Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965996AbaFTJjb (ORCPT ); Fri, 20 Jun 2014 05:39:31 -0400 Received: from cam-admin0.cambridge.arm.com ([217.140.96.50]:43734 "EHLO cam-admin0.cambridge.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964927AbaFTJja (ORCPT ); Fri, 20 Jun 2014 05:39:30 -0400 Date: Fri, 20 Jun 2014 10:38:56 +0100 From: Will Deacon To: Laura Abbott Cc: Catalin Marinas , David Riley , "linux-arm-kernel@lists.infradead.org" , Ritesh Harjain , "linux-mm@kvack.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCHv3 2/5] lib/genalloc.c: Add genpool range check function Message-ID: <20140620093856.GM25104@arm.com> References: <1402969165-7526-1-git-send-email-lauraa@codeaurora.org> <1402969165-7526-3-git-send-email-lauraa@codeaurora.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1402969165-7526-3-git-send-email-lauraa@codeaurora.org> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jun 17, 2014 at 02:39:22AM +0100, Laura Abbott wrote: > After allocating an address from a particular genpool, > there is no good way to verify if that address actually > belongs to a genpool. Introduce addr_in_gen_pool which > will return if an address plus size falls completely > within the genpool range. > > Signed-off-by: Laura Abbott > --- > include/linux/genalloc.h | 3 +++ > lib/genalloc.c | 29 +++++++++++++++++++++++++++++ > 2 files changed, 32 insertions(+) > > diff --git a/include/linux/genalloc.h b/include/linux/genalloc.h > index 3cd0934..1ccaab4 100644 > --- a/include/linux/genalloc.h > +++ b/include/linux/genalloc.h > @@ -121,6 +121,9 @@ extern struct gen_pool *devm_gen_pool_create(struct device *dev, > int min_alloc_order, int nid); > extern struct gen_pool *dev_get_gen_pool(struct device *dev); > > +bool addr_in_gen_pool(struct gen_pool *pool, unsigned long start, > + size_t size); > + > #ifdef CONFIG_OF > extern struct gen_pool *of_get_named_gen_pool(struct device_node *np, > const char *propname, int index); > diff --git a/lib/genalloc.c b/lib/genalloc.c > index 9758529..66edf93 100644 > --- a/lib/genalloc.c > +++ b/lib/genalloc.c > @@ -403,6 +403,35 @@ void gen_pool_for_each_chunk(struct gen_pool *pool, > EXPORT_SYMBOL(gen_pool_for_each_chunk); > > /** > + * addr_in_gen_pool - checks if an address falls within the range of a pool > + * @pool: the generic memory pool > + * @start: start address > + * @size: size of the region > + * > + * Check if the range of addresses falls within the specified pool. Takes > + * the rcu_read_lock for the duration of the check. > + */ > +bool addr_in_gen_pool(struct gen_pool *pool, unsigned long start, > + size_t size) > +{ > + bool found = false; > + unsigned long end = start + size; > + struct gen_pool_chunk *chunk; > + > + rcu_read_lock(); > + list_for_each_entry_rcu(chunk, &(pool)->chunks, next_chunk) { > + if (start >= chunk->start_addr && start <= chunk->end_addr) { Why do you need to check start against the end of the chunk? Is that in case of overflow? Will -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/