[PATCH 3.16 17/99] lib/string.c: remove duplicated function

From: Ben Hutchings
Date: Tue Apr 02 2019 - 09:45:48 EST

3.16.65-rc1 review patch. If anyone has any objections, please let me know.


From: Rasmus Villemoes <linux@xxxxxxxxxxxxxxxxxx>

commit cd514e727b18ff4d189b8e268db13729a4175091 upstream.

lib/string.c contains two functions, strnicmp and strncasecmp, which do
roughly the same thing, namely compare two strings case-insensitively up
to a given bound. They have slightly different implementations, but the
only important difference is that strncasecmp doesn't handle len==0
appropriately; it effectively becomes strcasecmp in that case. strnicmp
correctly says that two strings are always equal in their first 0

strncasecmp is the POSIX name for this functionality. So rename the
non-broken function to the standard name. To minimize the impact on the
rest of the kernel (and since both are exported to modules), make strnicmp
a wrapper for strncasecmp.

Signed-off-by: Rasmus Villemoes <linux@xxxxxxxxxxxxxxxxxx>
Cc: Grant Likely <grant.likely@xxxxxxxxxx>
Cc: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Cc: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Cc: "H. Peter Anvin" <hpa@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
lib/string.c | 27 ++++++++++-----------------
1 file changed, 10 insertions(+), 17 deletions(-)

--- a/lib/string.c
+++ b/lib/string.c
@@ -31,14 +31,14 @@
#include <asm/word-at-a-time.h>
#include <asm/page.h>

- * strnicmp - Case insensitive, length-limited string comparison
+ * strncasecmp - Case insensitive, length-limited string comparison
* @s1: One string
* @s2: The other string
* @len: the maximum number of characters to compare
-int strnicmp(const char *s1, const char *s2, size_t len)
+int strncasecmp(const char *s1, const char *s2, size_t len)
/* Yes, Virginia, it had better be unsigned */
unsigned char c1, c2;
@@ -60,6 +60,13 @@ int strnicmp(const char *s1, const char
} while (--len);
return (int)c1 - (int)c2;
+int strnicmp(const char *s1, const char *s2, size_t len)
+ return strncasecmp(s1, s2, len);

@@ -77,20 +84,6 @@ int strcasecmp(const char *s1, const cha

-int strncasecmp(const char *s1, const char *s2, size_t n)
- int c1, c2;
- do {
- c1 = tolower(*s1++);
- c2 = tolower(*s2++);
- } while ((--n > 0) && c1 == c2 && c1 != 0);
- return c1 - c2;
* strcpy - Copy a %NUL terminated string