135 lines
3.6 KiB
C
135 lines
3.6 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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/*
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* Wrapper functions for accessing the file_struct fd array.
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*/
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#ifndef __LINUX_FILE_H
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#define __LINUX_FILE_H
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#include <linux/compiler.h>
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#include <linux/types.h>
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#include <linux/posix_types.h>
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#include <linux/errno.h>
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#include <linux/cleanup.h>
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#include <linux/err.h>
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struct file;
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extern void fput(struct file *);
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struct file_operations;
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struct task_struct;
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struct vfsmount;
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struct dentry;
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struct inode;
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struct path;
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extern struct file *alloc_file_pseudo(struct inode *, struct vfsmount *,
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const char *, int flags, const struct file_operations *);
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extern struct file *alloc_file_pseudo_noaccount(struct inode *, struct vfsmount *,
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const char *, int flags, const struct file_operations *);
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extern struct file *alloc_file_clone(struct file *, int flags,
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const struct file_operations *);
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static inline void fput_light(struct file *file, int fput_needed)
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{
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if (fput_needed)
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fput(file);
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}
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/* either a reference to struct file + flags
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* (cloned vs. borrowed, pos locked), with
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* flags stored in lower bits of value,
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* or empty (represented by 0).
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*/
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struct fd {
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unsigned long word;
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};
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#define FDPUT_FPUT 1
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#define FDPUT_POS_UNLOCK 2
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#define fd_file(f) ((struct file *)((f).word & ~(FDPUT_FPUT|FDPUT_POS_UNLOCK)))
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static inline bool fd_empty(struct fd f)
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{
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return unlikely(!f.word);
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}
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#define EMPTY_FD (struct fd){0}
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static inline struct fd BORROWED_FD(struct file *f)
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{
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return (struct fd){(unsigned long)f};
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}
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static inline struct fd CLONED_FD(struct file *f)
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{
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return (struct fd){(unsigned long)f | FDPUT_FPUT};
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}
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static inline void fdput(struct fd fd)
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{
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if (fd.word & FDPUT_FPUT)
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fput(fd_file(fd));
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}
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extern struct file *fget(unsigned int fd);
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extern struct file *fget_raw(unsigned int fd);
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extern struct file *fget_task(struct task_struct *task, unsigned int fd);
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extern void __f_unlock_pos(struct file *);
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struct fd fdget(unsigned int fd);
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struct fd fdget_raw(unsigned int fd);
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struct fd fdget_pos(unsigned int fd);
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static inline void fdput_pos(struct fd f)
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{
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if (f.word & FDPUT_POS_UNLOCK)
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__f_unlock_pos(fd_file(f));
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fdput(f);
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}
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DEFINE_CLASS(fd, struct fd, fdput(_T), fdget(fd), int fd)
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DEFINE_CLASS(fd_raw, struct fd, fdput(_T), fdget_raw(fd), int fd)
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extern int f_dupfd(unsigned int from, struct file *file, unsigned flags);
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extern int replace_fd(unsigned fd, struct file *file, unsigned flags);
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extern void set_close_on_exec(unsigned int fd, int flag);
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extern bool get_close_on_exec(unsigned int fd);
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extern int __get_unused_fd_flags(unsigned flags, unsigned long nofile);
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extern int get_unused_fd_flags(unsigned flags);
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extern void put_unused_fd(unsigned int fd);
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DEFINE_CLASS(get_unused_fd, int, if (_T >= 0) put_unused_fd(_T),
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get_unused_fd_flags(flags), unsigned flags)
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DEFINE_FREE(fput, struct file *, if (!IS_ERR_OR_NULL(_T)) fput(_T))
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/*
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* take_fd() will take care to set @fd to -EBADF ensuring that
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* CLASS(get_unused_fd) won't call put_unused_fd(). This makes it
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* easier to rely on CLASS(get_unused_fd):
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*
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* struct file *f;
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*
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* CLASS(get_unused_fd, fd)(O_CLOEXEC);
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* if (fd < 0)
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* return fd;
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*
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* f = dentry_open(&path, O_RDONLY, current_cred());
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* if (IS_ERR(f))
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* return PTR_ERR(f);
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*
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* fd_install(fd, f);
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* return take_fd(fd);
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*/
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#define take_fd(fd) __get_and_null(fd, -EBADF)
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extern void fd_install(unsigned int fd, struct file *file);
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int receive_fd(struct file *file, int __user *ufd, unsigned int o_flags);
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int receive_fd_replace(int new_fd, struct file *file, unsigned int o_flags);
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extern void flush_delayed_fput(void);
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extern void __fput_sync(struct file *);
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extern unsigned int sysctl_nr_open_min, sysctl_nr_open_max;
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#endif /* __LINUX_FILE_H */
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