diff options
Diffstat (limited to 'debian/patches-rt/0330-Bluetooth-Acquire-sk_lock.slock-without-disabling-in.patch')
| -rw-r--r-- | debian/patches-rt/0330-Bluetooth-Acquire-sk_lock.slock-without-disabling-in.patch | 65 |
1 files changed, 65 insertions, 0 deletions
diff --git a/debian/patches-rt/0330-Bluetooth-Acquire-sk_lock.slock-without-disabling-in.patch b/debian/patches-rt/0330-Bluetooth-Acquire-sk_lock.slock-without-disabling-in.patch new file mode 100644 index 000000000..ff8d39cfc --- /dev/null +++ b/debian/patches-rt/0330-Bluetooth-Acquire-sk_lock.slock-without-disabling-in.patch @@ -0,0 +1,65 @@ +From ba289a24015e6e110bcc57dad832a8094be6b955 Mon Sep 17 00:00:00 2001 +From: Sebastian Andrzej Siewior <bigeasy@linutronix.de> +Date: Thu, 28 May 2020 14:35:12 +0200 +Subject: [PATCH 330/347] Bluetooth: Acquire sk_lock.slock without disabling + interrupts +Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.19/older/patches-4.19.246-rt110.tar.xz + +[ Upstream commit e6da0edc24eecef2f6964d92fa9044e1821deace ] + +There was a lockdep which led to commit + fad003b6c8e3d ("Bluetooth: Fix inconsistent lock state with RFCOMM") + +Lockdep noticed that `sk->sk_lock.slock' was acquired without disabling +the softirq while the lock was also used in softirq context. +Unfortunately the solution back then was to disable interrupts before +acquiring the lock which however made lockdep happy. +It would have been enough to simply disable the softirq. Disabling +interrupts before acquiring a spinlock_t is not allowed on PREEMPT_RT +because these locks are converted to 'sleeping' spinlocks. + +Use spin_lock_bh() in order to acquire the `sk_lock.slock'. + +Reported-by: Luis Claudio R. Goncalves <lclaudio@uudg.org> +Reported-by: kbuild test robot <lkp@intel.com> [missing unlock] +Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> +Signed-off-by: Marcel Holtmann <marcel@holtmann.org> +Signed-off-by: Tom Zanussi <zanussi@kernel.org> +--- + net/bluetooth/rfcomm/sock.c | 7 ++----- + 1 file changed, 2 insertions(+), 5 deletions(-) + +diff --git a/net/bluetooth/rfcomm/sock.c b/net/bluetooth/rfcomm/sock.c +index c044ff2f73e6..75bc8102cdd7 100644 +--- a/net/bluetooth/rfcomm/sock.c ++++ b/net/bluetooth/rfcomm/sock.c +@@ -64,15 +64,13 @@ static void rfcomm_sk_data_ready(struct rfcomm_dlc *d, struct sk_buff *skb) + static void rfcomm_sk_state_change(struct rfcomm_dlc *d, int err) + { + struct sock *sk = d->owner, *parent; +- unsigned long flags; + + if (!sk) + return; + + BT_DBG("dlc %p state %ld err %d", d, d->state, err); + +- local_irq_save(flags); +- bh_lock_sock(sk); ++ spin_lock_bh(&sk->sk_lock.slock); + + if (err) + sk->sk_err = err; +@@ -93,8 +91,7 @@ static void rfcomm_sk_state_change(struct rfcomm_dlc *d, int err) + sk->sk_state_change(sk); + } + +- bh_unlock_sock(sk); +- local_irq_restore(flags); ++ spin_unlock_bh(&sk->sk_lock.slock); + + if (parent && sock_flag(sk, SOCK_ZAPPED)) { + /* We have to drop DLC lock here, otherwise +-- +2.36.1 + |