From nobody Fri Dec 19 14:10:56 2025 Received: from out-180.mta0.migadu.com (out-180.mta0.migadu.com [91.218.175.180]) (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 A54F13D0D5 for ; Tue, 19 Dec 2023 22:30:23 +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="SkAJqCw+" 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=1703025021; 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=+EoZxIVuEAKv7x5FH4zs492QikDHeQQIvGcyYCPoQRk=; b=SkAJqCw+CpgpYcxkKbpNsgiVRs3jZsJLDCK6h/+n2tye0d1nsMHpkQEKaGwzu+Y3ortVD6 2V4tHBKknFNLP7uf44CoMBA1yfnNNq11AYTUObnX7PBrHpXsVtYRLuuPg5ub4gL7k2ldkm fH/a/eow85Q+6vMR0kRodOwNov6scpA= 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 11/21] kasan: introduce poison_kmalloc_large_redzone Date: Tue, 19 Dec 2023 23:28:55 +0100 Message-Id: <93317097b668519d76097fb065201b2027436e22.1703024586.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 Split out a poison_kmalloc_large_redzone helper from __kasan_kmalloc_large and use it in the caller's code. This is a preparatory change for the following patches in this series. Signed-off-by: Andrey Konovalov --- mm/kasan/common.c | 41 +++++++++++++++++++++++------------------ 1 file changed, 23 insertions(+), 18 deletions(-) diff --git a/mm/kasan/common.c b/mm/kasan/common.c index 1217b260abc3..962805bf5f62 100644 --- a/mm/kasan/common.c +++ b/mm/kasan/common.c @@ -363,23 +363,12 @@ void * __must_check __kasan_kmalloc(struct kmem_cache= *cache, const void *object } EXPORT_SYMBOL(__kasan_kmalloc); =20 -void * __must_check __kasan_kmalloc_large(const void *ptr, size_t size, +static inline void poison_kmalloc_large_redzone(const void *ptr, size_t si= ze, gfp_t flags) { unsigned long redzone_start; unsigned long redzone_end; =20 - if (gfpflags_allow_blocking(flags)) - kasan_quarantine_reduce(); - - if (unlikely(ptr =3D=3D NULL)) - return NULL; - - /* - * The object has already been unpoisoned by kasan_unpoison_pages() for - * alloc_pages() 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 @@ -389,12 +378,25 @@ void * __must_check __kasan_kmalloc_large(const void = *ptr, size_t size, kasan_poison_last_granule(ptr, size); =20 /* Poison the aligned part of the redzone. */ - redzone_start =3D round_up((unsigned long)(ptr + size), - KASAN_GRANULE_SIZE); + redzone_start =3D round_up((unsigned long)(ptr + size), KASAN_GRANULE_SIZ= E); redzone_end =3D (unsigned long)ptr + page_size(virt_to_page(ptr)); kasan_poison((void *)redzone_start, redzone_end - redzone_start, KASAN_PAGE_REDZONE, false); +} =20 +void * __must_check __kasan_kmalloc_large(const void *ptr, size_t size, + gfp_t flags) +{ + if (gfpflags_allow_blocking(flags)) + kasan_quarantine_reduce(); + + if (unlikely(ptr =3D=3D NULL)) + return NULL; + + /* The object has already been unpoisoned by kasan_unpoison_pages(). */ + poison_kmalloc_large_redzone(ptr, size, flags); + + /* Keep the tag that was set by alloc_pages(). */ return (void *)ptr; } =20 @@ -402,6 +404,9 @@ void * __must_check __kasan_krealloc(const void *object= , size_t size, gfp_t flag { struct slab *slab; =20 + if (gfpflags_allow_blocking(flags)) + kasan_quarantine_reduce(); + if (unlikely(object =3D=3D ZERO_SIZE_PTR)) return (void *)object; =20 @@ -419,11 +424,11 @@ void * __must_check __kasan_krealloc(const void *obje= ct, size_t size, gfp_t flag =20 /* Piggy-back on kmalloc() instrumentation to poison the redzone. */ if (unlikely(!slab)) - return __kasan_kmalloc_large(object, size, flags); - else { + poison_kmalloc_large_redzone(object, size, flags); + else poison_kmalloc_redzone(slab->slab_cache, object, size, flags); - return (void *)object; - } + + return (void *)object; } =20 bool __kasan_mempool_poison_pages(struct page *page, unsigned int order, --=20 2.25.1