diff options
| -rw-r--r-- | Documentation/userspace-api/ioctl/ioctl-number.rst | 2 | ||||
| -rw-r--r-- | drivers/misc/ntsync.c | 131 | ||||
| -rw-r--r-- | include/uapi/linux/ntsync.h | 21 |
3 files changed, 154 insertions, 0 deletions
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 |