Commit Graph

3 Commits

Author SHA1 Message Date
Daniel Bristot de Oliveira
61ec586bc0 tools/rv: Fix curr_reactor uninitialized variable
clang is reporting:

$ make HOSTCC=clang CC=clang LLVM_IAS=1

clang -O -g -DVERSION=\"6.8.0-rc3\" -flto=auto -fexceptions
	-fstack-protector-strong -fasynchronous-unwind-tables
	-fstack-clash-protection  -Wall -Werror=format-security
	-Wp,-D_FORTIFY_SOURCE=2 -Wp,-D_GLIBCXX_ASSERTIONS
	$(pkg-config --cflags libtracefs)  -I include
	-c -o src/in_kernel.o src/in_kernel.c
[...]

src/in_kernel.c:227:6: warning: variable 'curr_reactor' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized]
  227 |         if (!end)
      |             ^~~~
src/in_kernel.c:242:9: note: uninitialized use occurs here
  242 |         return curr_reactor;
      |                ^~~~~~~~~~~~
src/in_kernel.c:227:2: note: remove the 'if' if its condition is always false
  227 |         if (!end)
      |         ^~~~~~~~~
  228 |                 goto out_free;
      |                 ~~~~~~~~~~~~~
src/in_kernel.c:221:6: warning: variable 'curr_reactor' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized]
  221 |         if (!start)
      |             ^~~~~~
src/in_kernel.c:242:9: note: uninitialized use occurs here
  242 |         return curr_reactor;
      |                ^~~~~~~~~~~~
src/in_kernel.c:221:2: note: remove the 'if' if its condition is always false
  221 |         if (!start)
      |         ^~~~~~~~~~~
  222 |                 goto out_free;
      |                 ~~~~~~~~~~~~~
src/in_kernel.c:215:20: note: initialize the variable 'curr_reactor' to silence this warning
  215 |         char *curr_reactor;
      |                           ^
      |                            = NULL
2 warnings generated.

Which is correct. Setting curr_reactor to NULL avoids the problem.

Link: https://lkml.kernel.org/r/3a35551149e5ee0cb0950035afcb8082c3b5d05b.1707217097.git.bristot@kernel.org

Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Bill Wendling <morbo@google.com>
Cc: Justin Stitt <justinstitt@google.com>
Cc: Donald Zickus <dzickus@redhat.com>
Fixes: 6d60f89691 ("tools/rv: Add in-kernel monitor interface")
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
2024-02-12 09:58:36 +01:00
zhang songyi
a37380ef8b tools/rv: Remove unneeded semicolon
The semicolon after the "}" is unneeded.

Link: https://lore.kernel.org/linux-trace-devel/202212191431057948891@zte.com.cn

Signed-off-by: zhang songyi <zhang.songyi@zte.com.cn>
Acked-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-01-31 19:21:12 -05:00
Daniel Bristot de Oliveira
6d60f89691 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>
2022-12-09 18:06:24 -05:00