[CRIU] [PATCH] posix-timer: take into account that sival_ptr can be NULL (v2)

[Pavel Emelyanov]

On 02/18/2014 03:36 PM, Andrew Vagin wrote:
> On Tue, Feb 18, 2014 at 03:23:02PM +0400, Pavel Emelyanov wrote:
>> On 02/18/2014 02:07 PM, Andrey Vagin wrote:
>>> ID: 0
>>> signal: 26/          (null)
>>> notify: signal/pid.5954
>>> ClockID: 1
>>>
>>> fscanf "%p" doesn't handle "(null)".
>>>
>>> https://bugzilla.openvz.org/show_bug.cgi?id=2894
>>>
>>> v2: make the original scanf be %d/%s and then additionally
>>>     parse the obtained string
>>>
>>> Signed-off-by: Andrey Vagin <avagin at openvz.org>
>>> ---
>>>  proc_parse.c | 12 ++++++++++--
>>>  1 file changed, 10 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/proc_parse.c b/proc_parse.c
>>> index 26dd9c4..5ecdc22 100644
>>> --- a/proc_parse.c
>>> +++ b/proc_parse.c
>>> @@ -1277,16 +1277,17 @@ int parse_posix_timers(pid_t pid, struct proc_posix_timers_stat *args)
>>>  	}
>>>  
>>>  	while (1) {
>>> +		char pbuf[17]; /* 16 + eol */
>>>  		timer = xzalloc(sizeof(struct proc_posix_timer));
>>>  		if (timer == NULL)
>>>  			goto err;
>>>  
>>>  		ret = fscanf(file, "ID: %ld\n"
>>> -				   "signal: %d/%p\n"
>>> +				   "signal: %d/%16s\n"
>>>  				   "notify: %6[a-z]/%3[a-z].%d\n"
>>>  				   "ClockID: %d\n",
>>>  				&timer->spt.it_id,
>>> -				&timer->spt.si_signo, &timer->spt.sival_ptr,
>>> +				&timer->spt.si_signo, pbuf,
>>>  				sigpid, tidpid, &pid_t,
>>>  				&timer->spt.clock_id);
>>>  		if (ret != 7) {
>>> @@ -1297,6 +1298,13 @@ int parse_posix_timers(pid_t pid, struct proc_posix_timers_stat *args)
>>>  			goto err;
>>>  		}
>>>  
>>> +		timer->spt.sival_ptr = NULL;
>>> +		if (sscanf(pbuf, "%p", &timer->spt.sival_ptr) != 1 &&
>>> +		    strstr(pbuf, "(null)") == NULL) {
>>
>> The strstr is overkill, better use strncmp for that case.
> 
> It will look like this
> 
> strncmp(pbuf, "          (null)", 16)

This one is sucks the least :)

> or
> strlen(pbuf) == 16 && strncmp(pbuf + 10, "(null)", 6)
> 
>>
>>> +			xfree(timer);
>>> +			goto err;
>>> +		}
>>> +
>>>  		if ( tidpid[0] == 't') {
>>>  			timer->spt.it_sigev_notify = SIGEV_THREAD_ID;
>>>  		} else {
>>>
>>
>>
> .
>