From: Paul E. McKenney Date: Wed, 3 Sep 2008 09:15:30 +0000 (-0700) Subject: sparc64: Prevent sparc64 from invoking irq handlers on offline CPUs X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=4d084617fb0d025c42c242362d1f27d337e2d407;p=GitHub%2FLineageOS%2FG12%2Fandroid_kernel_amlogic_linux-4.9.git sparc64: Prevent sparc64 from invoking irq handlers on offline CPUs Make sparc64 refrain from clearing a given to-be-offlined CPU's bit in the cpu_online_mask until it has processed pending irqs. This change prevents other CPUs from being blindsided by an apparently offline CPU nevertheless changing globally visible state. Signed-off-by: Paul E. McKenney Signed-off-by: David S. Miller --- diff --git a/arch/sparc64/kernel/smp.c b/arch/sparc64/kernel/smp.c index 0712a445f98e..2be166c544ca 100644 --- a/arch/sparc64/kernel/smp.c +++ b/arch/sparc64/kernel/smp.c @@ -1303,10 +1303,6 @@ int __cpu_disable(void) c->core_id = 0; c->proc_id = -1; - ipi_call_lock(); - cpu_clear(cpu, cpu_online_map); - ipi_call_unlock(); - smp_wmb(); /* Make sure no interrupts point to this cpu. */ @@ -1316,6 +1312,10 @@ int __cpu_disable(void) mdelay(1); local_irq_disable(); + ipi_call_lock(); + cpu_clear(cpu, cpu_online_map); + ipi_call_unlock(); + return 0; }