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=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS 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 58FBFC43382 for ; Thu, 27 Sep 2018 16:04:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E70AE216FE for ; Thu, 27 Sep 2018 16:04:37 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E70AE216FE Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=zytor.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 S1728297AbeI0WXc (ORCPT ); Thu, 27 Sep 2018 18:23:32 -0400 Received: from terminus.zytor.com ([198.137.202.136]:56691 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727437AbeI0WXb (ORCPT ); Thu, 27 Sep 2018 18:23:31 -0400 Received: from terminus.zytor.com (localhost [127.0.0.1]) by terminus.zytor.com (8.15.2/8.15.2) with ESMTPS id w8RG3dEQ083588 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Thu, 27 Sep 2018 09:03:39 -0700 Received: (from tipbot@localhost) by terminus.zytor.com (8.15.2/8.15.2/Submit) id w8RG3dwU083585; Thu, 27 Sep 2018 09:03:39 -0700 Date: Thu, 27 Sep 2018 09:03:39 -0700 X-Authentication-Warning: terminus.zytor.com: tipbot set sender to tipbot@zytor.com using -f From: tip-bot for Ard Biesheuvel Message-ID: Cc: heiko.carstens@de.ibm.com, ard.biesheuvel@linaro.org, peterz@infradead.org, linux-kernel@vger.kernel.org, tglx@linutronix.de, rostedt@goodmis.org, jeyu@kernel.org, keescook@chromium.org, catalin.marinas@arm.com, schwidefsky@de.ibm.com, arnd@arndb.de, will.deacon@arm.com, mingo@kernel.org, hpa@zytor.com Reply-To: linux-kernel@vger.kernel.org, tglx@linutronix.de, rostedt@goodmis.org, heiko.carstens@de.ibm.com, peterz@infradead.org, ard.biesheuvel@linaro.org, catalin.marinas@arm.com, schwidefsky@de.ibm.com, arnd@arndb.de, will.deacon@arm.com, hpa@zytor.com, mingo@kernel.org, jeyu@kernel.org, keescook@chromium.org In-Reply-To: <20180919065144.25010-7-ard.biesheuvel@linaro.org> References: <20180919065144.25010-7-ard.biesheuvel@linaro.org> To: linux-tip-commits@vger.kernel.org Subject: [tip:core/core] x86/jump_table: Use relative references Git-Commit-ID: b34006c4258c9c86597b6b7123d6a9a3513d6cd7 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: b34006c4258c9c86597b6b7123d6a9a3513d6cd7 Gitweb: https://git.kernel.org/tip/b34006c4258c9c86597b6b7123d6a9a3513d6cd7 Author: Ard Biesheuvel AuthorDate: Tue, 18 Sep 2018 23:51:41 -0700 Committer: Thomas Gleixner CommitDate: Thu, 27 Sep 2018 17:56:48 +0200 x86/jump_table: Use relative references Similar to the arm64 case, 64-bit x86 can benefit from using relative references rather than absolute ones when emitting struct jump_entry instances. Not only does this reduce the memory footprint of the entries themselves by 33%, it also removes the need for carrying relocation metadata on relocatable builds (i.e., for KASLR) which saves a fair chunk of .init space as well (although the savings are not as dramatic as on arm64) Signed-off-by: Ard Biesheuvel Signed-off-by: Thomas Gleixner Acked-by: Peter Zijlstra (Intel) Cc: linux-arm-kernel@lists.infradead.org Cc: linux-s390@vger.kernel.org Cc: Arnd Bergmann Cc: Heiko Carstens Cc: Kees Cook Cc: Will Deacon Cc: Catalin Marinas Cc: Steven Rostedt Cc: Martin Schwidefsky Cc: Jessica Yu Link: https://lkml.kernel.org/r/20180919065144.25010-7-ard.biesheuvel@linaro.org --- arch/x86/Kconfig | 1 + arch/x86/include/asm/jump_label.h | 24 ++++++++---------------- tools/objtool/special.c | 4 ++-- 3 files changed, 11 insertions(+), 18 deletions(-) diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 1a0be022f91d..603f374f871d 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -119,6 +119,7 @@ config X86 select HAVE_ARCH_AUDITSYSCALL select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE select HAVE_ARCH_JUMP_LABEL + select HAVE_ARCH_JUMP_LABEL_RELATIVE select HAVE_ARCH_KASAN if X86_64 select HAVE_ARCH_KGDB select HAVE_ARCH_MMAP_RND_BITS if MMU diff --git a/arch/x86/include/asm/jump_label.h b/arch/x86/include/asm/jump_label.h index 8c0de4282659..21efc9d07ed9 100644 --- a/arch/x86/include/asm/jump_label.h +++ b/arch/x86/include/asm/jump_label.h @@ -37,7 +37,8 @@ static __always_inline bool arch_static_branch(struct static_key *key, bool bran ".byte " __stringify(STATIC_KEY_INIT_NOP) "\n\t" ".pushsection __jump_table, \"aw\" \n\t" _ASM_ALIGN "\n\t" - _ASM_PTR "1b, %l[l_yes], %c0 + %c1 \n\t" + ".long 1b - ., %l[l_yes] - . \n\t" + _ASM_PTR "%c0 + %c1 - .\n\t" ".popsection \n\t" : : "i" (key), "i" (branch) : : l_yes); @@ -53,7 +54,8 @@ static __always_inline bool arch_static_branch_jump(struct static_key *key, bool "2:\n\t" ".pushsection __jump_table, \"aw\" \n\t" _ASM_ALIGN "\n\t" - _ASM_PTR "1b, %l[l_yes], %c0 + %c1 \n\t" + ".long 1b - ., %l[l_yes] - . \n\t" + _ASM_PTR "%c0 + %c1 - .\n\t" ".popsection \n\t" : : "i" (key), "i" (branch) : : l_yes); @@ -62,18 +64,6 @@ l_yes: return true; } -#ifdef CONFIG_X86_64 -typedef u64 jump_label_t; -#else -typedef u32 jump_label_t; -#endif - -struct jump_entry { - jump_label_t code; - jump_label_t target; - jump_label_t key; -}; - #else /* __ASSEMBLY__ */ .macro STATIC_JUMP_IF_TRUE target, key, def @@ -88,7 +78,8 @@ struct jump_entry { .endif .pushsection __jump_table, "aw" _ASM_ALIGN - _ASM_PTR .Lstatic_jump_\@, \target, \key + .long .Lstatic_jump_\@ - ., \target - . + _ASM_PTR \key - . .popsection .endm @@ -104,7 +95,8 @@ struct jump_entry { .endif .pushsection __jump_table, "aw" _ASM_ALIGN - _ASM_PTR .Lstatic_jump_\@, \target, \key + 1 + .long .Lstatic_jump_\@ - ., \target - . + _ASM_PTR \key + 1 - . .popsection .endm diff --git a/tools/objtool/special.c b/tools/objtool/special.c index 84f001d52322..50af4e1274b3 100644 --- a/tools/objtool/special.c +++ b/tools/objtool/special.c @@ -30,9 +30,9 @@ #define EX_ORIG_OFFSET 0 #define EX_NEW_OFFSET 4 -#define JUMP_ENTRY_SIZE 24 +#define JUMP_ENTRY_SIZE 16 #define JUMP_ORIG_OFFSET 0 -#define JUMP_NEW_OFFSET 8 +#define JUMP_NEW_OFFSET 4 #define ALT_ENTRY_SIZE 13 #define ALT_ORIG_OFFSET 0