slub: remove resiliency_test() function

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".

Link: https://lkml.kernel.org/r/20210511150734.3492-3-glittao@gmail.com
Signed-off-by: Oliver Glitta <glittao@gmail.com>
Reviewed-by: Marco Elver <elver@google.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Oliver Glitta <glittao@gmail.com>
Cc: Brendan Higgins <brendanhiggins@google.com>
Cc: Daniel Latypov <dlatypov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/slub.c

@@ -155,9 +155,6 @@ 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
 
@@ -4938,66 +4935,6 @@ 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 */
@@ -5846,7 +5783,6 @@ static int __init slab_sysfs_init(void)
 	}
 
 	mutex_unlock(&slab_mutex);
-	resiliency_test();
 	return 0;
 }