From: Borislav Petkov <[email protected]> Date: Sat, 22 Dec 2012 19:02:47 +0100
> Top-posting so that the rest can remain untouched. This bug is fixed in the 'net' tree already by commit: >From 30e6c9fa93cf3dbc7cc6df1d748ad25e4264545a Mon Sep 17 00:00:00 2001 From: Eric Dumazet <[email protected]> Date: Thu, 20 Dec 2012 17:25:08 +0000 Subject: [PATCH 04/10] net: devnet_rename_seq should be a seqcount Using a seqlock for devnet_rename_seq is not a good idea, as device_rename() can sleep. As we hold RTNL, we dont need a protection for writers, and only need a seqcount so that readers can catch a change done by a writer. Bug added in commit c91f6df2db4972d3 (sockopt: Change getsockopt() of SO_BINDTODEVICE to return an interface name) Reported-by: Dave Jones <[email protected]> Signed-off-by: Eric Dumazet <[email protected]> Cc: Brian Haley <[email protected]> Signed-off-by: David S. Miller <[email protected]> --- include/linux/netdevice.h | 2 +- net/core/dev.c | 18 +++++++++--------- net/core/sock.c | 4 ++-- 3 files changed, 12 insertions(+), 12 deletions(-) diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 02e0f6b..c599e47 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -1576,7 +1576,7 @@ extern int call_netdevice_notifiers(unsigned long val, struct net_device *dev); extern rwlock_t dev_base_lock; /* Device list lock */ -extern seqlock_t devnet_rename_seq; /* Device rename lock */ +extern seqcount_t devnet_rename_seq; /* Device rename seq */ #define for_each_netdev(net, d) \ diff --git a/net/core/dev.c b/net/core/dev.c index d0cbc93..515473e 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -203,7 +203,7 @@ static struct list_head offload_base __read_mostly; DEFINE_RWLOCK(dev_base_lock); EXPORT_SYMBOL(dev_base_lock); -DEFINE_SEQLOCK(devnet_rename_seq); +seqcount_t devnet_rename_seq; static inline void dev_base_seq_inc(struct net *net) { @@ -1093,10 +1093,10 @@ int dev_change_name(struct net_device *dev, const char *newname) if (dev->flags & IFF_UP) return -EBUSY; - write_seqlock(&devnet_rename_seq); + write_seqcount_begin(&devnet_rename_seq); if (strncmp(newname, dev->name, IFNAMSIZ) == 0) { - write_sequnlock(&devnet_rename_seq); + write_seqcount_end(&devnet_rename_seq); return 0; } @@ -1104,7 +1104,7 @@ int dev_change_name(struct net_device *dev, const char *newname) err = dev_get_valid_name(net, dev, newname); if (err < 0) { - write_sequnlock(&devnet_rename_seq); + write_seqcount_end(&devnet_rename_seq); return err; } @@ -1112,11 +1112,11 @@ rollback: ret = device_rename(&dev->dev, dev->name); if (ret) { memcpy(dev->name, oldname, IFNAMSIZ); - write_sequnlock(&devnet_rename_seq); + write_seqcount_end(&devnet_rename_seq); return ret; } - write_sequnlock(&devnet_rename_seq); + write_seqcount_end(&devnet_rename_seq); write_lock_bh(&dev_base_lock); hlist_del_rcu(&dev->name_hlist); @@ -1135,7 +1135,7 @@ rollback: /* err >= 0 after dev_alloc_name() or stores the first errno */ if (err >= 0) { err = ret; - write_seqlock(&devnet_rename_seq); + write_seqcount_begin(&devnet_rename_seq); memcpy(dev->name, oldname, IFNAMSIZ); goto rollback; } else { @@ -4180,7 +4180,7 @@ static int dev_ifname(struct net *net, struct ifreq __user *arg) return -EFAULT; retry: - seq = read_seqbegin(&devnet_rename_seq); + seq = read_seqcount_begin(&devnet_rename_seq); rcu_read_lock(); dev = dev_get_by_index_rcu(net, ifr.ifr_ifindex); if (!dev) { @@ -4190,7 +4190,7 @@ retry: strcpy(ifr.ifr_name, dev->name); rcu_read_unlock(); - if (read_seqretry(&devnet_rename_seq, seq)) + if (read_seqcount_retry(&devnet_rename_seq, seq)) goto retry; if (copy_to_user(arg, &ifr, sizeof(struct ifreq))) diff --git a/net/core/sock.c b/net/core/sock.c index a692ef4..bc131d4 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -583,7 +583,7 @@ static int sock_getbindtodevice(struct sock *sk, char __user *optval, goto out; retry: - seq = read_seqbegin(&devnet_rename_seq); + seq = read_seqcount_begin(&devnet_rename_seq); rcu_read_lock(); dev = dev_get_by_index_rcu(net, sk->sk_bound_dev_if); ret = -ENODEV; @@ -594,7 +594,7 @@ retry: strcpy(devname, dev->name); rcu_read_unlock(); - if (read_seqretry(&devnet_rename_seq, seq)) + if (read_seqcount_retry(&devnet_rename_seq, seq)) goto retry; len = strlen(devname) + 1; -- 1.7.11.7 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
