[CRIU] [PATCH v2 1/2] util: xatol() and xatoi() helpers introduced

[Stanislav Kinsburskiy]

23.09.2017 00:30, Andrei Vagin пишет:
> On Wed, Sep 13, 2017 at 04:48:50PM +0300, Stanislav Kinsburskiy wrote:
>> These helpers are safe versions of atol() and atoi() respectively.
>> And they check for overflow and NAN errors
>>
>> Signed-off-by: Stanislav Kinsburskiy <skinsbursky at virtuozzo.com>
>> ---
>>  criu/include/util.h |    3 +++
>>  criu/util.c         |   38 ++++++++++++++++++++++++++++++++++++++
>>  2 files changed, 41 insertions(+)
>>
>> diff --git a/criu/include/util.h b/criu/include/util.h
>> index 1fc20db..20684cc 100644
>> --- a/criu/include/util.h
>> +++ b/criu/include/util.h
>> @@ -280,6 +280,9 @@ void tcp_cork(int sk, bool on);
>>  
>>  const char *ns_to_string(unsigned int ns);
>>  
>> +int xatol(const char *string, long *number);
>> +int xatoi(const char *string, int *number);
>> +
>>  char *xstrcat(char *str, const char *fmt, ...)
>>  	__attribute__ ((__format__ (__printf__, 2, 3)));
>>  char *xsprintf(const char *fmt, ...)
>> diff --git a/criu/util.c b/criu/util.c
>> index b5a161f..7d60617 100644
>> --- a/criu/util.c
>> +++ b/criu/util.c
>> @@ -58,6 +58,44 @@
>>  
>>  #define VMA_OPT_LEN	128
>>  
>> +static int xatol_base(const char *string, long *number, int base)
>> +{
>> +	char *endptr;
>> +	long nr;
>> +
>> +	errno = 0;
>> +	nr = strtol(string, &endptr, base);
>> +	if ((errno == ERANGE && (nr == LONG_MAX || nr == LONG_MIN))
>> +			|| (errno != 0 && nr == 0)) {
>> +		pr_perror("failed to convert string");
> 
> It is better to print this string in a error message
> 


Well,on the other hand how we can distinguish between this error case above and EINVAL, returned below, when string is not a number?


>> +		return -EINVAL;
>> +	}
>> +
>> +	if ((endptr == string) || (*endptr != '\0')) {
>> +		pr_err("String is not a number: '%s'\n", string);
>> +		return -EINVAL;
>> +	}
>> +	*number = nr;
>> +	return 0;
>> +}
>> +
>> +int xatol(const char *string, long *number)
>> +{
>> +	return xatol_base(string, number, 10);
>> +}
>> +
>> +
>> +int xatoi(const char *string, int *number)
>> +{
>> +	long tmp;
>> +	int err;
>> +
>> +	err = xatol(string, &tmp);
> 
> Should we check that tmp is in [INT_MIN, INT_MAX]?


Well, looks like we shouldn't. Atoi will return interger even if string contains long.


>> +	if (!err)
>> +		*number = (int)tmp;
>> +	return err;
>> +}
>> +
>>  /*
>>   * This function reallocates passed str pointer.
>>   * It means:
>>
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