diff options
| author |   Eric Dumazet <edumazet@google.com> | 2012-12-20 17:25:08 +0000 |
|---|---|---|
| committer |   David S. Miller <davem@davemloft.net> | 2012-12-21 13:14:01 -0800 |
| commit | 30e6c9fa93cf3dbc7cc6df1d748ad25e4264545a (patch) | |
| tree | e313291a178010fb892d9725cbecb326bd63fdc0 /net/core/dev.c | |
| parent | ip_gre: fix possible use after free (diff) | |
| download | linux-dev-30e6c9fa93cf3dbc7cc6df1d748ad25e4264545a.tar.xz linux-dev-30e6c9fa93cf3dbc7cc6df1d748ad25e4264545a.zip | |
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 <davej@redhat.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Brian Haley <brian.haley@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/core/dev.c')
| -rw-r--r-- | net/core/dev.c | 18 |
1 files changed, 9 insertions, 9 deletions
diff --git a/net/core/dev.c b/net/core/dev.c index d0cbc93fcf32..515473ee52cb 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))) |