From mboxrd@z Thu Jan 1 00:00:00 1970 From: Grant Likely Subject: Re: [PATCH] ARM: kernel: fix nr_cpu_ids check in DT logical map init Date: Thu, 22 Nov 2012 15:33:36 +0000 Message-ID: <20121122153337.083D73E129E@localhost> References: <1353516176-12929-1-git-send-email-lorenzo.pieralisi@arm.com> <20121122120843.GA16972@e102568-lin.cambridge.arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20121122120843.GA16972-7AyDDHkRsp3ZROr8t4l/smS4ubULX0JqMm0uRHvK7Nw@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: devicetree-discuss-bounces+gldd-devicetree-discuss=m.gmane.org-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org Sender: "devicetree-discuss" To: Lorenzo Pieralisi , "linux-lFZ/pmaqli7XmaaqVzeoHQ@public.gmane.org" Cc: "devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org" , "linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org" List-Id: devicetree@vger.kernel.org On Thu, 22 Nov 2012 12:08:43 +0000, Lorenzo Pieralisi wrote: > Hi Russell, > > On Wed, Nov 21, 2012 at 04:42:56PM +0000, Lorenzo Pieralisi wrote: > > If a kernel is configured with a DT containing more /cpu nodes than > > nr_cpu_ids, the number of cpus must be capped in the DT parsing > > code. Current code carries out the check, but fails to cap the > > value and the check is executed after the cpu logical index is used, > > which can lead to memory corruption due to index overflow. > > > > This patch refactors the check against nr_cpu_ids and move it before > > any computed index is used in the parsing code. > > > > Signed-off-by: Lorenzo Pieralisi > > Reported-by: Mark Rutland > > --- > > Russell, > > > > while refactoring the DT loop over nodes, I unfortunately missed this niggle > > in the parsing loop that Mark reported. Here is the fix, sorry for the > > additional commit, if it is ok for you I will add it to your patch system. > > > > Apologies and thanks, > > Lorenzo > > > > arch/arm/kernel/devtree.c | 10 +++++++--- > > 1 file changed, 7 insertions(+), 3 deletions(-) > > > > diff --git a/arch/arm/kernel/devtree.c b/arch/arm/kernel/devtree.c > > index aaf9add..70f1bde 100644 > > --- a/arch/arm/kernel/devtree.c > > +++ b/arch/arm/kernel/devtree.c > > @@ -139,10 +139,14 @@ void __init arm_dt_init_cpu_maps(void) > > i = cpuidx++; > > } > > > > - tmp_map[i] = hwid; > > - > > - if (cpuidx > nr_cpu_ids) > > + if (WARN(cpuidx > nr_cpu_ids, "DT /cpu %u nodes greater than " > > + "max cores %u, capping them\n", > > + cpuidx, nr_cpu_ids)) { > > + cpuidx = nr_cpu_ids; > > break; > > + } > > + > > + tmp_map[i] = hwid; > > } > > > > if (WARN(!bootcpu_valid, "DT missing boot CPU MPIDR[23:0], " > > If it looks fine to you, can I queue this simple fix in your patch > system please ? > > Thanks and apologies for the extra commit, > Lorenzo Acked-by: Grant Likely