From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752574AbbCTRDN (ORCPT ); Fri, 20 Mar 2015 13:03:13 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:50992 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751484AbbCTRDJ (ORCPT ); Fri, 20 Mar 2015 13:03:09 -0400 Message-ID: <1426870978.13401.7.camel@fourier> Subject: Re: [PATCH 3.13.y-ckt 71/80] MIPS: Fix C0_Pagegrain[IEC] support. From: Kamal Mostafa To: David Daney Cc: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com, David Daney , Leonid Yegoshin , linux-mips@linux-mips.org, Ralf Baechle Date: Fri, 20 Mar 2015 10:02:58 -0700 In-Reply-To: <550B575D.8090908@caviumnetworks.com> References: <1426804568-2907-1-git-send-email-kamal@canonical.com> <1426804568-2907-72-git-send-email-kamal@canonical.com> <550B575D.8090908@caviumnetworks.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.10.4-0ubuntu2 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 2015-03-19 at 16:10 -0700, David Daney wrote: > On 03/19/2015 03:35 PM, Kamal Mostafa wrote: > > 3.13.11-ckt17 -stable review patch. If anyone has any objections, please let me know. > > > > Read the patch commentary. It should only be applied to 3.17 and later. > > So: NACK. > Thanks very much for reviewing this, David. Dropped from 3.13-stable. Also FYI, if you append e.g. "# 3.17+" to your Cc: stable line, that will help the stable maintainers (more specifically, will help our automated tools ;-) recognize where the patch should and shouldn't be applied. Example: Cc: # 3.17+ -Kamal > > ------------------ > > > > From: David Daney > > > > commit 9ead8632bbf454cfc709b6205dc9cd8582fb0d64 upstream. > > > > The following commits: > > > > 5890f70f15c52d (MIPS: Use dedicated exception handler if CPU supports RI/XI exceptions) > > 6575b1d4173eae (MIPS: kernel: cpu-probe: Detect unique RI/XI exceptions) > > > > break the kernel for *all* existing MIPS CPUs that implement the > > CP0_PageGrain[IEC] bit. They cause the TLB exception handlers to be > > generated without the legacy execute-inhibit handling, but never set > > the CP0_PageGrain[IEC] bit to activate the use of dedicated exception > > vectors for execute-inhibit exceptions. The result is that upon > > detection of an execute-inhibit violation, we loop forever in the TLB > > exception handlers instead of sending SIGSEGV to the task. > > > > If we are generating TLB exception handlers expecting separate > > vectors, we must also enable the CP0_PageGrain[IEC] feature. > > > > The bug was introduced in kernel version 3.17. > > > > Signed-off-by: David Daney > > Cc: Leonid Yegoshin > > Cc: linux-mips@linux-mips.org > > Patchwork: http://patchwork.linux-mips.org/patch/8880/ > > Signed-off-by: Ralf Baechle > > Signed-off-by: Kamal Mostafa > > --- > > arch/mips/mm/tlb-r4k.c | 2 ++ > > 1 file changed, 2 insertions(+) > > > > diff --git a/arch/mips/mm/tlb-r4k.c b/arch/mips/mm/tlb-r4k.c > > index da3b0b9..d04fe4e 100644 > > --- a/arch/mips/mm/tlb-r4k.c > > +++ b/arch/mips/mm/tlb-r4k.c > > @@ -429,6 +429,8 @@ void tlb_init(void) > > #ifdef CONFIG_64BIT > > pg |= PG_ELPA; > > #endif > > + if (cpu_has_rixiex) > > + pg |= PG_IEC; > > write_c0_pagegrain(pg); > > } > > > > >