Loading...
1#include <linux/compiler.h>
2#include <linux/rbtree.h>
3#include <string.h>
4#include "map.h"
5#include "symbol.h"
6#include "util.h"
7#include "tests.h"
8#include "debug.h"
9#include "machine.h"
10
11static int vmlinux_matches_kallsyms_filter(struct map *map __maybe_unused,
12 struct symbol *sym)
13{
14 bool *visited = symbol__priv(sym);
15 *visited = true;
16 return 0;
17}
18
19#define UM(x) kallsyms_map->unmap_ip(kallsyms_map, (x))
20
21int test__vmlinux_matches_kallsyms(void)
22{
23 int err = -1;
24 struct rb_node *nd;
25 struct symbol *sym;
26 struct map *kallsyms_map, *vmlinux_map;
27 struct machine kallsyms, vmlinux;
28 enum map_type type = MAP__FUNCTION;
29 u64 mem_start, mem_end;
30
31 /*
32 * Step 1:
33 *
34 * Init the machines that will hold kernel, modules obtained from
35 * both vmlinux + .ko files and from /proc/kallsyms split by modules.
36 */
37 machine__init(&kallsyms, "", HOST_KERNEL_ID);
38 machine__init(&vmlinux, "", HOST_KERNEL_ID);
39
40 /*
41 * Step 2:
42 *
43 * Create the kernel maps for kallsyms and the DSO where we will then
44 * load /proc/kallsyms. Also create the modules maps from /proc/modules
45 * and find the .ko files that match them in /lib/modules/`uname -r`/.
46 */
47 if (machine__create_kernel_maps(&kallsyms) < 0) {
48 pr_debug("machine__create_kernel_maps ");
49 goto out;
50 }
51
52 /*
53 * Step 3:
54 *
55 * Load and split /proc/kallsyms into multiple maps, one per module.
56 */
57 if (machine__load_kallsyms(&kallsyms, "/proc/kallsyms", type, NULL) <= 0) {
58 pr_debug("dso__load_kallsyms ");
59 goto out;
60 }
61
62 /*
63 * Step 4:
64 *
65 * kallsyms will be internally on demand sorted by name so that we can
66 * find the reference relocation * symbol, i.e. the symbol we will use
67 * to see if the running kernel was relocated by checking if it has the
68 * same value in the vmlinux file we load.
69 */
70 kallsyms_map = machine__kernel_map(&kallsyms, type);
71
72 /*
73 * Step 5:
74 *
75 * Now repeat step 2, this time for the vmlinux file we'll auto-locate.
76 */
77 if (machine__create_kernel_maps(&vmlinux) < 0) {
78 pr_debug("machine__create_kernel_maps ");
79 goto out;
80 }
81
82 vmlinux_map = machine__kernel_map(&vmlinux, type);
83
84 /*
85 * Step 6:
86 *
87 * Locate a vmlinux file in the vmlinux path that has a buildid that
88 * matches the one of the running kernel.
89 *
90 * While doing that look if we find the ref reloc symbol, if we find it
91 * we'll have its ref_reloc_symbol.unrelocated_addr and then
92 * maps__reloc_vmlinux will notice and set proper ->[un]map_ip routines
93 * to fixup the symbols.
94 */
95 if (machine__load_vmlinux_path(&vmlinux, type,
96 vmlinux_matches_kallsyms_filter) <= 0) {
97 pr_debug("Couldn't find a vmlinux that matches the kernel running on this machine, skipping test\n");
98 err = TEST_SKIP;
99 goto out;
100 }
101
102 err = 0;
103 /*
104 * Step 7:
105 *
106 * Now look at the symbols in the vmlinux DSO and check if we find all of them
107 * in the kallsyms dso. For the ones that are in both, check its names and
108 * end addresses too.
109 */
110 for (nd = rb_first(&vmlinux_map->dso->symbols[type]); nd; nd = rb_next(nd)) {
111 struct symbol *pair, *first_pair;
112 bool backwards = true;
113
114 sym = rb_entry(nd, struct symbol, rb_node);
115
116 if (sym->start == sym->end)
117 continue;
118
119 mem_start = vmlinux_map->unmap_ip(vmlinux_map, sym->start);
120 mem_end = vmlinux_map->unmap_ip(vmlinux_map, sym->end);
121
122 first_pair = machine__find_kernel_symbol(&kallsyms, type,
123 mem_start, NULL, NULL);
124 pair = first_pair;
125
126 if (pair && UM(pair->start) == mem_start) {
127next_pair:
128 if (strcmp(sym->name, pair->name) == 0) {
129 /*
130 * kallsyms don't have the symbol end, so we
131 * set that by using the next symbol start - 1,
132 * in some cases we get this up to a page
133 * wrong, trace_kmalloc when I was developing
134 * this code was one such example, 2106 bytes
135 * off the real size. More than that and we
136 * _really_ have a problem.
137 */
138 s64 skew = mem_end - UM(pair->end);
139 if (llabs(skew) >= page_size)
140 pr_debug("%#" PRIx64 ": diff end addr for %s v: %#" PRIx64 " k: %#" PRIx64 "\n",
141 mem_start, sym->name, mem_end,
142 UM(pair->end));
143
144 /*
145 * Do not count this as a failure, because we
146 * could really find a case where it's not
147 * possible to get proper function end from
148 * kallsyms.
149 */
150 continue;
151
152 } else {
153 struct rb_node *nnd;
154detour:
155 nnd = backwards ? rb_prev(&pair->rb_node) :
156 rb_next(&pair->rb_node);
157 if (nnd) {
158 struct symbol *next = rb_entry(nnd, struct symbol, rb_node);
159
160 if (UM(next->start) == mem_start) {
161 pair = next;
162 goto next_pair;
163 }
164 }
165
166 if (backwards) {
167 backwards = false;
168 pair = first_pair;
169 goto detour;
170 }
171
172 pr_debug("%#" PRIx64 ": diff name v: %s k: %s\n",
173 mem_start, sym->name, pair->name);
174 }
175 } else
176 pr_debug("%#" PRIx64 ": %s not on kallsyms\n",
177 mem_start, sym->name);
178
179 err = -1;
180 }
181
182 if (!verbose)
183 goto out;
184
185 pr_info("Maps only in vmlinux:\n");
186
187 for (nd = rb_first(&vmlinux.kmaps.maps[type]); nd; nd = rb_next(nd)) {
188 struct map *pos = rb_entry(nd, struct map, rb_node), *pair;
189 /*
190 * If it is the kernel, kallsyms is always "[kernel.kallsyms]", while
191 * the kernel will have the path for the vmlinux file being used,
192 * so use the short name, less descriptive but the same ("[kernel]" in
193 * both cases.
194 */
195 pair = map_groups__find_by_name(&kallsyms.kmaps, type,
196 (pos->dso->kernel ?
197 pos->dso->short_name :
198 pos->dso->name));
199 if (pair)
200 pair->priv = 1;
201 else
202 map__fprintf(pos, stderr);
203 }
204
205 pr_info("Maps in vmlinux with a different name in kallsyms:\n");
206
207 for (nd = rb_first(&vmlinux.kmaps.maps[type]); nd; nd = rb_next(nd)) {
208 struct map *pos = rb_entry(nd, struct map, rb_node), *pair;
209
210 mem_start = vmlinux_map->unmap_ip(vmlinux_map, pos->start);
211 mem_end = vmlinux_map->unmap_ip(vmlinux_map, pos->end);
212
213 pair = map_groups__find(&kallsyms.kmaps, type, mem_start);
214 if (pair == NULL || pair->priv)
215 continue;
216
217 if (pair->start == mem_start) {
218 pair->priv = 1;
219 pr_info(" %" PRIx64 "-%" PRIx64 " %" PRIx64 " %s in kallsyms as",
220 pos->start, pos->end, pos->pgoff, pos->dso->name);
221 if (mem_end != pair->end)
222 pr_info(":\n*%" PRIx64 "-%" PRIx64 " %" PRIx64,
223 pair->start, pair->end, pair->pgoff);
224 pr_info(" %s\n", pair->dso->name);
225 pair->priv = 1;
226 }
227 }
228
229 pr_info("Maps only in kallsyms:\n");
230
231 for (nd = rb_first(&kallsyms.kmaps.maps[type]);
232 nd; nd = rb_next(nd)) {
233 struct map *pos = rb_entry(nd, struct map, rb_node);
234
235 if (!pos->priv)
236 map__fprintf(pos, stderr);
237 }
238out:
239 machine__exit(&kallsyms);
240 machine__exit(&vmlinux);
241 return err;
242}
1// SPDX-License-Identifier: GPL-2.0
2#include <linux/compiler.h>
3#include <linux/rbtree.h>
4#include <inttypes.h>
5#include <string.h>
6#include "map.h"
7#include "symbol.h"
8#include "util.h"
9#include "tests.h"
10#include "debug.h"
11#include "machine.h"
12
13#define UM(x) kallsyms_map->unmap_ip(kallsyms_map, (x))
14
15int test__vmlinux_matches_kallsyms(struct test *test __maybe_unused, int subtest __maybe_unused)
16{
17 int err = -1;
18 struct rb_node *nd;
19 struct symbol *sym;
20 struct map *kallsyms_map, *vmlinux_map, *map;
21 struct machine kallsyms, vmlinux;
22 enum map_type type = MAP__FUNCTION;
23 struct maps *maps = &vmlinux.kmaps.maps[type];
24 u64 mem_start, mem_end;
25 bool header_printed;
26
27 /*
28 * Step 1:
29 *
30 * Init the machines that will hold kernel, modules obtained from
31 * both vmlinux + .ko files and from /proc/kallsyms split by modules.
32 */
33 machine__init(&kallsyms, "", HOST_KERNEL_ID);
34 machine__init(&vmlinux, "", HOST_KERNEL_ID);
35
36 /*
37 * Step 2:
38 *
39 * Create the kernel maps for kallsyms and the DSO where we will then
40 * load /proc/kallsyms. Also create the modules maps from /proc/modules
41 * and find the .ko files that match them in /lib/modules/`uname -r`/.
42 */
43 if (machine__create_kernel_maps(&kallsyms) < 0) {
44 pr_debug("machine__create_kernel_maps ");
45 goto out;
46 }
47
48 /*
49 * Step 3:
50 *
51 * Load and split /proc/kallsyms into multiple maps, one per module.
52 * Do not use kcore, as this test was designed before kcore support
53 * and has parts that only make sense if using the non-kcore code.
54 * XXX: extend it to stress the kcorre code as well, hint: the list
55 * of modules extracted from /proc/kcore, in its current form, can't
56 * be compacted against the list of modules found in the "vmlinux"
57 * code and with the one got from /proc/modules from the "kallsyms" code.
58 */
59 if (machine__load_kallsyms(&kallsyms, "/proc/kallsyms", type) <= 0) {
60 pr_debug("dso__load_kallsyms ");
61 goto out;
62 }
63
64 /*
65 * Step 4:
66 *
67 * kallsyms will be internally on demand sorted by name so that we can
68 * find the reference relocation * symbol, i.e. the symbol we will use
69 * to see if the running kernel was relocated by checking if it has the
70 * same value in the vmlinux file we load.
71 */
72 kallsyms_map = machine__kernel_map(&kallsyms);
73
74 /*
75 * Step 5:
76 *
77 * Now repeat step 2, this time for the vmlinux file we'll auto-locate.
78 */
79 if (machine__create_kernel_maps(&vmlinux) < 0) {
80 pr_debug("machine__create_kernel_maps ");
81 goto out;
82 }
83
84 vmlinux_map = machine__kernel_map(&vmlinux);
85
86 /*
87 * Step 6:
88 *
89 * Locate a vmlinux file in the vmlinux path that has a buildid that
90 * matches the one of the running kernel.
91 *
92 * While doing that look if we find the ref reloc symbol, if we find it
93 * we'll have its ref_reloc_symbol.unrelocated_addr and then
94 * maps__reloc_vmlinux will notice and set proper ->[un]map_ip routines
95 * to fixup the symbols.
96 */
97 if (machine__load_vmlinux_path(&vmlinux, type) <= 0) {
98 pr_debug("Couldn't find a vmlinux that matches the kernel running on this machine, skipping test\n");
99 err = TEST_SKIP;
100 goto out;
101 }
102
103 err = 0;
104 /*
105 * Step 7:
106 *
107 * Now look at the symbols in the vmlinux DSO and check if we find all of them
108 * in the kallsyms dso. For the ones that are in both, check its names and
109 * end addresses too.
110 */
111 for (nd = rb_first(&vmlinux_map->dso->symbols[type]); nd; nd = rb_next(nd)) {
112 struct symbol *pair, *first_pair;
113
114 sym = rb_entry(nd, struct symbol, rb_node);
115
116 if (sym->start == sym->end)
117 continue;
118
119 mem_start = vmlinux_map->unmap_ip(vmlinux_map, sym->start);
120 mem_end = vmlinux_map->unmap_ip(vmlinux_map, sym->end);
121
122 first_pair = machine__find_kernel_symbol(&kallsyms, type,
123 mem_start, NULL);
124 pair = first_pair;
125
126 if (pair && UM(pair->start) == mem_start) {
127next_pair:
128 if (arch__compare_symbol_names(sym->name, pair->name) == 0) {
129 /*
130 * kallsyms don't have the symbol end, so we
131 * set that by using the next symbol start - 1,
132 * in some cases we get this up to a page
133 * wrong, trace_kmalloc when I was developing
134 * this code was one such example, 2106 bytes
135 * off the real size. More than that and we
136 * _really_ have a problem.
137 */
138 s64 skew = mem_end - UM(pair->end);
139 if (llabs(skew) >= page_size)
140 pr_debug("WARN: %#" PRIx64 ": diff end addr for %s v: %#" PRIx64 " k: %#" PRIx64 "\n",
141 mem_start, sym->name, mem_end,
142 UM(pair->end));
143
144 /*
145 * Do not count this as a failure, because we
146 * could really find a case where it's not
147 * possible to get proper function end from
148 * kallsyms.
149 */
150 continue;
151 } else {
152 pair = machine__find_kernel_symbol_by_name(&kallsyms, type, sym->name, NULL);
153 if (pair) {
154 if (UM(pair->start) == mem_start)
155 goto next_pair;
156
157 pr_debug("WARN: %#" PRIx64 ": diff name v: %s k: %s\n",
158 mem_start, sym->name, pair->name);
159 } else {
160 pr_debug("WARN: %#" PRIx64 ": diff name v: %s k: %s\n",
161 mem_start, sym->name, first_pair->name);
162 }
163
164 continue;
165 }
166 } else
167 pr_debug("ERR : %#" PRIx64 ": %s not on kallsyms\n",
168 mem_start, sym->name);
169
170 err = -1;
171 }
172
173 if (verbose <= 0)
174 goto out;
175
176 header_printed = false;
177
178 for (map = maps__first(maps); map; map = map__next(map)) {
179 struct map *
180 /*
181 * If it is the kernel, kallsyms is always "[kernel.kallsyms]", while
182 * the kernel will have the path for the vmlinux file being used,
183 * so use the short name, less descriptive but the same ("[kernel]" in
184 * both cases.
185 */
186 pair = map_groups__find_by_name(&kallsyms.kmaps, type,
187 (map->dso->kernel ?
188 map->dso->short_name :
189 map->dso->name));
190 if (pair) {
191 pair->priv = 1;
192 } else {
193 if (!header_printed) {
194 pr_info("WARN: Maps only in vmlinux:\n");
195 header_printed = true;
196 }
197 map__fprintf(map, stderr);
198 }
199 }
200
201 header_printed = false;
202
203 for (map = maps__first(maps); map; map = map__next(map)) {
204 struct map *pair;
205
206 mem_start = vmlinux_map->unmap_ip(vmlinux_map, map->start);
207 mem_end = vmlinux_map->unmap_ip(vmlinux_map, map->end);
208
209 pair = map_groups__find(&kallsyms.kmaps, type, mem_start);
210 if (pair == NULL || pair->priv)
211 continue;
212
213 if (pair->start == mem_start) {
214 if (!header_printed) {
215 pr_info("WARN: Maps in vmlinux with a different name in kallsyms:\n");
216 header_printed = true;
217 }
218
219 pr_info("WARN: %" PRIx64 "-%" PRIx64 " %" PRIx64 " %s in kallsyms as",
220 map->start, map->end, map->pgoff, map->dso->name);
221 if (mem_end != pair->end)
222 pr_info(":\nWARN: *%" PRIx64 "-%" PRIx64 " %" PRIx64,
223 pair->start, pair->end, pair->pgoff);
224 pr_info(" %s\n", pair->dso->name);
225 pair->priv = 1;
226 }
227 }
228
229 header_printed = false;
230
231 maps = &kallsyms.kmaps.maps[type];
232
233 for (map = maps__first(maps); map; map = map__next(map)) {
234 if (!map->priv) {
235 if (!header_printed) {
236 pr_info("WARN: Maps only in kallsyms:\n");
237 header_printed = true;
238 }
239 map__fprintf(map, stderr);
240 }
241 }
242out:
243 machine__exit(&kallsyms);
244 machine__exit(&vmlinux);
245 return err;
246}