[PATCH] posix: Fix mmap for m68k and ia64 (BZ#21908)

[Adhemerval Zanella <adhemerval dot zanella at linaro dot org>]

Default semantic for mmap2 syscall is to take the offset in 4096-byte
units.  However m68k and ia64 mmap2 implementation take in the
configured pagesize units and for both architecture it can be
different values based on how kernel was built.

This patch fixes the m68k runtime discover of mmap2 offset unit
and adds the ia64 definition to find it at runtime.

Checked the basic tst-mmap and tst-mmap-offset on m68k (the system
is configured with 4k, so current code is already passing on this
system) and a sanity check on x86_64-linux-gnu (which should not be
affected by this change).  Sergei also states that ia64 loader now
work correctly with this change.

	Adhemerval Zanella  <adhemerval.zanella@linaro.org>
	Sergei Trofimovich  <slyfox@inbox.ru>

	* sysdeps/unix/sysv/linux/m68k/mmap_internal.h (MMAP2_PAGE_SHIFT):
	Rename to MMAP2_PAGE_UNIT.
	* sysdeps/unix/sysv/linux/mmap.c: Include mmap_internal iff
	__OFF_T_MATCHES_OFF64_T is not defined.
	* sysdeps/unix/sysv/linux/mmap_internal.h (page_unit): Declare as
	uint64_t.
	(MMAP2_PAGE_UNIT) [MMAP2_PAGE_UNIT == -1]: Redefine to page_unit.
	(page_unit) [MMAP2_PAGE_UNIT != -1]: Remove definition.
---
 ChangeLog                                    | 12 ++++++++++++
 sysdeps/unix/sysv/linux/ia64/mmap_internal.h | 29 ++++++++++++++++++++++++++++
 sysdeps/unix/sysv/linux/m68k/mmap_internal.h |  2 +-
 sysdeps/unix/sysv/linux/mmap.c               |  2 +-
 sysdeps/unix/sysv/linux/mmap_internal.h      |  6 +++---
 5 files changed, 46 insertions(+), 5 deletions(-)
 create mode 100644 sysdeps/unix/sysv/linux/ia64/mmap_internal.h

diff --git a/sysdeps/unix/sysv/linux/ia64/mmap_internal.h b/sysdeps/unix/sysv/linux/ia64/mmap_internal.h
new file mode 100644
index 0000000..dbaaa3f
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/ia64/mmap_internal.h
@@ -0,0 +1,29 @@
+/* Common mmap definition for Linux implementation.  Linux/ia64 version.
+   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_IA64_INTERNAL_LINUX_H
+#define MMAP_IA64_INTERNAL_LINUX_H
+
+/* Linux allows PAGE_SHIFT in range of [12-16] and expect
+   mmap2 offset to be provided in based on the configured pagesize.
+   Determine the shift dynamically with getpagesize.  */
+#define MMAP2_PAGE_UNIT -1
+
+#include_next <mmap_internal.h>
+
+#endif
diff --git a/sysdeps/unix/sysv/linux/m68k/mmap_internal.h b/sysdeps/unix/sysv/linux/m68k/mmap_internal.h
index bd8bd38..9fe9d91 100644
--- a/sysdeps/unix/sysv/linux/m68k/mmap_internal.h
+++ b/sysdeps/unix/sysv/linux/m68k/mmap_internal.h
@@ -22,7 +22,7 @@
 /* ColdFire and Sun 3 kernels have PAGE_SHIFT set to 13 and expect
    mmap2 offset to be provided in 8K pages.  Determine the shift
    dynamically with getpagesize.  */
-#define MMAP2_PAGE_SHIFT -1
+#define MMAP2_PAGE_UNIT -1
 
 #include_next <mmap_internal.h>
 
diff --git a/sysdeps/unix/sysv/linux/mmap.c b/sysdeps/unix/sysv/linux/mmap.c
index 98c2f88..59292b6 100644
--- a/sysdeps/unix/sysv/linux/mmap.c
+++ b/sysdeps/unix/sysv/linux/mmap.c
@@ -21,9 +21,9 @@
 #include <sys/mman.h>
 #include <sysdep.h>
 #include <stdint.h>
-#include <mmap_internal.h>
 
 #ifndef __OFF_T_MATCHES_OFF64_T
+# include <mmap_internal.h>
 
 /* An architecture may override this.  */
 # ifndef MMAP_ADJUST_OFFSET
diff --git a/sysdeps/unix/sysv/linux/mmap_internal.h b/sysdeps/unix/sysv/linux/mmap_internal.h
index 499e389..47c0991 100644
--- a/sysdeps/unix/sysv/linux/mmap_internal.h
+++ b/sysdeps/unix/sysv/linux/mmap_internal.h
@@ -27,13 +27,13 @@
 #endif
 
 #if MMAP2_PAGE_UNIT == -1
-static int page_unit;
-
+static uint64_t page_unit;
 # define MMAP_CHECK_PAGE_UNIT()			\
   if (page_unit == 0)				\
     page_unit = __getpagesize ();
+# undef MMAP2_PAGE_UNIT
+# define MMAP2_PAGE_UNIT page_unit
 #else
-# define page_unit MMAP2_PAGE_UNIT
 # define MMAP_CHECK_PAGE_UNIT()
 #endif
 
-- 
2.7.4