| // SPDX-License-Identifier: GPL-2.0 |
| #include <linux/compiler.h> |
| #include <linux/rbtree.h> |
| #include <inttypes.h> |
| #include <string.h> |
| #include <ctype.h> |
| #include <stdlib.h> |
| #include "dso.h" |
| #include "map.h" |
| #include "symbol.h" |
| #include <internal/lib.h> // page_size |
| #include "tests.h" |
| #include "debug.h" |
| #include "machine.h" |
| |
| #define UM(x) map__unmap_ip(kallsyms_map, (x)) |
| |
| static bool is_ignored_symbol(const char *name, char type) |
| { |
| /* Symbol names that exactly match to the following are ignored.*/ |
| static const char * const ignored_symbols[] = { |
| /* |
| * Symbols which vary between passes. Passes 1 and 2 must have |
| * identical symbol lists. The kallsyms_* symbols below are |
| * only added after pass 1, they would be included in pass 2 |
| * when --all-symbols is specified so exclude them to get a |
| * stable symbol list. |
| */ |
| "kallsyms_offsets", |
| "kallsyms_relative_base", |
| "kallsyms_num_syms", |
| "kallsyms_names", |
| "kallsyms_markers", |
| "kallsyms_token_table", |
| "kallsyms_token_index", |
| /* Exclude linker generated symbols which vary between passes */ |
| "_SDA_BASE_", /* ppc */ |
| "_SDA2_BASE_", /* ppc */ |
| NULL |
| }; |
| |
| /* Symbol names that begin with the following are ignored.*/ |
| static const char * const ignored_prefixes[] = { |
| "$", /* local symbols for ARM, MIPS, etc. */ |
| ".L", /* local labels, .LBB,.Ltmpxxx,.L__unnamed_xx,.LASANPC, etc. */ |
| "__crc_", /* modversions */ |
| "__efistub_", /* arm64 EFI stub namespace */ |
| "__kvm_nvhe_$", /* arm64 local symbols in non-VHE KVM namespace */ |
| "__kvm_nvhe_.L", /* arm64 local symbols in non-VHE KVM namespace */ |
| "__AArch64ADRPThunk_", /* arm64 lld */ |
| "__ARMV5PILongThunk_", /* arm lld */ |
| "__ARMV7PILongThunk_", |
| "__ThumbV7PILongThunk_", |
| "__LA25Thunk_", /* mips lld */ |
| "__microLA25Thunk_", |
| NULL |
| }; |
| |
| /* Symbol names that end with the following are ignored.*/ |
| static const char * const ignored_suffixes[] = { |
| "_from_arm", /* arm */ |
| "_from_thumb", /* arm */ |
| "_veneer", /* arm */ |
| NULL |
| }; |
| |
| /* Symbol names that contain the following are ignored.*/ |
| static const char * const ignored_matches[] = { |
| ".long_branch.", /* ppc stub */ |
| ".plt_branch.", /* ppc stub */ |
| NULL |
| }; |
| |
| const char * const *p; |
| |
| for (p = ignored_symbols; *p; p++) |
| if (!strcmp(name, *p)) |
| return true; |
| |
| for (p = ignored_prefixes; *p; p++) |
| if (!strncmp(name, *p, strlen(*p))) |
| return true; |
| |
| for (p = ignored_suffixes; *p; p++) { |
| int l = strlen(name) - strlen(*p); |
| |
| if (l >= 0 && !strcmp(name + l, *p)) |
| return true; |
| } |
| |
| for (p = ignored_matches; *p; p++) { |
| if (strstr(name, *p)) |
| return true; |
| } |
| |
| if (type == 'U' || type == 'u') |
| return true; |
| /* exclude debugging symbols */ |
| if (type == 'N' || type == 'n') |
| return true; |
| |
| if (toupper(type) == 'A') { |
| /* Keep these useful absolute symbols */ |
| if (strcmp(name, "__kernel_syscall_via_break") && |
| strcmp(name, "__kernel_syscall_via_epc") && |
| strcmp(name, "__kernel_sigtramp") && |
| strcmp(name, "__gp")) |
| return true; |
| } |
| |
| return false; |
| } |
| |
| struct test__vmlinux_matches_kallsyms_cb_args { |
| struct machine kallsyms; |
| struct map *vmlinux_map; |
| bool header_printed; |
| }; |
| |
| static int test__vmlinux_matches_kallsyms_cb1(struct map *map, void *data) |
| { |
| struct test__vmlinux_matches_kallsyms_cb_args *args = data; |
| struct dso *dso = map__dso(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. |
| */ |
| struct map *pair = maps__find_by_name(args->kallsyms.kmaps, |
| (dso__kernel(dso) ? dso__short_name(dso) : dso__name(dso))); |
| |
| if (pair) { |
| map__set_priv(pair); |
| map__put(pair); |
| } else { |
| if (!args->header_printed) { |
| pr_info("WARN: Maps only in vmlinux:\n"); |
| args->header_printed = true; |
| } |
| map__fprintf(map, stderr); |
| } |
| return 0; |
| } |
| |
| static int test__vmlinux_matches_kallsyms_cb2(struct map *map, void *data) |
| { |
| struct test__vmlinux_matches_kallsyms_cb_args *args = data; |
| struct map *pair; |
| u64 mem_start = map__unmap_ip(args->vmlinux_map, map__start(map)); |
| u64 mem_end = map__unmap_ip(args->vmlinux_map, map__end(map)); |
| |
| pair = maps__find(args->kallsyms.kmaps, mem_start); |
| |
| if (pair != NULL && !map__priv(pair) && map__start(pair) == mem_start) { |
| struct dso *dso = map__dso(map); |
| |
| if (!args->header_printed) { |
| pr_info("WARN: Maps in vmlinux with a different name in kallsyms:\n"); |
| args->header_printed = true; |
| } |
| |
| pr_info("WARN: %" PRIx64 "-%" PRIx64 " %" PRIx64 " %s in kallsyms as", |
| map__start(map), map__end(map), map__pgoff(map), dso__name(dso)); |
| if (mem_end != map__end(pair)) |
| pr_info(":\nWARN: *%" PRIx64 "-%" PRIx64 " %" PRIx64, |
| map__start(pair), map__end(pair), map__pgoff(pair)); |
| pr_info(" %s\n", dso__name(dso)); |
| map__set_priv(pair); |
| } |
| map__put(pair); |
| return 0; |
| } |
| |
| static int test__vmlinux_matches_kallsyms_cb3(struct map *map, void *data) |
| { |
| struct test__vmlinux_matches_kallsyms_cb_args *args = data; |
| |
| if (!map__priv(map)) { |
| if (!args->header_printed) { |
| pr_info("WARN: Maps only in kallsyms:\n"); |
| args->header_printed = true; |
| } |
| map__fprintf(map, stderr); |
| } |
| return 0; |
| } |
| |
| static int test__vmlinux_matches_kallsyms(struct test_suite *test __maybe_unused, |
| int subtest __maybe_unused) |
| { |
| int err = TEST_FAIL; |
| struct rb_node *nd; |
| struct symbol *sym; |
| struct map *kallsyms_map; |
| struct machine vmlinux; |
| struct maps *maps; |
| u64 mem_start, mem_end; |
| struct test__vmlinux_matches_kallsyms_cb_args args; |
| |
| /* |
| * 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(&args.kallsyms, "", HOST_KERNEL_ID); |
| machine__init(&vmlinux, "", HOST_KERNEL_ID); |
| |
| maps = machine__kernel_maps(&vmlinux); |
| |
| /* |
| * 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(&args.kallsyms) < 0) { |
| pr_debug("machine__create_kernel_maps failed"); |
| err = TEST_SKIP; |
| goto out; |
| } |
| |
| /* |
| * Step 3: |
| * |
| * Load and split /proc/kallsyms into multiple maps, one per module. |
| * Do not use kcore, as this test was designed before kcore support |
| * and has parts that only make sense if using the non-kcore code. |
| * XXX: extend it to stress the kcorre code as well, hint: the list |
| * of modules extracted from /proc/kcore, in its current form, can't |
| * be compacted against the list of modules found in the "vmlinux" |
| * code and with the one got from /proc/modules from the "kallsyms" code. |
| */ |
| if (machine__load_kallsyms(&args.kallsyms, "/proc/kallsyms") <= 0) { |
| pr_debug("machine__load_kallsyms failed"); |
| err = TEST_SKIP; |
| 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(&args.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_info("machine__create_kernel_maps failed"); |
| goto out; |
| } |
| |
| args.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) <= 0) { |
| pr_info("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. |
| */ |
| map__for_each_symbol(args.vmlinux_map, sym, nd) { |
| struct symbol *pair, *first_pair; |
| |
| sym = rb_entry(nd, struct symbol, rb_node); |
| |
| if (sym->start == sym->end) |
| continue; |
| |
| mem_start = map__unmap_ip(args.vmlinux_map, sym->start); |
| mem_end = map__unmap_ip(args.vmlinux_map, sym->end); |
| |
| first_pair = machine__find_kernel_symbol(&args.kallsyms, mem_start, NULL); |
| pair = first_pair; |
| |
| if (pair && UM(pair->start) == mem_start) { |
| next_pair: |
| if (arch__compare_symbol_names(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("WARN: %#" 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(&args.kallsyms, |
| sym->name, NULL); |
| if (pair) { |
| if (UM(pair->start) == mem_start) |
| goto next_pair; |
| |
| pr_debug("WARN: %#" PRIx64 ": diff name v: %s k: %s\n", |
| mem_start, sym->name, pair->name); |
| } else { |
| pr_debug("WARN: %#" PRIx64 ": diff name v: %s k: %s\n", |
| mem_start, sym->name, first_pair->name); |
| } |
| |
| continue; |
| } |
| } else if (mem_start == map__end(args.kallsyms.vmlinux_map)) { |
| /* |
| * Ignore aliases to _etext, i.e. to the end of the kernel text area, |
| * such as __indirect_thunk_end. |
| */ |
| continue; |
| } else if (is_ignored_symbol(sym->name, sym->type)) { |
| /* |
| * Ignore hidden symbols, see scripts/kallsyms.c for the details |
| */ |
| continue; |
| } else { |
| pr_debug("ERR : %#" PRIx64 ": %s not on kallsyms\n", |
| mem_start, sym->name); |
| } |
| |
| err = -1; |
| } |
| |
| if (verbose <= 0) |
| goto out; |
| |
| args.header_printed = false; |
| maps__for_each_map(maps, test__vmlinux_matches_kallsyms_cb1, &args); |
| |
| args.header_printed = false; |
| maps__for_each_map(maps, test__vmlinux_matches_kallsyms_cb2, &args); |
| |
| args.header_printed = false; |
| maps = machine__kernel_maps(&args.kallsyms); |
| maps__for_each_map(maps, test__vmlinux_matches_kallsyms_cb3, &args); |
| |
| out: |
| machine__exit(&args.kallsyms); |
| machine__exit(&vmlinux); |
| return err; |
| } |
| |
| DEFINE_SUITE("vmlinux symtab matches kallsyms", vmlinux_matches_kallsyms); |