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From:   andrey.konovalov@linux.dev
To:     Andrew Morton <akpm@linux-foundation.org>
Cc:     Andrey Konovalov <andreyknvl@gmail.com>,
        Marco Elver <elver@google.com>,
        Alexander Potapenko <glider@google.com>,
        Dmitry Vyukov <dvyukov@google.com>,
        Andrey Ryabinin <ryabinin.a.a@gmail.com>,
        kasan-dev@googlegroups.com, linux-mm@kvack.org,
        Vincenzo Frascino <vincenzo.frascino@arm.com>,
        Catalin Marinas <catalin.marinas@arm.com>,
        Will Deacon <will@kernel.org>,
        Mark Rutland <mark.rutland@arm.com>,
        linux-arm-kernel@lists.infradead.org,
        Peter Collingbourne <pcc@google.com>,
        Evgenii Stepanov <eugenis@google.com>,
        linux-kernel@vger.kernel.org,
        Andrey Konovalov <andreyknvl@google.com>
Subject: [PATCH v6 04/39] kasan, page_alloc: simplify kasan_poison_pages call site
Date:   Mon, 24 Jan 2022 19:02:12 +0100
Message-Id: <ae4f9bcf071577258e786bcec4798c145d718c46.1643047180.git.andreyknvl@google.com>
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From: Andrey Konovalov <andreyknvl@google.com>

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 e5f95c6ab0ac..60bc838a4d85 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1302,6 +1302,7 @@ 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);
 
@@ -1374,19 +1375,10 @@ 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