net: dsa: strip sysfs "tagging" string of trailing newline

Currently, dsa_find_tagger_by_name() uses sysfs_streq() which works both
with strings that contain \n at the end (echo ocelot > .../dsa/tagging)
and with strings that don't (printf ocelot > .../dsa/tagging).

There will be a problem once we'll want to construct the modalias string
based on which we auto-load the protocol kernel module. If the sysfs
buffer ends in a newline, we need to strip it first. This is a
preparatory patch specifically for that.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Tested-by: Michael Walle <michael@walle.cc>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Vladimir Oltean 2022-11-15 03:18:45 +02:00 committed by Jakub Kicinski
parent 94793a56b3
commit e8666130b9
3 changed files with 15 additions and 4 deletions

View file

@ -79,7 +79,7 @@ const char *dsa_tag_protocol_to_str(const struct dsa_device_ops *ops)
/* Function takes a reference on the module owning the tagger,
* so dsa_tag_driver_put must be called afterwards.
*/
const struct dsa_device_ops *dsa_find_tagger_by_name(const char *buf)
const struct dsa_device_ops *dsa_find_tagger_by_name(const char *name)
{
const struct dsa_device_ops *ops = ERR_PTR(-ENOPROTOOPT);
struct dsa_tag_driver *dsa_tag_driver;
@ -88,7 +88,7 @@ const struct dsa_device_ops *dsa_find_tagger_by_name(const char *buf)
list_for_each_entry(dsa_tag_driver, &dsa_tag_drivers_list, list) {
const struct dsa_device_ops *tmp = dsa_tag_driver->ops;
if (!sysfs_streq(buf, tmp->name))
if (strcmp(name, tmp->name))
continue;
if (!try_module_get(dsa_tag_driver->owner))

View file

@ -245,7 +245,7 @@ struct dsa_slave_priv {
/* dsa.c */
const struct dsa_device_ops *dsa_tag_driver_get(int tag_protocol);
void dsa_tag_driver_put(const struct dsa_device_ops *ops);
const struct dsa_device_ops *dsa_find_tagger_by_name(const char *buf);
const struct dsa_device_ops *dsa_find_tagger_by_name(const char *name);
bool dsa_db_equal(const struct dsa_db *a, const struct dsa_db *b);

View file

@ -299,12 +299,23 @@ static ssize_t tagging_store(struct device *d, struct device_attribute *attr,
const char *buf, size_t count)
{
const struct dsa_device_ops *new_tag_ops, *old_tag_ops;
const char *end = strchrnul(buf, '\n'), *name;
struct net_device *dev = to_net_dev(d);
struct dsa_port *cpu_dp = dev->dsa_ptr;
size_t len = end - buf;
int err;
/* Empty string passed */
if (!len)
return -ENOPROTOOPT;
name = kstrndup(buf, len, GFP_KERNEL);
if (!name)
return -ENOMEM;
old_tag_ops = cpu_dp->tag_ops;
new_tag_ops = dsa_find_tagger_by_name(buf);
new_tag_ops = dsa_find_tagger_by_name(name);
kfree(name);
/* Bad tagger name, or module is not loaded? */
if (IS_ERR(new_tag_ops))
return PTR_ERR(new_tag_ops);