[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <20240214084829.684541-3-edumazet@google.com>
Date: Wed, 14 Feb 2024 08:48:29 +0000
From: Eric Dumazet <edumazet@...gle.com>
To: Greg Kroah-Hartman <gregkh@...uxfoundation.org>, Christian Brauner <brauner@...nel.org>
Cc: linux-kernel <linux-kernel@...r.kernel.org>, "Rafael J . Wysocki" <rafael@...nel.org>,
Andrew Morton <akpm@...ux-foundation.org>, netdev@...r.kernel.org,
"David S . Miller" <davem@...emloft.net>, Jakub Kicinski <kuba@...nel.org>, Paolo Abeni <pabeni@...hat.com>,
Eric Dumazet <eric.dumazet@...il.com>, Eric Dumazet <edumazet@...gle.com>
Subject: [PATCH 2/2] kobject: reduce uevent_sock_mutex scope
This is a followup of commit a3498436b3a0 ("netns: restrict uevents")
- uevent_sock_mutex no longer protects uevent_seqnum thanks
to prior patch in the series.
- uevent_net_broadcast() can run without holding uevent_sock_mutex.
- Instead of grabbing uevent_sock_mutex before calling
kobject_uevent_net_broadcast(), we can move the
mutex_lock(&uevent_sock_mutex) to the place we iterate over
uevent_sock_list : uevent_net_broadcast_untagged().
After this patch, typical netdevice creations and destructions
calling uevent_net_broadcast_tagged() no longer need to acquire
uevent_sock_mutex.
Signed-off-by: Eric Dumazet <edumazet@...gle.com>
Cc: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Cc: Christian Brauner <brauner@...nel.org>
---
lib/kobject_uevent.c | 9 +++------
1 file changed, 3 insertions(+), 6 deletions(-)
diff --git a/lib/kobject_uevent.c b/lib/kobject_uevent.c
index 9cb1a7fdaeba4fc5c698fbe84f359fb305345be1..03b427e2707e357ab12abeb9da234432c4bc0fb3 100644
--- a/lib/kobject_uevent.c
+++ b/lib/kobject_uevent.c
@@ -42,10 +42,9 @@ struct uevent_sock {
#ifdef CONFIG_NET
static LIST_HEAD(uevent_sock_list);
-#endif
-
/* This lock protects uevent_sock_list */
static DEFINE_MUTEX(uevent_sock_mutex);
+#endif
/* the strings here must match the enum in include/linux/kobject.h */
static const char *kobject_actions[] = {
@@ -315,6 +314,7 @@ static int uevent_net_broadcast_untagged(struct kobj_uevent_env *env,
int retval = 0;
/* send netlink message */
+ mutex_lock(&uevent_sock_mutex);
list_for_each_entry(ue_sk, &uevent_sock_list, list) {
struct sock *uevent_sock = ue_sk->sk;
@@ -334,6 +334,7 @@ static int uevent_net_broadcast_untagged(struct kobj_uevent_env *env,
if (retval == -ENOBUFS || retval == -ESRCH)
retval = 0;
}
+ mutex_unlock(&uevent_sock_mutex);
consume_skb(skb);
return retval;
@@ -589,10 +590,8 @@ int kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
if (retval)
goto exit;
- mutex_lock(&uevent_sock_mutex);
retval = kobject_uevent_net_broadcast(kobj, env, action_string,
devpath);
- mutex_unlock(&uevent_sock_mutex);
#ifdef CONFIG_UEVENT_HELPER
/* call uevent_helper, usually only enabled during early boot */
@@ -743,9 +742,7 @@ static int uevent_net_rcv_skb(struct sk_buff *skb, struct nlmsghdr *nlh,
return -EPERM;
}
- mutex_lock(&uevent_sock_mutex);
ret = uevent_net_broadcast(net->uevent_sock->sk, skb, extack);
- mutex_unlock(&uevent_sock_mutex);
return ret;
}
--
2.43.0.687.g38aa6559b0-goog
Powered by blists - more mailing lists