aboutsummaryrefslogtreecommitdiff
path: root/sysdeps/generic/bp-checks.h
blob: 41ffad71e19e113bda89f10609f8a25f4839407d (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
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
119
120
121
122
123
124
125
126
127
128
129
130
131
/* Bounded-pointer checking macros for C.
   Copyright (C) 2000 Free Software Foundation, Inc.
   Contributed by Greg McGary <greg@mcgary.org>

   This file is part of the GNU C Library.  Its master source is NOT part of
   the C library, however.  The master source lives in the GNU MP Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Library General Public License as
   published by the Free Software Foundation; either version 2 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
   Library General Public License for more details.

   You should have received a copy of the GNU Library General Public
   License along with the GNU C Library; see the file COPYING.LIB.  If not,
   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
   Boston, MA 02111-1307, USA.  */

#ifndef _bp_checks_h_
#define _bp_checks_h_ 1

#if __BOUNDED_POINTERS__

# define BOUNDS_VIOLATED (__builtin_trap (), 0)

/* Verify that pointer's value >= low.  Return pointer value.  */
# define CHECK_BOUNDS_LOW(ARG)					\
  (((__ptrvalue (ARG) < __ptrlow (ARG)) && BOUNDS_VIOLATED),	\
   __ptrvalue (ARG))

/* Verify that pointer's value < high.  Return pointer value.  */
# define CHECK_BOUNDS_HIGH(ARG)				\
  (((__ptrvalue (ARG) > __ptrhigh (ARG)) && BOUNDS_VIOLATED),	\
   __ptrvalue (ARG))

# define _CHECK_N(ARG, N, COND)				\
  (((COND)						\
    && (__ptrvalue (ARG) < __ptrlow (ARG)		\
	|| __ptrvalue (ARG) + (N) > __ptrhigh (ARG))	\
    && BOUNDS_VIOLATED),				\
   __ptrvalue (ARG))

extern void *__unbounded __ubp_memchr (const void *__unbounded, int, unsigned);

# define _CHECK_STRING(ARG, COND)				\
  (((COND)							\
    && (__ptrvalue (ARG) < __ptrlow (ARG)			\
	|| !__ubp_memchr (__ptrvalue (ARG), '\0',			\
		      (__ptrhigh (ARG) - __ptrvalue (ARG))))	\
    && BOUNDS_VIOLATED),					\
   __ptrvalue (ARG))

/* Check bounds of a pointer seated to an array of N objects.  */
# define CHECK_N(ARG, N) _CHECK_N ((ARG), (N), 1)
/* Same as CHECK_N, but tolerate ARG == NULL.  */
# define CHECK_N_NULL_OK(ARG, N) _CHECK_N ((ARG), (N), __ptrvalue (ARG))

/* Check bounds of a pointer seated to a single object.  */
# define CHECK_1(ARG) CHECK_N ((ARG), 1)
/* Same as CHECK_1, but tolerate ARG == NULL.  */
# define CHECK_1_NULL_OK(ARG) CHECK_N_NULL_OK ((ARG), 1)

/* Check for NUL-terminator within string's bounds.  */
# define CHECK_STRING(ARG) _CHECK_STRING ((ARG), 1)
/* Same as CHECK_STRING, but tolerate ARG == NULL.  */
# define CHECK_STRING_NULL_OK(ARG) _CHECK_STRING ((ARG), __ptrvalue (ARG))

/* Check bounds of signal syscall args with type sigset_t.  */
# define CHECK_SIGSET(SET) CHECK_N ((SET), _NSIG / (8 * sizeof *(SET)))
/* Same as CHECK_SIGSET, but tolerate SET == NULL.  */
# define CHECK_SIGSET_NULL_OK(SET) CHECK_N_NULL_OK ((SET), _NSIG / (8 * sizeof *(SET)))

# if defined (_IOC_SIZESHIFT) && defined (_IOC_SIZEBITS)
/* Extract the size of the ioctl data and check its bounds.  */
#  define CHECK_IOCTL(ARG, CMD)						\
  CHECK_N ((const char *) (ARG),					\
	   (((CMD) >> _IOC_SIZESHIFT) & ((1 << _IOC_SIZEBITS) - 1)))
# else
/* We don't know the size of the ioctl data, so the best we can do
   is check that the first byte is within bounds.  */
#  define CHECK_IOCTL(ARG, CMD) CHECK_1 ((const char *) ARG)
# endif

/* Check bounds of `struct flock *' for the locking fcntl commands.  */
# define CHECK_FCNTL(ARG, CMD)					\
  (((CMD) == F_GETLK || (CMD) == F_SETLK || (CMD) == F_SETLKW)	\
   ? CHECK_1 ((struct flock *) ARG) : (unsigned long) (ARG))

/* Check bounds of an array of mincore residency-status flags that
   cover a region of NBYTES.  Such a vector occupies one byte per page
   of memory.  */
# define CHECK_N_PAGES(ARG, NBYTES)				\
  ({ int _page_size_ = sysconf (_SC_PAGE_SIZE);			\
     CHECK_N ((const char *) (ARG),				\
	      ((NBYTES) + _page_size_ - 1) / _page_size_); })

/* Return a bounded pointer with value PTR that satisfies CHECK_N (PTR, N).  */
# define BOUNDED_N(PTR, N) 				\
  ({ __typeof (PTR) __bounded _p_;			\
     __ptrvalue _p_ = __ptrlow _p_ = __ptrvalue (PTR);	\
     __ptrhigh _p_ = __ptrvalue _p_ + (N);		\
     _p_; })

#else /* !__BOUNDED_POINTERS__ */

/* Do nothing if not compiling with -fbounded-pointers.  */

# define BOUNDS_VIOLATED
# define CHECK_BOUNDS_LOW(ARG) (ARG)
# define CHECK_BOUNDS_HIGH(ARG) (ARG)
# define CHECK_1(ARG) (ARG)
# define CHECK_1_NULL_OK(ARG) (ARG)
# define CHECK_N(ARG, N) (ARG)
# define CHECK_N_NULL_OK(ARG, N) (ARG)
# define CHECK_STRING(ARG) (ARG)
# define CHECK_SIGSET(SET) (SET)
# define CHECK_SIGSET_NULL_OK(SET) (SET)
# define CHECK_IOCTL(ARG, CMD) (ARG)
# define CHECK_FCNTL(ARG, CMD) (ARG)
# define CHECK_N_PAGES(ARG, NBYTES) (ARG)
# define BOUNDED_N(PTR, N) (PTR)

#endif /* !__BOUNDED_POINTERS__ */

#define BOUNDED_1(PTR) BOUNDED_N (PTR, 1)

#endif /* _bp_checks_h_ */