Re: [PATCH v3] kcov, usbip: collect coverage from vhci_rx_loop

[Andrey Konovalov <andreyknvl@google.com>]

On Mon, Oct 19, 2020 at 8:52 PM Shuah Khan <skhan@linuxfoundation.org> wrote:
>
> On 10/19/20 12:49 PM, Shuah Khan wrote:
> > On 10/19/20 11:20 AM, Andrey Konovalov 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
> >> coming into USB/IP client.
> >>
> >> Since vhci_rx_loop() threads are spawned per vhci_hcd 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>
> >> Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
> >> ---
> >>
> >> Changes v2->v3:
> >> - Fix build without KCOV enabled.
> >>
> >> ---
> >>   drivers/usb/usbip/usbip_common.h | 4 ++++
> >>   drivers/usb/usbip/vhci_rx.c      | 7 +++++++
> >>   drivers/usb/usbip/vhci_sysfs.c   | 4 ++++
> >>   3 files changed, 15 insertions(+)
> >>
> >> diff --git a/drivers/usb/usbip/usbip_common.h
> >> b/drivers/usb/usbip/usbip_common.h
> >> index 8be857a4fa13..0906182011d6 100644
> >> --- a/drivers/usb/usbip/usbip_common.h
> >> +++ b/drivers/usb/usbip/usbip_common.h
> >> @@ -277,6 +277,10 @@ struct usbip_device {
> >>           void (*reset)(struct usbip_device *);
> >>           void (*unusable)(struct usbip_device *);
> >>       } eh_ops;
> >> +
> >> +#ifdef CONFIG_KCOV
> >> +    u64 kcov_handle;
> >> +#endif
> >>   };
> >>   #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..68ec0aa64f69 100644
> >> --- a/drivers/usb/usbip/vhci_rx.c
> >> +++ b/drivers/usb/usbip/vhci_rx.c
> >> @@ -3,6 +3,7 @@
> >>    * Copyright (C) 2003-2008 Takahiro Hirofuchi
> >>    */
> >> +#include <linux/kcov.h>
> >>   #include <linux/kthread.h>
> >>   #include <linux/slab.h>
> >> @@ -261,7 +262,13 @@ int vhci_rx_loop(void *data)
> >>           if (usbip_event_happened(ud))
> >>               break;
> >> +#ifdef CONFIG_KCOV
> >> +        kcov_remote_start_common(ud->kcov_handle);
> >> +#endif
> >>           vhci_rx_pdu(ud);
> >> +#ifdef CONFIG_KCOV
> >> +        kcov_remote_stop();
> >> +#endif
> >>       }
> >
> > Let's move these into usbip_common.h as inline functions along
> > the line of
> >
> > #ifdef CONFIG_KCOV
> > usbip_kcov_remote_start_common(ud)
> > {
> >    kcov_remote_start_common(ud->kcov_handle);
> > }
> >
> > usbip_kcov_remote_stop_common(ud)
> > {
> >    kcov_remote_stop_common(ud->kcov_handle);
> > }
> > #else
> > stubs that do nothing
> > #endif

Sounds good, will mail a new version shortly. Sorry for a delay, I was
busy with other work.

> >
> >>       return 0;
> >> diff --git a/drivers/usb/usbip/vhci_sysfs.c
> >> b/drivers/usb/usbip/vhci_sysfs.c
> >> index be37aec250c2..e167b8a445ad 100644
> >> --- a/drivers/usb/usbip/vhci_sysfs.c
> >> +++ b/drivers/usb/usbip/vhci_sysfs.c
> >> @@ -4,6 +4,7 @@
> >>    * Copyright (C) 2015-2016 Nobuo Iwata
> >>    */
> >> +#include <linux/kcov.h>
> >>   #include <linux/kthread.h>
> >>   #include <linux/file.h>
> >>   #include <linux/net.h>
> >> @@ -383,6 +384,9 @@ 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;
> >> +#ifdef CONFIG_KCOV
> >> +    vdev->ud.kcov_handle = kcov_common_handle();
> >> +#endif
> >
> >
> > Same here add a usbip_kcov_handle_init(ud)
> >
>
> btw - I am seeing bounces on handeharputlu@google.com address.

Hande is no longer at Google, so the email is no longer valid. I think
it makes sense to preserve the original email address in the patch.