[PATCH RFC v2 17/21] kasan: simplify kasan_poison_kfree

[Andrey Konovalov]

kasan_poison_kfree() is currently only called for mempool allocations
that are backed by either kmem_cache_alloc() or kmalloc(). Therefore, the
page passed to kasan_poison_kfree() is always PageSlab() and there's no
need to do the check.

Signed-off-by: Andrey Konovalov <andreyknvl at google.com>
Link: https://linux-review.googlesource.com/id/If31f88726745da8744c6bea96fb32584e6c2778c
---
 mm/kasan/common.c | 11 +----------
 1 file changed, 1 insertion(+), 10 deletions(-)

diff --git a/mm/kasan/common.c b/mm/kasan/common.c
index a581937c2a44..b82dbae0c5d6 100644
--- a/mm/kasan/common.c
+++ b/mm/kasan/common.c
@@ -441,16 +441,7 @@ void __kasan_poison_kfree(void *ptr, unsigned long ip)
 	struct page *page;
 
 	page = virt_to_head_page(ptr);
-
-	if (unlikely(!PageSlab(page))) {
-		if (ptr != page_address(page)) {
-			kasan_report_invalid_free(ptr, ip);
-			return;
-		}
-		kasan_poison_memory(ptr, page_size(page), KASAN_FREE_PAGE);
-	} else {
-		____kasan_slab_free(page->slab_cache, ptr, ip, false);
-	}
+	____kasan_slab_free(page->slab_cache, ptr, ip, false);
 }
 
 void __kasan_kfree_large(void *ptr, unsigned long ip)
-- 
2.29.0.rc1.297.gfa9743e501-goog