diff options
| author | Thomas Gleixner <[email protected]> | 2016-01-14 08:43:38 +0100 |
|---|---|---|
| committer | Thomas Gleixner <[email protected]> | 2016-01-15 13:43:58 +0100 |
| commit | e23b257c293ce4bcc8cabb2aa3097b6ed8a8261a (patch) | |
| tree | e05376f96aaa28babe15029771536483dbf3c108 | |
| parent | 7030a7e9321166eef44c811fe4af4d460360d424 (diff) | |
x86/irq: Call chip->irq_set_affinity in proper context
setup_ioapic_dest() calls irqchip->irq_set_affinity() completely
unprotected. That's wrong in several aspects:
- it opens a race window where irq_set_affinity() can be interrupted and the
irq chip left in unconsistent state.
- it triggers a lockdep splat when we fix the vector race for 4.3+ because
vector lock is taken with interrupts enabled.
The proper calling convention is irq descriptor lock held and interrupts
disabled.
Reported-and-tested-by: Borislav Petkov <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Cc: Jiang Liu <[email protected]>
Cc: Jeremiah Mahler <[email protected]>
Cc: [email protected]
Cc: Guenter Roeck <[email protected]>
Cc: Joe Lawrence <[email protected]>
Cc: [email protected]
Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1601140919420.3575@nanos
Signed-off-by: Thomas Gleixner <[email protected]>
| -rw-r--r-- | arch/x86/kernel/apic/io_apic.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c index f25321894ad2..fdb0fbfb1197 100644 --- a/arch/x86/kernel/apic/io_apic.c +++ b/arch/x86/kernel/apic/io_apic.c @@ -2521,6 +2521,7 @@ void __init setup_ioapic_dest(void) { int pin, ioapic, irq, irq_entry; const struct cpumask *mask; + struct irq_desc *desc; struct irq_data *idata; struct irq_chip *chip; @@ -2536,7 +2537,9 @@ void __init setup_ioapic_dest(void) if (irq < 0 || !mp_init_irq_at_boot(ioapic, irq)) continue; - idata = irq_get_irq_data(irq); + desc = irq_to_desc(irq); + raw_spin_lock_irq(&desc->lock); + idata = irq_desc_get_irq_data(desc); /* * Honour affinities which have been set in early boot @@ -2550,6 +2553,7 @@ void __init setup_ioapic_dest(void) /* Might be lapic_chip for irq 0 */ if (chip->irq_set_affinity) chip->irq_set_affinity(idata, mask, false); + raw_spin_unlock_irq(&desc->lock); } } #endif |