mirror of
				https://github.com/torvalds/linux.git
				synced 2025-11-04 10:40:15 +02:00 
			
		
		
		
	mptcp: avoid lock_fast usage in accept path
Once event support is added this may need to allocate memory while msk lock is held with softirqs disabled. Not using lock_fast also allows to do the allocation with GFP_KERNEL. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
		
							parent
							
								
									6c714f1b54
								
							
						
					
					
						commit
						4d54cc3211
					
				
					 3 changed files with 35 additions and 3 deletions
				
			
		| 
						 | 
				
			
			@ -14,6 +14,7 @@
 | 
			
		|||
 */
 | 
			
		||||
struct genl_multicast_group {
 | 
			
		||||
	char			name[GENL_NAMSIZ];
 | 
			
		||||
	u8			flags;
 | 
			
		||||
};
 | 
			
		||||
 | 
			
		||||
struct genl_ops;
 | 
			
		||||
| 
						 | 
				
			
			
 | 
			
		|||
| 
						 | 
				
			
			@ -3260,9 +3260,8 @@ static int mptcp_stream_accept(struct socket *sock, struct socket *newsock,
 | 
			
		|||
		struct mptcp_sock *msk = mptcp_sk(newsock->sk);
 | 
			
		||||
		struct mptcp_subflow_context *subflow;
 | 
			
		||||
		struct sock *newsk = newsock->sk;
 | 
			
		||||
		bool slowpath;
 | 
			
		||||
 | 
			
		||||
		slowpath = lock_sock_fast(newsk);
 | 
			
		||||
		lock_sock(newsk);
 | 
			
		||||
 | 
			
		||||
		/* PM/worker can now acquire the first subflow socket
 | 
			
		||||
		 * lock without racing with listener queue cleanup,
 | 
			
		||||
| 
						 | 
				
			
			@ -3288,7 +3287,7 @@ static int mptcp_stream_accept(struct socket *sock, struct socket *newsock,
 | 
			
		|||
			if (!ssk->sk_socket)
 | 
			
		||||
				mptcp_sock_graft(ssk, newsock);
 | 
			
		||||
		}
 | 
			
		||||
		unlock_sock_fast(newsk, slowpath);
 | 
			
		||||
		release_sock(newsk);
 | 
			
		||||
	}
 | 
			
		||||
 | 
			
		||||
	if (inet_csk_listen_poll(ssock->sk))
 | 
			
		||||
| 
						 | 
				
			
			
 | 
			
		|||
| 
						 | 
				
			
			@ -1360,11 +1360,43 @@ static struct genl_family genl_ctrl __ro_after_init = {
 | 
			
		|||
	.netnsok = true,
 | 
			
		||||
};
 | 
			
		||||
 | 
			
		||||
static int genl_bind(struct net *net, int group)
 | 
			
		||||
{
 | 
			
		||||
	const struct genl_family *family;
 | 
			
		||||
	unsigned int id;
 | 
			
		||||
	int ret = 0;
 | 
			
		||||
 | 
			
		||||
	genl_lock_all();
 | 
			
		||||
 | 
			
		||||
	idr_for_each_entry(&genl_fam_idr, family, id) {
 | 
			
		||||
		const struct genl_multicast_group *grp;
 | 
			
		||||
		int i;
 | 
			
		||||
 | 
			
		||||
		if (family->n_mcgrps == 0)
 | 
			
		||||
			continue;
 | 
			
		||||
 | 
			
		||||
		i = group - family->mcgrp_offset;
 | 
			
		||||
		if (i < 0 || i >= family->n_mcgrps)
 | 
			
		||||
			continue;
 | 
			
		||||
 | 
			
		||||
		grp = &family->mcgrps[i];
 | 
			
		||||
		if ((grp->flags & GENL_UNS_ADMIN_PERM) &&
 | 
			
		||||
		    !ns_capable(net->user_ns, CAP_NET_ADMIN))
 | 
			
		||||
			ret = -EPERM;
 | 
			
		||||
 | 
			
		||||
		break;
 | 
			
		||||
	}
 | 
			
		||||
 | 
			
		||||
	genl_unlock_all();
 | 
			
		||||
	return ret;
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
static int __net_init genl_pernet_init(struct net *net)
 | 
			
		||||
{
 | 
			
		||||
	struct netlink_kernel_cfg cfg = {
 | 
			
		||||
		.input		= genl_rcv,
 | 
			
		||||
		.flags		= NL_CFG_F_NONROOT_RECV,
 | 
			
		||||
		.bind		= genl_bind,
 | 
			
		||||
	};
 | 
			
		||||
 | 
			
		||||
	/* we'll bump the group number right afterwards */
 | 
			
		||||
| 
						 | 
				
			
			
 | 
			
		|||
		Loading…
	
		Reference in a new issue