From mboxrd@z Thu Jan 1 00:00:00 1970 From: Laurent Dufour Subject: [PATCH v3 0/2] Tracking user space vDSO remaping Date: Wed, 25 Mar 2015 14:53:50 +0100 Message-ID: References: <20150325121118.GA2542@gmail.com> Return-path: In-Reply-To: <20150325121118.GA2542@gmail.com> Sender: owner-linux-mm@kvack.org To: Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , Jeff Dike , Richard Weinberger , Guan Xuetao , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , x86@kernel.org, Arnd Bergmann , linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org, user-mode-linux-devel@lists.sourceforge.net, user-mode-linux-user@lists.sourceforge.net, linux-arch@vger.kernel.org, linux-mm@kvack.org Cc: cov@codeaurora.org, criu@openvz.org List-Id: linux-arch.vger.kernel.org CRIU is recreating the process memory layout by remapping the checkpointee memory area on top of the current process (criu). This includes remapping the vDSO to the place it has at checkpoint time. However some architectures like powerpc are keeping a reference to the vDSO base address to build the signal return stack frame by calling the vDSO sigreturn service. So once the vDSO has been moved, this reference is no more valid and the signal frame built later are not usable. This patch serie is introducing a new mm hook 'arch_remap' which is called when mremap is done and the mm lock still hold. The next patch is adding the vDSO remap and unmap tracking to the powerpc architecture. Changes in v3: -------------- - Fixed grammatical error in a comment of the second patch. Thanks again, Ingo. Changes in v2: -------------- - Following the Ingo Molnar's advice, enabling the call to arch_remap through the __HAVE_ARCH_REMAP macro. This reduces considerably the first patch. Laurent Dufour (2): mm: Introducing arch_remap hook powerpc/mm: Tracking vDSO remap arch/powerpc/include/asm/mmu_context.h | 36 +++++++++++++++++++++++++++++++++- mm/mremap.c | 11 +++++++++-- 2 files changed, 44 insertions(+), 3 deletions(-) -- 1.9.1 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from e06smtp10.uk.ibm.com ([195.75.94.106]:44134 "EHLO e06smtp10.uk.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752793AbbCYNyJ (ORCPT ); Wed, 25 Mar 2015 09:54:09 -0400 Received: from /spool/local by e06smtp10.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 25 Mar 2015 13:54:07 -0000 From: Laurent Dufour Subject: [PATCH v3 0/2] Tracking user space vDSO remaping Date: Wed, 25 Mar 2015 14:53:50 +0100 Message-ID: In-Reply-To: <20150325121118.GA2542@gmail.com> References: <20150325121118.GA2542@gmail.com> Sender: linux-arch-owner@vger.kernel.org List-ID: To: Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , Jeff Dike , Richard Weinberger , Guan Xuetao , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , x86@kernel.org, Arnd Bergmann , linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org, user-mode-linux-devel@lists.sourceforge.net, user-mode-linux-user@lists.sourceforge.net, linux-arch@vger.kernel.org, linux-mm@kvack.org Cc: cov@codeaurora.org, criu@openvz.org Message-ID: <20150325135350.5d2bEovula0WZcEUraHlu1Eu6AHbYICZd6nANMgX07E@z> CRIU is recreating the process memory layout by remapping the checkpointee memory area on top of the current process (criu). This includes remapping the vDSO to the place it has at checkpoint time. However some architectures like powerpc are keeping a reference to the vDSO base address to build the signal return stack frame by calling the vDSO sigreturn service. So once the vDSO has been moved, this reference is no more valid and the signal frame built later are not usable. This patch serie is introducing a new mm hook 'arch_remap' which is called when mremap is done and the mm lock still hold. The next patch is adding the vDSO remap and unmap tracking to the powerpc architecture. Changes in v3: -------------- - Fixed grammatical error in a comment of the second patch. Thanks again, Ingo. Changes in v2: -------------- - Following the Ingo Molnar's advice, enabling the call to arch_remap through the __HAVE_ARCH_REMAP macro. This reduces considerably the first patch. Laurent Dufour (2): mm: Introducing arch_remap hook powerpc/mm: Tracking vDSO remap arch/powerpc/include/asm/mmu_context.h | 36 +++++++++++++++++++++++++++++++++- mm/mremap.c | 11 +++++++++-- 2 files changed, 44 insertions(+), 3 deletions(-) -- 1.9.1