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
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
|
/* Operating system specific code for generic dynamic loader functions. Linux.
Copyright (C) 2000,2001,2002,2004,2005,2006 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, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
#include <string.h>
#include <errno.h>
#include <fcntl.h>
#include <sys/utsname.h>
#include <kernel-features.h>
#include <dl-sysdep.h>
#include <stdint.h>
#include <hp-timing.h>
#include <endian.h>
#ifndef MIN
# define MIN(a,b) (((a)<(b))?(a):(b))
#endif
#ifdef SHARED
/* This is the function used in the dynamic linker to print the fatal error
message. */
static inline void
__attribute__ ((__noreturn__))
dl_fatal (const char *str)
{
_dl_dprintf (2, str);
_exit (1);
}
#endif
static inline int __attribute__ ((always_inline))
_dl_discover_osversion (void)
{
#if (defined NEED_DL_SYSINFO || defined NEED_DL_SYSINFO_DSO) && defined SHARED
if (GLRO(dl_sysinfo_map) != NULL)
{
/* If the kernel-supplied DSO contains a note indicating the kernel's
version, we don't need to call uname or parse any strings. */
static const struct
{
ElfW(Word) vendorlen;
ElfW(Word) datalen;
ElfW(Word) type;
char vendor[8];
} expected_note = { sizeof "Linux", sizeof (ElfW(Word)), 0, "Linux" };
const ElfW(Phdr) *const phdr = GLRO(dl_sysinfo_map)->l_phdr;
const ElfW(Word) phnum = GLRO(dl_sysinfo_map)->l_phnum;
for (uint_fast16_t i = 0; i < phnum; ++i)
if (phdr[i].p_type == PT_NOTE)
{
const ElfW(Addr) start = (phdr[i].p_vaddr
+ GLRO(dl_sysinfo_map)->l_addr);
const struct
{
ElfW(Word) vendorlen;
ElfW(Word) datalen;
ElfW(Word) type;
} *note = (const void *) start;
while ((ElfW(Addr)) (note + 1) - start < phdr[i].p_memsz)
{
if (!memcmp (note, &expected_note, sizeof expected_note))
return *(const ElfW(Word) *) ((const void *) note
+ sizeof expected_note);
#define ROUND(len) (((len) + sizeof (ElfW(Word)) - 1) & -sizeof (ElfW(Word)))
note = ((const void *) (note + 1)
+ ROUND (note->vendorlen) + ROUND (note->datalen));
}
}
}
#endif
char bufmem[64];
char *buf = bufmem;
unsigned int version;
int parts;
char *cp;
struct utsname uts;
/* Try the uname system call. */
if (__uname (&uts))
{
/* This was not successful. Now try reading the /proc filesystem. */
int fd = __open ("/proc/sys/kernel/osrelease", O_RDONLY);
if (fd < 0)
return -1;
ssize_t reslen = __read (fd, bufmem, sizeof (bufmem));
__close (fd);
if (reslen <= 0)
/* This also didn't work. We give up since we cannot
make sure the library can actually work. */
return -1;
buf[MIN (reslen, (ssize_t) sizeof (bufmem) - 1)] = '\0';
}
else
buf = uts.release;
/* Now convert it into a number. The string consists of at most
three parts. */
version = 0;
parts = 0;
cp = buf;
while ((*cp >= '0') && (*cp <= '9'))
{
unsigned int here = *cp++ - '0';
while ((*cp >= '0') && (*cp <= '9'))
{
here *= 10;
here += *cp++ - '0';
}
++parts;
version <<= 8;
version |= here;
if (*cp++ != '.')
/* Another part following? */
break;
}
if (parts < 3)
version <<= 8 * (3 - parts);
return version;
}
#define DL_SYSDEP_OSCHECK(FATAL) \
do { \
/* Test whether the kernel is new enough. This test is only performed \
if the library is not compiled to run on all kernels. */ \
\
int version = _dl_discover_osversion (); \
if (__builtin_expect (version >= 0, 1)) \
{ \
if (__builtin_expect (GLRO(dl_osversion) == 0, 1) \
|| GLRO(dl_osversion) > version) \
GLRO(dl_osversion) = version; \
\
/* Now we can test with the required version. */ \
if (__LINUX_KERNEL_VERSION > 0 && version < __LINUX_KERNEL_VERSION) \
/* Not sufficent. */ \
FATAL ("FATAL: kernel too old\n"); \
} \
else if (__LINUX_KERNEL_VERSION > 0) \
FATAL ("FATAL: cannot determine kernel version\n"); \
} while (0)
static inline uintptr_t __attribute__ ((always_inline))
_dl_setup_stack_chk_guard (void)
{
uintptr_t ret;
#ifdef ENABLE_STACKGUARD_RANDOMIZE
int fd = __open ("/dev/urandom", O_RDONLY);
if (fd >= 0)
{
ssize_t reslen = __read (fd, &ret, sizeof (ret));
__close (fd);
if (reslen == (ssize_t) sizeof (ret))
return ret;
}
#endif
ret = 0;
unsigned char *p = (unsigned char *) &ret;
p[sizeof (ret) - 1] = 255;
p[sizeof (ret) - 2] = '\n';
#ifdef HP_TIMING_NOW
hp_timing_t hpt;
HP_TIMING_NOW (hpt);
hpt = (hpt & 0xffff) << 8;
ret ^= hpt;
#endif
uintptr_t stk;
/* Avoid GCC being too smart. */
asm ("" : "=r" (stk) : "r" (p));
stk &= 0x7ffff0;
#if __BYTE_ORDER == __LITTLE_ENDIAN
stk <<= (__WORDSIZE - 23);
#elif __WORDSIZE == 64
stk <<= 31;
#endif
ret ^= stk;
/* Avoid GCC being too smart. */
p = (unsigned char *) &errno;
asm ("" : "=r" (stk) : "r" (p));
stk &= 0x7fff00;
#if __BYTE_ORDER == __LITTLE_ENDIAN
stk <<= (__WORDSIZE - 29);
#else
stk >>= 8;
#endif
ret ^= stk;
return ret;
}
|
