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DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1662412148; 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=Oe1I5rgVNwQpGV6INl9iERGx4SyKKLbT68poGoo1Dv4=; b=PL+hF7kcBhca/C4p85FTUxrzhI/jk7IqFqEgnbp+mNCuejb3QovS4fDjFZxPFMvXxsDzwF g0l2igLCasWBjG8OFV/mbVfQMjnHBprq0kdFmrgZ8bykcDoB9fBsI4LLIDOHt6ufDiS5Xn hfAcmnNKK8mT/DRfcNyM2+Wxf5EXGyk= From: andrey.konovalov@linux.dev To: Andrew Morton Cc: Andrey Konovalov , Marco Elver , Alexander Potapenko , Dmitry Vyukov , Andrey Ryabinin , kasan-dev@googlegroups.com, Peter Collingbourne , Evgenii Stepanov , Florian Mayer , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Andrey Konovalov Subject: [PATCH mm v3 18/34] kasan: only define kasan_cache_create for Generic mode Date: Mon, 5 Sep 2022 23:05:33 +0200 Message-Id: <61faa2aa1906e2d02c97d00ddf99ce8911dda095.1662411799.git.andreyknvl@google.com> In-Reply-To: References: MIME-Version: 1.0 X-Migadu-Flow: FLOW_OUT X-Migadu-Auth-User: linux.dev ARC-Authentication-Results: i=1; imf12.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=PL+hF7kc; spf=pass (imf12.hostedemail.com: domain of andrey.konovalov@linux.dev designates 94.23.1.103 as permitted sender) smtp.mailfrom=andrey.konovalov@linux.dev; dmarc=pass (policy=none) header.from=linux.dev ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1662412149; a=rsa-sha256; cv=none; b=vgUtZYwC7fnADDml+F/GofTuE3iSVGaQFBeUL4cREJszKduaRY1lmV/nq5JcXxmIiciU0j C+6EntDkJtyCLyjjXllOsAUaZZtsWXaYZfVzFp4zt1iRTKD9E9PLIZ6dBSOItvD/nHZo4t zGwzimisashho2EbAoX+1Vt5uvoLO+E= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1662412149; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=Oe1I5rgVNwQpGV6INl9iERGx4SyKKLbT68poGoo1Dv4=; b=e+O2TwI4Wi70eP/a3D2kVshO5d7ucrgJ8Hwg2yxwPrt14IalngyetBgv3leO1AMkOkk0qH xtu0ZULXhDTWe4AbL1BHyoUdk6dsgPzY/BH/kcGs74VsvmKDssp9Sarn4uTTSR3f6AlmeG JuY/uGeOuqUmEDeCOYbW6wPeJ8Z7NVE= Authentication-Results: imf12.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=PL+hF7kc; spf=pass (imf12.hostedemail.com: domain of andrey.konovalov@linux.dev designates 94.23.1.103 as permitted sender) smtp.mailfrom=andrey.konovalov@linux.dev; dmarc=pass (policy=none) header.from=linux.dev X-Rspam-User: X-Stat-Signature: zb1ddwyrztryw1wk8q3masa4841hnw58 X-Rspamd-Queue-Id: BC1964007D X-Rspamd-Server: rspam05 X-HE-Tag: 1662412149-753512 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: From: Andrey Konovalov Right now, kasan_cache_create() assigns SLAB_KASAN for all KASAN modes and then sets up metadata-related cache parameters for the Generic mode. SLAB_KASAN is used in two places: 1. In slab_ksize() to account for per-object metadata when calculating the size of the accessible memory within the object. 2. In slab_common.c via kasan_never_merge() to prevent merging of caches with per-object metadata. Both cases are only relevant when per-object metadata is present, which is only the case with the Generic mode. Thus, assign SLAB_KASAN and define kasan_cache_create() only for the Generic mode. Also update the SLAB_KASAN-related comment. Reviewed-by: Marco Elver Signed-off-by: Andrey Konovalov --- include/linux/kasan.h | 18 ++++++------------ include/linux/slab.h | 2 +- mm/kasan/common.c | 16 ---------------- mm/kasan/generic.c | 17 ++++++++++++++++- 4 files changed, 23 insertions(+), 30 deletions(-) diff --git a/include/linux/kasan.h b/include/linux/kasan.h index a212c2e3f32d..d811b3d7d2a1 100644 --- a/include/linux/kasan.h +++ b/include/linux/kasan.h @@ -128,15 +128,6 @@ static __always_inline void kasan_unpoison_pages(struct page *page, __kasan_unpoison_pages(page, order, init); } -void __kasan_cache_create(struct kmem_cache *cache, unsigned int *size, - slab_flags_t *flags); -static __always_inline void kasan_cache_create(struct kmem_cache *cache, - unsigned int *size, slab_flags_t *flags) -{ - if (kasan_enabled()) - __kasan_cache_create(cache, size, flags); -} - void __kasan_cache_create_kmalloc(struct kmem_cache *cache); static __always_inline void kasan_cache_create_kmalloc(struct kmem_cache *cache) { @@ -260,9 +251,6 @@ static inline void kasan_poison_pages(struct page *page, unsigned int order, bool init) {} static inline void kasan_unpoison_pages(struct page *page, unsigned int order, bool init) {} -static inline void kasan_cache_create(struct kmem_cache *cache, - unsigned int *size, - slab_flags_t *flags) {} static inline void kasan_cache_create_kmalloc(struct kmem_cache *cache) {} static inline void kasan_poison_slab(struct slab *slab) {} static inline void kasan_unpoison_object_data(struct kmem_cache *cache, @@ -316,6 +304,8 @@ static inline void kasan_unpoison_task_stack(struct task_struct *task) {} size_t kasan_metadata_size(struct kmem_cache *cache); slab_flags_t kasan_never_merge(void); +void kasan_cache_create(struct kmem_cache *cache, unsigned int *size, + slab_flags_t *flags); void kasan_cache_shrink(struct kmem_cache *cache); void kasan_cache_shutdown(struct kmem_cache *cache); @@ -334,6 +324,10 @@ static inline slab_flags_t kasan_never_merge(void) { return 0; } +/* And no cache-related metadata initialization is required. */ +static inline void kasan_cache_create(struct kmem_cache *cache, + unsigned int *size, + slab_flags_t *flags) {} static inline void kasan_cache_shrink(struct kmem_cache *cache) {} static inline void kasan_cache_shutdown(struct kmem_cache *cache) {} diff --git a/include/linux/slab.h b/include/linux/slab.h index 0fefdf528e0d..1c6b7362e82b 100644 --- a/include/linux/slab.h +++ b/include/linux/slab.h @@ -106,7 +106,7 @@ # define SLAB_ACCOUNT 0 #endif -#ifdef CONFIG_KASAN +#ifdef CONFIG_KASAN_GENERIC #define SLAB_KASAN ((slab_flags_t __force)0x08000000U) #else #define SLAB_KASAN 0 diff --git a/mm/kasan/common.c b/mm/kasan/common.c index c2690e938030..8efa63190951 100644 --- a/mm/kasan/common.c +++ b/mm/kasan/common.c @@ -110,22 +110,6 @@ void __kasan_poison_pages(struct page *page, unsigned int order, bool init) KASAN_PAGE_FREE, init); } -void __kasan_cache_create(struct kmem_cache *cache, unsigned int *size, - slab_flags_t *flags) -{ - /* - * SLAB_KASAN is used to mark caches as ones that are sanitized by - * KASAN. Currently this flag is used in two places: - * 1. In slab_ksize() when calculating the size of the accessible - * memory within the object. - * 2. In slab_common.c to prevent merging of sanitized caches. - */ - *flags |= SLAB_KASAN; - - if (kasan_requires_meta()) - kasan_init_cache_meta(cache, size); -} - void __kasan_cache_create_kmalloc(struct kmem_cache *cache) { cache->kasan_info.is_kmalloc = true; diff --git a/mm/kasan/generic.c b/mm/kasan/generic.c index 25333bf3c99f..f6bef347de87 100644 --- a/mm/kasan/generic.c +++ b/mm/kasan/generic.c @@ -352,11 +352,26 @@ static inline unsigned int optimal_redzone(unsigned int object_size) object_size <= (1 << 16) - 1024 ? 1024 : 2048; } -void kasan_init_cache_meta(struct kmem_cache *cache, unsigned int *size) +void kasan_cache_create(struct kmem_cache *cache, unsigned int *size, + slab_flags_t *flags) { unsigned int ok_size; unsigned int optimal_size; + if (!kasan_requires_meta()) + return; + + /* + * SLAB_KASAN is used to mark caches that are sanitized by KASAN + * and that thus have per-object metadata. + * Currently this flag is used in two places: + * 1. In slab_ksize() to account for per-object metadata when + * calculating the size of the accessible memory within the object. + * 2. In slab_common.c via kasan_never_merge() to prevent merging of + * caches with per-object metadata. + */ + *flags |= SLAB_KASAN; + ok_size = *size; /* Add alloc meta into redzone. */