mtd: sm_ftl: Replace deprecated strncpy with sysfs_emit in sm_attr_show

strncpy() is deprecated [1] for NUL-terminated destination buffers
because it does not guarantee NUL termination. It also unnecessarily
NUL-pads the destination buffer if the source is shorter. Replace it
with sysfs_emit() using the "%.*s" format specifier and supply the
length 'sm_attr->len' to improve sm_attr_show().

Return the number of characters actually written to 'buf' instead of
'sm_attr->len'.

Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings
Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

diff --git a/drivers/mtd/sm_ftl.c b/drivers/mtd/sm_ftl.c
index abc7b186353ff8b3fddcaecb3561868b8888bcba..987d481bf26572632508a9628ee2bf67df813f9e 100644 (file)
--- a/drivers/mtd/sm_ftl.c
+++ b/drivers/mtd/sm_ftl.c
@@ -44,8 +44,7 @@ static ssize_t sm_attr_show(struct device *dev, struct device_attribute *attr,
        struct sm_sysfs_attribute *sm_attr =
                container_of(attr, struct sm_sysfs_attribute, dev_attr);
 
-       strncpy(buf, sm_attr->data, sm_attr->len);
-       return sm_attr->len;
+       return sysfs_emit(buf, "%.*s", sm_attr->len, sm_attr->data);
 }