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 B1C3BC43610 for ; Sun, 11 Nov 2018 06:35:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 863802154B for ; Sun, 11 Nov 2018 06:35:32 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 863802154B 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-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728022AbeKKQXK (ORCPT ); Sun, 11 Nov 2018 11:23:10 -0500 Received: from ex13-edg-ou-001.vmware.com ([208.91.0.189]:25452 "EHLO EX13-EDG-OU-001.vmware.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727648AbeKKQXJ (ORCPT ); Sun, 11 Nov 2018 11:23:09 -0500 Received: from sc9-mailhost3.vmware.com (10.113.161.73) by EX13-EDG-OU-001.vmware.com (10.113.208.155) with Microsoft SMTP Server id 15.0.1156.6; Sat, 10 Nov 2018 22:35:01 -0800 Received: from sc2-haas01-esx0118.eng.vmware.com (sc2-haas01-esx0118.eng.vmware.com [10.172.44.118]) by sc9-mailhost3.vmware.com (Postfix) with ESMTP id 8DA4640762; Sat, 10 Nov 2018 22:35:24 -0800 (PST) From: Nadav Amit To: Ingo Molnar CC: , , "H. Peter Anvin" , Thomas Gleixner , Borislav Petkov , Dave Hansen , Nadav Amit , Andy Lutomirski , Kees Cook , Peter Zijlstra , Dave Hansen , Masami Hiramatsu Subject: [PATCH v4 09/10] x86/jump-label: remove support for custom poker Date: Sat, 10 Nov 2018 15:17:31 -0800 Message-ID: <20181110231732.15060-10-namit@vmware.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20181110231732.15060-1-namit@vmware.com> References: <20181110231732.15060-1-namit@vmware.com> MIME-Version: 1.0 Content-Type: text/plain Received-SPF: None (EX13-EDG-OU-001.vmware.com: namit@vmware.com does not designate permitted sender hosts) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org There are only two types of poking: early and breakpoint based. The use of a function pointer to perform poking complicates the code and is probably inefficient due to the use of indirect branches. Cc: Andy Lutomirski Cc: Kees Cook Cc: Peter Zijlstra Cc: Dave Hansen Cc: Masami Hiramatsu Signed-off-by: Nadav Amit --- arch/x86/kernel/jump_label.c | 17 +++++++---------- 1 file changed, 7 insertions(+), 10 deletions(-) diff --git a/arch/x86/kernel/jump_label.c b/arch/x86/kernel/jump_label.c index ed5fe274a7d8..7947df599e58 100644 --- a/arch/x86/kernel/jump_label.c +++ b/arch/x86/kernel/jump_label.c @@ -39,13 +39,13 @@ static void bug_at(unsigned char *ip, int line) static void __ref __jump_label_transform(struct jump_entry *entry, enum jump_label_type type, - void *(*poker)(void *, const void *, size_t), int init) { union jump_code_union jmp; const unsigned char default_nop[] = { STATIC_KEY_INIT_NOP }; const unsigned char *ideal_nop = ideal_nops[NOP_ATOMIC5]; const void *expect, *code; + bool early_poking = init; int line; jmp.jump = 0xe9; @@ -58,7 +58,7 @@ static void __ref __jump_label_transform(struct jump_entry *entry, * SYSTEM_SCHEDULING before going either. */ if (system_state == SYSTEM_BOOTING) - poker = text_poke_early; + early_poking = true; if (type == JUMP_LABEL_JMP) { if (init) { @@ -82,16 +82,13 @@ static void __ref __jump_label_transform(struct jump_entry *entry, bug_at((void *)jump_entry_code(entry), line); /* - * Make text_poke_bp() a default fallback poker. - * * At the time the change is being done, just ignore whether we * are doing nop -> jump or jump -> nop transition, and assume * always nop being the 'currently valid' instruction - * */ - if (poker) { - (*poker)((void *)jump_entry_code(entry), code, - JUMP_LABEL_NOP_SIZE); + if (early_poking) { + text_poke_early((void *)jump_entry_code(entry), code, + JUMP_LABEL_NOP_SIZE); return; } @@ -103,7 +100,7 @@ void arch_jump_label_transform(struct jump_entry *entry, enum jump_label_type type) { mutex_lock(&text_mutex); - __jump_label_transform(entry, type, NULL, 0); + __jump_label_transform(entry, type, 0); mutex_unlock(&text_mutex); } @@ -133,7 +130,7 @@ __init_or_module void arch_jump_label_transform_static(struct jump_entry *entry, jlstate = JL_STATE_NO_UPDATE; } if (jlstate == JL_STATE_UPDATE) - __jump_label_transform(entry, type, text_poke_early, 1); + __jump_label_transform(entry, type, 1); } #endif -- 2.17.1