[157/166] usb: core: kcov: collect coverage from usb complete callback
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Message ID 20200407031224.aNxjirzI7%akpm@linux-foundation.org
State New
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Series
  • [001/166] mm, memcg: bypass high reclaim iteration for cgroup hierarchy root
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Commit Message

Andrew Morton April 7, 2020, 3:12 a.m. UTC
From: Andrey Konovalov <andreyknvl@google.com>
Subject: 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.

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

 drivers/usb/core/hcd.c |    3 +++
 1 file changed, 3 insertions(+)

Patch
diff mbox series

--- a/drivers/usb/core/hcd.c~usb-core-kcov-collect-coverage-from-usb-complete-callback
+++ a/drivers/usb/core/hcd.c
@@ -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(struc
 
 	/* 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);