On Sat, Apr 2, 2022 at 12:35 AM 'David Gow' via KUnit Development kunit-dev@googlegroups.com wrote:
KUnit's test-managed resources can be created in two ways:
- Using the kunit_add_resource() family of functions, which accept a struct kunit_resource pointer, typically allocated statically or on the stack during the test.
- Using the kunit_alloc_resource() family of functions, which allocate a struct kunit_resource using kzalloc() behind the scenes.
Both of these families of functions accept a 'free' function to be called when the resource is finally disposed of.
At present, KUnit will kfree() the resource if this 'free' function is specified, and will not if it is NULL. However, this can lead kunit_alloc_resource() to leak memory (if no 'free' function is passed in), or kunit_add_resource() to incorrectly kfree() memory which was allocated by some other means (on the stack, as part of a larger allocation, etc), if a 'free' function is provided.
Instead, always kfree() if the resource was allocated with kunit_alloc_resource(), and never kfree() if it was passed into kunit_add_resource() by the user. (If the user of kunit_add_resource() wishes the resource be kfree()ed, they can call kfree() on the resource from within the 'free' function.
This is implemented by adding a 'should_free' member to struct kunit_resource and setting it appropriately. To facilitate this, the various resource add/alloc functions have been refactored somewhat, making them all call a __kunit_add_resource() helper after setting the 'should_free' member appropriately. In the process, all other functions have been made static inline functions.
Signed-off-by: David Gow davidgow@google.com Tested-by: Daniel Latypov dlatypov@google.com
Reviewed-by: Brendan Higgins brendanhiggins@google.com