[PATCH v2 net-next 4/6] net: dsa: strip sysfs "tagging" string of trailing newline
From: Vladimir Oltean <vladimir.oltean@nxp.com>
Date: 2022-11-15 01:19:19
Subsystem:
networking [dsa], networking [general], the rest · Maintainers:
Andrew Lunn, Vladimir Oltean, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
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> --- v1->v2: patch is new 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 38c64cc5c0d2..e0ea5b309e61 100644
--- a/net/dsa/dsa.c
+++ b/net/dsa/dsa.c@@ -78,7 +78,7 @@ 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;
@@ -87,7 +87,7 @@ 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 b4b8fe4ed9bf..9fe68d3ae2f5 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 40367ab41cf8..104eab880076 100644
--- a/net/dsa/master.c
+++ b/net/dsa/master.c@@ -300,12 +300,23 @@ 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);
--
2.34.1