lib{spl,[uz]util}: set O_CLOEXEC on all fds

As found by
  git grep -E '(open|setmntent|pipe2?)\(' |
    grep -vE '((zfs|zpool)_|fd|dl|lzc_re|pidfile_|g_)open\('

uu_open_tmp() is unused here and seems very unmaintained,
maybe it's time to get rid of it?

Signed-off-by: Ahelenia Ziemiańska <[email protected]>

Author: nabijaczleweli

lib/libspl/os/linux/gethostid.c

@@ -45,7 +45,7 @@ get_spl_hostid(void)
 		return (hostid & HOSTID_MASK);
 	}
 
-	f = fopen("/sys/module/spl/parameters/spl_hostid", "r");
+	f = fopen("/sys/module/spl/parameters/spl_hostid", "re");
 	if (!f)
 		return (0);
 
@@ -74,7 +74,7 @@ get_system_hostid(void)
 		unsigned long hostid;
 		int hostid_size = 4;  /* 4 bytes regardless of arch */
 
-		fd = open("/etc/hostid", O_RDONLY);
+		fd = open("/etc/hostid", O_RDONLY | O_CLOEXEC);
 		if (fd >= 0) {
 			rc = read(fd, &hostid, hostid_size);
 			if (rc > 0)

lib/libspl/os/linux/getmntany.c

@@ -128,9 +128,9 @@ getextmntent(const char *path, struct extmnttab *entry, struct stat64 *statbuf)
 
 
 #ifdef HAVE_SETMNTENT
-	if ((fp = setmntent(MNTTAB, "r")) == NULL) {
+	if ((fp = setmntent(MNTTAB, "re")) == NULL) {
 #else
-	if ((fp = fopen(MNTTAB, "r")) == NULL) {
+	if ((fp = fopen(MNTTAB, "re")) == NULL) {
 #endif
 		(void) fprintf(stderr, "cannot open %s\n", MNTTAB);
 		return (-1);

lib/libuutil/uu_open.c

@@ -36,12 +36,6 @@
 #include <stdio.h>
 #include <unistd.h>
 
-#ifdef _LP64
-#define	TMPPATHFMT	"%s/uu%ld"
-#else /* _LP64 */
-#define	TMPPATHFMT	"%s/uu%lld"
-#endif /* _LP64 */
-
 /*ARGSUSED*/
 int
 uu_open_tmp(const char *dir, uint_t uflags)
@@ -55,7 +49,7 @@ uu_open_tmp(const char *dir, uint_t uflags)
 	for (;;) {
 		(void) snprintf(fname, PATH_MAX, "%s/uu%lld", dir, gethrtime());
 
-		f = open(fname, O_CREAT | O_EXCL | O_RDWR, 0600);
+		f = open(fname, O_CREAT | O_EXCL | O_RDWR | O_CLOEXEC, 0600);
 
 		if (f >= 0 || errno != EEXIST)
 			break;

lib/libzutil/os/freebsd/zutil_import_os.c

@@ -127,7 +127,7 @@ zpool_open_func(void *arg)
 	/*
 	 * O_NONBLOCK so we don't hang trying to open things like serial ports.
 	 */
-	if ((fd = open(rn->rn_name, O_RDONLY|O_NONBLOCK)) < 0)
+	if ((fd = open(rn->rn_name, O_RDONLY|O_NONBLOCK|O_CLOEXEC)) < 0)
 		return;
 
 	/*

lib/libzutil/os/linux/zutil_device_path_os.c

@@ -390,7 +390,7 @@ zfs_dev_is_whole_disk(const char *dev_name)
 	struct dk_gpt *label;
 	int fd;
 
-	if ((fd = open(dev_name, O_RDONLY | O_DIRECT)) < 0)
+	if ((fd = open(dev_name, O_RDONLY | O_DIRECT | O_CLOEXEC)) < 0)
 		return (B_FALSE);
 
 	if (efi_alloc_and_init(fd, EFI_NUMPAR, &label) != 0) {

lib/libzutil/os/linux/zutil_import_os.c

@@ -136,9 +136,9 @@ zpool_open_func(void *arg)
 	 * cache which may be stale for multipath devices.  An EINVAL errno
 	 * indicates O_DIRECT is unsupported so fallback to just O_RDONLY.
 	 */
-	fd = open(rn->rn_name, O_RDONLY | O_DIRECT);
+	fd = open(rn->rn_name, O_RDONLY | O_DIRECT | O_CLOEXEC);
 	if ((fd < 0) && (errno == EINVAL))
-		fd = open(rn->rn_name, O_RDONLY);
+		fd = open(rn->rn_name, O_RDONLY | O_CLOEXEC);
 	if ((fd < 0) && (errno == EACCES))
 		hdl->lpc_open_access_error = B_TRUE;
 	if (fd < 0)

lib/libzutil/zutil_import.c

@@ -1345,7 +1345,8 @@ zpool_find_import_impl(libpc_handle_t *hdl, importargs_t *iarg,
 				 * would prevent a zdb -e of active pools with
 				 * no cachefile.
 				 */
-				fd = open(slice->rn_name, O_RDONLY | O_EXCL);
+				fd = open(slice->rn_name,
+				    O_RDONLY | O_EXCL | O_CLOEXEC);
 				if (fd >= 0 || iarg->can_be_active) {
 					if (fd >= 0)
 						close(fd);
@@ -1437,7 +1438,7 @@ zpool_find_import_cached(libpc_handle_t *hdl, importargs_t *iarg)
 
 	verify(iarg->poolname == NULL || iarg->guid == 0);
 
-	if ((fd = open(iarg->cachefile, O_RDONLY)) < 0) {
+	if ((fd = open(iarg->cachefile, O_RDONLY | O_CLOEXEC)) < 0) {
 		zutil_error_aux(hdl, "%s", strerror(errno));
 		(void) zutil_error(hdl, EZFS_BADCACHE,
 		    dgettext(TEXT_DOMAIN, "failed to open cache file"));