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=-9.0 required=3.0 tests=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 6ABC8C282DD for ; Thu, 23 May 2019 10:24:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3F6F5217D4 for ; Thu, 23 May 2019 10:24:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730508AbfEWKYh (ORCPT ); Thu, 23 May 2019 06:24:37 -0400 Received: from foss.arm.com ([217.140.101.70]:42688 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727434AbfEWKYg (ORCPT ); Thu, 23 May 2019 06:24:36 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 15B3BA78; Thu, 23 May 2019 03:24:36 -0700 (PDT) Received: from e111045-lin.cambridge.arm.com (unknown [10.1.39.23]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id E8F623F718; Thu, 23 May 2019 03:24:33 -0700 (PDT) From: Ard Biesheuvel To: linux-arm-kernel@lists.infradead.org Cc: marc.zyngier@arm.com, mark.rutland@arm.com, linux-kernel@vger.kernel.org, Ard Biesheuvel , Nadav Amit , Rick Edgecombe , Peter Zijlstra , Andrew Morton , Will Deacon , Masami Hiramatsu , James Morse Subject: [PATCH 3/4] arm64/kprobes: set VM_FLUSH_RESET_PERMS on kprobe instruction pages Date: Thu, 23 May 2019 11:22:55 +0100 Message-Id: <20190523102256.29168-4-ard.biesheuvel@arm.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190523102256.29168-1-ard.biesheuvel@arm.com> References: <20190523102256.29168-1-ard.biesheuvel@arm.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org In order to avoid transient inconsistencies where freed code pages are remapped writable while stale TLB entries still exist on other cores, mark the kprobes text pages with the VM_FLUSH_RESET_PERMS attribute. This instructs the core vmalloc code not to defer the TLB flush when this region is unmapped and returned to the page allocator. Signed-off-by: Ard Biesheuvel --- arch/arm64/kernel/probes/kprobes.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/arch/arm64/kernel/probes/kprobes.c b/arch/arm64/kernel/probes/kprobes.c index 2509fcb6d404..036cfbf9682a 100644 --- a/arch/arm64/kernel/probes/kprobes.c +++ b/arch/arm64/kernel/probes/kprobes.c @@ -131,8 +131,10 @@ void *alloc_insn_page(void) void *page; page = vmalloc_exec(PAGE_SIZE); - if (page) + if (page) { set_memory_ro((unsigned long)page, 1); + set_vm_flush_reset_perms(page); + } return page; } -- 2.17.1