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
|
// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
/* Copyright (c) 2025 Isovalent */
#include <test_progs.h>
#include <bpf/btf.h>
#include <dirent.h>
#include <limits.h>
#include <sys/stat.h>
#include <sys/mman.h>
#include <fcntl.h>
#include <unistd.h>
#define BTF_SYSFS_DIR "/sys/kernel/btf"
#define BTF_INLINE_SUFFIX ".inline"
static void test_btf_mmap_sysfs(const char *path, struct btf *base)
{
struct stat st;
__u64 btf_size, end;
size_t mmap_len = 0;
void *raw_data = NULL;
int fd = -1;
long page_size;
struct btf *btf = NULL;
page_size = sysconf(_SC_PAGESIZE);
if (!ASSERT_GE(page_size, 0, "get_page_size"))
goto cleanup;
if (!ASSERT_OK(stat(path, &st), "stat_btf"))
goto cleanup;
btf_size = st.st_size;
end = (btf_size + page_size - 1) / page_size * page_size;
mmap_len = btf_size;
fd = open(path, O_RDONLY);
if (!ASSERT_GE(fd, 0, "open_btf"))
goto cleanup;
raw_data = mmap(NULL, btf_size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
if (!ASSERT_EQ(raw_data, MAP_FAILED, "mmap_btf_writable"))
goto cleanup;
raw_data = mmap(NULL, btf_size, PROT_READ, MAP_SHARED, fd, 0);
if (!ASSERT_EQ(raw_data, MAP_FAILED, "mmap_btf_shared"))
goto cleanup;
mmap_len = end + 1;
raw_data = mmap(NULL, mmap_len, PROT_READ, MAP_PRIVATE, fd, 0);
if (!ASSERT_EQ(raw_data, MAP_FAILED, "mmap_btf_invalid_size"))
goto cleanup;
mmap_len = end;
raw_data = mmap(NULL, mmap_len, PROT_READ, MAP_PRIVATE, fd, 0);
if (!ASSERT_OK_PTR(raw_data, "mmap_btf"))
goto cleanup;
if (!ASSERT_EQ(mprotect(raw_data, btf_size, PROT_READ | PROT_WRITE), -1,
"mprotect_writable"))
goto cleanup;
if (!ASSERT_EQ(mprotect(raw_data, btf_size, PROT_READ | PROT_EXEC), -1,
"mprotect_executable"))
goto cleanup;
/* Check padding is zeroed */
for (int i = btf_size; i < end; i++) {
if (((__u8 *)raw_data)[i] != 0) {
PRINT_FAIL("tail of BTF is not zero at page offset %d\n", i);
goto cleanup;
}
}
btf = btf__new_split(raw_data, btf_size, base);
if (!ASSERT_OK_PTR(btf, "parse_btf"))
goto cleanup;
cleanup:
btf__free(btf);
if (raw_data && raw_data != MAP_FAILED)
munmap(raw_data, mmap_len);
if (fd >= 0)
close(fd);
}
static void test_btf_inline_sysfs_all(void)
{
struct btf *vmlinux_btf;
struct dirent *dentry;
DIR *dir;
int err = 0;
dir = opendir(BTF_SYSFS_DIR);
if (!ASSERT_OK_PTR(dir, "open_btf_sysfs"))
return;
vmlinux_btf = btf__parse(BTF_SYSFS_DIR "/vmlinux", NULL);
if (!ASSERT_OK_PTR(vmlinux_btf, "parse_vmlinux_btf")) {
closedir(dir);
return;
}
while ((dentry = readdir(dir)) != NULL) {
struct btf *base_btf = NULL, *module_btf = NULL, *inline_btf = NULL;
char btf_path[PATH_MAX], inline_path[PATH_MAX];
struct stat st;
/* Skip ".", ".." and "foo.inline" */
if (strstr(dentry->d_name, "."))
continue;
if (strcmp(dentry->d_name, "vmlinux") == 0)
base_btf = vmlinux_btf;
if (snprintf(btf_path, sizeof(btf_path), "%s/%s",
BTF_SYSFS_DIR, dentry->d_name) >= sizeof(btf_path) ||
snprintf(inline_path, sizeof(inline_path), "%s/%s%s",
BTF_SYSFS_DIR, dentry->d_name, BTF_INLINE_SUFFIX) >=
sizeof(inline_path)) {
ASSERT_FAIL("BTF sysfs path is too long\n");
break;
}
if (!base_btf) {
module_btf = btf__parse_split(btf_path, vmlinux_btf);
err = libbpf_get_error(module_btf);
if (err) {
/* A module can be unloaded while its sysfs entry is iterated. */
if (err == -ENOENT)
continue;
ASSERT_OK(err, "parse_module_btf");
continue;
}
base_btf = module_btf;
}
if (stat(inline_path, &st)) {
err = errno;
if (err != ENOENT)
ASSERT_OK(err, "stat_inline_btf");
btf__free(module_btf);
continue;
}
if (base_btf == vmlinux_btf)
test_btf_mmap_sysfs(inline_path, base_btf);
inline_btf = btf__parse_split(inline_path, base_btf);
err = libbpf_get_error(inline_btf);
if (!err)
btf__free(inline_btf);
ASSERT_OK(err, "parse_inline_btf");
btf__free(module_btf);
}
closedir(dir);
btf__free(vmlinux_btf);
}
void test_btf_sysfs(void)
{
test_btf_mmap_sysfs("/sys/kernel/btf/vmlinux", NULL);
test_btf_inline_sysfs_all();
}
|
