rv: Fix addition on an uninitialized variable 'run'

The variable run is not initialized however it is being accumulated
by the return value from the call to ikm_run_monitor. Fix this by
initializing run to zero at the start of the function.

Link: https://lkml.kernel.org/r/20230424094730.105313-1-colin.i.king@gmail.com

Fixes: 4bc4b131d44c ("rv: Add rv tool")

Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Acked-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

tools/rv: Add in-kernel monitor interface

Add the ability to control and trace in-kernel monitors. This is
a generic interface, it will check for existing monitors and enable
standard setup, like enabling reactors.

For example:

# rv list
wip wakeup in preemptive per-cpu testing monitor. [OFF]
wwnr wakeup while not running per-task testing model. [OFF]

# rv mon wwnr --help
rv version 6.1.0-rc4: help

usage: rv mon wwnr [-h] [-q] [-r reactor] [-s] [-v]
-h/--help: print this menu and the reactor list
-r/--reactor 'reactor': enables the 'reactor'
-s/--self: when tracing (-t), also trace rv command
-t/--trace: trace monitor's event
-v/--verbose: print debug messages

available reactors: nop printk panic

# rv mon wwnr --trace
<TASK>-PID [CPU] TYPE ID STATE x EVENT -> NEXT_STATE FINAL
| | | | | | | | |
rv-3613 [001] event 3613 running x switch_out -> not_running Y
sshd-1248 [005] event 1248 running x switch_out -> not_running Y
<idle>-0 [005] event 71 not_running x wakeup -> not_running Y
<idle>-0 [005] event 71 not_running x switch_in -> running N
kcompactd0-71 [005] event 71 running x switch_out -> not_running Y
<idle>-0 [000] event 860 not_running x wakeup -> not_running Y
<idle>-0 [000] event 860 not_running x switch_in -> running N
systemd-oomd-860 [000] event 860 running x switch_out -> not_running Y
<idle>-0 [000] event 860 not_running x wakeup -> not_running Y
<idle>-0 [000] event 860 not_running x switch_in -> running N
systemd-oomd-860 [000] event 860 running x switch_out -> not_running Y
<idle>-0 [005] event 71 not_running x wakeup -> not_running Y
<idle>-0 [005] event 71 not_running x switch_in -> running N
kcompactd0-71 [005] event 71 running x switch_out -> not_running Y
<idle>-0 [000] event 860 not_running x wakeup -> not_running Y
<idle>-0 [000] event 860 not_running x switch_in -> running N
systemd-oomd-860 [000] event 860 running x switch_out -> not_running Y
<idle>-0 [001] event 3613 not_running x wakeup -> not_running Y

Link: https://lkml.kernel.org/r/1e57547e3acadda6e23949b2672c89e76ec2ec42.1668180100.git.bristot@kernel.org

Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

rv: Add rv tool

This is the (user-space) runtime verification tool, named rv.

This tool aims to be the interface for in-kernel rv monitors, as
well as the home for monitors in user-space (online asynchronous),
and in *eBPF.

The tool receives a command as the first argument, the current
commands are:

list - list all available monitors
mon - run a given monitor

Each monitor is an independent piece of software inside the
tool and can have their own arguments.

There is no monitor implemented in this patch, it only
adds the basic structure of the tool, based on rtla.

# rv --help
rv version 6.1.0-rc4: help

usage: rv command [-h] [command_options]

-h/--help: print this menu

command: run one of the following command:
list: list all available monitors
mon: run a monitor

[command options]: each command has its own set of options
run rv command -h for further information

*dot2bpf is the next patch set, depends on this, doing cleanups.

Link: https://lkml.kernel.org/r/fb51184f3b95aea0d7bfdc33ec09f4153aee84fa.1668180100.git.bristot@kernel.org

Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>