1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/compiler.h>
3 #include <linux/rbtree.h>
13 #define UM(x) kallsyms_map->unmap_ip(kallsyms_map, (x))
15 int test__vmlinux_matches_kallsyms(struct test *test __maybe_unused, int subtest __maybe_unused)
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;
30 * Init the machines that will hold kernel, modules obtained from
31 * both vmlinux + .ko files and from /proc/kallsyms split by modules.
33 machine__init(&kallsyms, "", HOST_KERNEL_ID);
34 machine__init(&vmlinux, "", HOST_KERNEL_ID);
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`/.
43 if (machine__create_kernel_maps(&kallsyms) < 0) {
44 pr_debug("machine__create_kernel_maps ");
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.
59 if (__machine__load_kallsyms(&kallsyms, "/proc/kallsyms", type, true) <= 0) {
60 pr_debug("dso__load_kallsyms ");
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.
72 kallsyms_map = machine__kernel_map(&kallsyms);
77 * Now repeat step 2, this time for the vmlinux file we'll auto-locate.
79 if (machine__create_kernel_maps(&vmlinux) < 0) {
80 pr_debug("machine__create_kernel_maps ");
84 vmlinux_map = machine__kernel_map(&vmlinux);
89 * Locate a vmlinux file in the vmlinux path that has a buildid that
90 * matches the one of the running kernel.
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.
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");
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
111 for (nd = rb_first(&vmlinux_map->dso->symbols[type]); nd; nd = rb_next(nd)) {
112 struct symbol *pair, *first_pair;
114 sym = rb_entry(nd, struct symbol, rb_node);
116 if (sym->start == sym->end)
119 mem_start = vmlinux_map->unmap_ip(vmlinux_map, sym->start);
120 mem_end = vmlinux_map->unmap_ip(vmlinux_map, sym->end);
122 first_pair = machine__find_kernel_symbol(&kallsyms, type,
126 if (pair && UM(pair->start) == mem_start) {
128 if (arch__compare_symbol_names(sym->name, pair->name) == 0) {
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.
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,
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
152 pair = machine__find_kernel_symbol_by_name(&kallsyms, type, sym->name, NULL);
154 if (UM(pair->start) == mem_start)
157 pr_debug("WARN: %#" PRIx64 ": diff name v: %s k: %s\n",
158 mem_start, sym->name, pair->name);
160 pr_debug("WARN: %#" PRIx64 ": diff name v: %s k: %s\n",
161 mem_start, sym->name, first_pair->name);
167 pr_debug("ERR : %#" PRIx64 ": %s not on kallsyms\n",
168 mem_start, sym->name);
176 header_printed = false;
178 for (map = maps__first(maps); map; map = map__next(map)) {
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
186 pair = map_groups__find_by_name(&kallsyms.kmaps, type,
188 map->dso->short_name :
193 if (!header_printed) {
194 pr_info("WARN: Maps only in vmlinux:\n");
195 header_printed = true;
197 map__fprintf(map, stderr);
201 header_printed = false;
203 for (map = maps__first(maps); map; map = map__next(map)) {
206 mem_start = vmlinux_map->unmap_ip(vmlinux_map, map->start);
207 mem_end = vmlinux_map->unmap_ip(vmlinux_map, map->end);
209 pair = map_groups__find(&kallsyms.kmaps, type, mem_start);
210 if (pair == NULL || pair->priv)
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;
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);
229 header_printed = false;
231 maps = &kallsyms.kmaps.maps[type];
233 for (map = maps__first(maps); map; map = map__next(map)) {
235 if (!header_printed) {
236 pr_info("WARN: Maps only in kallsyms:\n");
237 header_printed = true;
239 map__fprintf(map, stderr);
243 machine__exit(&kallsyms);
244 machine__exit(&vmlinux);