Re: [PATCH 3/7] crypto: testmgr: fix warning

[Jarod Wilson <jarod@redhat.com>]

On 10/19/09 9:52 AM, Jiri Kosina wrote:
> On Mon, 19 Oct 2009, Felipe Contreras wrote:
>
>> crypto/testmgr.c: In function ?test_cprng?:
>> crypto/testmgr.c:1204: warning: ?err? may be used uninitialized in this function
>>
>> Signed-off-by: Felipe Contreras<felipe.contreras@gmail.com>
>> ---
>>   crypto/testmgr.c |    2 +-
>>   1 files changed, 1 insertions(+), 1 deletions(-)
>>
>> diff --git a/crypto/testmgr.c b/crypto/testmgr.c
>> index 6d5b746..1f2357b 100644
>> --- a/crypto/testmgr.c
>> +++ b/crypto/testmgr.c
>> @@ -1201,7 +1201,7 @@ static int test_cprng(struct crypto_rng *tfm, struct cprng_testvec *template,
>>   		      unsigned int tcount)
>>   {
>>   	const char *algo = crypto_tfm_alg_driver_name(crypto_rng_tfm(tfm));
>> -	int err, i, j, seedsize;
>> +	int err = 0, i, j, seedsize;
>>   	u8 *seed;
>>   	char result[32];
>
> As it is not obvious to me immediately why/whether tcount couldn't be zero
> (which would cause uninitialized use of 'err'), I am not merging this
> through trivial tree. Herbert?

I believe I'm the guilty party who wrote the code in question. 
Initializing err to 0 isn't correct. tcount should always be at least 1, 
if its 0, test_cprng has been called with invalid parameters. I believe 
err would best be initialized to -EINVAL, lest the caller think they 
were successful.

-- 
Jarod Wilson
jarod@redhat.com