diff mbox series

[mm,v3,11/38] kasan, page_alloc: combine tag_clear_highpage calls in post_alloc_hook

Message ID 585c27bfa692331cd75de7c9dc713a318d3db466.1639432170.git.andreyknvl@google.com (mailing list archive)
State New, archived
Headers show
Series kasan, vmalloc, arm64: add vmalloc tagging support for SW/HW_TAGS | expand

Commit Message

andrey.konovalov@linux.dev Dec. 13, 2021, 9:53 p.m. UTC 
From: Andrey Konovalov <andreyknvl@google.com>

Move tag_clear_highpage() loops out of the kasan_has_integrated_init()
clause as a code simplification.

This patch does no functional changes.

Signed-off-by: Andrey Konovalov <andreyknvl@google.com>

---

Changes v2->v3:
- Update patch description.
---
 mm/page_alloc.c | 32 ++++++++++++++++----------------
 1 file changed, 16 insertions(+), 16 deletions(-)

Comments

Alexander Potapenko Dec. 16, 2021, 1:04 p.m. UTC | #1 
On Mon, Dec 13, 2021 at 10:53 PM <andrey.konovalov@linux.dev> wrote:
>
> From: Andrey Konovalov <andreyknvl@google.com>
>
> Move tag_clear_highpage() loops out of the kasan_has_integrated_init()
> clause as a code simplification.
>
> This patch does no functional changes.
>
> Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
diff mbox series

Patch

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index a2e32a8abd7f..2d1e63a01ed8 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -2418,30 +2418,30 @@  inline void post_alloc_hook(struct page *page, unsigned int order,
 	 * KASAN unpoisoning and memory initializion code must be
 	 * kept together to avoid discrepancies in behavior.
 	 */
+
+	/*
+	 * If memory tags should be zeroed (which happens only when memory
+	 * should be initialized as well).
+	 */
+	if (init_tags) {
+		int i;
+
+		/* Initialize both memory and tags. */
+		for (i = 0; i != 1 << order; ++i)
+			tag_clear_highpage(page + i);
+
+		/* Note that memory is already initialized by the loop above. */
+		init = false;
+	}
 	if (kasan_has_integrated_init()) {
 		if (gfp_flags & __GFP_SKIP_KASAN_POISON)
 			SetPageSkipKASanPoison(page);
 
-		if (init_tags) {
-			int i;
-
-			for (i = 0; i != 1 << order; ++i)
-				tag_clear_highpage(page + i);
-		} else {
+		if (!init_tags)
 			kasan_unpoison_pages(page, order, init);
-		}
 	} else {
 		kasan_unpoison_pages(page, order, init);
 
-		if (init_tags) {
-			int i;
-
-			for (i = 0; i < 1 << order; i++)
-				tag_clear_highpage(page + i);
-
-			init = false;
-		}
-
 		if (init)
 			kernel_init_free_pages(page, 1 << order);
 	}