phc2sys: Fix lower bound value of update_rate

Following command produces unexpected update rate.
 # phc2sys -s eth0 -q -m -O0 -R1.0842021724855044e-19
This is caused by wrong validation of phc_interval related to
significant digits of double precision and phc_interval_tp.tv_sec
overflow.

To avoid these unwanted trouble, this patch limits lower bound of
phc_rate to 1e-9.
There is no profound meaning in the lower bound value. I just think
it's enough to actual use and it doesn't cause phc_interval_tp.tv_sec
overflow in not only 64bit environment but also 32bit environment.
Thereby, messy validation of phc_interval is no longer needed.

Signed-off-by: Ken ICHIKAWA <ichikawa.ken@jp.fujitsu.com>
master
Ken ICHIKAWA 2013-09-04 12:04:37 +09:00 committed by Richard Cochran
parent 5bf265e860
commit b943ea2fba
1 changed files with 1 additions and 9 deletions

View File

@ -634,17 +634,9 @@ int main(int argc, char *argv[])
return -1; return -1;
break; break;
case 'R': case 'R':
if (get_arg_val_d(c, optarg, &phc_rate, 0.0, DBL_MAX)) if (get_arg_val_d(c, optarg, &phc_rate, 1e-9, DBL_MAX))
return -1; return -1;
phc_interval = 1.0 / phc_rate; phc_interval = 1.0 / phc_rate;
/* phc_interval will be assigned to a time_t variable. */
/* check if that occurs overflow. */
if ((sizeof(time_t) == 8 && phc_interval > INT64_MAX) ||
(sizeof(time_t) == 4 && phc_interval > INT32_MAX)) {
fprintf(stderr,
"-R: %s is too small\n", optarg);
return -1;
}
break; break;
case 'N': case 'N':
if (get_arg_val_i(c, optarg, &phc_readings, 1, INT_MAX)) if (get_arg_val_i(c, optarg, &phc_readings, 1, INT_MAX))