linux-kernel - [PATCH net-next v2 4/5] net: netconsole: Unify Function Return Paths

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20240807091657.4191542-5-leitao@debian.org>
Date: Wed,  7 Aug 2024 02:16:50 -0700
From: Breno Leitao <leitao@...ian.org>
To: kuba@...nel.org,
	davem@...emloft.net,
	edumazet@...gle.com,
	pabeni@...hat.com
Cc: thevlad@...com,
	thepacketgeek@...il.com,
	riel@...riel.com,
	horms@...nel.org,
	netdev@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	paulmck@...nel.org,
	davej@...emonkey.org.uk
Subject: [PATCH net-next v2 4/5] net: netconsole: Unify Function Return Paths

The return flow in netconsole's dynamic functions is currently
inconsistent. This patch aims to streamline and standardize the process
by ensuring that the mutex is unlocked before returning the ret value.

Additionally, this update includes a minor functional change where
certain strnlen() operations are performed with the
dynamic_netconsole_mutex locked. This adjustment is not anticipated to
cause any issues, however, it is crucial to document this change for
clarity.

Signed-off-by: Breno Leitao <leitao@...ian.org>
---
 drivers/net/netconsole.c | 38 +++++++++++++++-----------------------
 1 file changed, 15 insertions(+), 23 deletions(-)

diff --git a/drivers/net/netconsole.c b/drivers/net/netconsole.c
index 0e43b5088bbb..69eeab4a1e26 100644
--- a/drivers/net/netconsole.c
+++ b/drivers/net/netconsole.c
@@ -382,8 +382,7 @@ static ssize_t enabled_store(struct config_item *item,
 		netpoll_cleanup(&nt->np);
 	}
 
-	mutex_unlock(&dynamic_netconsole_mutex);
-	return strnlen(buf, count);
+	ret = strnlen(buf, count);
 out_unlock:
 	mutex_unlock(&dynamic_netconsole_mutex);
 	return ret;
@@ -410,8 +409,7 @@ static ssize_t release_store(struct config_item *item, const char *buf,
 
 	nt->release = release;
 
-	mutex_unlock(&dynamic_netconsole_mutex);
-	return strnlen(buf, count);
+	ret = strnlen(buf, count);
 out_unlock:
 	mutex_unlock(&dynamic_netconsole_mutex);
 	return ret;
@@ -437,9 +435,7 @@ static ssize_t extended_store(struct config_item *item, const char *buf,
 		goto out_unlock;
 
 	nt->extended = extended;
-
-	mutex_unlock(&dynamic_netconsole_mutex);
-	return strnlen(buf, count);
+	ret = strnlen(buf, count);
 out_unlock:
 	mutex_unlock(&dynamic_netconsole_mutex);
 	return ret;
@@ -481,8 +477,7 @@ static ssize_t local_port_store(struct config_item *item, const char *buf,
 	ret = kstrtou16(buf, 10, &nt->np.local_port);
 	if (ret < 0)
 		goto out_unlock;
-	mutex_unlock(&dynamic_netconsole_mutex);
-	return strnlen(buf, count);
+	ret = strnlen(buf, count);
 out_unlock:
 	mutex_unlock(&dynamic_netconsole_mutex);
 	return ret;
@@ -504,8 +499,7 @@ static ssize_t remote_port_store(struct config_item *item,
 	ret = kstrtou16(buf, 10, &nt->np.remote_port);
 	if (ret < 0)
 		goto out_unlock;
-	mutex_unlock(&dynamic_netconsole_mutex);
-	return strnlen(buf, count);
+	ret = strnlen(buf, count);
 out_unlock:
 	mutex_unlock(&dynamic_netconsole_mutex);
 	return ret;
@@ -515,6 +509,7 @@ static ssize_t local_ip_store(struct config_item *item, const char *buf,
 		size_t count)
 {
 	struct netconsole_target *nt = to_target(item);
+	ssize_t ret = -EINVAL;
 
 	mutex_lock(&dynamic_netconsole_mutex);
 	if (nt->enabled) {
@@ -541,17 +536,17 @@ static ssize_t local_ip_store(struct config_item *item, const char *buf,
 			goto out_unlock;
 	}
 
-	mutex_unlock(&dynamic_netconsole_mutex);
-	return strnlen(buf, count);
+	ret = strnlen(buf, count);
 out_unlock:
 	mutex_unlock(&dynamic_netconsole_mutex);
-	return -EINVAL;
+	return ret;
 }
 
 static ssize_t remote_ip_store(struct config_item *item, const char *buf,
 	       size_t count)
 {
 	struct netconsole_target *nt = to_target(item);
+	ssize_t ret = -EINVAL;
 
 	mutex_lock(&dynamic_netconsole_mutex);
 	if (nt->enabled) {
@@ -578,11 +573,10 @@ static ssize_t remote_ip_store(struct config_item *item, const char *buf,
 			goto out_unlock;
 	}
 
-	mutex_unlock(&dynamic_netconsole_mutex);
-	return strnlen(buf, count);
+	ret = strnlen(buf, count);
 out_unlock:
 	mutex_unlock(&dynamic_netconsole_mutex);
-	return -EINVAL;
+	return ret;
 }
 
 static ssize_t remote_mac_store(struct config_item *item, const char *buf,
@@ -590,6 +584,7 @@ static ssize_t remote_mac_store(struct config_item *item, const char *buf,
 {
 	struct netconsole_target *nt = to_target(item);
 	u8 remote_mac[ETH_ALEN];
+	ssize_t ret = -EINVAL;
 
 	mutex_lock(&dynamic_netconsole_mutex);
 	if (nt->enabled) {
@@ -604,11 +599,10 @@ static ssize_t remote_mac_store(struct config_item *item, const char *buf,
 		goto out_unlock;
 	memcpy(nt->np.remote_mac, remote_mac, ETH_ALEN);
 
-	mutex_unlock(&dynamic_netconsole_mutex);
-	return strnlen(buf, count);
+	ret = strnlen(buf, count);
 out_unlock:
 	mutex_unlock(&dynamic_netconsole_mutex);
-	return -EINVAL;
+	return ret;
 }
 
 struct userdatum {
@@ -700,9 +694,7 @@ static ssize_t userdatum_value_store(struct config_item *item, const char *buf,
 	ud = to_userdata(item->ci_parent);
 	nt = userdata_to_target(ud);
 	update_userdata(nt);
-
-	mutex_unlock(&dynamic_netconsole_mutex);
-	return count;
+	ret = count;
 out_unlock:
 	mutex_unlock(&dynamic_netconsole_mutex);
 	return ret;
-- 
2.43.5