Re: [PATCH] arch: metag: kernel: dma.c: check 'pud' whether is NULL in dma_alloc_init()

[Chen Gang <gang.chen-bOixZGp5f+dBDgjK7y7TUQ@public.gmane.org>]

On 11/14/2013 05:18 PM, James Hogan wrote:
> On Thursday 14 November 2013 16:11:21 Chen Gang wrote:
>> Like another p?d_alloc(), pud_alloc() also may fail, so need check it.
>>
>> Signed-off-by: Chen Gang <gang.chen-bOixZGp5f+dBDgjK7y7TUQ@public.gmane.org>
> 
> NAK.
> 
> pud_alloc folds to pud_offset on Meta so it cannot fail.
> 

If so, can pmd_alloc() be fail?

I checked the related definitions, it seems a little complex, can we
assume p?d_alloc() are in the same condition?


Thanks.

> Cheers
> James
> 
>> ---
>>  arch/metag/kernel/dma.c |    5 +++++
>>  1 files changed, 5 insertions(+), 0 deletions(-)
>>
>> diff --git a/arch/metag/kernel/dma.c b/arch/metag/kernel/dma.c
>> index db589ad..e6cf39b 100644
>> --- a/arch/metag/kernel/dma.c
>> +++ b/arch/metag/kernel/dma.c
>> @@ -398,6 +398,11 @@ static int __init dma_alloc_init(void)
>>  		int offset = pgd_index(CONSISTENT_START);
>>  		pgd = pgd_offset(&init_mm, CONSISTENT_START);
>>  		pud = pud_alloc(&init_mm, pgd, CONSISTENT_START);
>> +		if (!pud) {
>> +			pr_err("%s: no pud tables\n", __func__);
>> +			ret = -ENOMEM;
>> +			break;
>> +		}
>>  		pmd = pmd_alloc(&init_mm, pud, CONSISTENT_START);
>>  		if (!pmd) {
>>  			pr_err("%s: no pmd tables\n", __func__);
> 
> 


-- 
Chen Gang
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