usb: gadget: f_mass_storage: add missing memory barrier for thread_wakeup_needed
Without this memory barrier, the file-storage thread may fail to escape from the following while loop, because it may observe new common->thread_wakeup_needed and old bh->state which are updated by the callback functions. /* Wait for the CBW to arrive */ while (bh->state != BUF_STATE_FULL) { rc = sleep_thread(common); if (rc) return rc; } Cc: stable@vger.kernel.org Signed-off-by: UCHINO Satoshi <satoshi.uchino@toshiba.co.jp> Acked-by: Michal Nazarewicz <mina86@mina86.com> Signed-off-by: Felipe Balbi <balbi@ti.com>
This commit is contained in:
parent
eb127cb519
commit
d68c277b50
|
@ -413,6 +413,7 @@ static int fsg_set_halt(struct fsg_dev *fsg, struct usb_ep *ep)
|
|||
/* Caller must hold fsg->lock */
|
||||
static void wakeup_thread(struct fsg_common *common)
|
||||
{
|
||||
smp_wmb(); /* ensure the write of bh->state is complete */
|
||||
/* Tell the main thread that something has happened */
|
||||
common->thread_wakeup_needed = 1;
|
||||
if (common->thread_task)
|
||||
|
@ -632,6 +633,7 @@ static int sleep_thread(struct fsg_common *common)
|
|||
}
|
||||
__set_current_state(TASK_RUNNING);
|
||||
common->thread_wakeup_needed = 0;
|
||||
smp_rmb(); /* ensure the latest bh->state is visible */
|
||||
return rc;
|
||||
}
|
||||
|
||||
|
|
Loading…
Reference in a new issue