From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lorenzo Pieralisi Subject: Re: [PATCH] ARM: kernel: fix nr_cpu_ids check in DT logical map init Date: Thu, 22 Nov 2012 17:05:39 +0000 Message-ID: <20121122170538.GF16972@e102568-lin.cambridge.arm.com> References: <1353516176-12929-1-git-send-email-lorenzo.pieralisi@arm.com> <20121122120843.GA16972@e102568-lin.cambridge.arm.com> <20121122153337.083D73E129E@localhost> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20121122153337.083D73E129E@localhost> Content-Disposition: inline List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-arm-kernel-bounces@lists.infradead.org Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: Grant Likely Cc: "devicetree-discuss@lists.ozlabs.org" , "linux@arm.linux.org.uk" , "linux-arm-kernel@lists.infradead.org" List-Id: devicetree@vger.kernel.org On Thu, Nov 22, 2012 at 03:33:36PM +0000, Grant Likely wrote: > 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 Thanks a lot Grant. Queued with ID: 7585/1 Thanks, Lorenzo