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=-7.9 required=3.0 tests=DATE_IN_PAST_06_12, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,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 15B6FC04EBA for ; Wed, 21 Nov 2018 03:53:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D4A172145D for ; Wed, 21 Nov 2018 03:53:33 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D4A172145D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=vmware.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-security-module-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727586AbeKUO0J (ORCPT ); Wed, 21 Nov 2018 09:26:09 -0500 Received: from ex13-edg-ou-002.vmware.com ([208.91.0.190]:2110 "EHLO EX13-EDG-OU-002.vmware.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726849AbeKUO0J (ORCPT ); Wed, 21 Nov 2018 09:26:09 -0500 Received: from sc9-mailhost2.vmware.com (10.113.161.72) by EX13-EDG-OU-002.vmware.com (10.113.208.156) with Microsoft SMTP Server id 15.0.1156.6; Tue, 20 Nov 2018 19:52:59 -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 429FAB1874; Tue, 20 Nov 2018 22:53:30 -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 v6 02/10] x86/jump_label: Use text_poke_early() during early init Date: Tue, 20 Nov 2018 12:35:37 -0800 Message-ID: <20181120203545.34928-3-namit@vmware.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20181120203545.34928-1-namit@vmware.com> References: <20181120203545.34928-1-namit@vmware.com> MIME-Version: 1.0 Content-Type: text/plain Received-SPF: None (EX13-EDG-OU-002.vmware.com: namit@vmware.com does not designate permitted sender hosts) Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: 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) { -- 2.17.1