Commit 0ca4b6b0 authored by Matthew Wilcox's avatar Matthew Wilcox Committed by Linus Torvalds
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x86: Fix interrupt leak due to migration

When we migrate an interrupt from one CPU to another, we set the
move_in_progress flag and clean up the vectors later once they're not
being used.  If you're unlucky and call destroy_irq() before the vectors
become un-used, the move_in_progress flag is never cleared, which causes
the interrupt to become unusable.

This was discovered by Jesse Brandeburg for whom it manifested as an
MSI-X device refusing to use MSI-X mode when the driver was unloaded
and reloaded repeatedly.
Signed-off-by: default avatarMatthew Wilcox <>
Signed-off-by: default avatarLinus Torvalds <>
parent 23918b03
......@@ -1140,6 +1140,20 @@ static void __clear_irq_vector(int irq)
cfg->vector = 0;
if (likely(!cfg->move_in_progress))
cpus_and(mask, cfg->old_domain, cpu_online_map);
for_each_cpu_mask_nr(cpu, mask) {
for (vector = FIRST_EXTERNAL_VECTOR; vector < NR_VECTORS;
vector++) {
if (per_cpu(vector_irq, cpu)[vector] != irq)
per_cpu(vector_irq, cpu)[vector] = -1;
cfg->move_in_progress = 0;
void __setup_vector_irq(int cpu)
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