Commit 76e278d6 authored Jun 04, 2020 by Andrey Konovalov Committed by Linus Torvalds Jun 04, 2020

usb: core: kcov: collect coverage from usb complete callback



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
callbacks, which is used to facilitate coverage-guided fuzzing with
syzkaller.

Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Marco Elver <elver@google.com>
Link: http://lkml.kernel.org/r/4520671eeb604adbc2432c248b0c07fbaa5519ef.1585233617.git.andreyknvl@google.com
Link: http://lkml.kernel.org/r/2821d497ac1cdc0efb5e00df30271e4a67fc8009.1584655448.git.andreyknvl@google.com


Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 5ff3b30a

drivers/usb/core/hcd.c

+3 −0

Original line number	Diff line number	Diff line
		@@ -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);

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