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
|
#include <unistd.h>
#include <stdio.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <stdlib.h>
#include <linux/kernel.h>
#include "vdso.h"
#include "util.h"
#include "symbol.h"
#include "machine.h"
#include "linux/string.h"
#include "debug.h"
#define VDSO__TEMP_FILE_NAME "/tmp/perf-vdso.so-XXXXXX"
struct vdso_file {
bool found;
bool error;
char temp_file_name[sizeof(VDSO__TEMP_FILE_NAME)];
const char *dso_name;
};
struct vdso_info {
struct vdso_file vdso;
};
static struct vdso_info *vdso_info__new(void)
{
static const struct vdso_info vdso_info_init = {
.vdso = {
.temp_file_name = VDSO__TEMP_FILE_NAME,
.dso_name = DSO__NAME_VDSO,
},
};
return memdup(&vdso_info_init, sizeof(vdso_info_init));
}
static int find_vdso_map(void **start, void **end)
{
FILE *maps;
char line[128];
int found = 0;
maps = fopen("/proc/self/maps", "r");
if (!maps) {
pr_err("vdso: cannot open maps\n");
return -1;
}
while (!found && fgets(line, sizeof(line), maps)) {
int m = -1;
/* We care only about private r-x mappings. */
if (2 != sscanf(line, "%p-%p r-xp %*x %*x:%*x %*u %n",
start, end, &m))
continue;
if (m < 0)
continue;
if (!strncmp(&line[m], VDSO__MAP_NAME,
sizeof(VDSO__MAP_NAME) - 1))
found = 1;
}
fclose(maps);
return !found;
}
static char *get_file(struct vdso_file *vdso_file)
{
char *vdso = NULL;
char *buf = NULL;
void *start, *end;
size_t size;
int fd;
if (vdso_file->found)
return vdso_file->temp_file_name;
if (vdso_file->error || find_vdso_map(&start, &end))
return NULL;
size = end - start;
buf = memdup(start, size);
if (!buf)
return NULL;
fd = mkstemp(vdso_file->temp_file_name);
if (fd < 0)
goto out;
if (size == (size_t) write(fd, buf, size))
vdso = vdso_file->temp_file_name;
close(fd);
out:
free(buf);
vdso_file->found = (vdso != NULL);
vdso_file->error = !vdso_file->found;
return vdso;
}
void vdso__exit(struct machine *machine)
{
struct vdso_info *vdso_info = machine->vdso_info;
if (!vdso_info)
return;
if (vdso_info->vdso.found)
unlink(vdso_info->vdso.temp_file_name);
zfree(&machine->vdso_info);
}
static struct dso *vdso__new(struct machine *machine, const char *short_name,
const char *long_name)
{
struct dso *dso;
dso = dso__new(short_name);
if (dso != NULL) {
dsos__add(&machine->user_dsos, dso);
dso__set_long_name(dso, long_name, false);
}
return dso;
}
struct dso *vdso__dso_findnew(struct machine *machine,
struct thread *thread __maybe_unused)
{
struct vdso_info *vdso_info;
struct dso *dso;
if (!machine->vdso_info)
machine->vdso_info = vdso_info__new();
vdso_info = machine->vdso_info;
if (!vdso_info)
return NULL;
dso = dsos__find(&machine->user_dsos, DSO__NAME_VDSO, true);
if (!dso) {
char *file;
file = get_file(&vdso_info->vdso);
if (!file)
return NULL;
dso = vdso__new(machine, DSO__NAME_VDSO, file);
}
return dso;
}
bool dso__is_vdso(struct dso *dso)
{
return !strcmp(dso->short_name, DSO__NAME_VDSO);
}
|
