Commit 7df19ad4 authored by Thomas Gleixner's avatar Thomas Gleixner Committed by Greg Kroah-Hartman

x86/irq: Call chip->irq_set_affinity in proper context

commit e23b257c upstream.

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: default avatarBorislav Petkov <bp@alien8.de>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Jeremiah Mahler <jmmahler@gmail.com>
Cc: andy.shevchenko@gmail.com
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Joe Lawrence <joe.lawrence@stratus.com>
Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1601140919420.3575@nanosSigned-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent eeb241d4
...@@ -2521,6 +2521,7 @@ void __init setup_ioapic_dest(void) ...@@ -2521,6 +2521,7 @@ void __init setup_ioapic_dest(void)
{ {
int pin, ioapic, irq, irq_entry; int pin, ioapic, irq, irq_entry;
const struct cpumask *mask; const struct cpumask *mask;
struct irq_desc *desc;
struct irq_data *idata; struct irq_data *idata;
struct irq_chip *chip; struct irq_chip *chip;
...@@ -2536,7 +2537,9 @@ void __init setup_ioapic_dest(void) ...@@ -2536,7 +2537,9 @@ void __init setup_ioapic_dest(void)
if (irq < 0 || !mp_init_irq_at_boot(ioapic, irq)) if (irq < 0 || !mp_init_irq_at_boot(ioapic, irq))
continue; 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 * Honour affinities which have been set in early boot
...@@ -2550,6 +2553,7 @@ void __init setup_ioapic_dest(void) ...@@ -2550,6 +2553,7 @@ void __init setup_ioapic_dest(void)
/* Might be lapic_chip for irq 0 */ /* Might be lapic_chip for irq 0 */
if (chip->irq_set_affinity) if (chip->irq_set_affinity)
chip->irq_set_affinity(idata, mask, false); chip->irq_set_affinity(idata, mask, false);
raw_spin_unlock_irq(&desc->lock);
} }
} }
#endif #endif
......
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