kstrimdup creates a whitespace-trimmed duplicate of the passed in null-terminated string. This is useful for strings coming from sysfs that often include trailing whitespace due to user input.
Thanks to Joe Perches for this implementation.
Signed-off-by: Sebastian Capella sebastian.capella@linaro.org Cc: Andrew Morton akpm@linux-foundation.org Cc: Joe Perches joe@perches.com Cc: Mikulas Patocka mpatocka@redhat.com Cc: David Rientjes rientjes@google.com Cc: Rik van Riel riel@redhat.com (commit_signer:5/10=50%) Cc: Michel Lespinasse walken@google.com Cc: Shaohua Li shli@kernel.org Cc: Jerome Marchand jmarchan@redhat.com Cc: Mikulas Patocka mpatocka@redhat.com Cc: Joonsoo Kim iamjoonsoo.kim@lge.com --- include/linux/string.h | 1 + mm/util.c | 30 ++++++++++++++++++++++++++++++ 2 files changed, 31 insertions(+)
diff --git a/include/linux/string.h b/include/linux/string.h index ac889c5..f29f9a0 100644 --- a/include/linux/string.h +++ b/include/linux/string.h @@ -114,6 +114,7 @@ void *memchr_inv(const void *s, int c, size_t n);
extern char *kstrdup(const char *s, gfp_t gfp); extern char *kstrndup(const char *s, size_t len, gfp_t gfp); +extern char *kstrimdup(const char *s, gfp_t gfp); extern void *kmemdup(const void *src, size_t len, gfp_t gfp);
extern char **argv_split(gfp_t gfp, const char *str, int *argcp); diff --git a/mm/util.c b/mm/util.c index 808f375..a8b731c 100644 --- a/mm/util.c +++ b/mm/util.c @@ -1,6 +1,7 @@ #include <linux/mm.h> #include <linux/slab.h> #include <linux/string.h> +#include <linux/ctype.h> #include <linux/export.h> #include <linux/err.h> #include <linux/sched.h> @@ -63,6 +64,35 @@ char *kstrndup(const char *s, size_t max, gfp_t gfp) EXPORT_SYMBOL(kstrndup);
/** + * kstrimdup - Trim and copy a %NUL terminated string. + * @s: the string to trim and duplicate + * @gfp: the GFP mask used in the kmalloc() call when allocating memory + * + * Returns an address, which the caller must kfree, containing + * a duplicate of the passed string with leading and/or trailing + * whitespace (as defined by isspace) removed. + */ +char *kstrimdup(const char *s, gfp_t gfp) +{ + char *buf; + char *begin = skip_spaces(s); + size_t len = strlen(begin); + + while (len && isspace(begin[len - 1])) + len--; + + buf = kmalloc_track_caller(len + 1, gfp); + if (!buf) + return NULL; + + memcpy(buf, begin, len); + buf[len] = '\0'; + + return buf; +} +EXPORT_SYMBOL(kstrimdup); + +/** * kmemdup - duplicate region of memory * * @src: memory region to duplicate