Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752661AbcCAJnZ (ORCPT ); Tue, 1 Mar 2016 04:43:25 -0500 Received: from mail-wm0-f45.google.com ([74.125.82.45]:34906 "EHLO mail-wm0-f45.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751881AbcCAJnV (ORCPT ); Tue, 1 Mar 2016 04:43:21 -0500 Subject: Re: [PATCH v2] irqchip/gicv3-its: Don't allow devices whose ID is outside range To: Shanker Donthineni , Marc Zyngier , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org References: <1456687323-8446-1-git-send-email-shankerd@codeaurora.org> Cc: Thomas Gleixner , Jason Cooper , Vikram Sethi From: Eric Auger Message-ID: <56D56411.1070002@linaro.org> Date: Tue, 1 Mar 2016 10:42:41 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.5.1 MIME-Version: 1.0 In-Reply-To: <1456687323-8446-1-git-send-email-shankerd@codeaurora.org> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3372 Lines: 100 Hi Shanker, On 02/28/2016 08:22 PM, Shanker Donthineni wrote: > We are not checking whether the requested device identifier fits into > the device table memory or not. The function its_create_device() > assumes that enough memory has been allocated for whole DevID sparse space? > (reported by ITS_TYPER.Devbits) during the ITS probe() and continues > to initialize ITS hardware. > > This assumption is not perfect, sometimes we reduce memory size either > because of its size crossing MAX_ORDER-1 or BASERn max size limit. The > MAPD command fails if 'Device ID' is outside of device table range. > > Add a simple validation check to avoid MAPD failures since we are > not handling ITS command errors. This change also helps to return an > error -ENOMEM instead of success to caller. > > Signed-off-by: Shanker Donthineni > --- > [v1]->[v2] > Rebase to v4.5-rc6, edit commit text and simplify code changes > > drivers/irqchip/irq-gic-v3-its.c | 24 ++++++++++++++++++++---- > 1 file changed, 20 insertions(+), 4 deletions(-) > > diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c > index 43dfd15..6d986ac 100644 > --- a/drivers/irqchip/irq-gic-v3-its.c > +++ b/drivers/irqchip/irq-gic-v3-its.c > @@ -55,6 +55,16 @@ struct its_collection { > }; > > /* > + * The ITS_BASER structure - contains memeory information and table typo: memory Reviewed-by: Eric Auger Best Regards Eric > + * entry size in bytes. > + */ > +struct its_baser { > + void *base; > + u32 order; > + u32 entry_size; > +}; > + > +/* > * The ITS structure - contains most of the infrastructure, with the > * top-level MSI domain, the command queue, the collections, and the > * list of devices writing to it. > @@ -66,14 +76,12 @@ struct its_node { > unsigned long phys_base; > struct its_cmd_block *cmd_base; > struct its_cmd_block *cmd_write; > - struct { > - void *base; > - u32 order; > - } tables[GITS_BASER_NR_REGS]; > + struct its_baser tables[GITS_BASER_NR_REGS]; > struct its_collection *collections; > struct list_head its_device_list; > u64 flags; > u32 ite_size; > + struct its_baser *device_table; > }; > > #define ITS_ITT_ALIGN SZ_256 > @@ -860,6 +868,7 @@ static int its_alloc_tables(const char *node_name, struct its_node *its) > * For other tables, only allocate a single page. > */ > if (type == GITS_BASER_TYPE_DEVICE) { > + its->device_table = &its->tables[i]; > /* > * 'order' was initialized earlier to the default page > * granule of the the ITS. We can't have an allocation > @@ -874,6 +883,7 @@ static int its_alloc_tables(const char *node_name, struct its_node *its) > node_name, order); > } > } > + its->tables[i].entry_size = entry_size; > > retry_alloc_baser: > alloc_pages = (PAGE_ORDER_TO_SIZE(order) / psz); > @@ -1152,6 +1162,12 @@ static struct its_device *its_create_device(struct its_node *its, u32 dev_id, > int nr_ites; > int sz; > > + /* Don't allow 'dev_id' that exceeds single, flat table limit */ > + if (its->device_table && > + (dev_id >= (PAGE_ORDER_TO_SIZE(its->device_table->order) / > + its->device_table->entry_size))) > + return NULL; > + > dev = kzalloc(sizeof(*dev), GFP_KERNEL); > /* > * At least one bit of EventID is being used, hence a minimum >