state)); \
return REACT_MSG_##name; \
} \
\
static void cond_react_##name(char *msg) \
{ \
if (rv_##name.react) \
rv_##name.react(msg); \
} \
\
static bool rv_reacting_on_##name(void) \
{ \
return rv_reacting_on(); \
}
#else /* CONFIG_RV_REACTOR */
#define DECLARE_RV_REACTING_HELPERS(name, type) \
static inline char *format_react_msg_##name(type curr_state, type event) \
{ \
return NULL; \
} \
\
static void cond_react_##name(char *msg) \
{ \
return; \
} \
\
static bool rv_reacting_on_##name(void) \
{ \
return 0; \
}
#endif
/*
* Generic helpers for all types of deterministic automata monitors.
*/
#define DECLARE_DA_MON_GENERIC_HELPERS(name, type) \
\
DECLARE_RV_REACTING_HELPERS(name, type) \
\
/* \
* da_monitor_reset_##name - reset a monitor and setting it to init state \
*/ \
static inline void da_monitor_reset_##name(struct da_monitor *da_mon) \
{ \
da_mon->monitoring = 0; \
da_mon->curr_state = model_get_initial_state_##name(); \
} \
\
/* \
* da_monitor_curr_state_##name - return the current state \
*/ \
static inline type da_monitor_curr_state_##name(struct da_monitor *da_mon) \
{ \
return da_mon->curr_state; \
} \
\
/* \
* da_monitor_set_state_##name - set the new current state \
*/ \
static inline void \
da_monitor_set_state_##name(struct da_monitor *da_mon, enum states_##name state) \
{ \
da_mon->curr_state = state; \
} \
\
/* \
* da_monitor_start_##name - start monitoring \
* \
* The monitor will ignore all events until monitoring is set to true. This \
* function needs to be called to tell the monitor to start monitoring. \
*/ \
static inline void da_monitor_start_##name(struct da_monitor *da_mon) \
{ \
da_mon->curr_state = model_get_initial_state_##name(); \
da_mon->monitoring = 1; \
} \
\
/* \
* da_monitoring_##name - returns true if the monitor is processing events \
*/ \
static inline bool da_monitoring_##name(struct da_monitor *da_mon) \
{ \
return da_mon->monitoring; \
} \
\
/* \
* da_monitor_enabled_##name - checks if the monitor is enabled \
*/ \
static inline bool da_monitor_enabled_##name(void) \
{ \
/* global switch */ \
if (unlikely(!rv_monitoring_on())) \
return 0; \
\
/* monitor enabled */ \
if (unlikely(!rv_##name.enabled)) \
return 0; \
\
return 1; \
} \
\
/* \
* da_monitor_handling_event_##name - checks if the monitor is ready to handle events \
*/ \
static inline bool da_monitor_handling_event_##name(struct da_monitor *da_mon) \
{ \
\
if (!da_monitor_enabled_##name()) \
return 0; \
\
/* monitor is actually monitoring */ \
if (unlikely(!da_monitoring_##name(da_mon))) \
return 0; \
\
return 1; \
}
/*
* Event handler for implicit monitors. Implicit monitor is the one which the
* handler does not need to specify which da_monitor to manipulate. Examples
* of implicit monitor are the per_cpu or the global ones.
*/
#define DECLARE_DA_MON_MODEL_HANDLER_IMPLICIT(name, type) \
\
static inline bool \
da_event_##name(struct da_monitor *da_mon, enum events_##name event) \
{ \
type curr_state = da_monitor_curr_state_##name(da_mon); \
type next_state = model_get_next_state_##name(curr_state, event); \
\
if (next_state != INVALID_STATE) { \
da_monitor_set_state_##name(da_mon, next_state); \
\
trace_event_##name(model_get_state_name_##name(curr_state), \
model_get_event_name_##name(event), \
model_get_state_name_##name(next_state), \
model_is_final_state_##name(next_state)); \
\
return true; \
} \
\
if (rv_reacting_on_##name()) \
cond_react_##name(format_react_msg_##name(curr_state, event)); \
\
trace_error_##name(model_get_state_name_##name(curr_state), \
model_get_event_name_##name(event)); \
\
return false; \
} \
/*
* Event handler for per_task monitors.
*/
#define DECLARE_DA_MON_MODEL_HANDLER_PER_TASK(name, type) \
\
static inline bool da_event_##name(struct da_monitor *da_mon, struct task_struct *tsk, \
enum events_##name event) \
{ \
type curr_state = da_monitor_curr_state_##name(da_mon); \
type next_state = model_get_next_state_##name(curr_state, event); \
\
if (next_state != INVALID_STATE) { \
da_monitor_set_state_##name(da_mon, next_state); \
\
trace_event_##name(tsk->pid, \
model_get_state_name_##name(curr_state), \
model_get_event_name_##name(event), \
model_get_state_name_##name(next_state), \
model_is_final_state_##name(next_state)); \
\
return true; \
} \
\
if (rv_reacting_on_##name()) \
cond_react_##name(format_react_msg_##name(curr_state, event)); \
\
trace_error_##name(tsk->pid, \
model_get_state_name_##name(curr_state), \
model_get_event_name_##name(event)); \
\
return false; \
}
/*
* Functions to define, init and get a global monitor.
*/
#define DECLARE_DA_MON_INIT_GLOBAL(name, type) \
\
/* \
* global monitor (a single variable) \
*/ \
static struct da_monitor da_mon_##name; \
\
/* \
* da_get_monitor_##name - return the global monitor address \
*/ \
static struct da_monitor *da_get_monitor_##name(void) \
{ \
return &da_mon_##name; \
} \
\
/* \
* da_monitor_reset_all_##name - reset the single monitor \
*/ \
static void da_monitor_reset_all_##name(void) \
{ \
da_monitor_reset_##name(da_get_monitor_##name()); \
} \
\
/* \
* da_monitor_init_##name - initialize a monitor \
*/ \
static inline int da_monitor_init_##name(void) \
{ \
da_monitor_reset_all_##name(); \
return 0; \
} \
\
/* \
* da_monitor_destroy_##name - destroy the monitor \
*/ \
static inline void da_monitor_destroy_##name(void) \
{ \
return; \
}
/*
* Functions to define, init and get a per-cpu monitor.
*/
#define DECLARE_DA_MON_INIT_PER_CPU(name, type) \
\
/* \
* per-cpu monitor variables \
*/ \
DEFINE_PER_CPU(struct da_monitor, da_mon_##name); \
\
/* \
* da_get_monitor_##name - return current CPU monitor address \
*/ \
static struct da_monitor *da_get_monitor_##name(void) \
{ \
return this_cpu_ptr(&da_mon_##name); \
} \
\
/* \
* da_monitor_reset_all_##name - reset all CPUs' monitor \
*/ \
static void da_monitor_reset_all_##name(void) \
{ \
struct da_monitor *da_mon; \
int cpu; \
for_each_cpu(cpu, cpu_online_mask) { \
da_mon = per_cpu_ptr(&da_mon_##name, cpu); \
da_monitor_reset_##name(da_mon); \
} \
} \
\
/* \
* da_monitor_init_##name - initialize all CPUs' monitor \
*/ \
static inline int da_monitor_init_##name(void) \
{ \
da_monitor_reset_all_##name(); \
return 0; \
} \
\
/* \
* da_monitor_destroy_##name - destroy the monitor \
*/ \
static inline void da_monitor_destroy_##name(void) \
{ \
return; \
}
/*
* Functions to define, init and get a per-task monitor.
*/
#define DECLARE_DA_MON_INIT_PER_TASK(name, type) \
\
/* \
* The per-task monitor is stored a vector in the task struct. This variable \
* stores the position on the vector reserved for this monitor. \
*/ \
static int task_mon_slot_##name = RV_PER_TASK_MONITOR_INIT; \
\
/* \
* da_get_monitor_##name - return the monitor in the allocated slot for tsk \
*/ \
static inline struct da_monitor *da_get_monitor_##name(struct task_struct *tsk) \
{ \
return &tsk->rv[task_mon_slot_##name].da_mon; \
} \
\
static void da_monitor_reset_all_##name(void) \
{ \
struct task_struct *g, *p; \
\
read_lock(&tasklist_lock); \
for_each_process_thread(g, p) \
da_monitor_reset_##name(da_get_monitor_##name(p)); \
read_unlock(&tasklist_lock); \
} \
\
/* \
* da_monitor_init_##name - initialize the per-task monitor \
* \
* Try to allocate a slot in the task's vector of monitors. If there \
* is an available slot, use it and reset all task's monitor. \
*/ \
static int da_monitor_init_##name(void) \
{ \
int slot; \
\
slot = rv_get_task_monitor_slot(); \
if (slot < 0 || slot >= RV_PER_TASK_MONITOR_INIT) \
return slot; \
\
task_mon_slot_##name = slot; \
\
da_monitor_reset_all_##name(); \
return 0; \
} \
\
/* \
* da_monitor_destroy_##name - return the allocated slot \
*/ \
static inline void da_monitor_destroy_##name(void) \
{ \
if (task_mon_slot_##name == RV_PER_TASK_MONITOR_INIT) { \
WARN_ONCE(1, "Disabling a disabled monitor: " #name); \
return; \
} \
rv_put_task_monitor_slot(task_mon_slot_##name); \
task_mon_slot_##name = RV_PER_TASK_MONITOR_INIT; \
return; \
}
/*
* Handle event for implicit monitor: da_get_monitor_##name() will figure out
* the monitor.
*/
#define DECLARE_DA_MON_MONITOR_HANDLER_IMPLICIT(name, type) \
\
static inline void __da_handle_event_##name(struct da_monitor *da_mon, \
enum events_##name event) \
{ \
bool retval; \
\
retval = da_event_##name(da_mon, event); \
if (!retval) \
da_monitor_reset_##name(da_mon); \
} \
\
/* \
* da_handle_event_##name - handle an event \
*/ \
static inline void da_handle_event_##name(enum events_##name event) \
{ \
struct da_monitor *da_mon = da_get_monitor_##name(); \
bool retval; \
\
retval = da_monitor_handling_event_##name(da_mon); \
if (!retval) \
return; \
\
__da_handle_event_##name(da_mon, event); \
} \
\
/* \
* da_handle_start_event_##name - start monitoring or handle event \
* \
* This function is used to notify the monitor that the system is returning \
* to the initial state, so the monitor can start monitoring in the next event. \
* Thus: \
* \
* If the monitor already started, handle the event. \
* If the monitor did not start yet, start the monitor but skip the event. \
*/ \
static inline bool da_handle_start_event_##name(enum events_##name event) \
{ \
struct da_monitor *da_mon; \
\
if (!da_monitor_enabled_##name()) \
return 0; \
\
da_mon = da_get_monitor_##name(); \
\
if (unlikely(!da_monitoring_##name(da_mon))) { \
da_monitor_start_##name(da_mon); \
return 0; \
} \
\
__da_handle_event_##name(da_mon, event); \
\
return 1; \
} \
\
/* \
* da_handle_start_run_event_##name - start monitoring and handle event \
* \
* This function is used to notify the monitor that the system is in the \
* initial state, so the monitor can start monitoring and handling event. \
*/ \
static inline bool da_handle_start_run_event_##name(enum events_##name event) \
{ \
struct da_monitor *da_mon; \
\
if (!da_monitor_enabled_##name()) \
return 0; \
\
da_mon = da_get_monitor_##name(); \
\
if (unlikely(!da_monitoring_##name(da_mon))) \
da_monitor_start_##name(da_mon); \
\
__da_handle_event_##name(da_mon, event); \
\
return 1; \
}
/*
* Handle event for per task.
*/
#define DECLARE_DA_MON_MONITOR_HANDLER_PER_TASK(name, type) \
\
static inline void \
__da_handle_event_##name(struct da_monitor *da_mon, struct task_struct *tsk, \
enum events_##name event) \
{ \
bool retval; \
\
retval = da_event_##name(da_mon, tsk, event); \
if (!retval) \
da_monitor_reset_##name(da_mon); \
} \
\
/* \
* da_handle_event_##name - handle an event \
*/ \
static inline void \
da_handle_event_##name(struct task_struct *tsk, enum events_##name event) \
{ \
struct da_monitor *da_mon = da_get_monitor_##name(tsk); \
bool retval; \
\
retval = da_monitor_handling_event_##name(da_mon); \
if (!retval) \
return; \
\
__da_handle_event_##name(da_mon, tsk, event); \
} \
\
/* \
* da_handle_start_event_##name - start monitoring or handle event \
* \
* This function is used to notify the monitor that the system is returning \
* to the initial state, so the monitor can start monitoring in the next event. \
* Thus: \
* \
* If the monitor already started, handle the event. \
* If the monitor did not start yet, start the monitor but skip the event. \
*/ \
static inline bool \
da_handle_start_event_##name(struct task_struct *tsk, enum events_##name event) \
{ \
struct da_monitor *da_mon; \
\
if (!da_monitor_enabled_##name()) \
return 0; \
\
da_mon = da_get_monitor_##name(tsk); \
\
if (unlikely(!da_monitoring_##name(da_mon))) { \
da_monitor_start_##name(da_mon); \
return 0; \
} \
\
__da_handle_event_##name(da_mon, tsk, event); \
\
return 1; \
}
/*
* Entry point for the global monitor.
*/
#define DECLARE_DA_MON_GLOBAL(name, type) \
\
DECLARE_AUTOMATA_HELPERS(name, type) \
DECLARE_DA_MON_GENERIC_HELPERS(name, type) \
DECLARE_DA_MON_MODEL_HANDLER_IMPLICIT(name, type) \
DECLARE_DA_MON_INIT_GLOBAL(name, type) \
DECLARE_DA_MON_MONITOR_HANDLER_IMPLICIT(name, type)
/*
* Entry point for the per-cpu monitor.
*/
#define DECLARE_DA_MON_PER_CPU(name, type) \
\
DECLARE_AUTOMATA_HELPERS(name, type) \
DECLARE_DA_MON_GENERIC_HELPERS(name, type) \
DECLARE_DA_MON_MODEL_HANDLER_IMPLICIT(name, type) \
DECLARE_DA_MON_INIT_PER_CPU(name, type) \
DECLARE_DA_MON_MONITOR_HANDLER_IMPLICIT(name, type)
/*
* Entry point for the per-task monitor.
*/
#define DECLARE_DA_MON_PER_TASK(name, type) \
\
DECLARE_AUTOMATA_HELPERS(name, type) \
DECLARE_DA_MON_GENERIC_HELPERS(name, type) \
DECLARE_DA_MON_MODEL_HANDLER_PER_TASK(name, type) \
DECLARE_DA_MON_INIT_PER_TASK(name, type) \
DECLARE_DA_MON_MONITOR_HANDLER_PER_TASK(name, type)

View File

@ -0,0 +1,29 @@
/* SPDX-License-Identifier: GPL-2.0 */
/*
* Copyright (C) 2019-2022 Red Hat, Inc. Daniel Bristot de Oliveira <bristot@kernel.org>
*
* Helper functions to facilitate the instrumentation of auto-generated
* RV monitors create by dot2k.
*
* The dot2k tool is available at tools/verification/dot2/
*/
#include <linux/ftrace.h>
/*
* rv_attach_trace_probe - check and attach a handler function to a tracepoint
*/
#define rv_attach_trace_probe(monitor, tp, rv_handler) \
do { \
check_trace_callback_type_##tp(rv_handler); \
WARN_ONCE(register_trace_##tp(rv_handler, NULL), \
"fail attaching " #monitor " " #tp "handler"); \
} while (0)
/*
* rv_detach_trace_probe - detach a handler function to a tracepoint
*/
#define rv_detach_trace_probe(monitor, tp, rv_handler) \
do { \
unregister_trace_##tp(rv_handler, NULL); \
} while (0)

View File

@ -186,7 +186,7 @@ TRACE_EVENT(devlink_trap_report,
__string(driver_name, devlink_to_dev(devlink)->driver->name)
__string(trap_name, metadata->trap_name)
__string(trap_group_name, metadata->trap_group_name)
__dynamic_array(char, input_dev_name, IFNAMSIZ)
__array(char, input_dev_name, IFNAMSIZ)
),
TP_fast_assign(
@ -197,15 +197,14 @@ TRACE_EVENT(devlink_trap_report,
__assign_str(driver_name, devlink_to_dev(devlink)->driver->name);
__assign_str(trap_name, metadata->trap_name);
__assign_str(trap_group_name, metadata->trap_group_name);
__assign_str(input_dev_name,
(input_dev ? input_dev->name : "NULL"));
strscpy(__entry->input_dev_name, input_dev ? input_dev->name : "NULL", IFNAMSIZ);
),
TP_printk("bus_name=%s dev_name=%s driver_name=%s trap_name=%s "
"trap_group_name=%s input_dev_name=%s", __get_str(bus_name),
__get_str(dev_name), __get_str(driver_name),
__get_str(trap_name), __get_str(trap_group_name),
__get_str(input_dev_name))
__entry->input_dev_name)
);
#endif /* _TRACE_DEVLINK_H */

View File

@ -32,7 +32,7 @@ TRACE_EVENT(fib_table_lookup,
__array( __u8, gw6, 16 )
__field( u16, sport )
__field( u16, dport )
__dynamic_array(char, name, IFNAMSIZ )
__array(char, name, IFNAMSIZ )
),
TP_fast_assign(
@ -66,7 +66,7 @@ TRACE_EVENT(fib_table_lookup,
}
dev = nhc ? nhc->nhc_dev : NULL;
__assign_str(name, dev ? dev->name : "-");
strlcpy(__entry->name, dev ? dev->name : "-", IFNAMSIZ);
if (nhc) {
if (nhc->nhc_gw_family == AF_INET) {
@ -95,7 +95,7 @@ TRACE_EVENT(fib_table_lookup,
__entry->tb_id, __entry->oif, __entry->iif, __entry->proto,
__entry->src, __entry->sport, __entry->dst, __entry->dport,
__entry->tos, __entry->scope, __entry->flags,
__get_str(name), __entry->gw4, __entry->gw6, __entry->err)
__entry->name, __entry->gw4, __entry->gw6, __entry->err)
);
#endif /* _TRACE_FIB_H */

View File

@ -31,7 +31,7 @@ TRACE_EVENT(fib6_table_lookup,
__field( u16, dport )
__field( u8, proto )
__field( u8, rt_type )
__dynamic_array( char, name, IFNAMSIZ )
__array( char, name, IFNAMSIZ )
__array( __u8, gw, 16 )
),
@ -63,9 +63,9 @@ TRACE_EVENT(fib6_table_lookup,
}
if (res->nh && res->nh->fib_nh_dev) {
__assign_str(name, res->nh->fib_nh_dev);
strlcpy(__entry->name, res->nh->fib_nh_dev->name, IFNAMSIZ);
} else {
__assign_str(name, "-");
strcpy(__entry->name, "-");
}
if (res->f6i == net->ipv6.fib6_null_entry) {
struct in6_addr in6_zero = {};
@ -83,7 +83,7 @@ TRACE_EVENT(fib6_table_lookup,
__entry->tb_id, __entry->oif, __entry->iif, __entry->proto,
__entry->src, __entry->sport, __entry->dst, __entry->dport,
__entry->tos, __entry->scope, __entry->flags,
__get_str(name), __entry->gw, __entry->err)
__entry->name, __entry->gw, __entry->err)
);
#endif /* _TRACE_FIB6_H */

View File

@ -26,12 +26,12 @@ DECLARE_EVENT_CLASS(iscsi_log_msg,
TP_STRUCT__entry(
__string(dname, dev_name(dev) )
__dynamic_array(char, msg, ISCSI_MSG_MAX )
__vstring(msg, vaf->fmt, vaf->va)
),
TP_fast_assign(
__assign_str(dname, dev_name(dev));
vsnprintf(__get_str(msg), ISCSI_MSG_MAX, vaf->fmt, *vaf->va);
__assign_vstr(msg, vaf->fmt, vaf->va);
),
TP_printk("%s: %s",__get_str(dname), __get_str(msg)

View File

@ -30,7 +30,7 @@ TRACE_EVENT(neigh_create,
TP_STRUCT__entry(
__field(u32, family)
__dynamic_array(char, dev, IFNAMSIZ )
__string(dev, dev ? dev->name : "NULL")
__field(int, entries)
__field(u8, created)
__field(u8, gc_exempt)

View File

@ -22,11 +22,11 @@ DECLARE_EVENT_CLASS(qla_log_event,
TP_STRUCT__entry(
__string(buf, buf)
__dynamic_array(char, msg, QLA_MSG_MAX)
__vstring(msg, vaf->fmt, vaf->va)
),
TP_fast_assign(
__assign_str(buf, buf);
vsnprintf(__get_str(msg), QLA_MSG_MAX, vaf->fmt, *vaf->va);
__assign_vstr(msg, vaf->fmt, vaf->va);
),
TP_printk("%s %s", __get_str(buf), __get_str(msg))

142
include/trace/events/rv.h Normal file
View File

@ -0,0 +1,142 @@
/* SPDX-License-Identifier: GPL-2.0 */
#undef TRACE_SYSTEM
#define TRACE_SYSTEM rv
#if !defined(_TRACE_RV_H) || defined(TRACE_HEADER_MULTI_READ)
#define _TRACE_RV_H
#include <linux/rv.h>
#include <linux/tracepoint.h>
#ifdef CONFIG_DA_MON_EVENTS_IMPLICIT
DECLARE_EVENT_CLASS(event_da_monitor,
TP_PROTO(char *state, char *event, char *next_state, bool final_state),
TP_ARGS(state, event, next_state, final_state),
TP_STRUCT__entry(
__array( char, state, MAX_DA_NAME_LEN )
__array( char, event, MAX_DA_NAME_LEN )
__array( char, next_state, MAX_DA_NAME_LEN )
__field( bool, final_state )
),
TP_fast_assign(
memcpy(__entry->state, state, MAX_DA_NAME_LEN);
memcpy(__entry->event, event, MAX_DA_NAME_LEN);
memcpy(__entry->next_state, next_state, MAX_DA_NAME_LEN);
__entry->final_state = final_state;
),
TP_printk("%s x %s -> %s %s",
__entry->state,
__entry->event,
__entry->next_state,
__entry->final_state ? "(final)" : "")
);
DECLARE_EVENT_CLASS(error_da_monitor,
TP_PROTO(char *state, char *event),
TP_ARGS(state, event),
TP_STRUCT__entry(
__array( char, state, MAX_DA_NAME_LEN )
__array( char, event, MAX_DA_NAME_LEN )
),
TP_fast_assign(
memcpy(__entry->state, state, MAX_DA_NAME_LEN);
memcpy(__entry->event, event, MAX_DA_NAME_LEN);
),
TP_printk("event %s not expected in the state %s",
__entry->event,
__entry->state)
);
#ifdef CONFIG_RV_MON_WIP
DEFINE_EVENT(event_da_monitor, event_wip,
TP_PROTO(char *state, char *event, char *next_state, bool final_state),
TP_ARGS(state, event, next_state, final_state));
DEFINE_EVENT(error_da_monitor, error_wip,
TP_PROTO(char *state, char *event),
TP_ARGS(state, event));
#endif /* CONFIG_RV_MON_WIP */
#endif /* CONFIG_DA_MON_EVENTS_IMPLICIT */
#ifdef CONFIG_DA_MON_EVENTS_ID
DECLARE_EVENT_CLASS(event_da_monitor_id,
TP_PROTO(int id, char *state, char *event, char *next_state, bool final_state),
TP_ARGS(id, state, event, next_state, final_state),
TP_STRUCT__entry(
__field( int, id )
__array( char, state, MAX_DA_NAME_LEN )
__array( char, event, MAX_DA_NAME_LEN )
__array( char, next_state, MAX_DA_NAME_LEN )
__field( bool, final_state )
),
TP_fast_assign(
memcpy(__entry->state, state, MAX_DA_NAME_LEN);
memcpy(__entry->event, event, MAX_DA_NAME_LEN);
memcpy(__entry->next_state, next_state, MAX_DA_NAME_LEN);
__entry->id = id;
__entry->final_state = final_state;
),
TP_printk("%d: %s x %s -> %s %s",
__entry->id,
__entry->state,
__entry->event,
__entry->next_state,
__entry->final_state ? "(final)" : "")
);
DECLARE_EVENT_CLASS(error_da_monitor_id,
TP_PROTO(int id, char *state, char *event),
TP_ARGS(id, state, event),
TP_STRUCT__entry(
__field( int, id )
__array( char, state, MAX_DA_NAME_LEN )
__array( char, event, MAX_DA_NAME_LEN )
),
TP_fast_assign(
memcpy(__entry->state, state, MAX_DA_NAME_LEN);
memcpy(__entry->event, event, MAX_DA_NAME_LEN);
__entry->id = id;
),
TP_printk("%d: event %s not expected in the state %s",
__entry->id,
__entry->event,
__entry->state)
);
#ifdef CONFIG_RV_MON_WWNR
/* id is the pid of the task */
DEFINE_EVENT(event_da_monitor_id, event_wwnr,
TP_PROTO(int id, char *state, char *event, char *next_state, bool final_state),
TP_ARGS(id, state, event, next_state, final_state));
DEFINE_EVENT(error_da_monitor_id, error_wwnr,
TP_PROTO(int id, char *state, char *event),
TP_ARGS(id, state, event));
#endif /* CONFIG_RV_MON_WWNR */
#endif /* CONFIG_DA_MON_EVENTS_ID */
#endif /* _TRACE_RV_H */
/* This part ust be outside protection */
#undef TRACE_INCLUDE_PATH
#include <trace/define_trace.h>

View File

@ -26,6 +26,9 @@
#undef __string_len
#define __string_len(item, src, len) __dynamic_array(char, item, -1)
#undef __vstring
#define __vstring(item, fmt, ap) __dynamic_array(char, item, -1)
#undef __bitmask
#define __bitmask(item, nr_bits) __dynamic_array(char, item, -1)

View File

@ -32,6 +32,9 @@
#undef __string_len
#define __string_len(item, src, len) __dynamic_array(char, item, -1)
#undef __vstring
#define __vstring(item, fmt, ap) __dynamic_array(char, item, -1)
#undef __bitmask
#define __bitmask(item, nr_bits) __dynamic_array(unsigned long, item, -1)

View File

@ -2,16 +2,18 @@
/* Stage 4 definitions for creating trace events */
#define ALIGN_STRUCTFIELD(type) ((int)(__alignof__(struct {type b;})))
#undef __field_ext
#define __field_ext(_type, _item, _filter_type) { \
.type = #_type, .name = #_item, \
.size = sizeof(_type), .align = __alignof__(_type), \
.size = sizeof(_type), .align = ALIGN_STRUCTFIELD(_type), \
.is_signed = is_signed_type(_type), .filter_type = _filter_type },
#undef __field_struct_ext
#define __field_struct_ext(_type, _item, _filter_type) { \
.type = #_type, .name = #_item, \
.size = sizeof(_type), .align = __alignof__(_type), \
.size = sizeof(_type), .align = ALIGN_STRUCTFIELD(_type), \
0, .filter_type = _filter_type },
#undef __field
@ -23,7 +25,7 @@
#undef __array
#define __array(_type, _item, _len) { \
.type = #_type"["__stringify(_len)"]", .name = #_item, \
.size = sizeof(_type[_len]), .align = __alignof__(_type), \
.size = sizeof(_type[_len]), .align = ALIGN_STRUCTFIELD(_type), \
.is_signed = is_signed_type(_type), .filter_type = FILTER_OTHER },
#undef __dynamic_array
@ -38,6 +40,9 @@
#undef __string_len
#define __string_len(item, src, len) __dynamic_array(char, item, -1)
#undef __vstring
#define __vstring(item, fmt, ap) __dynamic_array(char, item, -1)
#undef __bitmask
#define __bitmask(item, nr_bits) __dynamic_array(unsigned long, item, -1)

View File

@ -39,6 +39,10 @@
#undef __string_len
#define __string_len(item, src, len) __dynamic_array(char, item, (len) + 1)
#undef __vstring
#define __vstring(item, fmt, ap) __dynamic_array(char, item, \
__trace_event_vstr_len(fmt, ap))
#undef __rel_dynamic_array
#define __rel_dynamic_array(type, item, len) \
__item_length = (len) * sizeof(type); \

View File

@ -24,6 +24,9 @@
#undef __string_len
#define __string_len(item, src, len) __dynamic_array(char, item, -1)
#undef __vstring
#define __vstring(item, fmt, ap) __dynamic_array(char, item, -1)
#undef __assign_str
#define __assign_str(dst, src) \
strcpy(__get_str(dst), (src) ? (const char *)(src) : "(null)");
@ -35,6 +38,15 @@
__get_str(dst)[len] = '\0'; \
} while(0)
#undef __assign_vstr
#define __assign_vstr(dst, fmt, va) \
do { \
va_list __cp_va; \
va_copy(__cp_va, *(va)); \
vsnprintf(__get_str(dst), TRACE_EVENT_STR_MAX, fmt, __cp_va); \
va_end(__cp_va); \
} while (0)
#undef __bitmask
#define __bitmask(item, nr_bits) __dynamic_array(unsigned long, item, -1)

View File

@ -1965,6 +1965,18 @@ static void copy_oom_score_adj(u64 clone_flags, struct task_struct *tsk)
mutex_unlock(&oom_adj_mutex);
}
#ifdef CONFIG_RV
static void rv_task_fork(struct task_struct *p)
{
int i;
for (i = 0; i < RV_PER_TASK_MONITORS; i++)
p->rv[i].da_mon.monitoring = false;
}
#else
#define rv_task_fork(p) do {} while (0)
#endif
/*
* This creates a new process as a copy of the old one,
* but does not actually start it yet.
@ -2403,6 +2415,8 @@ static __latent_entropy struct task_struct *copy_process(
*/
copy_seccomp(p);
rv_task_fork(p);
rseq_fork(p, clone_flags);
/* Don't start children in a dying pid namespace */

View File

@ -1106,4 +1106,6 @@ config HIST_TRIGGERS_DEBUG
If unsure, say N.
source "kernel/trace/rv/Kconfig"
endif # FTRACE

View File

@ -106,5 +106,6 @@ obj-$(CONFIG_FPROBE) += fprobe.o
obj-$(CONFIG_RETHOOK) += rethook.o
obj-$(CONFIG_TRACEPOINT_BENCHMARK) += trace_benchmark.o
obj-$(CONFIG_RV) += rv/
libftrace-y := ftrace.o

78
kernel/trace/rv/Kconfig Normal file
View File

@ -0,0 +1,78 @@
# SPDX-License-Identifier: GPL-2.0-only
#
config DA_MON_EVENTS
bool
config DA_MON_EVENTS_IMPLICIT
select DA_MON_EVENTS
bool
config DA_MON_EVENTS_ID
select DA_MON_EVENTS
bool
menuconfig RV
bool "Runtime Verification"
depends on TRACING
help
Enable the kernel runtime verification infrastructure. RV is a
lightweight (yet rigorous) method that complements classical
exhaustive verification techniques (such as model checking and
theorem proving). RV works by analyzing the trace of the system's
actual execution, comparing it against a formal specification of
the system behavior.
For further information, see:
Documentation/trace/rv/runtime-verification.rst
config RV_MON_WIP
depends on RV
depends on PREEMPT_TRACER
select DA_MON_EVENTS_IMPLICIT
bool "wip monitor"
help
Enable wip (wakeup in preemptive) sample monitor that illustrates
the usage of per-cpu monitors, and one limitation of the
preempt_disable/enable events.
For further information, see:
Documentation/trace/rv/monitor_wip.rst
config RV_MON_WWNR
depends on RV
select DA_MON_EVENTS_ID
bool "wwnr monitor"
help
Enable wwnr (wakeup while not running) sample monitor, this is a
sample monitor that illustrates the usage of per-task monitor.
The model is borken on purpose: it serves to test reactors.
For further information, see:
Documentation/trace/rv/monitor_wwnr.rst
config RV_REACTORS
bool "Runtime verification reactors"
default y
depends on RV
help
Enables the online runtime verification reactors. A runtime
monitor can cause a reaction to the detection of an exception
on the model's execution. By default, the monitors have
tracing reactions, printing the monitor output via tracepoints,
but other reactions can be added (on-demand) via this interface.
config RV_REACT_PRINTK
bool "Printk reactor"
depends on RV_REACTORS
default y
help
Enables the printk reactor. The printk reactor emits a printk()
message if an exception is found.
config RV_REACT_PANIC
bool "Panic reactor"
depends on RV_REACTORS
default y
help
Enables the panic reactor. The panic reactor emits a printk()
message if an exception is found and panic()s the system.

8
kernel/trace/rv/Makefile Normal file
View File

@ -0,0 +1,8 @@
# SPDX-License-Identifier: GPL-2.0
obj-$(CONFIG_RV) += rv.o
obj-$(CONFIG_RV_MON_WIP) += monitors/wip/wip.o
obj-$(CONFIG_RV_MON_WWNR) += monitors/wwnr/wwnr.o
obj-$(CONFIG_RV_REACTORS) += rv_reactors.o
obj-$(CONFIG_RV_REACT_PRINTK) += reactor_printk.o
obj-$(CONFIG_RV_REACT_PANIC) += reactor_panic.o

View File

@ -0,0 +1,88 @@
// SPDX-License-Identifier: GPL-2.0
#include <linux/ftrace.h>
#include <linux/tracepoint.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/rv.h>
#include <rv/instrumentation.h>
#include <rv/da_monitor.h>
#define MODULE_NAME "wip"
#include <trace/events/rv.h>
#include <trace/events/sched.h>
#include <trace/events/preemptirq.h>
#include "wip.h"
struct rv_monitor rv_wip;
DECLARE_DA_MON_PER_CPU(wip, unsigned char);
static void handle_preempt_disable(void *data, unsigned long ip, unsigned long parent_ip)
{
da_handle_event_wip(preempt_disable_wip);
}
static void handle_preempt_enable(void *data, unsigned long ip, unsigned long parent_ip)
{
da_handle_start_event_wip(preempt_enable_wip);
}
static void handle_sched_waking(void *data, struct task_struct *task)
{
da_handle_event_wip(sched_waking_wip);
}
static int enable_wip(void)
{
int retval;
retval = da_monitor_init_wip();
if (retval)
return retval;
rv_attach_trace_probe("wip", preempt_enable, handle_preempt_enable);
rv_attach_trace_probe("wip", sched_waking, handle_sched_waking);
rv_attach_trace_probe("wip", preempt_disable, handle_preempt_disable);
return 0;
}
static void disable_wip(void)
{
rv_wip.enabled = 0;
rv_detach_trace_probe("wip", preempt_disable, handle_preempt_disable);
rv_detach_trace_probe("wip", preempt_enable, handle_preempt_enable);
rv_detach_trace_probe("wip", sched_waking, handle_sched_waking);
da_monitor_destroy_wip();
}
struct rv_monitor rv_wip = {
.name = "wip",
.description = "wakeup in preemptive per-cpu testing monitor.",
.enable = enable_wip,
.disable = disable_wip,
.reset = da_monitor_reset_all_wip,
.enabled = 0,
};
static int register_wip(void)
{
rv_register_monitor(&rv_wip);
return 0;
}
static void unregister_wip(void)
{
rv_unregister_monitor(&rv_wip);
}
module_init(register_wip);
module_exit(unregister_wip);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Daniel Bristot de Oliveira <bristot@kernel.org>");
MODULE_DESCRIPTION("wip: wakeup in preemptive - per-cpu sample monitor.");

View File

@ -0,0 +1,46 @@
/*
* Automatically generated C representation of wip automaton
* For further information about this format, see kernel documentation:
* Documentation/trace/rv/deterministic_automata.rst
*/
enum states_wip {
preemptive_wip = 0,
non_preemptive_wip,
state_max_wip
};
#define INVALID_STATE state_max_wip
enum events_wip {
preempt_disable_wip = 0,
preempt_enable_wip,
sched_waking_wip,
event_max_wip
};
struct automaton_wip {
char *state_names[state_max_wip];
char *event_names[event_max_wip];
unsigned char function[state_max_wip][event_max_wip];
unsigned char initial_state;
bool final_states[state_max_wip];
};
struct automaton_wip automaton_wip = {
.state_names = {
"preemptive",
"non_preemptive"
},
.event_names = {
"preempt_disable",
"preempt_enable",
"sched_waking"
},
.function = {
{ non_preemptive_wip, INVALID_STATE, INVALID_STATE },
{ INVALID_STATE, preemptive_wip, non_preemptive_wip },
},
.initial_state = preemptive_wip,
.final_states = { 1, 0 },
};

View File

@ -0,0 +1,87 @@
// SPDX-License-Identifier: GPL-2.0
#include <linux/ftrace.h>
#include <linux/tracepoint.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/rv.h>
#include <rv/instrumentation.h>
#include <rv/da_monitor.h>
#define MODULE_NAME "wwnr"
#include <trace/events/rv.h>
#include <trace/events/sched.h>
#include "wwnr.h"
struct rv_monitor rv_wwnr;
DECLARE_DA_MON_PER_TASK(wwnr, unsigned char);
static void handle_switch(void *data, bool preempt, struct task_struct *p,
struct task_struct *n, unsigned int prev_state)
{
/* start monitoring only after the first suspension */
if (prev_state == TASK_INTERRUPTIBLE)
da_handle_start_event_wwnr(p, switch_out_wwnr);
else
da_handle_event_wwnr(p, switch_out_wwnr);
da_handle_event_wwnr(n, switch_in_wwnr);
}
static void handle_wakeup(void *data, struct task_struct *p)
{
da_handle_event_wwnr(p, wakeup_wwnr);
}
static int enable_wwnr(void)
{
int retval;
retval = da_monitor_init_wwnr();
if (retval)
return retval;
rv_attach_trace_probe("wwnr", sched_switch, handle_switch);
rv_attach_trace_probe("wwnr", sched_wakeup, handle_wakeup);
return 0;
}
static void disable_wwnr(void)
{
rv_wwnr.enabled = 0;
rv_detach_trace_probe("wwnr", sched_switch, handle_switch);
rv_detach_trace_probe("wwnr", sched_wakeup, handle_wakeup);
da_monitor_destroy_wwnr();
}
struct rv_monitor rv_wwnr = {
.name = "wwnr",
.description = "wakeup while not running per-task testing model.",
.enable = enable_wwnr,
.disable = disable_wwnr,
.reset = da_monitor_reset_all_wwnr,
.enabled = 0,
};
static int register_wwnr(void)
{
rv_register_monitor(&rv_wwnr);
return 0;
}
static void unregister_wwnr(void)
{
rv_unregister_monitor(&rv_wwnr);
}
module_init(register_wwnr);
module_exit(unregister_wwnr);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Daniel Bristot de Oliveira <bristot@kernel.org>");
MODULE_DESCRIPTION("wwnr: wakeup while not running monitor");

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@ -0,0 +1,46 @@
/*
* Automatically generated C representation of wwnr automaton
* For further information about this format, see kernel documentation:
* Documentation/trace/rv/deterministic_automata.rst
*/
enum states_wwnr {
not_running_wwnr = 0,
running_wwnr,
state_max_wwnr
};
#define INVALID_STATE state_max_wwnr
enum events_wwnr {
switch_in_wwnr = 0,
switch_out_wwnr,
wakeup_wwnr,
event_max_wwnr
};
struct automaton_wwnr {
char *state_names[state_max_wwnr];
char *event_names[event_max_wwnr];
unsigned char function[state_max_wwnr][event_max_wwnr];
unsigned char initial_state;
bool final_states[state_max_wwnr];
};
struct automaton_wwnr automaton_wwnr = {
.state_names = {
"not_running",
"running"
},
.event_names = {
"switch_in",
"switch_out",
"wakeup"
},
.function = {
{ running_wwnr, INVALID_STATE, not_running_wwnr },
{ INVALID_STATE, not_running_wwnr, INVALID_STATE },
},
.initial_state = not_running_wwnr,
.final_states = { 1, 0 },
};

View File

@ -0,0 +1,43 @@
// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2019-2022 Red Hat, Inc. Daniel Bristot de Oliveira <bristot@kernel.org>
*
* Panic RV reactor:
* Prints the exception msg to the kernel message log and panic().
*/
#include <linux/ftrace.h>
#include <linux/tracepoint.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/rv.h>
static void rv_panic_reaction(char *msg)
{
panic(msg);
}
static struct rv_reactor rv_panic = {
.name = "panic",
.description = "panic the system if an exception is found.",
.react = rv_panic_reaction
};
static int register_react_panic(void)
{
rv_register_reactor(&rv_panic);
return 0;
}
static void unregister_react_panic(void)
{
rv_unregister_reactor(&rv_panic);
}
module_init(register_react_panic);
module_exit(unregister_react_panic);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Daniel Bristot de Oliveira");
MODULE_DESCRIPTION("panic rv reactor: panic if an exception is found.");

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@ -0,0 +1,42 @@
// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2019-2022 Red Hat, Inc. Daniel Bristot de Oliveira <bristot@kernel.org>
*
* Printk RV reactor:
* Prints the exception msg to the kernel message log.
*/
#include <linux/ftrace.h>
#include <linux/tracepoint.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/rv.h>
static void rv_printk_reaction(char *msg)
{
printk_deferred(msg);
}
static struct rv_reactor rv_printk = {
.name = "printk",
.description = "prints the exception msg to the kernel message log.",
.react = rv_printk_reaction
};
static int register_react_printk(void)
{
rv_register_reactor(&rv_printk);
return 0;
}
static void unregister_react_printk(void)
{
rv_unregister_reactor(&rv_printk);
}
module_init(register_react_printk);
module_exit(unregister_react_printk);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Daniel Bristot de Oliveira");
MODULE_DESCRIPTION("printk rv reactor: printk if an exception is hit.");

799
kernel/trace/rv/rv.c Normal file
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@ -0,0 +1,799 @@
// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2019-2022 Red Hat, Inc. Daniel Bristot de Oliveira <bristot@kernel.org>
*
* This is the online Runtime Verification (RV) interface.
*
* RV is a lightweight (yet rigorous) method that complements classical
* exhaustive verification techniques (such as model checking and
* theorem proving) with a more practical approach to complex systems.
*
* RV works by analyzing the trace of the system's actual execution,
* comparing it against a formal specification of the system behavior.
* RV can give precise information on the runtime behavior of the
* monitored system while enabling the reaction for unexpected
* events, avoiding, for example, the propagation of a failure on
* safety-critical systems.
*
* The development of this interface roots in the development of the
* paper:
*
* De Oliveira, Daniel Bristot; Cucinotta, Tommaso; De Oliveira, Romulo
* Silva. Efficient formal verification for the Linux kernel. In:
* International Conference on Software Engineering and Formal Methods.
* Springer, Cham, 2019. p. 315-332.
*
* And:
*
* De Oliveira, Daniel Bristot, et al. Automata-based formal analysis
* and verification of the real-time Linux kernel. PhD Thesis, 2020.
*
* == Runtime monitor interface ==
*
* A monitor is the central part of the runtime verification of a system.
*
* The monitor stands in between the formal specification of the desired
* (or undesired) behavior, and the trace of the actual system.
*
* In Linux terms, the runtime verification monitors are encapsulated
* inside the "RV monitor" abstraction. A RV monitor includes a reference
* model of the system, a set of instances of the monitor (per-cpu monitor,
* per-task monitor, and so on), and the helper functions that glue the
* monitor to the system via trace. Generally, a monitor includes some form
* of trace output as a reaction for event parsing and exceptions,
* as depicted bellow:
*
* Linux +----- RV Monitor ----------------------------------+ Formal
* Realm | | Realm
* +-------------------+ +----------------+ +-----------------+
* | Linux kernel | | Monitor | | Reference |
* | Tracing | -> | Instance(s) | <- | Model |
* | (instrumentation) | | (verification) | | (specification) |
* +-------------------+ +----------------+ +-----------------+
* | | |
* | V |
* | +----------+ |
* | | Reaction | |
* | +--+--+--+-+ |
* | | | | |
* | | | +-> trace output ? |
* +------------------------|--|----------------------+
* | +----> panic ?
* +-------> <user-specified>
*
* This file implements the interface for loading RV monitors, and
* to control the verification session.
*
* == Registering monitors ==
*
* The struct rv_monitor defines a set of callback functions to control
* a verification session. For instance, when a given monitor is enabled,
* the "enable" callback function is called to hook the instrumentation
* functions to the kernel trace events. The "disable" function is called
* when disabling the verification session.
*
* A RV monitor is registered via:
* int rv_register_monitor(struct rv_monitor *monitor);
* And unregistered via:
* int rv_unregister_monitor(struct rv_monitor *monitor);
*
* == User interface ==
*
* The user interface resembles kernel tracing interface. It presents
* these files:
*
* "available_monitors"
* - List the available monitors, one per line.
*
* For example:
* # cat available_monitors
* wip
* wwnr
*
* "enabled_monitors"
* - Lists the enabled monitors, one per line;
* - Writing to it enables a given monitor;
* - Writing a monitor name with a '!' prefix disables it;
* - Truncating the file disables all enabled monitors.
*
* For example:
* # cat enabled_monitors
* # echo wip > enabled_monitors
* # echo wwnr >> enabled_monitors
* # cat enabled_monitors
* wip
* wwnr
* # echo '!wip' >> enabled_monitors
* # cat enabled_monitors
* wwnr
* # echo > enabled_monitors
* # cat enabled_monitors
* #
*
* Note that more than one monitor can be enabled concurrently.
*
* "monitoring_on"
* - It is an on/off general switcher for monitoring. Note
* that it does not disable enabled monitors or detach events,
* but stops the per-entity monitors from monitoring the events
* received from the instrumentation. It resembles the "tracing_on"
* switcher.
*
* "monitors/"
* Each monitor will have its own directory inside "monitors/". There
* the monitor specific files will be presented.
* The "monitors/" directory resembles the "events" directory on
* tracefs.
*
* For example:
* # cd monitors/wip/
* # ls
* desc enable
* # cat desc
* auto-generated wakeup in preemptive monitor.
* # cat enable
* 0
*
* For further information, see:
* Documentation/trace/rv/runtime-verification.rst
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#ifdef CONFIG_DA_MON_EVENTS
#define CREATE_TRACE_POINTS
#include <trace/events/rv.h>
#endif
#include "rv.h"
DEFINE_MUTEX(rv_interface_lock);
static struct rv_interface rv_root;
struct dentry *get_monitors_root(void)
{
return rv_root.monitors_dir;
}
/*
* Interface for the monitor register.
*/
static LIST_HEAD(rv_monitors_list);
static int task_monitor_count;
static bool task_monitor_slots[RV_PER_TASK_MONITORS];
int rv_get_task_monitor_slot(void)
{
int i;
lockdep_assert_held(&rv_interface_lock);
if (task_monitor_count == RV_PER_TASK_MONITORS)
return -EBUSY;
task_monitor_count++;
for (i = 0; i < RV_PER_TASK_MONITORS; i++) {
if (task_monitor_slots[i] == false) {
task_monitor_slots[i] = true;
return i;
}
}
WARN_ONCE(1, "RV task_monitor_count and slots are out of sync\n");
return -EINVAL;
}
void rv_put_task_monitor_slot(int slot)
{
lockdep_assert_held(&rv_interface_lock);
if (slot < 0 || slot >= RV_PER_TASK_MONITORS) {
WARN_ONCE(1, "RV releasing an invalid slot!: %d\n", slot);
return;
}
WARN_ONCE(!task_monitor_slots[slot], "RV releasing unused task_monitor_slots: %d\n",
slot);
task_monitor_count--;
task_monitor_slots[slot] = false;
}
/*
* This section collects the monitor/ files and folders.
*/
static ssize_t monitor_enable_read_data(struct file *filp, char __user *user_buf, size_t count,
loff_t *ppos)
{
struct rv_monitor_def *mdef = filp->private_data;
const char *buff;
buff = mdef->monitor->enabled ? "1\n" : "0\n";
return simple_read_from_buffer(user_buf, count, ppos, buff, strlen(buff)+1);
}
/*
* __rv_disable_monitor - disabled an enabled monitor
*/
static int __rv_disable_monitor(struct rv_monitor_def *mdef, bool sync)
{
lockdep_assert_held(&rv_interface_lock);
if (mdef->monitor->enabled) {
mdef->monitor->enabled = 0;
mdef->monitor->disable();
/*
* Wait for the execution of all events to finish.
* Otherwise, the data used by the monitor could
* be inconsistent. i.e., if the monitor is re-enabled.
*/
if (sync)
tracepoint_synchronize_unregister();
return 1;
}
return 0;
}
/**
* rv_disable_monitor - disable a given runtime monitor
*
* Returns 0 on success.
*/
int rv_disable_monitor(struct rv_monitor_def *mdef)
{
__rv_disable_monitor(mdef, true);
return 0;
}
/**
* rv_enable_monitor - enable a given runtime monitor
*
* Returns 0 on success, error otherwise.
*/
int rv_enable_monitor(struct rv_monitor_def *mdef)
{
int retval;
lockdep_assert_held(&rv_interface_lock);
if (mdef->monitor->enabled)
return 0;
retval = mdef->monitor->enable();
if (!retval)
mdef->monitor->enabled = 1;
return retval;
}
/*
* interface for enabling/disabling a monitor.
*/
static ssize_t monitor_enable_write_data(struct file *filp, const char __user *user_buf,
size_t count, loff_t *ppos)
{
struct rv_monitor_def *mdef = filp->private_data;
int retval;
bool val;
retval = kstrtobool_from_user(user_buf, count, &val);
if (retval)
return retval;
retval = count;
mutex_lock(&rv_interface_lock);
if (val)
retval = rv_enable_monitor(mdef);
else
retval = rv_disable_monitor(mdef);
mutex_unlock(&rv_interface_lock);
return retval ? : count;
}
static const struct file_operations interface_enable_fops = {
.open = simple_open,
.llseek = no_llseek,
.write = monitor_enable_write_data,
.read = monitor_enable_read_data,
};
/*
* Interface to read monitors description.
*/
static ssize_t monitor_desc_read_data(struct file *filp, char __user *user_buf, size_t count,
loff_t *ppos)
{
struct rv_monitor_def *mdef = filp->private_data;
char buff[256];
memset(buff, 0, sizeof(buff));
snprintf(buff, sizeof(buff), "%s\n", mdef->monitor->description);
return simple_read_from_buffer(user_buf, count, ppos, buff, strlen(buff) + 1);
}
static const struct file_operations interface_desc_fops = {
.open = simple_open,
.llseek = no_llseek,
.read = monitor_desc_read_data,
};
/*
* During the registration of a monitor, this function creates
* the monitor dir, where the specific options of the monitor
* are exposed.
*/
static int create_monitor_dir(struct rv_monitor_def *mdef)
{
struct dentry *root = get_monitors_root();
const char *name = mdef->monitor->name;
struct dentry *tmp;
int retval;
mdef->root_d = rv_create_dir(name, root);
if (!mdef->root_d)
return -ENOMEM;
tmp = rv_create_file("enable", RV_MODE_WRITE, mdef->root_d, mdef, &interface_enable_fops);
if (!tmp) {
retval = -ENOMEM;
goto out_remove_root;
}
tmp = rv_create_file("desc", RV_MODE_READ, mdef->root_d, mdef, &interface_desc_fops);
if (!tmp) {
retval = -ENOMEM;
goto out_remove_root;
}
retval = reactor_populate_monitor(mdef);
if (retval)
goto out_remove_root;
return 0;
out_remove_root:
rv_remove(mdef->root_d);
return retval;
}
/*
* Available/Enable monitor shared seq functions.
*/
static int monitors_show(struct seq_file *m, void *p)
{
struct rv_monitor_def *mon_def = p;
seq_printf(m, "%s\n", mon_def->monitor->name);
return 0;
}
/*
* Used by the seq file operations at the end of a read
* operation.
*/
static void monitors_stop(struct seq_file *m, void *p)
{
mutex_unlock(&rv_interface_lock);
}
/*
* Available monitor seq functions.
*/
static void *available_monitors_start(struct seq_file *m, loff_t *pos)
{
mutex_lock(&rv_interface_lock);
return seq_list_start(&rv_monitors_list, *pos);
}
static void *available_monitors_next(struct seq_file *m, void *p, loff_t *pos)
{
return seq_list_next(p, &rv_monitors_list, pos);
}
/*
* Enable monitor seq functions.
*/
static void *enabled_monitors_next(struct seq_file *m, void *p, loff_t *pos)
{
struct rv_monitor_def *m_def = p;
(*pos)++;
list_for_each_entry_continue(m_def, &rv_monitors_list, list) {
if (m_def->monitor->enabled)
return m_def;
}
return NULL;
}
static void *enabled_monitors_start(struct seq_file *m, loff_t *pos)
{
struct rv_monitor_def *m_def;
loff_t l;
mutex_lock(&rv_interface_lock);
if (list_empty(&rv_monitors_list))
return NULL;
m_def = list_entry(&rv_monitors_list, struct rv_monitor_def, list);
for (l = 0; l <= *pos; ) {
m_def = enabled_monitors_next(m, m_def, &l);
if (!m_def)
break;
}
return m_def;
}
/*
* available/enabled monitors seq definition.
*/
static const struct seq_operations available_monitors_seq_ops = {
.start = available_monitors_start,
.next = available_monitors_next,
.stop = monitors_stop,
.show = monitors_show
};
static const struct seq_operations enabled_monitors_seq_ops = {
.start = enabled_monitors_start,
.next = enabled_monitors_next,
.stop = monitors_stop,
.show = monitors_show
};
/*
* available_monitors interface.
*/
static int available_monitors_open(struct inode *inode, struct file *file)
{
return seq_open(file, &available_monitors_seq_ops);
};
static const struct file_operations available_monitors_ops = {
.open = available_monitors_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release
};
/*
* enabled_monitors interface.
*/
static void disable_all_monitors(void)
{
struct rv_monitor_def *mdef;
int enabled = 0;
mutex_lock(&rv_interface_lock);
list_for_each_entry(mdef, &rv_monitors_list, list)
enabled += __rv_disable_monitor(mdef, false);
if (enabled) {
/*
* Wait for the execution of all events to finish.
* Otherwise, the data used by the monitor could
* be inconsistent. i.e., if the monitor is re-enabled.
*/
tracepoint_synchronize_unregister();
}
mutex_unlock(&rv_interface_lock);
}
static int enabled_monitors_open(struct inode *inode, struct file *file)
{
if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC))
disable_all_monitors();
return seq_open(file, &enabled_monitors_seq_ops);
};
static ssize_t enabled_monitors_write(struct file *filp, const char __user *user_buf,
size_t count, loff_t *ppos)
{
char buff[MAX_RV_MONITOR_NAME_SIZE + 2];
struct rv_monitor_def *mdef;
int retval = -EINVAL;
bool enable = true;
char *ptr = buff;
int len;
if (count < 1 || count > MAX_RV_MONITOR_NAME_SIZE + 1)
return -EINVAL;
memset(buff, 0, sizeof(buff));
retval = simple_write_to_buffer(buff, sizeof(buff) - 1, ppos, user_buf, count);
if (retval < 0)
return -EFAULT;
ptr = strim(buff);
if (ptr[0] == '!') {
enable = false;
ptr++;
}
len = strlen(ptr);
if (!len)
return count;
mutex_lock(&rv_interface_lock);
retval = -EINVAL;
list_for_each_entry(mdef, &rv_monitors_list, list) {
if (strcmp(ptr, mdef->monitor->name) != 0)
continue;
/*
* Monitor found!
*/
if (enable)
retval = rv_enable_monitor(mdef);
else
retval = rv_disable_monitor(mdef);
if (!retval)
retval = count;
break;
}
mutex_unlock(&rv_interface_lock);
return retval;
}
static const struct file_operations enabled_monitors_ops = {
.open = enabled_monitors_open,
.read = seq_read,
.write = enabled_monitors_write,
.llseek = seq_lseek,
.release = seq_release,
};
/*
* Monitoring on global switcher!
*/
static bool __read_mostly monitoring_on;
/**
* rv_monitoring_on - checks if monitoring is on
*
* Returns 1 if on, 0 otherwise.
*/
bool rv_monitoring_on(void)
{
/* Ensures that concurrent monitors read consistent monitoring_on */
smp_rmb();
return READ_ONCE(monitoring_on);
}
/*
* monitoring_on general switcher.
*/
static ssize_t monitoring_on_read_data(struct file *filp, char __user *user_buf,
size_t count, loff_t *ppos)
{
const char *buff;
buff = rv_monitoring_on() ? "1\n" : "0\n";
return simple_read_from_buffer(user_buf, count, ppos, buff, strlen(buff) + 1);
}
static void turn_monitoring_off(void)
{
WRITE_ONCE(monitoring_on, false);
/* Ensures that concurrent monitors read consistent monitoring_on */
smp_wmb();
}
static void reset_all_monitors(void)
{
struct rv_monitor_def *mdef;
list_for_each_entry(mdef, &rv_monitors_list, list) {
if (mdef->monitor->enabled)
mdef->monitor->reset();
}
}
static void turn_monitoring_on(void)
{
WRITE_ONCE(monitoring_on, true);
/* Ensures that concurrent monitors read consistent monitoring_on */
smp_wmb();
}
static void turn_monitoring_on_with_reset(void)
{
lockdep_assert_held(&rv_interface_lock);
if (rv_monitoring_on())
return;
/*
* Monitors might be out of sync with the system if events were not
* processed because of !rv_monitoring_on().
*
* Reset all monitors, forcing a re-sync.
*/
reset_all_monitors();
turn_monitoring_on();
}
static ssize_t monitoring_on_write_data(struct file *filp, const char __user *user_buf,
size_t count, loff_t *ppos)
{
int retval;
bool val;
retval = kstrtobool_from_user(user_buf, count, &val);
if (retval)
return retval;
mutex_lock(&rv_interface_lock);
if (val)
turn_monitoring_on_with_reset();
else
turn_monitoring_off();
/*
* Wait for the execution of all events to finish
* before returning to user-space.
*/
tracepoint_synchronize_unregister();
mutex_unlock(&rv_interface_lock);
return count;
}
static const struct file_operations monitoring_on_fops = {
.open = simple_open,
.llseek = no_llseek,
.write = monitoring_on_write_data,
.read = monitoring_on_read_data,
};
static void destroy_monitor_dir(struct rv_monitor_def *mdef)
{
reactor_cleanup_monitor(mdef);
rv_remove(mdef->root_d);
}
/**
* rv_register_monitor - register a rv monitor.
* @monitor: The rv_monitor to be registered.
*
* Returns 0 if successful, error otherwise.
*/
int rv_register_monitor(struct rv_monitor *monitor)
{
struct rv_monitor_def *r;
int retval = 0;
if (strlen(monitor->name) >= MAX_RV_MONITOR_NAME_SIZE) {
pr_info("Monitor %s has a name longer than %d\n", monitor->name,
MAX_RV_MONITOR_NAME_SIZE);
return -1;
}
mutex_lock(&rv_interface_lock);
list_for_each_entry(r, &rv_monitors_list, list) {
if (strcmp(monitor->name, r->monitor->name) == 0) {
pr_info("Monitor %s is already registered\n", monitor->name);
retval = -1;
goto out_unlock;
}
}
r = kzalloc(sizeof(struct rv_monitor_def), GFP_KERNEL);
if (!r) {
retval = -ENOMEM;
goto out_unlock;
}
r->monitor = monitor;
retval = create_monitor_dir(r);
if (retval) {
kfree(r);
goto out_unlock;
}
list_add_tail(&r->list, &rv_monitors_list);
out_unlock:
mutex_unlock(&rv_interface_lock);
return retval;
}
/**
* rv_unregister_monitor - unregister a rv monitor.
* @monitor: The rv_monitor to be unregistered.
*
* Returns 0 if successful, error otherwise.
*/
int rv_unregister_monitor(struct rv_monitor *monitor)
{
struct rv_monitor_def *ptr, *next;
mutex_lock(&rv_interface_lock);
list_for_each_entry_safe(ptr, next, &rv_monitors_list, list) {
if (strcmp(monitor->name, ptr->monitor->name) == 0) {
rv_disable_monitor(ptr);
list_del(&ptr->list);
destroy_monitor_dir(ptr);
}
}
mutex_unlock(&rv_interface_lock);
return 0;
}
int __init rv_init_interface(void)
{
struct dentry *tmp;
int retval;
rv_root.root_dir = rv_create_dir("rv", NULL);
if (!rv_root.root_dir)
goto out_err;
rv_root.monitors_dir = rv_create_dir("monitors", rv_root.root_dir);
if (!rv_root.monitors_dir)
goto out_err;
tmp = rv_create_file("available_monitors", RV_MODE_READ, rv_root.root_dir, NULL,
&available_monitors_ops);
if (!tmp)
goto out_err;
tmp = rv_create_file("enabled_monitors", RV_MODE_WRITE, rv_root.root_dir, NULL,
&enabled_monitors_ops);
if (!tmp)
goto out_err;
tmp = rv_create_file("monitoring_on", RV_MODE_WRITE, rv_root.root_dir, NULL,
&monitoring_on_fops);
if (!tmp)
goto out_err;
retval = init_rv_reactors(rv_root.root_dir);
if (retval)
goto out_err;
turn_monitoring_on();
return 0;
out_err:
rv_remove(rv_root.root_dir);
printk(KERN_ERR "RV: Error while creating the RV interface\n");
return 1;
}

68
kernel/trace/rv/rv.h Normal file
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@ -0,0 +1,68 @@
/* SPDX-License-Identifier: GPL-2.0 */
#include <linux/mutex.h>
struct rv_interface {
struct dentry *root_dir;
struct dentry *monitors_dir;
};
#include "../trace.h"
#include <linux/tracefs.h>
#include <linux/rv.h>
#define RV_MODE_WRITE TRACE_MODE_WRITE
#define RV_MODE_READ TRACE_MODE_READ
#define rv_create_dir tracefs_create_dir
#define rv_create_file tracefs_create_file
#define rv_remove tracefs_remove
#define MAX_RV_MONITOR_NAME_SIZE 32
#define MAX_RV_REACTOR_NAME_SIZE 32
extern struct mutex rv_interface_lock;
#ifdef CONFIG_RV_REACTORS
struct rv_reactor_def {
struct list_head list;
struct rv_reactor *reactor;
/* protected by the monitor interface lock */
int counter;
};
#endif
struct rv_monitor_def {
struct list_head list;
struct rv_monitor *monitor;
struct dentry *root_d;
#ifdef CONFIG_RV_REACTORS
struct rv_reactor_def *rdef;
bool reacting;
#endif
bool task_monitor;
};
struct dentry *get_monitors_root(void);
int rv_disable_monitor(struct rv_monitor_def *mdef);
int rv_enable_monitor(struct rv_monitor_def *mdef);
#ifdef CONFIG_RV_REACTORS
int reactor_populate_monitor(struct rv_monitor_def *mdef);
void reactor_cleanup_monitor(struct rv_monitor_def *mdef);
int init_rv_reactors(struct dentry *root_dir);
#else
static inline int reactor_populate_monitor(struct rv_monitor_def *mdef)
{
return 0;
}
static inline void reactor_cleanup_monitor(struct rv_monitor_def *mdef)
{
return;
}
static inline int init_rv_reactors(struct dentry *root_dir)
{
return 0;
}
#endif

View File

@ -0,0 +1,510 @@
// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2019-2022 Red Hat, Inc. Daniel Bristot de Oliveira <bristot@kernel.org>
*
* Runtime reactor interface.
*
* A runtime monitor can cause a reaction to the detection of an
* exception on the model's execution. By default, the monitors have
* tracing reactions, printing the monitor output via tracepoints.
* But other reactions can be added (on-demand) via this interface.
*
* == Registering reactors ==
*
* The struct rv_reactor defines a callback function to be executed
* in case of a model exception happens. The callback function
* receives a message to be (optionally) printed before executing
* the reaction.
*
* A RV reactor is registered via:
* int rv_register_reactor(struct rv_reactor *reactor)
* And unregistered via:
* int rv_unregister_reactor(struct rv_reactor *reactor)
*
* These functions are exported to modules, enabling reactors to be
* dynamically loaded.
*
* == User interface ==
*
* The user interface resembles the kernel tracing interface and
* presents these files:
*
* "available_reactors"
* - List the available reactors, one per line.
*
* For example:
* # cat available_reactors
* nop
* panic
* printk
*
* "reacting_on"
* - It is an on/off general switch for reactors, disabling
* all reactions.
*
* "monitors/MONITOR/reactors"
* - List available reactors, with the select reaction for the given
* MONITOR inside []. The default one is the nop (no operation)
* reactor.
* - Writing the name of an reactor enables it to the given
* MONITOR.
*
* For example:
* # cat monitors/wip/reactors
* [nop]
* panic
* printk
* # echo panic > monitors/wip/reactors
* # cat monitors/wip/reactors
* nop
* [panic]
* printk
*/
#include <linux/slab.h>
#include "rv.h"
/*
* Interface for the reactor register.
*/
static LIST_HEAD(rv_reactors_list);
static struct rv_reactor_def *get_reactor_rdef_by_name(char *name)
{
struct rv_reactor_def *r;
list_for_each_entry(r, &rv_reactors_list, list) {
if (strcmp(name, r->reactor->name) == 0)
return r;
}
return NULL;
}
/*
* Available reactors seq functions.
*/
static int reactors_show(struct seq_file *m, void *p)
{
struct rv_reactor_def *rea_def = p;
seq_printf(m, "%s\n", rea_def->reactor->name);
return 0;
}
static void reactors_stop(struct seq_file *m, void *p)
{
mutex_unlock(&rv_interface_lock);
}
static void *reactors_start(struct seq_file *m, loff_t *pos)
{
mutex_lock(&rv_interface_lock);
return seq_list_start(&rv_reactors_list, *pos);
}
static void *reactors_next(struct seq_file *m, void *p, loff_t *pos)
{
return seq_list_next(p, &rv_reactors_list, pos);
}
/*
* available_reactors seq definition.
*/
static const struct seq_operations available_reactors_seq_ops = {
.start = reactors_start,
.next = reactors_next,
.stop = reactors_stop,
.show = reactors_show
};
/*
* available_reactors interface.
*/
static int available_reactors_open(struct inode *inode, struct file *file)
{
return seq_open(file, &available_reactors_seq_ops);
};
static const struct file_operations available_reactors_ops = {
.open = available_reactors_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release
};
/*
* Monitor's reactor file.
*/
static int monitor_reactor_show(struct seq_file *m, void *p)
{
struct rv_monitor_def *mdef = m->private;
struct rv_reactor_def *rdef = p;
if (mdef->rdef == rdef)
seq_printf(m, "[%s]\n", rdef->reactor->name);
else
seq_printf(m, "%s\n", rdef->reactor->name);
return 0;
}
/*
* available_reactors seq definition.
*/
static const struct seq_operations monitor_reactors_seq_ops = {
.start = reactors_start,
.next = reactors_next,
.stop = reactors_stop,
.show = monitor_reactor_show
};
static void monitor_swap_reactors(struct rv_monitor_def *mdef, struct rv_reactor_def *rdef,
bool reacting)
{
bool monitor_enabled;
/* nothing to do */
if (mdef->rdef == rdef)
return;
monitor_enabled = mdef->monitor->enabled;
if (monitor_enabled)
rv_disable_monitor(mdef);
/* swap reactor's usage */
mdef->rdef->counter--;
rdef->counter++;
mdef->rdef = rdef;
mdef->reacting = reacting;
mdef->monitor->react = rdef->reactor->react;
if (monitor_enabled)
rv_enable_monitor(mdef);
}
static ssize_t
monitor_reactors_write(struct file *file, const char __user *user_buf,
size_t count, loff_t *ppos)
{
char buff[MAX_RV_REACTOR_NAME_SIZE + 2];
struct rv_monitor_def *mdef;
struct rv_reactor_def *rdef;
struct seq_file *seq_f;
int retval = -EINVAL;
bool enable;
char *ptr;
int len;
if (count < 1 || count > MAX_RV_REACTOR_NAME_SIZE + 1)
return -EINVAL;
memset(buff, 0, sizeof(buff));
retval = simple_write_to_buffer(buff, sizeof(buff) - 1, ppos, user_buf, count);
if (retval < 0)
return -EFAULT;
ptr = strim(buff);
len = strlen(ptr);
if (!len)
return count;
/*
* See monitor_reactors_open()
*/
seq_f = file->private_data;
mdef = seq_f->private;
mutex_lock(&rv_interface_lock);
retval = -EINVAL;
list_for_each_entry(rdef, &rv_reactors_list, list) {
if (strcmp(ptr, rdef->reactor->name) != 0)
continue;
if (rdef == get_reactor_rdef_by_name("nop"))
enable = false;
else
enable = true;
monitor_swap_reactors(mdef, rdef, enable);
retval = count;
break;
}
mutex_unlock(&rv_interface_lock);
return retval;
}
/*
* available_reactors interface.
*/
static int monitor_reactors_open(struct inode *inode, struct file *file)
{
struct rv_monitor_def *mdef = inode->i_private;
struct seq_file *seq_f;
int ret;
ret = seq_open(file, &monitor_reactors_seq_ops);
if (ret < 0)
return ret;
/*
* seq_open stores the seq_file on the file->private data.
*/
seq_f = file->private_data;
/*
* Copy the create file "private" data to the seq_file private data.
*/
seq_f->private = mdef;
return 0;
};
static const struct file_operations monitor_reactors_ops = {
.open = monitor_reactors_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release,
.write = monitor_reactors_write
};
static int __rv_register_reactor(struct rv_reactor *reactor)
{
struct rv_reactor_def *r;
list_for_each_entry(r, &rv_reactors_list, list) {
if (strcmp(reactor->name, r->reactor->name) == 0) {
pr_info("Reactor %s is already registered\n", reactor->name);
return -EINVAL;
}
}
r = kzalloc(sizeof(struct rv_reactor_def), GFP_KERNEL);
if (!r)
return -ENOMEM;
r->reactor = reactor;
r->counter = 0;
list_add_tail(&r->list, &rv_reactors_list);
return 0;
}
/**
* rv_register_reactor - register a rv reactor.
* @reactor: The rv_reactor to be registered.
*
* Returns 0 if successful, error otherwise.
*/
int rv_register_reactor(struct rv_reactor *reactor)
{
int retval = 0;
if (strlen(reactor->name) >= MAX_RV_REACTOR_NAME_SIZE) {
pr_info("Reactor %s has a name longer than %d\n",
reactor->name, MAX_RV_MONITOR_NAME_SIZE);
return -EINVAL;
}
mutex_lock(&rv_interface_lock);
retval = __rv_register_reactor(reactor);
mutex_unlock(&rv_interface_lock);
return retval;
}
/**
* rv_unregister_reactor - unregister a rv reactor.
* @reactor: The rv_reactor to be unregistered.
*
* Returns 0 if successful, error otherwise.
*/
int rv_unregister_reactor(struct rv_reactor *reactor)
{
struct rv_reactor_def *ptr, *next;
int ret = 0;
mutex_lock(&rv_interface_lock);
list_for_each_entry_safe(ptr, next, &rv_reactors_list, list) {
if (strcmp(reactor->name, ptr->reactor->name) == 0) {
if (!ptr->counter) {
list_del(&ptr->list);
} else {
printk(KERN_WARNING
"rv: the rv_reactor %s is in use by %d monitor(s)\n",
ptr->reactor->name, ptr->counter);
printk(KERN_WARNING "rv: the rv_reactor %s cannot be removed\n",
ptr->reactor->name);
ret = -EBUSY;
break;
}
}
}
mutex_unlock(&rv_interface_lock);
return ret;
}
/*
* reacting_on interface.
*/
static bool __read_mostly reacting_on;
/**
* rv_reacting_on - checks if reacting is on
*
* Returns 1 if on, 0 otherwise.
*/
bool rv_reacting_on(void)
{
/* Ensures that concurrent monitors read consistent reacting_on */
smp_rmb();
return READ_ONCE(reacting_on);
}
static ssize_t reacting_on_read_data(struct file *filp,
char __user *user_buf,
size_t count, loff_t *ppos)
{
char *buff;
buff = rv_reacting_on() ? "1\n" : "0\n";
return simple_read_from_buffer(user_buf, count, ppos, buff, strlen(buff)+1);
}
static void turn_reacting_off(void)
{
WRITE_ONCE(reacting_on, false);
/* Ensures that concurrent monitors read consistent reacting_on */
smp_wmb();
}
static void turn_reacting_on(void)
{
WRITE_ONCE(reacting_on, true);
/* Ensures that concurrent monitors read consistent reacting_on */
smp_wmb();
}
static ssize_t reacting_on_write_data(struct file *filp, const char __user *user_buf,
size_t count, loff_t *ppos)
{
int retval;
bool val;
retval = kstrtobool_from_user(user_buf, count, &val);
if (retval)
return retval;
mutex_lock(&rv_interface_lock);
if (val)
turn_reacting_on();
else
turn_reacting_off();
/*
* Wait for the execution of all events to finish
* before returning to user-space.
*/
tracepoint_synchronize_unregister();
mutex_unlock(&rv_interface_lock);
return count;
}
static const struct file_operations reacting_on_fops = {
.open = simple_open,
.llseek = no_llseek,
.write = reacting_on_write_data,
.read = reacting_on_read_data,
};
/**
* reactor_populate_monitor - creates per monitor reactors file
* @mdef: monitor's definition.
*
* Returns 0 if successful, error otherwise.
*/
int reactor_populate_monitor(struct rv_monitor_def *mdef)
{
struct dentry *tmp;
tmp = rv_create_file("reactors", RV_MODE_WRITE, mdef->root_d, mdef, &monitor_reactors_ops);
if (!tmp)
return -ENOMEM;
/*
* Configure as the rv_nop reactor.
*/
mdef->rdef = get_reactor_rdef_by_name("nop");
mdef->rdef->counter++;
mdef->reacting = false;
return 0;
}
/**
* reactor_cleanup_monitor - cleanup a monitor reference
* @mdef: monitor's definition.
*/
void reactor_cleanup_monitor(struct rv_monitor_def *mdef)
{
lockdep_assert_held(&rv_interface_lock);
mdef->rdef->counter--;
WARN_ON_ONCE(mdef->rdef->counter < 0);
}
/*
* Nop reactor register
*/
static void rv_nop_reaction(char *msg)
{
}
static struct rv_reactor rv_nop = {
.name = "nop",
.description = "no-operation reactor: do nothing.",
.react = rv_nop_reaction
};
int init_rv_reactors(struct dentry *root_dir)
{
struct dentry *available, *reacting;
int retval;
available = rv_create_file("available_reactors", RV_MODE_READ, root_dir, NULL,
&available_reactors_ops);
if (!available)
goto out_err;
reacting = rv_create_file("reacting_on", RV_MODE_WRITE, root_dir, NULL, &reacting_on_fops);
if (!reacting)
goto rm_available;
retval = __rv_register_reactor(&rv_nop);
if (retval)
goto rm_reacting;
turn_reacting_on();
return 0;
rm_reacting:
rv_remove(reacting);
rm_available:
rv_remove(available);
out_err:
return -ENOMEM;
}

View File

@ -5569,13 +5569,13 @@ static const char readme_msg[] =
#endif
#if defined(CONFIG_KPROBE_EVENTS) || defined(CONFIG_UPROBE_EVENTS)
"\t accepts: event-definitions (one definition per line)\n"
"\t Format: p[:[<group>/]<event>] <place> [<args>]\n"
"\t r[maxactive][:[<group>/]<event>] <place> [<args>]\n"
"\t Format: p[:[<group>/][<event>]] <place> [<args>]\n"
"\t r[maxactive][:[<group>/][<event>]] <place> [<args>]\n"
#ifdef CONFIG_HIST_TRIGGERS
"\t s:[synthetic/]<event> <field> [<field>]\n"
#endif
"\t e[:[<group>/]<event>] <attached-group>.<attached-event> [<args>]\n"
"\t -:[<group>/]<event>\n"
"\t e[:[<group>/][<event>]] <attached-group>.<attached-event> [<args>]\n"
"\t -:[<group>/][<event>]\n"
#ifdef CONFIG_KPROBE_EVENTS
"\t place: [<module>:]<symbol>[+<offset>]|<memaddr>\n"
"place (kretprobe): [<module>:]<symbol>[+<offset>]%return|<memaddr>\n"
@ -9101,6 +9101,16 @@ allocate_trace_buffer(struct trace_array *tr, struct array_buffer *buf, int size
return 0;
}
static void free_trace_buffer(struct array_buffer *buf)
{
if (buf->buffer) {
ring_buffer_free(buf->buffer);
buf->buffer = NULL;
free_percpu(buf->data);
buf->data = NULL;
}
}
static int allocate_trace_buffers(struct trace_array *tr, int size)
{
int ret;
@ -9113,10 +9123,7 @@ static int allocate_trace_buffers(struct trace_array *tr, int size)
ret = allocate_trace_buffer(tr, &tr->max_buffer,
allocate_snapshot ? size : 1);
if (MEM_FAIL(ret, "Failed to allocate trace buffer\n")) {
ring_buffer_free(tr->array_buffer.buffer);
tr->array_buffer.buffer = NULL;
free_percpu(tr->array_buffer.data);
tr->array_buffer.data = NULL;
free_trace_buffer(&tr->array_buffer);
return -ENOMEM;
}
tr->allocated_snapshot = allocate_snapshot;
@ -9131,16 +9138,6 @@ static int allocate_trace_buffers(struct trace_array *tr, int size)
return 0;
}
static void free_trace_buffer(struct array_buffer *buf)
{
if (buf->buffer) {
ring_buffer_free(buf->buffer);
buf->buffer = NULL;
free_percpu(buf->data);
buf->data = NULL;
}
}
static void free_trace_buffers(struct trace_array *tr)
{
if (!tr)
@ -9772,6 +9769,8 @@ static __init int tracer_init_tracefs(void)
tracer_init_tracefs_work_func(NULL);
}
rv_init_interface();
return 0;
}

View File

@ -2005,4 +2005,13 @@ struct trace_min_max_param {
extern const struct file_operations trace_min_max_fops;
#ifdef CONFIG_RV
extern int rv_init_interface(void);
#else
static inline int rv_init_interface(void)
{
return 0;
}
#endif
#endif /* _LINUX_KERNEL_TRACE_H */

View File

@ -101,7 +101,7 @@ int dyn_event_release(const char *raw_command, struct dyn_event_operations *type
event = p + 1;
*p = '\0';
}
if (event[0] == '\0') {
if (!system && event[0] == '\0') {
ret = -EINVAL;
goto out;
}

View File

@ -125,6 +125,7 @@ static bool eprobe_dyn_event_match(const char *system, const char *event,
* We match the following:
* event only - match all eprobes with event name
* system and event only - match all system/event probes
* system only - match all system probes
*
* The below has the above satisfied with more arguments:
*
@ -143,7 +144,7 @@ static bool eprobe_dyn_event_match(const char *system, const char *event,
return false;
/* Must match the event name */
if (strcmp(trace_probe_name(&ep->tp), event) != 0)
if (event[0] != '\0' && strcmp(trace_probe_name(&ep->tp), event) != 0)
return false;
/* No arguments match all */
@ -838,8 +839,11 @@ static int trace_eprobe_tp_update_arg(struct trace_eprobe *ep, const char *argv[
if (ret)
return ret;
if (ep->tp.args[i].code->op == FETCH_OP_TP_ARG)
if (ep->tp.args[i].code->op == FETCH_OP_TP_ARG) {
ret = trace_eprobe_tp_arg_update(ep, i);
if (ret)
trace_probe_log_err(0, BAD_ATTACH_ARG);
}
return ret;
}
@ -848,7 +852,7 @@ static int __trace_eprobe_create(int argc, const char *argv[])
{
/*
* Argument syntax:
* e[:[GRP/]ENAME] SYSTEM.EVENT [FETCHARGS]
* e[:[GRP/][ENAME]] SYSTEM.EVENT [FETCHARGS]
* Fetch args:
* <name>=$<field>[:TYPE]
*/
@ -858,6 +862,7 @@ static int __trace_eprobe_create(int argc, const char *argv[])
struct trace_eprobe *ep = NULL;
char buf1[MAX_EVENT_NAME_LEN];
char buf2[MAX_EVENT_NAME_LEN];
char gbuf[MAX_EVENT_NAME_LEN];
int ret = 0;
int i;
@ -869,25 +874,25 @@ static int __trace_eprobe_create(int argc, const char *argv[])
event = strchr(&argv[0][1], ':');
if (event) {
event++;
ret = traceprobe_parse_event_name(&event, &group, buf1,
ret = traceprobe_parse_event_name(&event, &group, gbuf,
event - argv[0]);
if (ret)
goto parse_error;
} else {
}
trace_probe_log_set_index(1);
sys_event = argv[1];
ret = traceprobe_parse_event_name(&sys_event, &sys_name, buf2, 0);
if (!sys_event || !sys_name) {
trace_probe_log_err(0, NO_EVENT_INFO);
goto parse_error;
}
if (!event) {
strscpy(buf1, argv[1], MAX_EVENT_NAME_LEN);
sanitize_event_name(buf1);
event = buf1;
}
if (!is_good_name(event) || !is_good_name(group))
goto parse_error;
sys_event = argv[1];
ret = traceprobe_parse_event_name(&sys_event, &sys_name, buf2,
sys_event - argv[1]);
if (ret || !sys_name)
goto parse_error;
if (!is_good_name(sys_event) || !is_good_name(sys_name))
goto parse_error;
mutex_lock(&event_mutex);
event_call = find_and_get_event(sys_name, sys_event);
@ -896,6 +901,8 @@ static int __trace_eprobe_create(int argc, const char *argv[])
if (IS_ERR(ep)) {
ret = PTR_ERR(ep);
if (ret == -ENODEV)
trace_probe_log_err(0, BAD_ATTACH_EVENT);
/* This must return -ENOMEM or missing event, else there is a bug */
WARN_ON_ONCE(ret != -ENOMEM && ret != -ENODEV);
ep = NULL;

View File

@ -4455,7 +4455,7 @@ static int create_hist_fields(struct hist_trigger_data *hist_data,
ret = parse_var_defs(hist_data);
if (ret)
goto out;
return ret;
ret = create_val_fields(hist_data, file);
if (ret)
@ -4466,8 +4466,7 @@ static int create_hist_fields(struct hist_trigger_data *hist_data,
goto out;
ret = create_key_fields(hist_data, file);
if (ret)
goto out;
out:
free_var_defs(hist_data);

View File

@ -567,7 +567,7 @@ static int user_event_set_call_visible(struct user_event *user, bool visible)
* to allow user_event files to be less locked down. The extreme case
* being "other" has read/write access to user_events_data/status.
*
* When not locked down, processes may not have have permissions to
* When not locked down, processes may not have permissions to
* add/remove calls themselves to tracefs. We need to temporarily
* switch to root file permission to allow for this scenario.
*/

View File

@ -163,7 +163,8 @@ static bool trace_kprobe_match(const char *system, const char *event,
{
struct trace_kprobe *tk = to_trace_kprobe(ev);
return strcmp(trace_probe_name(&tk->tp), event) == 0 &&
return (event[0] == '\0' ||
strcmp(trace_probe_name(&tk->tp), event) == 0) &&
(!system || strcmp(trace_probe_group_name(&tk->tp), system) == 0) &&
trace_kprobe_match_command_head(tk, argc, argv);
}
@ -708,11 +709,11 @@ static int __trace_kprobe_create(int argc, const char *argv[])
/*
* Argument syntax:
* - Add kprobe:
* p[:[GRP/]EVENT] [MOD:]KSYM[+OFFS]|KADDR [FETCHARGS]
* p[:[GRP/][EVENT]] [MOD:]KSYM[+OFFS]|KADDR [FETCHARGS]
* - Add kretprobe:
* r[MAXACTIVE][:[GRP/]EVENT] [MOD:]KSYM[+0] [FETCHARGS]
* r[MAXACTIVE][:[GRP/][EVENT]] [MOD:]KSYM[+0] [FETCHARGS]
* Or
* p:[GRP/]EVENT] [MOD:]KSYM[+0]%return [FETCHARGS]
* p[:[GRP/][EVENT]] [MOD:]KSYM[+0]%return [FETCHARGS]
*
* Fetch args:
* $retval : fetch return value
@ -739,6 +740,7 @@ static int __trace_kprobe_create(int argc, const char *argv[])
long offset = 0;
void *addr = NULL;
char buf[MAX_EVENT_NAME_LEN];
char gbuf[MAX_EVENT_NAME_LEN];
unsigned int flags = TPARG_FL_KERNEL;
switch (argv[0][0]) {
@ -833,11 +835,13 @@ static int __trace_kprobe_create(int argc, const char *argv[])
trace_probe_log_set_index(0);
if (event) {
ret = traceprobe_parse_event_name(&event, &group, buf,
ret = traceprobe_parse_event_name(&event, &group, gbuf,
event - argv[0]);
if (ret)
goto parse_error;
} else {
}
if (!event) {
/* Make a new event name */
if (symbol)
snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_%ld",

View File

@ -257,6 +257,10 @@ int traceprobe_parse_event_name(const char **pevent, const char **pgroup,
}
len = strlen(event);
if (len == 0) {
if (slash) {
*pevent = NULL;
return 0;
}
trace_probe_log_err(offset, NO_EVENT_NAME);
return -EINVAL;
} else if (len > MAX_EVENT_NAME_LEN) {

View File

@ -442,7 +442,10 @@ extern int traceprobe_define_arg_fields(struct trace_event_call *event_call,
C(FAIL_REG_PROBE, "Failed to register probe event"),\
C(DIFF_PROBE_TYPE, "Probe type is different from existing probe"),\
C(DIFF_ARG_TYPE, "Argument type or name is different from existing probe"),\
C(SAME_PROBE, "There is already the exact same probe event"),
C(SAME_PROBE, "There is already the exact same probe event"),\
C(NO_EVENT_INFO, "This requires both group and event name to attach"),\
C(BAD_ATTACH_EVENT, "Attached event does not exist"),\
C(BAD_ATTACH_ARG, "Attached event does not have this field"),
#undef C
#define C(a, b) TP_ERR_##a

View File

@ -313,7 +313,8 @@ static bool trace_uprobe_match(const char *system, const char *event,
{
struct trace_uprobe *tu = to_trace_uprobe(ev);
return strcmp(trace_probe_name(&tu->tp), event) == 0 &&
return (event[0] == '\0' ||
strcmp(trace_probe_name(&tu->tp), event) == 0) &&
(!system || strcmp(trace_probe_group_name(&tu->tp), system) == 0) &&
trace_uprobe_match_command_head(tu, argc, argv);
}
@ -533,7 +534,7 @@ static int register_trace_uprobe(struct trace_uprobe *tu)
/*
* Argument syntax:
* - Add uprobe: p|r[:[GRP/]EVENT] PATH:OFFSET[%return][(REF)] [FETCHARGS]
* - Add uprobe: p|r[:[GRP/][EVENT]] PATH:OFFSET[%return][(REF)] [FETCHARGS]
*/
static int __trace_uprobe_create(int argc, const char **argv)
{
@ -541,6 +542,7 @@ static int __trace_uprobe_create(int argc, const char **argv)
const char *event = NULL, *group = UPROBE_EVENT_SYSTEM;
char *arg, *filename, *rctr, *rctr_end, *tmp;
char buf[MAX_EVENT_NAME_LEN];
char gbuf[MAX_EVENT_NAME_LEN];
enum probe_print_type ptype;
struct path path;
unsigned long offset, ref_ctr_offset;
@ -645,11 +647,13 @@ static int __trace_uprobe_create(int argc, const char **argv)
/* setup a probe */
trace_probe_log_set_index(0);
if (event) {
ret = traceprobe_parse_event_name(&event, &group, buf,
ret = traceprobe_parse_event_name(&event, &group, gbuf,
event - argv[0]);
if (ret)
goto fail_address_parse;
} else {
}
if (!event) {
char *tail;
char *ptr;

View File

@ -28,8 +28,6 @@
#endif /* CONFIG_BATMAN_ADV_TRACING */
#define BATADV_MAX_MSG_LEN 256
TRACE_EVENT(batadv_dbg,
TP_PROTO(struct batadv_priv *bat_priv,
@ -40,16 +38,13 @@ TRACE_EVENT(batadv_dbg,
TP_STRUCT__entry(
__string(device, bat_priv->soft_iface->name)
__string(driver, KBUILD_MODNAME)
__dynamic_array(char, msg, BATADV_MAX_MSG_LEN)
__vstring(msg, vaf->fmt, vaf->va)
),
TP_fast_assign(
__assign_str(device, bat_priv->soft_iface->name);
__assign_str(driver, KBUILD_MODNAME);
WARN_ON_ONCE(vsnprintf(__get_dynamic_array(msg),
BATADV_MAX_MSG_LEN,
vaf->fmt,
*vaf->va) >= BATADV_MAX_MSG_LEN);
__assign_vstr(msg, vaf->fmt, vaf->va);
),
TP_printk(

View File

@ -24,13 +24,11 @@ DECLARE_EVENT_CLASS(mac80211_msg_event,
TP_ARGS(vaf),
TP_STRUCT__entry(
__dynamic_array(char, msg, MAX_MSG_LEN)
__vstring(msg, vaf->fmt, vaf->va)
),
TP_fast_assign(
WARN_ON_ONCE(vsnprintf(__get_dynamic_array(msg),
MAX_MSG_LEN, vaf->fmt,
*vaf->va) >= MAX_MSG_LEN);
__assign_vstr(msg, vaf->fmt, vaf->va);
),
TP_printk("%s", __get_str(msg))

View File

@ -19,9 +19,10 @@ static const char *random_strings[] = {
"One ring to rule them all"
};
static void simple_thread_func(int cnt)
static void do_simple_thread_func(int cnt, const char *fmt, ...)
{
unsigned long bitmask[1] = {0xdeadbeefUL};
va_list va;
int array[6];
int len = cnt % 5;
int i;
@ -33,9 +34,13 @@ static void simple_thread_func(int cnt)
array[i] = i + 1;
array[i] = 0;
va_start(va, fmt);
/* Silly tracepoints */
trace_foo_bar("hello", cnt, array, random_strings[len],
current->cpus_ptr);
current->cpus_ptr, fmt, &va);
va_end(va);
trace_foo_with_template_simple("HELLO", cnt);
@ -48,6 +53,11 @@ static void simple_thread_func(int cnt)
trace_foo_rel_loc("Hello __rel_loc", cnt, bitmask);
}
static void simple_thread_func(int cnt)
{
do_simple_thread_func(cnt, "iter=%d", cnt);
}
static int simple_thread(void *arg)
{
int cnt = 0;

View File

@ -141,6 +141,27 @@
* In most cases, the __assign_str() macro will take the same
* parameters as the __string() macro had to declare the string.
*
* __vstring: This is similar to __string() but instead of taking a
* dynamic length, it takes a variable list va_list 'va' variable.
* Some event callers already have a message from parameters saved
* in a va_list. Passing in the format and the va_list variable
* will save just enough on the ring buffer for that string.
* Note, the va variable used is a pointer to a va_list, not
* to the va_list directly.
*
* (va_list *va)
*
* __vstring(foo, fmt, va) is similar to: vsnprintf(foo, fmt, va)
*
* To assign the string, use the helper macro __assign_vstr().
*
* __assign_vstr(foo, fmt, va);
*
* In most cases, the __assign_vstr() macro will take the same
* parameters as the __vstring() macro had to declare the string.
* Use __get_str() to retrieve the __vstring() just like it would for
* __string().
*
* __string_len: This is a helper to a __dynamic_array, but it understands
* that the array has characters in it, and with the combined
* use of __assign_str_len(), it will allocate 'len' + 1 bytes
@ -256,9 +277,10 @@ TRACE_DEFINE_ENUM(TRACE_SAMPLE_ZOO);
TRACE_EVENT(foo_bar,
TP_PROTO(const char *foo, int bar, const int *lst,
const char *string, const struct cpumask *mask),
const char *string, const struct cpumask *mask,
const char *fmt, va_list *va),
TP_ARGS(foo, bar, lst, string, mask),
TP_ARGS(foo, bar, lst, string, mask, fmt, va),
TP_STRUCT__entry(
__array( char, foo, 10 )
@ -266,6 +288,7 @@ TRACE_EVENT(foo_bar,
__dynamic_array(int, list, __length_of(lst))
__string( str, string )
__bitmask( cpus, num_possible_cpus() )
__vstring( vstr, fmt, va )
),
TP_fast_assign(
@ -274,10 +297,11 @@ TRACE_EVENT(foo_bar,
memcpy(__get_dynamic_array(list), lst,
__length_of(lst) * sizeof(int));
__assign_str(str, string);
__assign_vstr(vstr, fmt, va);
__assign_bitmask(cpus, cpumask_bits(mask), num_possible_cpus());
),
TP_printk("foo %s %d %s %s %s %s (%s)", __entry->foo, __entry->bar,
TP_printk("foo %s %d %s %s %s %s (%s) %s", __entry->foo, __entry->bar,
/*
* Notice here the use of some helper functions. This includes:
@ -321,7 +345,7 @@ TRACE_EVENT(foo_bar,
__print_array(__get_dynamic_array(list),
__get_dynamic_array_len(list) / sizeof(int),
sizeof(int)),
__get_str(str), __get_bitmask(cpus))
__get_str(str), __get_bitmask(cpus), __get_str(vstr))
);
/*

View File

@ -8,7 +8,7 @@ This script parses a trace provided by the function tracer in
kernel/trace/trace_functions.c
The resulted trace is processed into a tree to produce a more human
view of the call stack by drawing textual but hierarchical tree of
calls. Only the functions's names and the the call time are provided.
calls. Only the functions's names and the call time are provided.
Usage:
Be sure that you have CONFIG_FUNCTION_TRACER

View File

@ -1,7 +1,7 @@
#!/bin/sh
# SPDX-License-Identifier: GPL-2.0
# description: Generic dynamic event - add/remove eprobe events
# requires: dynamic_events events/syscalls/sys_enter_openat "e[:[<group>/]<event>] <attached-group>.<attached-event> [<args>]":README
# requires: dynamic_events events/syscalls/sys_enter_openat "<attached-group>.<attached-event> [<args>]":README
echo 0 > events/enable
@ -87,4 +87,11 @@ echo "-:eprobes/$EPROBE $SYSTEM/$EVENT $OPTIONS" >> dynamic_events
! grep -q "$EPROBE" dynamic_events
! test -d events/eprobes/$EPROBE
if grep -q "e\[:\[<group>/]\[<event>]]" README; then
echo "e:mygroup/ $SYSTEM/$EVENT $OPTIONS" >> dynamic_events
test -d events/mygroup
echo "-:mygroup/" >> dynamic_events
! test -d events/mygroup
fi
clear_trace

View File

@ -23,4 +23,11 @@ grep -q myevent1 dynamic_events
echo > dynamic_events
if grep -q "p\[:\[<group>/]\[<event>]]" README; then
echo "p:mygroup/ $PLACE" >> dynamic_events
test -d events/mygroup
echo "-:mygroup/" >> dynamic_events
! test -d events/mygroup
fi
clear_trace

View File

@ -21,7 +21,7 @@ check_error 'p:^/bar vfs_read' # NO_GROUP_NAME
check_error 'p:^12345678901234567890123456789012345678901234567890123456789012345/bar vfs_read' # GROUP_TOO_LONG
check_error 'p:^foo.1/bar vfs_read' # BAD_GROUP_NAME
check_error 'p:foo/^ vfs_read' # NO_EVENT_NAME
check_error 'p:^ vfs_read' # NO_EVENT_NAME
check_error 'p:foo/^12345678901234567890123456789012345678901234567890123456789012345 vfs_read' # EVENT_TOO_LONG
check_error 'p:foo/^bar.1 vfs_read' # BAD_EVENT_NAME

View File

@ -0,0 +1,26 @@
INSTALL=install
prefix ?= /usr
bindir ?= $(prefix)/bin
mandir ?= $(prefix)/share/man
miscdir ?= $(prefix)/share/dot2
srcdir ?= $(prefix)/src
PYLIB ?= $(shell python3 -c 'import sysconfig; print (sysconfig.get_path("purelib"))')
.PHONY: all
all:
.PHONY: clean
clean:
.PHONY: install
install:
$(INSTALL) automata.py -D -m 644 $(DESTDIR)$(PYLIB)/dot2/automata.py
$(INSTALL) dot2c.py -D -m 644 $(DESTDIR)$(PYLIB)/dot2/dot2c.py
$(INSTALL) dot2c -D -m 755 $(DESTDIR)$(bindir)/
$(INSTALL) dot2k.py -D -m 644 $(DESTDIR)$(PYLIB)/dot2/dot2k.py
$(INSTALL) dot2k -D -m 755 $(DESTDIR)$(bindir)/
mkdir -p ${miscdir}/
cp -rp dot2k_templates $(DESTDIR)$(miscdir)/

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#!/usr/bin/env python3
# SPDX-License-Identifier: GPL-2.0-only
#
# Copyright (C) 2019-2022 Red Hat, Inc. Daniel Bristot de Oliveira <bristot@kernel.org>
#
# Automata object: parse an automata in dot file digraph format into a python object
#
# For further information, see:
# Documentation/trace/rv/deterministic_automata.rst
import ntpath
class Automata:
"""Automata class: Reads a dot file and part it as an automata.
Attributes:
dot_file: A dot file with an state_automaton definition.
"""
invalid_state_str = "INVALID_STATE"
def __init__(self, file_path):
self.__dot_path = file_path
self.name = self.__get_model_name()
self.__dot_lines = self.__open_dot()
self.states, self.initial_state, self.final_states = self.__get_state_variables()
self.events = self.__get_event_variables()
self.function = self.__create_matrix()
def __get_model_name(self):
basename = ntpath.basename(self.__dot_path)
if basename.endswith(".dot") == False:
print("not a dot file")
raise Exception("not a dot file: %s" % self.__dot_path)
model_name = basename[0:-4]
if model_name.__len__() == 0:
raise Exception("not a dot file: %s" % self.__dot_path)
return model_name
def __open_dot(self):
cursor = 0
dot_lines = []
try:
dot_file = open(self.__dot_path)
except:
raise Exception("Cannot open the file: %s" % self.__dot_path)
dot_lines = dot_file.read().splitlines()
dot_file.close()
# checking the first line:
line = dot_lines[cursor].split()
if (line[0] != "digraph") and (line[1] != "state_automaton"):
raise Exception("Not a valid .dot format: %s" % self.__dot_path)
else:
cursor += 1
return dot_lines
def __get_cursor_begin_states(self):
cursor = 0
while self.__dot_lines[cursor].split()[0] != "{node":
cursor += 1
return cursor
def __get_cursor_begin_events(self):
cursor = 0
while self.__dot_lines[cursor].split()[0] != "{node":
cursor += 1
while self.__dot_lines[cursor].split()[0] == "{node":
cursor += 1
# skip initial state transition
cursor += 1
return cursor
def __get_state_variables(self):
# wait for node declaration
states = []
final_states = []
has_final_states = False
cursor = self.__get_cursor_begin_states()
# process nodes
while self.__dot_lines[cursor].split()[0] == "{node":
line = self.__dot_lines[cursor].split()
raw_state = line[-1]
# "enabled_fired"}; -> enabled_fired
state = raw_state.replace('"', '').replace('};', '').replace(',','_')
if state[0:7] == "__init_":
initial_state = state[7:]
else:
states.append(state)
if self.__dot_lines[cursor].__contains__("doublecircle") == True:
final_states.append(state)
has_final_states = True
if self.__dot_lines[cursor].__contains__("ellipse") == True:
final_states.append(state)
has_final_states = True
cursor += 1
states = sorted(set(states))
states.remove(initial_state)
# Insert the initial state at the bein og the states
states.insert(0, initial_state)
if has_final_states == False:
final_states.append(initial_state)
return states, initial_state, final_states
def __get_event_variables(self):
# here we are at the begin of transitions, take a note, we will return later.
cursor = self.__get_cursor_begin_events()
events = []
while self.__dot_lines[cursor][1] == '"':
# transitions have the format:
# "all_fired" -> "both_fired" [ label = "disable_irq" ];
# ------------ event is here ------------^^^^^
if self.__dot_lines[cursor].split()[1] == "->":
line = self.__dot_lines[cursor].split()
event = line[-2].replace('"','')
# when a transition has more than one lables, they are like this
# "local_irq_enable\nhw_local_irq_enable_n"
# so split them.
event = event.replace("\\n", " ")
for i in event.split():
events.append(i)
cursor += 1
return sorted(set(events))
def __create_matrix(self):
# transform the array into a dictionary
events = self.events
states = self.states
events_dict = {}
states_dict = {}
nr_event = 0
for event in events:
events_dict[event] = nr_event
nr_event += 1
nr_state = 0
for state in states:
states_dict[state] = nr_state
nr_state += 1
# declare the matrix....
matrix = [[ self.invalid_state_str for x in range(nr_event)] for y in range(nr_state)]
# and we are back! Let's fill the matrix
cursor = self.__get_cursor_begin_events()
while self.__dot_lines[cursor][1] == '"':
if self.__dot_lines[cursor].split()[1] == "->":
line = self.__dot_lines[cursor].split()
origin_state = line[0].replace('"','').replace(',','_')
dest_state = line[2].replace('"','').replace(',','_')
possible_events = line[-2].replace('"','').replace("\\n", " ")
for event in possible_events.split():
matrix[states_dict[origin_state]][events_dict[event]] = dest_state
cursor += 1
return matrix

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#!/usr/bin/env python3
# SPDX-License-Identifier: GPL-2.0-only
#
# Copyright (C) 2019-2022 Red Hat, Inc. Daniel Bristot de Oliveira <bristot@kernel.org>
#
# dot2c: parse an automata in dot file digraph format into a C
#
# This program was written in the development of this paper:
# de Oliveira, D. B. and Cucinotta, T. and de Oliveira, R. S.
# "Efficient Formal Verification for the Linux Kernel." International
# Conference on Software Engineering and Formal Methods. Springer, Cham, 2019.
#
# For further information, see:
# Documentation/trace/rv/deterministic_automata.rst
if __name__ == '__main__':
from dot2 import dot2c
import argparse
import sys
parser = argparse.ArgumentParser(description='dot2c: converts a .dot file into a C structure')
parser.add_argument('dot_file', help='The dot file to be converted')
args = parser.parse_args()
d = dot2c.Dot2c(args.dot_file)
d.print_model_classic()

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#!/usr/bin/env python3
# SPDX-License-Identifier: GPL-2.0-only
#
# Copyright (C) 2019-2022 Red Hat, Inc. Daniel Bristot de Oliveira <bristot@kernel.org>
#
# dot2c: parse an automata in dot file digraph format into a C
#
# This program was written in the development of this paper:
# de Oliveira, D. B. and Cucinotta, T. and de Oliveira, R. S.
# "Efficient Formal Verification for the Linux Kernel." International
# Conference on Software Engineering and Formal Methods. Springer, Cham, 2019.
#
# For further information, see:
# Documentation/trace/rv/deterministic_automata.rst
from dot2.automata import Automata
class Dot2c(Automata):
enum_suffix = ""
enum_states_def = "states"
enum_events_def = "events"
struct_automaton_def = "automaton"
var_automaton_def = "aut"
def __init__(self, file_path):
super().__init__(file_path)
self.line_length = 100
def __buff_to_string(self, buff):
string = ""
for line in buff:
string = string + line + "\n"
# cut off the last \n
return string[:-1]
def __get_enum_states_content(self):
buff = []
buff.append("\t%s%s = 0," % (self.initial_state, self.enum_suffix))
for state in self.states:
if state != self.initial_state:
buff.append("\t%s%s," % (state, self.enum_suffix))
buff.append("\tstate_max%s" % (self.enum_suffix))
return buff
def get_enum_states_string(self):
buff = self.__get_enum_states_content()
return self.__buff_to_string(buff)
def format_states_enum(self):
buff = []
buff.append("enum %s {" % self.enum_states_def)
buff.append(self.get_enum_states_string())
buff.append("};\n")
return buff
def __get_enum_events_content(self):
buff = []
first = True
for event in self.events:
if first:
buff.append("\t%s%s = 0," % (event, self.enum_suffix))
first = False
else:
buff.append("\t%s%s," % (event, self.enum_suffix))
buff.append("\tevent_max%s" % self.enum_suffix)
return buff
def get_enum_events_string(self):
buff = self.__get_enum_events_content()
return self.__buff_to_string(buff)
def format_events_enum(self):
buff = []
buff.append("enum %s {" % self.enum_events_def)
buff.append(self.get_enum_events_string())
buff.append("};\n")
return buff
def get_minimun_type(self):
min_type = "unsigned char"
if self.states.__len__() > 255:
min_type = "unsigned short"
if self.states.__len__() > 65535:
min_type = "unsigned int"
if self.states.__len__() > 1000000:
raise Exception("Too many states: %d" % self.states.__len__())
return min_type
def format_automaton_definition(self):
min_type = self.get_minimun_type()
buff = []
buff.append("struct %s {" % self.struct_automaton_def)
buff.append("\tchar *state_names[state_max%s];" % (self.enum_suffix))
buff.append("\tchar *event_names[event_max%s];" % (self.enum_suffix))
buff.append("\t%s function[state_max%s][event_max%s];" % (min_type, self.enum_suffix, self.enum_suffix))
buff.append("\t%s initial_state;" % min_type)
buff.append("\tbool final_states[state_max%s];" % (self.enum_suffix))
buff.append("};\n")
return buff
def format_aut_init_header(self):
buff = []
buff.append("struct %s %s = {" % (self.struct_automaton_def, self.var_automaton_def))
return buff
def __get_string_vector_per_line_content(self, buff):
first = True
string = ""
for entry in buff:
if first:
string = string + "\t\t\"" + entry
first = False;
else:
string = string + "\",\n\t\t\"" + entry
string = string + "\""
return string
def get_aut_init_events_string(self):
return self.__get_string_vector_per_line_content(self.events)
def get_aut_init_states_string(self):
return self.__get_string_vector_per_line_content(self.states)
def format_aut_init_events_string(self):
buff = []
buff.append("\t.event_names = {")
buff.append(self.get_aut_init_events_string())
buff.append("\t},")
return buff
def format_aut_init_states_string(self):
buff = []
buff.append("\t.state_names = {")
buff.append(self.get_aut_init_states_string())
buff.append("\t},")
return buff
def __get_max_strlen_of_states(self):
max_state_name = max(self.states, key = len).__len__()
return max(max_state_name, self.invalid_state_str.__len__())
def __get_state_string_length(self):
maxlen = self.__get_max_strlen_of_states() + self.enum_suffix.__len__()
return "%" + str(maxlen) + "s"
def get_aut_init_function(self):
nr_states = self.states.__len__()
nr_events = self.events.__len__()
buff = []
strformat = self.__get_state_string_length()
for x in range(nr_states):
line = "\t\t{ "
for y in range(nr_events):
next_state = self.function[x][y]
if next_state != self.invalid_state_str:
next_state = self.function[x][y] + self.enum_suffix
if y != nr_events-1:
line = line + strformat % next_state + ", "
else:
line = line + strformat % next_state + " },"
buff.append(line)
return self.__buff_to_string(buff)
def format_aut_init_function(self):
buff = []
buff.append("\t.function = {")
buff.append(self.get_aut_init_function())
buff.append("\t},")
return buff
def get_aut_init_initial_state(self):
return self.initial_state
def format_aut_init_initial_state(self):
buff = []
initial_state = self.get_aut_init_initial_state()
buff.append("\t.initial_state = " + initial_state + self.enum_suffix + ",")
return buff
def get_aut_init_final_states(self):
line = ""
first = True
for state in self.states:
if first == False:
line = line + ', '
else:
first = False
if self.final_states.__contains__(state):
line = line + '1'
else:
line = line + '0'
return line
def format_aut_init_final_states(self):
buff = []
buff.append("\t.final_states = { %s }," % self.get_aut_init_final_states())
return buff
def __get_automaton_initialization_footer_string(self):
footer = "};\n"
return footer
def format_aut_init_footer(self):
buff = []
buff.append(self.__get_automaton_initialization_footer_string())
return buff
def format_invalid_state(self):
buff = []
buff.append("#define %s state_max%s\n" % (self.invalid_state_str, self.enum_suffix))
return buff
def format_model(self):
buff = []
buff += self.format_states_enum()
buff += self.format_invalid_state()
buff += self.format_events_enum()
buff += self.format_automaton_definition()
buff += self.format_aut_init_header()
buff += self.format_aut_init_states_string()
buff += self.format_aut_init_events_string()
buff += self.format_aut_init_function()
buff += self.format_aut_init_initial_state()
buff += self.format_aut_init_final_states()
buff += self.format_aut_init_footer()
return buff
def print_model_classic(self):
buff = self.format_model()
print(self.__buff_to_string(buff))

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#!/usr/bin/env python3
# SPDX-License-Identifier: GPL-2.0-only
#
# Copyright (C) 2019-2022 Red Hat, Inc. Daniel Bristot de Oliveira <bristot@kernel.org>
#
# dot2k: transform dot files into a monitor for the Linux kernel.
#
# For further information, see:
# Documentation/trace/rv/da_monitor_synthesis.rst
if __name__ == '__main__':
from dot2.dot2k import dot2k
import argparse
import ntpath
import os
import platform
import sys
import sys
import argparse
parser = argparse.ArgumentParser(description='transform .dot file into kernel rv monitor')
parser.add_argument('-d', "--dot", dest="dot_file", required=True)
parser.add_argument('-t', "--monitor_type", dest="monitor_type", required=True)
parser.add_argument('-n', "--model_name", dest="model_name", required=False)
parser.add_argument("-D", "--description", dest="description", required=False)
params = parser.parse_args()
print("Opening and parsing the dot file %s" % params.dot_file)
try:
monitor=dot2k(params.dot_file, params.monitor_type)
except Exception as e:
print('Error: '+ str(e))
print("Sorry : :-(")
sys.exit(1)
# easier than using argparse action.
if params.model_name != None:
print(params.model_name)
print("Writing the monitor into the directory %s" % monitor.name)
monitor.print_files()
print("Almost done, checklist")
print(" - Edit the %s/%s.c to add the instrumentation" % (monitor.name, monitor.name))
print(" - Edit include/trace/events/rv.h to add the tracepoint entry")
print(" - Move it to the kernel's monitor directory")
print(" - Edit kernel/trace/rv/Makefile")
print(" - Edit kernel/trace/rv/Kconfig")

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#!/usr/bin/env python3
# SPDX-License-Identifier: GPL-2.0-only
#
# Copyright (C) 2019-2022 Red Hat, Inc. Daniel Bristot de Oliveira <bristot@kernel.org>
#
# dot2k: transform dot files into a monitor for the Linux kernel.
#
# For further information, see:
# Documentation/trace/rv/da_monitor_synthesis.rst
from dot2.dot2c import Dot2c
import platform
import os
class dot2k(Dot2c):
monitor_types = { "global" : 1, "per_cpu" : 2, "per_task" : 3 }
monitor_templates_dir = "dot2k/rv_templates/"
monitor_type = "per_cpu"
def __init__(self, file_path, MonitorType):
super().__init__(file_path)
self.monitor_type = self.monitor_types.get(MonitorType)
if self.monitor_type == None:
raise Exception("Unknown monitor type: %s" % MonitorType)
self.monitor_type = MonitorType
self.__fill_rv_templates_dir()
self.main_c = self.__open_file(self.monitor_templates_dir + "main_" + MonitorType + ".c")
self.enum_suffix = "_%s" % self.name
def __fill_rv_templates_dir(self):
if os.path.exists(self.monitor_templates_dir) == True:
return
if platform.system() != "Linux":
raise Exception("I can only run on Linux.")
kernel_path = "/lib/modules/%s/build/tools/verification/dot2/dot2k_templates/" % (platform.release())
if os.path.exists(kernel_path) == True:
self.monitor_templates_dir = kernel_path
return
if os.path.exists("/usr/share/dot2/dot2k_templates/") == True:
self.monitor_templates_dir = "/usr/share/dot2/dot2k_templates/"
return
raise Exception("Could not find the template directory, do you have the kernel source installed?")
def __open_file(self, path):
try:
fd = open(path)
except OSError:
raise Exception("Cannot open the file: %s" % path)
content = fd.read()
return content
def __buff_to_string(self, buff):
string = ""
for line in buff:
string = string + line + "\n"
# cut off the last \n
return string[:-1]
def fill_tracepoint_handlers_skel(self):
buff = []
for event in self.events:
buff.append("static void handle_%s(void *data, /* XXX: fill header */)" % event)
buff.append("{")
if self.monitor_type == "per_task":
buff.append("\tstruct task_struct *p = /* XXX: how do I get p? */;");
buff.append("\tda_handle_event_%s(p, %s%s);" % (self.name, event, self.enum_suffix));
else:
buff.append("\tda_handle_event_%s(%s%s);" % (self.name, event, self.enum_suffix));
buff.append("}")
buff.append("")
return self.__buff_to_string(buff)
def fill_tracepoint_attach_probe(self):
buff = []
for event in self.events:
buff.append("\trv_attach_trace_probe(\"%s\", /* XXX: tracepoint */, handle_%s);" % (self.name, event))
return self.__buff_to_string(buff)
def fill_tracepoint_detach_helper(self):
buff = []
for event in self.events:
buff.append("\trv_detach_trace_probe(\"%s\", /* XXX: tracepoint */, handle_%s);" % (self.name, event))
return self.__buff_to_string(buff)
def fill_main_c(self):
main_c = self.main_c
min_type = self.get_minimun_type()
nr_events = self.events.__len__()
tracepoint_handlers = self.fill_tracepoint_handlers_skel()
tracepoint_attach = self.fill_tracepoint_attach_probe()
tracepoint_detach = self.fill_tracepoint_detach_helper()
main_c = main_c.replace("MIN_TYPE", min_type)
main_c = main_c.replace("MODEL_NAME", self.name)
main_c = main_c.replace("NR_EVENTS", str(nr_events))
main_c = main_c.replace("TRACEPOINT_HANDLERS_SKEL", tracepoint_handlers)
main_c = main_c.replace("TRACEPOINT_ATTACH", tracepoint_attach)
main_c = main_c.replace("TRACEPOINT_DETACH", tracepoint_detach)
return main_c
def fill_model_h_header(self):
buff = []
buff.append("/*")
buff.append(" * Automatically generated C representation of %s automaton" % (self.name))
buff.append(" * For further information about this format, see kernel documentation:")
buff.append(" * Documentation/trace/rv/deterministic_automata.rst")
buff.append(" */")
buff.append("")
return buff
def fill_model_h(self):
#
# Adjust the definition names
#
self.enum_states_def = "states_%s" % self.name
self.enum_events_def = "events_%s" % self.name
self.struct_automaton_def = "automaton_%s" % self.name
self.var_automaton_def = "automaton_%s" % self.name
buff = self.fill_model_h_header()
buff += self.format_model()
return self.__buff_to_string(buff)
def __create_directory(self):
try:
os.mkdir(self.name)
except FileExistsError:
return
except:
print("Fail creating the output dir: %s" % self.name)
def __create_file(self, file_name, content):
path = "%s/%s" % (self.name, file_name)
try:
file = open(path, 'w')
except FileExistsError:
return
except:
print("Fail creating file: %s" % path)
file.write(content)
file.close()
def __get_main_name(self):
path = "%s/%s" % (self.name, "main.c")
if os.path.exists(path) == False:
return "main.c"
return "__main.c"
def print_files(self):
main_c = self.fill_main_c()
model_h = self.fill_model_h()
self.__create_directory()
path = "%s.c" % self.name
self.__create_file(path, main_c)
path = "%s.h" % self.name
self.__create_file(path, model_h)

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// SPDX-License-Identifier: GPL-2.0
#include <linux/ftrace.h>
#include <linux/tracepoint.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/rv.h>
#include <rv/instrumentation.h>
#include <rv/da_monitor.h>
#define MODULE_NAME "MODEL_NAME"
/*
* XXX: include required tracepoint headers, e.g.,
* #include <trace/events/sched.h>
*/
#include <trace/events/rv.h>
/*
* This is the self-generated part of the monitor. Generally, there is no need
* to touch this section.
*/
#include "MODEL_NAME.h"
/*
* Declare the deterministic automata monitor.
*
* The rv monitor reference is needed for the monitor declaration.
*/
struct rv_monitor rv_MODEL_NAME;
DECLARE_DA_MON_GLOBAL(MODEL_NAME, MIN_TYPE);
/*
* This is the instrumentation part of the monitor.
*
* This is the section where manual work is required. Here the kernel events
* are translated into model's event.
*
*/
TRACEPOINT_HANDLERS_SKEL
static int enable_MODEL_NAME(void)
{
int retval;
retval = da_monitor_init_MODEL_NAME();
if (retval)
return retval;
TRACEPOINT_ATTACH
return 0;
}
static void disable_MODEL_NAME(void)
{
rv_MODEL_NAME.enabled = 0;
TRACEPOINT_DETACH
da_monitor_destroy_MODEL_NAME();
}
/*
* This is the monitor register section.
*/
struct rv_monitor rv_MODEL_NAME = {
.name = "MODEL_NAME",
.description = "auto-generated MODEL_NAME",
.enable = enable_MODEL_NAME,
.disable = disable_MODEL_NAME,
.reset = da_monitor_reset_all_MODEL_NAME,
.enabled = 0,
};
static int register_MODEL_NAME(void)
{
rv_register_monitor(&rv_MODEL_NAME);
return 0;
}
static void unregister_MODEL_NAME(void)
{
rv_unregister_monitor(&rv_MODEL_NAME);
}
module_init(register_MODEL_NAME);
module_exit(unregister_MODEL_NAME);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("dot2k: auto-generated");
MODULE_DESCRIPTION("MODEL_NAME");

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// SPDX-License-Identifier: GPL-2.0
#include <linux/ftrace.h>
#include <linux/tracepoint.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/rv.h>
#include <rv/instrumentation.h>
#include <rv/da_monitor.h>
#define MODULE_NAME "MODEL_NAME"
/*
* XXX: include required tracepoint headers, e.g.,
* #include <linux/trace/events/sched.h>
*/
#include <trace/events/rv.h>
/*
* This is the self-generated part of the monitor. Generally, there is no need
* to touch this section.
*/
#include "MODEL_NAME.h"
/*
* Declare the deterministic automata monitor.
*
* The rv monitor reference is needed for the monitor declaration.
*/
struct rv_monitor rv_MODEL_NAME;
DECLARE_DA_MON_PER_CPU(MODEL_NAME, MIN_TYPE);
/*
* This is the instrumentation part of the monitor.
*
* This is the section where manual work is required. Here the kernel events
* are translated into model's event.
*
*/
TRACEPOINT_HANDLERS_SKEL
static int enable_MODEL_NAME(void)
{
int retval;
retval = da_monitor_init_MODEL_NAME();
if (retval)
return retval;
TRACEPOINT_ATTACH
return 0;
}
static void disable_MODEL_NAME(void)
{
rv_MODEL_NAME.enabled = 0;
TRACEPOINT_DETACH
da_monitor_destroy_MODEL_NAME();
}
/*
* This is the monitor register section.
*/
struct rv_monitor rv_MODEL_NAME = {
.name = "MODEL_NAME",
.description = "auto-generated MODEL_NAME",
.enable = enable_MODEL_NAME,
.disable = disable_MODEL_NAME,
.reset = da_monitor_reset_all_MODEL_NAME,
.enabled = 0,
};
static int register_MODEL_NAME(void)
{
rv_register_monitor(&rv_MODEL_NAME);
return 0;
}
static void unregister_MODEL_NAME(void)
{
rv_unregister_monitor(&rv_MODEL_NAME);
}
module_init(register_MODEL_NAME);
module_exit(unregister_MODEL_NAME);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("dot2k: auto-generated");
MODULE_DESCRIPTION("MODEL_NAME");

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// SPDX-License-Identifier: GPL-2.0
#include <linux/ftrace.h>
#include <linux/tracepoint.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/rv.h>
#include <rv/instrumentation.h>
#include <rv/da_monitor.h>
#define MODULE_NAME "MODEL_NAME"
/*
* XXX: include required tracepoint headers, e.g.,
* #include <linux/trace/events/sched.h>
*/
#include <trace/events/rv.h>
/*
* This is the self-generated part of the monitor. Generally, there is no need
* to touch this section.
*/
#include "MODEL_NAME.h"
/*
* Declare the deterministic automata monitor.
*
* The rv monitor reference is needed for the monitor declaration.
*/
struct rv_monitor rv_MODEL_NAME;
DECLARE_DA_MON_PER_TASK(MODEL_NAME, MIN_TYPE);
/*
* This is the instrumentation part of the monitor.
*
* This is the section where manual work is required. Here the kernel events
* are translated into model's event.
*
*/
TRACEPOINT_HANDLERS_SKEL
static int enable_MODEL_NAME(void)
{
int retval;
retval = da_monitor_init_MODEL_NAME();
if (retval)
return retval;
TRACEPOINT_ATTACH
return 0;
}
static void disable_MODEL_NAME(void)
{
rv_MODEL_NAME.enabled = 0;
TRACEPOINT_DETACH
da_monitor_destroy_MODEL_NAME();
}
/*
* This is the monitor register section.
*/
struct rv_monitor rv_MODEL_NAME = {
.name = "MODEL_NAME",
.description = "auto-generated MODEL_NAME",
.enable = enable_MODEL_NAME,
.disable = disable_MODEL_NAME,
.reset = da_monitor_reset_all_MODEL_NAME,
.enabled = 0,
};
static int register_MODEL_NAME(void)
{
rv_register_monitor(&rv_MODEL_NAME);
return 0;
}
static void unregister_MODEL_NAME(void)
{
rv_unregister_monitor(&rv_MODEL_NAME);
}
module_init(register_MODEL_NAME);
module_exit(unregister_MODEL_NAME);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("dot2k: auto-generated");
MODULE_DESCRIPTION("MODEL_NAME");

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digraph state_automaton {
{node [shape = circle] "non_preemptive"};
{node [shape = plaintext, style=invis, label=""] "__init_preemptive"};
{node [shape = doublecircle] "preemptive"};
{node [shape = circle] "preemptive"};
"__init_preemptive" -> "preemptive";
"non_preemptive" [label = "non_preemptive"];
"non_preemptive" -> "non_preemptive" [ label = "sched_waking" ];
"non_preemptive" -> "preemptive" [ label = "preempt_enable" ];
"preemptive" [label = "preemptive"];
"preemptive" -> "non_preemptive" [ label = "preempt_disable" ];
{ rank = min ;
"__init_preemptive";
"preemptive";
}
}

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digraph state_automaton {
{node [shape = plaintext, style=invis, label=""] "__init_not_running"};
{node [shape = ellipse] "not_running"};
{node [shape = plaintext] "not_running"};
{node [shape = plaintext] "running"};
"__init_not_running" -> "not_running";
"not_running" [label = "not_running", color = green3];
"not_running" -> "not_running" [ label = "wakeup" ];
"not_running" -> "running" [ label = "switch_in" ];
"running" [label = "running"];
"running" -> "not_running" [ label = "switch_out" ];
{ rank = min ;
"__init_not_running";
"not_running";
}
}