diff options
| author | Joerg Roedel | 2015-02-04 13:33:33 +0100 |
|---|---|---|
| committer | Ingo Molnar | 2015-02-18 15:01:42 +0100 |
| commit | d97eb8966c91f2c9d05f0a22eb89ed5b76d966d1 (patch) | |
| tree | 57d7dbcfd946a53ed327066dfffebdc7bb5f8349 | |
| parent | 1ea76fbadd667b19c4fa4466f3a3b55a505e83d9 (diff) | |
x86/irq: Check for valid irq descriptor in check_irq_vectors_for_cpu_disable()
When an interrupt is migrated away from a cpu it will stay
in its vector_irq array until smp_irq_move_cleanup_interrupt
succeeded. The cfg->move_in_progress flag is cleared already
when the IPI was sent.
When the interrupt is destroyed after migration its 'struct
irq_desc' is freed and the vector_irq arrays are cleaned up.
But since cfg->move_in_progress is already 0 the references
at cpus before the last migration will not be cleared. So
this would leave a reference to an already destroyed irq
alive.
When the cpu is taken down at this point, the
check_irq_vectors_for_cpu_disable() function finds a valid irq
number in the vector_irq array, but gets NULL for its
descriptor and dereferences it, causing a kernel panic.
This has been observed on real systems at shutdown. Add a
check to check_irq_vectors_for_cpu_disable() for a valid
'struct irq_desc' to prevent this issue.
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Jiang Liu <jiang.liu@linux.intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jan Beulich <JBeulich@suse.com>
Cc: K. Y. Srinivasan <kys@microsoft.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: alnovak@suse.com
Cc: joro@8bytes.org
Link: http://lkml.kernel.org/r/20150204132754.GA10078@suse.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
| -rw-r--r-- | arch/x86/kernel/irq.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/x86/kernel/irq.c b/arch/x86/kernel/irq.c index 705ef8d48e2d..67b1cbe0093a 100644 --- a/arch/x86/kernel/irq.c +++ b/arch/x86/kernel/irq.c @@ -302,6 +302,9 @@ int check_irq_vectors_for_cpu_disable(void) irq = __this_cpu_read(vector_irq[vector]); if (irq >= 0) { desc = irq_to_desc(irq); + if (!desc) + continue; + data = irq_desc_get_irq_data(desc); cpumask_copy(&affinity_new, data->affinity); cpu_clear(this_cpu, affinity_new); |