svn commit: r324628 - head/sys/compat/linux

[Tijl Coosemans]

Author: tijl
Date: Sun Oct 15 16:03:45 2017
New Revision: 324628
URL: https://svnweb.freebsd.org/changeset/base/324628

Log:
  Use sizeof instead of strlen on string constants.  The compiler doesn't
  optimise the strlen calls away with -ffreestanding.

Modified:
  head/sys/compat/linux/linux_util.c

Modified: head/sys/compat/linux/linux_util.c
==============================================================================
--- head/sys/compat/linux/linux_util.c	Sun Oct 15 14:03:53 2017	(r324627)
+++ head/sys/compat/linux/linux_util.c	Sun Oct 15 16:03:45 2017	(r324628)
@@ -128,32 +128,31 @@ linux_driver_get_major_minor(const char *node, int *ma
 {
 	struct device_element *de;
 	unsigned long devno;
+	size_t sz;
 
 	if (node == NULL || major == NULL || minor == NULL)
 		return 1;
 
-	if (strlen(node) > strlen("pts/") &&
-	    strncmp(node, "pts/", strlen("pts/")) == 0) {
+	sz = sizeof("pts/") - 1;
+	if (strncmp(node, "pts/", sz) == 0 && node[sz] != '\0') {
 		/*
 		 * Linux checks major and minors of the slave device
 		 * to make sure it's a pty device, so let's make him
 		 * believe it is.
 		 */
-		devno = strtoul(node + strlen("pts/"), NULL, 10);
+		devno = strtoul(node + sz, NULL, 10);
 		*major = 136 + (devno / 256);
 		*minor = devno % 256;
-
 		return (0);
 	}
 
-	if ((strlen(node) > strlen("drm/") &&
-	    strncmp(node, "drm/", strlen("drm/")) == 0) ) {
-		devno = strtoul(node + strlen("drm/"), NULL, 10);
+	sz = sizeof("drm/") - 1;
+	if (strncmp(node, "drm/", sz) == 0 && node[sz] != '\0') {
+		devno = strtoul(node + sz, NULL, 10);
 		*major = 226 + (devno / 256);
 		*minor = devno % 256;
 		return (0);
 	}
-
 
 	TAILQ_FOREACH(de, &devices, list) {
 		if (strcmp(node, de->entry.bsd_device_name) == 0) {