[PATCH 0/2] kasan: few improvements on kunit tests

[PATCH 0/2] kasan: few improvements on kunit tests

[Sabyrzhan Tasbolatov]

This patch series addresses the issue [1] with KASAN symbols used
in the Kunit test, but exported as EXPORT_SYMBOL_GPL.

Also a small tweak of marking kasan_atomics() as KUNIT_CASE_SLOW
to avoid kunit report that the test should be marked as slow.

Both patches have been tested on (CONFIG_KASAN_KUNIT_TEST=y):
- x86_64: CONFIG_KASAN=y
- arm64: CONFIG_KASAN_HW_TAGS=y

[1] https://lore.kernel.org/linux-mm/ZxigQIF59s3_h5PS@infradead.org/T/

EXPORT_SYMBOL_IF_KUNIT

Sabyrzhan Tasbolatov (2):
  kasan: use EXPORT_SYMBOL_IF_KUNIT to export symbols for kunit tests
  kasan: change kasan_atomics kunit test as KUNIT_CASE_SLOW

 mm/kasan/hw_tags.c      |  7 ++++---
 mm/kasan/kasan_test_c.c |  4 +++-
 mm/kasan/report.c       | 17 +++++++++--------
 3 files changed, 16 insertions(+), 12 deletions(-)

-- 
2.34.1

[PATCH 1/2] kasan: use EXPORT_SYMBOL_IF_KUNIT to export symbols

[Sabyrzhan Tasbolatov]

Replace EXPORT_SYMBOL_GPL with EXPORT_SYMBOL_IF_KUNIT to mark the
symbols as visible only if CONFIG_KUNIT is enabled.

KASAN Kunit test should import the namespace EXPORTED_FOR_KUNIT_TESTING
to use these marked symbols.

Reported-by: Andrey Konovalov <andreyknvl@gmail.com>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218315
Signed-off-by: Sabyrzhan Tasbolatov <snovitoll@gmail.com>
---
 mm/kasan/hw_tags.c      |  7 ++++---
 mm/kasan/kasan_test_c.c |  2 ++
 mm/kasan/report.c       | 17 +++++++++--------
 3 files changed, 15 insertions(+), 11 deletions(-)

diff --git a/mm/kasan/hw_tags.c b/mm/kasan/hw_tags.c
index 9958ebc15d38..ccd66c7a4081 100644
--- a/mm/kasan/hw_tags.c
+++ b/mm/kasan/hw_tags.c
@@ -8,6 +8,7 @@
 
 #define pr_fmt(fmt) "kasan: " fmt
 
+#include <kunit/visibility.h>
 #include <linux/init.h>
 #include <linux/kasan.h>
 #include <linux/kernel.h>
@@ -394,12 +395,12 @@ void kasan_enable_hw_tags(void)
 
 #if IS_ENABLED(CONFIG_KASAN_KUNIT_TEST)
 
-EXPORT_SYMBOL_GPL(kasan_enable_hw_tags);
+EXPORT_SYMBOL_IF_KUNIT(kasan_enable_hw_tags);
 
-void kasan_force_async_fault(void)
+VISIBLE_IF_KUNIT void kasan_force_async_fault(void)
 {
 	hw_force_async_tag_fault();
 }
-EXPORT_SYMBOL_GPL(kasan_force_async_fault);
+EXPORT_SYMBOL_IF_KUNIT(kasan_force_async_fault);
 
 #endif
diff --git a/mm/kasan/kasan_test_c.c b/mm/kasan/kasan_test_c.c
index a181e4780d9d..3e495c09342e 100644
--- a/mm/kasan/kasan_test_c.c
+++ b/mm/kasan/kasan_test_c.c
@@ -33,6 +33,8 @@
 
 #define OOB_TAG_OFF (IS_ENABLED(CONFIG_KASAN_GENERIC) ? 0 : KASAN_GRANULE_SIZE)
 
+MODULE_IMPORT_NS(EXPORTED_FOR_KUNIT_TESTING);
+
 static bool multishot;
 
 /* Fields set based on lines observed in the console. */
diff --git a/mm/kasan/report.c b/mm/kasan/report.c
index b48c768acc84..e5bc4e3ee198 100644
--- a/mm/kasan/report.c
+++ b/mm/kasan/report.c
@@ -10,6 +10,7 @@
  */
 
 #include <kunit/test.h>
+#include <kunit/visibility.h>
 #include <linux/bitops.h>
 #include <linux/ftrace.h>
 #include <linux/init.h>
@@ -134,18 +135,18 @@ static bool report_enabled(void)
 
 #if IS_ENABLED(CONFIG_KASAN_KUNIT_TEST) || IS_ENABLED(CONFIG_KASAN_MODULE_TEST)
 
-bool kasan_save_enable_multi_shot(void)
+VISIBLE_IF_KUNIT bool kasan_save_enable_multi_shot(void)
 {
 	return test_and_set_bit(KASAN_BIT_MULTI_SHOT, &kasan_flags);
 }
-EXPORT_SYMBOL_GPL(kasan_save_enable_multi_shot);
+EXPORT_SYMBOL_IF_KUNIT(kasan_save_enable_multi_shot);
 
-void kasan_restore_multi_shot(bool enabled)
+VISIBLE_IF_KUNIT void kasan_restore_multi_shot(bool enabled)
 {
 	if (!enabled)
 		clear_bit(KASAN_BIT_MULTI_SHOT, &kasan_flags);
 }
-EXPORT_SYMBOL_GPL(kasan_restore_multi_shot);
+EXPORT_SYMBOL_IF_KUNIT(kasan_restore_multi_shot);
 
 #endif
 
@@ -157,17 +158,17 @@ EXPORT_SYMBOL_GPL(kasan_restore_multi_shot);
  */
 static bool kasan_kunit_executing;
 
-void kasan_kunit_test_suite_start(void)
+VISIBLE_IF_KUNIT void kasan_kunit_test_suite_start(void)
 {
 	WRITE_ONCE(kasan_kunit_executing, true);
 }
-EXPORT_SYMBOL_GPL(kasan_kunit_test_suite_start);
+EXPORT_SYMBOL_IF_KUNIT(kasan_kunit_test_suite_start);
 
-void kasan_kunit_test_suite_end(void)
+VISIBLE_IF_KUNIT void kasan_kunit_test_suite_end(void)
 {
 	WRITE_ONCE(kasan_kunit_executing, false);
 }
-EXPORT_SYMBOL_GPL(kasan_kunit_test_suite_end);
+EXPORT_SYMBOL_IF_KUNIT(kasan_kunit_test_suite_end);
 
 static bool kasan_kunit_test_suite_executing(void)
 {
-- 
2.34.1

[PATCH 2/2] kasan: change kasan_atomics kunit test as KUNIT_CASE_SLOW

[Sabyrzhan Tasbolatov]

During running KASAN Kunit tests with CONFIG_KASAN enabled, the
following "warning" is reported by kunit framework:

	# kasan_atomics: Test should be marked slow (runtime: 2.604703115s)

It took 2.6 seconds on my PC (Intel(R) Core(TM) i7-7700K CPU @ 4.20GHz),
apparently, due to multiple atomic checks in kasan_atomics_helper().

Let's mark it with KUNIT_CASE_SLOW which reports now as:

	# kasan_atomics.speed: slow

Signed-off-by: Sabyrzhan Tasbolatov <snovitoll@gmail.com>
---
 mm/kasan/kasan_test_c.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/kasan/kasan_test_c.c b/mm/kasan/kasan_test_c.c
index 3e495c09342e..3946fc89a979 100644
--- a/mm/kasan/kasan_test_c.c
+++ b/mm/kasan/kasan_test_c.c
@@ -2020,7 +2020,7 @@ static struct kunit_case kasan_kunit_test_cases[] = {
 	KUNIT_CASE(kasan_strings),
 	KUNIT_CASE(kasan_bitops_generic),
 	KUNIT_CASE(kasan_bitops_tags),
-	KUNIT_CASE(kasan_atomics),
+	KUNIT_CASE_SLOW(kasan_atomics),
 	KUNIT_CASE(vmalloc_helpers_tags),
 	KUNIT_CASE(vmalloc_oob),
 	KUNIT_CASE(vmap_tags),
-- 
2.34.1

Re: [PATCH 1/2] kasan: use EXPORT_SYMBOL_IF_KUNIT to export symbols

[Andrey Konovalov]

On Fri, Nov 1, 2024 at 7:40 PM Sabyrzhan Tasbolatov <snovitoll@gmail.com> wrote:
>
> Replace EXPORT_SYMBOL_GPL with EXPORT_SYMBOL_IF_KUNIT to mark the
> symbols as visible only if CONFIG_KUNIT is enabled.
>
> KASAN Kunit test should import the namespace EXPORTED_FOR_KUNIT_TESTING
> to use these marked symbols.
>
> Reported-by: Andrey Konovalov <andreyknvl@gmail.com>
> Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218315
> Signed-off-by: Sabyrzhan Tasbolatov <snovitoll@gmail.com>
> ---
>  mm/kasan/hw_tags.c      |  7 ++++---
>  mm/kasan/kasan_test_c.c |  2 ++
>  mm/kasan/report.c       | 17 +++++++++--------
>  3 files changed, 15 insertions(+), 11 deletions(-)
>
> diff --git a/mm/kasan/hw_tags.c b/mm/kasan/hw_tags.c
> index 9958ebc15d38..ccd66c7a4081 100644
> --- a/mm/kasan/hw_tags.c
> +++ b/mm/kasan/hw_tags.c
> @@ -8,6 +8,7 @@
>
>  #define pr_fmt(fmt) "kasan: " fmt
>
> +#include <kunit/visibility.h>
>  #include <linux/init.h>
>  #include <linux/kasan.h>
>  #include <linux/kernel.h>
> @@ -394,12 +395,12 @@ void kasan_enable_hw_tags(void)
>
>  #if IS_ENABLED(CONFIG_KASAN_KUNIT_TEST)
>
> -EXPORT_SYMBOL_GPL(kasan_enable_hw_tags);
> +EXPORT_SYMBOL_IF_KUNIT(kasan_enable_hw_tags);
>
> -void kasan_force_async_fault(void)
> +VISIBLE_IF_KUNIT void kasan_force_async_fault(void)
>  {
>         hw_force_async_tag_fault();
>  }
> -EXPORT_SYMBOL_GPL(kasan_force_async_fault);
> +EXPORT_SYMBOL_IF_KUNIT(kasan_force_async_fault);
>
>  #endif
> diff --git a/mm/kasan/kasan_test_c.c b/mm/kasan/kasan_test_c.c
> index a181e4780d9d..3e495c09342e 100644
> --- a/mm/kasan/kasan_test_c.c
> +++ b/mm/kasan/kasan_test_c.c
> @@ -33,6 +33,8 @@
>
>  #define OOB_TAG_OFF (IS_ENABLED(CONFIG_KASAN_GENERIC) ? 0 : KASAN_GRANULE_SIZE)
>
> +MODULE_IMPORT_NS(EXPORTED_FOR_KUNIT_TESTING);
> +
>  static bool multishot;
>
>  /* Fields set based on lines observed in the console. */
> diff --git a/mm/kasan/report.c b/mm/kasan/report.c
> index b48c768acc84..e5bc4e3ee198 100644
> --- a/mm/kasan/report.c
> +++ b/mm/kasan/report.c
> @@ -10,6 +10,7 @@
>   */
>
>  #include <kunit/test.h>
> +#include <kunit/visibility.h>
>  #include <linux/bitops.h>
>  #include <linux/ftrace.h>
>  #include <linux/init.h>
> @@ -134,18 +135,18 @@ static bool report_enabled(void)
>
>  #if IS_ENABLED(CONFIG_KASAN_KUNIT_TEST) || IS_ENABLED(CONFIG_KASAN_MODULE_TEST)
>
> -bool kasan_save_enable_multi_shot(void)
> +VISIBLE_IF_KUNIT bool kasan_save_enable_multi_shot(void)
>  {
>         return test_and_set_bit(KASAN_BIT_MULTI_SHOT, &kasan_flags);
>  }
> -EXPORT_SYMBOL_GPL(kasan_save_enable_multi_shot);
> +EXPORT_SYMBOL_IF_KUNIT(kasan_save_enable_multi_shot);
>
> -void kasan_restore_multi_shot(bool enabled)
> +VISIBLE_IF_KUNIT void kasan_restore_multi_shot(bool enabled)
>  {
>         if (!enabled)
>                 clear_bit(KASAN_BIT_MULTI_SHOT, &kasan_flags);
>  }
> -EXPORT_SYMBOL_GPL(kasan_restore_multi_shot);
> +EXPORT_SYMBOL_IF_KUNIT(kasan_restore_multi_shot);
>
>  #endif
>
> @@ -157,17 +158,17 @@ EXPORT_SYMBOL_GPL(kasan_restore_multi_shot);
>   */
>  static bool kasan_kunit_executing;
>
> -void kasan_kunit_test_suite_start(void)
> +VISIBLE_IF_KUNIT void kasan_kunit_test_suite_start(void)
>  {
>         WRITE_ONCE(kasan_kunit_executing, true);
>  }
> -EXPORT_SYMBOL_GPL(kasan_kunit_test_suite_start);
> +EXPORT_SYMBOL_IF_KUNIT(kasan_kunit_test_suite_start);
>
> -void kasan_kunit_test_suite_end(void)
> +VISIBLE_IF_KUNIT void kasan_kunit_test_suite_end(void)
>  {
>         WRITE_ONCE(kasan_kunit_executing, false);
>  }
> -EXPORT_SYMBOL_GPL(kasan_kunit_test_suite_end);
> +EXPORT_SYMBOL_IF_KUNIT(kasan_kunit_test_suite_end);
>
>  static bool kasan_kunit_test_suite_executing(void)
>  {
> --
> 2.34.1
>

Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>

Thank you!

Re: [PATCH 2/2] kasan: change kasan_atomics kunit test as KUNIT_CASE_SLOW

[Andrey Konovalov]

On Fri, Nov 1, 2024 at 7:40 PM Sabyrzhan Tasbolatov <snovitoll@gmail.com> wrote:
>
> During running KASAN Kunit tests with CONFIG_KASAN enabled, the
> following "warning" is reported by kunit framework:
>
>         # kasan_atomics: Test should be marked slow (runtime: 2.604703115s)
>
> It took 2.6 seconds on my PC (Intel(R) Core(TM) i7-7700K CPU @ 4.20GHz),
> apparently, due to multiple atomic checks in kasan_atomics_helper().
>
> Let's mark it with KUNIT_CASE_SLOW which reports now as:
>
>         # kasan_atomics.speed: slow
>
> Signed-off-by: Sabyrzhan Tasbolatov <snovitoll@gmail.com>
> ---
>  mm/kasan/kasan_test_c.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/mm/kasan/kasan_test_c.c b/mm/kasan/kasan_test_c.c
> index 3e495c09342e..3946fc89a979 100644
> --- a/mm/kasan/kasan_test_c.c
> +++ b/mm/kasan/kasan_test_c.c
> @@ -2020,7 +2020,7 @@ static struct kunit_case kasan_kunit_test_cases[] = {
>         KUNIT_CASE(kasan_strings),
>         KUNIT_CASE(kasan_bitops_generic),
>         KUNIT_CASE(kasan_bitops_tags),
> -       KUNIT_CASE(kasan_atomics),
> +       KUNIT_CASE_SLOW(kasan_atomics),
>         KUNIT_CASE(vmalloc_helpers_tags),
>         KUNIT_CASE(vmalloc_oob),
>         KUNIT_CASE(vmap_tags),
> --
> 2.34.1
>

Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>