From: Elizabeth Figura <zfigura@codeweavers.com>
To: Arnd Bergmann <arnd@arndb.de>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Jonathan Corbet <corbet@lwn.net>, Shuah Khan <shuah@kernel.org>
Cc: linux-kernel@vger.kernel.org, linux-api@vger.kernel.org,
wine-devel@winehq.org, "André Almeida" <andrealmeid@igalia.com>,
"Wolfram Sang" <wsa@kernel.org>,
"Arkadiusz Hiler" <ahiler@codeweavers.com>,
"Peter Zijlstra" <peterz@infradead.org>,
"Andy Lutomirski" <luto@kernel.org>,
linux-doc@vger.kernel.org, linux-kselftest@vger.kernel.org,
"Randy Dunlap" <rdunlap@infradead.org>,
"Elizabeth Figura" <zfigura@codeweavers.com>
Subject: [PATCH v3 02/30] ntsync: Introduce NTSYNC_IOC_CREATE_SEM.
Date: Thu, 28 Mar 2024 19:05:53 -0500 [thread overview]
Message-ID: <20240329000621.148791-3-zfigura@codeweavers.com> (raw)
In-Reply-To: <20240329000621.148791-1-zfigura@codeweavers.com>
This corresponds to the NT syscall NtCreateSemaphore().
Semaphores are one of three types of object to be implemented in this driver,
the others being mutexes and events.
An NT semaphore contains a 32-bit counter, and is signaled and can be acquired
when the counter is nonzero. The counter has a maximum value which is specified
at creation time. The initial value of the semaphore is also specified at
creation time. There are no restrictions on the maximum and initial value.
Each object is exposed as an file, to which any number of fds may be opened.
When all fds are closed, the object is deleted.
Objects hold a pointer to the ntsync_device that created them. The device's
reference count is driven by struct file.
Signed-off-by: Elizabeth Figura <zfigura@codeweavers.com>
---
.../userspace-api/ioctl/ioctl-number.rst | 2 +
drivers/misc/ntsync.c | 131 ++++++++++++++++++
include/uapi/linux/ntsync.h | 21 +++
3 files changed, 154 insertions(+)
create mode 100644 include/uapi/linux/ntsync.h
diff --git a/Documentation/userspace-api/ioctl/ioctl-number.rst b/Documentation/userspace-api/ioctl/ioctl-number.rst
index c472423412bf..a141e8e65c5d 100644
--- a/Documentation/userspace-api/ioctl/ioctl-number.rst
+++ b/Documentation/userspace-api/ioctl/ioctl-number.rst
@@ -174,6 +174,8 @@ Code Seq# Include File Comments
'M' 00-0F drivers/video/fsl-diu-fb.h conflict!
'N' 00-1F drivers/usb/scanner.h
'N' 40-7F drivers/block/nvme.c
+'N' 80-8F uapi/linux/ntsync.h NT synchronization primitives
+ <mailto:wine-devel@winehq.org>
'O' 00-06 mtd/ubi-user.h UBI
'P' all linux/soundcard.h conflict!
'P' 60-6F sound/sscape_ioctl.h conflict!
diff --git a/drivers/misc/ntsync.c b/drivers/misc/ntsync.c
index bd76e653d83e..20158ec148bc 100644
--- a/drivers/misc/ntsync.c
+++ b/drivers/misc/ntsync.c
@@ -5,26 +5,157 @@
* Copyright (C) 2024 Elizabeth Figura <zfigura@codeweavers.com>
*/
+#include <linux/anon_inodes.h>
+#include <linux/file.h>
#include <linux/fs.h>
#include <linux/miscdevice.h>
#include <linux/module.h>
+#include <linux/slab.h>
+#include <uapi/linux/ntsync.h>
#define NTSYNC_NAME "ntsync"
+enum ntsync_type {
+ NTSYNC_TYPE_SEM,
+};
+
+/*
+ * Individual synchronization primitives are represented by
+ * struct ntsync_obj, and each primitive is backed by a file.
+ *
+ * The whole namespace is represented by a struct ntsync_device also
+ * backed by a file.
+ *
+ * Both rely on struct file for reference counting. Individual
+ * ntsync_obj objects take a reference to the device when created.
+ */
+
+struct ntsync_obj {
+ enum ntsync_type type;
+
+ union {
+ struct {
+ __u32 count;
+ __u32 max;
+ } sem;
+ } u;
+
+ struct file *file;
+ struct ntsync_device *dev;
+};
+
+struct ntsync_device {
+ struct file *file;
+};
+
+static int ntsync_obj_release(struct inode *inode, struct file *file)
+{
+ struct ntsync_obj *obj = file->private_data;
+
+ fput(obj->dev->file);
+ kfree(obj);
+
+ return 0;
+}
+
+static const struct file_operations ntsync_obj_fops = {
+ .owner = THIS_MODULE,
+ .release = ntsync_obj_release,
+ .llseek = no_llseek,
+};
+
+static struct ntsync_obj *ntsync_alloc_obj(struct ntsync_device *dev,
+ enum ntsync_type type)
+{
+ struct ntsync_obj *obj;
+
+ obj = kzalloc(sizeof(*obj), GFP_KERNEL);
+ if (!obj)
+ return NULL;
+ obj->type = type;
+ obj->dev = dev;
+ get_file(dev->file);
+
+ return obj;
+}
+
+static int ntsync_obj_get_fd(struct ntsync_obj *obj)
+{
+ struct file *file;
+ int fd;
+
+ fd = get_unused_fd_flags(O_CLOEXEC);
+ if (fd < 0)
+ return fd;
+ file = anon_inode_getfile("ntsync", &ntsync_obj_fops, obj, O_RDWR);
+ if (IS_ERR(file)) {
+ put_unused_fd(fd);
+ return PTR_ERR(file);
+ }
+ obj->file = file;
+ fd_install(fd, file);
+
+ return fd;
+}
+
+static int ntsync_create_sem(struct ntsync_device *dev, void __user *argp)
+{
+ struct ntsync_sem_args __user *user_args = argp;
+ struct ntsync_sem_args args;
+ struct ntsync_obj *sem;
+ int fd;
+
+ if (copy_from_user(&args, argp, sizeof(args)))
+ return -EFAULT;
+
+ if (args.count > args.max)
+ return -EINVAL;
+
+ sem = ntsync_alloc_obj(dev, NTSYNC_TYPE_SEM);
+ if (!sem)
+ return -ENOMEM;
+ sem->u.sem.count = args.count;
+ sem->u.sem.max = args.max;
+ fd = ntsync_obj_get_fd(sem);
+ if (fd < 0) {
+ kfree(sem);
+ return fd;
+ }
+
+ return put_user(fd, &user_args->sem);
+}
+
static int ntsync_char_open(struct inode *inode, struct file *file)
{
+ struct ntsync_device *dev;
+
+ dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+ if (!dev)
+ return -ENOMEM;
+
+ file->private_data = dev;
+ dev->file = file;
return nonseekable_open(inode, file);
}
static int ntsync_char_release(struct inode *inode, struct file *file)
{
+ struct ntsync_device *dev = file->private_data;
+
+ kfree(dev);
+
return 0;
}
static long ntsync_char_ioctl(struct file *file, unsigned int cmd,
unsigned long parm)
{
+ struct ntsync_device *dev = file->private_data;
+ void __user *argp = (void __user *)parm;
+
switch (cmd) {
+ case NTSYNC_IOC_CREATE_SEM:
+ return ntsync_create_sem(dev, argp);
default:
return -ENOIOCTLCMD;
}
diff --git a/include/uapi/linux/ntsync.h b/include/uapi/linux/ntsync.h
new file mode 100644
index 000000000000..6a4867a6c97b
--- /dev/null
+++ b/include/uapi/linux/ntsync.h
@@ -0,0 +1,21 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+/*
+ * Kernel support for NT synchronization primitive emulation
+ *
+ * Copyright (C) 2021-2022 Elizabeth Figura <zfigura@codeweavers.com>
+ */
+
+#ifndef __LINUX_NTSYNC_H
+#define __LINUX_NTSYNC_H
+
+#include <linux/types.h>
+
+struct ntsync_sem_args {
+ __u32 sem;
+ __u32 count;
+ __u32 max;
+};
+
+#define NTSYNC_IOC_CREATE_SEM _IOWR('N', 0x80, struct ntsync_sem_args)
+
+#endif
--
2.43.0
next prev parent reply other threads:[~2024-03-29 0:24 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-03-29 0:05 [PATCH v3 00/30] NT synchronization primitive driver Elizabeth Figura
2024-03-29 0:05 ` [PATCH v3 01/30] ntsync: Introduce the ntsync driver and character device Elizabeth Figura
2024-03-29 0:05 ` Elizabeth Figura [this message]
2024-03-29 0:05 ` [PATCH v3 03/30] ntsync: Introduce NTSYNC_IOC_SEM_POST Elizabeth Figura
2024-04-11 13:35 ` Greg Kroah-Hartman
2024-03-29 0:05 ` [PATCH v3 04/30] ntsync: Introduce NTSYNC_IOC_WAIT_ANY Elizabeth Figura
2024-04-11 13:34 ` Greg Kroah-Hartman
2024-04-12 0:33 ` Elizabeth Figura
2024-04-12 6:16 ` Greg Kroah-Hartman
2024-03-29 0:05 ` [PATCH v3 05/30] ntsync: Introduce NTSYNC_IOC_WAIT_ALL Elizabeth Figura
2024-03-29 0:05 ` [PATCH v3 06/30] ntsync: Introduce NTSYNC_IOC_CREATE_MUTEX Elizabeth Figura
2024-03-29 0:05 ` [PATCH v3 07/30] ntsync: Introduce NTSYNC_IOC_MUTEX_UNLOCK Elizabeth Figura
2024-03-29 0:05 ` [PATCH v3 08/30] ntsync: Introduce NTSYNC_IOC_MUTEX_KILL Elizabeth Figura
2024-03-29 0:06 ` [PATCH v3 09/30] ntsync: Introduce NTSYNC_IOC_CREATE_EVENT Elizabeth Figura
2024-03-29 0:06 ` [PATCH v3 10/30] ntsync: Introduce NTSYNC_IOC_EVENT_SET Elizabeth Figura
2024-03-29 0:06 ` [PATCH v3 11/30] ntsync: Introduce NTSYNC_IOC_EVENT_RESET Elizabeth Figura
2024-03-29 0:06 ` [PATCH v3 12/30] ntsync: Introduce NTSYNC_IOC_EVENT_PULSE Elizabeth Figura
2024-03-29 0:06 ` [PATCH v3 13/30] ntsync: Introduce NTSYNC_IOC_SEM_READ Elizabeth Figura
2024-03-29 0:06 ` [PATCH v3 14/30] ntsync: Introduce NTSYNC_IOC_MUTEX_READ Elizabeth Figura
2024-03-29 0:06 ` [PATCH v3 15/30] ntsync: Introduce NTSYNC_IOC_EVENT_READ Elizabeth Figura
2024-03-29 0:06 ` [PATCH v3 16/30] ntsync: Introduce alertable waits Elizabeth Figura
2024-03-29 0:06 ` [PATCH v3 17/30] selftests: ntsync: Add some tests for semaphore state Elizabeth Figura
2024-03-29 20:07 ` Muhammad Usama Anjum
2024-03-29 0:06 ` [PATCH v3 18/30] selftests: ntsync: Add some tests for mutex state Elizabeth Figura
2024-03-29 0:06 ` [PATCH v3 19/30] selftests: ntsync: Add some tests for NTSYNC_IOC_WAIT_ANY Elizabeth Figura
2024-03-29 0:06 ` [PATCH v3 20/30] selftests: ntsync: Add some tests for NTSYNC_IOC_WAIT_ALL Elizabeth Figura
2024-03-29 0:06 ` [PATCH v3 21/30] selftests: ntsync: Add some tests for wakeup signaling with WINESYNC_IOC_WAIT_ANY Elizabeth Figura
2024-03-29 0:06 ` [PATCH v3 22/30] selftests: ntsync: Add some tests for wakeup signaling with WINESYNC_IOC_WAIT_ALL Elizabeth Figura
2024-03-29 0:06 ` [PATCH v3 23/30] selftests: ntsync: Add some tests for manual-reset event state Elizabeth Figura
2024-03-29 0:06 ` [PATCH v3 24/30] selftests: ntsync: Add some tests for auto-reset " Elizabeth Figura
2024-03-29 0:06 ` [PATCH v3 25/30] selftests: ntsync: Add some tests for wakeup signaling with events Elizabeth Figura
2024-03-29 0:06 ` [PATCH v3 26/30] selftests: ntsync: Add tests for alertable waits Elizabeth Figura
2024-03-29 0:06 ` [PATCH v3 27/30] selftests: ntsync: Add some tests for wakeup signaling via alerts Elizabeth Figura
2024-03-29 0:06 ` [PATCH v3 28/30] selftests: ntsync: Add a stress test for contended waits Elizabeth Figura
2024-03-29 0:06 ` [PATCH v3 29/30] maintainers: Add an entry for ntsync Elizabeth Figura
2024-03-29 0:06 ` [PATCH v3 30/30] docs: ntsync: Add documentation for the ntsync uAPI Elizabeth Figura
2024-04-12 5:52 ` Bagas Sanjaya
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