From 1e66df3ee301209f4a38df097d7cc5cb9b367a3f Mon Sep 17 00:00:00 2001 From: Jeremy Fitzhardinge Date: Tue, 17 Jul 2007 18:37:02 -0700 Subject: [PATCH] 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 Signed-off-by: Chris Wright Cc: Andrew Morton Cc: Randy Dunlap Cc: YOSHIFUJI Hideaki Cc: Akinobu Mita Cc: Arnaldo Carvalho de Melo Cc: Al Viro Cc: Panagiotis Issaris Cc: Rene Scharfe --- include/linux/string.h | 1 + mm/util.c | 26 +++++++++++++++++++++++-- net/irda/irias_object.c | 43 +++++------------------------------------ 3 files changed, 30 insertions(+), 40 deletions(-) diff --git a/include/linux/string.h b/include/linux/string.h index 7f2eb6a477..ee5e9ccc4a 100644 --- a/include/linux/string.h +++ b/include/linux/string.h @@ -105,6 +105,7 @@ extern void * memchr(const void *,int,__kernel_size_t); #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 78f3783bdc..bf340d8068 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 */ @@ -26,6 +25,30 @@ char *kstrdup(const char *s, gfp_t gfp) } 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 * @@ -80,7 +103,6 @@ EXPORT_SYMBOL(krealloc); /* * 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 4adaae242b..cf30245709 100644 --- a/net/irda/irias_object.c +++ b/net/irda/irias_object.c @@ -36,39 +36,6 @@ hashbin_t *irias_objects; */ 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 @@ struct ias_object *irias_new_object( char *name, int id) } 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 @@ void irias_add_integer_attrib(struct ias_object *obj, char *name, int value, } 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 @@ void irias_add_octseq_attrib(struct ias_object *obj, char *name, __u8 *octets, } 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 @@ void irias_add_string_attrib(struct ias_object *obj, char *name, char *value, } 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 @@ struct ias_value *irias_new_string_value(char *string) 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); -- 2.39.5