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=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=no 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 3D335C10F27 for ; Fri, 6 Mar 2020 13:09:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1C57124655 for ; Fri, 6 Mar 2020 13:09:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726307AbgCFNIq (ORCPT ); Fri, 6 Mar 2020 08:08:46 -0500 Received: from Galois.linutronix.de ([193.142.43.55]:53327 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726676AbgCFNIq (ORCPT ); Fri, 6 Mar 2020 08:08:46 -0500 Received: from p5de0bf0b.dip0.t-ipconnect.de ([93.224.191.11] helo=nanos.tec.linutronix.de) by Galois.linutronix.de with esmtpsa (TLS1.2:DHE_RSA_AES_256_CBC_SHA256:256) (Exim 4.80) (envelope-from ) id 1jACiV-0003fm-39; Fri, 06 Mar 2020 14:08:39 +0100 Received: from nanos.tec.linutronix.de (localhost [IPv6:::1]) by nanos.tec.linutronix.de (Postfix) with ESMTP id 7C7E2104097; Fri, 6 Mar 2020 14:08:38 +0100 (CET) Message-Id: <20200306130623.590923677@linutronix.de> User-Agent: quilt/0.65 Date: Fri, 06 Mar 2020 14:03:43 +0100 From: Thomas Gleixner To: LKML Cc: Marc Zyngier , x86@kernel.org, Bjorn Helgaas , linux-pci@vger.kernel.org, Keith Busch , Kuppuswamy Sathyanarayanan Subject: [patch 2/7] genirq: Add protection against unsafe usage of generic_handle_irq() References: <20200306130341.199467200@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org In general calling generic_handle_irq() with interrupts disabled from non interrupt context is harmless. For some interrupt controllers like the x86 trainwrecks this is outright dangerous as it might corrupt state if an interrupt affinity change is pending. Add infrastructure which allows to mark interrupts as unsafe and catch such usage in generic_handle_irq(). Reported-by: sathyanarayanan.kuppuswamy@linux.intel.com Signed-off-by: Thomas Gleixner --- include/linux/irq.h | 13 +++++++++++++ kernel/irq/internals.h | 8 ++++++++ kernel/irq/irqdesc.c | 6 ++++++ kernel/irq/resend.c | 5 +++-- 4 files changed, 30 insertions(+), 2 deletions(-) --- a/include/linux/irq.h +++ b/include/linux/irq.h @@ -211,6 +211,8 @@ struct irq_data { * IRQD_CAN_RESERVE - Can use reservation mode * IRQD_MSI_NOMASK_QUIRK - Non-maskable MSI quirk for affinity change * required + * IRQD_HANDLE_ENFORCE_IRQCTX - Enforce that handle_irq_*() is only invoked + * from actual interrupt context. */ enum { IRQD_TRIGGER_MASK = 0xf, @@ -234,6 +236,7 @@ enum { IRQD_DEFAULT_TRIGGER_SET = (1 << 25), IRQD_CAN_RESERVE = (1 << 26), IRQD_MSI_NOMASK_QUIRK = (1 << 27), + IRQD_HANDLE_ENFORCE_IRQCTX = (1 << 28), }; #define __irqd_to_state(d) ACCESS_PRIVATE((d)->common, state_use_accessors) @@ -303,6 +306,16 @@ static inline bool irqd_is_single_target return __irqd_to_state(d) & IRQD_SINGLE_TARGET; } +static inline void irqd_set_handle_enforce_irqctx(struct irq_data *d) +{ + __irqd_to_state(d) |= IRQD_HANDLE_ENFORCE_IRQCTX; +} + +static inline bool irqd_is_handle_enforce_irqctx(struct irq_data *d) +{ + return __irqd_to_state(d) & IRQD_HANDLE_ENFORCE_IRQCTX; +} + static inline bool irqd_is_wakeup_set(struct irq_data *d) { return __irqd_to_state(d) & IRQD_WAKEUP_STATE; --- a/kernel/irq/internals.h +++ b/kernel/irq/internals.h @@ -425,6 +425,10 @@ static inline struct cpumask *irq_desc_g { return desc->pending_mask; } +static inline bool handle_enforce_irqctx(struct irq_data *data) +{ + return irqd_is_handle_enforce_irqctx(data); +} bool irq_fixup_move_pending(struct irq_desc *desc, bool force_clear); #else /* CONFIG_GENERIC_PENDING_IRQ */ static inline bool irq_can_move_pcntxt(struct irq_data *data) @@ -451,6 +455,10 @@ static inline bool irq_fixup_move_pendin { return false; } +static inline bool handle_enforce_irqctx(struct irq_data *data) +{ + return false; +} #endif /* !CONFIG_GENERIC_PENDING_IRQ */ #if !defined(CONFIG_IRQ_DOMAIN) || !defined(CONFIG_IRQ_DOMAIN_HIERARCHY) --- a/kernel/irq/irqdesc.c +++ b/kernel/irq/irqdesc.c @@ -638,9 +638,15 @@ void irq_init_desc(unsigned int irq) int generic_handle_irq(unsigned int irq) { struct irq_desc *desc = irq_to_desc(irq); + struct irq_data *data; if (!desc) return -EINVAL; + + data = irq_desc_get_irq_data(desc); + if (WARN_ON_ONCE(!in_irq() && handle_enforce_irqctx(data))) + return -EPERM; + generic_handle_irq_desc(desc); return 0; } --- a/kernel/irq/resend.c +++ b/kernel/irq/resend.c @@ -72,8 +72,9 @@ void check_irq_resend(struct irq_desc *d desc->istate &= ~IRQS_PENDING; desc->istate |= IRQS_REPLAY; - if (!desc->irq_data.chip->irq_retrigger || - !desc->irq_data.chip->irq_retrigger(&desc->irq_data)) { + if ((!desc->irq_data.chip->irq_retrigger || + !desc->irq_data.chip->irq_retrigger(&desc->irq_data)) && + !handle_enforce_irqctx(&desc->irq_data)) { #ifdef CONFIG_HARDIRQS_SW_RESEND unsigned int irq = irq_desc_get_irq(desc);