From patchwork Fri Feb 21 12:59:51 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Luis Henriques X-Patchwork-Id: 322785 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from huckleberry.canonical.com (huckleberry.canonical.com [91.189.94.19]) by ozlabs.org (Postfix) with ESMTP id CD6742C00CC for ; Sat, 22 Feb 2014 00:00:30 +1100 (EST) Received: from localhost ([127.0.0.1] helo=huckleberry.canonical.com) by huckleberry.canonical.com with esmtp (Exim 4.76) (envelope-from ) id 1WGpiN-0004rV-GS; Fri, 21 Feb 2014 13:00:27 +0000 Received: from youngberry.canonical.com ([91.189.89.112]) by huckleberry.canonical.com with esmtp (Exim 4.76) (envelope-from ) id 1WGpho-0004XO-O9 for kernel-team@lists.ubuntu.com; Fri, 21 Feb 2014 12:59:52 +0000 Received: from bl20-128-115.dsl.telepac.pt ([2.81.128.115] helo=localhost) by youngberry.canonical.com with esmtpsa (TLS1.0:DHE_RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1WGpho-0002Uf-GS; Fri, 21 Feb 2014 12:59:52 +0000 From: Luis Henriques To: Martin Schwidefsky Subject: [3.5.y.z extended stable] Patch "s390: fix kernel crash due to linkage stack instructions" has been added to staging queue Date: Fri, 21 Feb 2014 12:59:51 +0000 Message-Id: <1392987591-15009-1-git-send-email-luis.henriques@canonical.com> X-Mailer: git-send-email 1.9.0 X-Extended-Stable: 3.5 Cc: kernel-team@lists.ubuntu.com X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.14 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: kernel-team-bounces@lists.ubuntu.com Sender: kernel-team-bounces@lists.ubuntu.com This is a note to let you know that I have just added a patch titled s390: fix kernel crash due to linkage stack instructions to the linux-3.5.y-queue branch of the 3.5.y.z extended stable tree which can be found at: http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.5.y-queue If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.5.y.z tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Luis ------ From a8877579c9d33cec16913b55dce048797daac97d Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Mon, 3 Feb 2014 17:37:15 +0100 Subject: s390: fix kernel crash due to linkage stack instructions commit 8d7f6690cedb83456edd41c9bd583783f0703bf0 upstream. The kernel currently crashes with a low-address-protection exception if a user space process executes an instruction that tries to use the linkage stack. Set the base-ASTE origin and the subspace-ASTE origin of the dispatchable-unit-control-table to point to a dummy ASTE. Set up control register 15 to point to an empty linkage stack with no room left. A user space process with a linkage stack instruction will still crash but with a different exception which is correctly translated to a segmentation fault instead of a kernel oops. Signed-off-by: Martin Schwidefsky Signed-off-by: Luis Henriques --- arch/s390/kernel/head64.S | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) -- 1.9.0 diff --git a/arch/s390/kernel/head64.S b/arch/s390/kernel/head64.S index 99348c0..78be245 100644 --- a/arch/s390/kernel/head64.S +++ b/arch/s390/kernel/head64.S @@ -61,7 +61,7 @@ ENTRY(startup_continue) .quad 0 # cr12: tracing off .quad 0 # cr13: home space segment table .quad 0xc0000000 # cr14: machine check handling off - .quad 0 # cr15: linkage stack operations + .quad .Llinkage_stack # cr15: linkage stack operations .Lpcmsk:.quad 0x0000000180000000 .L4malign:.quad 0xffffffffffc00000 .Lscan2g:.quad 0x80000000 + 0x20000 - 8 # 2GB + 128K - 8 @@ -69,12 +69,15 @@ ENTRY(startup_continue) .Lparmaddr: .quad PARMAREA .align 64 -.Lduct: .long 0,0,0,0,.Lduald,0,0,0 +.Lduct: .long 0,.Laste,.Laste,0,.Lduald,0,0,0 .long 0,0,0,0,0,0,0,0 +.Laste: .quad 0,0xffffffffffffffff,0,0,0,0,0,0 .align 128 .Lduald:.rept 8 .long 0x80000000,0,0,0 # invalid access-list entries .endr +.Llinkage_stack: + .long 0,0,0x89000000,0,0,0,0x8a000000,0 ENTRY(_ehead)