Subject: [PATCH v5 2/5] slab: debug: split slab_kernel_map() to map and unmap variants

From: Mike Rapoport <[email-masked]>
Date: Sun, 8 Nov 2020 08:57:55 +0200

From: Mike Rapoport <[email-masked]>

Instead of using slab_kernel_map() with 'map' parameter to remap pages when
DEBUG_PAGEALLOC is enabled, use dedicated helpers slab_kernel_map() and
slab_kernel_unmap().

Signed-off-by: Mike Rapoport <[email-masked]>
---
 mm/slab.c | 26 +++++++++++++++-----------
 1 file changed, 15 insertions(+), 11 deletions(-)

diff --git a/mm/slab.c b/mm/slab.c
index 07317386e150..0719421d69f7 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -1428,17 +1428,21 @@ static bool is_debug_pagealloc_cache(struct kmem_cache *cachep)
 	return false;
 }
 
-static void slab_kernel_map(struct kmem_cache *cachep, void *objp, int map)
+static void slab_kernel_map(struct kmem_cache *cachep, void *objp)
 {
 	if (!is_debug_pagealloc_cache(cachep))
 		return;
 
-	if (map)
-		debug_pagealloc_map_pages(virt_to_page(objp),
-					  cachep->size / PAGE_SIZE);
-	else
-		debug_pagealloc_unmap_pages(virt_to_page(objp),
-					    cachep->size / PAGE_SIZE);
+	debug_pagealloc_map_pages(virt_to_page(objp), cachep->size / PAGE_SIZE);
+}
+
+static void slab_kernel_unmap(struct kmem_cache *cachep, void *objp)
+{
+	if (!is_debug_pagealloc_cache(cachep))
+		return;
+
+	debug_pagealloc_unmap_pages(virt_to_page(objp),
+				    cachep->size / PAGE_SIZE);
 }
 
 static void poison_obj(struct kmem_cache *cachep, void *addr, unsigned char val)
@@ -1585,7 +1589,7 @@ static void slab_destroy_debugcheck(struct kmem_cache *cachep,
 
 		if (cachep->flags & SLAB_POISON) {
 			check_poison_obj(cachep, objp);
-			slab_kernel_map(cachep, objp, 1);
+			slab_kernel_map(cachep, objp);
 		}
 		if (cachep->flags & SLAB_RED_ZONE) {
 			if (*dbg_redzone1(cachep, objp) != RED_INACTIVE)
@@ -2360,7 +2364,7 @@ static void cache_init_objs_debug(struct kmem_cache *cachep, struct page *page)
 		/* need to poison the objs? */
 		if (cachep->flags & SLAB_POISON) {
 			poison_obj(cachep, objp, POISON_FREE);
-			slab_kernel_map(cachep, objp, 0);
+			slab_kernel_unmap(cachep, objp);
 		}
 	}
 #endif
@@ -2728,7 +2732,7 @@ static void *cache_free_debugcheck(struct kmem_cache *cachep, void *objp,
 
 	if (cachep->flags & SLAB_POISON) {
 		poison_obj(cachep, objp, POISON_FREE);
-		slab_kernel_map(cachep, objp, 0);
+		slab_kernel_unmap(cachep, objp);
 	}
 	return objp;
 }
@@ -2993,7 +2997,7 @@ static void *cache_alloc_debugcheck_after(struct kmem_cache *cachep,
 		return objp;
 	if (cachep->flags & SLAB_POISON) {
 		check_poison_obj(cachep, objp);
-		slab_kernel_map(cachep, objp, 1);
+		slab_kernel_map(cachep, objp);
 		poison_obj(cachep, objp, POISON_INUSE);
 	}
 	if (cachep->flags & SLAB_STORE_USER)
-- 
2.28.0