From nobody Fri Dec 19 14:25:59 2025 Received: from out-184.mta0.migadu.com (out-184.mta0.migadu.com [91.218.175.184]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C009F3D0DB for ; Tue, 19 Dec 2023 22:30:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="Ctrg2ZB1" X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1703025020; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=TOZdtH5KljVO+QBwvb475Ri4NSt7i5y2rX8Y2gdn2wY=; b=Ctrg2ZB1vr09mQJDl/g4xpRjwYVqozqH5I/yyeUDJ9kKUUsjofuMXHKU5XEuSmxPXCR5w9 dDaoAQH0Z6U4wMeGi6PrDUTFdO+Rj/pE+kqT96iJ8qj/ZdT+fG6UmURjrqCkw90n3UvUpY cDiRSDo85Tluc4i4aNZ0g57lX0tLRX8= From: andrey.konovalov@linux.dev To: Marco Elver , Alexander Potapenko Cc: Andrey Konovalov , Dmitry Vyukov , Andrey Ryabinin , kasan-dev@googlegroups.com, Evgenii Stepanov , Breno Leitao , Alexander Lobakin , Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Andrey Konovalov Subject: [PATCH mm 10/21] kasan: clean up and rename ____kasan_kmalloc Date: Tue, 19 Dec 2023 23:28:54 +0100 Message-Id: <5881232ad357ec0d59a5b1aefd9e0673a386399a.1703024586.git.andreyknvl@google.com> In-Reply-To: References: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Migadu-Flow: FLOW_OUT Content-Type: text/plain; charset="utf-8" From: Andrey Konovalov Introduce a new poison_kmalloc_redzone helper function that poisons the redzone for kmalloc object. Drop the confusingly named ____kasan_kmalloc function and instead use poison_kmalloc_redzone along with the other required parts of ____kasan_kmalloc in the callers' code. This is a preparatory change for the following patches in this series. Signed-off-by: Andrey Konovalov --- mm/kasan/common.c | 42 ++++++++++++++++++++++-------------------- 1 file changed, 22 insertions(+), 20 deletions(-) diff --git a/mm/kasan/common.c b/mm/kasan/common.c index 59146886e57d..1217b260abc3 100644 --- a/mm/kasan/common.c +++ b/mm/kasan/common.c @@ -312,26 +312,12 @@ void * __must_check __kasan_slab_alloc(struct kmem_ca= che *cache, return tagged_object; } =20 -static inline void *____kasan_kmalloc(struct kmem_cache *cache, +static inline void poison_kmalloc_redzone(struct kmem_cache *cache, const void *object, size_t size, gfp_t flags) { unsigned long redzone_start; unsigned long redzone_end; =20 - if (gfpflags_allow_blocking(flags)) - kasan_quarantine_reduce(); - - if (unlikely(object =3D=3D NULL)) - return NULL; - - if (is_kfence_address(kasan_reset_tag(object))) - return (void *)object; - - /* - * The object has already been unpoisoned by kasan_slab_alloc() for - * kmalloc() or by kasan_krealloc() for krealloc(). - */ - /* * The redzone has byte-level precision for the generic mode. * Partially poison the last object granule to cover the unaligned @@ -355,14 +341,25 @@ static inline void *____kasan_kmalloc(struct kmem_cac= he *cache, if (kasan_stack_collection_enabled() && is_kmalloc_cache(cache)) kasan_save_alloc_info(cache, (void *)object, flags); =20 - /* Keep the tag that was set by kasan_slab_alloc(). */ - return (void *)object; } =20 void * __must_check __kasan_kmalloc(struct kmem_cache *cache, const void *= object, size_t size, gfp_t flags) { - return ____kasan_kmalloc(cache, object, size, flags); + if (gfpflags_allow_blocking(flags)) + kasan_quarantine_reduce(); + + if (unlikely(object =3D=3D NULL)) + return NULL; + + if (is_kfence_address(kasan_reset_tag(object))) + return (void *)object; + + /* The object has already been unpoisoned by kasan_slab_alloc(). */ + poison_kmalloc_redzone(cache, object, size, flags); + + /* Keep the tag that was set by kasan_slab_alloc(). */ + return (void *)object; } EXPORT_SYMBOL(__kasan_kmalloc); =20 @@ -408,6 +405,9 @@ void * __must_check __kasan_krealloc(const void *object= , size_t size, gfp_t flag if (unlikely(object =3D=3D ZERO_SIZE_PTR)) return (void *)object; =20 + if (is_kfence_address(kasan_reset_tag(object))) + return (void *)object; + /* * Unpoison the object's data. * Part of it might already have been unpoisoned, but it's unknown @@ -420,8 +420,10 @@ void * __must_check __kasan_krealloc(const void *objec= t, size_t size, gfp_t flag /* Piggy-back on kmalloc() instrumentation to poison the redzone. */ if (unlikely(!slab)) return __kasan_kmalloc_large(object, size, flags); - else - return ____kasan_kmalloc(slab->slab_cache, object, size, flags); + else { + poison_kmalloc_redzone(slab->slab_cache, object, size, flags); + return (void *)object; + } } =20 bool __kasan_mempool_poison_pages(struct page *page, unsigned int order, --=20 2.25.1