From patchwork Thu May 11 17:53:15 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andre Przywara X-Patchwork-Id: 9722675 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id B547460236 for ; Thu, 11 May 2017 17:54:10 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id B5183286D0 for ; Thu, 11 May 2017 17:54:10 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id A9F99286E6; Thu, 11 May 2017 17:54:10 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.2 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id F2149286D0 for ; Thu, 11 May 2017 17:54:09 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.84_2) (envelope-from ) id 1d8sFQ-0000FY-Bm; Thu, 11 May 2017 17:51:32 +0000 Received: from mail6.bemta6.messagelabs.com ([193.109.254.103]) by lists.xenproject.org with esmtp (Exim 4.84_2) (envelope-from ) id 1d8sFP-0000Em-2M for xen-devel@lists.xenproject.org; Thu, 11 May 2017 17:51:31 +0000 Received: from [193.109.254.147] by server-11.bemta-6.messagelabs.com id FB/0E-03587-2A4A4195; Thu, 11 May 2017 17:51:30 +0000 X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFrrOLMWRWlGSWpSXmKPExsVysyfVTXfhEpF Ig4cbdSy+b5nM5MDocfjDFZYAxijWzLyk/IoE1oz3fR+YC1bZVJx59ouxgXGTfhcjF4eQwGZG iQUHu1ggnOWMEpfftrN1MXJysAnoSuy4+ZoZxBYRCJV4uuA7M0gRs8AaRolzi36CFQkL+Eqsu /WYBcRmEVCVaH86jR3E5hWwklh2fANYs4SAnETD+ftgNqeAtcSS6bPA6oWAanbtPs06gZF7AS PDKkb14tSistQiXXO9pKLM9IyS3MTMHF1DAzO93NTi4sT01JzEpGK95PzcTYxADzMAwQ7GmZf 9DzFKcjApifIyThSJFOJLyk+pzEgszogvKs1JLT7EKMPBoSTBG7kYKCdYlJqeWpGWmQMMNZi0 BAePkgjv5kVAad7igsTc4sx0iNQpRkUpcV4ekD4BkERGaR5cGyy8LzHKSgnzMgIdIsRTkFqUm 1mCKv+KUZyDUUmYdyfIFJ7MvBK46a+AFjMBLe7/IwyyuCQRISXVwDhXbMe0P/MuJGb82aux6N tqL/H5mx/x5kwula7V3rirROD98aglCw5PnGGYzlg5e+sBZr5lsedmTZn1iq3pkBWjsnDojZM r54TuscqU+fqm6bLZ+o8+L9mmrNBxlNTRP2+2Jufj277pTnc9BJP9M2VTn/wOVilZJOwY7/Ld 5sl8NtVLz39EL5NWYinOSDTUYi4qTgQAcrpScGoCAAA= X-Env-Sender: andre.przywara@arm.com X-Msg-Ref: server-8.tower-27.messagelabs.com!1494525089!91388339!1 X-Originating-IP: [217.140.101.70] X-SpamReason: No, hits=0.0 required=7.0 tests= X-StarScan-Received: X-StarScan-Version: 9.4.12; banners=-,-,- X-VirusChecked: Checked Received: (qmail 39726 invoked from network); 11 May 2017 17:51:29 -0000 Received: from foss.arm.com (HELO foss.arm.com) (217.140.101.70) by server-8.tower-27.messagelabs.com with SMTP; 11 May 2017 17:51:29 -0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id D59B91610; Thu, 11 May 2017 10:51:28 -0700 (PDT) Received: from e104803-lin.lan (unknown [10.1.207.46]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id AD1703F4FF; Thu, 11 May 2017 10:51:27 -0700 (PDT) From: Andre Przywara To: Julien Grall , Stefano Stabellini Date: Thu, 11 May 2017 18:53:15 +0100 Message-Id: <20170511175340.8448-4-andre.przywara@arm.com> X-Mailer: git-send-email 2.9.0 In-Reply-To: <20170511175340.8448-1-andre.przywara@arm.com> References: <20170511175340.8448-1-andre.przywara@arm.com> Cc: xen-devel@lists.xenproject.org, Vijaya Kumar K , Vijay Kilari , Shanker Donthineni Subject: [Xen-devel] [PATCH v9 03/28] ARM: GIC: Add checks for NULL pointer pending_irq's X-BeenThere: xen-devel@lists.xen.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: xen-devel-bounces@lists.xen.org Sender: "Xen-devel" X-Virus-Scanned: ClamAV using ClamSMTP For LPIs the struct pending_irq's are dynamically allocated and the pointers will be stored in a radix tree. Since an LPI can be "unmapped" at any time, teach the VGIC how to deal with irq_to_pending() returning a NULL pointer. We just do nothing in this case or clean up the LR if the virtual LPI number was still in an LR. Those are all call sites for irq_to_pending(), as per: "git grep irq_to_pending", and their evaluations: (PROTECTED means: added NULL check and bailing out) xen/arch/arm/gic.c: gic_route_irq_to_guest(): only called for SPIs, added ASSERT() gic_remove_irq_from_guest(): only called for SPIs, added ASSERT() gic_remove_from_queues(): PROTECTED, called within VCPU VGIC lock gic_raise_inflight_irq(): PROTECTED, called under VCPU VGIC lock gic_raise_guest_irq(): PROTECTED, called under VCPU VGIC lock gic_update_one_lr(): PROTECTED, called under VCPU VGIC lock xen/arch/arm/vgic.c: vgic_migrate_irq(): not called for LPIs (virtual IRQs), added ASSERT() arch_move_irqs(): not iterating over LPIs, added ASSERT() vgic_disable_irqs(): not called for LPIs, added ASSERT() vgic_enable_irqs(): not called for LPIs, added ASSERT() vgic_vcpu_inject_irq(): PROTECTED, moved under VCPU VGIC lock xen/include/asm-arm/event.h: local_events_need_delivery_nomask(): only called for a PPI, added ASSERT() xen/include/asm-arm/vgic.h: (prototype) Signed-off-by: Andre Przywara Reviewed-by: Stefano Stabellini --- xen/arch/arm/gic.c | 34 ++++++++++++++++++++++++++++++---- xen/arch/arm/vgic.c | 24 ++++++++++++++++++++++++ xen/include/asm-arm/event.h | 3 +++ 3 files changed, 57 insertions(+), 4 deletions(-) diff --git a/xen/arch/arm/gic.c b/xen/arch/arm/gic.c index dcb1783..46bb306 100644 --- a/xen/arch/arm/gic.c +++ b/xen/arch/arm/gic.c @@ -148,6 +148,7 @@ int gic_route_irq_to_guest(struct domain *d, unsigned int virq, /* Caller has already checked that the IRQ is an SPI */ ASSERT(virq >= 32); ASSERT(virq < vgic_num_irqs(d)); + ASSERT(!is_lpi(virq)); vgic_lock_rank(v_target, rank, flags); @@ -184,6 +185,7 @@ int gic_remove_irq_from_guest(struct domain *d, unsigned int virq, ASSERT(spin_is_locked(&desc->lock)); ASSERT(test_bit(_IRQ_GUEST, &desc->status)); ASSERT(p->desc == desc); + ASSERT(!is_lpi(virq)); vgic_lock_rank(v_target, rank, flags); @@ -408,9 +410,13 @@ void gic_remove_from_queues(struct vcpu *v, unsigned int virtual_irq) spin_lock_irqsave(&v->arch.vgic.lock, flags); p = irq_to_pending(v, virtual_irq); - - if ( !list_empty(&p->lr_queue) ) + /* + * If an LPIs has been removed meanwhile, it has been cleaned up + * already, so nothing to remove here. + */ + if ( likely(p) && !list_empty(&p->lr_queue) ) list_del_init(&p->lr_queue); + spin_unlock_irqrestore(&v->arch.vgic.lock, flags); } @@ -418,6 +424,10 @@ void gic_raise_inflight_irq(struct vcpu *v, unsigned int virtual_irq) { struct pending_irq *n = irq_to_pending(v, virtual_irq); + /* If an LPI has been removed meanwhile, there is nothing left to raise. */ + if ( unlikely(!n) ) + return; + ASSERT(spin_is_locked(&v->arch.vgic.lock)); if ( list_empty(&n->lr_queue) ) @@ -437,20 +447,25 @@ void gic_raise_guest_irq(struct vcpu *v, unsigned int virtual_irq, { int i; unsigned int nr_lrs = gic_hw_ops->info->nr_lrs; + struct pending_irq *p = irq_to_pending(v, virtual_irq); ASSERT(spin_is_locked(&v->arch.vgic.lock)); + if ( unlikely(!p) ) + /* An unmapped LPI does not need to be raised. */ + return; + if ( v == current && list_empty(&v->arch.vgic.lr_pending) ) { i = find_first_zero_bit(&this_cpu(lr_mask), nr_lrs); if (i < nr_lrs) { set_bit(i, &this_cpu(lr_mask)); - gic_set_lr(i, irq_to_pending(v, virtual_irq), GICH_LR_PENDING); + gic_set_lr(i, p, GICH_LR_PENDING); return; } } - gic_add_to_lr_pending(v, irq_to_pending(v, virtual_irq)); + gic_add_to_lr_pending(v, p); } static void gic_update_one_lr(struct vcpu *v, int i) @@ -465,6 +480,17 @@ static void gic_update_one_lr(struct vcpu *v, int i) gic_hw_ops->read_lr(i, &lr_val); irq = lr_val.virq; p = irq_to_pending(v, irq); + /* An LPI might have been unmapped, in which case we just clean up here. */ + if ( unlikely(!p) ) + { + ASSERT(is_lpi(irq)); + + gic_hw_ops->clear_lr(i); + clear_bit(i, &this_cpu(lr_mask)); + + return; + } + if ( lr_val.state & GICH_LR_ACTIVE ) { set_bit(GIC_IRQ_GUEST_ACTIVE, &p->status); diff --git a/xen/arch/arm/vgic.c b/xen/arch/arm/vgic.c index d30f324..8a5d93b 100644 --- a/xen/arch/arm/vgic.c +++ b/xen/arch/arm/vgic.c @@ -242,6 +242,9 @@ bool vgic_migrate_irq(struct vcpu *old, struct vcpu *new, unsigned int irq) unsigned long flags; struct pending_irq *p = irq_to_pending(old, irq); + /* This will never be called for an LPI, as we don't migrate them. */ + ASSERT(!is_lpi(irq)); + /* nothing to do for virtual interrupts */ if ( p->desc == NULL ) return true; @@ -291,6 +294,9 @@ void arch_move_irqs(struct vcpu *v) struct vcpu *v_target; int i; + /* We don't migrate LPIs at the moment. */ + ASSERT(!is_lpi(vgic_num_irqs(d) - 1)); + for ( i = 32; i < vgic_num_irqs(d); i++ ) { v_target = vgic_get_target_vcpu(v, i); @@ -310,6 +316,9 @@ void vgic_disable_irqs(struct vcpu *v, uint32_t r, int n) int i = 0; struct vcpu *v_target; + /* LPIs will never be disabled via this function. */ + ASSERT(!is_lpi(32 * n + 31)); + while ( (i = find_next_bit(&mask, 32, i)) < 32 ) { irq = i + (32 * n); v_target = vgic_get_target_vcpu(v, irq); @@ -352,6 +361,9 @@ void vgic_enable_irqs(struct vcpu *v, uint32_t r, int n) struct vcpu *v_target; struct domain *d = v->domain; + /* LPIs will never be enabled via this function. */ + ASSERT(!is_lpi(32 * n + 31)); + while ( (i = find_next_bit(&mask, 32, i)) < 32 ) { irq = i + (32 * n); v_target = vgic_get_target_vcpu(v, irq); @@ -432,6 +444,12 @@ bool vgic_to_sgi(struct vcpu *v, register_t sgir, enum gic_sgi_mode irqmode, return true; } +/* + * Returns the pointer to the struct pending_irq belonging to the given + * interrupt. + * This can return NULL if called for an LPI which has been unmapped + * meanwhile. + */ struct pending_irq *irq_to_pending(struct vcpu *v, unsigned int irq) { struct pending_irq *n; @@ -475,6 +493,12 @@ void vgic_vcpu_inject_irq(struct vcpu *v, unsigned int virq) spin_lock_irqsave(&v->arch.vgic.lock, flags); n = irq_to_pending(v, virq); + /* If an LPI has been removed, there is nothing to inject here. */ + if ( unlikely(!n) ) + { + spin_unlock_irqrestore(&v->arch.vgic.lock, flags); + return; + } /* vcpu offline */ if ( test_bit(_VPF_down, &v->pause_flags) ) diff --git a/xen/include/asm-arm/event.h b/xen/include/asm-arm/event.h index 5330dfe..caefa50 100644 --- a/xen/include/asm-arm/event.h +++ b/xen/include/asm-arm/event.h @@ -19,6 +19,9 @@ static inline int local_events_need_delivery_nomask(void) struct pending_irq *p = irq_to_pending(current, current->domain->arch.evtchn_irq); + /* Does not work for LPIs. */ + ASSERT(!is_lpi(current->domain->arch.evtchn_irq)); + /* XXX: if the first interrupt has already been delivered, we should * check whether any other interrupts with priority higher than the * one in GICV_IAR are in the lr_pending queue or in the LR