1 files changed, 71 insertions, 3 deletions

diff --git a/lib/string.c b/lib/string.c
index 01fad9b203e1..e5878de4f101 100644
--- a/lib/string.c
+++ b/lib/string.c
@@ -22,7 +22,10 @@
 #include <linux/types.h>
 #include <linux/string.h>
 #include <linux/ctype.h>
-#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/export.h>
+#include <linux/bug.h>
+#include <linux/errno.h>
 
 #ifndef __HAVE_ARCH_STRNICMP
 /**
@@ -360,7 +363,6 @@ char *strim(char *s)
 	size_t size;
 	char *end;
 
-	s = skip_spaces(s);
 	size = strlen(s);
 	if (!size)
 		return s;
@@ -370,7 +372,7 @@ char *strim(char *s)
 		end--;
 	*(end + 1) = '\0';
 
-	return s;
+	return skip_spaces(s);
 }
 EXPORT_SYMBOL(strim);
 
@@ -756,3 +758,69 @@ void *memchr(const void *s, int c, size_t n)
 }
 EXPORT_SYMBOL(memchr);
 #endif
+
+static void *check_bytes8(const u8 *start, u8 value, unsigned int bytes)
+{
+	while (bytes) {
+		if (*start != value)
+			return (void *)start;
+		start++;
+		bytes--;
+	}
+	return NULL;
+}
+
+/**
+ * memchr_inv - Find an unmatching character in an area of memory.
+ * @start: The memory area
+ * @c: Find a character other than c
+ * @bytes: The size of the area.
+ *
+ * returns the address of the first character other than @c, or %NULL
+ * if the whole buffer contains just @c.
+ */
+void *memchr_inv(const void *start, int c, size_t bytes)
+{
+	u8 value = c;
+	u64 value64;
+	unsigned int words, prefix;
+
+	if (bytes <= 16)
+		return check_bytes8(start, value, bytes);
+
+	value64 = value;
+#if defined(ARCH_HAS_FAST_MULTIPLIER) && BITS_PER_LONG == 64
+	value64 *= 0x0101010101010101;
+#elif defined(ARCH_HAS_FAST_MULTIPLIER)
+	value64 *= 0x01010101;
+	value64 |= value64 << 32;
+#else
+	value64 |= value64 << 8;
+	value64 |= value64 << 16;
+	value64 |= value64 << 32;
+#endif
+
+	prefix = (unsigned long)start % 8;
+	if (prefix) {
+		u8 *r;
+
+		prefix = 8 - prefix;
+		r = check_bytes8(start, value, prefix);
+		if (r)
+			return r;
+		start += prefix;
+		bytes -= prefix;
+	}
+
+	words = bytes / 8;
+
+	while (words) {
+		if (*(u64 *)start != value64)
+			return check_bytes8(start, value, 8);
+		start += 8;
+		words--;
+	}
+
+	return check_bytes8(start, value, bytes % 8);
+}
+EXPORT_SYMBOL(memchr_inv);