diff mbox series

[RFC,3/3] vhost, kcov: collect coverage from vhost_worker

Message ID af26317c0efd412dd660e81d548a173942f8a0ad.1571333592.git.andreyknvl@google.com (mailing list archive)
State Superseded
Headers show
Series kcov: collect coverage from usb and vhost | expand

Commit Message

Andrey Konovalov Oct. 17, 2019, 5:44 p.m. UTC
This patch adds kcov_remote_start/kcov_remote_stop annotations to the
vhost_worker function, which is responsible for processing vhost works.
Since vhost_worker is spawned when a vhost device instance is created,
the common kcov handle is used for kcov_remote_start/stop annotations.

Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
---
 drivers/vhost/vhost.c | 15 +++++++++++++++
 drivers/vhost/vhost.h |  3 +++
 2 files changed, 18 insertions(+)

Comments

Greg Kroah-Hartman Oct. 17, 2019, 6:18 p.m. UTC | #1
On Thu, Oct 17, 2019 at 07:44:15PM +0200, Andrey Konovalov wrote:
> This patch adds kcov_remote_start/kcov_remote_stop annotations to the
> vhost_worker function, which is responsible for processing vhost works.
> Since vhost_worker is spawned when a vhost device instance is created,
> the common kcov handle is used for kcov_remote_start/stop annotations.
> 
> Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
> ---
>  drivers/vhost/vhost.c | 15 +++++++++++++++
>  drivers/vhost/vhost.h |  3 +++
>  2 files changed, 18 insertions(+)
> 
> diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
> index 36ca2cf419bf..71a349f6b352 100644
> --- a/drivers/vhost/vhost.c
> +++ b/drivers/vhost/vhost.c
> @@ -357,7 +357,13 @@ static int vhost_worker(void *data)
>  		llist_for_each_entry_safe(work, work_next, node, node) {
>  			clear_bit(VHOST_WORK_QUEUED, &work->flags);
>  			__set_current_state(TASK_RUNNING);
> +#ifdef CONFIG_KCOV
> +			kcov_remote_start(dev->kcov_handle);
> +#endif

Shouldn't you hide these #ifdefs in a .h file?  This is not a "normal"
kernel coding style at all.

>  			work->fn(work);
> +#ifdef CONFIG_KCOV
> +			kcov_remote_stop();
> +#endif
>  			if (need_resched())
>  				schedule();
>  		}
> @@ -546,6 +552,9 @@ long vhost_dev_set_owner(struct vhost_dev *dev)
>  
>  	/* No owner, become one */
>  	dev->mm = get_task_mm(current);
> +#ifdef CONFIG_KCOV
> +	dev->kcov_handle = current->kcov_handle;
> +#endif
>  	worker = kthread_create(vhost_worker, dev, "vhost-%d", current->pid);
>  	if (IS_ERR(worker)) {
>  		err = PTR_ERR(worker);
> @@ -571,6 +580,9 @@ long vhost_dev_set_owner(struct vhost_dev *dev)
>  	if (dev->mm)
>  		mmput(dev->mm);
>  	dev->mm = NULL;
> +#ifdef CONFIG_KCOV
> +	dev->kcov_handle = 0;
> +#endif
>  err_mm:
>  	return err;
>  }
> @@ -682,6 +694,9 @@ void vhost_dev_cleanup(struct vhost_dev *dev)
>  	if (dev->worker) {
>  		kthread_stop(dev->worker);
>  		dev->worker = NULL;
> +#ifdef CONFIG_KCOV
> +		dev->kcov_handle = 0;
> +#endif
>  	}
>  	if (dev->mm)
>  		mmput(dev->mm);
> diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h
> index e9ed2722b633..010ca1ebcbd5 100644
> --- a/drivers/vhost/vhost.h
> +++ b/drivers/vhost/vhost.h
> @@ -173,6 +173,9 @@ struct vhost_dev {
>  	int iov_limit;
>  	int weight;
>  	int byte_weight;
> +#ifdef CONFIG_KCOV
> +	u64 kcov_handle;
> +#endif

Why is this a #ifdef at all here?

thanks,

greg k-h
Andrey Konovalov Oct. 17, 2019, 7 p.m. UTC | #2
On Thu, Oct 17, 2019 at 8:18 PM Greg Kroah-Hartman
<gregkh@linuxfoundation.org> wrote:
>
> On Thu, Oct 17, 2019 at 07:44:15PM +0200, Andrey Konovalov wrote:
> > This patch adds kcov_remote_start/kcov_remote_stop annotations to the
> > vhost_worker function, which is responsible for processing vhost works.
> > Since vhost_worker is spawned when a vhost device instance is created,
> > the common kcov handle is used for kcov_remote_start/stop annotations.
> >
> > Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
> > ---
> >  drivers/vhost/vhost.c | 15 +++++++++++++++
> >  drivers/vhost/vhost.h |  3 +++
> >  2 files changed, 18 insertions(+)
> >
> > diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
> > index 36ca2cf419bf..71a349f6b352 100644
> > --- a/drivers/vhost/vhost.c
> > +++ b/drivers/vhost/vhost.c
> > @@ -357,7 +357,13 @@ static int vhost_worker(void *data)
> >               llist_for_each_entry_safe(work, work_next, node, node) {
> >                       clear_bit(VHOST_WORK_QUEUED, &work->flags);
> >                       __set_current_state(TASK_RUNNING);
> > +#ifdef CONFIG_KCOV
> > +                     kcov_remote_start(dev->kcov_handle);
> > +#endif
>
> Shouldn't you hide these #ifdefs in a .h file?  This is not a "normal"
> kernel coding style at all.

Well, if it's acceptable to add a kcov_handle field into vhost_dev
even when CONFIG_KCOV is not enabled, then we can get rid of those
#ifdefs.

>
> >                       work->fn(work);
> > +#ifdef CONFIG_KCOV
> > +                     kcov_remote_stop();
> > +#endif
> >                       if (need_resched())
> >                               schedule();
> >               }
> > @@ -546,6 +552,9 @@ long vhost_dev_set_owner(struct vhost_dev *dev)
> >
> >       /* No owner, become one */
> >       dev->mm = get_task_mm(current);
> > +#ifdef CONFIG_KCOV
> > +     dev->kcov_handle = current->kcov_handle;
> > +#endif
> >       worker = kthread_create(vhost_worker, dev, "vhost-%d", current->pid);
> >       if (IS_ERR(worker)) {
> >               err = PTR_ERR(worker);
> > @@ -571,6 +580,9 @@ long vhost_dev_set_owner(struct vhost_dev *dev)
> >       if (dev->mm)
> >               mmput(dev->mm);
> >       dev->mm = NULL;
> > +#ifdef CONFIG_KCOV
> > +     dev->kcov_handle = 0;
> > +#endif
> >  err_mm:
> >       return err;
> >  }
> > @@ -682,6 +694,9 @@ void vhost_dev_cleanup(struct vhost_dev *dev)
> >       if (dev->worker) {
> >               kthread_stop(dev->worker);
> >               dev->worker = NULL;
> > +#ifdef CONFIG_KCOV
> > +             dev->kcov_handle = 0;
> > +#endif
> >       }
> >       if (dev->mm)
> >               mmput(dev->mm);
> > diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h
> > index e9ed2722b633..010ca1ebcbd5 100644
> > --- a/drivers/vhost/vhost.h
> > +++ b/drivers/vhost/vhost.h
> > @@ -173,6 +173,9 @@ struct vhost_dev {
> >       int iov_limit;
> >       int weight;
> >       int byte_weight;
> > +#ifdef CONFIG_KCOV
> > +     u64 kcov_handle;
> > +#endif
>
> Why is this a #ifdef at all here?
>
> thanks,
>
> greg k-h
Greg Kroah-Hartman Oct. 17, 2019, 8:28 p.m. UTC | #3
On Thu, Oct 17, 2019 at 09:00:18PM +0200, Andrey Konovalov wrote:
> On Thu, Oct 17, 2019 at 8:18 PM Greg Kroah-Hartman
> <gregkh@linuxfoundation.org> wrote:
> >
> > On Thu, Oct 17, 2019 at 07:44:15PM +0200, Andrey Konovalov wrote:
> > > This patch adds kcov_remote_start/kcov_remote_stop annotations to the
> > > vhost_worker function, which is responsible for processing vhost works.
> > > Since vhost_worker is spawned when a vhost device instance is created,
> > > the common kcov handle is used for kcov_remote_start/stop annotations.
> > >
> > > Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
> > > ---
> > >  drivers/vhost/vhost.c | 15 +++++++++++++++
> > >  drivers/vhost/vhost.h |  3 +++
> > >  2 files changed, 18 insertions(+)
> > >
> > > diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
> > > index 36ca2cf419bf..71a349f6b352 100644
> > > --- a/drivers/vhost/vhost.c
> > > +++ b/drivers/vhost/vhost.c
> > > @@ -357,7 +357,13 @@ static int vhost_worker(void *data)
> > >               llist_for_each_entry_safe(work, work_next, node, node) {
> > >                       clear_bit(VHOST_WORK_QUEUED, &work->flags);
> > >                       __set_current_state(TASK_RUNNING);
> > > +#ifdef CONFIG_KCOV
> > > +                     kcov_remote_start(dev->kcov_handle);
> > > +#endif
> >
> > Shouldn't you hide these #ifdefs in a .h file?  This is not a "normal"
> > kernel coding style at all.
> 
> Well, if it's acceptable to add a kcov_handle field into vhost_dev
> even when CONFIG_KCOV is not enabled, then we can get rid of those
> #ifdefs.

It should be, it's not a big deal and there's not a ton of those
structures around that one more field is going to hurt anything...

thanks,

greg k-h
Andrey Konovalov Oct. 17, 2019, 8:29 p.m. UTC | #4
On Thu, Oct 17, 2019 at 10:28 PM Greg Kroah-Hartman
<gregkh@linuxfoundation.org> wrote:
>
> On Thu, Oct 17, 2019 at 09:00:18PM +0200, Andrey Konovalov wrote:
> > On Thu, Oct 17, 2019 at 8:18 PM Greg Kroah-Hartman
> > <gregkh@linuxfoundation.org> wrote:
> > >
> > > On Thu, Oct 17, 2019 at 07:44:15PM +0200, Andrey Konovalov wrote:
> > > > This patch adds kcov_remote_start/kcov_remote_stop annotations to the
> > > > vhost_worker function, which is responsible for processing vhost works.
> > > > Since vhost_worker is spawned when a vhost device instance is created,
> > > > the common kcov handle is used for kcov_remote_start/stop annotations.
> > > >
> > > > Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
> > > > ---
> > > >  drivers/vhost/vhost.c | 15 +++++++++++++++
> > > >  drivers/vhost/vhost.h |  3 +++
> > > >  2 files changed, 18 insertions(+)
> > > >
> > > > diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
> > > > index 36ca2cf419bf..71a349f6b352 100644
> > > > --- a/drivers/vhost/vhost.c
> > > > +++ b/drivers/vhost/vhost.c
> > > > @@ -357,7 +357,13 @@ static int vhost_worker(void *data)
> > > >               llist_for_each_entry_safe(work, work_next, node, node) {
> > > >                       clear_bit(VHOST_WORK_QUEUED, &work->flags);
> > > >                       __set_current_state(TASK_RUNNING);
> > > > +#ifdef CONFIG_KCOV
> > > > +                     kcov_remote_start(dev->kcov_handle);
> > > > +#endif
> > >
> > > Shouldn't you hide these #ifdefs in a .h file?  This is not a "normal"
> > > kernel coding style at all.
> >
> > Well, if it's acceptable to add a kcov_handle field into vhost_dev
> > even when CONFIG_KCOV is not enabled, then we can get rid of those
> > #ifdefs.
>
> It should be, it's not a big deal and there's not a ton of those
> structures around that one more field is going to hurt anything...

OK, I'll do that in the next version then, thanks!
diff mbox series

Patch

diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index 36ca2cf419bf..71a349f6b352 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -357,7 +357,13 @@  static int vhost_worker(void *data)
 		llist_for_each_entry_safe(work, work_next, node, node) {
 			clear_bit(VHOST_WORK_QUEUED, &work->flags);
 			__set_current_state(TASK_RUNNING);
+#ifdef CONFIG_KCOV
+			kcov_remote_start(dev->kcov_handle);
+#endif
 			work->fn(work);
+#ifdef CONFIG_KCOV
+			kcov_remote_stop();
+#endif
 			if (need_resched())
 				schedule();
 		}
@@ -546,6 +552,9 @@  long vhost_dev_set_owner(struct vhost_dev *dev)
 
 	/* No owner, become one */
 	dev->mm = get_task_mm(current);
+#ifdef CONFIG_KCOV
+	dev->kcov_handle = current->kcov_handle;
+#endif
 	worker = kthread_create(vhost_worker, dev, "vhost-%d", current->pid);
 	if (IS_ERR(worker)) {
 		err = PTR_ERR(worker);
@@ -571,6 +580,9 @@  long vhost_dev_set_owner(struct vhost_dev *dev)
 	if (dev->mm)
 		mmput(dev->mm);
 	dev->mm = NULL;
+#ifdef CONFIG_KCOV
+	dev->kcov_handle = 0;
+#endif
 err_mm:
 	return err;
 }
@@ -682,6 +694,9 @@  void vhost_dev_cleanup(struct vhost_dev *dev)
 	if (dev->worker) {
 		kthread_stop(dev->worker);
 		dev->worker = NULL;
+#ifdef CONFIG_KCOV
+		dev->kcov_handle = 0;
+#endif
 	}
 	if (dev->mm)
 		mmput(dev->mm);
diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h
index e9ed2722b633..010ca1ebcbd5 100644
--- a/drivers/vhost/vhost.h
+++ b/drivers/vhost/vhost.h
@@ -173,6 +173,9 @@  struct vhost_dev {
 	int iov_limit;
 	int weight;
 	int byte_weight;
+#ifdef CONFIG_KCOV
+	u64 kcov_handle;
+#endif
 };
 
 bool vhost_exceeds_weight(struct vhost_virtqueue *vq, int pkts, int total_len);