On Fri, Apr 3, 2020 at 6:20 AM Andrey Konovalov andreyknvl@google.com wrote:
On Thu, Apr 2, 2020 at 10:46 PM 'Patricia Alfonso' via kasan-dev kasan-dev@googlegroups.com 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;return 0;+}
+static void kasan_test_exit(struct kunit *test) +{
kasan_restore_multi_shot(multishot);/* Restore panic_on_warn */Nit: no need for this comment, I think it's clear that here we're restoring stuff we saved in kasan_test_init().
Okay!
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"); \Is res going to be == &resource here? If so, no need to call kunit_find_named_resource().
You're right. Thanks for the suggestion!
kasan_data = res->data; \KUNIT_EXPECT_EQ(test, \kasan_data->report_expected, \kasan_data->report_found); \Nit: no need to add kasan_data var, just use resource.data->report_expected.
I can probably just use fail_data->report_expected, actually.
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)
This isn't used outside of report.c, right? Then _static_ void kasan_update_kunit_status().
Correct.
+{
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");Do this before the if above, and then check if (!resource), will save you a call to kunit_find_named_resource().
kasan_data = resource->data;kasan_data->report_found = true;No need for kasan_data var (if it can't be NULL or something), just do:
resource->data->report_found = true;
The compiler seems to really hate this... mm/kasan/report.c: In function ‘kasan_update_kunit_status’: mm/kasan/report.c:471:16: warning: dereferencing ‘void *’ pointer 471 | resource->data->report_found = true; | ^~ mm/kasan/report.c:471:16: error: request for member ‘report_found’ in something not a structure or union
Do you know how to fix this? I don't think I fully understand the error.
+} +#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;