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

From: Andrey Konovalov
Date: Thu Oct 22 2020 - 09:20:30 EST


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@xxxxxxxxxx>
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