On Fri, Apr 3, 2020 at 7:17 PM Patricia Alfonso <trishalfonso@xxxxxxxxxx> wrote: > > On Fri, Apr 3, 2020 at 6:20 AM Andrey Konovalov <andreyknvl@xxxxxxxxxx> wrote: > > > > On Thu, Apr 2, 2020 at 10:46 PM 'Patricia Alfonso' via kasan-dev > > <kasan-dev@xxxxxxxxxxxxxxxx> 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-alan.maguire@xxxxxxxxxx/T/#t) > > > > > > Signed-off-by: Patricia Alfonso <trishalfonso@xxxxxxxxxx> > > > Reviewed-by: Dmitry Vyukov <dvyukov@xxxxxxxxxx> > > > --- > > > 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. Ah, resource->data is a void *, missed that. Let's keep the kasan_data var then, but do explicit casting: kasan_data = (struct kunit_kasan_expectation *)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; > > -- > Best, > Patricia
