From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id F1253C433E0 for ; Wed, 24 Jun 2020 08:33:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C6C4E20823 for ; Wed, 24 Jun 2020 08:33:37 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="f0I2N5m0" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390397AbgFXIdg (ORCPT ); Wed, 24 Jun 2020 04:33:36 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52098 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389050AbgFXId3 (ORCPT ); Wed, 24 Jun 2020 04:33:29 -0400 Received: from mail-pj1-x1044.google.com (mail-pj1-x1044.google.com [IPv6:2607:f8b0:4864:20::1044]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 52D74C0613ED for ; Wed, 24 Jun 2020 01:33:29 -0700 (PDT) Received: by mail-pj1-x1044.google.com with SMTP id ev7so385718pjb.2 for ; Wed, 24 Jun 2020 01:33:29 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=+phrT2AIdF4lRnMSVXuWInx9nAkEBMgCLH5q3WFhgHA=; b=f0I2N5m0fzWQAgaAToovJ+mgoHHV7sYYaDPhna45YTff7YHh0Z+1WKoPHFzeCDQ1uf eBz5MFamNgglzinB3hqAsBNG1jzQ/4rOcvpqgYHf9aMtvePAoWLBJ/PGHVh67cfqUDng WzLJVQs7gQS+sPPeDBKkHbqBAwu6AYEMSP5BMTS5I7YzfK2JREj0qLqfWOT2ax/UxLf8 jFDzntIjEjnzqf4tq9nLYdezKdRkmuWinYkNilFKVBRf+/F7OH8vrtiy9Gw7TkoB8C4z L8J+EAIpZy4EvhwSQt34sSakOsD4GC2jtggLvm6Gc0nlROno9P7xygb1qqoVJMS+L/2+ 9aGQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=+phrT2AIdF4lRnMSVXuWInx9nAkEBMgCLH5q3WFhgHA=; b=BNTCdsP4OglUUk2HxdkFR5t6+FP1VF5DUiU6dGNUUcBCv0/HRGEXcaADragIKRopIm nGSBR/iil32wS5xrjMImmWqZ/BGHZ2BUSCXdLYhFek8cttuDwPqGuCEs8tvYB8nP/hH/ NoHT+I3QcKqPgArympYzpKBDMORWNctugjC3FQROHzIkJPzCgtSr0wpiow5gnWSD1sZX 5JoHo1MegGsicJKvnd1zXHm2WwE3uUYyfcFTYmLkcdeJ2wYES81bHFYiS/t6nW+rJ4Yi cXCTv4fJdT+voFOWhxlVZbCF+2UHlTbZPcbaEc1x4J9Utrwc/nx4nMj0n7wXb5QxuPFt flUQ== X-Gm-Message-State: AOAM5320XIFMahCfVT0/y+SPp9EFZVZO23yyBCrzV+y+1VSqNUAUwWMy Y86sw9RiFUDGj9E1b/umsJs= X-Google-Smtp-Source: ABdhPJxEt2RHWxak+h/6okxR79SS4HgDc3N0nuv8EGttbDypYw9/wQ+ih8+B+khvyDujbln0caVp5g== X-Received: by 2002:a17:902:d896:: with SMTP id b22mr21427195plz.87.1592987608751; Wed, 24 Jun 2020 01:33:28 -0700 (PDT) Received: from laptop.hsd1.wa.comcast.net ([2601:600:9b7f:872e:a655:30fb:7373:c762]) by smtp.gmail.com with ESMTPSA id g17sm4558614pju.11.2020.06.24.01.33.27 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 24 Jun 2020 01:33:28 -0700 (PDT) From: Andrei Vagin To: Catalin Marinas , Will Deacon , Mark Rutland Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Vincenzo Frascino , Thomas Gleixner , Dmitry Safonov , Christian Brauner , Andrei Vagin Subject: [PATCH 5/6] arm64/vdso: Restrict splitting VVAR VMA Date: Wed, 24 Jun 2020 01:33:20 -0700 Message-Id: <20200624083321.144975-6-avagin@gmail.com> X-Mailer: git-send-email 2.17.2 In-Reply-To: <20200624083321.144975-1-avagin@gmail.com> References: <20200624083321.144975-1-avagin@gmail.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Forbid splitting VVAR VMA resulting in a stricter ABI and reducing the amount of corner-cases to consider while working further on VDSO time namespace support. As the offset from timens to VVAR page is computed compile-time, the pages in VVAR should stay together and not being partically mremap()'ed. Reviewed-by: Vincenzo Frascino Reviewed-by: Dmitry Safonov Signed-off-by: Andrei Vagin --- arch/arm64/kernel/vdso.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/arch/arm64/kernel/vdso.c b/arch/arm64/kernel/vdso.c index be9ca8c46cff..8be6bd6625db 100644 --- a/arch/arm64/kernel/vdso.c +++ b/arch/arm64/kernel/vdso.c @@ -224,6 +224,17 @@ static vm_fault_t vvar_fault(const struct vm_special_mapping *sm, return vmf_insert_pfn(vma, vmf->address, pfn); } +static int vvar_mremap(const struct vm_special_mapping *sm, + struct vm_area_struct *new_vma) +{ + unsigned long new_size = new_vma->vm_end - new_vma->vm_start; + + if (new_size != VVAR_NR_PAGES * PAGE_SIZE) + return -EINVAL; + + return 0; +} + static int __setup_additional_pages(enum vdso_abi abi, struct mm_struct *mm, struct linux_binprm *bprm, @@ -306,6 +317,7 @@ static struct vm_special_mapping aarch32_vdso_maps[] = { [AA32_MAP_VVAR] = { .name = "[vvar]", .fault = vvar_fault, + .mremap = vvar_mremap, }, [AA32_MAP_VDSO] = { .name = "[vdso]", @@ -474,6 +486,7 @@ static struct vm_special_mapping aarch64_vdso_maps[] __ro_after_init = { [AA64_MAP_VVAR] = { .name = "[vvar]", .fault = vvar_fault, + .mremap = vvar_mremap, }, [AA64_MAP_VDSO] = { .name = "[vdso]", -- 2.24.1