From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: Andrey Konovalov <andreyknvl@google.com>
Cc: linux-usb@vger.kernel.org, kvm@vger.kernel.org,
virtualization@lists.linux-foundation.org,
netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
Dmitry Vyukov <dvyukov@google.com>,
Alan Stern <stern@rowland.harvard.edu>,
"Michael S . Tsirkin" <mst@redhat.com>,
Jason Wang <jasowang@redhat.com>,
Andrew Morton <akpm@linux-foundation.org>,
Arnd Bergmann <arnd@arndb.de>,
Steven Rostedt <rostedt@goodmis.org>,
David Windsor <dwindsor@gmail.com>,
Elena Reshetova <elena.reshetova@intel.com>,
Anders Roxell <anders.roxell@linaro.org>
Subject: Re: [PATCH RFC 2/3] usb, kcov: collect coverage from hub_event
Date: Thu, 17 Oct 2019 11:19:43 -0700 [thread overview]
Message-ID: <20191017181943.GC1094415@kroah.com> (raw)
In-Reply-To: <1b30d1c9e7f86c25425c5ee53d7facede289608e.1571333592.git.andreyknvl@google.com>
On Thu, Oct 17, 2019 at 07:44:14PM +0200, Andrey Konovalov wrote:
> This patch adds kcov_remote_start/kcov_remote_stop annotations to the
> hub_event function, which is responsible for processing events on USB
> buses, in particular events that happen during USB device enumeration.
> Each USB bus gets a unique id, which can be used to attach a kcov device
> to a particular USB bus for coverage collection.
>
> Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
> ---
> drivers/usb/core/hub.c | 4 ++++
> include/linux/kcov.h | 1 +
> include/uapi/linux/kcov.h | 7 +++++++
> 3 files changed, 12 insertions(+)
>
> diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
> index 236313f41f4a..03a40e41b099 100644
> --- a/drivers/usb/core/hub.c
> +++ b/drivers/usb/core/hub.c
> @@ -5374,6 +5374,8 @@ static void hub_event(struct work_struct *work)
> hub_dev = hub->intfdev;
> intf = to_usb_interface(hub_dev);
>
> + kcov_remote_start(kcov_remote_handle_usb(hdev->bus->busnum));
> +
> dev_dbg(hub_dev, "state %d ports %d chg %04x evt %04x\n",
> hdev->state, hdev->maxchild,
> /* NOTE: expects max 15 ports... */
> @@ -5480,6 +5482,8 @@ static void hub_event(struct work_struct *work)
> /* Balance the stuff in kick_hub_wq() and allow autosuspend */
> usb_autopm_put_interface(intf);
> kref_put(&hub->kref, hub_release);
> +
> + kcov_remote_stop();
> }
>
> static const struct usb_device_id hub_id_table[] = {
> diff --git a/include/linux/kcov.h b/include/linux/kcov.h
> index 702672d98d35..38a47e0b67c2 100644
> --- a/include/linux/kcov.h
> +++ b/include/linux/kcov.h
> @@ -30,6 +30,7 @@ void kcov_task_exit(struct task_struct *t);
> /*
> * Reserved handle ranges:
> * 0000000000000000 - 0000ffffffffffff : common handles
> + * 0001000000000000 - 0001ffffffffffff : USB subsystem handles
So how many bits are you going to have for any in-kernel tasks? Aren't
you going to run out quickly?
> */
> void kcov_remote_start(u64 handle);
> void kcov_remote_stop(void);
> diff --git a/include/uapi/linux/kcov.h b/include/uapi/linux/kcov.h
> index 46f78f716ca9..45c9ae59cebc 100644
> --- a/include/uapi/linux/kcov.h
> +++ b/include/uapi/linux/kcov.h
> @@ -43,4 +43,11 @@ enum {
> #define KCOV_CMP_SIZE(n) ((n) << 1)
> #define KCOV_CMP_MASK KCOV_CMP_SIZE(3)
>
> +#define KCOV_REMOTE_HANDLE_USB 0x0001000000000000ull
> +
> +static inline __u64 kcov_remote_handle_usb(unsigned int bus)
> +{
> + return KCOV_REMOTE_HANDLE_USB + (__u64)bus;
> +}
Why is this function in a uapi .h file? What userspace code would call
this?
thanks,
greg k-h
next prev parent reply other threads:[~2019-10-17 18:19 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-17 17:44 [PATCH RFC 0/3] kcov: collect coverage from usb and vhost Andrey Konovalov
2019-10-17 17:44 ` [PATCH RFC 1/3] kcov: remote coverage support Andrey Konovalov
2019-10-21 13:53 ` Dmitry Vyukov
2019-10-22 16:44 ` Andrey Konovalov
2019-10-17 17:44 ` [PATCH RFC 2/3] usb, kcov: collect coverage from hub_event Andrey Konovalov
2019-10-17 18:19 ` Greg Kroah-Hartman [this message]
2019-10-17 19:06 ` Andrey Konovalov
2019-10-17 20:29 ` Greg Kroah-Hartman
2019-10-17 17:44 ` [PATCH RFC 3/3] vhost, kcov: collect coverage from vhost_worker Andrey Konovalov
2019-10-17 18:18 ` Greg Kroah-Hartman
2019-10-17 19:00 ` Andrey Konovalov
2019-10-17 20:28 ` Greg Kroah-Hartman
2019-10-17 20:29 ` Andrey Konovalov
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20191017181943.GC1094415@kroah.com \
--to=gregkh@linuxfoundation.org \
--cc=akpm@linux-foundation.org \
--cc=anders.roxell@linaro.org \
--cc=andreyknvl@google.com \
--cc=arnd@arndb.de \
--cc=dvyukov@google.com \
--cc=dwindsor@gmail.com \
--cc=elena.reshetova@intel.com \
--cc=jasowang@redhat.com \
--cc=kvm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-usb@vger.kernel.org \
--cc=mst@redhat.com \
--cc=netdev@vger.kernel.org \
--cc=rostedt@goodmis.org \
--cc=stern@rowland.harvard.edu \
--cc=virtualization@lists.linux-foundation.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).