net: af_unix should disable preempt around sock_prot_inuse_add()
Subsystems (3)
PATCH 1/1 net: af_unix should disable preempt around sock_prot_inuse_add()
BUG: using smp_processor_id() in preemptible [00000000] code: ini
caller is sock_prot_inuse_add+0x24/0x42
Pid: 738, comm: init-early.sh Tainted: G W 2.6.28-rc6-nex
Call Trace: [<ffffffff8037fb72>] debug_smp_processor_id+0xca/0xe0 [<ffffffff8046afc9>] sock_prot_inuse_add+0x24/0x42 [<ffffffff804baf2c>] unix_create1+0x161/0x176 [<ffffffff804bb03d>] unix_stream_connect+0x94/0x3b0 [<ffffffff80468a84>] sys_connect+0x68/0x8e [<ffffffff8020b75b>] system_call_fastpath+0x16/0x1b
---
net/unix/af_unix.c | 8 ++++++-- 1 files changed, 6 insertions(+), 2 deletions(-)
net/unix/af_unix.c +6 -2
@@ -361,7 +361,9 @@ static void unix_sock_destructor(struct sock *sk)unix_release_addr (u->addr);atomic_dec (&unix_nr_socks); +preempt_disable ();sock_prot_inuse_add (sock_net (sk), sk->sk_prot,-1 ); +preempt_enable ();#ifdef UNIX_REFCNT_DEBUG printk (KERN_DEBUG "UNIX %p is destroyed, %d are still alive.\n" , sk,atomic_read (&unix_nr_socks));
@@ -612,9 +614,11 @@ static struct sock *unix_create1(struct net *net, struct socket *sock) out:if (sk ==NULL )atomic_dec (&unix_nr_socks); -else +else { +preempt_disable ();sock_prot_inuse_add (sock_net (sk), sk->sk_prot,1 ); - +preempt_enable (); + }return sk; }
Quoted 40 lines · Alexander Beregalov
BUG: using smp_processor_id() in preemptible [00000000] code: inicaller is
sock_prot_inuse_add+0x24/0x42
Pid: 738, comm:init-early.shTainted: G W 2.6.28-rc6-nexCall Trace: [<ffffffff8037fb72>] debug_smp_processor_id+0xca/0xe0 [<ffffffff8046afc9>] sock_prot_inuse_add+0x24/0x42 [<ffffffff804baf2c>] unix_create1+0x161/0x176 [<ffffffff804bb03d>] unix_stream_connect+0x94/0x3b0 [<ffffffff80468a84>] sys_connect+0x68/0x8e [<ffffffff8020b75b>] system_call_fastpath+0x16/0x1bSigned-off-by Alexander Beregalov <[email protected]>---
net/unix/af_unix.c | 8 ++++++-- 1 files changed, 6 insertions(+), 2 deletions(-)net/unix/af_unix.c +2
-0@@ -361,7 +361,9 @@ static void unix_sock_destructor(struct sock *sk)unix_release_addr (u->addr);atomic_dec (&unix_nr_socks); +preempt_disable ();sock_prot_inuse_add (sock_net (sk), sk->sk_prot,-1 ); +preempt_enable ();#ifdef UNIX_REFCNT_DEBUG printk (KERN_DEBUG "UNIX %p is destroyed, %d are still alive.\n" , sk,atomic_read (&unix_nr_socks));@@ -612,9 +614,11 @@ static struct sock *unix_create1(struct net *net, struct socket *sock) out:if (sk ==NULL )atomic_dec (&unix_nr_socks);
net/unix/af_unix.c static struct sock *unix_create1(struct net *net, struct socket *sock) · line 624
Quoted 10 lines
net/unix/af_unix.c +4
-2-else +else { +preempt_disable ();sock_prot_inuse_add (sock_net (sk), sk->sk_prot,1 ); - +preempt_enable (); + }return sk; }
Thanks Alexander, but this problem (and others) was fixed few hours ago by two commits on net-next-2.6
commit 6f756a8c36bf54d0afb1d457082b3e3033d951a7
net: Make sure BHs are disabled in sock_prot_inuse_add()
The rule of calling sock_prot_inuse_add() is that BHs must be disabled. Some new calls were added where this was not true and this tiggers warnings as reported by Ilpo.
Fix this by adding explicit BH disabling around those call sites.
commit 920de804bca61f88643bc9171bcd06f1a56c6258
net: Make sure BHs are disabled in sock_prot_inuse_add()
The rule of calling sock_prot_inuse_add() is that BHs must be disabled. Some new calls were added where this was not true and this tiggers warnings as reported by Ilpo.
Fix this by adding explicit BH disabling around those call sites, or moving sock_prot_inuse_add() call inside an existing BH disabled section.