|  | // 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_addresses", | 
|  | "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->short_name : dso->name)); | 
|  |  | 
|  | if (pair) | 
|  | map__set_priv(pair, 1); | 
|  | 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)) | 
|  | return 0; | 
|  |  | 
|  | if (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); | 
|  | 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); | 
|  | map__set_priv(pair, 1); | 
|  | } | 
|  | 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); |