From patchwork Tue Nov 13 13:07:22 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nadav Amit X-Patchwork-Id: 10681491 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 9E27014D6 for ; Tue, 13 Nov 2018 20:26:21 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 8D9A62B640 for ; Tue, 13 Nov 2018 20:26:21 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 7ED2C2B657; Tue, 13 Nov 2018 20:26:21 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.4 required=2.0 tests=BAYES_00,DATE_IN_PAST_06_12, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 1EF642B640 for ; Tue, 13 Nov 2018 20:26:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725813AbeKNGZ1 (ORCPT ); Wed, 14 Nov 2018 01:25:27 -0500 Received: from ex13-edg-ou-001.vmware.com ([208.91.0.189]:21360 "EHLO EX13-EDG-OU-001.vmware.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725892AbeKNGZ0 (ORCPT ); Wed, 14 Nov 2018 01:25:26 -0500 Received: from sc9-mailhost2.vmware.com (10.113.161.72) by EX13-EDG-OU-001.vmware.com (10.113.208.155) with Microsoft SMTP Server id 15.0.1156.6; Tue, 13 Nov 2018 12:25:11 -0800 Received: from sc2-haas01-esx0118.eng.vmware.com (sc2-haas01-esx0118.eng.vmware.com [10.172.44.118]) by sc9-mailhost2.vmware.com (Postfix) with ESMTP id 8DB64B1A5A; Tue, 13 Nov 2018 15:25:38 -0500 (EST) From: Nadav Amit To: Ingo Molnar CC: , , "H. Peter Anvin" , Thomas Gleixner , Borislav Petkov , Dave Hansen , Peter Zijlstra , , , , Nadav Amit , Andy Lutomirski , Kees Cook , Dave Hansen , Masami Hiramatsu Subject: [PATCH v5 02/10] x86/jump_label: Use text_poke_early() during early init Date: Tue, 13 Nov 2018 05:07:22 -0800 Message-ID: <20181113130730.44844-3-namit@vmware.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20181113130730.44844-1-namit@vmware.com> References: <20181113130730.44844-1-namit@vmware.com> MIME-Version: 1.0 Received-SPF: None (EX13-EDG-OU-001.vmware.com: namit@vmware.com does not designate permitted sender hosts) Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: X-Virus-Scanned: ClamAV using ClamSMTP There is no apparent reason not to use text_poke_early() while we are during early-init and we do not patch code that might be on the stack (i.e., we'll return to the middle of the patched code). This appears to be the case of jump-labels, so do so. This is required for the next patches that would set a temporary mm for patching, which is initialized after some static-keys are enabled/disabled. Cc: Andy Lutomirski Cc: Kees Cook Cc: Dave Hansen Cc: Masami Hiramatsu Co-Developed-by: Peter Zijlstra Signed-off-by: Nadav Amit --- arch/x86/kernel/jump_label.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/arch/x86/kernel/jump_label.c b/arch/x86/kernel/jump_label.c index aac0c1f7e354..ed5fe274a7d8 100644 --- a/arch/x86/kernel/jump_label.c +++ b/arch/x86/kernel/jump_label.c @@ -52,7 +52,12 @@ static void __ref __jump_label_transform(struct jump_entry *entry, jmp.offset = jump_entry_target(entry) - (jump_entry_code(entry) + JUMP_LABEL_NOP_SIZE); - if (early_boot_irqs_disabled) + /* + * As long as we're UP and not yet marked RO, we can use + * text_poke_early; SYSTEM_BOOTING guarantees both, as we switch to + * SYSTEM_SCHEDULING before going either. + */ + if (system_state == SYSTEM_BOOTING) poker = text_poke_early; if (type == JUMP_LABEL_JMP) {