The gnulib module 'open' supports O_CLOEXEC since 2017-08-14. We can use it
to make multithreaded application that call fork() and exec() more robust.

Here are proposed patches.

How about module 'fts'? Should the directory fds that it allocates also be
made O_CLOEXEC?


2020-05-27  Bruno Haible  <bruno@clisp.org>

	relocatable-prog: Make more robust in multithreaded applications.
	* lib/progreloc.c (O_CLOEXEC): Define fallback to 0 when use from module
	relocatable-prog-wrapper.
	(find_executable): Pass an O_CLOEXEC flag to open().
	* modules/relocatable-prog (Depends-on): Add 'open'.

2020-05-27  Bruno Haible  <bruno@clisp.org>

	getloadavg: Make more robust in multithreaded applications.
	* lib/getloadavg.c (getloadavg): Pass an O_CLOEXEC flag to open().
	Simplify use of O_CLOEXEC.
	* modules/getloadavg (Depends-on): Add 'open'.

2020-05-27  Bruno Haible  <bruno@clisp.org>

	vma-iter: Make more robust in multithreaded applications.
	* lib/vma-iter.c (rof_open, vma_iterate): Pass an O_CLOEXEC flag to
	open().
	* modules/vma-iter (Depends-on): Add 'open'.

2020-05-27  Bruno Haible  <bruno@clisp.org>

	truncate: Make more robust in multithreaded applications.
	* lib/truncate.c (truncate): Pass an O_CLOEXEC flag to open().

2020-05-27  Bruno Haible  <bruno@clisp.org>

	pagealign_alloc: Make more robust in multithreaded applications.
	* lib/pagealign_alloc.c (pagealign_alloc): Pass an O_CLOEXEC flag to
	open().
	* modules/pagealign_alloc (Depends-on): Add 'open'.

2020-05-27  Bruno Haible  <bruno@clisp.org>

	openat: Make more robust in multithreaded applications.
	* lib/openat.c (openat_needs_fchdir): Pass an O_CLOEXEC flag to open().

2020-05-27  Bruno Haible  <bruno@clisp.org>

	at-internal: Make more robust in multithreaded applications.
	* lib/openat-proc.c (openat_proc_name): Pass an O_CLOEXEC flag to
	open().

2020-05-27  Bruno Haible  <bruno@clisp.org>

	mountlist: Make more robust in multithreaded applications.
	* lib/mountlist.c (read_file_system_list): Pass an O_CLOEXEC flag to
	open().
	* modules/mountlist (Depends-on): Add 'open'.

2020-05-27  Bruno Haible  <bruno@clisp.org>

	login_tty: Make more robust in multithreaded applications.
	* lib/login_tty.c (login_tty): Pass an O_CLOEXEC flag to open().
	* modules/login_tty (Depends-on): Add 'open'.

2020-05-27  Bruno Haible  <bruno@clisp.org>

	javacomp: Make more robust in multithreaded applications.
	* lib/javacomp.c (get_classfile_version): Pass an O_CLOEXEC flag to
	open().
	* modules/javacomp (Depends-on): Add 'open'.

2020-05-27  Bruno Haible  <bruno@clisp.org>

	getprogname: Make more robust in multithreaded applications.
	* lib/getprogname.c (getprogname): Pass an O_CLOEXEC flag to open().
	* modules/getprogname (Depends-on): Add 'open'.

2020-05-27  Bruno Haible  <bruno@clisp.org>

	get_progname_of: Make more robust in multithreaded applications.
	* lib/get_progname_of.c (get_progname_of): Pass an O_CLOEXEC flag to
	open().
	* modules/get_progname_of (Depends-on): Add 'open'.

2020-05-27  Bruno Haible  <bruno@clisp.org>

	get_ppid_of: Make more robust in multithreaded applications.
	* lib/get_ppid_of.c (get_ppid_of): Pass an O_CLOEXEC flag to open().
	* modules/get_ppid_of (Depends-on): Add 'open'.

2020-05-27  Bruno Haible  <bruno@clisp.org>

	get-rusage-as: Make more robust in multithreaded applications.
	* lib/get-rusage-as.c (get_rusage_as_via_setrlimit): Pass an O_CLOEXEC
	flag to open().
	* modules/get-rusage-as (Depends-on): Add 'open'.

2020-05-27  Bruno Haible  <bruno@clisp.org>

	crypto/gc: Make more robust in multithreaded applications.
	* lib/gc-gnulib.c (randomize): Pass an O_CLOEXEC flag to open().
	* modules/crypto/gc (Depends-on): Add 'open'.

2020-05-27  Bruno Haible  <bruno@clisp.org>

	copy-file: Make more robust in multithreaded applications.
	* lib/copy-file.c (qcopy_file_preserving): Pass an O_CLOEXEC flag to
	open().

2020-05-27  Bruno Haible  <bruno@clisp.org>

	chown: Make more robust in multithreaded applications.
	* lib/chown.c (rpl_chown): Pass an O_CLOEXEC flag to open().

2020-05-27  Bruno Haible  <bruno@clisp.org>

	doc: Fix statement about O_CLOEXEC (wrong since 2017-08-14).
	* doc/posix-headers/fcntl.texi: Gnulib no longer defines O_CLOEXEC to 0.