From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pl0-f69.google.com (mail-pl0-f69.google.com [209.85.160.69]) by kanga.kvack.org (Postfix) with ESMTP id 54E5C6B0010 for ; Tue, 17 Jul 2018 07:21:49 -0400 (EDT) Received: by mail-pl0-f69.google.com with SMTP id q18-v6so464554pll.3 for ; Tue, 17 Jul 2018 04:21:49 -0700 (PDT) Received: from mga07.intel.com (mga07.intel.com. [134.134.136.100]) by mx.google.com with ESMTPS id 186-v6si752417pff.270.2018.07.17.04.21.48 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 17 Jul 2018 04:21:48 -0700 (PDT) From: "Kirill A. Shutemov" Subject: [PATCHv5 03/19] mm/ksm: Do not merge pages with different KeyIDs Date: Tue, 17 Jul 2018 14:20:13 +0300 Message-Id: <20180717112029.42378-4-kirill.shutemov@linux.intel.com> In-Reply-To: <20180717112029.42378-1-kirill.shutemov@linux.intel.com> References: <20180717112029.42378-1-kirill.shutemov@linux.intel.com> Sender: owner-linux-mm@kvack.org List-ID: To: Ingo Molnar , x86@kernel.org, Thomas Gleixner , "H. Peter Anvin" , Tom Lendacky Cc: Dave Hansen , Kai Huang , Jacob Pan , linux-kernel@vger.kernel.org, linux-mm@kvack.org, "Kirill A. Shutemov" Pages encrypted with different encryption keys are not allowed to be merged by KSM. Otherwise it would cross security boundary. Signed-off-by: Kirill A. Shutemov --- include/linux/mm.h | 7 +++++++ mm/ksm.c | 3 +++ 2 files changed, 10 insertions(+) diff --git a/include/linux/mm.h b/include/linux/mm.h index 151d6e6b16e5..a4ce26aa0b65 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1551,6 +1551,13 @@ static inline int vma_keyid(struct vm_area_struct *vma) } #endif +#ifndef page_keyid +static inline int page_keyid(struct page *page) +{ + return 0; +} +#endif + #ifdef CONFIG_SHMEM /* * The vma_is_shmem is not inline because it is used only by slow diff --git a/mm/ksm.c b/mm/ksm.c index a6d43cf9a982..1bd7b9710e29 100644 --- a/mm/ksm.c +++ b/mm/ksm.c @@ -1214,6 +1214,9 @@ static int try_to_merge_one_page(struct vm_area_struct *vma, if (!PageAnon(page)) goto out; + if (page_keyid(page) != page_keyid(kpage)) + goto out; + /* * We need the page lock to read a stable PageSwapCache in * write_protect_page(). We use trylock_page() instead of -- 2.18.0