From: Keith Busch Date: Wed, 27 Apr 2016 20:22:32 +0000 (-0600) Subject: x86/apic: Handle zero vector gracefully in clear_vector_irq() X-Git-Tag: firefly_0821_release~176^2~4^2~48^2~64 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=01d5ccd341290e771ac6b94b08c220df6f81a630;p=firefly-linux-kernel-4.4.55.git x86/apic: Handle zero vector gracefully in clear_vector_irq() commit 1bdb8970392a68489b469c3a330a1adb5ef61beb upstream. If x86_vector_alloc_irq() fails x86_vector_free_irqs() is invoked to cleanup the already allocated vectors. This subsequently calls clear_vector_irq(). The failed irq has no vector assigned, which triggers the BUG_ON(!vector) in clear_vector_irq(). We cannot suppress the call to x86_vector_free_irqs() for the failed interrupt, because the other data related to this irq must be cleaned up as well. So calling clear_vector_irq() with vector == 0 is legitimate. Remove the BUG_ON and return if vector is zero, [ tglx: Massaged changelog ] Fixes: b5dc8e6c21e7 "x86/irq: Use hierarchical irqdomain to manage CPU interrupt vectors" Signed-off-by: Keith Busch Signed-off-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman --- diff --git a/arch/x86/kernel/apic/vector.c b/arch/x86/kernel/apic/vector.c index 7af2505f20c2..df6b4eeac0bd 100644 --- a/arch/x86/kernel/apic/vector.c +++ b/arch/x86/kernel/apic/vector.c @@ -254,7 +254,8 @@ static void clear_irq_vector(int irq, struct apic_chip_data *data) struct irq_desc *desc; int cpu, vector; - BUG_ON(!data->cfg.vector); + if (!data->cfg.vector) + return; vector = data->cfg.vector; for_each_cpu_and(cpu, data->domain, cpu_online_mask)