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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:38 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:38 +0000
commit08b74a000942a380fe028845f92cd3a0dee827d5 (patch)
treeaa78b4e12607c3e1fcce8d5cc42df4330792f118 /debian/patches-rt/0330-Bluetooth-Acquire-sk_lock.slock-without-disabling-in.patch
parentAdding upstream version 4.19.249. (diff)
downloadlinux-debian.tar.xz
linux-debian.zip
Adding debian version 4.19.249-2.debian/4.19.249-2debian
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r--debian/patches-rt/0330-Bluetooth-Acquire-sk_lock.slock-without-disabling-in.patch65
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
+