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pwm(8): fix potential duty overflow, use unsigneds for period and duty

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For a long period value and the duty specified as a percentage,
there could be an overflow.
Using unsigned integers aligns the code with struct pwm_state and allows
to safely use periods up to 4 seconds where supported by drivers.

MFC after:	2 weeks
This commit is contained in:
Andriy Gapon 2020-09-25 07:55:08 +00:00
parent 31b0753da3
commit a4f28d4296
1 changed files with 7 additions and 7 deletions
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14
usr.sbin/pwm/pwm.c
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@ -75,7 +75,7 @@ main(int argc, char *argv[])
{
struct pwm_state state;
int fd;
int period, duty;
u_int period, duty;
int action, ch;
cap_rights_t right_ioctl;
const unsigned long pwm_ioctls[] = {PWMGETSTATE, PWMSETSTATE};
@ -108,16 +108,16 @@ main(int argc, char *argv[])
if (action & PWM_SHOW_CONFIG)
usage();
action |= PWM_PERIOD;
period = strtol(optarg, NULL, 10);
period = strtoul(optarg, NULL, 10);
break;
case 'd':
if (action & PWM_SHOW_CONFIG)
usage();
action |= PWM_DUTY;
duty = strtol(optarg, &percent, 10);
duty = strtoul(optarg, &percent, 10);
if (*percent == '%') {
if (duty < 0 || duty > 100) {
fprintf(stderr,
if (duty > 100) {
fprintf(stderr,
"Invalid duty percentage\n");
usage();
}
@ -185,11 +185,11 @@ main(int argc, char *argv[])
state.period = period;
if (action & PWM_DUTY) {
if (*percent != '\0')
state.duty = state.period * duty / 100;
state.duty = (uint64_t)state.period * duty / 100;
else
state.duty = duty;
}
if (ioctl(fd, PWMSETSTATE, &state) == -1) {
fprintf(stderr,
"Cannot configure the pwm controller\n");