diff mbox series

[v1,3/3] usb: core: kcov: collect coverage from usb complete callback

Message ID d440a200cc1a3faddfd429467ac42841ee002bbc.1582742673.git.andreyknvl@google.com (mailing list archive)
State Superseded
Headers show
Series kcov: collect coverage from usb soft interrupts | expand

Commit Message

Andrey Konovalov Feb. 26, 2020, 6:48 p.m. UTC
This patch adds kcov_remote_start/stop() callbacks around the urb
complete() callback that is executed in softirq context when dummy_hcd
is in use. As the result, kcov can be used to collect coverage from those
those callbacks, which is used to facilitate coverage-guided fuzzing with
syzkaller.

Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
---
 drivers/usb/core/hcd.c | 3 +++
 1 file changed, 3 insertions(+)
diff mbox series

Patch

diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
index aa45840d8273..de624c47e190 100644
--- a/drivers/usb/core/hcd.c
+++ b/drivers/usb/core/hcd.c
@@ -31,6 +31,7 @@ 
 #include <linux/types.h>
 #include <linux/genalloc.h>
 #include <linux/io.h>
+#include <linux/kcov.h>
 
 #include <linux/phy/phy.h>
 #include <linux/usb.h>
@@ -1645,7 +1646,9 @@  static void __usb_hcd_giveback_urb(struct urb *urb)
 
 	/* pass ownership to the completion handler */
 	urb->status = status;
+	kcov_remote_start_usb((u64)urb->dev->bus->busnum);
 	urb->complete(urb);
+	kcov_remote_stop();
 
 	usb_anchor_resume_wakeups(anchor);
 	atomic_dec(&urb->use_count);