From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pd0-f169.google.com (mail-pd0-f169.google.com [209.85.192.169]) by kanga.kvack.org (Postfix) with ESMTP id ED0386B0036 for ; Sun, 29 Jun 2014 15:38:12 -0400 (EDT) Received: by mail-pd0-f169.google.com with SMTP id g10so7022621pdj.14 for ; Sun, 29 Jun 2014 12:38:12 -0700 (PDT) Received: from smtp.codeaurora.org (smtp.codeaurora.org. [198.145.11.231]) by mx.google.com with ESMTPS id ka6si20654068pbc.153.2014.06.29.12.38.11 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sun, 29 Jun 2014 12:38:12 -0700 (PDT) Message-ID: <53B06B22.9090203@codeaurora.org> Date: Sun, 29 Jun 2014 12:38:10 -0700 From: Laura Abbott MIME-Version: 1.0 Subject: Re: [PATCHv3 2/5] lib/genalloc.c: Add genpool range check function References: <1402969165-7526-1-git-send-email-lauraa@codeaurora.org> <1402969165-7526-3-git-send-email-lauraa@codeaurora.org> <20140620093856.GM25104@arm.com> In-Reply-To: <20140620093856.GM25104@arm.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Will Deacon Cc: David Riley , Catalin Marinas , "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" , Ritesh Harjain , "linux-arm-kernel@lists.infradead.org" On 6/20/2014 2:38 AM, Will Deacon wrote: > 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? > Yes, this provides an extra check for overflow and also matches similar logic for gen_pool_virt_to_phys. Thanks, Laura -- Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org