korg/linux
0
0
Fork 0
mirror of https://mirrors.bfsu.edu.cn/git/linux.git synced 2024-09-21 20:22:13 +08:00
Code Issues Packages Projects Releases Wiki Activity

net: sk_{detach|attach}_filter() rcu fixes

Browse Source 
sk_attach_filter() and sk_detach_filter() are run with socket locked.

Use the appropriate rcu_dereference_protected() instead of blocking BH,
and rcu_dereference_bh().
There is no point adding BH prevention and memory barrier.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric Dumazet 2010-09-27 06:07:30 +00:00 committed by David S. Miller
parent 7fa7cb7109
commit f91ff5b9ff
1 changed files with 4 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

10
net/core/filter.c
View File

@ -638,10 +638,9 @@ int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk)
return err; return err;
} }
rcu_read_lock_bh(); old_fp = rcu_dereference_protected(sk->sk_filter,
old_fp = rcu_dereference_bh(sk->sk_filter); sock_owned_by_user(sk));
rcu_assign_pointer(sk->sk_filter, fp); rcu_assign_pointer(sk->sk_filter, fp);
rcu_read_unlock_bh();
if (old_fp) if (old_fp)
sk_filter_delayed_uncharge(sk, old_fp); sk_filter_delayed_uncharge(sk, old_fp);
@ -654,14 +653,13 @@ int sk_detach_filter(struct sock *sk)
int ret = -ENOENT; int ret = -ENOENT;
struct sk_filter *filter; struct sk_filter *filter;
rcu_read_lock_bh(); filter = rcu_dereference_protected(sk->sk_filter,
filter = rcu_dereference_bh(sk->sk_filter); sock_owned_by_user(sk));
if (filter) { if (filter) {
rcu_assign_pointer(sk->sk_filter, NULL); rcu_assign_pointer(sk->sk_filter, NULL);
sk_filter_delayed_uncharge(sk, filter); sk_filter_delayed_uncharge(sk, filter);
ret = 0; ret = 0;
} }
rcu_read_unlock_bh();
return ret; return ret;
} }
EXPORT_SYMBOL_GPL(sk_detach_filter); EXPORT_SYMBOL_GPL(sk_detach_filter);