2 files changed, 25 insertions, 19 deletions

diff --git a/mm/kfence/Makefile b/mm/kfence/Makefile
index 0bb95728a784..2de2a58d11a1 100644
--- a/mm/kfence/Makefile
+++ b/mm/kfence/Makefile
@@ -2,5 +2,5 @@
 
 obj-y := core.o report.o
 
-CFLAGS_kfence_test.o := -g -fno-omit-frame-pointer -fno-optimize-sibling-calls
+CFLAGS_kfence_test.o := -fno-omit-frame-pointer -fno-optimize-sibling-calls
 obj-$(CONFIG_KFENCE_KUNIT_TEST) += kfence_test.o
diff --git a/mm/kfence/core.c b/mm/kfence/core.c
index 5abc79f16fe0..7d01a2c76e80 100644
--- a/mm/kfence/core.c
+++ b/mm/kfence/core.c
@@ -556,15 +556,11 @@ static unsigned long kfence_init_pool(void)
 	 * enters __slab_free() slow-path.
 	 */
 	for (i = 0; i < KFENCE_POOL_SIZE / PAGE_SIZE; i++) {
-		struct slab *slab = page_slab(&pages[i]);
+		struct slab *slab = page_slab(nth_page(pages, i));
 
 		if (!i || (i % 2))
 			continue;
 
-		/* Verify we do not have a compound head page. */
-		if (WARN_ON(compound_head(&pages[i]) != &pages[i]))
-			return addr;
-
 		__folio_set_slab(slab_folio(slab));
 #ifdef CONFIG_MEMCG
 		slab->memcg_data = (unsigned long)&kfence_metadata[i / 2 - 1].objcg |
@@ -597,12 +593,26 @@ static unsigned long kfence_init_pool(void)
 
 		/* Protect the right redzone. */
 		if (unlikely(!kfence_protect(addr + PAGE_SIZE)))
-			return addr;
+			goto reset_slab;
 
 		addr += 2 * PAGE_SIZE;
 	}
 
 	return 0;
+
+reset_slab:
+	for (i = 0; i < KFENCE_POOL_SIZE / PAGE_SIZE; i++) {
+		struct slab *slab = page_slab(nth_page(pages, i));
+
+		if (!i || (i % 2))
+			continue;
+#ifdef CONFIG_MEMCG
+		slab->memcg_data = 0;
+#endif
+		__folio_clear_slab(slab_folio(slab));
+	}
+
+	return addr;
 }
 
 static bool __init kfence_init_pool_early(void)
@@ -632,16 +642,6 @@ static bool __init kfence_init_pool_early(void)
 	 * fails for the first page, and therefore expect addr==__kfence_pool in
 	 * most failure cases.
 	 */
-	for (char *p = (char *)addr; p < __kfence_pool + KFENCE_POOL_SIZE; p += PAGE_SIZE) {
-		struct slab *slab = virt_to_slab(p);
-
-		if (!slab)
-			continue;
-#ifdef CONFIG_MEMCG
-		slab->memcg_data = 0;
-#endif
-		__folio_clear_slab(slab_folio(slab));
-	}
 	memblock_free_late(__pa(addr), KFENCE_POOL_SIZE - (addr - (unsigned long)__kfence_pool));
 	__kfence_pool = NULL;
 	return false;
@@ -726,10 +726,14 @@ static const struct seq_operations objects_sops = {
 };
 DEFINE_SEQ_ATTRIBUTE(objects);
 
-static int __init kfence_debugfs_init(void)
+static int kfence_debugfs_init(void)
 {
-	struct dentry *kfence_dir = debugfs_create_dir("kfence", NULL);
+	struct dentry *kfence_dir;
+
+	if (!READ_ONCE(kfence_enabled))
+		return 0;
 
+	kfence_dir = debugfs_create_dir("kfence", NULL);
 	debugfs_create_file("stats", 0444, kfence_dir, NULL, &stats_fops);
 	debugfs_create_file("objects", 0400, kfence_dir, NULL, &objects_fops);
 	return 0;
@@ -887,6 +891,8 @@ static int kfence_init_late(void)
 	}
 
 	kfence_init_enable();
+	kfence_debugfs_init();
+
 	return 0;
 }