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
|
/* Dynamic linker system dependencies for Linux.
Copyright (C) 1995-2018 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/>. */
/* Linux needs some special initialization, but otherwise uses
the generic dynamic linker system interface code. */
#include <string.h>
#include <fcntl.h>
#include <unistd.h>
#include <sys/param.h>
#include <sys/utsname.h>
#include <ldsodefs.h>
#include <not-cancel.h>
#ifdef SHARED
# define DL_SYSDEP_INIT frob_brk ()
static inline void
frob_brk (void)
{
__brk (0); /* Initialize the break. */
}
# include <elf/dl-sysdep.c>
#endif
int
attribute_hidden
_dl_discover_osversion (void)
{
#if 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(Nhdr) hdr;
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 ElfW(Nhdr) *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 note->n_type - 1) & -sizeof note->n_type)
note = ((const void *) (note + 1)
+ ROUND (note->n_namesz) + ROUND (note->n_descsz));
#undef ROUND
}
}
}
#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 = __open64_nocancel ("/proc/sys/kernel/osrelease", O_RDONLY);
if (fd < 0)
return -1;
ssize_t reslen = __read_nocancel (fd, bufmem, sizeof (bufmem));
__close_nocancel (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++ != '.' || parts == 3)
/* Another part following? */
break;
}
if (parts < 3)
version <<= 8 * (3 - parts);
return version;
}
|
