Commit 83c4e7a0 authored by Patricia Alfonso's avatar Patricia Alfonso Committed by Linus Torvalds
Browse files

KUnit: KASAN Integration 

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@oracle.com/T/#t

)

Signed-off-by: default avatarPatricia Alfonso <trishalfonso@google.com>
Signed-off-by: default avatarDavid Gow <davidgow@google.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Tested-by: default avatarAndrey Konovalov <andreyknvl@google.com>
Reviewed-by: default avatarAndrey Konovalov <andreyknvl@google.com>
Reviewed-by: default avatarDmitry Vyukov <dvyukov@google.com>
Acked-by: default avatarBrendan Higgins <brendanhiggins@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Link: https://lkml.kernel.org/r/20200915035828.570483-3-davidgow@google.com
Link: https://lkml.kernel.org/r/20200910070331.3358048-3-davidgow@google.com


Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 393824f6

include/kunit/test.h

+5 −0
Original line number Diff line number Diff line
@@ -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);

include/linux/kasan.h

+6 −0
Original line number Diff line number Diff line
@@ -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];

lib/kunit/test.c

+8 −5
Original line number Diff line number Diff line
@@ -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);

lib/test_kasan.c

+45 −2
Original line number Diff line number Diff line
@@ -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;

mm/kasan/report.c

+32 −0
Original line number Diff line number Diff line
@@ -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;