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=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, 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 D4B65C433FF for ; Mon, 5 Aug 2019 21:21:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AA72520B1F for ; Mon, 5 Aug 2019 21:21:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730640AbfHEVVh (ORCPT ); Mon, 5 Aug 2019 17:21:37 -0400 Received: from mga12.intel.com ([192.55.52.136]:62828 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730055AbfHEVVh (ORCPT ); Mon, 5 Aug 2019 17:21:37 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga106.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 05 Aug 2019 14:21:36 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.64,350,1559545200"; d="scan'208";a="192503883" Received: from sjchrist-coffee.jf.intel.com ([10.54.74.41]) by fmsmga001.fm.intel.com with ESMTP; 05 Aug 2019 14:21:36 -0700 From: Sean Christopherson To: Thomas Gleixner , Ingo Molnar , Borislav Petkov , x86@kernel.org Cc: "H. Peter Anvin" , linux-kernel@vger.kernel.org Subject: [PATCH] x86/apic: Annotate global config variables as "read-only after init" Date: Mon, 5 Aug 2019 14:21:34 -0700 Message-Id: <20190805212134.12001-1-sean.j.christopherson@intel.com> X-Mailer: git-send-email 2.22.0 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Mark the APIC's global config variables that are constant after boot as __ro_after_init to help document that the majority of the APIC config is not changed at runtime, and to harden the kernel a smidge. Signed-off-by: Sean Christopherson --- This applies on tip/x86/apic, which is currently: 43931d350f30 ("x86/apic/x2apic: Implement IPI shorthands support") Let me know if this patch should be based on a different tree. arch/x86/kernel/apic/apic.c | 26 +++++++++++++------------- 1 file changed, 13 insertions(+), 13 deletions(-) diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c index 831274e3c09f..3a31875bd0a3 100644 --- a/arch/x86/kernel/apic/apic.c +++ b/arch/x86/kernel/apic/apic.c @@ -65,10 +65,10 @@ unsigned int num_processors; unsigned disabled_cpus; /* Processor that is doing the boot up */ -unsigned int boot_cpu_physical_apicid = -1U; +unsigned int boot_cpu_physical_apicid __ro_after_init = -1U; EXPORT_SYMBOL_GPL(boot_cpu_physical_apicid); -u8 boot_cpu_apic_version; +u8 boot_cpu_apic_version __ro_after_init; /* * The highest APIC ID seen during enumeration. @@ -85,13 +85,13 @@ physid_mask_t phys_cpu_present_map; * disable_cpu_apicid=, mostly used for the kdump 2nd kernel to * avoid undefined behaviour caused by sending INIT from AP to BSP. */ -static unsigned int disabled_cpu_apicid __read_mostly = BAD_APICID; +static unsigned int disabled_cpu_apicid __ro_after_init = BAD_APICID; /* * This variable controls which CPUs receive external NMIs. By default, * external NMIs are delivered only to the BSP. */ -static int apic_extnmi = APIC_EXTNMI_BSP; +static int apic_extnmi __ro_after_init = APIC_EXTNMI_BSP; /* * Map cpu index to physical APIC ID @@ -114,7 +114,7 @@ EXPORT_EARLY_PER_CPU_SYMBOL(x86_cpu_to_acpiid); DEFINE_EARLY_PER_CPU_READ_MOSTLY(int, x86_cpu_to_logical_apicid, BAD_APICID); /* Local APIC was disabled by the BIOS and enabled by the kernel */ -static int enabled_via_apicbase; +static int enabled_via_apicbase __ro_after_init; /* * Handle interrupt mode configuration register (IMCR). @@ -172,23 +172,23 @@ static __init int setup_apicpmtimer(char *s) __setup("apicpmtimer", setup_apicpmtimer); #endif -unsigned long mp_lapic_addr; -int disable_apic; +unsigned long mp_lapic_addr __ro_after_init; +int disable_apic __ro_after_init; /* Disable local APIC timer from the kernel commandline or via dmi quirk */ static int disable_apic_timer __initdata; /* Local APIC timer works in C2 */ -int local_apic_timer_c2_ok; +int local_apic_timer_c2_ok __ro_after_init; EXPORT_SYMBOL_GPL(local_apic_timer_c2_ok); /* * Debug level, exported for io_apic.c */ -int apic_verbosity; +int apic_verbosity __ro_after_init; -int pic_mode; +int pic_mode __ro_after_init; /* Have we found an MP table */ -int smp_found_config; +int smp_found_config __ro_after_init; static struct resource lapic_resource = { .name = "Local APIC", @@ -199,7 +199,7 @@ unsigned int lapic_timer_period = 0; static void apic_pm_activate(void); -static unsigned long apic_phys; +static unsigned long apic_phys __ro_after_init; /* * Get the LAPIC version @@ -1278,7 +1278,7 @@ void __init sync_Arb_IDs(void) APIC_INT_LEVELTRIG | APIC_DM_INIT); } -enum apic_intr_mode_id apic_intr_mode; +enum apic_intr_mode_id apic_intr_mode __ro_after_init; static int __init apic_intr_mode_select(void) { -- 2.22.0