1 files changed, 18 insertions, 34 deletions

diff --git a/include/linux/fdtable.h b/include/linux/fdtable.h
index e066816f3519..c45306a9f007 100644
--- a/include/linux/fdtable.h
+++ b/include/linux/fdtable.h
@@ -22,7 +22,6 @@
  * as this is the granularity returned by copy_fdset().
  */
 #define NR_OPEN_DEFAULT BITS_PER_LONG
-#define NR_OPEN_MAX ~0U
 
 struct fdtable {
 	unsigned int max_fds;
@@ -33,16 +32,6 @@ struct fdtable {
 	struct rcu_head rcu;
 };
 
-static inline bool close_on_exec(unsigned int fd, const struct fdtable *fdt)
-{
-	return test_bit(fd, fdt->close_on_exec);
-}
-
-static inline bool fd_is_open(unsigned int fd, const struct fdtable *fdt)
-{
-	return test_bit(fd, fdt->open_fds);
-}
-
 /*
  * Open file table structure
  */
@@ -83,12 +72,17 @@ struct dentry;
 static inline struct file *files_lookup_fd_raw(struct files_struct *files, unsigned int fd)
 {
 	struct fdtable *fdt = rcu_dereference_raw(files->fdt);
-
-	if (fd < fdt->max_fds) {
-		fd = array_index_nospec(fd, fdt->max_fds);
-		return rcu_dereference_raw(fdt->fd[fd]);
-	}
-	return NULL;
+	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)
@@ -98,36 +92,26 @@ static inline struct file *files_lookup_fd_locked(struct files_struct *files, un
 	return files_lookup_fd_raw(files, fd);
 }
 
-static inline struct file *files_lookup_fd_rcu(struct files_struct *files, unsigned int fd)
+static inline bool close_on_exec(unsigned int fd, const struct files_struct *files)
 {
-	RCU_LOCKDEP_WARN(!rcu_read_lock_held(),
-			   "suspicious rcu_dereference_check() usage");
-	return files_lookup_fd_raw(files, fd);
+	return test_bit(fd, files_fdtable(files)->close_on_exec);
 }
 
-static inline struct file *lookup_fd_rcu(unsigned int fd)
-{
-	return files_lookup_fd_rcu(current->files, fd);
-}
-
-struct file *task_lookup_fd_rcu(struct task_struct *task, unsigned int fd);
-struct file *task_lookup_next_fd_rcu(struct task_struct *task, unsigned int *fd);
-
 struct task_struct;
 
 void put_files_struct(struct files_struct *fs);
 int unshare_files(void);
-struct files_struct *dup_fd(struct files_struct *, unsigned, int *) __latent_entropy;
+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 int __close_range(unsigned int fd, unsigned int max_fd, unsigned int flags);
-extern struct file *close_fd_get_file(unsigned int fd);
-extern int unshare_fd(unsigned long unshare_flags, unsigned int max_fds,
-		      struct files_struct **new_fdp);
+extern struct file *file_close_fd(unsigned int fd);
 
 extern struct kmem_cache *files_cachep;