Linux: Introduce <bits/mman-shared.h>

This header file enables sharing of portable declarations and
definitions across all Linux architectures, including hppa (which does
not use <bits/mman-linux.h>).

Reviewed-by: Carlos O'Donell <carlos@redhat.com>

ChangeLog

@@ -1,3 +1,16 @@
+2017-11-24  Florian Weimer  <fweimer@redhat.com>
+
+	* sysdeps/unix/sysv/linux/Makefile (sysdep_headers): Add
+	bits/mman-shared.h.
+	* sysdeps/unix/sysv/linux/bits/mman-linux.h: Include
+	<bits/mman-shared.h>.
+	(MFD_CLOEXEC, MFD_ALLOW_SEALING, MFD_HUGETLB, memfd_create): Move
+	to ...
+	* sysdeps/unix/sysv/linux/bits/mman-shared.h: ... this new file.
+	Add #ifndef guard for the MFD_* constants based on MFD_CLOEXEC.
+	* sysdeps/unix/sysv/linux/hppa/bits/mman.h: Include
+	<bits/mman-shared.h>.
+
 2017-11-24  Adhemerval Zanella  <adhemerval.zanella@linaro.org>
 
 	[BZ #22457]

sysdeps/unix/sysv/linux/Makefile

@@ -39,7 +39,7 @@ sysdep_headers += sys/mount.h sys/acct.h sys/sysctl.h \
 		  sys/timerfd.h sys/fanotify.h bits/eventfd.h bits/inotify.h \
 		  bits/signalfd.h bits/timerfd.h bits/epoll.h \
 		  bits/socket_type.h bits/syscall.h bits/sysctl.h \
-		  bits/mman-linux.h \
+		  bits/mman-linux.h bits/mman-shared.h \
 		  bits/siginfo-arch.h bits/siginfo-consts-arch.h
 
 tests += tst-clone tst-clone2 tst-clone3 tst-fanotify tst-personality \

sysdeps/unix/sysv/linux/bits/mman-linux.h

@@ -112,18 +112,4 @@
 					   faulted in.  */
 #endif
 
-#ifdef __USE_GNU
+#include <bits/mman-shared.h>
-/* Flags for memfd_create.  */
-# define MFD_CLOEXEC 1U
-# define MFD_ALLOW_SEALING 2U
-# define MFD_HUGETLB 4U
-
-__BEGIN_DECLS
-
-/* Create a new memory file descriptor.  NAME is a name for debugging.
-   FLAGS is a combination of the MFD_* constants.  */
-int memfd_create (const char *__name, unsigned int __flags) __THROW;
-
-__END_DECLS
-
-#endif /* __USE_GNU */

sysdeps/unix/sysv/linux/bits/mman-shared.h

@@ -0,0 +1,39 @@
+/* Memory-mapping-related declarations/definitions, not architecture-specific.
+   Copyright (C) 2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#ifndef _SYS_MMAN_H
+# error "Never use <bits/mman-shared.h> directly; include <sys/mman.h> instead."
+#endif
+
+#ifdef __USE_GNU
+/* Flags for memfd_create.  */
+# ifndef MFD_CLOEXEC
+#  define MFD_CLOEXEC 1U
+#  define MFD_ALLOW_SEALING 2U
+#  define MFD_HUGETLB 4U
+# endif
+
+__BEGIN_DECLS
+
+/* Create a new memory file descriptor.  NAME is a name for debugging.
+   FLAGS is a combination of the MFD_* constants.  */
+int memfd_create (const char *__name, unsigned int __flags) __THROW;
+
+__END_DECLS
+
+#endif /* __USE_GNU */

sysdeps/unix/sysv/linux/hppa/bits/mman.h

@@ -110,3 +110,5 @@
 # define POSIX_MADV_WILLNEED	3 /* Will need these pages.  */
 # define POSIX_MADV_DONTNEED	4 /* Don't need these pages.  */
 #endif
+
+#include <bits/mman-shared.h>