Consolidate Linux mmap implementation (BZ#21270)

This patch consolidates all Linux mmap implementations on default
sysdeps/unix/sysv/linux/mmap{64}.c one.  To accomodate all required
architecture specific requeriments a new internal header is created
(mmap_internal.h) where each architecture add its specific code
requirements.  Currently only x86_64 (to define MMAP_PREPARE to add
MAP_32BITS), s390 (which have a different kernel ABI for mmap), m68k
(which have variable minimum page sizes), and MIPS n32 (which zero
extend the offset to handle negative one correctly) redefine the new
header.

The patch also fixes BZ#21270 where default mmap64 on architectures
which uses mmap2 silent truncates large offsets value (larger than
1 << (page shift + 8 * sizeof (off_t)) or 1<<44 on architectures with
4096 bytes page size).  The new consolidate implementation returns
EINVAL as allowed by POSIX.

It also adds a tests for on current tst-mmap-offset one.  I have run
a full make check on x86_64, x86_64-32, i686, aarch64, armhf, powerpc,
powerpc64le, sparc64, and sparcv9 without any regressions.  I also ran
some basic tests (tst-mmap-offset) on sh4, m68k, and on qemu simulated
MIPS32 and MIPS64.

	[BZ #21270]
	* posix/tst-mmap-offset.c (do_prepare): New function.
	(do_test): Rename to do_test_bz18877 and use FAIL_RET.
	(do_test_bz21270): New function.
	* sysdeps/unix/sysv/linux/aarch64/mmap.c: Remove file.
	* sysdeps/unix/sysv/linux/arm/mmap.c: Remove file.
	* sysdeps/unix/sysv/linux/generic/wordsize-32/mmap.c: Likewise.
	* sysdeps/unix/sysv/linux/hppa/mmap.c: Likewise.
	* sysdeps/unix/sysv/linux/i386/mmap.c: Likewise.
	* sysdeps/unix/sysv/linux/m68k/mmap.S: Likewise.
	* sysdeps/unix/sysv/linux/m68k/mmap64.c: Likewise.
	* sysdeps/unix/sysv/linux/microblaze/mmap.S: Likewise.
	* sysdeps/unix/sysv/linux/mips/mips32/mmap.c: Likewise.
	* sysdeps/unix/sysv/linux/mips/mips64/n32/mmap.c: Likewise.
	* sysdeps/unix/sysv/linux/mips/mips64/n64/mmap64.c: Likewise.
	* sysdeps/unix/sysv/linux/s390/s390-32/mmap.S: Likewise.
	* sysdeps/unix/sysv/linux/s390/s390-32/mmap64.S: Likewise.
	* sysdeps/unix/sysv/linux/s390/s390-64/mmap.S: Likewise.
	* sysdeps/unix/sysv/linux/wordsize-64/mmap.c: Likewise.
	* sysdeps/unix/sysv/linux/wordsize-64/mmap64.c: Likewise.
	* sysdeps/unix/sysv/linux/x86_64/64/mmap.c: Likewise.
	* sysdeps/unix/sysv/linux/mmap_internal.h: New file.
	* sysdeps/unix/sysv/linux/m68k/mmap_internal.h: Likewise.
	* sysdeps/unix/sysv/linux/mips/mips64/n32/mmap_internal.h: Likewise.
	* sysdeps/unix/sysv/linux/s390/mmap_internal.h: Likewise.
	* sysdeps/unix/sysv/linux/x86_64/64/mmap_internal.h: Likewise.
	* sysdeps/unix/sysv/linux/mips/mips64/n64/syscalls.list: Remove mmap
	from auto-generation list.
	* sysdeps/unix/sysv/linux/mips/mips64/n32/syscalls.list: Likewise.
	* sysdeps/unix/sysv/linux/wordsize-64/syscalls.list: Likewise.
	* sysdeps/unix/sysv/linux/mmap.c: New file.
	* sysdeps/unix/sysv/linux/mmap64.c (__mmap64): Add check for invalid
	offsets and support for mmap2 syscall.

1 files changed, 49 insertions, 0 deletions

diff --git a/sysdeps/unix/sysv/linux/mmap_internal.h b/sysdeps/unix/sysv/linux/mmap_internal.h
new file mode 100644
index 0000000000..499e389605
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/mmap_internal.h
@@ -0,0 +1,49 @@
+/* Common mmap definition for Linux implementation.
+   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 MMAP_INTERNAL_LINUX_H
+#define MMAP_INTERNAL_LINUX_H 1
+
+/* This is the minimum mmap2 unit size accept by the kernel.  An architecture
+   with multiple minimum page sizes (such as m68k) might define it as -1 and
+   thus it will queried at runtime.  */
+#ifndef MMAP2_PAGE_UNIT
+# define MMAP2_PAGE_UNIT 4096ULL
+#endif
+
+#if MMAP2_PAGE_UNIT == -1
+static int page_unit;
+
+# define MMAP_CHECK_PAGE_UNIT()			\
+  if (page_unit == 0)				\
+    page_unit = __getpagesize ();
+#else
+# define page_unit MMAP2_PAGE_UNIT
+# define MMAP_CHECK_PAGE_UNIT()
+#endif
+
+/* Do not accept offset not multiple of page size.  */
+#define MMAP_OFF_LOW_MASK  (MMAP2_PAGE_UNIT - 1)
+
+/* An architecture may override this.  */
+#ifndef MMAP_CALL
+# define MMAP_CALL(__nr, __addr, __len, __prot, __flags, __fd, __offset) \
+  INLINE_SYSCALL_CALL (__nr, __addr, __len, __prot, __flags, __fd, __offset)
+#endif
+
+#endif /* MMAP_INTERNAL_LINUX_H  */