linux-kernel - [PATCH 12/31] ntsync: Introduce NTSYNC_IOC_EVENT

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]

Message-ID: <20240214235307.10494-3-zfigura@codeweavers.com>
Date: Wed, 14 Feb 2024 17:52:47 -0600
From: Elizabeth Figura <zfigura@...eweavers.com>
To: Arnd Bergmann <arnd@...db.de>,
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	Jonathan Corbet <corbet@....net>,
	Shuah Khan <shuah@...nel.org>
Cc: linux-kernel@...r.kernel.org,
	linux-api@...r.kernel.org,
	wine-devel@...ehq.org,
	André Almeida <andrealmeid@...lia.com>,
	Wolfram Sang <wsa@...nel.org>,
	Arkadiusz Hiler <ahiler@...eweavers.com>,
	Peter Zijlstra <peterz@...radead.org>,
	Andy Lutomirski <luto@...nel.org>,
	linux-doc@...r.kernel.org,
	linux-kselftest@...r.kernel.org,
	Elizabeth Figura <zfigura@...eweavers.com>
Subject: [PATCH 12/31] ntsync: Introduce NTSYNC_IOC_EVENT_PULSE.

This corresponds to the NT syscall NtPulseEvent().

This wakes up any waiters as if the event had been set, but does not set the
event, instead resetting it if it had been signalled. Thus, for a manual-reset
event, all waiters are woken, whereas for an auto-reset event, at most one
waiter is woken.

Signed-off-by: Elizabeth Figura <zfigura@...eweavers.com>
---
 drivers/misc/ntsync.c       | 10 ++++++++--
 include/uapi/linux/ntsync.h |  1 +
 2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/drivers/misc/ntsync.c b/drivers/misc/ntsync.c
index 57d78b086241..e8e58274e4e8 100644
--- a/drivers/misc/ntsync.c
+++ b/drivers/misc/ntsync.c
@@ -456,7 +456,7 @@ static int ntsync_mutex_kill(struct ntsync_obj *mutex, void __user *argp)
 	return ret;
 }
 
-static int ntsync_event_set(struct ntsync_obj *event, void __user *argp)
+static int ntsync_event_set(struct ntsync_obj *event, void __user *argp, bool pulse)
 {
 	struct ntsync_device *dev = event->dev;
 	__u32 prev_state;
@@ -472,6 +472,8 @@ static int ntsync_event_set(struct ntsync_obj *event, void __user *argp)
 		event->u.event.signaled = true;
 		try_wake_all_obj(dev, event);
 		try_wake_any_event(event);
+		if (pulse)
+			event->u.event.signaled = false;
 
 		spin_unlock(&event->lock);
 		spin_unlock(&dev->wait_all_lock);
@@ -481,6 +483,8 @@ static int ntsync_event_set(struct ntsync_obj *event, void __user *argp)
 		prev_state = event->u.event.signaled;
 		event->u.event.signaled = true;
 		try_wake_any_event(event);
+		if (pulse)
+			event->u.event.signaled = false;
 
 		spin_unlock(&event->lock);
 	}
@@ -535,9 +539,11 @@ static long ntsync_obj_ioctl(struct file *file, unsigned int cmd,
 	case NTSYNC_IOC_MUTEX_KILL:
 		return ntsync_mutex_kill(obj, argp);
 	case NTSYNC_IOC_EVENT_SET:
-		return ntsync_event_set(obj, argp);
+		return ntsync_event_set(obj, argp, false);
 	case NTSYNC_IOC_EVENT_RESET:
 		return ntsync_event_reset(obj, argp);
+	case NTSYNC_IOC_EVENT_PULSE:
+		return ntsync_event_set(obj, argp, true);
 	default:
 		return -ENOIOCTLCMD;
 	}
diff --git a/include/uapi/linux/ntsync.h b/include/uapi/linux/ntsync.h
index f2d7507d8438..598f894f868d 100644
--- a/include/uapi/linux/ntsync.h
+++ b/include/uapi/linux/ntsync.h
@@ -50,5 +50,6 @@ struct ntsync_wait_args {
 #define NTSYNC_IOC_MUTEX_KILL		_IOW ('N', 0x86, __u32)
 #define NTSYNC_IOC_EVENT_SET		_IOR ('N', 0x88, __u32)
 #define NTSYNC_IOC_EVENT_RESET		_IOR ('N', 0x89, __u32)
+#define NTSYNC_IOC_EVENT_PULSE		_IOR ('N', 0x8a, __u32)
 
 #endif
-- 
2.43.0