add kstrndup
Add a kstrndup function, modelled on strndup. Like strndup this
returns a string copied into its own allocated memory, but it copies
no more than the specified number of bytes from the source.
Remove private strndup() from irda code.
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Cc: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Cc: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Arnaldo Carvalho de Melo <acme@mandriva.com>
Cc: Al Viro <viro@ftp.linux.org.uk>
Cc: Panagiotis Issaris <takis@issaris.org>
Cc: Rene Scharfe <rene.scharfe@lsrfire.ath.cx>
diff --git a/include/linux/string.h b/include/linux/string.h
index 7f2eb6a..ee5e9cc 100644
--- a/include/linux/string.h
+++ b/include/linux/string.h
@@ -105,6 +105,7 @@
#endif
extern char *kstrdup(const char *s, gfp_t gfp);
+extern char *kstrndup(const char *s, size_t len, gfp_t gfp);
extern void *kmemdup(const void *src, size_t len, gfp_t gfp);
#ifdef __cplusplus
diff --git a/mm/util.c b/mm/util.c
index 78f3783..bf340d8 100644
--- a/mm/util.c
+++ b/mm/util.c
@@ -6,7 +6,6 @@
/**
* kstrdup - allocate space for and copy an existing string
- *
* @s: the string to duplicate
* @gfp: the GFP mask used in the kmalloc() call when allocating memory
*/
@@ -27,6 +26,30 @@
EXPORT_SYMBOL(kstrdup);
/**
+ * kstrndup - allocate space for and copy an existing string
+ * @s: the string to duplicate
+ * @max: read at most @max chars from @s
+ * @gfp: the GFP mask used in the kmalloc() call when allocating memory
+ */
+char *kstrndup(const char *s, size_t max, gfp_t gfp)
+{
+ size_t len;
+ char *buf;
+
+ if (!s)
+ return NULL;
+
+ len = strnlen(s, max);
+ buf = kmalloc_track_caller(len+1, gfp);
+ if (buf) {
+ memcpy(buf, s, len);
+ buf[len] = '\0';
+ }
+ return buf;
+}
+EXPORT_SYMBOL(kstrndup);
+
+/**
* kmemdup - duplicate region of memory
*
* @src: memory region to duplicate
@@ -80,7 +103,6 @@
/*
* strndup_user - duplicate an existing string from user space
- *
* @s: The string to duplicate
* @n: Maximum number of bytes to copy, including the trailing NUL.
*/
diff --git a/net/irda/irias_object.c b/net/irda/irias_object.c
index 4adaae2..cf30245 100644
--- a/net/irda/irias_object.c
+++ b/net/irda/irias_object.c
@@ -36,39 +36,6 @@
*/
struct ias_value irias_missing = { IAS_MISSING, 0, 0, 0, {0}};
-/*
- * Function strndup (str, max)
- *
- * My own kernel version of strndup!
- *
- * Faster, check boundary... Jean II
- */
-static char *strndup(char *str, size_t max)
-{
- char *new_str;
- int len;
-
- /* Check string */
- if (str == NULL)
- return NULL;
- /* Check length, truncate */
- len = strlen(str);
- if(len > max)
- len = max;
-
- /* Allocate new string */
- new_str = kmalloc(len + 1, GFP_ATOMIC);
- if (new_str == NULL) {
- IRDA_WARNING("%s: Unable to kmalloc!\n", __FUNCTION__);
- return NULL;
- }
-
- /* Copy and truncate */
- memcpy(new_str, str, len);
- new_str[len] = '\0';
-
- return new_str;
-}
/*
* Function ias_new_object (name, id)
@@ -90,7 +57,7 @@
}
obj->magic = IAS_OBJECT_MAGIC;
- obj->name = strndup(name, IAS_MAX_CLASSNAME);
+ obj->name = kstrndup(name, IAS_MAX_CLASSNAME, GFP_ATOMIC);
if (!obj->name) {
IRDA_WARNING("%s(), Unable to allocate name!\n",
__FUNCTION__);
@@ -360,7 +327,7 @@
}
attrib->magic = IAS_ATTRIB_MAGIC;
- attrib->name = strndup(name, IAS_MAX_ATTRIBNAME);
+ attrib->name = kstrndup(name, IAS_MAX_ATTRIBNAME, GFP_ATOMIC);
/* Insert value */
attrib->value = irias_new_integer_value(value);
@@ -404,7 +371,7 @@
}
attrib->magic = IAS_ATTRIB_MAGIC;
- attrib->name = strndup(name, IAS_MAX_ATTRIBNAME);
+ attrib->name = kstrndup(name, IAS_MAX_ATTRIBNAME, GFP_ATOMIC);
attrib->value = irias_new_octseq_value( octets, len);
if (!attrib->name || !attrib->value) {
@@ -446,7 +413,7 @@
}
attrib->magic = IAS_ATTRIB_MAGIC;
- attrib->name = strndup(name, IAS_MAX_ATTRIBNAME);
+ attrib->name = kstrndup(name, IAS_MAX_ATTRIBNAME, GFP_ATOMIC);
attrib->value = irias_new_string_value(value);
if (!attrib->name || !attrib->value) {
@@ -506,7 +473,7 @@
value->type = IAS_STRING;
value->charset = CS_ASCII;
- value->t.string = strndup(string, IAS_MAX_STRING);
+ value->t.string = kstrndup(string, IAS_MAX_STRING, GFP_ATOMIC);
if (!value->t.string) {
IRDA_WARNING("%s: Unable to kmalloc!\n", __FUNCTION__);
kfree(value);