include/wrapper/fdtable.h

   1 /* SPDX-License-Identifier: (GPL-2.0-only or LGPL-2.1-only)
   2  *
   3  * wrapper/fdtable.h
   4  *
   5  * Copyright (C) 2013 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   6  */
   7
   8 #ifndef _LTTNG_WRAPPER_FDTABLE_H
   9 #define _LTTNG_WRAPPER_FDTABLE_H
  10
  11 #include <lttng/kernel-version.h>
  12 #include <linux/fdtable.h>
  13 #include <linux/sched.h>
  14
  15 #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(6,7,0))
  16 static inline
  17 struct file *lttng_lookup_fdget_rcu(unsigned int fd)
  18 {
  19         return lookup_fdget_rcu(fd);
  20 }
  21
  22 #elif (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(5,11,0))
  23 static inline
  24 struct file *lttng_lookup_fdget_rcu(unsigned int fd)
  25 {
  26         struct file* file = lookup_fd_rcu(fd);
  27
  28         if (unlikely(!file || !get_file_rcu(file)))
  29                 return NULL;
  30         return file;
  31 }
  32 #elif (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,1,0))
  33 static inline
  34 struct file *lttng_lookup_fdget_rcu(unsigned int fd)
  35 {
  36         struct file* file = fcheck(fd);
  37
  38         if (unlikely(!file || !get_file_rcu(file)))
  39                 return NULL;
  40         return file;
  41 }
  42 #else
  43 static inline
  44 struct file *lttng_lookup_fdget_rcu(unsigned int fd)
  45 {
  46         struct file* file = fcheck(fd);
  47
  48         if (unlikely(!file || !atomic_long_inc_not_zero(&file->f_count)))
  49                 return NULL;
  50         return file;
  51 }
  52 #endif
  53
  54 #if (LTTNG_LINUX_VERSION_CODE < LTTNG_KERNEL_VERSION(3,7,0))
  55
  56 int lttng_iterate_fd(struct files_struct *files,
  57                 unsigned int first,
  58                 int (*cb)(const void *, struct file *, unsigned int),
  59                 const void *ctx);
  60
  61 #else
  62
  63 /*
  64  * iterate_fd() appeared at commit
  65  * c3c073f808b22dfae15ef8412b6f7b998644139a in the Linux kernel (first
  66  * released kernel: v3.7).
  67  */
  68 #define lttng_iterate_fd        iterate_fd
  69
  70 #endif
  71
  72 #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(3,4,0))
  73
  74 static inline bool lttng_close_on_exec(int fd, const struct fdtable *fdt)
  75 {
  76         return close_on_exec(fd, fdt);
  77 }
  78
  79 #else
  80
  81 static inline bool lttng_close_on_exec(int fd, const struct fdtable *fdt)
  82 {
  83         return FD_ISSET(fd, fdt->close_on_exec);
  84 }
  85
  86 #endif
  87
  88 #endif /* _LTTNG_WRAPPER_FDTABLE_H */