diff options
| author | UCHINO Satoshi <satoshi.uchino@toshiba.co.jp> | 2013-05-23 11:10:11 +0900 |
|---|---|---|
| committer | Felipe Balbi <balbi@ti.com> | 2013-06-10 17:10:34 +0300 |
| commit | d68c277b501889b3a50c179d1c3d704db7947b83 (patch) | |
| tree | 6d3b81f4a3279c32f353184dc744697b33f2f958 | |
| parent | eb127cb519d73c0d0e8089dcbde8c94dc1fc7e20 (diff) | |
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>
| -rw-r--r-- | drivers/usb/gadget/f_mass_storage.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/usb/gadget/f_mass_storage.c b/drivers/usb/gadget/f_mass_storage.c index 97666e8b1b95..c35a9ecc576b 100644 --- a/drivers/usb/gadget/f_mass_storage.c +++ b/drivers/usb/gadget/f_mass_storage.c @@ -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; } |