usb: gadget: r8a66597: Fix two possible sleep-in-atomic-context bugs in init_controller()
authorJia-Ju Bai <baijiaju1990@gmail.com>
Wed, 20 Jun 2018 03:54:53 +0000 (11:54 +0800)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Wed, 5 Sep 2018 07:20:00 +0000 (09:20 +0200)
commit62dd6eda364145ddc918e771a4fc47017ce809cb
treea5fe70a85438b6222494ecfe31cc4223464fdea1
parent13f03bd19c9b7af30ddd12283a6345b0f88eb7e0
usb: gadget: r8a66597: Fix two possible sleep-in-atomic-context bugs in init_controller()

[ Upstream commit 0602088b10a7c0b4e044a810678ef93d7cc5bf48 ]

The driver may sleep with holding a spinlock.
The function call paths (from bottom to top) in Linux-4.16.7 are:

[FUNC] msleep
drivers/usb/gadget/udc/r8a66597-udc.c, 839:
msleep in init_controller
drivers/usb/gadget/udc/r8a66597-udc.c, 96:
init_controller in r8a66597_usb_disconnect
drivers/usb/gadget/udc/r8a66597-udc.c, 93:
spin_lock in r8a66597_usb_disconnect

[FUNC] msleep
drivers/usb/gadget/udc/r8a66597-udc.c, 835:
msleep in init_controller
drivers/usb/gadget/udc/r8a66597-udc.c, 96:
init_controller in r8a66597_usb_disconnect
drivers/usb/gadget/udc/r8a66597-udc.c, 93:
spin_lock in r8a66597_usb_disconnect

To fix these bugs, msleep() is replaced with mdelay().

This bug is found by my static analysis tool (DSAC-2) and checked by
my code review.

Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/usb/gadget/udc/r8a66597-udc.c