Re: + kvm-ia64-dereference-of-null-pointer-in-set_pal_result.patch added to -mm tree

[Avi Kivity <avi@redhat.com>]

On 01/13/2010 11:32 AM, Andrew Morton wrote:
> On Wed, 13 Jan 2010 11:22:39 +0200 Avi Kivity<avi@redhat.com>  wrote:
>
>    
>> On 01/13/2010 12:11 AM, akpm@linux-foundation.org wrote:
>>      
>>> Subject: kvm/ia64: dereference of NULL pointer in set_pal_result()
>>> From: Roel Kluin<roel.kluin@gmail.com>
>>>
>>> Do not dereference a NULL pointer
>>>
>>> diff -puN arch/ia64/kvm/kvm_fw.c~kvm-ia64-dereference-of-null-pointer-in-set_pal_result arch/ia64/kvm/kvm_fw.c
>>> --- a/arch/ia64/kvm/kvm_fw.c~kvm-ia64-dereference-of-null-pointer-in-set_pal_result
>>> +++ a/arch/ia64/kvm/kvm_fw.c
>>> @@ -75,9 +75,11 @@ static void set_pal_result(struct kvm_vc
>>>    	struct exit_ctl_data *p;
>>>
>>>    	p = kvm_get_exit_data(vcpu);
>>> -	if (p&&   p->exit_reason == EXIT_REASON_PAL_CALL) {
>>> +	if (!p)
>>> +		return;
>>> +	if (p->exit_reason == EXIT_REASON_PAL_CALL) {
>>>    		p->u.pal_data.ret = result;
>>> -		return ;
>>> +		return;
>>>    	}
>>>    	INIT_PAL_STATUS_UNIMPLEMENTED(p->u.pal_data.ret);
>>>    }
>>>
>>>        
>>
>> kvm_get_exit_data() cannot return a NULL pointer.
>>      
> In that case set_pal_result() doesn't need to test for that.
>
> Roel looks for code along the lines of
>
> 	if (p)
> 		...
>
> 	*p;
>    

I see.  I think it's worthwhile to look deeper rather than converting 
things mechanically.  After all, the code may have actually worked 
before the patch.

-- 
error compiling committee.c: too many arguments to function