vhost, kcov: collect coverage from vhost_worker (8f6a7f96) · Commits · 戴 / test

Add kcov_remote_start()/kcov_remote_stop() annotations to the vhost_worker() function, which is responsible for processing vhost works. Since vhost_worker() threads are spawned per vhost 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 vhost worker threads. Link: http://lkml.kernel.org/r/e49d5d154e5da6c9ada521d2b7ce10a49ce9f98b.1572366574.git.andreyknvl@google.com Signed-off-by:

Andrey Konovalov <andreyknvl@google.com> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Alexander Potapenko <glider@google.com> Cc: Anders Roxell <anders.roxell@linaro.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: David Windsor <dwindsor@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Elena Reshetova <elena.reshetova@intel.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jason Wang <jasowang@redhat.com> Cc: Marco Elver <elver@google.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by:

Andrew Morton <akpm@linux-foundation.org> Signed-off-by:

Linus Torvalds <torvalds@linux-foundation.org>

drivers/vhost/vhost.c

+6 −0

Original line number	Diff line number	Diff line
		@@ -30,6 +30,7 @@
		#include <linux/sched/signal.h>
		#include <linux/interval_tree_generic.h>
		#include <linux/nospec.h>
		#include <linux/kcov.h>

		#include "vhost.h"

		@@ -357,7 +358,9 @@ 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);
		kcov_remote_start_common(dev->kcov_handle);
		work->fn(work);
		kcov_remote_stop();
		if (need_resched())
		schedule();
		}
		@@ -546,6 +549,7 @@ long vhost_dev_set_owner(struct vhost_dev *dev)

		/* No owner, become one */
		dev->mm = get_task_mm(current);
		dev->kcov_handle = kcov_common_handle();
		worker = kthread_create(vhost_worker, dev, "vhost-%d", current->pid);
		if (IS_ERR(worker)) {
		err = PTR_ERR(worker);
		@@ -571,6 +575,7 @@ err_worker:
		if (dev->mm)
		mmput(dev->mm);
		dev->mm = NULL;
		dev->kcov_handle = 0;
		err_mm:
		return err;
		}
		@@ -682,6 +687,7 @@ void vhost_dev_cleanup(struct vhost_dev *dev)
		if (dev->worker) {
		kthread_stop(dev->worker);
		dev->worker = NULL;
		dev->kcov_handle = 0;
		}
		if (dev->mm)
		mmput(dev->mm);

drivers/vhost/vhost.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -173,6 +173,7 @@ struct vhost_dev {
		int iov_limit;
		int weight;
		int byte_weight;
		u64 kcov_handle;
		};

		bool vhost_exceeds_weight(struct vhost_virtqueue *vq, int pkts, int total_len);

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