192 lines
4.2 KiB
Diff
192 lines
4.2 KiB
Diff
These correspond to the NT syscalls NtCreateSemaphore() and NtClose().
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Unlike those functions, however, these ioctls do not handle object names, or
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lookup of existing objects, or handle reference counting, but simply create the
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underlying primitive. The user space emulator is expected to implement those
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functions if they are required.
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Signed-off-by: Elizabeth Figura <zfigura@codeweavers.com>
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---
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drivers/misc/ntsync.c | 117 ++++++++++++++++++++++++++++++++++++
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include/uapi/linux/ntsync.h | 25 ++++++++
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2 files changed, 142 insertions(+)
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create mode 100644 include/uapi/linux/ntsync.h
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diff --git a/drivers/misc/ntsync.c b/drivers/misc/ntsync.c
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index 84b498e2b2d5..3287b94be351 100644
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--- a/drivers/misc/ntsync.c
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+++ b/drivers/misc/ntsync.c
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@@ -8,23 +8,140 @@
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#include <linux/fs.h>
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#include <linux/miscdevice.h>
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#include <linux/module.h>
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+#include <linux/slab.h>
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+#include <linux/xarray.h>
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+#include <uapi/linux/ntsync.h>
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#define NTSYNC_NAME "ntsync"
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+enum ntsync_type {
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+ NTSYNC_TYPE_SEM,
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+};
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+
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+struct ntsync_obj {
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+ struct rcu_head rhead;
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+ struct kref refcount;
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+
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+ enum ntsync_type type;
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+
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+ union {
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+ struct {
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+ __u32 count;
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+ __u32 max;
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+ } sem;
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+ } u;
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+};
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+
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+struct ntsync_device {
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+ struct xarray objects;
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+};
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+
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+static void destroy_obj(struct kref *ref)
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+{
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+ struct ntsync_obj *obj = container_of(ref, struct ntsync_obj, refcount);
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+
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+ kfree_rcu(obj, rhead);
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+}
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+
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+static void put_obj(struct ntsync_obj *obj)
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+{
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+ kref_put(&obj->refcount, destroy_obj);
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+}
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+
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static int ntsync_char_open(struct inode *inode, struct file *file)
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{
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+ struct ntsync_device *dev;
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+
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+ dev = kzalloc(sizeof(*dev), GFP_KERNEL);
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+ if (!dev)
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+ return -ENOMEM;
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+
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+ xa_init_flags(&dev->objects, XA_FLAGS_ALLOC);
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+
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+ file->private_data = dev;
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return nonseekable_open(inode, file);
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}
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static int ntsync_char_release(struct inode *inode, struct file *file)
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{
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+ struct ntsync_device *dev = file->private_data;
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+ struct ntsync_obj *obj;
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+ unsigned long id;
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+
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+ xa_for_each(&dev->objects, id, obj)
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+ put_obj(obj);
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+
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+ xa_destroy(&dev->objects);
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+
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+ kfree(dev);
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+
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+ return 0;
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+}
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+
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+static void init_obj(struct ntsync_obj *obj)
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+{
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+ kref_init(&obj->refcount);
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+}
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+
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+static int ntsync_create_sem(struct ntsync_device *dev, void __user *argp)
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+{
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+ struct ntsync_sem_args __user *user_args = argp;
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+ struct ntsync_sem_args args;
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+ struct ntsync_obj *sem;
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+ __u32 id;
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+ int ret;
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+
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+ if (copy_from_user(&args, argp, sizeof(args)))
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+ return -EFAULT;
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+
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+ if (args.count > args.max)
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+ return -EINVAL;
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+
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+ sem = kzalloc(sizeof(*sem), GFP_KERNEL);
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+ if (!sem)
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+ return -ENOMEM;
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+
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+ init_obj(sem);
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+ sem->type = NTSYNC_TYPE_SEM;
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+ sem->u.sem.count = args.count;
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+ sem->u.sem.max = args.max;
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+
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+ ret = xa_alloc(&dev->objects, &id, sem, xa_limit_32b, GFP_KERNEL);
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+ if (ret < 0) {
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+ kfree(sem);
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+ return ret;
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+ }
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+
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+ return put_user(id, &user_args->sem);
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+}
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+
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+static int ntsync_delete(struct ntsync_device *dev, void __user *argp)
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+{
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+ struct ntsync_obj *obj;
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+ __u32 id;
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+
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+ if (get_user(id, (__u32 __user *)argp))
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+ return -EFAULT;
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+
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+ obj = xa_erase(&dev->objects, id);
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+ if (!obj)
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+ return -EINVAL;
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+
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+ put_obj(obj);
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return 0;
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}
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static long ntsync_char_ioctl(struct file *file, unsigned int cmd,
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unsigned long parm)
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{
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+ struct ntsync_device *dev = file->private_data;
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+ void __user *argp = (void __user *)parm;
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+
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switch (cmd) {
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+ case NTSYNC_IOC_CREATE_SEM:
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+ return ntsync_create_sem(dev, argp);
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+ case NTSYNC_IOC_DELETE:
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+ return ntsync_delete(dev, argp);
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default:
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return -ENOIOCTLCMD;
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}
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diff --git a/include/uapi/linux/ntsync.h b/include/uapi/linux/ntsync.h
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new file mode 100644
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index 000000000000..d97afc138dcc
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--- /dev/null
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+++ b/include/uapi/linux/ntsync.h
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@@ -0,0 +1,25 @@
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+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
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+/*
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+ * Kernel support for NT synchronization primitive emulation
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+ *
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+ * Copyright (C) 2021-2022 Elizabeth Figura
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+ */
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+
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+#ifndef __LINUX_NTSYNC_H
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+#define __LINUX_NTSYNC_H
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+
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+#include <linux/types.h>
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+
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+struct ntsync_sem_args {
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+ __u32 sem;
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+ __u32 count;
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+ __u32 max;
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+};
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+
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+#define NTSYNC_IOC_BASE 0xf7
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+
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+#define NTSYNC_IOC_CREATE_SEM _IOWR(NTSYNC_IOC_BASE, 0, \
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+ struct ntsync_sem_args)
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+#define NTSYNC_IOC_DELETE _IOW (NTSYNC_IOC_BASE, 1, __u32)
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+
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+#endif
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--
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2.43.0
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