From: Patricia Alfonso trishalfonso@google.com
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 Signed-off-by: David Gow davidgow@google.com Reviewed-by: Andrey Konovalov andreyknvl@google.com Reviewed-by: Dmitry Vyukov dvyukov@google.com Acked-by: Brendan Higgins brendanhiggins@google.com --- include/kunit/test.h | 5 +++++ include/linux/kasan.h | 6 ++++++ lib/kunit/test.c | 13 +++++++----- lib/test_kasan.c | 47 +++++++++++++++++++++++++++++++++++++++++-- mm/kasan/report.c | 32 +++++++++++++++++++++++++++++ 5 files changed, 96 insertions(+), 7 deletions(-)
diff --git a/include/kunit/test.h b/include/kunit/test.h index 59f3144f009a..3391f38389f8 100644 --- a/include/kunit/test.h +++ b/include/kunit/test.h @@ -224,6 +224,11 @@ 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 087fba34b209..30d343b4a40a 100644 --- a/include/linux/kasan.h +++ b/include/linux/kasan.h @@ -14,6 +14,12 @@ struct task_struct; #include <linux/pgtable.h> #include <asm/kasan.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 c36037200310..dcc35fd30d95 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 @@ -602,6 +602,9 @@ 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 53e953bb1d1d..58bffadd8367 100644 --- a/lib/test_kasan.c +++ b/lib/test_kasan.c @@ -23,6 +23,8 @@
#include <asm/page.h>
+#include <kunit/test.h> + #include "../mm/kasan/kasan.h"
#define OOB_TAG_OFF (IS_ENABLED(CONFIG_KASAN_GENERIC) ? 0 : KASAN_SHADOW_SCALE_SIZE) @@ -32,14 +34,55 @@ * are not eliminated as dead code. */
-int kasan_int_result; void *kasan_ptr_result; +int kasan_int_result; + +static struct kunit_resource resource; +static struct kunit_kasan_expectation fail_data; +static bool multishot; + +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(); + + return 0; +} + +static void kasan_test_exit(struct kunit *test) +{ + kasan_restore_multi_shot(multishot); +} + +/** + * 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 { \ + fail_data.report_expected = true; \ + fail_data.report_found = false; \ + kunit_add_named_resource(test, \ + NULL, \ + NULL, \ + &resource, \ + "kasan_data", &fail_data); \ + condition; \ + KUNIT_EXPECT_EQ(test, \ + fail_data.report_expected, \ + fail_data.report_found); \ +} while (0) + +
/* * Note: test functions are marked noinline so that their names appear in * reports. */ - static noinline void __init kmalloc_oob_right(void) { char *ptr; diff --git a/mm/kasan/report.c b/mm/kasan/report.c index 4f49fa6cd1aa..e2c14b10bc81 100644 --- a/mm/kasan/report.c +++ b/mm/kasan/report.c @@ -33,6 +33,8 @@
#include <asm/sections.h>
+#include <kunit/test.h> + #include "kasan.h" #include "../slab.h"
@@ -464,12 +466,37 @@ static bool report_enabled(void) return !test_and_set_bit(KASAN_BIT_REPORTED, &kasan_flags); }
+#if IS_ENABLED(CONFIG_KUNIT) +static void kasan_update_kunit_status(struct kunit *cur_test) +{ + struct kunit_resource *resource; + struct kunit_kasan_expectation *kasan_data; + + resource = kunit_find_named_resource(cur_test, "kasan_data"); + + if (!resource) { + kunit_set_failure(cur_test); + return; + } + + kasan_data = (struct kunit_kasan_expectation *)resource->data; + kasan_data->report_found = true; + kunit_put_resource(resource); +} +#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); @@ -488,6 +515,11 @@ static void __kasan_report(unsigned long addr, size_t size, bool is_write, void *untagged_addr; unsigned long flags;
+#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;