From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gautham R Shenoy Date: Mon, 17 Aug 2015 05:53:59 +0000 Subject: Re: [PATCH] book3s_hv_rmhandlers:Pass the correct trap argument to kvmhv_commence_exit Message-Id: <20150817055345.GA13304@in.ibm.com> List-Id: References: <1432196824-21791-1-git-send-email-ego@linux.vnet.ibm.com> <20150814050728.GB13544@tungsten.ozlabs.ibm.com> In-Reply-To: <20150814050728.GB13544@tungsten.ozlabs.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Sam Bobroff Cc: "Gautham R. Shenoy" , Paul Mackerras , Benjamin Herrenschmidt , Michael Ellerman , linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, kvm-ppc@vger.kernel.org, "Aneesh Kumar K.V" Hi Sam, On Fri, Aug 14, 2015 at 03:07:28PM +1000, Sam Bobroff wrote: > On Thu, May 21, 2015 at 01:57:04PM +0530, Gautham R. Shenoy wrote: > > In guest_exit_cont we call kvmhv_commence_exit which expects the trap > > number as the argument. However r3 doesn't contain the trap number at > > this point and as a result we would be calling the function with a > > spurious trap number. > > > > Fix this by copying r12 into r3 before calling kvmhv_commence_exit as > > r12 contains the trap number > > > > Signed-off-by: Gautham R. Shenoy > > Hi Gautham, > > I agree with your logic: r3 is quite clearly corrupted in that path. So: > > Reviewed-by: Sam Bobroff > > Just one comment: Do you have a case of this causing some visible problem due > to the corrupted trap number? (I'll test the patch if you do.) > Actually no! I found this bug while reviewing the code for some other issue. > Cheers, > Sam. -- Thanks and Regards gautham.