Documentation: dev-tools: Add a section for static analysis tools

Complement the Kernel Testing Guide documentation page by adding a
section about static analysis tools.

Signed-off-by: Marcelo Schmitt <marcelo.schmitt1@gmail.com>
Acked-by: Daniel Latypov <dlatypov@google.com>
Acked-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Julia Lawall <julia.lawall@inria.fr>
Reviewed-by: David Gow <davidgow@google.com>
Reviewed-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
This commit is contained in:
Marcelo Schmitt 2022-03-30 18:49:33 -03:00 committed by Jonathan Corbet
parent 2c2de6f2e2
commit 12379401c0

View File

@ -115,3 +115,34 @@ that none of these errors are occurring during the test.
Some of these tools integrate with KUnit or kselftest and will
automatically fail tests if an issue is detected.
Static Analysis Tools
=====================
In addition to testing a running kernel, one can also analyze kernel source code
directly (**at compile time**) using **static analysis** tools. The tools
commonly used in the kernel allow one to inspect the whole source tree or just
specific files within it. They make it easier to detect and fix problems during
the development process.
Sparse can help test the kernel by performing type-checking, lock checking,
value range checking, in addition to reporting various errors and warnings while
examining the code. See the Documentation/dev-tools/sparse.rst documentation
page for details on how to use it.
Smatch extends Sparse and provides additional checks for programming logic
mistakes such as missing breaks in switch statements, unused return values on
error checking, forgetting to set an error code in the return of an error path,
etc. Smatch also has tests against more serious issues such as integer
overflows, null pointer dereferences, and memory leaks. See the project page at
http://smatch.sourceforge.net/.
Coccinelle is another static analyzer at our disposal. Coccinelle is often used
to aid refactoring and collateral evolution of source code, but it can also help
to avoid certain bugs that occur in common code patterns. The types of tests
available include API tests, tests for correct usage of kernel iterators, checks
for the soundness of free operations, analysis of locking behavior, and further
tests known to help keep consistent kernel usage. See the
Documentation/dev-tools/coccinelle.rst documentation page for details.
Beware, though, that static analysis tools suffer from **false positives**.
Errors and warns need to be evaluated carefully before attempting to fix them.