On Thu, 2 Apr 2020, Patricia Alfonso wrote:
Integrate KASAN into KUnit testing framework. - Fail tests when KASAN reports an error that is not expected - Use KUNIT_EXPECT_KASAN_FAIL to expect a KASAN error in KASAN tests - Expected KASAN reports pass tests and are still printed when run without kunit_tool (kunit_tool still bypasses the report due to the test passing) - KUnit struct in current task used to keep track of the current test from KASAN code
Make use of "[PATCH v3 kunit-next 1/2] kunit: generalize kunit_resource API beyond allocated resources" and "[PATCH v3 kunit-next 2/2] kunit: add support for named resources" from Alan Maguire [1] - A named resource is added to a test when a KASAN report is expected - This resource contains a struct for kasan_data containing booleans representing if a KASAN report is expected and if a KASAN report is found
[1] (https://lore.kernel.org/linux-kselftest/1583251361-12748-1-git-send-email-al...)
Signed-off-by: Patricia Alfonso trishalfonso@google.com Reviewed-by: Dmitry Vyukov dvyukov@google.com
include/kunit/test.h | 5 ++++ include/linux/kasan.h | 6 +++++ lib/kunit/test.c | 13 ++++++---- lib/test_kasan.c | 56 +++++++++++++++++++++++++++++++++++++++---- mm/kasan/report.c | 30 +++++++++++++++++++++++ 5 files changed, 101 insertions(+), 9 deletions(-)
diff --git a/include/kunit/test.h b/include/kunit/test.h index ac59d18e6bab..1dc3d118f64b 100644 --- a/include/kunit/test.h +++ b/include/kunit/test.h @@ -225,6 +225,11 @@ struct kunit { struct list_head resources; /* Protected by lock. */ }; +static inline void kunit_set_failure(struct kunit *test) +{
- WRITE_ONCE(test->success, false);
+}
void kunit_init_test(struct kunit *test, const char *name, char *log); int kunit_run_tests(struct kunit_suite *suite); diff --git a/include/linux/kasan.h b/include/linux/kasan.h index 5cde9e7c2664..148eaef3e003 100644 --- a/include/linux/kasan.h +++ b/include/linux/kasan.h @@ -14,6 +14,12 @@ struct task_struct; #include <asm/kasan.h> #include <asm/pgtable.h> +/* kasan_data struct is used in KUnit tests for KASAN expected failures */ +struct kunit_kasan_expectation {
- bool report_expected;
- bool report_found;
+};
extern unsigned char kasan_early_shadow_page[PAGE_SIZE]; extern pte_t kasan_early_shadow_pte[PTRS_PER_PTE]; extern pmd_t kasan_early_shadow_pmd[PTRS_PER_PMD]; diff --git a/lib/kunit/test.c b/lib/kunit/test.c index 2cb7c6220a00..030a3281591e 100644 --- a/lib/kunit/test.c +++ b/lib/kunit/test.c @@ -10,16 +10,12 @@ #include <linux/kernel.h> #include <linux/kref.h> #include <linux/sched/debug.h> +#include <linux/sched.h> #include "debugfs.h" #include "string-stream.h" #include "try-catch-impl.h" -static void kunit_set_failure(struct kunit *test) -{
- WRITE_ONCE(test->success, false);
-}
static void kunit_print_tap_version(void) { static bool kunit_has_printed_tap_version; @@ -288,6 +284,10 @@ static void kunit_try_run_case(void *data) struct kunit_suite *suite = ctx->suite; struct kunit_case *test_case = ctx->test_case; +#if (IS_ENABLED(CONFIG_KASAN) && IS_ENABLED(CONFIG_KUNIT))
- current->kunit_test = test;
+#endif /* IS_ENABLED(CONFIG_KASAN) && IS_ENABLED(CONFIG_KUNIT) */
- /*
- kunit_run_case_internal may encounter a fatal error; if it does,
- abort will be called, this thread will exit, and finally the parent
@@ -603,6 +603,9 @@ void kunit_cleanup(struct kunit *test) spin_unlock(&test->lock); kunit_remove_resource(test, res); } +#if (IS_ENABLED(CONFIG_KASAN) && IS_ENABLED(CONFIG_KUNIT))
- current->kunit_test = NULL;
+#endif /* IS_ENABLED(CONFIG_KASAN) && IS_ENABLED(CONFIG_KUNIT)*/ } EXPORT_SYMBOL_GPL(kunit_cleanup); diff --git a/lib/test_kasan.c b/lib/test_kasan.c index 3872d250ed2c..dbfa0875ee09 100644 --- a/lib/test_kasan.c +++ b/lib/test_kasan.c @@ -23,12 +23,60 @@ #include <asm/page.h> -/*
- Note: test functions are marked noinline so that their names appear in
- reports.
+#include <kunit/test.h>
+static struct kunit_resource resource; +static struct kunit_kasan_expectation fail_data; +static bool multishot; +static int orig_panic_on_warn;
+static int kasan_test_init(struct kunit *test) +{
- /*
* Temporarily enable multi-shot mode and set panic_on_warn=0.* Otherwise, we'd only get a report for the first case.*/- multishot = kasan_save_enable_multi_shot();
- orig_panic_on_warn = panic_on_warn;
- panic_on_warn = 0;
When I build kunit and test_kasan as a module, I'm seeing
ERROR: "panic_on_warn" [lib/test_kasan.ko] undefined!
Looks like this variable isn't exported (unlike panic_timeout).
Is there an in-kernel API to read sysctl values we could use here that would be safe for module and builtin access maybe?
Alan
- return 0;
+}
+static void kasan_test_exit(struct kunit *test) +{
- kasan_restore_multi_shot(multishot);
- /* Restore panic_on_warn */
- panic_on_warn = orig_panic_on_warn;
+}
+/**
- KUNIT_EXPECT_KASAN_FAIL() - Causes a test failure when the expression does
- not cause a KASAN error. This uses a KUnit resource named "kasan_data." Do
- Do not use this name for a KUnit resource outside here.
*/
+#define KUNIT_EXPECT_KASAN_FAIL(test, condition) do { \
- struct kunit_resource *res; \
- struct kunit_kasan_expectation *kasan_data; \
- fail_data.report_expected = true; \
- fail_data.report_found = false; \
- kunit_add_named_resource(test, \
NULL, \NULL, \&resource, \"kasan_data", &fail_data); \- condition; \
- res = kunit_find_named_resource(test, "kasan_data"); \
- kasan_data = res->data; \
- KUNIT_EXPECT_EQ(test, \
kasan_data->report_expected, \kasan_data->report_found); \- kunit_put_resource(res); \
+} while (0) -static noinline void __init kmalloc_oob_right(void) { char *ptr; size_t size = 123; diff --git a/mm/kasan/report.c b/mm/kasan/report.c index 5ef9f24f566b..497477c4b679 100644 --- a/mm/kasan/report.c +++ b/mm/kasan/report.c @@ -32,6 +32,8 @@ #include <asm/sections.h> +#include <kunit/test.h>
#include "kasan.h" #include "../slab.h" @@ -455,12 +457,35 @@ static bool report_enabled(void) return !test_and_set_bit(KASAN_BIT_REPORTED, &kasan_flags); } +#if IS_ENABLED(CONFIG_KUNIT) +void kasan_update_kunit_status(struct kunit *cur_test) +{
- struct kunit_resource *resource;
- struct kunit_kasan_expectation *kasan_data;
- if (!kunit_find_named_resource(cur_test, "kasan_data")) {
kunit_set_failure(cur_test);return;- }
- resource = kunit_find_named_resource(cur_test, "kasan_data");
- kasan_data = resource->data;
- kasan_data->report_found = true;
+} +#endif /* IS_ENABLED(CONFIG_KUNIT) */
void kasan_report_invalid_free(void *object, unsigned long ip) { unsigned long flags; u8 tag = get_tag(object); object = reset_tag(object);
+#if IS_ENABLED(CONFIG_KUNIT)
- if (current->kunit_test)
kasan_update_kunit_status(current->kunit_test);+#endif /* IS_ENABLED(CONFIG_KUNIT) */
- start_report(&flags); pr_err("BUG: KASAN: double-free or invalid-free in %pS\n", (void *)ip); print_tags(tag, object);
@@ -481,6 +506,11 @@ void __kasan_report(unsigned long addr, size_t size, bool is_write, unsigned lon if (likely(!report_enabled())) return; +#if IS_ENABLED(CONFIG_KUNIT)
- if (current->kunit_test)
kasan_update_kunit_status(current->kunit_test);+#endif /* IS_ENABLED(CONFIG_KUNIT) */
- disable_trace_on_warning();
tagged_addr = (void *)addr; -- 2.26.0.292.g33ef6b2f38-goog