Re: [PATCH] usbip, kcov: collect coverage from usbip client

[Andrey Konovalov <andreyknvl@google.com>]

On Sat, Oct 10, 2020 at 8:55 AM Greg Kroah-Hartman
<gregkh@linuxfoundation.org> wrote:
>
> On Fri, Oct 09, 2020 at 03:22:55PM +0000, NazimeHandeHarputluogluhandeharput@gmail.com wrote:
> > From: Nazime Hande Harputluoglu <handeharputlu@google.com>
> >
> > Add kcov_remote_start()/kcov_remote_stop() annotations to the
> > vhci_rx_loop() function, which is responsible for parsing USB/IP packets
> > in USB/IP client.
> >
> > Since vhci_rx_loop() threads are spawned per usbip device instance, the
> > common kcov handle is used for kcov_remote_start()/stop() annotations
> > (see Documentation/dev-tools/kcov.rst for details). As the result kcov
> > can now be used to collect coverage from vhci_rx_loop() threads.
> >
> > Signed-off-by: Nazime Hande Harputluoglu <handeharputlu@google.com>
> > ---
> >  drivers/usb/usbip/usbip_common.h | 2 ++
> >  drivers/usb/usbip/vhci_rx.c      | 6 ++++--
> >  drivers/usb/usbip/vhci_sysfs.c   | 2 ++
> >  3 files changed, 8 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/usb/usbip/usbip_common.h b/drivers/usb/usbip/usbip_common.h
> > index 8be857a4fa13..cbbf2aa8ac73 100644
> > --- a/drivers/usb/usbip/usbip_common.h
> > +++ b/drivers/usb/usbip/usbip_common.h
> > @@ -277,6 +277,8 @@ struct usbip_device {
> >               void (*reset)(struct usbip_device *);
> >               void (*unusable)(struct usbip_device *);
> >       } eh_ops;
> > +
> > +        u64 kcov_handle;
> >  };
> >
> >  #define kthread_get_run(threadfn, data, namefmt, ...)                           \
> > diff --git a/drivers/usb/usbip/vhci_rx.c b/drivers/usb/usbip/vhci_rx.c
> > index 266024cbb64f..b2eb3e8c04b9 100644
> > --- a/drivers/usb/usbip/vhci_rx.c
> > +++ b/drivers/usb/usbip/vhci_rx.c
> > @@ -260,8 +260,10 @@ int vhci_rx_loop(void *data)
> >       while (!kthread_should_stop()) {
> >               if (usbip_event_happened(ud))
> >                       break;
> > -
> > -             vhci_rx_pdu(ud);
> > +
> > +                kcov_remote_start_common(ud->kcov_handle);
> > +                vhci_rx_pdu(ud);
> > +                kcov_remote_stop();
> >       }
> >
> >       return 0;
> > diff --git a/drivers/usb/usbip/vhci_sysfs.c b/drivers/usb/usbip/vhci_sysfs.c
> > index be37aec250c2..4dfe3809ebbb 100644
> > --- a/drivers/usb/usbip/vhci_sysfs.c
> > +++ b/drivers/usb/usbip/vhci_sysfs.c
> > @@ -9,6 +9,7 @@
> >  #include <linux/net.h>
> >  #include <linux/platform_device.h>
> >  #include <linux/slab.h>
> > +#include <linux/kcov.h>
> >
> >  /* Hardening for Spectre-v1 */
> >  #include <linux/nospec.h>
> > @@ -383,6 +384,7 @@ static ssize_t attach_store(struct device *dev, struct device_attribute *attr,
> >       vdev->ud.sockfd     = sockfd;
> >       vdev->ud.tcp_socket = socket;
> >       vdev->ud.status     = VDEV_ST_NOTASSIGNED;
> > +        vdev->ud.kcov_handle = kcov_common_handle();
> >
> >       spin_unlock(&vdev->ud.lock);
> >       spin_unlock_irqrestore(&vhci->lock, flags);
> > --
> > 2.28.0.1011.ga647a8990f-goog
> >
>
> Please run checkpatch.pl on your patches before sending them out, so you
> don't get grumpy maintainers telling you to run checkpatch.pl on your
> patch...

Hi Greg,

Sorry, I'll fix it up and send v2.

Thanks!