If the configured number of samples was close to MAXSAMPLES,
the samples buffer could be overrun:
- by 1, because of off-by-one in the condition (samples > arg_samples_len),
and
- by many in case of an overrun, because the number of samples to
capture was increased, instead of being decreased.
Simplify things by converting to a normal for-loop.
In store.c: change buffer size from 4095 to 4096. 4095 is a strange
number.
log_uptime();
/* main program loop */
- while (!exiting) {
+ for (samples = 0; !exiting && samples < arg_samples_len; samples++) {
int res;
double sample_stop;
struct timespec req;
NULL);
/* wait for /proc to become available, discarding samples */
- if (!(graph_start > 0.0))
+ if (graph_start <= 0.0)
log_uptime();
else
log_sample(samples);
* we'll lose all the missed samples and overrun our total
* time
*/
- if ((newint_ns > 0) || (newint_s > 0)) {
+ if (newint_ns > 0 || newint_s > 0) {
req.tv_sec = newint_s;
req.tv_nsec = newint_ns;
} else {
overrun++;
/* calculate how many samples we lost and scrap them */
- arg_samples_len = arg_samples_len + ((int)(newint_ns / interval));
+ arg_samples_len -= (int)(newint_ns / interval);
}
-
- samples++;
-
- if (samples > arg_samples_len)
- break;
-
}
/* do some cleanup, close fd's */
void log_sample(int sample) {
static int vmstat;
static int schedstat;
- char buf[4095];
+ char buf[4096];
char key[256];
char val[256];
char rt[256];