[PATCH v3 mm 04/13] kasan: clean up setting free info in kasan_slab_free

From: Andrey Konovalov <andreyknvl@google.com>
To: Andrew Morton <akpm@linux-foundation.org>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Vincenzo Frascino <vincenzo.frascino@arm.com>,
	Dmitry Vyukov <dvyukov@google.com>,
	Alexander Potapenko <glider@google.com>,
	Marco Elver <elver@google.com>
Cc: Will Deacon <will.deacon@arm.com>,
	Andrey Ryabinin <aryabinin@virtuozzo.com>,
	Peter Collingbourne <pcc@google.com>,
	Evgenii Stepanov <eugenis@google.com>,
	Branislav Rankov <Branislav.Rankov@arm.com>,
	Kevin Brodsky <kevin.brodsky@arm.com>,
	kasan-dev@googlegroups.com, linux-arm-kernel@lists.infradead.org,
	linux-mm@kvack.org, linux-kernel@vger.kernel.org,
	Andrey Konovalov <andreyknvl@google.com>
Subject: [PATCH v3 mm 04/13] kasan: clean up setting free info in kasan_slab_free
Date: Fri,  5 Feb 2021 18:34:38 +0100	[thread overview]
Message-ID: <f838e249be5ab5810bf54a36ef5072cfd80e2da7.1612546384.git.andreyknvl@google.com> (raw)
In-Reply-To: <cover.1612546384.git.andreyknvl@google.com>

Put kasan_stack_collection_enabled() check and kasan_set_free_info()
calls next to each other.

The way this was previously implemented was a minor optimization that
relied of the the fact that kasan_stack_collection_enabled() is always
true for generic KASAN. The confusion that this brings outweights saving
a few instructions.

Reviewed-by: Marco Elver <elver@google.com>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
---
 mm/kasan/common.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/mm/kasan/common.c b/mm/kasan/common.c
index f2a6bae13053..da24b144d46c 100644
--- a/mm/kasan/common.c
+++ b/mm/kasan/common.c
@@ -350,13 +350,11 @@ static bool ____kasan_slab_free(struct kmem_cache *cache, void *object,
 
 	kasan_poison(object, cache->object_size, KASAN_KMALLOC_FREE);
 
-	if (!kasan_stack_collection_enabled())
-		return false;
-
 	if ((IS_ENABLED(CONFIG_KASAN_GENERIC) && !quarantine))
 		return false;
 
-	kasan_set_free_info(cache, object, tag);
+	if (kasan_stack_collection_enabled())
+		kasan_set_free_info(cache, object, tag);
 
 	return kasan_quarantine_put(cache, object);
 }
-- 
2.30.0.365.g02bc693789-goog

