From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on archive.lwn.net X-Spam-Level: X-Spam-Status: No, score=-5.7 required=5.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI,SPF_HELO_NONE,SPF_NONE autolearn=ham autolearn_force=no version=3.4.2 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by archive.lwn.net (Postfix) with ESMTP id 718757D922 for ; Thu, 15 Aug 2019 15:44:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730842AbfHOPoL (ORCPT ); Thu, 15 Aug 2019 11:44:11 -0400 Received: from foss.arm.com ([217.140.110.172]:45722 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729975AbfHOPoL (ORCPT ); Thu, 15 Aug 2019 11:44:11 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id C2835360; Thu, 15 Aug 2019 08:44:09 -0700 (PDT) Received: from arrakis.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.121.207.14]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 1A9763F706; Thu, 15 Aug 2019 08:44:07 -0700 (PDT) From: Catalin Marinas To: linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org Cc: Andrew Morton , Vincenzo Frascino , Will Deacon , Andrey Konovalov , Szabolcs Nagy , Kevin Brodsky , Dave P Martin , Dave Hansen , linux-doc@vger.kernel.org, linux-arch@vger.kernel.org Subject: [PATCH v8 1/5] mm: untag user pointers in mmap/munmap/mremap/brk Date: Thu, 15 Aug 2019 16:43:59 +0100 Message-Id: <20190815154403.16473-2-catalin.marinas@arm.com> X-Mailer: git-send-email 2.23.0.rc0 In-Reply-To: <20190815154403.16473-1-catalin.marinas@arm.com> References: <20190815154403.16473-1-catalin.marinas@arm.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-doc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org There isn't a good reason to differentiate between the user address space layout modification syscalls and the other memory permission/attributes ones (e.g. mprotect, madvise) w.r.t. the tagged address ABI. Untag the user addresses on entry to these functions. Signed-off-by: Catalin Marinas --- mm/mmap.c | 5 +++++ mm/mremap.c | 6 +----- 2 files changed, 6 insertions(+), 5 deletions(-) diff --git a/mm/mmap.c b/mm/mmap.c index 7e8c3e8ae75f..b766b633b7ae 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -201,6 +201,8 @@ SYSCALL_DEFINE1(brk, unsigned long, brk) bool downgraded = false; LIST_HEAD(uf); + brk = untagged_addr(brk); + if (down_write_killable(&mm->mmap_sem)) return -EINTR; @@ -1573,6 +1575,8 @@ unsigned long ksys_mmap_pgoff(unsigned long addr, unsigned long len, struct file *file = NULL; unsigned long retval; + addr = untagged_addr(addr); + if (!(flags & MAP_ANONYMOUS)) { audit_mmap_fd(fd, flags); file = fget(fd); @@ -2874,6 +2878,7 @@ EXPORT_SYMBOL(vm_munmap); SYSCALL_DEFINE2(munmap, unsigned long, addr, size_t, len) { + addr = untagged_addr(addr); profile_munmap(addr); return __vm_munmap(addr, len, true); } diff --git a/mm/mremap.c b/mm/mremap.c index 64c9a3b8be0a..1fc8a29fbe3f 100644 --- a/mm/mremap.c +++ b/mm/mremap.c @@ -606,12 +606,8 @@ SYSCALL_DEFINE5(mremap, unsigned long, addr, unsigned long, old_len, LIST_HEAD(uf_unmap_early); LIST_HEAD(uf_unmap); - /* - * Architectures may interpret the tag passed to mmap as a background - * colour for the corresponding vma. For mremap we don't allow tagged - * new_addr to preserve similar behaviour to mmap. - */ addr = untagged_addr(addr); + new_addr = untagged_addr(new_addr); if (flags & ~(MREMAP_FIXED | MREMAP_MAYMOVE)) return ret;