Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965362Ab2EOCkF (ORCPT ); Mon, 14 May 2012 22:40:05 -0400 Received: from mail.windriver.com ([147.11.1.11]:49785 "EHLO mail.windriver.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964839Ab2EOCRq (ORCPT ); Mon, 14 May 2012 22:17:46 -0400 From: Paul Gortmaker To: , Subject: [34-longterm 130/179] kexec, x86: Fix incorrect jump back address if not preserving context Date: Mon, 14 May 2012 22:13:46 -0400 Message-ID: <1337048075-6132-131-git-send-email-paul.gortmaker@windriver.com> X-Mailer: git-send-email 1.7.9.6 In-Reply-To: <1337048075-6132-1-git-send-email-paul.gortmaker@windriver.com> References: <1337048075-6132-1-git-send-email-paul.gortmaker@windriver.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2436 Lines: 68 From: Huang Ying ------------------- This is a commit scheduled for the next v2.6.34 longterm release. http://git.kernel.org/?p=linux/kernel/git/paulg/longterm-queue-2.6.34.git If you see a problem with using this for longterm, please comment. ------------------- commit 050438ed5a05b25cdf287f5691e56a58c2606997 upstream. In kexec jump support, jump back address passed to the kexeced kernel via function calling ABI, that is, the function call return address is the jump back entry. Furthermore, jump back entry == 0 should be used to signal that the jump back or preserve context is not enabled in the original kernel. But in the current implementation the stack position used for function call return address is not cleared context preservation is disabled. The patch fixes this bug. Reported-and-tested-by: Yin Kangkai Signed-off-by: Huang Ying Cc: Eric W. Biederman Cc: Vivek Goyal Link: http://lkml.kernel.org/r/1310607277-25029-1-git-send-email-ying.huang@intel.com Signed-off-by: Ingo Molnar Signed-off-by: Paul Gortmaker --- arch/x86/kernel/relocate_kernel_32.S | 2 ++ arch/x86/kernel/relocate_kernel_64.S | 2 ++ 2 files changed, 4 insertions(+) diff --git a/arch/x86/kernel/relocate_kernel_32.S b/arch/x86/kernel/relocate_kernel_32.S index 4123553..36818f8 100644 --- a/arch/x86/kernel/relocate_kernel_32.S +++ b/arch/x86/kernel/relocate_kernel_32.S @@ -97,6 +97,8 @@ relocate_kernel: ret identity_mapped: + /* set return address to 0 if not preserving context */ + pushl $0 /* store the start address on the stack */ pushl %edx diff --git a/arch/x86/kernel/relocate_kernel_64.S b/arch/x86/kernel/relocate_kernel_64.S index 4de8f5b..7a6f3b3 100644 --- a/arch/x86/kernel/relocate_kernel_64.S +++ b/arch/x86/kernel/relocate_kernel_64.S @@ -100,6 +100,8 @@ relocate_kernel: ret identity_mapped: + /* set return address to 0 if not preserving context */ + pushq $0 /* store the start address on the stack */ pushq %rdx -- 1.7.9.6 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/