[Devel] [PATCH v3 4/9] user namespace support for upstream containers

[Glauber Costa]

On 05/11/2013 04:14 AM, Igor M Podlesny wrote:
> On 30 April 2013 13:16, Glauber Costa <glommer at openvz.org> wrote:
>> @@ -576,7 +765,9 @@ int ct_do_open(vps_handler *h, vps_param *param)
>>  {
>>         int ret;
>>         char path[STR_SIZE];
>> +       char upath[STR_SIZE];
>>         struct stat st;
>> +       unsigned long *local_uid = param->res.misc.local_uid;
>>
>>         ret = container_init();
>>         if (ret) {
>> @@ -592,6 +783,9 @@ int ct_do_open(vps_handler *h, vps_param *param)
>>         if (snprintf(path, sizeof(path), "/proc/%d/ns/pid", getpid()) < 0)
>>                 return VZ_RESOURCE_ERROR;
>>
>> +       if (snprintf(upath, sizeof(upath), "/proc/%d/ns/user", getpid()) < 0)
>> +               return VZ_RESOURCE_ERROR;
>> +
> 
>    It might have sense to compare return code not with 0, but
> sizeof(upath), since "... The functions snprintf() and vsnprintf() do
> not write more than size bytes (including the terminating null byte
> ('\0')). If the output was truncated due to this limit then the return
> value is the number of characters (excluding the terminating null
> byte) which would have been written to the final string if enough
> space had been available. Thus, a return value of size or more means
> that the output was truncated. ..."
> 

Doesn't matter that much, because this situation is impossible, given
that getpid() will always return a bounded value and we know the rest of
the string. So it either fails, or it succeeds in its fullest.

But that is all the same to me.