Re: [dpdk-dev] [PATCH] test: fix division by zero

["Min Hu (Connor)" <humin29@huawei.com>]

在 2021/5/13 0:53, Bruce Richardson 写道:
> On Fri, Apr 23, 2021 at 03:35:30PM +0800, Min Hu (Connor) wrote:
>> Variable i is used as a denominator which may be zero, and
>> this may result in segmentation fault.
>>
>> This patch fixed it.
>>
>> Fixes: 948bc3d6d095 ("test: add reciprocal based division")
>> Cc: stable@dpdk.org
>>
>> Signed-off-by: Min Hu (Connor) <humin29@huawei.com>
>> ---
>>   app/test/test_reciprocal_division_perf.c | 5 +++--
>>   1 file changed, 3 insertions(+), 2 deletions(-)
>>
>> diff --git a/app/test/test_reciprocal_division_perf.c b/app/test/test_reciprocal_division_perf.c
>> index a7be8aa..2647308 100644
>> --- a/app/test/test_reciprocal_division_perf.c
>> +++ b/app/test/test_reciprocal_division_perf.c
>> @@ -143,7 +143,7 @@ test_reciprocal_division_perf(void)
>>   					"result %"PRIu64"",
>>   					nresult_u64, rresult_u64);
>>   			result = 1;
>> -			break;
>> +			goto err;
>>   		}
>>   	}
>>   
>> @@ -182,7 +182,7 @@ test_reciprocal_division_perf(void)
>>   					dividend_u64, divisor_u64,
>>   					nresult_u64, rresult_u64);
>>   			result = 1;
>> -			break;
>> +			goto err;
>>   		}
>>   	}
>>   	printf("64bit Division results:\n");
>> @@ -195,6 +195,7 @@ test_reciprocal_division_perf(void)
>>   	printf("Cycles per division(reciprocal) : %3.2f\n",
>>   			((double)tot_cyc_r)/i);
>>   
>> +err:
>>   	return result;
>>   }
>>   
> This looks correct as far as it goes, but I believe the same fix is needed
> at lines 66 and 106 too.
> 
> One other thing I note is that currently the test will move on to the
> next test case on failure, due to break, but using the goto will change
> that behaviour. Therefore, I wonder if a better fix is to skip the
> printouts if i == 0 in each case?
> 
Good point, fixed in v2, thanks Bruce.
> /Bruce
> .
>