Complement the Kernel Testing Guide documentation page by adding a section about static analysis tools. Signed-off-by: Marcelo Schmitt <marcelo.schmitt1@xxxxxxxxx> Acked-by: Daniel Latypov <dlatypov@xxxxxxxxxx> Acked-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx> Acked-by: Julia Lawall <julia.lawall@xxxxxxxx> Reviewed-by: David Gow <davidgow@xxxxxxxxxx> Reviewed-by: Shuah Khan <skhan@xxxxxxxxxxxxxxxxxxx> --- Change log v2 -> v3: - Added Julia's acknowledgment tag Change log v1 -> v2: - Brought generic tool characteristics to the intro paragraph - Made explicit that these tools run at compile time - Added a note of caution about false positives - Updated Coccinelle info to make it sound better and be more skimmable Documentation/dev-tools/testing-overview.rst | 31 ++++++++++++++++++++ 1 file changed, 31 insertions(+) diff --git a/Documentation/dev-tools/testing-overview.rst b/Documentation/dev-tools/testing-overview.rst index 65feb81edb14..b5e02dd3fd94 100644 --- a/Documentation/dev-tools/testing-overview.rst +++ b/Documentation/dev-tools/testing-overview.rst @@ -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. -- 2.35.1
