[PATCH AUTOSEL 4.9 03/13] usb: gadget: ffs: ffs_aio_cancel(): Save/restore IRQ flags

Sasha Levin
2020-03-03T02:50:11Z

From: Lars-Peter Clausen <lars@metafoo.de>

[ Upstream commit 43d565727a3a6fd24e37c7c2116475106af71806 ]

ffs_aio_cancel() can be called from both interrupt and thread context. Make
sure that the current IRQ state is saved and restored by using
spin_{un,}lock_irq{save,restore}().

Otherwise undefined behavior might occur.

Acked-by: Michal Nazarewicz <mina86@mina86.com>
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Signed-off-by: Felipe Balbi <balbi@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/usb/gadget/function/f_fs.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/gadget/function/f_fs.c b/drivers/usb/gadget/function/f_fs.c
index d1278d2d544b4..b5747f1270a6d 100644
--- a/drivers/usb/gadget/function/f_fs.c
+++ b/drivers/usb/gadget/function/f_fs.c
@@ -1077,18 +1077,19 @@ static int ffs_aio_cancel(struct kiocb *kiocb)
{
struct ffs_io_data *io_data = kiocb->private;
struct ffs_epfile *epfile = kiocb->ki_filp->private_data;
+ unsigned long flags;
int value;

ENTER();

- spin_lock_irq(&epfile->ffs->eps_lock);
+ spin_lock_irqsave(&epfile->ffs->eps_lock, flags);

if (likely(io_data && io_data->ep && io_data->req))
value = usb_ep_dequeue(io_data->ep, io_data->req);
else
value = -EINVAL;

- spin_unlock_irq(&epfile->ffs->eps_lock);
+ spin_unlock_irqrestore(&epfile->ffs->eps_lock, flags);

return value;
}
--
2.20.1