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smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=T5eBQYXJ; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="T5eBQYXJ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7543DC4CEC2; Wed, 4 Sep 2024 15:19:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1725463144; bh=4Chh2Trjq5PXaev8Wq994yU6ASdDaYO/5cXJBfvCKsU=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=T5eBQYXJngCBoEx6C7EPsk11Sq40ju6uc3HzdMFGqc1mPFsJiULiAJ3Y0DT8sW5Qu 4B6H0MTzcjpf/Smyed2MU7S7uB/FHysVHHW1ZMW2Wq3Zqt/lY2rVpklJ9P9sAJgPpT K3OnAn6KQeQnwuTGL8MqDu0Ot5neBtxoN52Jk9PUfjRAwzoj9lj4XlR9GPinYC4Hum UZzaOlzE3t4yBLviHQDZsiHB45ajDg86UrehJjYyVb27k8c3qEnQcqxBKo4QB5lbkk g+VKledzKUFdUcDhT5weErza6vVhVNzoez5ZVu4v6g3/UYuYpsMmaq3XQst3S5ntvB nzSd0euuHHy0g== Date: Wed, 4 Sep 2024 18:16:16 +0300 From: Mike Rapoport To: Christian Brauner Cc: Vlastimil Babka , Jens Axboe , Jann Horn , Linus Torvalds , linux-mm@kvack.org, linux-fsdevel@vger.kernel.org Subject: Re: [PATCH v2 02/15] slab: add struct kmem_cache_args Message-ID: References: <20240903-work-kmem_cache_args-v2-0-76f97e9a4560@kernel.org> <20240903-work-kmem_cache_args-v2-2-76f97e9a4560@kernel.org> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240903-work-kmem_cache_args-v2-2-76f97e9a4560@kernel.org> On Tue, Sep 03, 2024 at 04:20:43PM +0200, Christian Brauner wrote: > Signed-off-by: Christian Brauner > --- > include/linux/slab.h | 21 ++++++++++++++++ > mm/slab_common.c | 67 +++++++++++++++++++++++++++++++++++++++------------- > 2 files changed, 72 insertions(+), 16 deletions(-) > > diff --git a/include/linux/slab.h b/include/linux/slab.h > index 5b2da2cf31a8..79d8c8bca4a4 100644 > --- a/include/linux/slab.h > +++ b/include/linux/slab.h > @@ -240,6 +240,27 @@ struct mem_cgroup; > */ > bool slab_is_available(void); > > +/** > + * @align: The required alignment for the objects. > + * @useroffset: Usercopy region offset > + * @usersize: Usercopy region size > + * @freeptr_offset: Custom offset for the free pointer in RCU caches > + * @use_freeptr_offset: Whether a @freeptr_offset is used > + * @ctor: A constructor for the objects. > + */ > +struct kmem_cache_args { > + unsigned int align; > + unsigned int useroffset; > + unsigned int usersize; > + unsigned int freeptr_offset; > + bool use_freeptr_offset; > + void (*ctor)(void *); > +}; > + > +struct kmem_cache *__kmem_cache_create_args(const char *name, > + unsigned int object_size, > + struct kmem_cache_args *args, > + slab_flags_t flags); > struct kmem_cache *kmem_cache_create(const char *name, unsigned int size, > unsigned int align, slab_flags_t flags, > void (*ctor)(void *)); > diff --git a/mm/slab_common.c b/mm/slab_common.c > index 91e0e36e4379..0f13c045b8d1 100644 > --- a/mm/slab_common.c > +++ b/mm/slab_common.c > @@ -248,14 +248,24 @@ static struct kmem_cache *create_cache(const char *name, > return ERR_PTR(err); > } > > -static struct kmem_cache * > -do_kmem_cache_create_usercopy(const char *name, > - unsigned int size, unsigned int freeptr_offset, > - unsigned int align, slab_flags_t flags, > - unsigned int useroffset, unsigned int usersize, > - void (*ctor)(void *)) > +/** > + * __kmem_cache_create_args - Create a kmem cache > + * @name: A string which is used in /proc/slabinfo to identify this cache. > + * @object_size: The size of objects to be created in this cache. > + * @args: Arguments for the cache creation (see struct kmem_cache_args). > + * @flags: See %SLAB_* flags for an explanation of individual @flags. > + * > + * Cannot be called within a interrupt, but can be interrupted. > + * > + * Return: a pointer to the cache on success, NULL on failure. > + */ > +struct kmem_cache *__kmem_cache_create_args(const char *name, > + unsigned int object_size, > + struct kmem_cache_args *args, > + slab_flags_t flags) > { > struct kmem_cache *s = NULL; > + unsigned int freeptr_offset = UINT_MAX; > const char *cache_name; > int err; > > @@ -275,7 +285,7 @@ do_kmem_cache_create_usercopy(const char *name, > > mutex_lock(&slab_mutex); > > - err = kmem_cache_sanity_check(name, size); > + err = kmem_cache_sanity_check(name, object_size); > if (err) { > goto out_unlock; > } > @@ -296,12 +306,14 @@ do_kmem_cache_create_usercopy(const char *name, > > /* Fail closed on bad usersize of useroffset values. */ > if (!IS_ENABLED(CONFIG_HARDENED_USERCOPY) || > - WARN_ON(!usersize && useroffset) || > - WARN_ON(size < usersize || size - usersize < useroffset)) > - usersize = useroffset = 0; > - > - if (!usersize) > - s = __kmem_cache_alias(name, size, align, flags, ctor); > + WARN_ON(!args->usersize && args->useroffset) || > + WARN_ON(object_size < args->usersize || > + object_size - args->usersize < args->useroffset)) > + args->usersize = args->useroffset = 0; > + > + if (!args->usersize) > + s = __kmem_cache_alias(name, object_size, args->align, flags, > + args->ctor); Sorry I missed it in the previous review, but nothing guaranties that nobody will call kmem_cache_create_args with args != NULL. I think there should be a check for args != NULL and a substitution of args with defaults if it actually was NULL. > if (s) > goto out_unlock; > > @@ -311,9 +323,11 @@ do_kmem_cache_create_usercopy(const char *name, > goto out_unlock; > } > > - s = create_cache(cache_name, size, freeptr_offset, > - calculate_alignment(flags, align, size), > - flags, useroffset, usersize, ctor); > + if (args->use_freeptr_offset) > + freeptr_offset = args->freeptr_offset; > + s = create_cache(cache_name, object_size, freeptr_offset, > + calculate_alignment(flags, args->align, object_size), > + flags, args->useroffset, args->usersize, args->ctor); > if (IS_ERR(s)) { > err = PTR_ERR(s); > kfree_const(cache_name); > @@ -335,6 +349,27 @@ do_kmem_cache_create_usercopy(const char *name, > } > return s; > } > +EXPORT_SYMBOL(__kmem_cache_create_args); > + > +static struct kmem_cache * > +do_kmem_cache_create_usercopy(const char *name, > + unsigned int size, unsigned int freeptr_offset, > + unsigned int align, slab_flags_t flags, > + unsigned int useroffset, unsigned int usersize, > + void (*ctor)(void *)) > +{ > + struct kmem_cache_args kmem_args = { > + .align = align, > + .use_freeptr_offset = freeptr_offset != UINT_MAX, > + .freeptr_offset = freeptr_offset, > + .useroffset = useroffset, > + .usersize = usersize, > + .ctor = ctor, > + }; > + > + return __kmem_cache_create_args(name, size, &kmem_args, flags); > +} > + > > /** > * kmem_cache_create_usercopy - Create a cache with a region suitable > > -- > 2.45.2 > -- Sincerely yours, Mike.