[PATCH v2 2/2] slub: remove resiliency_test() function

From: glittao
Date: Tue Mar 30 2021 - 08:05:45 EST


From: Oliver Glitta <glittao@xxxxxxxxx>

Function resiliency_test() is hidden behind #ifdef
SLUB_RESILIENCY_TEST that is not part of Kconfig, so nobody
runs it.

This function is replaced with KUnit test for SLUB added
by the previous patch "selftests: add a KUnit test for SLUB
debugging functionality".

Signed-off-by: Oliver Glitta <glittao@xxxxxxxxx>

Acked-by: Vlastimil Babka <vbabka@xxxxxxx>
Acked-by: David Rientjes <rientjes@xxxxxxxxxx>
---
mm/slub.c | 64 -------------------------------------------------------
1 file changed, 64 deletions(-)

diff --git a/mm/slub.c b/mm/slub.c
index 06916e11a2bf..7270978c4e21 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -153,9 +153,6 @@ static inline bool kmem_cache_has_cpu_partial(struct kmem_cache *s)
* - Variable sizing of the per node arrays
*/

-/* Enable to test recovery from slab corruption on boot */
-#undef SLUB_RESILIENCY_TEST
-
/* Enable to log cmpxchg failures */
#undef SLUB_DEBUG_CMPXCHG

@@ -4923,66 +4920,6 @@ static int list_locations(struct kmem_cache *s, char *buf,
}
#endif /* CONFIG_SLUB_DEBUG */

-#ifdef SLUB_RESILIENCY_TEST
-static void __init resiliency_test(void)
-{
- u8 *p;
- int type = KMALLOC_NORMAL;
-
- BUILD_BUG_ON(KMALLOC_MIN_SIZE > 16 || KMALLOC_SHIFT_HIGH < 10);
-
- pr_err("SLUB resiliency testing\n");
- pr_err("-----------------------\n");
- pr_err("A. Corruption after allocation\n");
-
- p = kzalloc(16, GFP_KERNEL);
- p[16] = 0x12;
- pr_err("\n1. kmalloc-16: Clobber Redzone/next pointer 0x12->0x%p\n\n",
- p + 16);
-
- validate_slab_cache(kmalloc_caches[type][4]);
-
- /* Hmmm... The next two are dangerous */
- p = kzalloc(32, GFP_KERNEL);
- p[32 + sizeof(void *)] = 0x34;
- pr_err("\n2. kmalloc-32: Clobber next pointer/next slab 0x34 -> -0x%p\n",
- p);
- pr_err("If allocated object is overwritten then not detectable\n\n");
-
- validate_slab_cache(kmalloc_caches[type][5]);
- p = kzalloc(64, GFP_KERNEL);
- p += 64 + (get_cycles() & 0xff) * sizeof(void *);
- *p = 0x56;
- pr_err("\n3. kmalloc-64: corrupting random byte 0x56->0x%p\n",
- p);
- pr_err("If allocated object is overwritten then not detectable\n\n");
- validate_slab_cache(kmalloc_caches[type][6]);
-
- pr_err("\nB. Corruption after free\n");
- p = kzalloc(128, GFP_KERNEL);
- kfree(p);
- *p = 0x78;
- pr_err("1. kmalloc-128: Clobber first word 0x78->0x%p\n\n", p);
- validate_slab_cache(kmalloc_caches[type][7]);
-
- p = kzalloc(256, GFP_KERNEL);
- kfree(p);
- p[50] = 0x9a;
- pr_err("\n2. kmalloc-256: Clobber 50th byte 0x9a->0x%p\n\n", p);
- validate_slab_cache(kmalloc_caches[type][8]);
-
- p = kzalloc(512, GFP_KERNEL);
- kfree(p);
- p[512] = 0xab;
- pr_err("\n3. kmalloc-512: Clobber redzone 0xab->0x%p\n\n", p);
- validate_slab_cache(kmalloc_caches[type][9]);
-}
-#else
-#ifdef CONFIG_SYSFS
-static void resiliency_test(void) {};
-#endif
-#endif /* SLUB_RESILIENCY_TEST */
-
#ifdef CONFIG_SYSFS
enum slab_stat_type {
SL_ALL, /* All slabs */
@@ -5831,7 +5768,6 @@ static int __init slab_sysfs_init(void)
}

mutex_unlock(&slab_mutex);
- resiliency_test();
return 0;
}

--
2.17.1