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 C8C94C49361 for ; Fri, 18 Jun 2021 15:21:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AE07660FE9 for ; Fri, 18 Jun 2021 15:21:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232387AbhFRPX4 (ORCPT ); Fri, 18 Jun 2021 11:23:56 -0400 Received: from Galois.linutronix.de ([193.142.43.55]:56806 "EHLO galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235101AbhFRPWT (ORCPT ); Fri, 18 Jun 2021 11:22:19 -0400 Message-Id: <20210618143449.052887078@linutronix.de> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1624029609; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: references:references; bh=itrlsLN5HOKM48WUxZ1pfjo8yfvFp7TBRKSjY4/yY5U=; b=snR1SsRDTTBvgELE7Qd+Hu7PnOzBxtIEHzBPHeGsVneDmvd+MyedB4glPNip0rIv13P8c+ zbj9kkoaDssAmTwQM/Yki+UJy44ZrJTsx8t0YcyIT71kCPHjYALlwfRhS85vHZStPfDdYN SnqMr9eRwLbohEjs/8XiYSEg2K480AbCKtARbd2jLJI+Iq1w7AkCXBfFY2f3fBhlgCG3vc wUeJoDRZRoFfMTwk5RRUKkTEZ2bV3UE5aOtQ6MoUkfJvWHzdRX9h5wQlQUsLc17UkcpAgx 7z3oJXUD/f947BHxneodAjDO6foJnZ86Zekv9MI2QrlK7H9QIvBXUtJY0hvtSQ== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1624029609; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: references:references; bh=itrlsLN5HOKM48WUxZ1pfjo8yfvFp7TBRKSjY4/yY5U=; b=88E1W/piaRRHQZhSDDZEjaNYZpgGHh61WdBaZqh1TJ+S1l6fBx+Dxksgj01Hc2aZL+EKEl N6XPlaB42N6ZnFAA== Date: Fri, 18 Jun 2021 16:19:04 +0200 From: Thomas Gleixner To: LKML Cc: Andy Lutomirski , Dave Hansen , Fenghua Yu , Tony Luck , Yu-cheng Yu , Sebastian Andrzej Siewior , Borislav Petkov , Peter Zijlstra , Kan Liang Subject: [patch V3 41/66] x86/cpu: Sanitize X86_FEATURE_OSPKE References: <20210618141823.161158090@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-transfer-encoding: 8-bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X86_FEATURE_OSPKE is enabled first on the boot CPU and the feature flag is set. Secondary CPUs have to enable CR4.PKE as well and set their per CPU feature flag. That's ineffective because all call sites have checks for boot_cpu_data. Make it smarter and force the feature flag when PKU is enabled on the boot cpu which allows then to use cpu_feature_enabled(X86_FEATURE_OSPKE) all over the place. That either compiles the code out when PKEY support is disabled in Kconfig or uses a static_cpu_has() for the feature check which makes a significant difference in hotpathes, e.g. context switch. Signed-off-by: Thomas Gleixner --- arch/x86/include/asm/pkeys.h | 8 ++++---- arch/x86/include/asm/pkru.h | 4 ++-- arch/x86/kernel/cpu/common.c | 24 +++++++++++------------- arch/x86/kernel/fpu/core.c | 2 +- arch/x86/kernel/fpu/xstate.c | 2 +- arch/x86/kernel/process_64.c | 2 +- arch/x86/mm/fault.c | 2 +- 7 files changed, 21 insertions(+), 23 deletions(-) --- a/arch/x86/include/asm/pkeys.h +++ b/arch/x86/include/asm/pkeys.h @@ -9,14 +9,14 @@ * will be necessary to ensure that the types that store key * numbers and masks have sufficient capacity. */ -#define arch_max_pkey() (boot_cpu_has(X86_FEATURE_OSPKE) ? 16 : 1) +#define arch_max_pkey() (cpu_feature_enabled(X86_FEATURE_OSPKE) ? 16 : 1) extern int arch_set_user_pkey_access(struct task_struct *tsk, int pkey, unsigned long init_val); static inline bool arch_pkeys_enabled(void) { - return boot_cpu_has(X86_FEATURE_OSPKE); + return cpu_feature_enabled(X86_FEATURE_OSPKE); } /* @@ -26,7 +26,7 @@ static inline bool arch_pkeys_enabled(vo extern int __execute_only_pkey(struct mm_struct *mm); static inline int execute_only_pkey(struct mm_struct *mm) { - if (!boot_cpu_has(X86_FEATURE_OSPKE)) + if (!cpu_feature_enabled(X86_FEATURE_OSPKE)) return ARCH_DEFAULT_PKEY; return __execute_only_pkey(mm); @@ -37,7 +37,7 @@ extern int __arch_override_mprotect_pkey static inline int arch_override_mprotect_pkey(struct vm_area_struct *vma, int prot, int pkey) { - if (!boot_cpu_has(X86_FEATURE_OSPKE)) + if (!cpu_feature_enabled(X86_FEATURE_OSPKE)) return 0; return __arch_override_mprotect_pkey(vma, prot, pkey); --- a/arch/x86/include/asm/pkru.h +++ b/arch/x86/include/asm/pkru.h @@ -32,7 +32,7 @@ static inline bool __pkru_allows_write(u static inline u32 read_pkru(void) { - if (boot_cpu_has(X86_FEATURE_OSPKE)) + if (cpu_feature_enabled(X86_FEATURE_OSPKE)) return rdpkru(); return 0; } @@ -41,7 +41,7 @@ static inline void write_pkru(u32 pkru) { struct pkru_state *pk; - if (!boot_cpu_has(X86_FEATURE_OSPKE)) + if (!cpu_feature_enabled(X86_FEATURE_OSPKE)) return; pk = get_xsave_addr(¤t->thread.fpu.state.xsave, XFEATURE_PKRU); --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -466,22 +466,20 @@ static bool pku_disabled; static __always_inline void setup_pku(struct cpuinfo_x86 *c) { - /* check the boot processor, plus compile options for PKU: */ - if (!cpu_feature_enabled(X86_FEATURE_PKU)) - return; - /* checks the actual processor's cpuid bits: */ - if (!cpu_has(c, X86_FEATURE_PKU)) - return; - if (pku_disabled) + if (c == &boot_cpu_data) { + if (pku_disabled || !cpu_feature_enabled(X86_FEATURE_PKU)) + return; + /* + * Setting CR4.PKE will cause the X86_FEATURE_OSPKE cpuid + * bit to be set. Enforce it. + */ + setup_force_cpu_cap(X86_FEATURE_OSPKE); + + } else if (!cpu_feature_enabled(X86_FEATURE_OSPKE)) { return; + } cr4_set_bits(X86_CR4_PKE); - /* - * Setting X86_CR4_PKE will cause the X86_FEATURE_OSPKE - * cpuid bit to be set. We need to ensure that we - * update that bit in this CPU's "cpu_info". - */ - set_cpu_cap(c, X86_FEATURE_OSPKE); } #ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS --- a/arch/x86/kernel/fpu/core.c +++ b/arch/x86/kernel/fpu/core.c @@ -311,7 +311,7 @@ static inline void load_fpregs_from_init else frstor(&init_fpstate.fsave); - if (boot_cpu_has(X86_FEATURE_OSPKE)) + if (cpu_feature_enabled(X86_FEATURE_OSPKE)) copy_init_pkru_to_fpregs(); } --- a/arch/x86/kernel/fpu/xstate.c +++ b/arch/x86/kernel/fpu/xstate.c @@ -921,7 +921,7 @@ int arch_set_user_pkey_access(struct tas * This check implies XSAVE support. OSPKE only gets * set if we enable XSAVE and we enable PKU in XCR0. */ - if (!boot_cpu_has(X86_FEATURE_OSPKE)) + if (!cpu_feature_enabled(X86_FEATURE_OSPKE)) return -EINVAL; /* --- a/arch/x86/kernel/process_64.c +++ b/arch/x86/kernel/process_64.c @@ -137,7 +137,7 @@ void __show_regs(struct pt_regs *regs, e log_lvl, d3, d6, d7); } - if (boot_cpu_has(X86_FEATURE_OSPKE)) + if (cpu_feature_enabled(X86_FEATURE_OSPKE)) printk("%sPKRU: %08x\n", log_lvl, read_pkru()); } --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -875,7 +875,7 @@ static inline bool bad_area_access_from_ /* This code is always called on the current mm */ bool foreign = false; - if (!boot_cpu_has(X86_FEATURE_OSPKE)) + if (!cpu_feature_enabled(X86_FEATURE_OSPKE)) return false; if (error_code & X86_PF_PK) return true;