1 files changed, 58 insertions, 14 deletions

diff --git a/lib/string.c b/lib/string.c
index b19b87af65a3..a1cdcfcc42d0 100644
--- a/lib/string.c
+++ b/lib/string.c
@@ -246,13 +246,17 @@ EXPORT_SYMBOL(strlcat);
 #undef strcmp
 int strcmp(const char *cs, const char *ct)
 {
-        signed char __res;
+        unsigned char c1, c2;
 
         while (1) {
-                if ((__res = *cs - *ct++) != 0 || !*cs++)
+                c1 = *cs++;
+                c2 = *ct++;
+                if (c1 != c2)
+                        return c1 < c2 ? -1 : 1;
+                if (!c1)
                         break;
         }
-        return __res;
+        return 0;
 }
 EXPORT_SYMBOL(strcmp);
 #endif
@@ -266,14 +270,18 @@ EXPORT_SYMBOL(strcmp);
  */
 int strncmp(const char *cs, const char *ct, size_t count)
 {
-        signed char __res = 0;
+        unsigned char c1, c2;
 
         while (count) {
-                if ((__res = *cs - *ct++) != 0 || !*cs++)
+                c1 = *cs++;
+                c2 = *ct++;
+                if (c1 != c2)
+                        return c1 < c2 ? -1 : 1;
+                if (!c1)
                         break;
                 count--;
         }
-        return __res;
+        return 0;
 }
 EXPORT_SYMBOL(strncmp);
 #endif
@@ -330,20 +338,34 @@ EXPORT_SYMBOL(strnchr);
 #endif
 
 /**
- * strstrip - Removes leading and trailing whitespace from @s.
+ * skip_spaces - Removes leading whitespace from @str.
+ * @str: The string to be stripped.
+ *
+ * Returns a pointer to the first non-whitespace character in @str.
+ */
+char *skip_spaces(const char *str)
+{
+        while (isspace(*str))
+                ++str;
+        return (char *)str;
+}
+EXPORT_SYMBOL(skip_spaces);
+
+/**
+ * strim - Removes leading and trailing whitespace from @s.
  * @s: The string to be stripped.
  *
  * Note that the first trailing whitespace is replaced with a %NUL-terminator
  * in the given string @s. Returns a pointer to the first non-whitespace
  * character in @s.
  */
-char *strstrip(char *s)
+char *strim(char *s)
 {
         size_t size;
         char *end;
 
+        s = skip_spaces(s);
         size = strlen(s);
-
         if (!size)
                 return s;
 
@@ -352,12 +374,9 @@ char *strstrip(char *s)
                 end--;
         *(end + 1) = '\0';
 
-        while (*s && isspace(*s))
-                s++;
-
         return s;
 }
-EXPORT_SYMBOL(strstrip);
+EXPORT_SYMBOL(strim);
 
 #ifndef __HAVE_ARCH_STRLEN
 /**
@@ -648,7 +667,7 @@ EXPORT_SYMBOL(memscan);
  */
 char *strstr(const char *s1, const char *s2)
 {
-        int l1, l2;
+        size_t l1, l2;
 
         l2 = strlen(s2);
         if (!l2)
@@ -665,6 +684,31 @@ char *strstr(const char *s1, const char *s2)
 EXPORT_SYMBOL(strstr);
 #endif
 
+#ifndef __HAVE_ARCH_STRNSTR
+/**
+ * strnstr - Find the first substring in a length-limited string
+ * @s1: The string to be searched
+ * @s2: The string to search for
+ * @len: the maximum number of characters to search
+ */
+char *strnstr(const char *s1, const char *s2, size_t len)
+{
+        size_t l1 = len, l2;
+
+        l2 = strlen(s2);
+        if (!l2)
+                return (char *)s1;
+        while (l1 >= l2) {
+                l1--;
+                if (!memcmp(s1, s2, l2))
+                        return (char *)s1;
+                s1++;
+        }
+        return NULL;
+}
+EXPORT_SYMBOL(strnstr);
+#endif
+
 #ifndef __HAVE_ARCH_MEMCHR
 /**
  * memchr - Find a character in an area of memory.