1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/compiler.h>
3 #include <linux/rbtree.h>
11 #include <internal/lib.h> // page_size
16 #define UM(x) map__unmap_ip(kallsyms_map, (x))
18 static bool is_ignored_symbol(const char *name, char type)
20 /* Symbol names that exactly match to the following are ignored.*/
21 static const char * const ignored_symbols[] = {
23 * Symbols which vary between passes. Passes 1 and 2 must have
24 * identical symbol lists. The kallsyms_* symbols below are
25 * only added after pass 1, they would be included in pass 2
26 * when --all-symbols is specified so exclude them to get a
31 "kallsyms_relative_base",
35 "kallsyms_token_table",
36 "kallsyms_token_index",
37 /* Exclude linker generated symbols which vary between passes */
38 "_SDA_BASE_", /* ppc */
39 "_SDA2_BASE_", /* ppc */
43 /* Symbol names that begin with the following are ignored.*/
44 static const char * const ignored_prefixes[] = {
45 "$", /* local symbols for ARM, MIPS, etc. */
46 ".L", /* local labels, .LBB,.Ltmpxxx,.L__unnamed_xx,.LASANPC, etc. */
47 "__crc_", /* modversions */
48 "__efistub_", /* arm64 EFI stub namespace */
49 "__kvm_nvhe_$", /* arm64 local symbols in non-VHE KVM namespace */
50 "__kvm_nvhe_.L", /* arm64 local symbols in non-VHE KVM namespace */
51 "__AArch64ADRPThunk_", /* arm64 lld */
52 "__ARMV5PILongThunk_", /* arm lld */
53 "__ARMV7PILongThunk_",
54 "__ThumbV7PILongThunk_",
55 "__LA25Thunk_", /* mips lld */
60 /* Symbol names that end with the following are ignored.*/
61 static const char * const ignored_suffixes[] = {
62 "_from_arm", /* arm */
63 "_from_thumb", /* arm */
68 /* Symbol names that contain the following are ignored.*/
69 static const char * const ignored_matches[] = {
70 ".long_branch.", /* ppc stub */
71 ".plt_branch.", /* ppc stub */
75 const char * const *p;
77 for (p = ignored_symbols; *p; p++)
78 if (!strcmp(name, *p))
81 for (p = ignored_prefixes; *p; p++)
82 if (!strncmp(name, *p, strlen(*p)))
85 for (p = ignored_suffixes; *p; p++) {
86 int l = strlen(name) - strlen(*p);
88 if (l >= 0 && !strcmp(name + l, *p))
92 for (p = ignored_matches; *p; p++) {
97 if (type == 'U' || type == 'u')
99 /* exclude debugging symbols */
100 if (type == 'N' || type == 'n')
103 if (toupper(type) == 'A') {
104 /* Keep these useful absolute symbols */
105 if (strcmp(name, "__kernel_syscall_via_break") &&
106 strcmp(name, "__kernel_syscall_via_epc") &&
107 strcmp(name, "__kernel_sigtramp") &&
108 strcmp(name, "__gp"))
115 struct test__vmlinux_matches_kallsyms_cb_args {
116 struct machine kallsyms;
117 struct map *vmlinux_map;
121 static int test__vmlinux_matches_kallsyms_cb1(struct map *map, void *data)
123 struct test__vmlinux_matches_kallsyms_cb_args *args = data;
124 struct dso *dso = map__dso(map);
126 * If it is the kernel, kallsyms is always "[kernel.kallsyms]", while
127 * the kernel will have the path for the vmlinux file being used, so use
128 * the short name, less descriptive but the same ("[kernel]" in both
131 struct map *pair = maps__find_by_name(args->kallsyms.kmaps,
132 (dso->kernel ? dso->short_name : dso->name));
135 map__set_priv(pair, 1);
137 if (!args->header_printed) {
138 pr_info("WARN: Maps only in vmlinux:\n");
139 args->header_printed = true;
141 map__fprintf(map, stderr);
146 static int test__vmlinux_matches_kallsyms_cb2(struct map *map, void *data)
148 struct test__vmlinux_matches_kallsyms_cb_args *args = data;
150 u64 mem_start = map__unmap_ip(args->vmlinux_map, map__start(map));
151 u64 mem_end = map__unmap_ip(args->vmlinux_map, map__end(map));
153 pair = maps__find(args->kallsyms.kmaps, mem_start);
154 if (pair == NULL || map__priv(pair))
157 if (map__start(pair) == mem_start) {
158 struct dso *dso = map__dso(map);
160 if (!args->header_printed) {
161 pr_info("WARN: Maps in vmlinux with a different name in kallsyms:\n");
162 args->header_printed = true;
165 pr_info("WARN: %" PRIx64 "-%" PRIx64 " %" PRIx64 " %s in kallsyms as",
166 map__start(map), map__end(map), map__pgoff(map), dso->name);
167 if (mem_end != map__end(pair))
168 pr_info(":\nWARN: *%" PRIx64 "-%" PRIx64 " %" PRIx64,
169 map__start(pair), map__end(pair), map__pgoff(pair));
170 pr_info(" %s\n", dso->name);
171 map__set_priv(pair, 1);
176 static int test__vmlinux_matches_kallsyms_cb3(struct map *map, void *data)
178 struct test__vmlinux_matches_kallsyms_cb_args *args = data;
180 if (!map__priv(map)) {
181 if (!args->header_printed) {
182 pr_info("WARN: Maps only in kallsyms:\n");
183 args->header_printed = true;
185 map__fprintf(map, stderr);
190 static int test__vmlinux_matches_kallsyms(struct test_suite *test __maybe_unused,
191 int subtest __maybe_unused)
196 struct map *kallsyms_map;
197 struct machine vmlinux;
199 u64 mem_start, mem_end;
200 struct test__vmlinux_matches_kallsyms_cb_args args;
205 * Init the machines that will hold kernel, modules obtained from
206 * both vmlinux + .ko files and from /proc/kallsyms split by modules.
208 machine__init(&args.kallsyms, "", HOST_KERNEL_ID);
209 machine__init(&vmlinux, "", HOST_KERNEL_ID);
211 maps = machine__kernel_maps(&vmlinux);
216 * Create the kernel maps for kallsyms and the DSO where we will then
217 * load /proc/kallsyms. Also create the modules maps from /proc/modules
218 * and find the .ko files that match them in /lib/modules/`uname -r`/.
220 if (machine__create_kernel_maps(&args.kallsyms) < 0) {
221 pr_debug("machine__create_kernel_maps failed");
229 * Load and split /proc/kallsyms into multiple maps, one per module.
230 * Do not use kcore, as this test was designed before kcore support
231 * and has parts that only make sense if using the non-kcore code.
232 * XXX: extend it to stress the kcorre code as well, hint: the list
233 * of modules extracted from /proc/kcore, in its current form, can't
234 * be compacted against the list of modules found in the "vmlinux"
235 * code and with the one got from /proc/modules from the "kallsyms" code.
237 if (machine__load_kallsyms(&args.kallsyms, "/proc/kallsyms") <= 0) {
238 pr_debug("machine__load_kallsyms failed");
246 * kallsyms will be internally on demand sorted by name so that we can
247 * find the reference relocation * symbol, i.e. the symbol we will use
248 * to see if the running kernel was relocated by checking if it has the
249 * same value in the vmlinux file we load.
251 kallsyms_map = machine__kernel_map(&args.kallsyms);
256 * Now repeat step 2, this time for the vmlinux file we'll auto-locate.
258 if (machine__create_kernel_maps(&vmlinux) < 0) {
259 pr_info("machine__create_kernel_maps failed");
263 args.vmlinux_map = machine__kernel_map(&vmlinux);
268 * Locate a vmlinux file in the vmlinux path that has a buildid that
269 * matches the one of the running kernel.
271 * While doing that look if we find the ref reloc symbol, if we find it
272 * we'll have its ref_reloc_symbol.unrelocated_addr and then
273 * maps__reloc_vmlinux will notice and set proper ->[un]map_ip routines
274 * to fixup the symbols.
276 if (machine__load_vmlinux_path(&vmlinux) <= 0) {
277 pr_info("Couldn't find a vmlinux that matches the kernel running on this machine, skipping test\n");
286 * Now look at the symbols in the vmlinux DSO and check if we find all of them
287 * in the kallsyms dso. For the ones that are in both, check its names and
290 map__for_each_symbol(args.vmlinux_map, sym, nd) {
291 struct symbol *pair, *first_pair;
293 sym = rb_entry(nd, struct symbol, rb_node);
295 if (sym->start == sym->end)
298 mem_start = map__unmap_ip(args.vmlinux_map, sym->start);
299 mem_end = map__unmap_ip(args.vmlinux_map, sym->end);
301 first_pair = machine__find_kernel_symbol(&args.kallsyms, mem_start, NULL);
304 if (pair && UM(pair->start) == mem_start) {
306 if (arch__compare_symbol_names(sym->name, pair->name) == 0) {
308 * kallsyms don't have the symbol end, so we
309 * set that by using the next symbol start - 1,
310 * in some cases we get this up to a page
311 * wrong, trace_kmalloc when I was developing
312 * this code was one such example, 2106 bytes
313 * off the real size. More than that and we
314 * _really_ have a problem.
316 s64 skew = mem_end - UM(pair->end);
317 if (llabs(skew) >= page_size)
318 pr_debug("WARN: %#" PRIx64 ": diff end addr for %s v: %#" PRIx64 " k: %#" PRIx64 "\n",
319 mem_start, sym->name, mem_end,
323 * Do not count this as a failure, because we
324 * could really find a case where it's not
325 * possible to get proper function end from
330 pair = machine__find_kernel_symbol_by_name(&args.kallsyms,
333 if (UM(pair->start) == mem_start)
336 pr_debug("WARN: %#" PRIx64 ": diff name v: %s k: %s\n",
337 mem_start, sym->name, pair->name);
339 pr_debug("WARN: %#" PRIx64 ": diff name v: %s k: %s\n",
340 mem_start, sym->name, first_pair->name);
345 } else if (mem_start == map__end(args.kallsyms.vmlinux_map)) {
347 * Ignore aliases to _etext, i.e. to the end of the kernel text area,
348 * such as __indirect_thunk_end.
351 } else if (is_ignored_symbol(sym->name, sym->type)) {
353 * Ignore hidden symbols, see scripts/kallsyms.c for the details
357 pr_debug("ERR : %#" PRIx64 ": %s not on kallsyms\n",
358 mem_start, sym->name);
367 args.header_printed = false;
368 maps__for_each_map(maps, test__vmlinux_matches_kallsyms_cb1, &args);
370 args.header_printed = false;
371 maps__for_each_map(maps, test__vmlinux_matches_kallsyms_cb2, &args);
373 args.header_printed = false;
374 maps = machine__kernel_maps(&args.kallsyms);
375 maps__for_each_map(maps, test__vmlinux_matches_kallsyms_cb3, &args);
378 machine__exit(&args.kallsyms);
379 machine__exit(&vmlinux);
383 DEFINE_SUITE("vmlinux symtab matches kallsyms", vmlinux_matches_kallsyms);