Re: [dpdk-dev] [PATCH] bpf: delete meaningless code

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

在 2021/4/21 19:43, Ananyev, Konstantin 写道:
>>
>> 'rd->u.max = rd->u.max' is meaningless which should be deleted.
>>
>> This patch fixed it.
>>
>> Fixes: 8021917293d0 ("bpf: add extra validation for input BPF program")
>> Cc: stable@dpdk.org
> 
> As I remember, I did it on purpose.
> Some old (but still supported) version of clang complained
> about unitialized variable.

Well, how about like this ?
		uint64_t tmp = rd->u.max;
		if (op == BPF_MOD)
			tmp = RTE_MIN(tmp, tmp - 1);
		rd->u.max = tmp;

> 
>> Signed-off-by: Min Hu (Connor) <humin29@huawei.com>
>> ---
>>   lib/librte_bpf/bpf_validate.c | 2 --
>>   1 file changed, 2 deletions(-)
>>
>> diff --git a/lib/librte_bpf/bpf_validate.c b/lib/librte_bpf/bpf_validate.c
>> index 9214f15..c5ad951 100644
>> --- a/lib/librte_bpf/bpf_validate.c
>> +++ b/lib/librte_bpf/bpf_validate.c
>> @@ -517,8 +517,6 @@ eval_divmod(uint32_t op, struct bpf_reg_val *rd, struct bpf_reg_val *rs,
>>   	} else {
>>   		if (op == BPF_MOD)
>>   			rd->u.max = RTE_MIN(rd->u.max, rs->u.max - 1);
>> -		else
>> -			rd->u.max = rd->u.max;
>>   		rd->u.min = 0;
>>   	}
>>
>> --
>> 2.7.4
> 
> .
>