From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751870AbdLNLnm (ORCPT ); Thu, 14 Dec 2017 06:43:42 -0500 Received: from bombadil.infradead.org ([65.50.211.133]:47507 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751198AbdLNLnk (ORCPT ); Thu, 14 Dec 2017 06:43:40 -0500 Message-Id: <20171214113851.547977641@infradead.org> User-Agent: quilt/0.63-1 Date: Thu, 14 Dec 2017 12:27:35 +0100 From: Peter Zijlstra To: linux-kernel@vger.kernel.org, tglx@linutronix.de Cc: x86@kernel.org, Linus Torvalds , Andy Lutomirsky , Peter Zijlstra , Dave Hansen , Borislav Petkov , Greg KH , keescook@google.com, hughd@google.com, Brian Gerst , Josh Poimboeuf , Denys Vlasenko , Boris Ostrovsky , Juergen Gross , David Laight , Eduardo Valentin , aliguori@amazon.com, Will Deacon , linux-mm@kvack.org, kirill.shutemov@linux.intel.com, dan.j.williams@intel.com Subject: [PATCH v2 09/17] mm: Provide vm_special_mapping::close References: <20171214112726.742649793@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline; filename=mm--Provide-vm_special_mapping--close.patch Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Peter Zijlstra Userspace can (malisiously) munmap() the VMAs injected into its memory map through install_special_mapping(). In order to ensure there are no hardware resources tied to the mapping, we need a close callback. Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Thomas Gleixner --- include/linux/mm_types.h | 3 +++ mm/mmap.c | 4 ++++ 2 files changed, 7 insertions(+) --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -644,6 +644,9 @@ struct vm_special_mapping { int (*mremap)(const struct vm_special_mapping *sm, struct vm_area_struct *new_vma); + + void (*close)(const struct vm_special_mapping *sm, + struct vm_area_struct *vma); }; enum tlb_flush_reason { --- a/mm/mmap.c +++ b/mm/mmap.c @@ -3206,6 +3206,10 @@ static int special_mapping_fault(struct */ static void special_mapping_close(struct vm_area_struct *vma) { + struct vm_special_mapping *sm = vma->vm_private_data; + + if (sm->close) + sm->close(sm, vma); } static const char *special_mapping_name(struct vm_area_struct *vma)