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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 4D2FBC433ED for ; Thu, 6 May 2021 19:44:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2F320613BA for ; Thu, 6 May 2021 19:44:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235717AbhEFTpP (ORCPT ); Thu, 6 May 2021 15:45:15 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33566 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235740AbhEFTox (ORCPT ); Thu, 6 May 2021 15:44:53 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1E7E1C06138D for ; Thu, 6 May 2021 12:43:55 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=Content-Type:MIME-Version:References: Subject:Cc:To:From:Date:Message-ID:Sender:Reply-To:Content-Transfer-Encoding: Content-ID:Content-Description:In-Reply-To; bh=hkvQMeUwV3lUUZcHckLdVsZKUO+Em/Rb7jbt+jRJULk=; b=qHh1CFEY5Egi+5dlDfqjtG8qnh e/E4EDMvesLbzbdOP0+edu/8Z2Mczm1iDDAhSlvEIBqnjfnv1qkv7XpXvk8ksws+nwhyIkidseBPX /i6g+RLjkI55PcX00sVTzih1PGaI1JtiyALRoOGanfRwWqXqsGtjg3b50Qi49hRZ3isaHI/TvCnlw 8f9S4zgwkZTenV8+zWtG82yQ9zhdpuMgHE3abJpSraAKgCiD6i1hmO4YRftUJsByLu2FghlyI1ktd PDO8HSwradtzmIZhPnyBi+wuNP9Fx17GKRG39bmJvtVLjDcVT5O5LSMS9qcky8/sxrGO49Nr0eTFH rmlPdU1w==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.94 #2 (Red Hat Linux)) id 1lejtS-002ADE-Cm; Thu, 06 May 2021 19:42:48 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 18A29300356; Thu, 6 May 2021 21:42:39 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 0) id B1F2320B96F8B; Thu, 6 May 2021 21:42:38 +0200 (CEST) Message-ID: <20210506194157.786777050@infradead.org> User-Agent: quilt/0.66 Date: Thu, 06 May 2021 21:33:58 +0200 From: Peter Zijlstra To: x86@kernel.org, jpoimboe@redhat.com, jbaron@akamai.com, rostedt@goodmis.org, ardb@kernel.org Cc: linux-kernel@vger.kernel.org, peterz@infradead.org Subject: [PATCH 06/13] jump_label, x86: Introduce jump_entry_size() References: <20210506193352.719596001@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This allows architectures to have variable sized jumps. Signed-off-by: Peter Zijlstra (Intel) --- arch/x86/include/asm/jump_label.h | 4 ++-- arch/x86/kernel/jump_label.c | 7 +++++++ include/linux/jump_label.h | 9 +++++++++ kernel/jump_label.c | 2 +- 4 files changed, 19 insertions(+), 3 deletions(-) --- a/arch/x86/include/asm/jump_label.h +++ b/arch/x86/include/asm/jump_label.h @@ -4,8 +4,6 @@ #define HAVE_JUMP_LABEL_BATCH -#define JUMP_LABEL_NOP_SIZE 5 - #include #include @@ -47,6 +45,8 @@ static __always_inline bool arch_static_ return true; } +extern int arch_jump_entry_size(struct jump_entry *entry); + #endif /* __ASSEMBLY__ */ #endif --- a/arch/x86/kernel/jump_label.c +++ b/arch/x86/kernel/jump_label.c @@ -16,6 +16,13 @@ #include #include +#define JUMP_LABEL_NOP_SIZE JMP32_INSN_SIZE + +int arch_jump_entry_size(struct jump_entry *entry) +{ + return JMP32_INSN_SIZE; +} + static const void * __jump_label_set_jump_code(struct jump_entry *entry, enum jump_label_type type) { --- a/include/linux/jump_label.h +++ b/include/linux/jump_label.h @@ -176,6 +176,15 @@ static inline void jump_entry_set_init(s entry->key |= 2; } +static inline int jump_entry_size(struct jump_entry *entry) +{ +#ifdef JUMP_LABEL_NOP_SIZE + return JUMP_LABEL_NOP_SIZE; +#else + return arch_jump_entry_size(entry); +#endif +} + #endif #endif --- a/kernel/jump_label.c +++ b/kernel/jump_label.c @@ -309,7 +309,7 @@ EXPORT_SYMBOL_GPL(jump_label_rate_limit) static int addr_conflict(struct jump_entry *entry, void *start, void *end) { if (jump_entry_code(entry) <= (unsigned long)end && - jump_entry_code(entry) + JUMP_LABEL_NOP_SIZE > (unsigned long)start) + jump_entry_code(entry) + jump_entry_size(entry) > (unsigned long)start) return 1; return 0;