1 #include <linux/compiler.h>
2 #include <linux/rbtree.h>
11 static int vmlinux_matches_kallsyms_filter(struct map *map __maybe_unused,
14 bool *visited = symbol__priv(sym);
19 #define UM(x) kallsyms_map->unmap_ip(kallsyms_map, (x))
21 int test__vmlinux_matches_kallsyms(void)
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;
34 * Init the machines that will hold kernel, modules obtained from
35 * both vmlinux + .ko files and from /proc/kallsyms split by modules.
37 machine__init(&kallsyms, "", HOST_KERNEL_ID);
38 machine__init(&vmlinux, "", HOST_KERNEL_ID);
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`/.
47 if (machine__create_kernel_maps(&kallsyms) < 0) {
48 pr_debug("machine__create_kernel_maps ");
55 * Load and split /proc/kallsyms into multiple maps, one per module.
57 if (machine__load_kallsyms(&kallsyms, "/proc/kallsyms", type, NULL) <= 0) {
58 pr_debug("dso__load_kallsyms ");
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.
70 kallsyms_map = machine__kernel_map(&kallsyms, type);
75 * Now repeat step 2, this time for the vmlinux file we'll auto-locate.
77 if (machine__create_kernel_maps(&vmlinux) < 0) {
78 pr_debug("machine__create_kernel_maps ");
82 vmlinux_map = machine__kernel_map(&vmlinux, type);
87 * Locate a vmlinux file in the vmlinux path that has a buildid that
88 * matches the one of the running kernel.
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.
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");
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
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;
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,
123 mem_start, NULL, NULL);
126 if (pair && UM(pair->start) == mem_start) {
128 if (strcmp(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("%#" 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
155 nnd = backwards ? rb_prev(&pair->rb_node) :
156 rb_next(&pair->rb_node);
158 struct symbol *next = rb_entry(nnd, struct symbol, rb_node);
160 if (UM(next->start) == mem_start) {
172 pr_debug("%#" PRIx64 ": diff name v: %s k: %s\n",
173 mem_start, sym->name, pair->name);
176 pr_debug("%#" PRIx64 ": %s not on kallsyms\n",
177 mem_start, sym->name);
185 pr_info("Maps only in vmlinux:\n");
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;
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
195 pair = map_groups__find_by_name(&kallsyms.kmaps, type,
197 pos->dso->short_name :
202 map__fprintf(pos, stderr);
205 pr_info("Maps in vmlinux with a different name in kallsyms:\n");
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;
210 mem_start = vmlinux_map->unmap_ip(vmlinux_map, pos->start);
211 mem_end = vmlinux_map->unmap_ip(vmlinux_map, pos->end);
213 pair = map_groups__find(&kallsyms.kmaps, type, mem_start);
214 if (pair == NULL || pair->priv)
217 if (pair->start == mem_start) {
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);
229 pr_info("Maps only in kallsyms:\n");
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);
236 map__fprintf(pos, stderr);
239 machine__exit(&kallsyms);
240 machine__exit(&vmlinux);