From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Morton Subject: [patch 007/127] usb: core: kcov: collect coverage from usb complete callback Date: Thu, 04 Jun 2020 16:46:08 -0700 Message-ID: <20200604234608.8fH2tW1N9%akpm@linux-foundation.org> References: <20200604164523.e15f3177f4b69dcb4f2534a1@linux-foundation.org> Reply-To: linux-kernel@vger.kernel.org Return-path: Received: from mail.kernel.org ([198.145.29.99]:41132 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725863AbgFDXqK (ORCPT ); Thu, 4 Jun 2020 19:46:10 -0400 In-Reply-To: <20200604164523.e15f3177f4b69dcb4f2534a1@linux-foundation.org> Sender: mm-commits-owner@vger.kernel.org List-Id: mm-commits@vger.kernel.org To: akpm@linux-foundation.org, andreyknvl@gmail.com, andreyknvl@google.com, dvyukov@google.com, elver@google.com, glider@google.com, gregkh@linuxfoundation.org, linux-mm@kvack.org, mm-commits@vger.kernel.org, stern@rowland.harvard.edu, torvalds@linux-foundation.org From: Andrey Konovalov 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 Reviewed-by: Dmitry Vyukov Cc: Alan Stern Cc: Alexander Potapenko Cc: Andrey Konovalov Cc: Greg Kroah-Hartman Cc: Marco Elver Signed-off-by: Andrew Morton --- drivers/usb/core/hcd.c | 3 +++ 1 file changed, 3 insertions(+) --- 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 #include #include +#include #include #include @@ -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); _