kern: Allow O_CLOFORK to be passed to shm_open(2)

Signed-off-by: Ricardo Branco <rbranco@suse.de>

Reviewed by:	kib
Pull Request:	https://github.com/freebsd/freebsd-src/pull/1802

lib/libsys/shm_open.2

@@ -26,7 +26,7 @@
 .\" OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 .\" SUCH DAMAGE.
 .\"
-.Dd January 30, 2023
+.Dd August 4, 2025
 .Dt SHM_OPEN 2
 .Os
 .Sh NAME
@@ -74,8 +74,9 @@ must be included in
 The optional flags
 .Dv O_CREAT ,
 .Dv O_EXCL ,
+.Dv O_TRUNC ,
 and
-.Dv O_TRUNC
+.Dv O_CLOFORK
 may also be specified.
 .Pp
 If

sys/kern/uipc_shm.c

@@ -1160,7 +1160,8 @@ kern_shm_open2(struct thread *td, const char *userpath, int flags, mode_t mode,
 	if ((flags & O_ACCMODE) != O_RDONLY && (flags & O_ACCMODE) != O_RDWR)
 		return (EINVAL);
 
-	if ((flags & ~(O_ACCMODE | O_CREAT | O_EXCL | O_TRUNC | O_CLOEXEC)) != 0)
+	if ((flags & ~(O_ACCMODE | O_CREAT | O_EXCL | O_TRUNC | O_CLOEXEC |
+	    O_CLOFORK)) != 0)
 		return (EINVAL);
 
 	largepage = (shmflags & SHM_LARGEPAGE) != 0;