[PATCH mm v4 04/39] kasan, page_alloc: simplify kasan_poison_pages call site

andrey.konovalov
2021-12-20T21:59:09Z

Simplify the code around calling kasan_poison_pages() in
free_pages_prepare().

This patch does no functional changes.

Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Alexander Potapenko <glider@google.com>

---

Changes v1->v2:
- Don't reorder kasan_poison_pages() and free_pages_prepare().
---
mm/page_alloc.c | 18 +++++-------------
1 file changed, 5 insertions(+), 13 deletions(-)

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 740fb01a27ed..db8cecdd0aaa 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1301,6 +1301,7 @@ static __always_inline bool free_pages_prepare(struct page *page,
{
int bad = 0;
bool skip_kasan_poison = should_skip_kasan_poison(page, fpi_flags);
+ bool init = want_init_on_free();

VM_BUG_ON_PAGE(PageTail(page), page);

@@ -1373,19 +1374,10 @@ static __always_inline bool free_pages_prepare(struct page *page,
* With hardware tag-based KASAN, memory tags must be set before the
* page becomes unavailable via debug_pagealloc or arch_free_page.
*/
- if (kasan_has_integrated_init()) {
- bool init = want_init_on_free();
-
- if (!skip_kasan_poison)
- kasan_poison_pages(page, order, init);
- } else {
- bool init = want_init_on_free();
-
- if (init)
- kernel_init_free_pages(page, 1 << order);
- if (!skip_kasan_poison)
- kasan_poison_pages(page, order, init);
- }
+ if (init && !kasan_has_integrated_init())
+ kernel_init_free_pages(page, 1 << order);
+ if (!skip_kasan_poison)
+ kasan_poison_pages(page, order, init);

/*
* arch_free_page() can make the page's contents inaccessible. s390
--
2.25.1