posix: Fix large mmap64 offset for mips64n32 (BZ#24699)

The fix for BZ#21270 (commit 158d5fa0e19) added a mask to avoid offset larger
than 1^44 to be used along __NR_mmap2.  However mips64n32 users __NR_mmap,
as mips64n64, but still defines off_t as old non-LFS type (other ILP32, such
x32, defines off_t being equal to off64_t).  This leads to use the same
mask meant only for __NR_mmap2 call for __NR_mmap, thus limiting the maximum
offset it can use with mmap64.

This patch fixes by setting the high mask only for __NR_mmap2 usage. The
posix/tst-mmap-offset.c already tests it and also fails for mips64n32. The
patch also change the test to check for an arch-specific header that defines
the maximum supported offset.

Checked on x86_64-linux-gnu, i686-linux-gnu, and I also tests tst-mmap-offset
on qemu simulated mips64 with kernel 3.2.0 kernel for both mips-linux-gnu and
mips64-n32-linux-gnu.

	[BZ #24699]
	* posix/tst-mmap-offset.c: Mention BZ #24699.
	(do_test_bz21270): Rename to do_test_large_offset and use
	mmap64_maximum_offset to check for maximum expected offset value.
	* sysdeps/generic/mmap_info.h: New file.
	* sysdeps/unix/sysv/linux/mips/mmap_info.h: Likewise.
	* sysdeps/unix/sysv/linux/mmap64.c (MMAP_OFF_HIGH_MASK): Define iff
	__NR_mmap2 is used.

1 files changed, 5 insertions, 4 deletions

diff --git a/posix/tst-mmap-offset.c b/posix/tst-mmap-offset.c
index 676c52845f..d4e53c3e67 100644
--- a/posix/tst-mmap-offset.c
+++ b/posix/tst-mmap-offset.c
@@ -1,4 +1,4 @@
-/* BZ #18877 and #21270 mmap offset test.
+/* BZ #18877, BZ #21270, and BZ #24699 mmap offset test.
 
    Copyright (C) 2015-2019 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
@@ -24,6 +24,7 @@
 #include <unistd.h>
 #include <errno.h>
 #include <sys/mman.h>
+#include <mmap_info.h>
 
 #include <support/check.h>
 
@@ -76,7 +77,7 @@ do_test_bz18877 (void)
 
 /* Check if invalid offset are handled correctly by mmap.  */
 static int
-do_test_bz21270 (void)
+do_test_large_offset (void)
 {
   /* For architectures with sizeof (off_t) < sizeof (off64_t) mmap is
      implemented with __SYS_mmap2 syscall and the offset is represented in
@@ -90,7 +91,7 @@ do_test_bz21270 (void)
   const size_t length = 4096;
 
   void *addr = mmap64 (NULL, length, prot, flags, fd, offset);
-  if (sizeof (off_t) < sizeof (off64_t))
+  if (mmap64_maximum_offset (page_shift) < UINT64_MAX)
     {
       if ((addr != MAP_FAILED) && (errno != EINVAL))
 	FAIL_RET ("mmap succeed");
@@ -110,7 +111,7 @@ do_test (void)
   int ret = 0;
 
   ret += do_test_bz18877 ();
-  ret += do_test_bz21270 ();
+  ret += do_test_large_offset ();
 
   return ret;
 }