blob: 34a708e22bad64eee2ab26f3a645cd8ff9ffb38c (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
|
/* Should strace show byte or page offsets in mmap syscalls
* which take page offset parameters?
*
* At the time of writing, sys_mmap() converts page to byte offsets,
* but only for SH64! But this routine is used on i386 too - by mmap2 syscall,
* which uses page offsets too. As it stands now, SH64 and i386 are inconsistent.
*
* sys_old_mmap() is used for old mmap syscall, which uses byte offset -
* should be ok.
* sys_mmap64() is currently buggy (should print bogus offset, but I can't
* test it right now. What arch/bitness invokes sys_mmap64?)
*
* This program is intended for testing what strace actually shows. Usage:
* $ gcc test/mmap_offset_decode.c -o mmap_offset_decode -static
* $ strace ./mmap_offset_decode
*
* As of today (2011-08), on i386 strace prints page offset.
* Fixed 2013-02-19. Now all mmaps on all arches should show byte offsets.
*/
#define _LARGEFILE_SOURCE
#define _LARGEFILE64_SOURCE
#define _FILE_OFFSET_BITS 64
#include <sys/mman.h>
#include <errno.h>
int main()
{
/* 0x1000 is meant to be page size multiplier */
mmap(0, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1,
0x7fff0000LL * 0x1000);
return errno != 0;
}
|
