lkml.org 
[lkml]   [2010]   [Jan]   [26]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[93/98] KVM: fix lock imbalance in kvm_*_irq_source_id()
2.6.32-stable review patch.  If anyone has any objections, please let us know.

------------------

From: Jiri Slaby <jirislaby@gmail.com>

commit 0c6ddcebd8303ada6faefa6f72ac18b6230320c4 upstream.

Stanse found 2 lock imbalances in kvm_request_irq_source_id and
kvm_free_irq_source_id. They omit to unlock kvm->irq_lock on fail paths.

Fix that by adding unlock labels at the end of the functions and jump
there from the fail paths.

Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
virt/kvm/irq_comm.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)

--- a/virt/kvm/irq_comm.c
+++ b/virt/kvm/irq_comm.c
@@ -209,11 +209,13 @@ int kvm_request_irq_source_id(struct kvm

if (irq_source_id >= BITS_PER_LONG) {
printk(KERN_WARNING "kvm: exhaust allocatable IRQ sources!\n");
- return -EFAULT;
+ irq_source_id = -EFAULT;
+ goto unlock;
}

ASSERT(irq_source_id != KVM_USERSPACE_IRQ_SOURCE_ID);
set_bit(irq_source_id, bitmap);
+unlock:
mutex_unlock(&kvm->irq_lock);

return irq_source_id;
@@ -229,11 +231,12 @@ void kvm_free_irq_source_id(struct kvm *
if (irq_source_id < 0 ||
irq_source_id >= BITS_PER_LONG) {
printk(KERN_ERR "kvm: IRQ source ID out of range!\n");
- return;
+ goto unlock;
}
for (i = 0; i < KVM_IOAPIC_NUM_PINS; i++)
clear_bit(irq_source_id, &kvm->arch.irq_states[i]);
clear_bit(irq_source_id, &kvm->arch.irq_sources_bitmap);
+unlock:
mutex_unlock(&kvm->irq_lock);
}




\
 
 \ /
  Last update: 2010-01-27 00:49    [W:0.182 / U:2.984 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site