From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wi0-f169.google.com (mail-wi0-f169.google.com [209.85.212.169]) by kanga.kvack.org (Postfix) with ESMTP id EE9FD6B0032 for ; Thu, 26 Mar 2015 13:38:02 -0400 (EDT) Received: by wibbg6 with SMTP id bg6so73495792wib.0 for ; Thu, 26 Mar 2015 10:38:02 -0700 (PDT) Received: from e06smtp15.uk.ibm.com (e06smtp15.uk.ibm.com. [195.75.94.111]) by mx.google.com with ESMTPS id ln14si11798782wic.10.2015.03.26.10.38.01 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Thu, 26 Mar 2015 10:38:01 -0700 (PDT) Received: from /spool/local by e06smtp15.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Thu, 26 Mar 2015 17:38:00 -0000 Received: from b06cxnps4074.portsmouth.uk.ibm.com (d06relay11.portsmouth.uk.ibm.com [9.149.109.196]) by d06dlp01.portsmouth.uk.ibm.com (Postfix) with ESMTP id 8669B17D8056 for ; Thu, 26 Mar 2015 17:38:23 +0000 (GMT) Received: from d06av10.portsmouth.uk.ibm.com (d06av10.portsmouth.uk.ibm.com [9.149.37.251]) by b06cxnps4074.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id t2QHbtbJ3866896 for ; Thu, 26 Mar 2015 17:37:55 GMT Received: from d06av10.portsmouth.uk.ibm.com (localhost [127.0.0.1]) by d06av10.portsmouth.uk.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id t2QHbsbU032124 for ; Thu, 26 Mar 2015 11:37:55 -0600 From: Laurent Dufour Subject: [PATCH v4 0/2] Tracking user space vDSO remaping Date: Thu, 26 Mar 2015 18:37:51 +0100 Message-Id: In-Reply-To: <20150326141730.GA23060@gmail.com> References: <20150326141730.GA23060@gmail.com> Sender: owner-linux-mm@kvack.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 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 v4: -------------- - Reviewing the PowerPC part of the patch to handle partial unmap and remap of the vDSO. 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 | 32 +++++++++++++++++++++++++++- arch/powerpc/kernel/vdso.c | 39 ++++++++++++++++++++++++++++++++++ mm/mremap.c | 11 ++++++++-- 3 files changed, 79 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