[newlib 07/65] Add a shm_open2 syscall to support upcoming memfd_create

[Sebastian Huber]

From: Kyle Evans <kevans at FreeBSD.org>

shm_open2 allows a little more flexibility than the original shm_open.
shm_open2 doesn't enforce CLOEXEC on its callers, and it has a separate
shmflag argument that can be expanded later. Currently the only shmflag is
to allow file sealing on the returned fd.

shm_open and memfd_create will both be implemented in libc to use this new
syscall.

__FreeBSD_version is bumped to indicate the presence.

Reviewed by:	kib, markj
Differential Revision:	https://reviews.freebsd.org/D21393
---
 newlib/libc/sys/rtems/include/sys/mman.h | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/newlib/libc/sys/rtems/include/sys/mman.h b/newlib/libc/sys/rtems/include/sys/mman.h
index f75490c96..6e178d83d 100644
--- a/newlib/libc/sys/rtems/include/sys/mman.h
+++ b/newlib/libc/sys/rtems/include/sys/mman.h
@@ -176,6 +176,12 @@
  * Anonymous object constant for shm_open().
  */
 #define	SHM_ANON		((char *)1)
+
+/*
+ * shmflags for shm_open2()
+ */
+#define	SHM_ALLOW_SEALING		0x00000001
+
 #endif /* __BSD_VISIBLE */
 
 /*
-- 
2.35.3