linux-kernel - [char-misc-next 7/9] mei: support polling for event notification

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Wed, 24 Jun 2015 11:59:29 +0300
From:	Tomas Winkler <tomas.winkler@...el.com>
To:	gregkh@...uxfoundation.org
Cc:	arnd@...db.de, linux-kernel@...r.kernel.org,
	Tomas Winkler <tomas.winkler@...el.com>,
	Alexander Usyskin <alexander.usyskin@...el.com>
Subject: [char-misc-next 7/9] mei: support polling for event notification

Polling on priority events is translated on waiting for event
notification. One need to enable notification prior for
calling select or poll system call otherwise process
will not wait.

Signed-off-by: Tomas Winkler <tomas.winkler@...el.com>
Signed-off-by: Alexander Usyskin <alexander.usyskin@...el.com>
---
 drivers/misc/mei/main.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/misc/mei/main.c b/drivers/misc/mei/main.c
index 4a3f72986ecb..79892a480de5 100644
--- a/drivers/misc/mei/main.c
+++ b/drivers/misc/mei/main.c
@@ -607,6 +607,7 @@ static unsigned int mei_poll(struct file *file, poll_table *wait)
 	struct mei_cl *cl = file->private_data;
 	struct mei_device *dev;
 	unsigned int mask = 0;
+	bool notify_en;
 
 	if (WARN_ON(!cl || !cl->dev))
 		return POLLERR;
@@ -615,6 +616,7 @@ static unsigned int mei_poll(struct file *file, poll_table *wait)
 
 	mutex_lock(&dev->device_lock);
 
+	notify_en = cl->notify_en && (req_events & POLLPRI);
 
 	if (dev->dev_state != MEI_DEV_ENABLED ||
 	    !mei_cl_is_connected(cl)) {
@@ -627,6 +629,12 @@ static unsigned int mei_poll(struct file *file, poll_table *wait)
 		goto out;
 	}
 
+	if (notify_en) {
+		poll_wait(file, &cl->ev_wait, wait);
+		if (cl->notify_ev)
+			mask |= POLLPRI;
+	}
+
 	if (req_events & (POLLIN | POLLRDNORM)) {
 		poll_wait(file, &cl->rx_wait, wait);
 
-- 
2.4.3

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/