[PATCH v7 1/4] [v6 fix] mfd/rtsx_usb: fix possible race condition

rogerable
2014-04-11T06:53:20Z

From: Roger Tseng <rogerable@realtek.com>

Fix two possible race condition generated by misuse of del_timer in
rtsx_usb_bulk_transfer_sglist() and uninitialized timers before mfd_add_devices
in rtsx_usb_probe().

Signed-off-by: Roger Tseng <rogerable@realtek.com>
---
drivers/mfd/rtsx_usb.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/mfd/rtsx_usb.c b/drivers/mfd/rtsx_usb.c
index b53b9d4..0ca7973 100644
--- a/drivers/mfd/rtsx_usb.c
+++ b/drivers/mfd/rtsx_usb.c
@@ -67,7 +67,7 @@ static int rtsx_usb_bulk_transfer_sglist(struct rtsx_ucr *ucr,
ucr->sg_timer.expires = jiffies + msecs_to_jiffies(timeout);
add_timer(&ucr->sg_timer);
usb_sg_wait(&ucr->current_sg);
- del_timer(&ucr->sg_timer);
+ del_timer_sync(&ucr->sg_timer);

if (act_len)
*act_len = ucr->current_sg.bytes;
@@ -644,14 +644,14 @@ static int rtsx_usb_probe(struct usb_interface *intf,
if (ret)
goto out_init_fail;

+ /* initialize USB SG transfer timer */
+ setup_timer(&ucr->sg_timer, rtsx_usb_sg_timed_out, (unsigned long) ucr);
+
ret = mfd_add_devices(&intf->dev, usb_dev->devnum, rtsx_usb_cells,
ARRAY_SIZE(rtsx_usb_cells), NULL, 0, NULL);
if (ret)
goto out_init_fail;

- /* initialize USB SG transfer timer */
- init_timer(&ucr->sg_timer);
- setup_timer(&ucr->sg_timer, rtsx_usb_sg_timed_out, (unsigned long) ucr);
#ifdef CONFIG_PM
intf->needs_remote_wakeup = 1;
usb_enable_autosuspend(usb_dev);
--
1.8.2