kfence, slab: fix cache_alloc_debugcheck_after() for bulk allocations

cache_alloc_debugcheck_after() performs checks on an object, including
adjusting the returned pointer. None of this should apply to KFENCE
objects. While for non-bulk allocations, the checks are skipped when we
allocate via KFENCE, for bulk allocations cache_alloc_debugcheck_after()
is called via cache_alloc_debugcheck_after_bulk().

Fix it by skipping cache_alloc_debugcheck_after() for KFENCE objects.

Signed-off-by: Marco Elver <elver@google.com>
[port kfence feature to rpi-5.10.95]
Signed-off-by: Sung-hun Kim <sfoon.kim@samsung.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Seung-Woo Kim <sw0312.kim@samsung.com>
Change-Id: I07e1131fb1659455be3ac7e65147e627de63520a

diff --git a/mm/slab.c b/mm/slab.c
index 88e54dd..f107c46 100644 (file)
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -2991,7 +2991,7 @@ static void *cache_alloc_debugcheck_after(struct kmem_cache *cachep,
                                gfp_t flags, void *objp, unsigned long caller)
 {
        WARN_ON_ONCE(cachep->ctor && (flags & __GFP_ZERO));
-       if (!objp)
+       if (!objp || is_kfence_address(objp))
                return objp;
        if (cachep->flags & SLAB_POISON) {
                check_poison_obj(cachep, objp);