From patchwork Mon Nov 23 09:54:30 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mike Rapoport X-Patchwork-Id: 11924803 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=-19.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 25D00C8300B for ; Mon, 23 Nov 2020 09:56:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C571A206F7 for ; Mon, 23 Nov 2020 09:56:29 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="e4Ew5z4M" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728503AbgKWJ4J (ORCPT ); Mon, 23 Nov 2020 04:56:09 -0500 Received: from mail.kernel.org ([198.145.29.99]:59506 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728493AbgKWJ4I (ORCPT ); Mon, 23 Nov 2020 04:56:08 -0500 Received: from aquarius.haifa.ibm.com (nesher1.haifa.il.ibm.com [195.110.40.7]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 62152208DB; Mon, 23 Nov 2020 09:55:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1606125367; bh=x9rsWynUSj92xJxzciKz2wcsB6wApkMO1t2A4HXerbs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=e4Ew5z4MgueMaSbcUhMrw9rF1X02/V4jDf+Y5PgvaJadcmM6PDhrV5w/HKj+ZwLXE 06Jbng4H5og2FBoK/OcryaIcLzQEj6UQnLW3QfGnMCFj0Lty4rsA2W3W5QCk1GicuE 1tnp3Q6tL8d1GhnvQmbjW2qKIPYMh4lgs8aL2AzI= From: Mike Rapoport To: Andrew Morton Cc: Alexander Viro , Andy Lutomirski , Arnd Bergmann , Borislav Petkov , Catalin Marinas , Christopher Lameter , Dan Williams , Dave Hansen , David Hildenbrand , Elena Reshetova , "H. Peter Anvin" , Ingo Molnar , James Bottomley , "Kirill A. Shutemov" , Matthew Wilcox , Mark Rutland , Mike Rapoport , Mike Rapoport , Michael Kerrisk , Palmer Dabbelt , Paul Walmsley , Peter Zijlstra , Rick Edgecombe , Roman Gushchin , Shuah Khan , Thomas Gleixner , Tycho Andersen , Will Deacon , linux-api@vger.kernel.org, linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-nvdimm@lists.01.org, linux-riscv@lists.infradead.org, x86@kernel.org Subject: [PATCH v10 7/9] PM: hibernate: disable when there are active secretmem users Date: Mon, 23 Nov 2020 11:54:30 +0200 Message-Id: <20201123095432.5860-8-rppt@kernel.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20201123095432.5860-1-rppt@kernel.org> References: <20201123095432.5860-1-rppt@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org From: Mike Rapoport It is unsafe to allow saving of secretmem areas to the hibernation snapshot as they would be visible after the resume and this essentially will defeat the purpose of secret memory mappings. Prevent hibernation whenever there are active secret memory users. Signed-off-by: Mike Rapoport --- include/linux/secretmem.h | 6 ++++++ kernel/power/hibernate.c | 5 ++++- mm/secretmem.c | 15 +++++++++++++++ 3 files changed, 25 insertions(+), 1 deletion(-) diff --git a/include/linux/secretmem.h b/include/linux/secretmem.h index 70e7db9f94fe..907a6734059c 100644 --- a/include/linux/secretmem.h +++ b/include/linux/secretmem.h @@ -6,6 +6,7 @@ bool vma_is_secretmem(struct vm_area_struct *vma); bool page_is_secretmem(struct page *page); +bool secretmem_active(void); #else @@ -19,6 +20,11 @@ static inline bool page_is_secretmem(struct page *page) return false; } +static inline bool secretmem_active(void) +{ + return false; +} + #endif /* CONFIG_SECRETMEM */ #endif /* _LINUX_SECRETMEM_H */ diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c index da0b41914177..559acef3fddb 100644 --- a/kernel/power/hibernate.c +++ b/kernel/power/hibernate.c @@ -31,6 +31,7 @@ #include #include #include +#include #include #include "power.h" @@ -81,7 +82,9 @@ void hibernate_release(void) bool hibernation_available(void) { - return nohibernate == 0 && !security_locked_down(LOCKDOWN_HIBERNATION); + return nohibernate == 0 && + !security_locked_down(LOCKDOWN_HIBERNATION) && + !secretmem_active(); } /** diff --git a/mm/secretmem.c b/mm/secretmem.c index abf6ecdf70cb..14ef439841c9 100644 --- a/mm/secretmem.c +++ b/mm/secretmem.c @@ -51,6 +51,13 @@ struct secretmem_ctx { static struct cma *secretmem_cma; +static atomic_t secretmem_users; + +bool secretmem_active(void) +{ + return !!atomic_read(&secretmem_users); +} + static int secretmem_account_pages(struct page *page, gfp_t gfp, int order) { int err; @@ -185,6 +192,12 @@ static const struct vm_operations_struct secretmem_vm_ops = { .fault = secretmem_fault, }; +static int secretmem_release(struct inode *inode, struct file *file) +{ + atomic_dec(&secretmem_users); + return 0; +} + static int secretmem_mmap(struct file *file, struct vm_area_struct *vma) { struct secretmem_ctx *ctx = file->private_data; @@ -211,6 +224,7 @@ bool vma_is_secretmem(struct vm_area_struct *vma) } static const struct file_operations secretmem_fops = { + .release = secretmem_release, .mmap = secretmem_mmap, }; @@ -328,6 +342,7 @@ SYSCALL_DEFINE1(memfd_secret, unsigned long, flags) file->f_flags |= O_LARGEFILE; fd_install(fd, file); + atomic_inc(&secretmem_users); return fd; err_put_fd: