kstrdup_trimnl creates a duplicate of the passed in null-terminated string. If a trailing newline is found, it is removed before duplicating. This is useful for strings coming from sysfs that often include trailing whitespace due to user input.
Signed-off-by: Sebastian Capella <[email protected]> Cc: Andrew Morton <[email protected]> Cc: Rik van Riel <[email protected]> (commit_signer:5/10=50%) Cc: Michel Lespinasse <[email protected]> Cc: Shaohua Li <[email protected]> Cc: Jerome Marchand <[email protected]> Cc: Mikulas Patocka <[email protected]> Cc: Joonsoo Kim <[email protected]> Cc: Joe Perches <[email protected]> Cc: David Rientjes <[email protected]> Cc: Alexey Dobriyan <[email protected]> --- include/linux/string.h | 1 + mm/util.c | 29 +++++++++++++++++++++++++++++ 2 files changed, 30 insertions(+) diff --git a/include/linux/string.h b/include/linux/string.h index ac889c5..e7ec8c0 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 *kstrdup_trimnl(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..0bab867 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 +64,34 @@ char *kstrndup(const char *s, size_t max, gfp_t gfp) EXPORT_SYMBOL(kstrndup); /** + * kstrdup_trimnl - Copy a %NUL terminated string, removing one trailing + * newline if present. + * @s: the string to 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 a single trailing newline + * removed if present. + */ +char *kstrdup_trimnl(const char *s, gfp_t gfp) +{ + char *buf; + size_t len = strlen(s); + if (len >= 1 && s[len - 1] == '\n') + len--; + + buf = kmalloc_track_caller(len + 1, gfp); + if (!buf) + return NULL; + + memcpy(buf, s, len); + buf[len] = '\0'; + + return buf; +} +EXPORT_SYMBOL(kstrdup_trimnl); + +/** * kmemdup - duplicate region of memory * * @src: memory region to duplicate -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
