Re: [PATCH] arm, kvm: fix double lock on cpu_add_remove_lock

2014-04-08 Thread Rafael J. Wysocki 
On Monday, April 07, 2014 12:14:22 PM Srivatsa S. Bhat wrote:
 On 04/06/2014 11:06 PM, Ming Lei wrote:
  The patch of arm, kvm: Fix CPU hotplug callback registration
  in -next tree holds the lock before calling the two functions:
  
  kvm_vgic_hyp_init()
  kvm_timer_hyp_init()
  
  and both the two functions are calling register_cpu_notifier()
  to register cpu notifier, so cause double lock on cpu_add_remove_lock.
  
  Considered that both two functions are only called inside
  kvm_arch_init() with holding cpu_add_remove_lock, so simply use
  __register_cpu_notifier() to fix the problem.
  
  Cc: Paolo Bonzini pbonz...@redhat.com
  Cc: Christoffer Dall christoffer.d...@linaro.org
  Cc: Srivatsa S. Bhat srivatsa.b...@linux.vnet.ibm.com
  Cc: Rafael J. Wysocki rafael.j.wyso...@intel.com
  Signed-off-by: Ming Lei tom.leim...@gmail.com
 
 Sorry for missing that, and thank you for the fix!
 
 Reviewed-by: Srivatsa S. Bhat srivatsa.b...@linux.vnet.ibm.com

Applied, thanks!

I'm going to include this into my next pull request.

  ---
   virt/kvm/arm/arch_timer.c |2 +-
   virt/kvm/arm/vgic.c   |2 +-
   2 files changed, 2 insertions(+), 2 deletions(-)
  
  diff --git a/virt/kvm/arm/arch_timer.c b/virt/kvm/arm/arch_timer.c
  index 5081e80..22fa819 100644
  --- a/virt/kvm/arm/arch_timer.c
  +++ b/virt/kvm/arm/arch_timer.c
  @@ -277,7 +277,7 @@ int kvm_timer_hyp_init(void)
  
  host_vtimer_irq = ppi;
  
  -   err = register_cpu_notifier(kvm_timer_cpu_nb);
  +   err = __register_cpu_notifier(kvm_timer_cpu_nb);
  if (err) {
  kvm_err(Cannot register timer CPU notifier\n);
  goto out_free;
  diff --git a/virt/kvm/arm/vgic.c b/virt/kvm/arm/vgic.c
  index 8ca405c..47b2983 100644
  --- a/virt/kvm/arm/vgic.c
  +++ b/virt/kvm/arm/vgic.c
  @@ -1496,7 +1496,7 @@ int kvm_vgic_hyp_init(void)
  goto out;
  }
  
  -   ret = register_cpu_notifier(vgic_cpu_nb);
  +   ret = __register_cpu_notifier(vgic_cpu_nb);
  if (ret) {
  kvm_err(Cannot register vgic CPU notifier\n);
  goto out_free_irq;
  
 
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Re: [PATCH] arm, kvm: fix double lock on cpu_add_remove_lock

2014-04-07 Thread Srivatsa S. Bhat 
On 04/06/2014 11:06 PM, Ming Lei wrote:
 The patch of arm, kvm: Fix CPU hotplug callback registration
 in -next tree holds the lock before calling the two functions:
 
   kvm_vgic_hyp_init()
   kvm_timer_hyp_init()
 
 and both the two functions are calling register_cpu_notifier()
 to register cpu notifier, so cause double lock on cpu_add_remove_lock.
 
 Considered that both two functions are only called inside
 kvm_arch_init() with holding cpu_add_remove_lock, so simply use
 __register_cpu_notifier() to fix the problem.
 
 Cc: Paolo Bonzini pbonz...@redhat.com
 Cc: Christoffer Dall christoffer.d...@linaro.org
 Cc: Srivatsa S. Bhat srivatsa.b...@linux.vnet.ibm.com
 Cc: Rafael J. Wysocki rafael.j.wyso...@intel.com
 Signed-off-by: Ming Lei tom.leim...@gmail.com

Sorry for missing that, and thank you for the fix!

Reviewed-by: Srivatsa S. Bhat srivatsa.b...@linux.vnet.ibm.com

Regards,
Srivatsa S. Bhat

 ---
  virt/kvm/arm/arch_timer.c |2 +-
  virt/kvm/arm/vgic.c   |2 +-
  2 files changed, 2 insertions(+), 2 deletions(-)
 
 diff --git a/virt/kvm/arm/arch_timer.c b/virt/kvm/arm/arch_timer.c
 index 5081e80..22fa819 100644
 --- a/virt/kvm/arm/arch_timer.c
 +++ b/virt/kvm/arm/arch_timer.c
 @@ -277,7 +277,7 @@ int kvm_timer_hyp_init(void)
 
   host_vtimer_irq = ppi;
 
 - err = register_cpu_notifier(kvm_timer_cpu_nb);
 + err = __register_cpu_notifier(kvm_timer_cpu_nb);
   if (err) {
   kvm_err(Cannot register timer CPU notifier\n);
   goto out_free;
 diff --git a/virt/kvm/arm/vgic.c b/virt/kvm/arm/vgic.c
 index 8ca405c..47b2983 100644
 --- a/virt/kvm/arm/vgic.c
 +++ b/virt/kvm/arm/vgic.c
 @@ -1496,7 +1496,7 @@ int kvm_vgic_hyp_init(void)
   goto out;
   }
 
 - ret = register_cpu_notifier(vgic_cpu_nb);
 + ret = __register_cpu_notifier(vgic_cpu_nb);
   if (ret) {
   kvm_err(Cannot register vgic CPU notifier\n);
   goto out_free_irq;
 

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[PATCH] arm, kvm: fix double lock on cpu_add_remove_lock

2014-04-06 Thread Ming Lei 
The patch of arm, kvm: Fix CPU hotplug callback registration
in -next tree holds the lock before calling the two functions:

kvm_vgic_hyp_init()
kvm_timer_hyp_init()

and both the two functions are calling register_cpu_notifier()
to register cpu notifier, so cause double lock on cpu_add_remove_lock.

Considered that both two functions are only called inside
kvm_arch_init() with holding cpu_add_remove_lock, so simply use
__register_cpu_notifier() to fix the problem.

Cc: Paolo Bonzini pbonz...@redhat.com
Cc: Christoffer Dall christoffer.d...@linaro.org
Cc: Srivatsa S. Bhat srivatsa.b...@linux.vnet.ibm.com
Cc: Rafael J. Wysocki rafael.j.wyso...@intel.com
Signed-off-by: Ming Lei tom.leim...@gmail.com
---
 virt/kvm/arm/arch_timer.c |2 +-
 virt/kvm/arm/vgic.c   |2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/virt/kvm/arm/arch_timer.c b/virt/kvm/arm/arch_timer.c
index 5081e80..22fa819 100644
--- a/virt/kvm/arm/arch_timer.c
+++ b/virt/kvm/arm/arch_timer.c
@@ -277,7 +277,7 @@ int kvm_timer_hyp_init(void)
 
host_vtimer_irq = ppi;
 
-   err = register_cpu_notifier(kvm_timer_cpu_nb);
+   err = __register_cpu_notifier(kvm_timer_cpu_nb);
if (err) {
kvm_err(Cannot register timer CPU notifier\n);
goto out_free;
diff --git a/virt/kvm/arm/vgic.c b/virt/kvm/arm/vgic.c
index 8ca405c..47b2983 100644
--- a/virt/kvm/arm/vgic.c
+++ b/virt/kvm/arm/vgic.c
@@ -1496,7 +1496,7 @@ int kvm_vgic_hyp_init(void)
goto out;
}
 
-   ret = register_cpu_notifier(vgic_cpu_nb);
+   ret = __register_cpu_notifier(vgic_cpu_nb);
if (ret) {
kvm_err(Cannot register vgic CPU notifier\n);
goto out_free_irq;
-- 
1.7.9.5

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