trace/osnoise: Make 'noise' variable s64 in run_osnoise()

Browse source

Dab Carpenter reported that:

 The patch bce29ac9ce: "trace: Add osnoise tracer" from Jun 22,
 2021, leads to the following static checker warning:

	kernel/trace/trace_osnoise.c:1103 run_osnoise()
	warn: unsigned 'noise' is never less than zero.

In this part of the code:

  1100                  /*
  1101                   * This shouldn't happen.
  1102                   */
  1103                  if (noise < 0) {
                            ^^^^^^^^^
  1104                          osnoise_taint("negative noise!");
  1105                          goto out;
  1106                  }
  1107

And the static checker is right because 'noise' is u64.

Make noise s64 and keep the check. It is important to check if
the time read is behaving correctly - so we can trust the results.

I also re-arranged some variable declarations.

Link: https://lkml.kernel.org/r/acd7cd6e7d56b798a298c3bc8139a390b3c4ab52.1624986368.git.bristot@redhat.com

Cc: Ingo Molnar <mingo@redhat.com>
Cc: Daniel Bristot de Oliveira <bristot@redhat.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: linux-kernel@vger.kernel.org
Fixes: bce29ac9ce ("trace: Add osnoise tracer")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

...

This commit is contained in:

Daniel Bristot de Oliveira 2021-06-29 19:10:26 +02:00 • committed by Steven Rostedt (VMware)

parent 9913d5745b

commit 19c3eaa722

1 changed files with 3 additions and 2 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

5

kernel/trace/trace_osnoise.c

View file