I'm not sure why, but the hlist for each entry iterators were conceived
list_for_each_entry(pos, head, member)
The hlist ones were greedy and wanted an extra parameter:
hlist_for_each_entry(tpos, pos, head, member)
Why did they need an extra pos parameter? I'm not quite sure. Not only
they don't really need it, it also prevents the iterator from looking
exactly like the list iterator, which is unfortunate.
Besides the semantic patch, there was some manual work required:
- Fix up the actual hlist iterators in linux/list.h
- Fix up the declaration of other iterators based on the hlist ones.
- A very small amount of places were using the 'node' parameter, this
was modified to use 'obj->member' instead.
- Coccinelle didn't handle the hlist_for_each_entry_safe iterator
properly, so those had to be fixed up manually.
The semantic patch which is mostly the work of Peter Senna Tschudin is here:
@@
iterator name hlist_for_each_entry, hlist_for_each_entry_continue, hlist_for_each_entry_from, hlist_for_each_entry_rcu, hlist_for_each_entry_rcu_bh, hlist_for_each_entry_continue_rcu_bh, for_each_busy_worker, ax25_uid_for_each, ax25_for_each, inet_bind_bucket_for_each, sctp_for_each_hentry, sk_for_each, sk_for_each_rcu, sk_for_each_from, sk_for_each_safe, sk_for_each_bound, hlist_for_each_entry_safe, hlist_for_each_entry_continue_rcu, nr_neigh_for_each, nr_neigh_for_each_safe, nr_node_for_each, nr_node_for_each_safe, for_each_gfn_indirect_valid_sp, for_each_gfn_sp, for_each_host;
type T;
expression a,c,d,e;
identifier b;
statement S;
@@
-T b;
<+... when != b
(
hlist_for_each_entry(a,
- b,
c, d) S
|
hlist_for_each_entry_continue(a,
- b,
c) S
|
hlist_for_each_entry_from(a,
- b,
c) S
|
hlist_for_each_entry_rcu(a,
- b,
c, d) S
|
hlist_for_each_entry_rcu_bh(a,
- b,
c, d) S
|
hlist_for_each_entry_continue_rcu_bh(a,
- b,
c) S
|
for_each_busy_worker(a, c,
- b,
d) S
|
ax25_uid_for_each(a,
- b,
c) S
|
ax25_for_each(a,
- b,
c) S
|
inet_bind_bucket_for_each(a,
- b,
c) S
|
sctp_for_each_hentry(a,
- b,
c) S
|
sk_for_each(a,
- b,
c) S
|
sk_for_each_rcu(a,
- b,
c) S
|
sk_for_each_from
-(a, b)
+(a)
S
+ sk_for_each_from(a) S
|
sk_for_each_safe(a,
- b,
c, d) S
|
sk_for_each_bound(a,
- b,
c) S
|
hlist_for_each_entry_safe(a,
- b,
c, d, e) S
|
hlist_for_each_entry_continue_rcu(a,
- b,
c) S
|
nr_neigh_for_each(a,
- b,
c) S
|
nr_neigh_for_each_safe(a,
- b,
c, d) S
|
nr_node_for_each(a,
- b,
c) S
|
nr_node_for_each_safe(a,
- b,
c, d) S
|
- for_each_gfn_sp(a, c, d, b) S
+ for_each_gfn_sp(a, c, d) S
|
- for_each_gfn_indirect_valid_sp(a, c, d, b) S
+ for_each_gfn_indirect_valid_sp(a, c, d) S
|
for_each_host(a,
- b,
c) S
|
for_each_host_safe(a,
- b,
c, d) S
|
for_each_mesh_entry(a,
- b,
c, d) S
)
...+>
[akpm@linux-foundation.org: drop bogus change from net/ipv4/raw.c]
[akpm@linux-foundation.org: drop bogus hunk from net/ipv6/raw.c]
[akpm@linux-foundation.org: checkpatch fixes]
[akpm@linux-foundation.org: fix warnings]
[akpm@linux-foudnation.org: redo intrusive kvm changes]
Tested-by: Peter Senna Tschudin <peter.senna@gmail.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch reduces the critical section protected by sco_conn_lock in
sco_conn_ready function. The lock is acquired only when it is really
needed.
This patch fixes the following lockdep warning which is generated
when the host terminates a SCO connection.
Today, this warning is a false positive. There is no way those
two threads reported by lockdep are running at the same time since
hdev->workqueue (where rx_work is queued) is single-thread. However,
if somehow this behavior is changed in future, we will have a
potential deadlock.
======================================================
[ INFO: possible circular locking dependency detected ]
3.8.0-rc1+ #7 Not tainted
-------------------------------------------------------
kworker/u:1H/1018 is trying to acquire lock:
(&(&conn->lock)->rlock){+.+...}, at: [<ffffffffa0033ba6>] sco_chan_del+0x66/0x190 [bluetooth]
but task is already holding lock:
(slock-AF_BLUETOOTH-BTPROTO_SCO){+.+...}, at: [<ffffffffa0033d5a>] sco_conn_del+0x8a/0xe0 [bluetooth]
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (slock-AF_BLUETOOTH-BTPROTO_SCO){+.+...}:
[<ffffffff81083011>] lock_acquire+0xb1/0xe0
[<ffffffff813efd01>] _raw_spin_lock+0x41/0x80
[<ffffffffa003436e>] sco_connect_cfm+0xbe/0x350 [bluetooth]
[<ffffffffa0015d6c>] hci_event_packet+0xd3c/0x29b0 [bluetooth]
[<ffffffffa0004583>] hci_rx_work+0x133/0x870 [bluetooth]
[<ffffffff8104d65f>] process_one_work+0x2bf/0x4f0
[<ffffffff81050022>] worker_thread+0x2b2/0x3e0
[<ffffffff81056021>] kthread+0xd1/0xe0
[<ffffffff813f14bc>] ret_from_fork+0x7c/0xb0
-> #0 (&(&conn->lock)->rlock){+.+...}:
[<ffffffff81082215>] __lock_acquire+0x1465/0x1c70
[<ffffffff81083011>] lock_acquire+0xb1/0xe0
[<ffffffff813efd01>] _raw_spin_lock+0x41/0x80
[<ffffffffa0033ba6>] sco_chan_del+0x66/0x190 [bluetooth]
[<ffffffffa0033d6d>] sco_conn_del+0x9d/0xe0 [bluetooth]
[<ffffffffa0034653>] sco_disconn_cfm+0x53/0x60 [bluetooth]
[<ffffffffa000fef3>] hci_disconn_complete_evt.isra.54+0x363/0x3c0 [bluetooth]
[<ffffffffa00150f7>] hci_event_packet+0xc7/0x29b0 [bluetooth]
[<ffffffffa0004583>] hci_rx_work+0x133/0x870 [bluetooth]
[<ffffffff8104d65f>] process_one_work+0x2bf/0x4f0
[<ffffffff81050022>] worker_thread+0x2b2/0x3e0
[<ffffffff81056021>] kthread+0xd1/0xe0
[<ffffffff813f14bc>] ret_from_fork+0x7c/0xb0
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(slock-AF_BLUETOOTH-BTPROTO_SCO);
lock(&(&conn->lock)->rlock);
lock(slock-AF_BLUETOOTH-BTPROTO_SCO);
lock(&(&conn->lock)->rlock);
*** DEADLOCK ***
4 locks held by kworker/u:1H/1018:
#0: (hdev->name#2){.+.+.+}, at: [<ffffffff8104d5f8>] process_one_work+0x258/0x4f0
#1: ((&hdev->rx_work)){+.+.+.}, at: [<ffffffff8104d5f8>] process_one_work+0x258/0x4f0
#2: (&hdev->lock){+.+.+.}, at: [<ffffffffa000fbe9>] hci_disconn_complete_evt.isra.54+0x59/0x3c0 [bluetooth]
#3: (slock-AF_BLUETOOTH-BTPROTO_SCO){+.+...}, at: [<ffffffffa0033d5a>] sco_conn_del+0x8a/0xe0 [bluetooth]
stack backtrace:
Pid: 1018, comm: kworker/u:1H Not tainted 3.8.0-rc1+ #7
Call Trace:
[<ffffffff813e92f9>] print_circular_bug+0x1fb/0x20c
[<ffffffff81082215>] __lock_acquire+0x1465/0x1c70
[<ffffffff81083011>] lock_acquire+0xb1/0xe0
[<ffffffffa0033ba6>] ? sco_chan_del+0x66/0x190 [bluetooth]
[<ffffffff813efd01>] _raw_spin_lock+0x41/0x80
[<ffffffffa0033ba6>] ? sco_chan_del+0x66/0x190 [bluetooth]
[<ffffffffa0033ba6>] sco_chan_del+0x66/0x190 [bluetooth]
[<ffffffffa0033d6d>] sco_conn_del+0x9d/0xe0 [bluetooth]
[<ffffffffa0034653>] sco_disconn_cfm+0x53/0x60 [bluetooth]
[<ffffffffa000fef3>] hci_disconn_complete_evt.isra.54+0x363/0x3c0 [bluetooth]
[<ffffffffa000fbd0>] ? hci_disconn_complete_evt.isra.54+0x40/0x3c0 [bluetooth]
[<ffffffffa00150f7>] hci_event_packet+0xc7/0x29b0 [bluetooth]
[<ffffffff81202e90>] ? __dynamic_pr_debug+0x80/0x90
[<ffffffff8133ff7d>] ? kfree_skb+0x2d/0x40
[<ffffffffa0021644>] ? hci_send_to_monitor+0x1a4/0x1c0 [bluetooth]
[<ffffffffa0004583>] hci_rx_work+0x133/0x870 [bluetooth]
[<ffffffff8104d5f8>] ? process_one_work+0x258/0x4f0
[<ffffffff8104d65f>] process_one_work+0x2bf/0x4f0
[<ffffffff8104d5f8>] ? process_one_work+0x258/0x4f0
[<ffffffff8104fdc1>] ? worker_thread+0x51/0x3e0
[<ffffffffa0004450>] ? hci_tx_work+0x800/0x800 [bluetooth]
[<ffffffff81050022>] worker_thread+0x2b2/0x3e0
[<ffffffff8104fd70>] ? busy_worker_rebind_fn+0x100/0x100
[<ffffffff81056021>] kthread+0xd1/0xe0
[<ffffffff81055f50>] ? flush_kthread_worker+0xc0/0xc0
[<ffffffff813f14bc>] ret_from_fork+0x7c/0xb0
[<ffffffff81055f50>] ? flush_kthread_worker+0xc0/0xc0
Signed-off-by: Andre Guedes <andre.guedes@openbossa.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Checking only for sco_conn seems to not be enough and lead to NULL dereferences in the code, check for hcon instead. <1>[11340.226404] BUG: unable to handle kernel NULL pointer dereference at 0000000 8 <4>[11340.226619] EIP is at __sco_sock_close+0xe8/0x1a0 <4>[11340.226629] EAX: f063a740 EBX: 00000000 ECX: f58f4544 EDX: 00000000 <4>[11340.226640] ESI: dec83e00 EDI: 5f9a081f EBP: e0fdff38 ESP: e0fdff1c <0>[11340.226674] Stack: <4>[11340.226682] c184db87 c1251028 dec83e00 e0fdff38 c1754aef dec83e00 00000000 e0fdff5c <4>[11340.226718] c184f587 e0fdff64 e0fdff68 5f9a081f e0fdff5c c1751852 d7813800 62262f10 <4>[11340.226752] e0fdff70 c1753c00 00000000 00000001 0000000d e0fdffac c175425c 00000041 <0>[11340.226793] Call Trace: <4>[11340.226813] [<c184db87>] ? sco_sock_clear_timer+0x27/0x60 <4>[11340.226831] [<c1251028>] ? local_bh_enable+0x68/0xd0 <4>[11340.226846] [<c1754aef>] ? lock_sock_nested+0x4f/0x60 <4>[11340.226862] [<c184f587>] sco_sock_shutdown+0x67/0xb0 <4>[11340.226879] [<c1751852>] ? sockfd_lookup_light+0x22/0x80 <4>[11340.226897] [<c1753c00>] sys_shutdown+0x30/0x60 <4>[11340.226912] [<c175425c>] sys_socketcall+0x1dc/0x2a0 <4>[11340.226929] [<c149ba78>] ? trace_hardirqs_on_thunk+0xc/0x10 <4>[11340.226944] [<c18860f1>] syscall_call+0x7/0xb <4>[11340.226960] [<c1880000>] ? restore_cur+0x5e/0xd7 <0>[11340.226969] Code: <f0> ff 4b 08 0f 94 c0 84 c0 74 20 80 7b 19 01 74 2f b8 0a 00 00 Reported-by: Chuansheng Liu <chuansheng.liu@intel.com> Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
This reverts commit 269c4845d5b3627b95b1934107251bacbe99bb68. The commit was causing dead locks and NULL dereferences in the sco code: [28084.104013] BUG: soft lockup - CPU#0 stuck for 22s! [kworker/u:0H:7] [28084.104021] Modules linked in: btusb bluetooth <snip [last unloaded: bluetooth] ... [28084.104021] [<c160246d>] _raw_spin_lock+0xd/0x10 [28084.104021] [<f920e708>] sco_conn_del+0x58/0x1b0 [bluetooth] [28084.104021] [<f920f1a9>] sco_connect_cfm+0xb9/0x2b0 [bluetooth] [28084.104021] [<f91ef289>] hci_sync_conn_complete_evt.isra.94+0x1c9/0x260 [bluetooth] [28084.104021] [<f91f1a8d>] hci_event_packet+0x74d/0x2b40 [bluetooth] [28084.104021] [<c1501abd>] ? __kfree_skb+0x3d/0x90 [28084.104021] [<c1501b46>] ? kfree_skb+0x36/0x90 [28084.104021] [<f91fcb4e>] ? hci_send_to_monitor+0x10e/0x190 [bluetooth] [28084.104021] [<f91fcb4e>] ? hci_send_to_monitor+0x10e/0x190 [bluetooth] Cc: stable@vger.kernel.org Reported-by: Chan-yeol Park <chanyeol.park@gmail.com> Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
In order to authenticate and configure an incoming SCO connection, the BT_DEFER_SETUP option was added. This option is intended to defer reply to Connect Request on SCO sockets. When a connection is requested, the listening socket is unblocked but the effective connection setup happens only on first recv. Any send between accept and recv fails with -ENOTCONN. Signed-off-by: Frédéric Dalleau <frederic.dalleau@linux.intel.com> Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
This option will set the BT_SK_DEFER_SETUP bit in socket flags. Signed-off-by: Frédéric Dalleau <frederic.dalleau@linux.intel.com> Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Instead of old unsafe batostr function use %pMR print specifier for printing Bluetooth addresses in sprintf and seq_printf statements. Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com> Acked-by: Marcel Holtmann <marcel@holtmann.org> Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Instead of old unsafe batostr function use %pMR print specifier for printing Bluetooth addresses in debug and error statements. Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com> Acked-by: Marcel Holtmann <marcel@holtmann.org> Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
sco_chan_del() only has conn != NULL when called from sco_conn_del() so
just move the code from it that deal with conn to sco_conn_del().
[ 120.765529]
[ 120.765529] ======================================================
[ 120.766529] [ INFO: possible circular locking dependency detected ]
[ 120.766529] 3.5.0-rc1-10292-g3701f94-dirty #70 Tainted: G W
[ 120.766529] -------------------------------------------------------
[ 120.766529] kworker/u:3/1497 is trying to acquire lock:
[ 120.766529] (&(&conn->lock)->rlock#2){+.+...}, at:
[<ffffffffa00b7ecc>] sco_chan_del+0x4c/0x170 [bluetooth]
[ 120.766529]
[ 120.766529] but task is already holding lock:
[ 120.766529] (slock-AF_BLUETOOTH-BTPROTO_SCO){+.+...}, at:
[<ffffffffa00b8401>] sco_conn_del+0x61/0xe0 [bluetooth]
[ 120.766529]
[ 120.766529] which lock already depends on the new lock.
[ 120.766529]
[ 120.766529]
[ 120.766529] the existing dependency chain (in reverse order) is:
[ 120.766529]
[ 120.766529] -> #1 (slock-AF_BLUETOOTH-BTPROTO_SCO){+.+...}:
[ 120.766529] [<ffffffff8107980e>] lock_acquire+0x8e/0xb0
[ 120.766529] [<ffffffff813c19e0>] _raw_spin_lock+0x40/0x80
[ 120.766529] [<ffffffffa00b85e9>] sco_connect_cfm+0x79/0x300
[bluetooth]
[ 120.766529] [<ffffffffa0094b13>]
hci_sync_conn_complete_evt.isra.90+0x343/0x400 [bluetooth]
[ 120.766529] [<ffffffffa009d447>] hci_event_packet+0x317/0xfb0
[bluetooth]
[ 120.766529] [<ffffffffa008aa68>] hci_rx_work+0x2c8/0x890
[bluetooth]
[ 120.766529] [<ffffffff81047db7>] process_one_work+0x197/0x460
[ 120.766529] [<ffffffff810489d6>] worker_thread+0x126/0x2d0
[ 120.766529] [<ffffffff8104ee4d>] kthread+0x9d/0xb0
[ 120.766529] [<ffffffff813c4294>] kernel_thread_helper+0x4/0x10
[ 120.766529]
[ 120.766529] -> #0 (&(&conn->lock)->rlock#2){+.+...}:
[ 120.766529] [<ffffffff81078a8a>] __lock_acquire+0x154a/0x1d30
[ 120.766529] [<ffffffff8107980e>] lock_acquire+0x8e/0xb0
[ 120.766529] [<ffffffff813c19e0>] _raw_spin_lock+0x40/0x80
[ 120.766529] [<ffffffffa00b7ecc>] sco_chan_del+0x4c/0x170
[bluetooth]
[ 120.766529] [<ffffffffa00b8414>] sco_conn_del+0x74/0xe0
[bluetooth]
[ 120.766529] [<ffffffffa00b88a2>] sco_disconn_cfm+0x32/0x60
[bluetooth]
[ 120.766529] [<ffffffffa0093a82>]
hci_disconn_complete_evt.isra.53+0x242/0x390 [bluetooth]
[ 120.766529] [<ffffffffa009d747>] hci_event_packet+0x617/0xfb0
[bluetooth]
[ 120.766529] [<ffffffffa008aa68>] hci_rx_work+0x2c8/0x890
[bluetooth]
[ 120.766529] [<ffffffff81047db7>] process_one_work+0x197/0x460
[ 120.766529] [<ffffffff810489d6>] worker_thread+0x126/0x2d0
[ 120.766529] [<ffffffff8104ee4d>] kthread+0x9d/0xb0
[ 120.766529] [<ffffffff813c4294>] kernel_thread_helper+0x4/0x10
[ 120.766529]
[ 120.766529] other info that might help us debug this:
[ 120.766529]
[ 120.766529] Possible unsafe locking scenario:
[ 120.766529]
[ 120.766529] CPU0 CPU1
[ 120.766529] ---- ----
[ 120.766529] lock(slock-AF_BLUETOOTH-BTPROTO_SCO);
[ 120.766529]
lock(&(&conn->lock)->rlock#2);
[ 120.766529]
lock(slock-AF_BLUETOOTH-BTPROTO_SCO);
[ 120.766529] lock(&(&conn->lock)->rlock#2);
[ 120.766529]
[ 120.766529] *** DEADLOCK ***
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>