Re: [PATCH 4/4] tracing/filters: Fix MATCH_EBD_ONLY filter matching

[Li Zefan <lizf@cn.fujitsu.com>]

>>  static int regex_match_end(char *str, struct regex *r, int len)
>>  {
>> -	char *ptr = strstr(str, r->pattern);
>> +	int strlen = len - 1;
>>  
>> -	if (ptr && (ptr[r->len] == 0))
>> +	if (strlen >= r->len &&
>> +	    !memcmp(str + strlen - r->len, r->pattern, r->len))
> 
> Please use memcmp() == 0, I've seen too many bugs with !*cmp as well as
> with *cmp, because humans tend to think instinctively when reading this
> that ! is not a match. With "== 0" we think that "==" is a match and
>  "!=" is a miss.
> 

Though I sometimes don't care much about this, I do
think memcmp() == 0 is better.