From: Johannes Berg johannes.berg@intel.com
[ Upstream commit f2d05059e15af3f70502074f4e3a504530af504a ]
Lockdep complains at boot:
============================= [ BUG: Invalid wait context ] 5.7.0-05093-g46d91ecd597b #98 Not tainted ----------------------------- swapper/1 is trying to lock: 0000000060931b98 (&desc[i].request_mutex){+.+.}-{3:3}, at: __setup_irq+0x11d/0x623 other info that might help us debug this: context-{4:4} 1 lock held by swapper/1: #0: 000000006074fed8 (sigio_spinlock){+.+.}-{2:2}, at: sigio_lock+0x1a/0x1c stack backtrace: CPU: 0 PID: 1 Comm: swapper Not tainted 5.7.0-05093-g46d91ecd597b #98 Stack: 7fa4fab0 6028dfd1 0000002a 6008bea5 7fa50700 7fa50040 7fa4fac0 6028e016 7fa4fb50 6007f6da 60959c18 00000000 Call Trace: [<60023a0e>] show_stack+0x13b/0x155 [<6028e016>] dump_stack+0x2a/0x2c [<6007f6da>] __lock_acquire+0x515/0x15f2 [<6007eb50>] lock_acquire+0x245/0x273 [<6050d9f1>] __mutex_lock+0xbd/0x325 [<6050dc76>] mutex_lock_nested+0x1d/0x1f [<6008e27e>] __setup_irq+0x11d/0x623 [<6008e8ed>] request_threaded_irq+0x169/0x1a6 [<60021eb0>] um_request_irq+0x1ee/0x24b [<600234ee>] write_sigio_irq+0x3b/0x76 [<600383ca>] sigio_broken+0x146/0x2e4 [<60020bd8>] do_one_initcall+0xde/0x281
Because we hold sigio_spinlock and then get into requesting an interrupt with a mutex.
Change the spinlock to a mutex to avoid that.
Signed-off-by: Johannes Berg johannes.berg@intel.com Signed-off-by: Richard Weinberger richard@nod.at Signed-off-by: Sasha Levin sashal@kernel.org --- arch/um/kernel/sigio.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/arch/um/kernel/sigio.c b/arch/um/kernel/sigio.c index b5e0cbb343828..476ded92affac 100644 --- a/arch/um/kernel/sigio.c +++ b/arch/um/kernel/sigio.c @@ -36,14 +36,14 @@ int write_sigio_irq(int fd) }
/* These are called from os-Linux/sigio.c to protect its pollfds arrays. */ -static DEFINE_SPINLOCK(sigio_spinlock); +static DEFINE_MUTEX(sigio_mutex);
void sigio_lock(void) { - spin_lock(&sigio_spinlock); + mutex_lock(&sigio_mutex); }
void sigio_unlock(void) { - spin_unlock(&sigio_spinlock); + mutex_unlock(&sigio_mutex); }