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(I'm so sorry!) Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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C
123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119/* SPDX-License-Identifier: GPL-2.0 *//* * descriptor table internals; you almost certainly want file.h instead. */
#ifndef __LINUX_FDTABLE_H#define __LINUX_FDTABLE_H
#include <linux/posix_types.h>#include <linux/compiler.h>#include <linux/spinlock.h>#include <linux/rcupdate.h>#include <linux/nospec.h>#include <linux/types.h>#include <linux/init.h>#include <linux/fs.h>
#include <linux/atomic.h>
/* * The default fd array needs to be at least BITS_PER_LONG, * as this is the granularity returned by copy_fdset(). */#define NR_OPEN_DEFAULT BITS_PER_LONG
struct fdtable { unsigned int max_fds; struct file __rcu **fd; /* current fd array */ unsigned long *close_on_exec; unsigned long *open_fds; unsigned long *full_fds_bits; struct rcu_head rcu;};
/* * Open file table structure */struct files_struct { /* * read mostly part */ atomic_t count; bool resize_in_progress; wait_queue_head_t resize_wait;
struct fdtable __rcu *fdt; struct fdtable fdtab; /* * written part on a separate cache line in SMP */ spinlock_t file_lock ____cacheline_aligned_in_smp; unsigned int next_fd; unsigned long close_on_exec_init[1]; unsigned long open_fds_init[1]; unsigned long full_fds_bits_init[1]; struct file __rcu * fd_array[NR_OPEN_DEFAULT];};
struct file_operations;struct vfsmount;struct dentry;
#define rcu_dereference_check_fdtable(files, fdtfd) \ rcu_dereference_check((fdtfd), lockdep_is_held(&(files)->file_lock))
#define files_fdtable(files) \ rcu_dereference_check_fdtable((files), (files)->fdt)
/* * The caller must ensure that fd table isn't shared or hold rcu or file lock */static inline struct file *files_lookup_fd_raw(struct files_struct *files, unsigned int fd){ struct fdtable *fdt = rcu_dereference_raw(files->fdt); unsigned long mask = array_index_mask_nospec(fd, fdt->max_fds); struct file *needs_masking;
/* * 'mask' is zero for an out-of-bounds fd, all ones for ok. * 'fd&mask' is 'fd' for ok, or 0 for out of bounds. * * Accessing fdt->fd[0] is ok, but needs masking of the result. */ needs_masking = rcu_dereference_raw(fdt->fd[fd&mask]); return (struct file *)(mask & (unsigned long)needs_masking);}
static inline struct file *files_lookup_fd_locked(struct files_struct *files, unsigned int fd){ RCU_LOCKDEP_WARN(!lockdep_is_held(&files->file_lock), "suspicious rcu_dereference_check() usage"); return files_lookup_fd_raw(files, fd);}
static inline bool close_on_exec(unsigned int fd, const struct files_struct *files){ return test_bit(fd, files_fdtable(files)->close_on_exec);}
struct task_struct;
void put_files_struct(struct files_struct *fs);int unshare_files(void);struct fd_range { unsigned int from, to;};struct files_struct *dup_fd(struct files_struct *, struct fd_range *) __latent_entropy;void do_close_on_exec(struct files_struct *);int iterate_fd(struct files_struct *, unsigned, int (*)(const void *, struct file *, unsigned), const void *);
extern int close_fd(unsigned int fd);extern struct file *file_close_fd(unsigned int fd);
extern struct kmem_cache *files_cachep;
#endif /* __LINUX_FDTABLE_H */