[PATCH v4 7/7] file: remove get_unused_fd() macro

[Yann Droneaud]

Macro get_unused_fd() allocates a file descriptor without O_CLOEXEC flag.

This can be seen as an unsafe default: in most case O_CLOEXEC
must be used to not leak file descriptor across exec().

Using O_CLOEXEC by default allows userspace to choose, without race,
if the file descriptor is going to be inherited across exec(),
by calling fcntl() when needed.

This patch removes get_unused_fd() so that newer kernel code use
anon_inode_getfd() or get_unused_fd_flags() with flags provided
by userspace. If flags cannot be given by userspace, O_CLOEXEC must be
used by default.

Signed-off-by: Yann Droneaud <ydroneaud@xxxxxxxxxx>
Link: http://lkml.kernel.org/r/cover.1383121137.git.ydroneaud@xxxxxxxxxx
---
 include/linux/file.h | 1 -
 1 file changed, 1 deletion(-)

diff --git a/include/linux/file.h b/include/linux/file.h
index cbacf4f..8666002 100644
--- a/include/linux/file.h
+++ b/include/linux/file.h
@@ -63,7 +63,6 @@ extern void set_close_on_exec(unsigned int fd, int flag);
 extern bool get_close_on_exec(unsigned int fd);
 extern void put_filp(struct file *);
 extern int get_unused_fd_flags(unsigned flags);
-#define get_unused_fd() get_unused_fd_flags(0)
 extern void put_unused_fd(unsigned int fd);
 
 extern void fd_install(unsigned int fd, struct file *file);
-- 
1.8.3.1

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