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1// SPDX-License-Identifier: GPL-2.02#include <linux/compiler.h>3#include <linux/rbtree.h>4#include <inttypes.h>5#include <string.h>6#include <ctype.h>7#include <stdlib.h>8#include "dso.h"9#include "map.h"10#include "symbol.h"11#include <internal/lib.h> // page_size12#include "tests.h"13#include "debug.h"14#include "machine.h"15 16#define UM(x) map__unmap_ip(kallsyms_map, (x))17 18static bool is_ignored_symbol(const char *name, char type)19{20 /* Symbol names that exactly match to the following are ignored.*/21 static const char * const ignored_symbols[] = {22 /*23 * Symbols which vary between passes. Passes 1 and 2 must have24 * identical symbol lists. The kallsyms_* symbols below are25 * only added after pass 1, they would be included in pass 226 * when --all-symbols is specified so exclude them to get a27 * stable symbol list.28 */29 "kallsyms_offsets",30 "kallsyms_relative_base",31 "kallsyms_num_syms",32 "kallsyms_names",33 "kallsyms_markers",34 "kallsyms_token_table",35 "kallsyms_token_index",36 /* Exclude linker generated symbols which vary between passes */37 "_SDA_BASE_", /* ppc */38 "_SDA2_BASE_", /* ppc */39 NULL40 };41 42 /* Symbol names that begin with the following are ignored.*/43 static const char * const ignored_prefixes[] = {44 "$", /* local symbols for ARM, MIPS, etc. */45 ".L", /* local labels, .LBB,.Ltmpxxx,.L__unnamed_xx,.LASANPC, etc. */46 "__crc_", /* modversions */47 "__efistub_", /* arm64 EFI stub namespace */48 "__kvm_nvhe_$", /* arm64 local symbols in non-VHE KVM namespace */49 "__kvm_nvhe_.L", /* arm64 local symbols in non-VHE KVM namespace */50 "__AArch64ADRPThunk_", /* arm64 lld */51 "__ARMV5PILongThunk_", /* arm lld */52 "__ARMV7PILongThunk_",53 "__ThumbV7PILongThunk_",54 "__LA25Thunk_", /* mips lld */55 "__microLA25Thunk_",56 NULL57 };58 59 /* Symbol names that end with the following are ignored.*/60 static const char * const ignored_suffixes[] = {61 "_from_arm", /* arm */62 "_from_thumb", /* arm */63 "_veneer", /* arm */64 NULL65 };66 67 /* Symbol names that contain the following are ignored.*/68 static const char * const ignored_matches[] = {69 ".long_branch.", /* ppc stub */70 ".plt_branch.", /* ppc stub */71 NULL72 };73 74 const char * const *p;75 76 for (p = ignored_symbols; *p; p++)77 if (!strcmp(name, *p))78 return true;79 80 for (p = ignored_prefixes; *p; p++)81 if (!strncmp(name, *p, strlen(*p)))82 return true;83 84 for (p = ignored_suffixes; *p; p++) {85 int l = strlen(name) - strlen(*p);86 87 if (l >= 0 && !strcmp(name + l, *p))88 return true;89 }90 91 for (p = ignored_matches; *p; p++) {92 if (strstr(name, *p))93 return true;94 }95 96 if (type == 'U' || type == 'u')97 return true;98 /* exclude debugging symbols */99 if (type == 'N' || type == 'n')100 return true;101 102 if (toupper(type) == 'A') {103 /* Keep these useful absolute symbols */104 if (strcmp(name, "__kernel_syscall_via_break") &&105 strcmp(name, "__kernel_syscall_via_epc") &&106 strcmp(name, "__kernel_sigtramp") &&107 strcmp(name, "__gp"))108 return true;109 }110 111 return false;112}113 114struct test__vmlinux_matches_kallsyms_cb_args {115 struct machine kallsyms;116 struct map *vmlinux_map;117 bool header_printed;118};119 120static int test__vmlinux_matches_kallsyms_cb1(struct map *map, void *data)121{122 struct test__vmlinux_matches_kallsyms_cb_args *args = data;123 struct dso *dso = map__dso(map);124 /*125 * If it is the kernel, kallsyms is always "[kernel.kallsyms]", while126 * the kernel will have the path for the vmlinux file being used, so use127 * the short name, less descriptive but the same ("[kernel]" in both128 * cases.129 */130 struct map *pair = maps__find_by_name(args->kallsyms.kmaps,131 (dso__kernel(dso) ? dso__short_name(dso) : dso__name(dso)));132 133 if (pair) {134 map__set_priv(pair);135 map__put(pair);136 } else {137 if (!args->header_printed) {138 pr_info("WARN: Maps only in vmlinux:\n");139 args->header_printed = true;140 }141 map__fprintf(map, stderr);142 }143 return 0;144}145 146static int test__vmlinux_matches_kallsyms_cb2(struct map *map, void *data)147{148 struct test__vmlinux_matches_kallsyms_cb_args *args = data;149 struct map *pair;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));152 153 pair = maps__find(args->kallsyms.kmaps, mem_start);154 155 if (pair != NULL && !map__priv(pair) && map__start(pair) == mem_start) {156 struct dso *dso = map__dso(map);157 158 if (!args->header_printed) {159 pr_info("WARN: Maps in vmlinux with a different name in kallsyms:\n");160 args->header_printed = true;161 }162 163 pr_info("WARN: %" PRIx64 "-%" PRIx64 " %" PRIx64 " %s in kallsyms as",164 map__start(map), map__end(map), map__pgoff(map), dso__name(dso));165 if (mem_end != map__end(pair))166 pr_info(":\nWARN: *%" PRIx64 "-%" PRIx64 " %" PRIx64,167 map__start(pair), map__end(pair), map__pgoff(pair));168 pr_info(" %s\n", dso__name(dso));169 map__set_priv(pair);170 }171 map__put(pair);172 return 0;173}174 175static int test__vmlinux_matches_kallsyms_cb3(struct map *map, void *data)176{177 struct test__vmlinux_matches_kallsyms_cb_args *args = data;178 179 if (!map__priv(map)) {180 if (!args->header_printed) {181 pr_info("WARN: Maps only in kallsyms:\n");182 args->header_printed = true;183 }184 map__fprintf(map, stderr);185 }186 return 0;187}188 189static int test__vmlinux_matches_kallsyms(struct test_suite *test __maybe_unused,190 int subtest __maybe_unused)191{192 int err = TEST_FAIL;193 struct rb_node *nd;194 struct symbol *sym;195 struct map *kallsyms_map;196 struct machine vmlinux;197 struct maps *maps;198 u64 mem_start, mem_end;199 struct test__vmlinux_matches_kallsyms_cb_args args;200 201 /*202 * Step 1:203 *204 * Init the machines that will hold kernel, modules obtained from205 * both vmlinux + .ko files and from /proc/kallsyms split by modules.206 */207 machine__init(&args.kallsyms, "", HOST_KERNEL_ID);208 machine__init(&vmlinux, "", HOST_KERNEL_ID);209 210 maps = machine__kernel_maps(&vmlinux);211 212 /*213 * Step 2:214 *215 * Create the kernel maps for kallsyms and the DSO where we will then216 * load /proc/kallsyms. Also create the modules maps from /proc/modules217 * and find the .ko files that match them in /lib/modules/`uname -r`/.218 */219 if (machine__create_kernel_maps(&args.kallsyms) < 0) {220 pr_debug("machine__create_kernel_maps failed");221 err = TEST_SKIP;222 goto out;223 }224 225 /*226 * Step 3:227 *228 * Load and split /proc/kallsyms into multiple maps, one per module.229 * Do not use kcore, as this test was designed before kcore support230 * and has parts that only make sense if using the non-kcore code.231 * XXX: extend it to stress the kcorre code as well, hint: the list232 * of modules extracted from /proc/kcore, in its current form, can't233 * be compacted against the list of modules found in the "vmlinux"234 * code and with the one got from /proc/modules from the "kallsyms" code.235 */236 if (machine__load_kallsyms(&args.kallsyms, "/proc/kallsyms") <= 0) {237 pr_debug("machine__load_kallsyms failed");238 err = TEST_SKIP;239 goto out;240 }241 242 /*243 * Step 4:244 *245 * kallsyms will be internally on demand sorted by name so that we can246 * find the reference relocation * symbol, i.e. the symbol we will use247 * to see if the running kernel was relocated by checking if it has the248 * same value in the vmlinux file we load.249 */250 kallsyms_map = machine__kernel_map(&args.kallsyms);251 252 /*253 * Step 5:254 *255 * Now repeat step 2, this time for the vmlinux file we'll auto-locate.256 */257 if (machine__create_kernel_maps(&vmlinux) < 0) {258 pr_info("machine__create_kernel_maps failed");259 goto out;260 }261 262 args.vmlinux_map = machine__kernel_map(&vmlinux);263 264 /*265 * Step 6:266 *267 * Locate a vmlinux file in the vmlinux path that has a buildid that268 * matches the one of the running kernel.269 *270 * While doing that look if we find the ref reloc symbol, if we find it271 * we'll have its ref_reloc_symbol.unrelocated_addr and then272 * maps__reloc_vmlinux will notice and set proper ->[un]map_ip routines273 * to fixup the symbols.274 */275 if (machine__load_vmlinux_path(&vmlinux) <= 0) {276 pr_info("Couldn't find a vmlinux that matches the kernel running on this machine, skipping test\n");277 err = TEST_SKIP;278 goto out;279 }280 281 err = 0;282 /*283 * Step 7:284 *285 * Now look at the symbols in the vmlinux DSO and check if we find all of them286 * in the kallsyms dso. For the ones that are in both, check its names and287 * end addresses too.288 */289 map__for_each_symbol(args.vmlinux_map, sym, nd) {290 struct symbol *pair, *first_pair;291 292 sym = rb_entry(nd, struct symbol, rb_node);293 294 if (sym->start == sym->end)295 continue;296 297 mem_start = map__unmap_ip(args.vmlinux_map, sym->start);298 mem_end = map__unmap_ip(args.vmlinux_map, sym->end);299 300 first_pair = machine__find_kernel_symbol(&args.kallsyms, mem_start, NULL);301 pair = first_pair;302 303 if (pair && UM(pair->start) == mem_start) {304next_pair:305 if (arch__compare_symbol_names(sym->name, pair->name) == 0) {306 /*307 * kallsyms don't have the symbol end, so we308 * set that by using the next symbol start - 1,309 * in some cases we get this up to a page310 * wrong, trace_kmalloc when I was developing311 * this code was one such example, 2106 bytes312 * off the real size. More than that and we313 * _really_ have a problem.314 */315 s64 skew = mem_end - UM(pair->end);316 if (llabs(skew) >= page_size)317 pr_debug("WARN: %#" PRIx64 ": diff end addr for %s v: %#" PRIx64 " k: %#" PRIx64 "\n",318 mem_start, sym->name, mem_end,319 UM(pair->end));320 321 /*322 * Do not count this as a failure, because we323 * could really find a case where it's not324 * possible to get proper function end from325 * kallsyms.326 */327 continue;328 } else {329 pair = machine__find_kernel_symbol_by_name(&args.kallsyms,330 sym->name, NULL);331 if (pair) {332 if (UM(pair->start) == mem_start)333 goto next_pair;334 335 pr_debug("WARN: %#" PRIx64 ": diff name v: %s k: %s\n",336 mem_start, sym->name, pair->name);337 } else {338 pr_debug("WARN: %#" PRIx64 ": diff name v: %s k: %s\n",339 mem_start, sym->name, first_pair->name);340 }341 342 continue;343 }344 } else if (mem_start == map__end(args.kallsyms.vmlinux_map)) {345 /*346 * Ignore aliases to _etext, i.e. to the end of the kernel text area,347 * such as __indirect_thunk_end.348 */349 continue;350 } else if (is_ignored_symbol(sym->name, sym->type)) {351 /*352 * Ignore hidden symbols, see scripts/kallsyms.c for the details353 */354 continue;355 } else {356 pr_debug("ERR : %#" PRIx64 ": %s not on kallsyms\n",357 mem_start, sym->name);358 }359 360 err = -1;361 }362 363 if (verbose <= 0)364 goto out;365 366 args.header_printed = false;367 maps__for_each_map(maps, test__vmlinux_matches_kallsyms_cb1, &args);368 369 args.header_printed = false;370 maps__for_each_map(maps, test__vmlinux_matches_kallsyms_cb2, &args);371 372 args.header_printed = false;373 maps = machine__kernel_maps(&args.kallsyms);374 maps__for_each_map(maps, test__vmlinux_matches_kallsyms_cb3, &args);375 376out:377 machine__exit(&args.kallsyms);378 machine__exit(&vmlinux);379 return err;380}381 382DEFINE_SUITE("vmlinux symtab matches kallsyms", vmlinux_matches_kallsyms);383