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