f938612dd9
Macro get_unused_fd() is used to allocate a file descriptor with default flags. Those default flags (0) don't enable close-on-exec. This can be seen as an unsafe default: in most case close-on-exec should be enabled to not leak file descriptor across exec(). It would be better to have a "safer" default set of flags, eg. O_CLOEXEC must be used to enable close-on-exec. Instead this patch removes get_unused_fd() so that out of tree modules won't be affect by a runtime behavor change which might introduce other kind of bugs: it's better to catch the change at build time, making it easier to fix. Removing the macro will also promote use of get_unused_fd_flags() (or anon_inode_getfd()) with flags provided by userspace. Or, if flags cannot be given by userspace, with flags set to O_CLOEXEC by default. Signed-off-by: Yann Droneaud <ydroneaud@opteya.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
77 lines
1.7 KiB
C
77 lines
1.7 KiB
C
/*
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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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struct file;
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extern void fput(struct file *);
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struct file_operations;
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struct vfsmount;
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struct dentry;
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struct path;
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extern struct file *alloc_file(struct path *, fmode_t mode,
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const struct file_operations *fop);
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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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struct fd {
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struct file *file;
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unsigned int flags;
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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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static inline void fdput(struct fd fd)
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{
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if (fd.flags & FDPUT_FPUT)
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fput(fd.file);
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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 unsigned long __fdget(unsigned int fd);
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extern unsigned long __fdget_raw(unsigned int fd);
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extern unsigned long __fdget_pos(unsigned int fd);
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static inline struct fd __to_fd(unsigned long v)
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{
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return (struct fd){(struct file *)(v & ~3),v & 3};
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}
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static inline struct fd fdget(unsigned int fd)
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{
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return __to_fd(__fdget(fd));
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}
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static inline struct fd fdget_raw(unsigned int fd)
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{
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return __to_fd(__fdget_raw(fd));
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}
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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 void put_filp(struct file *);
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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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extern void fd_install(unsigned int fd, struct file *file);
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extern void flush_delayed_fput(void);
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extern void __fput_sync(struct file *);
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#endif /* __LINUX_FILE_H */
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