Fix MIPS mmap negative offset handling for consistency (bug 19550).

The handling of negative offsets in MIPS mmap is inconsistent with
other architectures, as shown by failure of the test
posix/tst-mmap-offset for o32 and n32.  The MIPS mmap syscall uses a
signed argument and does a signed arithmetic shift on it, whereas the
glibc semantics expected by that test are for the offset to be
considered as a large positive offset.  This patch makes MIPS
consistent with other architectures as far as possible by using the
mmap2 syscall on o32 (#including the generic implementation), and
making mmap not an alias for mmap64 for n32, with a custom
implementation for n32 that zero-extends the offset argument to 64-bit
before calling the mmap syscall.

Tested for MIPS64 (o32, n32, n64).

	[BZ #19550]
	* sysdeps/unix/sysv/linux/mips/mips32/mmap.c: New file.
	* sysdeps/unix/sysv/linux/mips/mips64/mmap64.c: Move to ....
	* sysdeps/unix/sysv/linux/mips/mips64/n64/mmap64.c: ... here.
	* sysdeps/unix/sysv/linux/mips/mips64/n32/mmap.c: New file.
	* sysdeps/unix/sysv/linux/mips/mips64/n32/syscalls.list (mmap64):
	New syscall entry.
	* sysdeps/unix/sysv/linux/mips/mips64/n64/syscalls.list (mmap):
	New syscall entry.
	* sysdeps/unix/sysv/linux/mips/mips64/syscalls.list (mmap): Remove
	syscall entry.

6 files changed, 40 insertions, 2 deletions

diff --git a/sysdeps/unix/sysv/linux/mips/mips32/mmap.c b/sysdeps/unix/sysv/linux/mips/mips32/mmap.c
new file mode 100644
index 0000000000..f30b1da58e
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/mips/mips32/mmap.c
@@ -0,0 +1 @@
+#include <sysdeps/unix/sysv/linux/generic/wordsize-32/mmap.c>
diff --git a/sysdeps/unix/sysv/linux/mips/mips64/n32/mmap.c b/sysdeps/unix/sysv/linux/mips/mips64/n32/mmap.c
new file mode 100644
index 0000000000..7afe776c7d
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/mips/mips64/n32/mmap.c
@@ -0,0 +1,35 @@
+/* mmap for MIPS n32.
+   Copyright (C) 2016 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/>.  */
+
+#include <sys/types.h>
+#include <sys/mman.h>
+#include <errno.h>
+#include <stdint.h>
+#include <sysdep.h>
+
+__ptr_t
+__mmap (__ptr_t addr, size_t len, int prot, int flags, int fd, off_t offset)
+{
+  /* To handle negative offsets consistently with other architectures,
+     the offset must be zero-extended to 64-bit.  */
+  uint64_t offset_adj = (uint64_t) (uint32_t) offset;
+  return (__ptr_t) INLINE_SYSCALL (mmap, 6, addr, len, prot, flags, fd,
+				   offset_adj);
+}
+
+weak_alias (__mmap, mmap)
diff --git a/sysdeps/unix/sysv/linux/mips/mips64/n32/syscalls.list b/sysdeps/unix/sysv/linux/mips/mips64/n32/syscalls.list
index 584ad1fcba..f55a94ac89 100644
--- a/sysdeps/unix/sysv/linux/mips/mips64/n32/syscalls.list
+++ b/sysdeps/unix/sysv/linux/mips/mips64/n32/syscalls.list
@@ -1,5 +1,7 @@
 # File name	Caller	Syscall name	# args	Strong name	Weak names
 
+mmap64		-	mmap		b:aniiii __mmap64	mmap64
+
 readahead	-	readahead	i:iii	__readahead	readahead
 sync_file_range	-	sync_file_range	Ci:iiii	sync_file_range
 
diff --git a/sysdeps/unix/sysv/linux/mips/mips64/mmap64.c b/sysdeps/unix/sysv/linux/mips/mips64/n64/mmap64.c
index 0dbd384a6a..0dbd384a6a 100644
--- a/sysdeps/unix/sysv/linux/mips/mips64/mmap64.c
+++ b/sysdeps/unix/sysv/linux/mips/mips64/n64/mmap64.c
diff --git a/sysdeps/unix/sysv/linux/mips/mips64/n64/syscalls.list b/sysdeps/unix/sysv/linux/mips/mips64/n64/syscalls.list
index b23a2a1d1c..890a74494a 100644
--- a/sysdeps/unix/sysv/linux/mips/mips64/n64/syscalls.list
+++ b/sysdeps/unix/sysv/linux/mips/mips64/n64/syscalls.list
@@ -1,5 +1,7 @@
 # File name	Caller	Syscall name	# args	Strong name	Weak names
 
+mmap		-	mmap		b:aniiii __mmap		mmap __mmap64 mmap64
+
 sync_file_range	-	sync_file_range	Ci:iiii	sync_file_range
 
 prlimit		EXTRA	prlimit64	i:iipp	prlimit		prlimit64
diff --git a/sysdeps/unix/sysv/linux/mips/mips64/syscalls.list b/sysdeps/unix/sysv/linux/mips/mips64/syscalls.list
index 6c80e27f75..66cc687abb 100644
--- a/sysdeps/unix/sysv/linux/mips/mips64/syscalls.list
+++ b/sysdeps/unix/sysv/linux/mips/mips64/syscalls.list
@@ -2,8 +2,6 @@
 
 lseek		-	lseek		i:iii	__libc_lseek	__lseek lseek __llseek llseek __libc_lseek64 __lseek64 lseek64
 
-mmap		-	mmap		b:aniiii __mmap		mmap __mmap64 mmap64
-
 ftruncate	-	ftruncate	i:ii	__ftruncate	ftruncate ftruncate64 __ftruncate64
 truncate	-	truncate	i:si	truncate	truncate64