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=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,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 D8705C04AAF for ; Thu, 16 May 2019 16:05:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B54A720815 for ; Thu, 16 May 2019 16:05:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726987AbfEPQE5 (ORCPT ); Thu, 16 May 2019 12:04:57 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:42426 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726666AbfEPP6l (ORCPT ); Thu, 16 May 2019 11:58:41 -0400 Received: from [167.98.27.226] (helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1hRImD-0006zA-SW; Thu, 16 May 2019 16:58:37 +0100 Received: from ben by deadeye with local (Exim 4.92) (envelope-from ) id 1hRImD-0001O5-3H; Thu, 16 May 2019 16:58:37 +0100 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, Denis Kirjanov , "H. Peter Anvin" , "Brian Gerst" , "Frederic Weisbecker" , "Linus Torvalds" , "Andy Lutomirski" , "Andy Lutomirski" , "Denys Vlasenko" , "Ingo Molnar" , "Thomas Gleixner" , "Borislav Petkov" , "Peter Zijlstra" Date: Thu, 16 May 2019 16:55:33 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) X-Patchwork-Hint: ignore Subject: [PATCH 3.16 22/86] x86/asm: Add asm macros for static keys/jump labels In-Reply-To: X-SA-Exim-Connect-IP: 167.98.27.226 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.68-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Andy Lutomirski commit 2671c3e4fe2a34bd9bf2eecdf5d1149d4b55dbdf upstream. Unfortunately, we can only do this if HAVE_JUMP_LABEL. In principle, we could do some serious surgery on the core jump label infrastructure to keep the patch infrastructure available on x86 on all builds, but that's probably not worth it. Implementing the macros using a conditional branch as a fallback seems like a bad idea: we'd have to clobber flags. This limitation can't cause silent failures -- trying to include asm/jump_label.h at all on a non-HAVE_JUMP_LABEL kernel will error out. The macro's users are responsible for handling this issue themselves. Signed-off-by: Andy Lutomirski Reviewed-by: Thomas Gleixner Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Denys Vlasenko Cc: Frederic Weisbecker Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/63aa45c4b692e8469e1876d6ccbb5da707972990.1447361906.git.luto@kernel.org Signed-off-by: Ingo Molnar Signed-off-by: Ben Hutchings --- arch/x86/include/asm/jump_label.h | 52 ++++++++++++++++++++++++++----- 1 file changed, 44 insertions(+), 8 deletions(-) --- a/arch/x86/include/asm/jump_label.h +++ b/arch/x86/include/asm/jump_label.h @@ -14,13 +14,6 @@ #error asm/jump_label.h included on a non-jump-label kernel #endif -#ifndef __ASSEMBLY__ - -#include -#include -#include -#include - #define JUMP_LABEL_NOP_SIZE 5 #ifdef CONFIG_X86_64 @@ -29,6 +22,14 @@ # define STATIC_KEY_INIT_NOP GENERIC_NOP5_ATOMIC #endif +#include +#include + +#ifndef __ASSEMBLY__ + +#include +#include + static __always_inline bool arch_static_branch(struct static_key *key, bool branch) { asm_volatile_goto("1:" @@ -72,5 +73,40 @@ struct jump_entry { jump_label_t key; }; -#endif /* __ASSEMBLY__ */ +#else /* __ASSEMBLY__ */ + +.macro STATIC_JUMP_IF_TRUE target, key, def +.Lstatic_jump_\@: + .if \def + /* Equivalent to "jmp.d32 \target" */ + .byte 0xe9 + .long \target - .Lstatic_jump_after_\@ +.Lstatic_jump_after_\@: + .else + .byte STATIC_KEY_INIT_NOP + .endif + .pushsection __jump_table, "aw" + _ASM_ALIGN + _ASM_PTR .Lstatic_jump_\@, \target, \key + .popsection +.endm + +.macro STATIC_JUMP_IF_FALSE target, key, def +.Lstatic_jump_\@: + .if \def + .byte STATIC_KEY_INIT_NOP + .else + /* Equivalent to "jmp.d32 \target" */ + .byte 0xe9 + .long \target - .Lstatic_jump_after_\@ +.Lstatic_jump_after_\@: + .endif + .pushsection __jump_table, "aw" + _ASM_ALIGN + _ASM_PTR .Lstatic_jump_\@, \target, \key + 1 + .popsection +.endm + +#endif /* __ASSEMBLY__ */ + #endif