diff options
author | Thomas Gleixner <tglx@linutronix.de> | 2015-07-05 17:12:35 (GMT) |
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committer | Thomas Gleixner <tglx@linutronix.de> | 2015-07-07 09:54:04 (GMT) |
commit | 09cf92b784fae6109450c5d64f9908066d605249 (patch) | |
tree | 5c4dcac5d736a39342f24a4d7d627a2290f54fb1 /arch | |
parent | cbb24dc761d95fe39a7a122bb1b298e9604cae15 (diff) | |
download | linux-09cf92b784fae6109450c5d64f9908066d605249.tar.xz |
x86/irq: Retrieve irq data after locking irq_desc
irq_data is protected by irq_desc->lock, so retrieving the irq chip
from irq_data outside the lock is racy vs. an concurrent update. Move
it into the lock held region.
While at it add a comment why the vector walk does not require
vector_lock.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: xiao jin <jin.xiao@intel.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Borislav Petkov <bp@suse.de>
Cc: Yanmin Zhang <yanmin_zhang@linux.intel.com>
Link: http://lkml.kernel.org/r/20150705171102.331320612@linutronix.de
Diffstat (limited to 'arch')
-rw-r--r-- | arch/x86/kernel/irq.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/arch/x86/kernel/irq.c b/arch/x86/kernel/irq.c index 85ca76e..c7dfe1b 100644 --- a/arch/x86/kernel/irq.c +++ b/arch/x86/kernel/irq.c @@ -497,6 +497,11 @@ void fixup_irqs(void) */ mdelay(1); + /* + * We can walk the vector array of this cpu without holding + * vector_lock because the cpu is already marked !online, so + * nothing else will touch it. + */ for (vector = FIRST_EXTERNAL_VECTOR; vector < NR_VECTORS; vector++) { unsigned int irr; @@ -508,9 +513,9 @@ void fixup_irqs(void) irq = __this_cpu_read(vector_irq[vector]); desc = irq_to_desc(irq); + raw_spin_lock(&desc->lock); data = irq_desc_get_irq_data(desc); chip = irq_data_get_irq_chip(data); - raw_spin_lock(&desc->lock); if (chip->irq_retrigger) { chip->irq_retrigger(data); __this_cpu_write(vector_irq[vector], VECTOR_RETRIGGERED); |