From e8666130b995a6a1a99c319d33fae2046213c39b Mon Sep 17 00:00:00 2001 From: Vladimir Oltean Date: Tue, 15 Nov 2022 03:18:45 +0200 Subject: [PATCH] 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 Tested-by: Michael Walle Signed-off-by: Jakub Kicinski --- net/dsa/dsa.c | 4 ++-- net/dsa/dsa_priv.h | 2 +- net/dsa/master.c | 13 ++++++++++++- 3 files changed, 15 insertions(+), 4 deletions(-) diff --git a/net/dsa/dsa.c b/net/dsa/dsa.c index cc6a497..f74ddda 100644 --- a/net/dsa/dsa.c +++ b/net/dsa/dsa.c @@ -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)) diff --git a/net/dsa/dsa_priv.h b/net/dsa/dsa_priv.h index 020386f..4559c0e 100644 --- a/net/dsa/dsa_priv.h +++ b/net/dsa/dsa_priv.h @@ -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); diff --git a/net/dsa/master.c b/net/dsa/master.c index 421de16..f443bf4 100644 --- a/net/dsa/master.c +++ b/net/dsa/master.c @@ -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); -- 2.7.4