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1// SPDX-License-Identifier: GPL-2.0
2#include <linux/compiler.h>
3#include <fcntl.h>
4#include <signal.h>
5#include <unistd.h>
6#include <sys/stat.h>
7#include "util/dso.h"
8#include "util/map.h"
9#include "util/symbol.h"
10#include "util/debug.h"
11#include "util/machine.h"
12#include "tests.h"
13
14/*
15 * This test is to check whether a bad symbol in a module won't split kallsyms maps.
16 * The main_symbol[1-3] should belong to the main [kernel.kallsyms] map even if the
17 * bad_symbol from the module is found in the middle.
18 */
19static char root_template[] = "/tmp/perf-test.XXXXXX";
20static char *root_dir;
21
22static const char proc_version[] = "Linux version X.Y.Z (just for perf test)\n";
23static const char proc_modules[] = "module 4096 1 - Live 0xffffffffcd000000\n";
24static const char proc_kallsyms[] =
25 "ffffffffab200000 T _stext\n"
26 "ffffffffab200010 T good_symbol\n"
27 "ffffffffab200020 t bad_symbol\n"
28 "ffffffffab200030 t main_symbol1\n"
29 "ffffffffab200040 t main_symbol2\n"
30 "ffffffffab200050 t main_symbol3\n"
31 "ffffffffab200060 T _etext\n"
32 "ffffffffcd000000 T start_module\t[module]\n"
33 "ffffffffab200020 u bad_symbol\t[module]\n"
34 "ffffffffcd000040 T end_module\t[module]\n";
35
36static struct {
37 const char *name;
38 const char *contents;
39 long len;
40} proc_files[] = {
41 { "version", proc_version, sizeof(proc_version) - 1 },
42 { "modules", proc_modules, sizeof(proc_modules) - 1 },
43 { "kallsyms", proc_kallsyms, sizeof(proc_kallsyms) - 1 },
44};
45
46static void remove_proc_dir(int sig __maybe_unused)
47{
48 char buf[128];
49
50 if (root_dir == NULL)
51 return;
52
53 for (unsigned i = 0; i < ARRAY_SIZE(proc_files); i++) {
54 scnprintf(buf, sizeof(buf), "%s/proc/%s", root_dir, proc_files[i].name);
55 remove(buf);
56 }
57
58 scnprintf(buf, sizeof(buf), "%s/proc", root_dir);
59 rmdir(buf);
60
61 rmdir(root_dir);
62 root_dir = NULL;
63}
64
65static int create_proc_dir(void)
66{
67 char buf[128];
68
69 root_dir = mkdtemp(root_template);
70 if (root_dir == NULL)
71 return -1;
72
73 scnprintf(buf, sizeof(buf), "%s/proc", root_dir);
74 if (mkdir(buf, 0700) < 0)
75 goto err;
76
77 for (unsigned i = 0; i < ARRAY_SIZE(proc_files); i++) {
78 int fd, len;
79
80 scnprintf(buf, sizeof(buf), "%s/proc/%s", root_dir, proc_files[i].name);
81 fd = open(buf, O_RDWR | O_CREAT, 0600);
82 if (fd < 0)
83 goto err;
84
85 len = write(fd, proc_files[i].contents, proc_files[i].len);
86 close(fd);
87 if (len != proc_files[i].len)
88 goto err;
89 }
90 return 0;
91
92err:
93 remove_proc_dir(0);
94 return -1;
95}
96
97static int test__kallsyms_split(struct test_suite *test __maybe_unused,
98 int subtest __maybe_unused)
99{
100 struct machine m = { 0 };
101 struct map *map = NULL;
102 int ret = TEST_FAIL;
103
104 pr_debug("try to create fake root directory\n");
105 if (create_proc_dir() < 0) {
106 pr_debug("SKIP: cannot create a fake root directory\n");
107 return TEST_SKIP;
108 }
109
110 signal(SIGINT, remove_proc_dir);
111 signal(SIGPIPE, remove_proc_dir);
112 signal(SIGSEGV, remove_proc_dir);
113 signal(SIGTERM, remove_proc_dir);
114
115 pr_debug("create kernel maps from the fake root directory\n");
116 if (machine__init(&m, root_dir, HOST_KERNEL_ID)) {
117 pr_debug("FAIL: failed to init machine\n");
118 goto out;
119 }
120 if (machine__create_kernel_maps(&m) < 0) {
121 pr_debug("FAIL: failed to create kernel maps\n");
122 goto out;
123 }
124
125 /* force to use /proc/kallsyms */
126 symbol_conf.ignore_vmlinux = true;
127 symbol_conf.ignore_vmlinux_buildid = true;
128 symbol_conf.allow_aliases = true;
129
130 if (map__load(machine__kernel_map(&m)) < 0) {
131 pr_debug("FAIL: failed to load kallsyms\n");
132 goto out;
133 }
134
135 pr_debug("kernel map loaded - check symbol and map\n");
136 if (maps__nr_maps(machine__kernel_maps(&m)) != 2) {
137 pr_debug("FAIL: it should have the kernel and a module, but has %u maps\n",
138 maps__nr_maps(machine__kernel_maps(&m)));
139 goto out;
140 }
141
142 if (machine__find_kernel_symbol_by_name(&m, "main_symbol3", &map) == NULL) {
143 pr_debug("FAIL: failed to find a symbol\n");
144 goto out;
145 }
146
147 if (!RC_CHK_EQUAL(map, machine__kernel_map(&m))) {
148 pr_debug("FAIL: the symbol is not in the kernel map\n");
149 goto out;
150 }
151 ret = TEST_OK;
152
153out:
154 map__put(map);
155 remove_proc_dir(0);
156 machine__exit(&m);
157 return ret;
158}
159
160DEFINE_SUITE("split kallsyms", kallsyms_split);