From: Andrey Konovalov <andreyknvl@xxxxxxxxxx> Subject: usb, kcov: collect coverage from hub_event Add kcov_remote_start()/kcov_remote_stop() annotations to the hub_event() function, which is responsible for processing events on USB buses, in particular events that happen during USB device enumeration. Since hub_event() is run in a global background kernel thread (see Documentation/dev-tools/kcov.rst for details), each USB bus gets a unique global handle from the USB subsystem kcov handle range. As the result kcov can now be used to collect coverage from events that happen on a particular USB bus. [akpm@xxxxxxxxxxxxxxxxxxxx: avoid patch conflicts to make life easier for Andrew] Link: http://lkml.kernel.org/r/de4fe1c219db2d002d905dc1736e2a3bfa1db997.1572366574.git.andreyknvl@xxxxxxxxxx Signed-off-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx> Reviewed-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Cc: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> Cc: Alexander Potapenko <glider@xxxxxxxxxx> Cc: Anders Roxell <anders.roxell@xxxxxxxxxx> Cc: Arnd Bergmann <arnd@xxxxxxxx> Cc: David Windsor <dwindsor@xxxxxxxxx> Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx> Cc: Elena Reshetova <elena.reshetova@xxxxxxxxx> Cc: Jason Wang <jasowang@xxxxxxxxxx> Cc: Marco Elver <elver@xxxxxxxxxx> Cc: "Michael S. Tsirkin" <mst@xxxxxxxxxx> Cc: Steven Rostedt <rostedt@xxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- drivers/usb/core/hub.c | 5 +++++ 1 file changed, 5 insertions(+) --- a/drivers/usb/core/hub.c~usb-kcov-collect-coverage-from-hub_event +++ a/drivers/usb/core/hub.c @@ -18,6 +18,7 @@ #include <linux/sched/mm.h> #include <linux/list.h> #include <linux/slab.h> +#include <linux/kcov.h> #include <linux/ioctl.h> #include <linux/usb.h> #include <linux/usbdevice_fs.h> @@ -5484,6 +5485,8 @@ static void hub_event(struct work_struct hub_dev = hub->intfdev; intf = to_usb_interface(hub_dev); + kcov_remote_start_usb((u64)hdev->bus->busnum); + dev_dbg(hub_dev, "state %d ports %d chg %04x evt %04x\n", hdev->state, hdev->maxchild, /* NOTE: expects max 15 ports... */ @@ -5590,6 +5593,8 @@ out_hdev_lock: /* Balance the stuff in kick_hub_wq() and allow autosuspend */ usb_autopm_put_interface(intf); kref_put(&hub->kref, hub_release); + + kcov_remote_stop(); } static const struct usb_device_id hub_id_table[] = { _
