[PATCH 2/7] omap: mailbox: check for NULL nb in mailbox_put

[PATCH 2/7] omap: mailbox: check for NULL nb in mailbox_put

[Suman Anna]

The mailbox_put function must check the notifier block for
NULL before trying to unregister it.

Signed-off-by: Fernando Guzman Lugo <lugo.fernando@gmail.com>
Signed-off-by: Suman Anna <s-anna@ti.com>
---
 arch/arm/plat-omap/mailbox.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/arm/plat-omap/mailbox.c b/arch/arm/plat-omap/mailbox.c
index 42377ef..5fb4027 100644
--- a/arch/arm/plat-omap/mailbox.c
+++ b/arch/arm/plat-omap/mailbox.c
@@ -356,7 +356,8 @@ EXPORT_SYMBOL(omap_mbox_get);
 
 void omap_mbox_put(struct omap_mbox *mbox, struct notifier_block *nb)
 {
-	blocking_notifier_chain_unregister(&mbox->notifier, nb);
+	if (nb)
+		blocking_notifier_chain_unregister(&mbox->notifier, nb);
 	omap_mbox_fini(mbox);
 }
 EXPORT_SYMBOL(omap_mbox_put);
-- 
1.8.2

Re: [PATCH 2/7] omap: mailbox: check for NULL nb in mailbox_put

[Russ Dill]

On Fri, Jun 7, 2013 at 6:57 PM, Suman Anna <s-anna@ti.com> wrote:
> The mailbox_put function must check the notifier block for
> NULL before trying to unregister it.

I'm going to nack this one. Why must it check for NULL? None of the
callers pass a NULL argument and blocking_notifier_chain_unregister
handles a NULL nb argument just fine.

> Signed-off-by: Fernando Guzman Lugo <lugo.fernando@gmail.com>
> Signed-off-by: Suman Anna <s-anna@ti.com>
> ---
>  arch/arm/plat-omap/mailbox.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/arch/arm/plat-omap/mailbox.c b/arch/arm/plat-omap/mailbox.c
> index 42377ef..5fb4027 100644
> --- a/arch/arm/plat-omap/mailbox.c
> +++ b/arch/arm/plat-omap/mailbox.c
> @@ -356,7 +356,8 @@ EXPORT_SYMBOL(omap_mbox_get);
>
>  void omap_mbox_put(struct omap_mbox *mbox, struct notifier_block *nb)
>  {
> -       blocking_notifier_chain_unregister(&mbox->notifier, nb);
> +       if (nb)
> +               blocking_notifier_chain_unregister(&mbox->notifier, nb);
>         omap_mbox_fini(mbox);
>  }
>  EXPORT_SYMBOL(omap_mbox_put);
> --
> 1.8.2
>
> --
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Re: [PATCH 2/7] omap: mailbox: check for NULL nb in mailbox_put

[Suman Anna]

Russ,

On 06/08/2013 01:46 PM, Russ Dill wrote:
> On Fri, Jun 7, 2013 at 6:57 PM, Suman Anna <s-anna@ti.com> wrote:
>> The mailbox_put function must check the notifier block for
>> NULL before trying to unregister it.
> 
> I'm going to nack this one. Why must it check for NULL? None of the
> callers pass a NULL argument and blocking_notifier_chain_unregister
> handles a NULL nb argument just fine.

Thanks for the review. It should have been done differently, which is to
print an error trace if the passed in arguments are NULL. Anyway, I will
drop this since I expect this function to go away once this is adapted
to the new framework.

regards
Suman

> 
>> Signed-off-by: Fernando Guzman Lugo <lugo.fernando@gmail.com>
>> Signed-off-by: Suman Anna <s-anna@ti.com>
>> ---
>>  arch/arm/plat-omap/mailbox.c | 3 ++-
>>  1 file changed, 2 insertions(+), 1 deletion(-)
>>
>> diff --git a/arch/arm/plat-omap/mailbox.c b/arch/arm/plat-omap/mailbox.c
>> index 42377ef..5fb4027 100644
>> --- a/arch/arm/plat-omap/mailbox.c
>> +++ b/arch/arm/plat-omap/mailbox.c
>> @@ -356,7 +356,8 @@ EXPORT_SYMBOL(omap_mbox_get);
>>
>>  void omap_mbox_put(struct omap_mbox *mbox, struct notifier_block *nb)
>>  {
>> -       blocking_notifier_chain_unregister(&mbox->notifier, nb);
>> +       if (nb)
>> +               blocking_notifier_chain_unregister(&mbox->notifier, nb);
>>         omap_mbox_fini(mbox);
>>  }
>>  EXPORT_SYMBOL(omap_mbox_put);
>> --
>> 1.8.2
>>
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-omap" in
>> the body of a message to majordomo@vger.kernel.org
>> More majordomo info at  http://vger.kernel.org/majordomo-info.html