[PATCH 4.19 023/118] Revert "usb: gadget: ffs: Fix BUG when userland exits with submitted AIO transfers"

Greg Kroah-Hartman
2018-12-11T15:54:47Z

[ Upstream commit a9c859033f6ec772f8e3228c343bb1321584ae0e ]

This reverts commit b4194da3f9087dd38d91b40f9bec42d59ce589a8
since it causes list corruption followed by kernel panic:

Workqueue: adb ffs_aio_cancel_worker
RIP: 0010:__list_add_valid+0x4d/0x70
Call Trace:
insert_work+0x47/0xb0
__queue_work+0xf6/0x400
queue_work_on+0x65/0x70
dwc3_gadget_giveback+0x44/0x50 [dwc3]
dwc3_gadget_ep_dequeue+0x83/0x2d0 [dwc3]
? finish_wait+0x80/0x80
usb_ep_dequeue+0x1e/0x90
process_one_work+0x18c/0x3b0
worker_thread+0x3c/0x390
? process_one_work+0x3b0/0x3b0
kthread+0x11e/0x140
? kthread_create_worker_on_cpu+0x70/0x70
ret_from_fork+0x3a/0x50

This issue is seen with warm reboot stability testing.

Signed-off-by: Shen Jing <jingx.shen@intel.com>
Signed-off-by: Saranya Gopal <saranya.gopal@intel.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/usb/gadget/function/f_fs.c | 26 ++++++++------------------
1 file changed, 8 insertions(+), 18 deletions(-)

diff --git a/drivers/usb/gadget/function/f_fs.c b/drivers/usb/gadget/function/f_fs.c
index 3ada83d81bda..31e8bf3578c8 100644
--- a/drivers/usb/gadget/function/f_fs.c
+++ b/drivers/usb/gadget/function/f_fs.c
@@ -215,7 +215,6 @@ struct ffs_io_data {

struct mm_struct *mm;
struct work_struct work;
- struct work_struct cancellation_work;

struct usb_ep *ep;
struct usb_request *req;
@@ -1073,31 +1072,22 @@ ffs_epfile_open(struct inode *inode, struct file *file)
return 0;
}

-static void ffs_aio_cancel_worker(struct work_struct *work)
-{
- struct ffs_io_data *io_data = container_of(work, struct ffs_io_data,
- cancellation_work);
-
- ENTER();
-
- usb_ep_dequeue(io_data->ep, io_data->req);
-}
-
static int ffs_aio_cancel(struct kiocb *kiocb)
{
struct ffs_io_data *io_data = kiocb->private;
- struct ffs_data *ffs = io_data->ffs;
+ struct ffs_epfile *epfile = kiocb->ki_filp->private_data;
int value;

ENTER();

- if (likely(io_data && io_data->ep && io_data->req)) {
- INIT_WORK(&io_data->cancellation_work, ffs_aio_cancel_worker);
- queue_work(ffs->io_completion_wq, &io_data->cancellation_work);
- value = -EINPROGRESS;
- } else {
+ spin_lock_irq(&epfile->ffs->eps_lock);
+
+ 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);

return value;
}
--
2.19.1