On Thu, Feb 27, 2020 at 6:04 AM Alan Maguire alan.maguire@oracle.com wrote:
Sorry for the delay in reviews. I have been preoccupied by some Google internal stuff.
On Wed, 26 Feb 2020, Patricia Alfonso wrote:
Integrate KASAN into KUnit testing framework.
This is a great idea! Some comments/suggestions below...
- Fail tests when KASAN reports an error that is not expected
- Use KUNIT_EXPECT_KASAN_FAIL to expect a KASAN error in KASAN tests
- KUnit struct added to current task to keep track of the current test
from KASAN code
- Booleans representing if a KASAN report is expected and if a KASAN
report is found added to kunit struct
- This prints "line# has passed" or "line# has failed"
Signed-off-by: Patricia Alfonso trishalfonso@google.com
If anyone has any suggestions on how best to print the failure messages, please share!
One issue I have found while testing this is the allocation fails in kmalloc_pagealloc_oob_right() sometimes, but not consistently. This does cause the test to fail on the KUnit side, as expected, but it seems to skip all the tests before this one because the output starts with this failure instead of with the first test, kmalloc_oob_right().
include/kunit/test.h | 24 ++++++++++++++++++++++++ include/linux/sched.h | 7 ++++++- lib/kunit/test.c | 7 ++++++- mm/kasan/report.c | 19 +++++++++++++++++++ tools/testing/kunit/kunit_kernel.py | 2 +- 5 files changed, 56 insertions(+), 3 deletions(-)
diff --git a/include/kunit/test.h b/include/kunit/test.h index 2dfb550c6723..2e388f8937f3 100644 --- a/include/kunit/test.h +++ b/include/kunit/test.h @@ -21,6 +21,8 @@ struct kunit_resource; typedef int (*kunit_resource_init_t)(struct kunit_resource *, void *); typedef void (*kunit_resource_free_t)(struct kunit_resource *);
+void kunit_set_failure(struct kunit *test);
/**
- struct kunit_resource - represents a *test managed resource*
- @allocation: for the user to store arbitrary data.
@@ -191,6 +193,9 @@ struct kunit { * protect it with some type of lock. */ struct list_head resources; /* Protected by lock. */
bool kasan_report_expected;bool kasan_report_found;};
Is this needed here? You're testing something pretty specific so it seems wrong to add to the generic kunit resource unless there's a good reason. I see the code around setting these values in mm/kasan/report.c, but I wonder if we could do something more generic.
How about the concept of a static resource (assuming a dynamically allocated one is out because it messes with memory allocation tests)? Something like this:
#define kunit_add_static_resource(test, resource_ptr, resource_field) \ do { \ spin_lock(&test->lock); \ (resource_ptr)->resource_field.init = NULL; \ (resource_ptr)->resource_field.free = NULL; \ list_add_tail(&(resource_ptr)->resource_field, \ &test->resources); \ spin_unlock(&test->lock); \ } while (0)
Within your kasan code you could then create a kasan-specific structure that embends a kunit_resource, and contains the values you need:
struct kasan_report_resource { struct kunit_resource res; bool kasan_report_expected; bool kasan_report_found; };
(One thing we'd need to do for such static resources is fix kunit_resource_free() to check if there's a free() function, and if not assume a static resource)
If you then create an init() function associated with your kunit suite (which will be run for every case) it can do this:
int kunit_kasan_test_init(struct kunit *test) { kunit_add_static_resource(test, &my_kasan_report_resource, res); ... }
The above should also be used to initialize current->kasan_unit_test instead of doing that in kunit_try_run_case(). With those changes, you don't (I think) need to change anything in core kunit (assuming support for static resources).
To retrieve the resource during tests or in kasan context, the method seems to be to use kunit_resource_find(). However, that requires a match function which seems a bit heavyweight for the static case. We should probably have a default "find by name" or similar function here, and add an optional "name" field to kunit resources to simplify things. Anyway here you'd use something like:
kasan_report_resource = kunit_resource_find(test, matchfn, NULL, matchdata);Are there any barriers to taking this sort of approach (apart from the support for static resources not being there yet)?
This is a really interesting idea, Alan! I never imagined kunit_resources being used this way, and I like it. I saw you sent some patches to implement this stuff, so I will withhold further comments on that here.