From patchwork Mon Apr 29 11:25:03 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Jan Beulich X-Patchwork-Id: 10921689 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id C0D2D1515 for ; Mon, 29 Apr 2019 11:26:55 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id AE1972871E for ; Mon, 29 Apr 2019 11:26:55 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id A272F287E7; Mon, 29 Apr 2019 11:26:55 +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=-5.2 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, 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 AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 238CC2871E for ; Mon, 29 Apr 2019 11:26:55 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1hL4PI-00084Q-Hx; Mon, 29 Apr 2019 11:25:12 +0000 Received: from all-amaz-eas1.inumbo.com ([34.197.232.57] helo=us1-amaz-eas2.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1hL4PG-000845-Sn for xen-devel@lists.xenproject.org; Mon, 29 Apr 2019 11:25:10 +0000 X-Inumbo-ID: 71bb1362-6a71-11e9-8ca8-4f52f2f08acb Received: from prv1-mh.provo.novell.com (unknown [137.65.248.33]) by us1-amaz-eas2.inumbo.com (Halon) with ESMTPS id 71bb1362-6a71-11e9-8ca8-4f52f2f08acb; Mon, 29 Apr 2019 11:25:09 +0000 (UTC) Received: from INET-PRV1-MTA by prv1-mh.provo.novell.com with Novell_GroupWise; Mon, 29 Apr 2019 05:25:08 -0600 Message-Id: <5CC6DF0F0200007800229EBC@prv1-mh.provo.novell.com> X-Mailer: Novell GroupWise Internet Agent 18.1.0 Date: Mon, 29 Apr 2019 05:25:03 -0600 From: "Jan Beulich" To: "xen-devel" References: <5CC6DD090200007800229E80@prv1-mh.provo.novell.com> In-Reply-To: <5CC6DD090200007800229E80@prv1-mh.provo.novell.com> Mime-Version: 1.0 Content-Disposition: inline Subject: [Xen-devel] [PATCH 5/9] x86/IRQ: fix locking around vector management X-BeenThere: xen-devel@lists.xenproject.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Cc: Andrew Cooper , Wei Liu , Roger Pau Monne Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" X-Virus-Scanned: ClamAV using ClamSMTP All of __{assign,bind,clear}_irq_vector() manipulate struct irq_desc fields, and hence ought to be called with the descriptor lock held in addition to vector_lock. This is currently the case for only set_desc_affinity() and destroy_irq(), which also clarifies what the nesting behavior between the locks has to be. Reflect the new expectation by having these functions all take a descriptor as parameter instead of an interrupt number. Drop one of the two leading underscores from all three functions at the same time. There's one case left where descriptors get manipulated with just vector_lock held: setup_vector_irq() assumes its caller to acquire vector_lock, and hence can't itself acquire the descriptor locks (wrong lock order). I don't currently see how to address this. Signed-off-by: Jan Beulich Reviewed-by: Roger Pau Monné --- a/xen/arch/x86/irq.c +++ b/xen/arch/x86/irq.c @@ -27,6 +27,7 @@ #include static int parse_irq_vector_map_param(const char *s); +static void _clear_irq_vector(struct irq_desc *desc); /* opt_noirqbalance: If true, software IRQ balancing/affinity is disabled. */ bool __read_mostly opt_noirqbalance; @@ -112,13 +113,12 @@ static void trace_irq_mask(u32 event, in trace_var(event, 1, sizeof(d), &d); } -static int __init __bind_irq_vector(int irq, int vector, const cpumask_t *cpu_mask) +static int __init _bind_irq_vector(struct irq_desc *desc, int vector, + const cpumask_t *cpu_mask) { cpumask_t online_mask; int cpu; - struct irq_desc *desc = irq_to_desc(irq); - BUG_ON((unsigned)irq >= nr_irqs); BUG_ON((unsigned)vector >= NR_VECTORS); cpumask_and(&online_mask, cpu_mask, &cpu_online_map); @@ -129,9 +129,9 @@ static int __init __bind_irq_vector(int return 0; if ( desc->arch.vector != IRQ_VECTOR_UNASSIGNED ) return -EBUSY; - trace_irq_mask(TRC_HW_IRQ_BIND_VECTOR, irq, vector, &online_mask); + trace_irq_mask(TRC_HW_IRQ_BIND_VECTOR, desc->irq, vector, &online_mask); for_each_cpu(cpu, &online_mask) - per_cpu(vector_irq, cpu)[vector] = irq; + per_cpu(vector_irq, cpu)[vector] = desc->irq; desc->arch.vector = vector; cpumask_copy(desc->arch.cpu_mask, &online_mask); if ( desc->arch.used_vectors ) @@ -145,12 +145,18 @@ static int __init __bind_irq_vector(int int __init bind_irq_vector(int irq, int vector, const cpumask_t *cpu_mask) { + struct irq_desc *desc = irq_to_desc(irq); unsigned long flags; int ret; - spin_lock_irqsave(&vector_lock, flags); - ret = __bind_irq_vector(irq, vector, cpu_mask); - spin_unlock_irqrestore(&vector_lock, flags); + BUG_ON((unsigned)irq >= nr_irqs); + + spin_lock_irqsave(&desc->lock, flags); + spin_lock(&vector_lock); + ret = _bind_irq_vector(desc, vector, cpu_mask); + spin_unlock(&vector_lock); + spin_unlock_irqrestore(&desc->lock, flags); + return ret; } @@ -235,7 +241,9 @@ void destroy_irq(unsigned int irq) spin_lock_irqsave(&desc->lock, flags); desc->handler = &no_irq_type; - clear_irq_vector(irq); + spin_lock(&vector_lock); + _clear_irq_vector(desc); + spin_unlock(&vector_lock); desc->arch.used_vectors = NULL; spin_unlock_irqrestore(&desc->lock, flags); @@ -256,11 +264,11 @@ static void release_old_vec(struct irq_d } } -static void __clear_irq_vector(int irq) +static void _clear_irq_vector(struct irq_desc *desc) { - int cpu, vector, old_vector; + unsigned int cpu; + int vector, old_vector, irq = desc->irq; cpumask_t tmp_mask; - struct irq_desc *desc = irq_to_desc(irq); BUG_ON(!desc->arch.vector); @@ -306,11 +314,14 @@ static void __clear_irq_vector(int irq) void clear_irq_vector(int irq) { + struct irq_desc *desc = irq_to_desc(irq); unsigned long flags; - spin_lock_irqsave(&vector_lock, flags); - __clear_irq_vector(irq); - spin_unlock_irqrestore(&vector_lock, flags); + spin_lock_irqsave(&desc->lock, flags); + spin_lock(&vector_lock); + _clear_irq_vector(desc); + spin_unlock(&vector_lock); + spin_unlock_irqrestore(&desc->lock, flags); } int irq_to_vector(int irq) @@ -445,8 +456,7 @@ static vmask_t *irq_get_used_vector_mask return ret; } -static int __assign_irq_vector( - int irq, struct irq_desc *desc, const cpumask_t *mask) +static int _assign_irq_vector(struct irq_desc *desc, const cpumask_t *mask) { /* * NOTE! The local APIC isn't very good at handling @@ -460,7 +470,8 @@ static int __assign_irq_vector( * 0x80, because int 0x80 is hm, kind of importantish. ;) */ static int current_vector = FIRST_DYNAMIC_VECTOR, current_offset = 0; - int cpu, err, old_vector; + unsigned int cpu; + int err, old_vector, irq = desc->irq; cpumask_t tmp_mask; vmask_t *irq_used_vectors = NULL; @@ -570,8 +581,12 @@ int assign_irq_vector(int irq, const cpu BUG_ON(irq >= nr_irqs || irq <0); - spin_lock_irqsave(&vector_lock, flags); - ret = __assign_irq_vector(irq, desc, mask ?: TARGET_CPUS); + spin_lock_irqsave(&desc->lock, flags); + + spin_lock(&vector_lock); + ret = _assign_irq_vector(desc, mask ?: TARGET_CPUS); + spin_unlock(&vector_lock); + if ( !ret ) { ret = desc->arch.vector; @@ -580,7 +595,8 @@ int assign_irq_vector(int irq, const cpu else cpumask_setall(desc->affinity); } - spin_unlock_irqrestore(&vector_lock, flags); + + spin_unlock_irqrestore(&desc->lock, flags); return ret; } @@ -754,7 +770,6 @@ void irq_complete_move(struct irq_desc * unsigned int set_desc_affinity(struct irq_desc *desc, const cpumask_t *mask) { - unsigned int irq; int ret; unsigned long flags; cpumask_t dest_mask; @@ -762,10 +777,8 @@ unsigned int set_desc_affinity(struct ir if (!cpumask_intersects(mask, &cpu_online_map)) return BAD_APICID; - irq = desc->irq; - spin_lock_irqsave(&vector_lock, flags); - ret = __assign_irq_vector(irq, desc, mask); + ret = _assign_irq_vector(desc, mask); spin_unlock_irqrestore(&vector_lock, flags); if (ret < 0)