[PATCH v3 05/28] switch netlink_getsockbyfilp() to taking descriptor
From: Al Viro <viro@zeniv.linux.org.uk>
Date: 2024-11-02 05:08:29
Also in:
cgroups, kvm, linux-fsdevel
Subsystem:
networking [general], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
the only call site (in do_mq_notify()) obtains the argument from an immediately preceding fdget() and it is immediately followed by fdput(); might as well just replace it with a variant that would take a descriptor instead of struct file * and have file lookups handled inside that function. Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> --- include/linux/netlink.h | 2 +- ipc/mqueue.c | 8 +------- net/netlink/af_netlink.c | 9 +++++++-- 3 files changed, 9 insertions(+), 10 deletions(-)
diff --git a/include/linux/netlink.h b/include/linux/netlink.h
index b332c2048c75..a48a30842d84 100644
--- a/include/linux/netlink.h
+++ b/include/linux/netlink.h@@ -239,7 +239,7 @@ int netlink_register_notifier(struct notifier_block *nb); int netlink_unregister_notifier(struct notifier_block *nb); /* finegrained unicast helpers: */ -struct sock *netlink_getsockbyfilp(struct file *filp); +struct sock *netlink_getsockbyfd(int fd); int netlink_attachskb(struct sock *sk, struct sk_buff *skb, long *timeo, struct sock *ssk); void netlink_detachskb(struct sock *sk, struct sk_buff *skb);
diff --git a/ipc/mqueue.c b/ipc/mqueue.c
index 34fa0bd8bb11..fd05e3d4f7b6 100644
--- a/ipc/mqueue.c
+++ b/ipc/mqueue.c@@ -1355,13 +1355,7 @@ static int do_mq_notify(mqd_t mqdes, const struct sigevent *notification) skb_put(nc, NOTIFY_COOKIE_LEN); /* and attach it to the socket */ retry: - f = fdget(notification->sigev_signo); - if (!fd_file(f)) { - ret = -EBADF; - goto out; - } - sock = netlink_getsockbyfilp(fd_file(f)); - fdput(f); + sock = netlink_getsockbyfd(notification->sigev_signo); if (IS_ERR(sock)) { ret = PTR_ERR(sock); goto free_skb;
diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index 0b7a89db3ab7..42451ac355d0 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c@@ -1180,11 +1180,16 @@ static struct sock *netlink_getsockbyportid(struct sock *ssk, u32 portid) return sock; } -struct sock *netlink_getsockbyfilp(struct file *filp) +struct sock *netlink_getsockbyfd(int fd) { - struct inode *inode = file_inode(filp); + CLASS(fd, f)(fd); + struct inode *inode; struct sock *sock; + if (fd_empty(f)) + return ERR_PTR(-EBADF); + + inode = file_inode(fd_file(f)); if (!S_ISSOCK(inode->i_mode)) return ERR_PTR(-ENOTSOCK);
--
2.39.5