Commit c8c7016f authored by Andrey Konovalov's avatar Andrey Konovalov Committed by Andrew Morton
Browse files

kasan: fail non-kasan KUnit tests on KASAN reports 

After the recent changes done to KUnit-enabled KASAN tests, non-KASAN
KUnit tests stopped being failed when KASAN report is detected.

Recover that property by failing the currently running non-KASAN KUnit
test when KASAN detects and prints a report for a bad memory access.

Note that if the bad accesses happened in a kernel thread that doesn't
have a reference to the currently running KUnit-test available via
current->kunit_test, the test won't be failed.  This is a limitation of
KUnit, which doesn't yet provide a thread-agnostic way to find the
reference to the currenly running test.

Link: https://lkml.kernel.org/r/7be29a8ea967cee6b7e48d3d5a242d1d0bd96851.1669820505.git.andreyknvl@google.com


Fixes: 49d9977a ("kasan: check CONFIG_KASAN_KUNIT_TEST instead of CONFIG_KUNIT")
Fixes: 7ce0ea19 ("kasan: switch kunit tests to console tracepoints")
Signed-off-by: default avatarAndrey Konovalov <andreyknvl@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: David Gow <davidgow@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Marco Elver <elver@google.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 19fc1a7e

mm/kasan/kasan.h

+12 −0
Original line number Diff line number Diff line
@@ -541,6 +541,18 @@ static inline bool kasan_arch_is_ready(void) { return true; } 
#error kasan_arch_is_ready only works in KASAN generic outline mode!

#endif



#if IS_ENABLED(CONFIG_KASAN_KUNIT_TEST)



void kasan_kunit_test_suite_start(void);

void kasan_kunit_test_suite_end(void);



#else /* CONFIG_KASAN_KUNIT_TEST */



static inline void kasan_kunit_test_suite_start(void) { }

static inline void kasan_kunit_test_suite_end(void) { }



#endif /* CONFIG_KASAN_KUNIT_TEST */



#if IS_ENABLED(CONFIG_KASAN_KUNIT_TEST) || IS_ENABLED(CONFIG_KASAN_MODULE_TEST)



bool kasan_save_enable_multi_shot(void);

mm/kasan/kasan_test.c

+4 −0
Original line number Diff line number Diff line
@@ -76,6 +76,9 @@ static int kasan_suite_init(struct kunit_suite *suite) 
		return -1;

	}



	/* Stop failing KUnit tests on KASAN reports. */

	kasan_kunit_test_suite_start();



	/*

	 * Temporarily enable multi-shot mode. Otherwise, KASAN would only

	 * report the first detected bug and panic the kernel if panic_on_warn
@@ -94,6 +97,7 @@ static int kasan_suite_init(struct kunit_suite *suite) 


static void kasan_suite_exit(struct kunit_suite *suite)

{

	kasan_kunit_test_suite_end();

	kasan_restore_multi_shot(multishot);

	for_each_kernel_tracepoint(unregister_tracepoints, NULL);

	tracepoint_synchronize_unregister();

mm/kasan/report.c

+53 −0
Original line number Diff line number Diff line
@@ -9,6 +9,7 @@ 
 *        Andrey Konovalov <andreyknvl@gmail.com>

 */



#include <kunit/test.h>

#include <linux/bitops.h>

#include <linux/ftrace.h>

#include <linux/init.h>
@@ -112,10 +113,62 @@ EXPORT_SYMBOL_GPL(kasan_restore_multi_shot); 


#endif



#if IS_ENABLED(CONFIG_KASAN_KUNIT_TEST)



/*

 * Whether the KASAN KUnit test suite is currently being executed.

 * Updated in kasan_test.c.

 */

bool kasan_kunit_executing;



void kasan_kunit_test_suite_start(void)

{

	WRITE_ONCE(kasan_kunit_executing, true);

}

EXPORT_SYMBOL_GPL(kasan_kunit_test_suite_start);



void kasan_kunit_test_suite_end(void)

{

	WRITE_ONCE(kasan_kunit_executing, false);

}

EXPORT_SYMBOL_GPL(kasan_kunit_test_suite_end);



static bool kasan_kunit_test_suite_executing(void)

{

	return READ_ONCE(kasan_kunit_executing);

}



#else /* CONFIG_KASAN_KUNIT_TEST */



static inline bool kasan_kunit_test_suite_executing(void) { return false; }



#endif /* CONFIG_KASAN_KUNIT_TEST */



#if IS_ENABLED(CONFIG_KUNIT)



static void fail_non_kasan_kunit_test(void)

{

	struct kunit *test;



	if (kasan_kunit_test_suite_executing())

		return;



	test = current->kunit_test;

	if (test)

		kunit_set_failure(test);

}



#else /* CONFIG_KUNIT */



static inline void fail_non_kasan_kunit_test(void) { }



#endif /* CONFIG_KUNIT */



static DEFINE_SPINLOCK(report_lock);



static void start_report(unsigned long *flags, bool sync)

{

	fail_non_kasan_kunit_test();

	/* Respect the /proc/sys/kernel/traceoff_on_warning interface. */

	disable_trace_on_warning();

	/* Do not allow LOCKDEP mangling KASAN reports. */