1 |
148 |
jeremybenn |
/* Bounded-pointer checking macros for C.
|
2 |
|
|
Copyright (C) 2000 Free Software Foundation, Inc.
|
3 |
|
|
This file is part of the GNU C Library.
|
4 |
|
|
Contributed by Greg McGary <greg@mcgary.org>
|
5 |
|
|
|
6 |
|
|
The GNU C Library is free software; you can redistribute it and/or
|
7 |
|
|
modify it under the terms of the GNU Lesser General Public
|
8 |
|
|
License as published by the Free Software Foundation; either
|
9 |
|
|
version 2.1 of the License, or (at your option) any later version.
|
10 |
|
|
|
11 |
|
|
The GNU C Library is distributed in the hope that it will be useful,
|
12 |
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
13 |
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
14 |
|
|
Lesser General Public License for more details.
|
15 |
|
|
|
16 |
|
|
You should have received a copy of the GNU Lesser General Public
|
17 |
|
|
License along with the GNU C Library; if not, write to the Free
|
18 |
|
|
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
|
19 |
|
|
02111-1307 USA. */
|
20 |
|
|
|
21 |
|
|
#ifndef _bp_checks_h_
|
22 |
|
|
#define _bp_checks_h_ 1
|
23 |
|
|
|
24 |
|
|
#if __BOUNDED_POINTERS__
|
25 |
|
|
|
26 |
|
|
# define BOUNDS_VIOLATED (__builtin_trap (), 0)
|
27 |
|
|
|
28 |
|
|
/* Verify that pointer's value >= low. Return pointer value. */
|
29 |
|
|
# define CHECK_BOUNDS_LOW(ARG) \
|
30 |
|
|
(((__ptrvalue (ARG) < __ptrlow (ARG)) && BOUNDS_VIOLATED), \
|
31 |
|
|
__ptrvalue (ARG))
|
32 |
|
|
|
33 |
|
|
/* Verify that pointer's value < high. Return pointer value. */
|
34 |
|
|
# define CHECK_BOUNDS_HIGH(ARG) \
|
35 |
|
|
(((__ptrvalue (ARG) > __ptrhigh (ARG)) && BOUNDS_VIOLATED), \
|
36 |
|
|
__ptrvalue (ARG))
|
37 |
|
|
|
38 |
|
|
# define _CHECK_N(ARG, N, COND) \
|
39 |
|
|
(((COND) \
|
40 |
|
|
&& (__ptrvalue (ARG) < __ptrlow (ARG) \
|
41 |
|
|
|| __ptrvalue (ARG) + (N) > __ptrhigh (ARG)) \
|
42 |
|
|
&& BOUNDS_VIOLATED), \
|
43 |
|
|
__ptrvalue (ARG))
|
44 |
|
|
|
45 |
|
|
extern void *__unbounded __ubp_memchr (const void *__unbounded, int, unsigned);
|
46 |
|
|
|
47 |
|
|
# define _CHECK_STRING(ARG, COND) \
|
48 |
|
|
(((COND) \
|
49 |
|
|
&& (__ptrvalue (ARG) < __ptrlow (ARG) \
|
50 |
|
|
|| !__ubp_memchr (__ptrvalue (ARG), '\0', \
|
51 |
|
|
(__ptrhigh (ARG) - __ptrvalue (ARG)))) \
|
52 |
|
|
&& BOUNDS_VIOLATED), \
|
53 |
|
|
__ptrvalue (ARG))
|
54 |
|
|
|
55 |
|
|
/* Check bounds of a pointer seated to an array of N objects. */
|
56 |
|
|
# define CHECK_N(ARG, N) _CHECK_N ((ARG), (N), 1)
|
57 |
|
|
/* Same as CHECK_N, but tolerate ARG == NULL. */
|
58 |
|
|
# define CHECK_N_NULL_OK(ARG, N) _CHECK_N ((ARG), (N), __ptrvalue (ARG))
|
59 |
|
|
|
60 |
|
|
/* Check bounds of a pointer seated to a single object. */
|
61 |
|
|
# define CHECK_1(ARG) CHECK_N ((ARG), 1)
|
62 |
|
|
/* Same as CHECK_1, but tolerate ARG == NULL. */
|
63 |
|
|
# define CHECK_1_NULL_OK(ARG) CHECK_N_NULL_OK ((ARG), 1)
|
64 |
|
|
|
65 |
|
|
/* Check for NUL-terminator within string's bounds. */
|
66 |
|
|
# define CHECK_STRING(ARG) _CHECK_STRING ((ARG), 1)
|
67 |
|
|
/* Same as CHECK_STRING, but tolerate ARG == NULL. */
|
68 |
|
|
# define CHECK_STRING_NULL_OK(ARG) _CHECK_STRING ((ARG), __ptrvalue (ARG))
|
69 |
|
|
|
70 |
|
|
/* Check bounds of signal syscall args with type sigset_t. */
|
71 |
|
|
# define CHECK_SIGSET(SET) CHECK_N ((SET), _NSIG / (8 * sizeof *(SET)))
|
72 |
|
|
/* Same as CHECK_SIGSET, but tolerate SET == NULL. */
|
73 |
|
|
# define CHECK_SIGSET_NULL_OK(SET) CHECK_N_NULL_OK ((SET), _NSIG / (8 * sizeof *(SET)))
|
74 |
|
|
|
75 |
|
|
# if defined (_IOC_SIZESHIFT) && defined (_IOC_SIZEBITS)
|
76 |
|
|
/* Extract the size of the ioctl data and check its bounds. */
|
77 |
|
|
# define CHECK_IOCTL(ARG, CMD) \
|
78 |
|
|
CHECK_N ((const char *) (ARG), \
|
79 |
|
|
(((CMD) >> _IOC_SIZESHIFT) & ((1 << _IOC_SIZEBITS) - 1)))
|
80 |
|
|
# else
|
81 |
|
|
/* We don't know the size of the ioctl data, so the best we can do
|
82 |
|
|
is check that the first byte is within bounds. */
|
83 |
|
|
# define CHECK_IOCTL(ARG, CMD) CHECK_1 ((const char *) ARG)
|
84 |
|
|
# endif
|
85 |
|
|
|
86 |
|
|
/* Check bounds of `struct flock *' for the locking fcntl commands. */
|
87 |
|
|
# define CHECK_FCNTL(ARG, CMD) \
|
88 |
|
|
(((CMD) == F_GETLK || (CMD) == F_SETLK || (CMD) == F_SETLKW) \
|
89 |
|
|
? CHECK_1 ((struct flock *) ARG) : (unsigned long) (ARG))
|
90 |
|
|
|
91 |
|
|
/* Check bounds of an array of mincore residency-status flags that
|
92 |
|
|
cover a region of NBYTES. Such a vector occupies one byte per page
|
93 |
|
|
of memory. */
|
94 |
|
|
# define CHECK_N_PAGES(ARG, NBYTES) \
|
95 |
|
|
({ int _page_size_ = sysconf (_SC_PAGE_SIZE); \
|
96 |
|
|
CHECK_N ((const char *) (ARG), \
|
97 |
|
|
((NBYTES) + _page_size_ - 1) / _page_size_); })
|
98 |
|
|
|
99 |
|
|
/* Return a bounded pointer with value PTR that satisfies CHECK_N (PTR, N). */
|
100 |
|
|
# define BOUNDED_N(PTR, N) \
|
101 |
|
|
({ __typeof (PTR) __bounded _p_; \
|
102 |
|
|
__ptrvalue _p_ = __ptrlow _p_ = __ptrvalue (PTR); \
|
103 |
|
|
__ptrhigh _p_ = __ptrvalue _p_ + (N); \
|
104 |
|
|
_p_; })
|
105 |
|
|
|
106 |
|
|
#else /* !__BOUNDED_POINTERS__ */
|
107 |
|
|
|
108 |
|
|
/* Do nothing if not compiling with -fbounded-pointers. */
|
109 |
|
|
|
110 |
|
|
# define BOUNDS_VIOLATED
|
111 |
|
|
# define CHECK_BOUNDS_LOW(ARG) (ARG)
|
112 |
|
|
# define CHECK_BOUNDS_HIGH(ARG) (ARG)
|
113 |
|
|
# define CHECK_1(ARG) (ARG)
|
114 |
|
|
# define CHECK_1_NULL_OK(ARG) (ARG)
|
115 |
|
|
# define CHECK_N(ARG, N) (ARG)
|
116 |
|
|
# define CHECK_N_NULL_OK(ARG, N) (ARG)
|
117 |
|
|
# define CHECK_STRING(ARG) (ARG)
|
118 |
|
|
# define CHECK_SIGSET(SET) (SET)
|
119 |
|
|
# define CHECK_SIGSET_NULL_OK(SET) (SET)
|
120 |
|
|
# define CHECK_IOCTL(ARG, CMD) (ARG)
|
121 |
|
|
# define CHECK_FCNTL(ARG, CMD) (ARG)
|
122 |
|
|
# define CHECK_N_PAGES(ARG, NBYTES) (ARG)
|
123 |
|
|
# define BOUNDED_N(PTR, N) (PTR)
|
124 |
|
|
|
125 |
|
|
#endif /* !__BOUNDED_POINTERS__ */
|
126 |
|
|
|
127 |
|
|
#define BOUNDED_1(PTR) BOUNDED_N (PTR, 1)
|
128 |
|
|
|
129 |
|
|
#endif /* _bp_checks_h_ */
|