svn commit: r366144 - head/usr.sbin/pwm

[Andriy Gapon]

Author: avg
Date: Fri Sep 25 07:55:08 2020
New Revision: 366144
URL: https://svnweb.freebsd.org/changeset/base/366144

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

Modified:
  head/usr.sbin/pwm/pwm.c

Modified: head/usr.sbin/pwm/pwm.c
==============================================================================
--- head/usr.sbin/pwm/pwm.c	Fri Sep 25 07:54:38 2020	(r366143)
+++ head/usr.sbin/pwm/pwm.c	Fri Sep 25 07:55:08 2020	(r366144)
@@ -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");