File: tst-mmap-offset.c

package info (click to toggle)
glibc 2.28-8
  • links: PTS, VCS
  • area: main
  • in suites: bullseye, buster, experimental, sid
  • size: 271,788 kB
  • sloc: ansic: 1,008,637; asm: 259,607; makefile: 11,271; sh: 10,477; python: 6,910; cpp: 4,992; perl: 2,258; awk: 2,005; yacc: 290; pascal: 182; sed: 73
file content (118 lines) | stat: -rw-r--r-- 3,166 bytes parent folder | download | duplicates (4)
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
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
/* BZ #18877 and #21270 mmap offset test.

   Copyright (C) 2015-2018 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 <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <sys/mman.h>

#include <support/check.h>

static int fd;
static long int page_shift;
static char fname[] = "/tmp/tst-mmap-offset-XXXXXX";

static void
do_prepare (int argc, char **argv)
{
  fd = mkstemp64 (fname);
  if (fd < 0)
    FAIL_EXIT1 ("mkstemp failed");

  if (unlink (fname))
    FAIL_EXIT1 ("unlink failed");

  long sz = sysconf(_SC_PAGESIZE);
  if (sz == -1)
    sz = 4096L;
  page_shift = ffs (sz) - 1;
}

#define PREPARE do_prepare


/* Check if negative offsets are handled correctly by mmap.  */
static int
do_test_bz18877 (void)
{
  const int prot = PROT_READ | PROT_WRITE;
  const int flags = MAP_SHARED;
  const unsigned long length = 0x10000;
  const unsigned long offset = 0xace00000;
  const unsigned long size = offset + length;
  void *addr;

  if (ftruncate64 (fd, size))
    FAIL_RET ("ftruncate64 failed");

  addr = mmap (NULL, length, prot, flags, fd, offset);
  if (MAP_FAILED == addr)
    FAIL_RET ("mmap failed");

  /* This memcpy is likely to SIGBUS if mmap has messed up with offset.  */
  memcpy (addr, fname, sizeof (fname));

  return 0;
}

/* Check if invalid offset are handled correctly by mmap.  */
static int
do_test_bz21270 (void)
{
  /* For architectures with sizeof (off_t) < sizeof (off64_t) mmap is
     implemented with __SYS_mmap2 syscall and the offset is represented in
     multiples of page size.  For offset larger than
     '1 << (page_shift + 8 * sizeof (off_t))' (that is, 1<<44 on system with
     page size of 4096 bytes) the system call silently truncates the offset.
     For this case glibc mmap implementation returns EINVAL.  */
  const int prot = PROT_READ | PROT_WRITE;
  const int flags = MAP_SHARED;
  const int64_t offset = 1ULL << (page_shift + 8 * sizeof (uint32_t));
  const size_t length = 4096;

  void *addr = mmap64 (NULL, length, prot, flags, fd, offset);
  if (sizeof (off_t) < sizeof (off64_t))
    {
      if ((addr != MAP_FAILED) && (errno != EINVAL))
	FAIL_RET ("mmap succeed");
    }
  else
    {
      if (addr == MAP_FAILED)
	FAIL_RET ("mmap failed");
    }

  return 0;
}

int
do_test (void)
{
  int ret = 0;

  ret += do_test_bz18877 ();
  ret += do_test_bz21270 ();

  return ret;
}

#include <support/test-driver.c>