[tip:x86/urgent] x86/irq: Do not reuse struct apic_chip_data.old_domain as temporary buffer

[tip-bot for Jiang Liu <tipbot@zytor.com>]

Commit-ID:  6dd7cb991fcbfef55d8bf3d22b8a87f9d5007e20
Gitweb:     http://git.kernel.org/tip/6dd7cb991fcbfef55d8bf3d22b8a87f9d5007e20
Author:     Jiang Liu <jiang.liu@linux.intel.com>
AuthorDate: Mon, 30 Nov 2015 16:09:26 +0800
Committer:  Thomas Gleixner <tglx@linutronix.de>
CommitDate: Thu, 10 Dec 2015 19:32:07 +0100

x86/irq: Do not reuse struct apic_chip_data.old_domain as temporary buffer

Function __assign_irq_vector() makes use of apic_chip_data.old_domain
as a temporary buffer, which causes trouble to rollback logic in case of
failure. So use a dedicated temporary buffer for __assign_irq_vector().

Fixes: a782a7e46bb5 "x86/irq: Store irq descriptor in vector array"
Reported-and-tested-by: Joe Lawrence <joe.lawrence@stratus.com>
Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Link: http://lkml.kernel.org/r/1448870970-1461-1-git-send-email-jiang.liu@linux.intel.com
Cc: stable@vger.kernel.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
 arch/x86/kernel/apic/vector.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kernel/apic/vector.c b/arch/x86/kernel/apic/vector.c
index 861bc59..d6ec36b 100644
--- 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, used_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, struct apic_chip_data *d,
 	/* Only try and allocate irqs on cpus that are present */
 	err = -ENOSPC;
 	cpumask_clear(d->old_domain);
+	cpumask_clear(used_cpumask);
 	cpu = cpumask_first_and(mask, cpu_online_mask);
 	while (cpu < nr_cpu_ids) {
 		int new_cpu, vector, offset;
@@ -157,9 +158,8 @@ next:
 		}
 
 		if (unlikely(current_vector == vector)) {
-			cpumask_or(d->old_domain, d->old_domain,
-				   vector_cpumask);
-			cpumask_andnot(vector_cpumask, mask, d->old_domain);
+			cpumask_or(used_cpumask, used_cpumask, vector_cpumask);
+			cpumask_andnot(vector_cpumask, mask, used_cpumask);
 			cpu = cpumask_first_and(vector_cpumask,
 						cpu_online_mask);
 			continue;
@@ -404,6 +404,7 @@ 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(&used_cpumask, GFP_KERNEL));
 
 	return arch_early_ioapic_init();
 }