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	This is an implementation of David Miller's suggested fix in: https://bugzilla.redhat.com/show_bug.cgi?id=470201 It has been updated to use wait_event() instead of wait_event_interruptible(). Paraphrasing the description from the above report, it makes sendmsg() block while UNIX garbage collection is in progress. This avoids a situation where child processes continue to queue new FDs over a AF_UNIX socket to a parent which is in the exit path and running garbage collection on these FDs. This contention can result in soft lockups and oom-killing of unrelated processes. Signed-off-by: dann frazier <dannf@hp.com> Signed-off-by: David S. Miller <davem@davemloft.net>
		
			
				
	
	
		
			71 lines
		
	
	
	
		
			1.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			71 lines
		
	
	
	
		
			1.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
#ifndef __LINUX_NET_AFUNIX_H
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#define __LINUX_NET_AFUNIX_H
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#include <linux/socket.h>
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#include <linux/un.h>
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#include <linux/mutex.h>
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#include <net/sock.h>
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extern void unix_inflight(struct file *fp);
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extern void unix_notinflight(struct file *fp);
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extern void unix_gc(void);
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extern void wait_for_unix_gc(void);
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#define UNIX_HASH_SIZE	256
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extern unsigned int unix_tot_inflight;
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struct unix_address {
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	atomic_t	refcnt;
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	int		len;
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	unsigned	hash;
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	struct sockaddr_un name[0];
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};
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struct unix_skb_parms {
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	struct ucred		creds;		/* Skb credentials	*/
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	struct scm_fp_list	*fp;		/* Passed files		*/
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#ifdef CONFIG_SECURITY_NETWORK
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	u32			secid;		/* Security ID		*/
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#endif
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};
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#define UNIXCB(skb) 	(*(struct unix_skb_parms*)&((skb)->cb))
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#define UNIXCREDS(skb)	(&UNIXCB((skb)).creds)
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#define UNIXSID(skb)	(&UNIXCB((skb)).secid)
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#define unix_state_lock(s)	spin_lock(&unix_sk(s)->lock)
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#define unix_state_unlock(s)	spin_unlock(&unix_sk(s)->lock)
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#define unix_state_lock_nested(s) \
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				spin_lock_nested(&unix_sk(s)->lock, \
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				SINGLE_DEPTH_NESTING)
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#ifdef __KERNEL__
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/* The AF_UNIX socket */
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struct unix_sock {
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	/* WARNING: sk has to be the first member */
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	struct sock		sk;
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        struct unix_address     *addr;
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        struct dentry		*dentry;
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        struct vfsmount		*mnt;
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	struct mutex		readlock;
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        struct sock		*peer;
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        struct sock		*other;
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	struct list_head	link;
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        atomic_long_t           inflight;
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        spinlock_t		lock;
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	unsigned int		gc_candidate : 1;
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	unsigned int		gc_maybe_cycle : 1;
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        wait_queue_head_t       peer_wait;
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};
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#define unix_sk(__sk) ((struct unix_sock *)__sk)
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#ifdef CONFIG_SYSCTL
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extern int unix_sysctl_register(struct net *net);
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extern void unix_sysctl_unregister(struct net *net);
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#else
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static inline int unix_sysctl_register(struct net *net) { return 0; }
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static inline void unix_sysctl_unregister(struct net *net) {}
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#endif
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#endif
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#endif
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