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. Link: http://lkml.kernel.org/r/cover.1413223900.git.ydrone...@opteya.com Cc: Al Viro <v...@zeniv.linux.org.uk> Cc: Andrew Morton <a...@linux-foundation.org> Signed-off-by: Yann Droneaud <ydrone...@opteya.com> --- include/linux/file.h | 1 - 1 file changed, 1 deletion(-) diff --git a/include/linux/file.h b/include/linux/file.h index 4d69123377a2..f87d30882a24 100644 --- a/include/linux/file.h +++ b/include/linux/file.h @@ -66,7 +66,6 @@ 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); -- 1.9.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
