Commit 8913c610 authored by Peng Liu's avatar Peng Liu Committed by Linus Torvalds
Browse files

kfence: make test case compatible with run time set sample interval 

The parameter kfence_sample_interval can be set via boot parameter and
late shell command, which is convenient for automated tests and KFENCE
parameter optimization.  However, KFENCE test case just uses
compile-time CONFIG_KFENCE_SAMPLE_INTERVAL, which will make KFENCE test
case not run as users desired.  Export kfence_sample_interval, so that
KFENCE test case can use run-time-set sample interval.

Link: https://lkml.kernel.org/r/20220207034432.185532-1-liupeng256@huawei.com


Signed-off-by: default avatarPeng Liu <liupeng256@huawei.com>
Reviewed-by: default avatarMarco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Christian Knig <christian.koenig@amd.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 0764db9b

include/linux/kfence.h

+2 −0
Original line number Diff line number Diff line
@@ -17,6 +17,8 @@ 
#include <linux/atomic.h>

#include <linux/static_key.h>



extern unsigned long kfence_sample_interval;



/*

 * We allocate an even number of pages, as it simplifies calculations to map

 * address to metadata indices; effectively, the very first page serves as an

mm/kfence/core.c

+2 −1
Original line number Diff line number Diff line
@@ -47,7 +47,8 @@ 


static bool kfence_enabled __read_mostly;



static unsigned long kfence_sample_interval __read_mostly = CONFIG_KFENCE_SAMPLE_INTERVAL;

unsigned long kfence_sample_interval __read_mostly = CONFIG_KFENCE_SAMPLE_INTERVAL;

EXPORT_SYMBOL_GPL(kfence_sample_interval); /* Export for test modules. */



#ifdef MODULE_PARAM_PREFIX

#undef MODULE_PARAM_PREFIX

mm/kfence/kfence_test.c

+4 −4
Original line number Diff line number Diff line
@@ -268,13 +268,13 @@ static void *test_alloc(struct kunit *test, size_t size, gfp_t gfp, enum allocat 
	 * 100x the sample interval should be more than enough to ensure we get

	 * a KFENCE allocation eventually.

	 */

	timeout = jiffies + msecs_to_jiffies(100 * CONFIG_KFENCE_SAMPLE_INTERVAL);

	timeout = jiffies + msecs_to_jiffies(100 * kfence_sample_interval);

	/*

	 * Especially for non-preemption kernels, ensure the allocation-gate

	 * timer can catch up: after @resched_after, every failed allocation

	 * attempt yields, to ensure the allocation-gate timer is scheduled.

	 */

	resched_after = jiffies + msecs_to_jiffies(CONFIG_KFENCE_SAMPLE_INTERVAL);

	resched_after = jiffies + msecs_to_jiffies(kfence_sample_interval);

	do {

		if (test_cache)

			alloc = kmem_cache_alloc(test_cache, gfp);
@@ -608,7 +608,7 @@ static void test_gfpzero(struct kunit *test) 
	int i;



	/* Skip if we think it'd take too long. */

	KFENCE_TEST_REQUIRES(test, CONFIG_KFENCE_SAMPLE_INTERVAL <= 100);

	KFENCE_TEST_REQUIRES(test, kfence_sample_interval <= 100);



	setup_test_cache(test, size, 0, NULL);

	buf1 = test_alloc(test, size, GFP_KERNEL, ALLOCATE_ANY);
@@ -739,7 +739,7 @@ static void test_memcache_alloc_bulk(struct kunit *test) 
	 * 100x the sample interval should be more than enough to ensure we get

	 * a KFENCE allocation eventually.

	 */

	timeout = jiffies + msecs_to_jiffies(100 * CONFIG_KFENCE_SAMPLE_INTERVAL);

	timeout = jiffies + msecs_to_jiffies(100 * kfence_sample_interval);

	do {

		void *objects[100];

		int i, num = kmem_cache_alloc_bulk(test_cache, GFP_ATOMIC, ARRAY_SIZE(objects),