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

From: Mike Rapoport
Date: Sun Nov 08 2020 - 01:58:46 EST


From: Mike Rapoport <rppt@xxxxxxxxxxxxx>

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 <rppt@xxxxxxxxxxxxx>
---
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