Re: [PATCH v2 3/3] usb: core: kcov: collect coverage from usb complete callback

From: Peter Chen
Date: Thu Mar 12 2020 - 05:39:23 EST


On 20-03-09 19:27:06, Andrey Konovalov wrote:
> 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

Typo, One more "those"

Peter

> syzkaller.
>
> Signed-off-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
> ---
> drivers/usb/core/hcd.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> 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);
> --
> 2.25.1.481.gfbce0eb801-goog
>

--

Thanks,
Peter Chen