linux-kernel - [PATCH 4.4 325/342] x86/irq: Do not use apic_chip_data.old

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Date:	Tue, 01 Mar 2016 23:55:40 +0000
From:	Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:	<linux-kernel@...r.kernel.org>
Cc:	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	<stable@...r.kernel.org>, Jiang Liu <jiang.liu@...ux.intel.com>,
	Borislav Petkov <bp@...en8.de>,
	Joe Lawrence <joe.lawrence@...atus.com>,
	Jeremiah Mahler <jmmahler@...il.com>,
	<andy.shevchenko@...il.com>, Guenter Roeck <linux@...ck-us.net>,
	Thomas Gleixner <tglx@...utronix.de>
Subject: [PATCH 4.4 325/342] x86/irq: Do not use apic_chip_data.old_domain as temporary buffer

4.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Jiang Liu <jiang.liu@...ux.intel.com>

commit 8a580f70f6936ec095da217018cdeeb5835c0207 upstream.

Function __assign_irq_vector() makes use of apic_chip_data.old_domain as a
temporary buffer, which is in the way of using apic_chip_data.old_domain for
synchronizing the vector cleanup with the vector assignement code.

Use a proper temporary cpumask for this.

[ tglx: Renamed the mask to searched_cpumask for clarity ]

Signed-off-by: Jiang Liu <jiang.liu@...ux.intel.com>
Tested-by: Borislav Petkov <bp@...en8.de>
Tested-by: Joe Lawrence <joe.lawrence@...atus.com>
Cc: Jeremiah Mahler <jmmahler@...il.com>
Cc: andy.shevchenko@...il.com
Cc: Guenter Roeck <linux@...ck-us.net>
Link: http://lkml.kernel.org/r/1450880014-11741-1-git-send-email-jiang.liu@linux.intel.com
Signed-off-by: Thomas Gleixner <tglx@...utronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>

---
 arch/x86/kernel/apic/vector.c |    8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

--- a/arch/x86/kernel/apic/vector.c
+++ b/arch/x86/kernel/apic/vector.c
@@ -30,7 +30,7 @@ struct apic_chip_data {
 
 struct irq_domain *x86_vector_domain;
 static DEFINE_RAW_SPINLOCK(vector_lock);
-static cpumask_var_t vector_cpumask;
+static cpumask_var_t vector_cpumask, searched_cpumask;
 static struct irq_chip lapic_controller;
 #ifdef	CONFIG_X86_IO_APIC
 static struct apic_chip_data *legacy_irq_data[NR_IRQS_LEGACY];
@@ -124,6 +124,7 @@ static int __assign_irq_vector(int irq,
 	/* Only try and allocate irqs on cpus that are present */
 	err = -ENOSPC;
 	cpumask_clear(d->old_domain);
+	cpumask_clear(searched_cpumask);
 	cpu = cpumask_first_and(mask, cpu_online_mask);
 	while (cpu < nr_cpu_ids) {
 		int new_cpu, vector, offset;
@@ -157,9 +158,9 @@ next:
 		}
 
 		if (unlikely(current_vector == vector)) {
-			cpumask_or(d->old_domain, d->old_domain,
+			cpumask_or(searched_cpumask, searched_cpumask,
 				   vector_cpumask);
-			cpumask_andnot(vector_cpumask, mask, d->old_domain);
+			cpumask_andnot(vector_cpumask, mask, searched_cpumask);
 			cpu = cpumask_first_and(vector_cpumask,
 						cpu_online_mask);
 			continue;
@@ -404,6 +405,7 @@ int __init arch_early_irq_init(void)
 	arch_init_htirq_domain(x86_vector_domain);
 
 	BUG_ON(!alloc_cpumask_var(&vector_cpumask, GFP_KERNEL));
+	BUG_ON(!alloc_cpumask_var(&searched_cpumask, GFP_KERNEL));
 
 	return arch_early_ioapic_init();
 }