This patch adds 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.
Each USB bus gets a unique id, which can be used to attach a kcov device
to a particular USB bus for coverage collection.
Signed-off-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
---
drivers/usb/core/hub.c | 4 ++++
include/linux/kcov.h | 1 +
include/uapi/linux/kcov.h | 7 +++++++
3 files changed, 12 insertions(+)
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 236313f41f4a..03a40e41b099 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -5374,6 +5374,8 @@ static void hub_event(struct work_struct *work)
hub_dev = hub->intfdev;
intf = to_usb_interface(hub_dev);
+ kcov_remote_start(kcov_remote_handle_usb(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... */
@@ -5480,6 +5482,8 @@ static void hub_event(struct work_struct *work)
/* 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[] = {
diff --git a/include/linux/kcov.h b/include/linux/kcov.h
index 702672d98d35..38a47e0b67c2 100644
--- a/include/linux/kcov.h
+++ b/include/linux/kcov.h
@@ -30,6 +30,7 @@ void kcov_task_exit(struct task_struct *t);
/*
* Reserved handle ranges:
* 0000000000000000 - 0000ffffffffffff : common handles
+ * 0001000000000000 - 0001ffffffffffff : USB subsystem handles
*/
void kcov_remote_start(u64 handle);
void kcov_remote_stop(void);
diff --git a/include/uapi/linux/kcov.h b/include/uapi/linux/kcov.h
index 46f78f716ca9..45c9ae59cebc 100644
--- a/include/uapi/linux/kcov.h
+++ b/include/uapi/linux/kcov.h
@@ -43,4 +43,11 @@ enum {
#define KCOV_CMP_SIZE(n) ((n) << 1)
#define KCOV_CMP_MASK KCOV_CMP_SIZE(3)
+#define KCOV_REMOTE_HANDLE_USB 0x0001000000000000ull
+
+static inline __u64 kcov_remote_handle_usb(unsigned int bus)
+{
+ return KCOV_REMOTE_HANDLE_USB + (__u64)bus;
+}
+
#endif /* _LINUX_KCOV_IOCTLS_H */
--
2.23.0.866.gb869b98d4c-goog
