Use O_RDONLY since you are not supposed to write to a directory.
Use O_DIRECTORY as mandated by POSIX (The Open Group Base Specifications
Issue 7, 2018 edition IEEE Std 1003.1-2017):
"If the type DIR is implemented using a file descriptor, the descriptor
shall be obtained as if the O_DIRECTORY flag was passed to open()."
Use O_CLOEXEC as mandated by POSIX:
"When a file descriptor is used to implement the directory stream, it
behaves as if the FD_CLOEXEC had been set for the file descriptor."
Drop the fcntl() call in favour of O_CLOEXEC.
Signed-off-by: Sebastian Huber <sebastian.huber@embedded-brains.de>
* libc/posix/opendir.c (opendir): Change code to check
for HAVE_FCNTL before calling fcntl.
* libc/search/hash.c (hash_open): Ditto.
* libc/search/hash_page.c (open_tmp): Ditto.
* libc/reent/Makefile.am: Add fcntlr.c.
* libc/reent/Makefile.in: Regenerated.
* libc/reent/fcntlr.c: New file.
* libc/stdio/fdopen.c (_fdopen_r): Change to call _fcntl_r
instead of _fcntl when HAVE_FCNTL flag is set.
* libc/syscalls/sysfcntl.c (fcntl): Check for HAVE_FCNTL flag
to see if _fcntl or _fcntl_r should be called. If flag is not
set, default to ENOSYS stub.
Sebastian Huber