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=-13.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 5839CC11F6A for ; Thu, 8 Jul 2021 01:08:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 468B561CD4 for ; Thu, 8 Jul 2021 01:08:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230123AbhGHBKv (ORCPT ); Wed, 7 Jul 2021 21:10:51 -0400 Received: from mail.kernel.org ([198.145.29.99]:50760 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230111AbhGHBKt (ORCPT ); Wed, 7 Jul 2021 21:10:49 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 9119861CCF; Thu, 8 Jul 2021 01:08:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1625706488; bh=UwC1xKQ66RJjSS8Lm5HR4sog8UZ4rbFsKgiRsF29CTE=; h=Date:From:To:Subject:In-Reply-To:From; b=wzbeP+o1fiFEWSsU1NTumoplIXCQixQblfscc/FjNZezbwPeTzGThJIGq5rMkgQ3b BPWvQvAFV6k5E4/iNEarroCm8+ee98xxUFxs5Dtj1NgCxrMGmGdOccMKVpKUzanmrR I7jWi0OhTBiSMID3tBE7I26O8yf+p7o91dvJrRL0= Date: Wed, 07 Jul 2021 18:08:07 -0700 From: Andrew Morton To: akpm@linux-foundation.org, arnd@arndb.de, bp@alien8.de, catalin.marinas@arm.com, cl@linux.com, dan.j.williams@intel.com, dave.hansen@linux.intel.com, david@redhat.com, elena.reshetova@intel.com, guro@fb.com, hagen@jauu.net, hpa@zytor.com, James.Bottomley@HansenPartnership.com, jejb@linux.ibm.com, kirill@shutemov.name, linux-mm@kvack.org, lkp@intel.com, luto@kernel.org, mark.rutland@arm.com, mingo@redhat.com, mm-commits@vger.kernel.org, mtk.manpages@gmail.com, palmer@dabbelt.com, palmerdabbelt@google.com, paul.walmsley@sifive.com, peterz@infradead.org, rick.p.edgecombe@intel.com, rppt@linux.ibm.com, shakeelb@google.com, shuah@kernel.org, tglx@linutronix.de, torvalds@linux-foundation.org, tycho@tycho.ws, viro@zeniv.linux.org.uk, will@kernel.org, willy@infradead.org Subject: [patch 12/54] PM: hibernate: disable when there are active secretmem users Message-ID: <20210708010807.hHILhs811%akpm@linux-foundation.org> In-Reply-To: <20210707175950.eceddb86c6c555555d4730e2@linux-foundation.org> User-Agent: s-nail v14.8.16 Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org From: Mike Rapoport Subject: PM: hibernate: disable when there are active secretmem users 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. Link: https://lkml.kernel.org/r/20210518072034.31572-6-rppt@kernel.org Signed-off-by: Mike Rapoport Acked-by: David Hildenbrand Acked-by: James Bottomley Cc: Alexander Viro Cc: Andy Lutomirski Cc: Arnd Bergmann Cc: Borislav Petkov Cc: Catalin Marinas Cc: Christopher Lameter Cc: Dan Williams Cc: Dave Hansen Cc: David Hildenbrand Cc: Elena Reshetova Cc: Hagen Paul Pfeifer Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: James Bottomley Cc: "Kirill A. Shutemov" Cc: Mark Rutland Cc: Matthew Wilcox Cc: Michael Kerrisk Cc: Palmer Dabbelt Cc: Palmer Dabbelt Cc: Paul Walmsley Cc: Peter Zijlstra Cc: Rick Edgecombe Cc: Roman Gushchin Cc: Shakeel Butt Cc: Shuah Khan Cc: Thomas Gleixner Cc: Tycho Andersen Cc: Will Deacon Cc: kernel test robot Signed-off-by: Andrew Morton --- include/linux/secretmem.h | 6 ++++++ kernel/power/hibernate.c | 5 ++++- mm/secretmem.c | 15 +++++++++++++++ 3 files changed, 25 insertions(+), 1 deletion(-) --- a/include/linux/secretmem.h~pm-hibernate-disable-when-there-are-active-secretmem-users +++ a/include/linux/secretmem.h @@ -30,6 +30,7 @@ static inline bool page_is_secretmem(str } bool vma_is_secretmem(struct vm_area_struct *vma); +bool secretmem_active(void); #else @@ -42,6 +43,11 @@ static inline bool page_is_secretmem(str { return false; } + +static inline bool secretmem_active(void) +{ + return false; +} #endif /* CONFIG_SECRETMEM */ --- a/kernel/power/hibernate.c~pm-hibernate-disable-when-there-are-active-secretmem-users +++ a/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(); } /** --- a/mm/secretmem.c~pm-hibernate-disable-when-there-are-active-secretmem-users +++ a/mm/secretmem.c @@ -40,6 +40,13 @@ module_param_named(enable, secretmem_ena MODULE_PARM_DESC(secretmem_enable, "Enable secretmem and memfd_secret(2) system call"); +static atomic_t secretmem_users; + +bool secretmem_active(void) +{ + return !!atomic_read(&secretmem_users); +} + static vm_fault_t secretmem_fault(struct vm_fault *vmf) { struct address_space *mapping = vmf->vma->vm_file->f_mapping; @@ -94,6 +101,12 @@ static const struct vm_operations_struct .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) { unsigned long len = vma->vm_end - vma->vm_start; @@ -116,6 +129,7 @@ bool vma_is_secretmem(struct vm_area_str } static const struct file_operations secretmem_fops = { + .release = secretmem_release, .mmap = secretmem_mmap, }; @@ -202,6 +216,7 @@ SYSCALL_DEFINE1(memfd_secret, unsigned i file->f_flags |= O_LARGEFILE; fd_install(fd, file); + atomic_inc(&secretmem_users); return fd; err_put_fd: _