Nick Pelly wrote:
On Sat, Feb 20, 2010 at 12:17 AM, Dave Young <hidave.darkstar@xxxxxxxxx> wrote:
On Thu, Feb 18, 2010 at 1:04 PM, Nick Pelly <npelly@xxxxxxxxxx> wrote:
Since 2.6.32 we are seeing kernel panics like:
[10651.110229] Unable to handle kernel paging request at virtual
address 6b6b6b6b
[10651.111968] Internal error: Oops: 5 [#1] PREEMPT
[10651.113952] CPU: 0 Tainted: G W (2.6.32-59979-gd0c97db #1)
[10651.114624] PC is at rfcomm_run+0xa04/0xdbc
<...>
[10651.406188] [<c031ad24>] (rfcomm_run+0xa04/0xdbc) from [<c006ce30>]
(kthread+0x78/0x80)
[10651.406585] [<c006ce30>] (kthread+0x78/0x80) from [<c002793c>]
(kernel_thread_exit+0x0/0x8)
(rfcomm_run() is all inlined so theres not much of a stack trace))
l2cap socket status might change while rfcomm is processing frames. And
that makes rfcomm_process_rx to do double rfcomm_session_put() for
incoming session reference. We cannot use sk_state.
Could you try with this patch if it helps to your problems also? My OPP
problems went away with this patch.
I moved rfcomm_session_put() for incoming session to
rfcomm_session_close in order to get more clear _hold()/_put() pairs.
--
Ville
>From e713b2e8ae93aa46465984237247698d18f6a671 Mon Sep 17 00:00:00 2001
From: Ville Tervo <ville.tervo@xxxxxxxxx>
Date: Fri, 26 Feb 2010 12:21:01 +0200
Subject: [PATCH] Bluetooth: Drop rfcomm session reference only once for incoming session
Move decision to drop reference for incoming session to
rfcomm_session_close to get more clear
rfcomm_session_hold()/rfcomm_session_put() pairs.
Signed-off-by: Ville Tervo <ville.tervo@xxxxxxxxx>
---
net/bluetooth/rfcomm/core.c | 23 ++++++++++-------------
1 files changed, 10 insertions(+), 13 deletions(-)
diff --git a/net/bluetooth/rfcomm/core.c b/net/bluetooth/rfcomm/core.c
index 89f4a59..adccd92 100644
--- a/net/bluetooth/rfcomm/core.c
+++ b/net/bluetooth/rfcomm/core.c
@@ -662,6 +662,9 @@ static void rfcomm_session_close(struct rfcomm_session *s, int err)
BT_DBG("session %p state %ld err %d", s, s->state, err);
+ if (s->state == BT_CLOSED)
+ return;
+
rfcomm_session_hold(s);
s->state = BT_CLOSED;
@@ -674,6 +677,11 @@ static void rfcomm_session_close(struct rfcomm_session *s, int err)
}
rfcomm_session_clear_timer(s);
+
+ /* Drop reference for incoming sessions */
+ if (!s->initiator)
+ rfcomm_session_put(s);
+
rfcomm_session_put(s);
}
@@ -1150,11 +1158,7 @@ static int rfcomm_recv_ua(struct rfcomm_session *s, u8 dlci)
break;
case BT_DISCONN:
- /* When socket is closed and we are not RFCOMM
- * initiator rfcomm_process_rx already calls
- * rfcomm_session_put() */
- if (s->sock->sk->sk_state != BT_CLOSED)
- rfcomm_session_put(s);
+ rfcomm_session_close(s, 0);
break;
}
}
@@ -1185,7 +1189,6 @@ static int rfcomm_recv_dm(struct rfcomm_session *s, u8 dlci)
else
err = ECONNRESET;
- s->state = BT_CLOSED;
rfcomm_session_close(s, err);
}
return 0;
@@ -1220,7 +1223,6 @@ static int rfcomm_recv_disc(struct rfcomm_session *s, u8 dlci)
else
err = ECONNRESET;
- s->state = BT_CLOSED;
rfcomm_session_close(s, err);
}
@@ -1845,12 +1847,8 @@ static inline void rfcomm_process_rx(struct rfcomm_session *s)
rfcomm_recv_frame(s, skb);
}
- if (sk->sk_state == BT_CLOSED) {
- if (!s->initiator)
- rfcomm_session_put(s);
-
+ if (sk->sk_state == BT_CLOSED)
rfcomm_session_close(s, sk->sk_err);
- }
}
static inline void rfcomm_accept_connection(struct rfcomm_session *s)
@@ -1904,7 +1902,6 @@ static inline void rfcomm_check_connection(struct rfcomm_session *s)
break;
case BT_CLOSED:
- s->state = BT_CLOSED;
rfcomm_session_close(s, sk->sk_err);
break;
}
--
1.6.4.4
