Re: [PATCH] ACPI/APEI: Unlock apei_iomaps_lock on error path

[Keir Fraser <keir.xen@gmail.com>]

On 22/03/2013 08:15, "Jan Beulich" <JBeulich@suse.com> wrote:

>>>> On 22.03.13 at 00:19, Andrew Cooper <andrew.cooper3@citrix.com> wrote:
>> This causes deadlocks during early boot on hardware with broken/buggy APEI
>> implementations, such as a Dell Poweredge 2950 with the latest currently
>> available BIOS.
>> 
>> Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
>> 
>> diff -r 7babbd46586b -r 6a952c14c4dc xen/drivers/acpi/apei/apei-io.c
>> --- a/xen/drivers/acpi/apei/apei-io.c
>> +++ b/xen/drivers/acpi/apei/apei-io.c
>> @@ -147,12 +147,15 @@ static void __init apei_post_unmap(paddr
>> spin_lock_irqsave(&apei_iomaps_lock, flags);
>> map = __apei_find_iomap(paddr, size);
>> if (!map)
>> -  return;
>> +  goto err;
>>  
>> list_del(&map->list);
>> spin_unlock_irqrestore(&apei_iomaps_lock, flags);
>>  
>> xfree(map);
>> + return;
>> +err:
>> + spin_unlock_irqrestore(&apei_iomaps_lock, flags);
>>  }
>>  
>>  /* In NMI handler, should set silent = 1 */
> 
> I'd prefer doing this slightly differently:

In this case, agreed.

 -- Keir

> --- a/xen/drivers/acpi/apei/apei-io.c
> +++ b/xen/drivers/acpi/apei/apei-io.c
> @@ -146,10 +146,8 @@ static void __init apei_post_unmap(paddr
>  
> spin_lock_irqsave(&apei_iomaps_lock, flags);
> map = __apei_find_iomap(paddr, size);
> - if (!map)
> -  return;
> -
> - list_del(&map->list);
> + if (map)
> +  list_del(&map->list);
> spin_unlock_irqrestore(&apei_iomaps_lock, flags);
>  
> xfree(map);
> 
> Jan
>