From a85830a89dc3b0ef7f2df78cf42d6ae4baa456db Mon Sep 17 00:00:00 2001 From: hselasky Date: Fri, 3 Jun 2016 08:55:28 +0000 Subject: [PATCH] MFC r300667: Check for signals when locking the USB enumeration thread from userspace, so that USB applications can be killed if an enumeration thread should be stuck for various reasons. git-svn-id: svn://svn.freebsd.org/base/stable/10@301253 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f --- sys/dev/usb/usb_dev.c | 8 +++++++- sys/dev/usb/usb_device.c | 23 ++++++++++++++++++++++- sys/dev/usb/usb_device.h | 3 +++ 3 files changed, 32 insertions(+), 2 deletions(-) diff --git a/sys/dev/usb/usb_dev.c b/sys/dev/usb/usb_dev.c index 723123043..2973fa46f 100644 --- a/sys/dev/usb/usb_dev.c +++ b/sys/dev/usb/usb_dev.c @@ -229,7 +229,7 @@ usb_ref_device(struct usb_cdev_privdata *cpd, * We need to grab the enumeration SX-lock before * grabbing the FIFO refs to avoid deadlock at detach! */ - crd->do_unlock = usbd_enum_lock(cpd->udev); + crd->do_unlock = usbd_enum_lock_sig(cpd->udev); mtx_lock(&usb_ref_lock); @@ -237,6 +237,12 @@ usb_ref_device(struct usb_cdev_privdata *cpd, * Set "is_uref" after grabbing the default SX lock */ crd->is_uref = 1; + + /* check for signal */ + if (crd->do_unlock > 1) { + crd->do_unlock = 0; + goto error; + } } /* check if we are doing an open */ diff --git a/sys/dev/usb/usb_device.c b/sys/dev/usb/usb_device.c index bd62009e8..639d46102 100644 --- a/sys/dev/usb/usb_device.c +++ b/sys/dev/usb/usb_device.c @@ -2740,7 +2740,7 @@ usbd_device_attached(struct usb_device *udev) /* * The following function locks enumerating the given USB device. If * the lock is already grabbed this function returns zero. Else a - * non-zero value is returned. + * a value of one is returned. */ uint8_t usbd_enum_lock(struct usb_device *udev) @@ -2759,6 +2759,27 @@ usbd_enum_lock(struct usb_device *udev) return (1); } +#if USB_HAVE_UGEN +/* + * This function is the same like usbd_enum_lock() except a value of + * 255 is returned when a signal is pending: + */ +uint8_t +usbd_enum_lock_sig(struct usb_device *udev) +{ + if (sx_xlocked(&udev->enum_sx)) + return (0); + if (sx_xlock_sig(&udev->enum_sx)) + return (255); + if (sx_xlock_sig(&udev->sr_sx)) { + sx_xunlock(&udev->enum_sx); + return (255); + } + mtx_lock(&Giant); + return (1); +} +#endif + /* The following function unlocks enumerating the given USB device. */ void diff --git a/sys/dev/usb/usb_device.h b/sys/dev/usb/usb_device.h index 5a9499805..7a979bb4a 100644 --- a/sys/dev/usb/usb_device.h +++ b/sys/dev/usb/usb_device.h @@ -314,6 +314,9 @@ void usb_set_device_state(struct usb_device *, enum usb_dev_state); enum usb_dev_state usb_get_device_state(struct usb_device *); uint8_t usbd_enum_lock(struct usb_device *); +#if USB_HAVE_UGEN +uint8_t usbd_enum_lock_sig(struct usb_device *); +#endif void usbd_enum_unlock(struct usb_device *); void usbd_sr_lock(struct usb_device *); void usbd_sr_unlock(struct usb_device *); -- 2.45.0