From 0a1ad60d7a7eb433095bc1b2c8b475f3f278f61d Mon Sep 17 00:00:00 2001 From: Jan Beulich Date: Mon, 26 Jun 2006 13:56:43 +0200 Subject: [PATCH] x86_64: serialize assign_irq_vector() use of static variables Since assign_irq_vector() can be called at runtime, its access of static variables should be protected by a lock. Signed-off-by: Jan Beulich Signed-off-by: Andi Kleen Signed-off-by: Linus Torvalds --- arch/x86_64/kernel/io_apic.c | 18 ++++++++++++++---- 1 file changed, 14 insertions(+), 4 deletions(-) (limited to 'arch/x86_64/kernel/io_apic.c') diff --git a/arch/x86_64/kernel/io_apic.c b/arch/x86_64/kernel/io_apic.c index 9cc7031b715..062b10daeba 100644 --- a/arch/x86_64/kernel/io_apic.c +++ b/arch/x86_64/kernel/io_apic.c @@ -56,6 +56,7 @@ int timer_over_8254 __initdata = 0; static struct { int pin, apic; } ioapic_i8259 = { -1, -1 }; static DEFINE_SPINLOCK(ioapic_lock); +static DEFINE_SPINLOCK(vector_lock); /* * # of IRQ routing registers @@ -834,10 +835,16 @@ u8 irq_vector[NR_IRQ_VECTORS] __read_mostly = { FIRST_DEVICE_VECTOR , 0 }; int assign_irq_vector(int irq) { static int current_vector = FIRST_DEVICE_VECTOR, offset = 0; + int vector; BUG_ON(irq != AUTO_ASSIGN && (unsigned)irq >= NR_IRQ_VECTORS); - if (irq != AUTO_ASSIGN && IO_APIC_VECTOR(irq) > 0) + + spin_lock(&vector_lock); + + if (irq != AUTO_ASSIGN && IO_APIC_VECTOR(irq) > 0) { + spin_unlock(&vector_lock); return IO_APIC_VECTOR(irq); + } next: current_vector += 8; if (current_vector == IA32_SYSCALL_VECTOR) @@ -849,11 +856,14 @@ next: current_vector = FIRST_DEVICE_VECTOR + offset; } - vector_irq[current_vector] = irq; + vector = current_vector; + vector_irq[vector] = irq; if (irq != AUTO_ASSIGN) - IO_APIC_VECTOR(irq) = current_vector; + IO_APIC_VECTOR(irq) = vector; + + spin_unlock(&vector_lock); - return current_vector; + return vector; } extern void (*interrupt[NR_IRQS])(void); -- cgit v1.2.3