| /* Postprocess module symbol versions |
| * |
| * Copyright 2003 Kai Germaschewski |
| * Copyright 2002-2004 Rusty Russell, IBM Corporation |
| * Copyright 2006-2008 Sam Ravnborg |
| * Based in part on module-init-tools/depmod.c,file2alias |
| * |
| * This software may be used and distributed according to the terms |
| * of the GNU General Public License, incorporated herein by reference. |
| * |
| * Usage: modpost vmlinux module1.o module2.o ... |
| */ |
| |
| #define _GNU_SOURCE |
| #include <elf.h> |
| #include <fnmatch.h> |
| #include <stdio.h> |
| #include <ctype.h> |
| #include <string.h> |
| #include <limits.h> |
| #include <stdbool.h> |
| #include <errno.h> |
| #include "modpost.h" |
| #include "../../include/linux/license.h" |
| |
| /* Are we using CONFIG_MODVERSIONS? */ |
| static bool modversions; |
| /* Is CONFIG_MODULE_SRCVERSION_ALL set? */ |
| static bool all_versions; |
| /* If we are modposting external module set to 1 */ |
| static bool external_module; |
| /* Only warn about unresolved symbols */ |
| static bool warn_unresolved; |
| |
| static int sec_mismatch_count; |
| static bool sec_mismatch_warn_only = true; |
| /* ignore missing files */ |
| static bool ignore_missing_files; |
| /* If set to 1, only warn (instead of error) about missing ns imports */ |
| static bool allow_missing_ns_imports; |
| |
| static bool error_occurred; |
| |
| /* |
| * Cut off the warnings when there are too many. This typically occurs when |
| * vmlinux is missing. ('make modules' without building vmlinux.) |
| */ |
| #define MAX_UNRESOLVED_REPORTS 10 |
| static unsigned int nr_unresolved; |
| |
| /* In kernel, this size is defined in linux/module.h; |
| * here we use Elf_Addr instead of long for covering cross-compile |
| */ |
| |
| #define MODULE_NAME_LEN (64 - sizeof(Elf_Addr)) |
| |
| void __attribute__((format(printf, 2, 3))) |
| modpost_log(enum loglevel loglevel, const char *fmt, ...) |
| { |
| va_list arglist; |
| |
| switch (loglevel) { |
| case LOG_WARN: |
| fprintf(stderr, "WARNING: "); |
| break; |
| case LOG_ERROR: |
| fprintf(stderr, "ERROR: "); |
| break; |
| case LOG_FATAL: |
| fprintf(stderr, "FATAL: "); |
| break; |
| default: /* invalid loglevel, ignore */ |
| break; |
| } |
| |
| fprintf(stderr, "modpost: "); |
| |
| va_start(arglist, fmt); |
| vfprintf(stderr, fmt, arglist); |
| va_end(arglist); |
| |
| if (loglevel == LOG_FATAL) |
| exit(1); |
| if (loglevel == LOG_ERROR) |
| error_occurred = true; |
| } |
| |
| static inline bool strends(const char *str, const char *postfix) |
| { |
| if (strlen(str) < strlen(postfix)) |
| return false; |
| |
| return strcmp(str + strlen(str) - strlen(postfix), postfix) == 0; |
| } |
| |
| void *do_nofail(void *ptr, const char *expr) |
| { |
| if (!ptr) |
| fatal("Memory allocation failure: %s.\n", expr); |
| |
| return ptr; |
| } |
| |
| char *read_text_file(const char *filename) |
| { |
| struct stat st; |
| size_t nbytes; |
| int fd; |
| char *buf; |
| |
| fd = open(filename, O_RDONLY); |
| if (fd < 0) { |
| perror(filename); |
| exit(1); |
| } |
| |
| if (fstat(fd, &st) < 0) { |
| perror(filename); |
| exit(1); |
| } |
| |
| buf = NOFAIL(malloc(st.st_size + 1)); |
| |
| nbytes = st.st_size; |
| |
| while (nbytes) { |
| ssize_t bytes_read; |
| |
| bytes_read = read(fd, buf, nbytes); |
| if (bytes_read < 0) { |
| perror(filename); |
| exit(1); |
| } |
| |
| nbytes -= bytes_read; |
| } |
| buf[st.st_size] = '\0'; |
| |
| close(fd); |
| |
| return buf; |
| } |
| |
| char *get_line(char **stringp) |
| { |
| char *orig = *stringp, *next; |
| |
| /* do not return the unwanted extra line at EOF */ |
| if (!orig || *orig == '\0') |
| return NULL; |
| |
| /* don't use strsep here, it is not available everywhere */ |
| next = strchr(orig, '\n'); |
| if (next) |
| *next++ = '\0'; |
| |
| *stringp = next; |
| |
| return orig; |
| } |
| |
| /* A list of all modules we processed */ |
| LIST_HEAD(modules); |
| |
| static struct module *find_module(const char *modname) |
| { |
| struct module *mod; |
| |
| list_for_each_entry(mod, &modules, list) { |
| if (strcmp(mod->name, modname) == 0) |
| return mod; |
| } |
| return NULL; |
| } |
| |
| static struct module *new_module(const char *name, size_t namelen) |
| { |
| struct module *mod; |
| |
| mod = NOFAIL(malloc(sizeof(*mod) + namelen + 1)); |
| memset(mod, 0, sizeof(*mod)); |
| |
| INIT_LIST_HEAD(&mod->exported_symbols); |
| INIT_LIST_HEAD(&mod->unresolved_symbols); |
| INIT_LIST_HEAD(&mod->missing_namespaces); |
| INIT_LIST_HEAD(&mod->imported_namespaces); |
| |
| memcpy(mod->name, name, namelen); |
| mod->name[namelen] = '\0'; |
| mod->is_vmlinux = (strcmp(mod->name, "vmlinux") == 0); |
| |
| /* |
| * Set mod->is_gpl_compatible to true by default. If MODULE_LICENSE() |
| * is missing, do not check the use for EXPORT_SYMBOL_GPL() becasue |
| * modpost will exit wiht error anyway. |
| */ |
| mod->is_gpl_compatible = true; |
| |
| list_add_tail(&mod->list, &modules); |
| |
| return mod; |
| } |
| |
| /* A hash of all exported symbols, |
| * struct symbol is also used for lists of unresolved symbols */ |
| |
| #define SYMBOL_HASH_SIZE 1024 |
| |
| struct symbol { |
| struct symbol *next; |
| struct list_head list; /* link to module::exported_symbols or module::unresolved_symbols */ |
| struct module *module; |
| char *namespace; |
| unsigned int crc; |
| bool crc_valid; |
| bool weak; |
| bool is_gpl_only; /* exported by EXPORT_SYMBOL_GPL */ |
| char name[]; |
| }; |
| |
| static struct symbol *symbolhash[SYMBOL_HASH_SIZE]; |
| |
| /* This is based on the hash algorithm from gdbm, via tdb */ |
| static inline unsigned int tdb_hash(const char *name) |
| { |
| unsigned value; /* Used to compute the hash value. */ |
| unsigned i; /* Used to cycle through random values. */ |
| |
| /* Set the initial value from the key size. */ |
| for (value = 0x238F13AF * strlen(name), i = 0; name[i]; i++) |
| value = (value + (((unsigned char *)name)[i] << (i*5 % 24))); |
| |
| return (1103515243 * value + 12345); |
| } |
| |
| /** |
| * Allocate a new symbols for use in the hash of exported symbols or |
| * the list of unresolved symbols per module |
| **/ |
| static struct symbol *alloc_symbol(const char *name) |
| { |
| struct symbol *s = NOFAIL(malloc(sizeof(*s) + strlen(name) + 1)); |
| |
| memset(s, 0, sizeof(*s)); |
| strcpy(s->name, name); |
| |
| return s; |
| } |
| |
| /* For the hash of exported symbols */ |
| static void hash_add_symbol(struct symbol *sym) |
| { |
| unsigned int hash; |
| |
| hash = tdb_hash(sym->name) % SYMBOL_HASH_SIZE; |
| sym->next = symbolhash[hash]; |
| symbolhash[hash] = sym; |
| } |
| |
| static void sym_add_unresolved(const char *name, struct module *mod, bool weak) |
| { |
| struct symbol *sym; |
| |
| sym = alloc_symbol(name); |
| sym->weak = weak; |
| |
| list_add_tail(&sym->list, &mod->unresolved_symbols); |
| } |
| |
| static struct symbol *sym_find_with_module(const char *name, struct module *mod) |
| { |
| struct symbol *s; |
| |
| /* For our purposes, .foo matches foo. PPC64 needs this. */ |
| if (name[0] == '.') |
| name++; |
| |
| for (s = symbolhash[tdb_hash(name) % SYMBOL_HASH_SIZE]; s; s = s->next) { |
| if (strcmp(s->name, name) == 0 && (!mod || s->module == mod)) |
| return s; |
| } |
| return NULL; |
| } |
| |
| static struct symbol *find_symbol(const char *name) |
| { |
| return sym_find_with_module(name, NULL); |
| } |
| |
| struct namespace_list { |
| struct list_head list; |
| char namespace[]; |
| }; |
| |
| static bool contains_namespace(struct list_head *head, const char *namespace) |
| { |
| struct namespace_list *list; |
| |
| list_for_each_entry(list, head, list) { |
| if (!strcmp(list->namespace, namespace)) |
| return true; |
| } |
| |
| return false; |
| } |
| |
| static void add_namespace(struct list_head *head, const char *namespace) |
| { |
| struct namespace_list *ns_entry; |
| |
| if (!contains_namespace(head, namespace)) { |
| ns_entry = NOFAIL(malloc(sizeof(*ns_entry) + |
| strlen(namespace) + 1)); |
| strcpy(ns_entry->namespace, namespace); |
| list_add_tail(&ns_entry->list, head); |
| } |
| } |
| |
| static void *sym_get_data_by_offset(const struct elf_info *info, |
| unsigned int secindex, unsigned long offset) |
| { |
| Elf_Shdr *sechdr = &info->sechdrs[secindex]; |
| |
| if (info->hdr->e_type != ET_REL) |
| offset -= sechdr->sh_addr; |
| |
| return (void *)info->hdr + sechdr->sh_offset + offset; |
| } |
| |
| static void *sym_get_data(const struct elf_info *info, const Elf_Sym *sym) |
| { |
| return sym_get_data_by_offset(info, get_secindex(info, sym), |
| sym->st_value); |
| } |
| |
| static const char *sech_name(const struct elf_info *info, Elf_Shdr *sechdr) |
| { |
| return sym_get_data_by_offset(info, info->secindex_strings, |
| sechdr->sh_name); |
| } |
| |
| static const char *sec_name(const struct elf_info *info, int secindex) |
| { |
| return sech_name(info, &info->sechdrs[secindex]); |
| } |
| |
| #define strstarts(str, prefix) (strncmp(str, prefix, strlen(prefix)) == 0) |
| |
| static void sym_update_namespace(const char *symname, const char *namespace) |
| { |
| struct symbol *s = find_symbol(symname); |
| |
| /* |
| * That symbol should have been created earlier and thus this is |
| * actually an assertion. |
| */ |
| if (!s) { |
| error("Could not update namespace(%s) for symbol %s\n", |
| namespace, symname); |
| return; |
| } |
| |
| free(s->namespace); |
| s->namespace = namespace[0] ? NOFAIL(strdup(namespace)) : NULL; |
| } |
| |
| static struct symbol *sym_add_exported(const char *name, struct module *mod, |
| bool gpl_only) |
| { |
| struct symbol *s = find_symbol(name); |
| |
| if (s && (!external_module || s->module->is_vmlinux || s->module == mod)) { |
| error("%s: '%s' exported twice. Previous export was in %s%s\n", |
| mod->name, name, s->module->name, |
| s->module->is_vmlinux ? "" : ".ko"); |
| } |
| |
| s = alloc_symbol(name); |
| s->module = mod; |
| s->is_gpl_only = gpl_only; |
| list_add_tail(&s->list, &mod->exported_symbols); |
| hash_add_symbol(s); |
| |
| return s; |
| } |
| |
| static void sym_set_crc(struct symbol *sym, unsigned int crc) |
| { |
| sym->crc = crc; |
| sym->crc_valid = true; |
| } |
| |
| static void *grab_file(const char *filename, size_t *size) |
| { |
| struct stat st; |
| void *map = MAP_FAILED; |
| int fd; |
| |
| fd = open(filename, O_RDONLY); |
| if (fd < 0) |
| return NULL; |
| if (fstat(fd, &st)) |
| goto failed; |
| |
| *size = st.st_size; |
| map = mmap(NULL, *size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0); |
| |
| failed: |
| close(fd); |
| if (map == MAP_FAILED) |
| return NULL; |
| return map; |
| } |
| |
| static void release_file(void *file, size_t size) |
| { |
| munmap(file, size); |
| } |
| |
| static int parse_elf(struct elf_info *info, const char *filename) |
| { |
| unsigned int i; |
| Elf_Ehdr *hdr; |
| Elf_Shdr *sechdrs; |
| Elf_Sym *sym; |
| const char *secstrings; |
| unsigned int symtab_idx = ~0U, symtab_shndx_idx = ~0U; |
| |
| hdr = grab_file(filename, &info->size); |
| if (!hdr) { |
| if (ignore_missing_files) { |
| fprintf(stderr, "%s: %s (ignored)\n", filename, |
| strerror(errno)); |
| return 0; |
| } |
| perror(filename); |
| exit(1); |
| } |
| info->hdr = hdr; |
| if (info->size < sizeof(*hdr)) { |
| /* file too small, assume this is an empty .o file */ |
| return 0; |
| } |
| /* Is this a valid ELF file? */ |
| if ((hdr->e_ident[EI_MAG0] != ELFMAG0) || |
| (hdr->e_ident[EI_MAG1] != ELFMAG1) || |
| (hdr->e_ident[EI_MAG2] != ELFMAG2) || |
| (hdr->e_ident[EI_MAG3] != ELFMAG3)) { |
| /* Not an ELF file - silently ignore it */ |
| return 0; |
| } |
| /* Fix endianness in ELF header */ |
| hdr->e_type = TO_NATIVE(hdr->e_type); |
| hdr->e_machine = TO_NATIVE(hdr->e_machine); |
| hdr->e_version = TO_NATIVE(hdr->e_version); |
| hdr->e_entry = TO_NATIVE(hdr->e_entry); |
| hdr->e_phoff = TO_NATIVE(hdr->e_phoff); |
| hdr->e_shoff = TO_NATIVE(hdr->e_shoff); |
| hdr->e_flags = TO_NATIVE(hdr->e_flags); |
| hdr->e_ehsize = TO_NATIVE(hdr->e_ehsize); |
| hdr->e_phentsize = TO_NATIVE(hdr->e_phentsize); |
| hdr->e_phnum = TO_NATIVE(hdr->e_phnum); |
| hdr->e_shentsize = TO_NATIVE(hdr->e_shentsize); |
| hdr->e_shnum = TO_NATIVE(hdr->e_shnum); |
| hdr->e_shstrndx = TO_NATIVE(hdr->e_shstrndx); |
| sechdrs = (void *)hdr + hdr->e_shoff; |
| info->sechdrs = sechdrs; |
| |
| /* Check if file offset is correct */ |
| if (hdr->e_shoff > info->size) { |
| fatal("section header offset=%lu in file '%s' is bigger than filesize=%zu\n", |
| (unsigned long)hdr->e_shoff, filename, info->size); |
| return 0; |
| } |
| |
| if (hdr->e_shnum == SHN_UNDEF) { |
| /* |
| * There are more than 64k sections, |
| * read count from .sh_size. |
| */ |
| info->num_sections = TO_NATIVE(sechdrs[0].sh_size); |
| } |
| else { |
| info->num_sections = hdr->e_shnum; |
| } |
| if (hdr->e_shstrndx == SHN_XINDEX) { |
| info->secindex_strings = TO_NATIVE(sechdrs[0].sh_link); |
| } |
| else { |
| info->secindex_strings = hdr->e_shstrndx; |
| } |
| |
| /* Fix endianness in section headers */ |
| for (i = 0; i < info->num_sections; i++) { |
| sechdrs[i].sh_name = TO_NATIVE(sechdrs[i].sh_name); |
| sechdrs[i].sh_type = TO_NATIVE(sechdrs[i].sh_type); |
| sechdrs[i].sh_flags = TO_NATIVE(sechdrs[i].sh_flags); |
| sechdrs[i].sh_addr = TO_NATIVE(sechdrs[i].sh_addr); |
| sechdrs[i].sh_offset = TO_NATIVE(sechdrs[i].sh_offset); |
| sechdrs[i].sh_size = TO_NATIVE(sechdrs[i].sh_size); |
| sechdrs[i].sh_link = TO_NATIVE(sechdrs[i].sh_link); |
| sechdrs[i].sh_info = TO_NATIVE(sechdrs[i].sh_info); |
| sechdrs[i].sh_addralign = TO_NATIVE(sechdrs[i].sh_addralign); |
| sechdrs[i].sh_entsize = TO_NATIVE(sechdrs[i].sh_entsize); |
| } |
| /* Find symbol table. */ |
| secstrings = (void *)hdr + sechdrs[info->secindex_strings].sh_offset; |
| for (i = 1; i < info->num_sections; i++) { |
| const char *secname; |
| int nobits = sechdrs[i].sh_type == SHT_NOBITS; |
| |
| if (!nobits && sechdrs[i].sh_offset > info->size) { |
| fatal("%s is truncated. sechdrs[i].sh_offset=%lu > " |
| "sizeof(*hrd)=%zu\n", filename, |
| (unsigned long)sechdrs[i].sh_offset, |
| sizeof(*hdr)); |
| return 0; |
| } |
| secname = secstrings + sechdrs[i].sh_name; |
| if (strcmp(secname, ".modinfo") == 0) { |
| if (nobits) |
| fatal("%s has NOBITS .modinfo\n", filename); |
| info->modinfo = (void *)hdr + sechdrs[i].sh_offset; |
| info->modinfo_len = sechdrs[i].sh_size; |
| } |
| |
| if (sechdrs[i].sh_type == SHT_SYMTAB) { |
| unsigned int sh_link_idx; |
| symtab_idx = i; |
| info->symtab_start = (void *)hdr + |
| sechdrs[i].sh_offset; |
| info->symtab_stop = (void *)hdr + |
| sechdrs[i].sh_offset + sechdrs[i].sh_size; |
| sh_link_idx = sechdrs[i].sh_link; |
| info->strtab = (void *)hdr + |
| sechdrs[sh_link_idx].sh_offset; |
| } |
| |
| /* 32bit section no. table? ("more than 64k sections") */ |
| if (sechdrs[i].sh_type == SHT_SYMTAB_SHNDX) { |
| symtab_shndx_idx = i; |
| info->symtab_shndx_start = (void *)hdr + |
| sechdrs[i].sh_offset; |
| info->symtab_shndx_stop = (void *)hdr + |
| sechdrs[i].sh_offset + sechdrs[i].sh_size; |
| } |
| } |
| if (!info->symtab_start) |
| fatal("%s has no symtab?\n", filename); |
| |
| /* Fix endianness in symbols */ |
| for (sym = info->symtab_start; sym < info->symtab_stop; sym++) { |
| sym->st_shndx = TO_NATIVE(sym->st_shndx); |
| sym->st_name = TO_NATIVE(sym->st_name); |
| sym->st_value = TO_NATIVE(sym->st_value); |
| sym->st_size = TO_NATIVE(sym->st_size); |
| } |
| |
| if (symtab_shndx_idx != ~0U) { |
| Elf32_Word *p; |
| if (symtab_idx != sechdrs[symtab_shndx_idx].sh_link) |
| fatal("%s: SYMTAB_SHNDX has bad sh_link: %u!=%u\n", |
| filename, sechdrs[symtab_shndx_idx].sh_link, |
| symtab_idx); |
| /* Fix endianness */ |
| for (p = info->symtab_shndx_start; p < info->symtab_shndx_stop; |
| p++) |
| *p = TO_NATIVE(*p); |
| } |
| |
| return 1; |
| } |
| |
| static void parse_elf_finish(struct elf_info *info) |
| { |
| release_file(info->hdr, info->size); |
| } |
| |
| static int ignore_undef_symbol(struct elf_info *info, const char *symname) |
| { |
| /* ignore __this_module, it will be resolved shortly */ |
| if (strcmp(symname, "__this_module") == 0) |
| return 1; |
| /* ignore global offset table */ |
| if (strcmp(symname, "_GLOBAL_OFFSET_TABLE_") == 0) |
| return 1; |
| if (info->hdr->e_machine == EM_PPC) |
| /* Special register function linked on all modules during final link of .ko */ |
| if (strstarts(symname, "_restgpr_") || |
| strstarts(symname, "_savegpr_") || |
| strstarts(symname, "_rest32gpr_") || |
| strstarts(symname, "_save32gpr_") || |
| strstarts(symname, "_restvr_") || |
| strstarts(symname, "_savevr_")) |
| return 1; |
| if (info->hdr->e_machine == EM_PPC64) |
| /* Special register function linked on all modules during final link of .ko */ |
| if (strstarts(symname, "_restgpr0_") || |
| strstarts(symname, "_savegpr0_") || |
| strstarts(symname, "_restvr_") || |
| strstarts(symname, "_savevr_") || |
| strcmp(symname, ".TOC.") == 0) |
| return 1; |
| |
| if (info->hdr->e_machine == EM_S390) |
| /* Expoline thunks are linked on all kernel modules during final link of .ko */ |
| if (strstarts(symname, "__s390_indirect_jump_r")) |
| return 1; |
| /* Do not ignore this symbol */ |
| return 0; |
| } |
| |
| static void handle_symbol(struct module *mod, struct elf_info *info, |
| const Elf_Sym *sym, const char *symname) |
| { |
| switch (sym->st_shndx) { |
| case SHN_COMMON: |
| if (strstarts(symname, "__gnu_lto_")) { |
| /* Should warn here, but modpost runs before the linker */ |
| } else |
| warn("\"%s\" [%s] is COMMON symbol\n", symname, mod->name); |
| break; |
| case SHN_UNDEF: |
| /* undefined symbol */ |
| if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL && |
| ELF_ST_BIND(sym->st_info) != STB_WEAK) |
| break; |
| if (ignore_undef_symbol(info, symname)) |
| break; |
| if (info->hdr->e_machine == EM_SPARC || |
| info->hdr->e_machine == EM_SPARCV9) { |
| /* Ignore register directives. */ |
| if (ELF_ST_TYPE(sym->st_info) == STT_SPARC_REGISTER) |
| break; |
| if (symname[0] == '.') { |
| char *munged = NOFAIL(strdup(symname)); |
| munged[0] = '_'; |
| munged[1] = toupper(munged[1]); |
| symname = munged; |
| } |
| } |
| |
| sym_add_unresolved(symname, mod, |
| ELF_ST_BIND(sym->st_info) == STB_WEAK); |
| break; |
| default: |
| /* All exported symbols */ |
| if (strstarts(symname, "__ksymtab_")) { |
| const char *name, *secname; |
| |
| name = symname + strlen("__ksymtab_"); |
| secname = sec_name(info, get_secindex(info, sym)); |
| |
| if (strstarts(secname, "___ksymtab_gpl+")) |
| sym_add_exported(name, mod, true); |
| else if (strstarts(secname, "___ksymtab+")) |
| sym_add_exported(name, mod, false); |
| } |
| if (strcmp(symname, "init_module") == 0) |
| mod->has_init = true; |
| if (strcmp(symname, "cleanup_module") == 0) |
| mod->has_cleanup = true; |
| break; |
| } |
| } |
| |
| /** |
| * Parse tag=value strings from .modinfo section |
| **/ |
| static char *next_string(char *string, unsigned long *secsize) |
| { |
| /* Skip non-zero chars */ |
| while (string[0]) { |
| string++; |
| if ((*secsize)-- <= 1) |
| return NULL; |
| } |
| |
| /* Skip any zero padding. */ |
| while (!string[0]) { |
| string++; |
| if ((*secsize)-- <= 1) |
| return NULL; |
| } |
| return string; |
| } |
| |
| static char *get_next_modinfo(struct elf_info *info, const char *tag, |
| char *prev) |
| { |
| char *p; |
| unsigned int taglen = strlen(tag); |
| char *modinfo = info->modinfo; |
| unsigned long size = info->modinfo_len; |
| |
| if (prev) { |
| size -= prev - modinfo; |
| modinfo = next_string(prev, &size); |
| } |
| |
| for (p = modinfo; p; p = next_string(p, &size)) { |
| if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=') |
| return p + taglen + 1; |
| } |
| return NULL; |
| } |
| |
| static char *get_modinfo(struct elf_info *info, const char *tag) |
| |
| { |
| return get_next_modinfo(info, tag, NULL); |
| } |
| |
| static const char *sym_name(struct elf_info *elf, Elf_Sym *sym) |
| { |
| if (sym) |
| return elf->strtab + sym->st_name; |
| else |
| return "(unknown)"; |
| } |
| |
| /* |
| * Check whether the 'string' argument matches one of the 'patterns', |
| * an array of shell wildcard patterns (glob). |
| * |
| * Return true is there is a match. |
| */ |
| static bool match(const char *string, const char *const patterns[]) |
| { |
| const char *pattern; |
| |
| while ((pattern = *patterns++)) { |
| if (!fnmatch(pattern, string, 0)) |
| return true; |
| } |
| |
| return false; |
| } |
| |
| /* sections that we do not want to do full section mismatch check on */ |
| static const char *const section_white_list[] = |
| { |
| ".comment*", |
| ".debug*", |
| ".cranges", /* sh64 */ |
| ".zdebug*", /* Compressed debug sections. */ |
| ".GCC.command.line", /* record-gcc-switches */ |
| ".mdebug*", /* alpha, score, mips etc. */ |
| ".pdr", /* alpha, score, mips etc. */ |
| ".stab*", |
| ".note*", |
| ".got*", |
| ".toc*", |
| ".xt.prop", /* xtensa */ |
| ".xt.lit", /* xtensa */ |
| ".arcextmap*", /* arc */ |
| ".gnu.linkonce.arcext*", /* arc : modules */ |
| ".cmem*", /* EZchip */ |
| ".fmt_slot*", /* EZchip */ |
| ".gnu.lto*", |
| ".discard.*", |
| NULL |
| }; |
| |
| /* |
| * This is used to find sections missing the SHF_ALLOC flag. |
| * The cause of this is often a section specified in assembler |
| * without "ax" / "aw". |
| */ |
| static void check_section(const char *modname, struct elf_info *elf, |
| Elf_Shdr *sechdr) |
| { |
| const char *sec = sech_name(elf, sechdr); |
| |
| if (sechdr->sh_type == SHT_PROGBITS && |
| !(sechdr->sh_flags & SHF_ALLOC) && |
| !match(sec, section_white_list)) { |
| warn("%s (%s): unexpected non-allocatable section.\n" |
| "Did you forget to use \"ax\"/\"aw\" in a .S file?\n" |
| "Note that for example <linux/init.h> contains\n" |
| "section definitions for use in .S files.\n\n", |
| modname, sec); |
| } |
| } |
| |
| |
| |
| #define ALL_INIT_DATA_SECTIONS \ |
| ".init.setup", ".init.rodata", ".meminit.rodata", \ |
| ".init.data", ".meminit.data" |
| #define ALL_EXIT_DATA_SECTIONS \ |
| ".exit.data", ".memexit.data" |
| |
| #define ALL_INIT_TEXT_SECTIONS \ |
| ".init.text", ".meminit.text" |
| #define ALL_EXIT_TEXT_SECTIONS \ |
| ".exit.text", ".memexit.text" |
| |
| #define ALL_PCI_INIT_SECTIONS \ |
| ".pci_fixup_early", ".pci_fixup_header", ".pci_fixup_final", \ |
| ".pci_fixup_enable", ".pci_fixup_resume", \ |
| ".pci_fixup_resume_early", ".pci_fixup_suspend" |
| |
| #define ALL_XXXINIT_SECTIONS MEM_INIT_SECTIONS |
| #define ALL_XXXEXIT_SECTIONS MEM_EXIT_SECTIONS |
| |
| #define ALL_INIT_SECTIONS INIT_SECTIONS, ALL_XXXINIT_SECTIONS |
| #define ALL_EXIT_SECTIONS EXIT_SECTIONS, ALL_XXXEXIT_SECTIONS |
| |
| #define DATA_SECTIONS ".data", ".data.rel" |
| #define TEXT_SECTIONS ".text", ".text.unlikely", ".sched.text", \ |
| ".kprobes.text", ".cpuidle.text", ".noinstr.text" |
| #define OTHER_TEXT_SECTIONS ".ref.text", ".head.text", ".spinlock.text", \ |
| ".fixup", ".entry.text", ".exception.text", ".text.*", \ |
| ".coldtext", ".softirqentry.text" |
| |
| #define INIT_SECTIONS ".init.*" |
| #define MEM_INIT_SECTIONS ".meminit.*" |
| |
| #define EXIT_SECTIONS ".exit.*" |
| #define MEM_EXIT_SECTIONS ".memexit.*" |
| |
| #define ALL_TEXT_SECTIONS ALL_INIT_TEXT_SECTIONS, ALL_EXIT_TEXT_SECTIONS, \ |
| TEXT_SECTIONS, OTHER_TEXT_SECTIONS |
| |
| /* init data sections */ |
| static const char *const init_data_sections[] = |
| { ALL_INIT_DATA_SECTIONS, NULL }; |
| |
| /* all init sections */ |
| static const char *const init_sections[] = { ALL_INIT_SECTIONS, NULL }; |
| |
| /* All init and exit sections (code + data) */ |
| static const char *const init_exit_sections[] = |
| {ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS, NULL }; |
| |
| /* all text sections */ |
| static const char *const text_sections[] = { ALL_TEXT_SECTIONS, NULL }; |
| |
| /* data section */ |
| static const char *const data_sections[] = { DATA_SECTIONS, NULL }; |
| |
| |
| /* symbols in .data that may refer to init/exit sections */ |
| #define DEFAULT_SYMBOL_WHITE_LIST \ |
| "*driver", \ |
| "*_template", /* scsi uses *_template a lot */ \ |
| "*_timer", /* arm uses ops structures named _timer a lot */ \ |
| "*_sht", /* scsi also used *_sht to some extent */ \ |
| "*_ops", \ |
| "*_probe", \ |
| "*_probe_one", \ |
| "*_console" |
| |
| static const char *const head_sections[] = { ".head.text*", NULL }; |
| static const char *const linker_symbols[] = |
| { "__init_begin", "_sinittext", "_einittext", NULL }; |
| static const char *const optim_symbols[] = { "*.constprop.*", NULL }; |
| |
| enum mismatch { |
| TEXT_TO_ANY_INIT, |
| DATA_TO_ANY_INIT, |
| TEXT_TO_ANY_EXIT, |
| DATA_TO_ANY_EXIT, |
| XXXINIT_TO_SOME_INIT, |
| XXXEXIT_TO_SOME_EXIT, |
| ANY_INIT_TO_ANY_EXIT, |
| ANY_EXIT_TO_ANY_INIT, |
| EXPORT_TO_INIT_EXIT, |
| EXTABLE_TO_NON_TEXT, |
| }; |
| |
| /** |
| * Describe how to match sections on different criteria: |
| * |
| * @fromsec: Array of sections to be matched. |
| * |
| * @bad_tosec: Relocations applied to a section in @fromsec to a section in |
| * this array is forbidden (black-list). Can be empty. |
| * |
| * @good_tosec: Relocations applied to a section in @fromsec must be |
| * targeting sections in this array (white-list). Can be empty. |
| * |
| * @mismatch: Type of mismatch. |
| * |
| * @symbol_white_list: Do not match a relocation to a symbol in this list |
| * even if it is targeting a section in @bad_to_sec. |
| * |
| * @handler: Specific handler to call when a match is found. If NULL, |
| * default_mismatch_handler() will be called. |
| * |
| */ |
| struct sectioncheck { |
| const char *fromsec[20]; |
| const char *bad_tosec[20]; |
| const char *good_tosec[20]; |
| enum mismatch mismatch; |
| const char *symbol_white_list[20]; |
| void (*handler)(const char *modname, struct elf_info *elf, |
| const struct sectioncheck* const mismatch, |
| Elf_Rela *r, Elf_Sym *sym, const char *fromsec); |
| |
| }; |
| |
| static void extable_mismatch_handler(const char *modname, struct elf_info *elf, |
| const struct sectioncheck* const mismatch, |
| Elf_Rela *r, Elf_Sym *sym, |
| const char *fromsec); |
| |
| static const struct sectioncheck sectioncheck[] = { |
| /* Do not reference init/exit code/data from |
| * normal code and data |
| */ |
| { |
| .fromsec = { TEXT_SECTIONS, NULL }, |
| .bad_tosec = { ALL_INIT_SECTIONS, NULL }, |
| .mismatch = TEXT_TO_ANY_INIT, |
| .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, |
| }, |
| { |
| .fromsec = { DATA_SECTIONS, NULL }, |
| .bad_tosec = { ALL_XXXINIT_SECTIONS, NULL }, |
| .mismatch = DATA_TO_ANY_INIT, |
| .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, |
| }, |
| { |
| .fromsec = { DATA_SECTIONS, NULL }, |
| .bad_tosec = { INIT_SECTIONS, NULL }, |
| .mismatch = DATA_TO_ANY_INIT, |
| .symbol_white_list = { |
| "*_template", "*_timer", "*_sht", "*_ops", |
| "*_probe", "*_probe_one", "*_console", NULL |
| }, |
| }, |
| { |
| .fromsec = { TEXT_SECTIONS, NULL }, |
| .bad_tosec = { ALL_EXIT_SECTIONS, NULL }, |
| .mismatch = TEXT_TO_ANY_EXIT, |
| .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, |
| }, |
| { |
| .fromsec = { DATA_SECTIONS, NULL }, |
| .bad_tosec = { ALL_EXIT_SECTIONS, NULL }, |
| .mismatch = DATA_TO_ANY_EXIT, |
| .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, |
| }, |
| /* Do not reference init code/data from meminit code/data */ |
| { |
| .fromsec = { ALL_XXXINIT_SECTIONS, NULL }, |
| .bad_tosec = { INIT_SECTIONS, NULL }, |
| .mismatch = XXXINIT_TO_SOME_INIT, |
| .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, |
| }, |
| /* Do not reference exit code/data from memexit code/data */ |
| { |
| .fromsec = { ALL_XXXEXIT_SECTIONS, NULL }, |
| .bad_tosec = { EXIT_SECTIONS, NULL }, |
| .mismatch = XXXEXIT_TO_SOME_EXIT, |
| .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, |
| }, |
| /* Do not use exit code/data from init code */ |
| { |
| .fromsec = { ALL_INIT_SECTIONS, NULL }, |
| .bad_tosec = { ALL_EXIT_SECTIONS, NULL }, |
| .mismatch = ANY_INIT_TO_ANY_EXIT, |
| .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, |
| }, |
| /* Do not use init code/data from exit code */ |
| { |
| .fromsec = { ALL_EXIT_SECTIONS, NULL }, |
| .bad_tosec = { ALL_INIT_SECTIONS, NULL }, |
| .mismatch = ANY_EXIT_TO_ANY_INIT, |
| .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, |
| }, |
| { |
| .fromsec = { ALL_PCI_INIT_SECTIONS, NULL }, |
| .bad_tosec = { INIT_SECTIONS, NULL }, |
| .mismatch = ANY_INIT_TO_ANY_EXIT, |
| .symbol_white_list = { NULL }, |
| }, |
| /* Do not export init/exit functions or data */ |
| { |
| .fromsec = { "__ksymtab*", NULL }, |
| .bad_tosec = { INIT_SECTIONS, EXIT_SECTIONS, NULL }, |
| .mismatch = EXPORT_TO_INIT_EXIT, |
| .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, |
| }, |
| { |
| .fromsec = { "__ex_table", NULL }, |
| /* If you're adding any new black-listed sections in here, consider |
| * adding a special 'printer' for them in scripts/check_extable. |
| */ |
| .bad_tosec = { ".altinstr_replacement", NULL }, |
| .good_tosec = {ALL_TEXT_SECTIONS , NULL}, |
| .mismatch = EXTABLE_TO_NON_TEXT, |
| .handler = extable_mismatch_handler, |
| } |
| }; |
| |
| static const struct sectioncheck *section_mismatch( |
| const char *fromsec, const char *tosec) |
| { |
| int i; |
| |
| /* |
| * The target section could be the SHT_NUL section when we're |
| * handling relocations to un-resolved symbols, trying to match it |
| * doesn't make much sense and causes build failures on parisc |
| * architectures. |
| */ |
| if (*tosec == '\0') |
| return NULL; |
| |
| for (i = 0; i < ARRAY_SIZE(sectioncheck); i++) { |
| const struct sectioncheck *check = §ioncheck[i]; |
| |
| if (match(fromsec, check->fromsec)) { |
| if (check->bad_tosec[0] && match(tosec, check->bad_tosec)) |
| return check; |
| if (check->good_tosec[0] && !match(tosec, check->good_tosec)) |
| return check; |
| } |
| } |
| return NULL; |
| } |
| |
| /** |
| * Whitelist to allow certain references to pass with no warning. |
| * |
| * Pattern 1: |
| * If a module parameter is declared __initdata and permissions=0 |
| * then this is legal despite the warning generated. |
| * We cannot see value of permissions here, so just ignore |
| * this pattern. |
| * The pattern is identified by: |
| * tosec = .init.data |
| * fromsec = .data* |
| * atsym =__param* |
| * |
| * Pattern 1a: |
| * module_param_call() ops can refer to __init set function if permissions=0 |
| * The pattern is identified by: |
| * tosec = .init.text |
| * fromsec = .data* |
| * atsym = __param_ops_* |
| * |
| * Pattern 2: |
| * Many drivers utilise a *driver container with references to |
| * add, remove, probe functions etc. |
| * the pattern is identified by: |
| * tosec = init or exit section |
| * fromsec = data section |
| * atsym = *driver, *_template, *_sht, *_ops, *_probe, |
| * *probe_one, *_console, *_timer |
| * |
| * Pattern 3: |
| * Whitelist all references from .head.text to any init section |
| * |
| * Pattern 4: |
| * Some symbols belong to init section but still it is ok to reference |
| * these from non-init sections as these symbols don't have any memory |
| * allocated for them and symbol address and value are same. So even |
| * if init section is freed, its ok to reference those symbols. |
| * For ex. symbols marking the init section boundaries. |
| * This pattern is identified by |
| * refsymname = __init_begin, _sinittext, _einittext |
| * |
| * Pattern 5: |
| * GCC may optimize static inlines when fed constant arg(s) resulting |
| * in functions like cpumask_empty() -- generating an associated symbol |
| * cpumask_empty.constprop.3 that appears in the audit. If the const that |
| * is passed in comes from __init, like say nmi_ipi_mask, we get a |
| * meaningless section warning. May need to add isra symbols too... |
| * This pattern is identified by |
| * tosec = init section |
| * fromsec = text section |
| * refsymname = *.constprop.* |
| * |
| * Pattern 6: |
| * Hide section mismatch warnings for ELF local symbols. The goal |
| * is to eliminate false positive modpost warnings caused by |
| * compiler-generated ELF local symbol names such as ".LANCHOR1". |
| * Autogenerated symbol names bypass modpost's "Pattern 2" |
| * whitelisting, which relies on pattern-matching against symbol |
| * names to work. (One situation where gcc can autogenerate ELF |
| * local symbols is when "-fsection-anchors" is used.) |
| **/ |
| static int secref_whitelist(const struct sectioncheck *mismatch, |
| const char *fromsec, const char *fromsym, |
| const char *tosec, const char *tosym) |
| { |
| /* Check for pattern 1 */ |
| if (match(tosec, init_data_sections) && |
| match(fromsec, data_sections) && |
| strstarts(fromsym, "__param")) |
| return 0; |
| |
| /* Check for pattern 1a */ |
| if (strcmp(tosec, ".init.text") == 0 && |
| match(fromsec, data_sections) && |
| strstarts(fromsym, "__param_ops_")) |
| return 0; |
| |
| /* Check for pattern 2 */ |
| if (match(tosec, init_exit_sections) && |
| match(fromsec, data_sections) && |
| match(fromsym, mismatch->symbol_white_list)) |
| return 0; |
| |
| /* Check for pattern 3 */ |
| if (match(fromsec, head_sections) && |
| match(tosec, init_sections)) |
| return 0; |
| |
| /* Check for pattern 4 */ |
| if (match(tosym, linker_symbols)) |
| return 0; |
| |
| /* Check for pattern 5 */ |
| if (match(fromsec, text_sections) && |
| match(tosec, init_sections) && |
| match(fromsym, optim_symbols)) |
| return 0; |
| |
| /* Check for pattern 6 */ |
| if (strstarts(fromsym, ".L")) |
| return 0; |
| |
| return 1; |
| } |
| |
| static inline int is_arm_mapping_symbol(const char *str) |
| { |
| return str[0] == '$' && |
| (str[1] == 'a' || str[1] == 'd' || str[1] == 't' || str[1] == 'x') |
| && (str[2] == '\0' || str[2] == '.'); |
| } |
| |
| /* |
| * If there's no name there, ignore it; likewise, ignore it if it's |
| * one of the magic symbols emitted used by current ARM tools. |
| * |
| * Otherwise if find_symbols_between() returns those symbols, they'll |
| * fail the whitelist tests and cause lots of false alarms ... fixable |
| * only by merging __exit and __init sections into __text, bloating |
| * the kernel (which is especially evil on embedded platforms). |
| */ |
| static inline int is_valid_name(struct elf_info *elf, Elf_Sym *sym) |
| { |
| const char *name = elf->strtab + sym->st_name; |
| |
| if (!name || !strlen(name)) |
| return 0; |
| return !is_arm_mapping_symbol(name); |
| } |
| |
| /** |
| * Find symbol based on relocation record info. |
| * In some cases the symbol supplied is a valid symbol so |
| * return refsym. If st_name != 0 we assume this is a valid symbol. |
| * In other cases the symbol needs to be looked up in the symbol table |
| * based on section and address. |
| * **/ |
| static Elf_Sym *find_elf_symbol(struct elf_info *elf, Elf64_Sword addr, |
| Elf_Sym *relsym) |
| { |
| Elf_Sym *sym; |
| Elf_Sym *near = NULL; |
| Elf64_Sword distance = 20; |
| Elf64_Sword d; |
| unsigned int relsym_secindex; |
| |
| if (relsym->st_name != 0) |
| return relsym; |
| |
| relsym_secindex = get_secindex(elf, relsym); |
| for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) { |
| if (get_secindex(elf, sym) != relsym_secindex) |
| continue; |
| if (ELF_ST_TYPE(sym->st_info) == STT_SECTION) |
| continue; |
| if (!is_valid_name(elf, sym)) |
| continue; |
| if (sym->st_value == addr) |
| return sym; |
| /* Find a symbol nearby - addr are maybe negative */ |
| d = sym->st_value - addr; |
| if (d < 0) |
| d = addr - sym->st_value; |
| if (d < distance) { |
| distance = d; |
| near = sym; |
| } |
| } |
| /* We need a close match */ |
| if (distance < 20) |
| return near; |
| else |
| return NULL; |
| } |
| |
| /* |
| * Find symbols before or equal addr and after addr - in the section sec. |
| * If we find two symbols with equal offset prefer one with a valid name. |
| * The ELF format may have a better way to detect what type of symbol |
| * it is, but this works for now. |
| **/ |
| static Elf_Sym *find_elf_symbol2(struct elf_info *elf, Elf_Addr addr, |
| const char *sec) |
| { |
| Elf_Sym *sym; |
| Elf_Sym *near = NULL; |
| Elf_Addr distance = ~0; |
| |
| for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) { |
| const char *symsec; |
| |
| if (is_shndx_special(sym->st_shndx)) |
| continue; |
| symsec = sec_name(elf, get_secindex(elf, sym)); |
| if (strcmp(symsec, sec) != 0) |
| continue; |
| if (!is_valid_name(elf, sym)) |
| continue; |
| if (sym->st_value <= addr && addr - sym->st_value <= distance) { |
| distance = addr - sym->st_value; |
| near = sym; |
| } |
| } |
| return near; |
| } |
| |
| /* |
| * Convert a section name to the function/data attribute |
| * .init.text => __init |
| * .memexitconst => __memconst |
| * etc. |
| * |
| * The memory of returned value has been allocated on a heap. The user of this |
| * method should free it after usage. |
| */ |
| static char *sec2annotation(const char *s) |
| { |
| if (match(s, init_exit_sections)) { |
| char *p = NOFAIL(malloc(20)); |
| char *r = p; |
| |
| *p++ = '_'; |
| *p++ = '_'; |
| if (*s == '.') |
| s++; |
| while (*s && *s != '.') |
| *p++ = *s++; |
| *p = '\0'; |
| if (*s == '.') |
| s++; |
| if (strstr(s, "rodata") != NULL) |
| strcat(p, "const "); |
| else if (strstr(s, "data") != NULL) |
| strcat(p, "data "); |
| else |
| strcat(p, " "); |
| return r; |
| } else { |
| return NOFAIL(strdup("")); |
| } |
| } |
| |
| static int is_function(Elf_Sym *sym) |
| { |
| if (sym) |
| return ELF_ST_TYPE(sym->st_info) == STT_FUNC; |
| else |
| return -1; |
| } |
| |
| static void print_section_list(const char * const list[20]) |
| { |
| const char *const *s = list; |
| |
| while (*s) { |
| fprintf(stderr, "%s", *s); |
| s++; |
| if (*s) |
| fprintf(stderr, ", "); |
| } |
| fprintf(stderr, "\n"); |
| } |
| |
| static inline void get_pretty_name(int is_func, const char** name, const char** name_p) |
| { |
| switch (is_func) { |
| case 0: *name = "variable"; *name_p = ""; break; |
| case 1: *name = "function"; *name_p = "()"; break; |
| default: *name = "(unknown reference)"; *name_p = ""; break; |
| } |
| } |
| |
| /* |
| * Print a warning about a section mismatch. |
| * Try to find symbols near it so user can find it. |
| * Check whitelist before warning - it may be a false positive. |
| */ |
| static void report_sec_mismatch(const char *modname, |
| const struct sectioncheck *mismatch, |
| const char *fromsec, |
| unsigned long long fromaddr, |
| const char *fromsym, |
| int from_is_func, |
| const char *tosec, const char *tosym, |
| int to_is_func) |
| { |
| const char *from, *from_p; |
| const char *to, *to_p; |
| char *prl_from; |
| char *prl_to; |
| |
| sec_mismatch_count++; |
| |
| get_pretty_name(from_is_func, &from, &from_p); |
| get_pretty_name(to_is_func, &to, &to_p); |
| |
| warn("%s(%s+0x%llx): Section mismatch in reference from the %s %s%s " |
| "to the %s %s:%s%s\n", |
| modname, fromsec, fromaddr, from, fromsym, from_p, to, tosec, |
| tosym, to_p); |
| |
| switch (mismatch->mismatch) { |
| case TEXT_TO_ANY_INIT: |
| prl_from = sec2annotation(fromsec); |
| prl_to = sec2annotation(tosec); |
| fprintf(stderr, |
| "The function %s%s() references\n" |
| "the %s %s%s%s.\n" |
| "This is often because %s lacks a %s\n" |
| "annotation or the annotation of %s is wrong.\n", |
| prl_from, fromsym, |
| to, prl_to, tosym, to_p, |
| fromsym, prl_to, tosym); |
| free(prl_from); |
| free(prl_to); |
| break; |
| case DATA_TO_ANY_INIT: { |
| prl_to = sec2annotation(tosec); |
| fprintf(stderr, |
| "The variable %s references\n" |
| "the %s %s%s%s\n" |
| "If the reference is valid then annotate the\n" |
| "variable with __init* or __refdata (see linux/init.h) " |
| "or name the variable:\n", |
| fromsym, to, prl_to, tosym, to_p); |
| print_section_list(mismatch->symbol_white_list); |
| free(prl_to); |
| break; |
| } |
| case TEXT_TO_ANY_EXIT: |
| prl_to = sec2annotation(tosec); |
| fprintf(stderr, |
| "The function %s() references a %s in an exit section.\n" |
| "Often the %s %s%s has valid usage outside the exit section\n" |
| "and the fix is to remove the %sannotation of %s.\n", |
| fromsym, to, to, tosym, to_p, prl_to, tosym); |
| free(prl_to); |
| break; |
| case DATA_TO_ANY_EXIT: { |
| prl_to = sec2annotation(tosec); |
| fprintf(stderr, |
| "The variable %s references\n" |
| "the %s %s%s%s\n" |
| "If the reference is valid then annotate the\n" |
| "variable with __exit* (see linux/init.h) or " |
| "name the variable:\n", |
| fromsym, to, prl_to, tosym, to_p); |
| print_section_list(mismatch->symbol_white_list); |
| free(prl_to); |
| break; |
| } |
| case XXXINIT_TO_SOME_INIT: |
| case XXXEXIT_TO_SOME_EXIT: |
| prl_from = sec2annotation(fromsec); |
| prl_to = sec2annotation(tosec); |
| fprintf(stderr, |
| "The %s %s%s%s references\n" |
| "a %s %s%s%s.\n" |
| "If %s is only used by %s then\n" |
| "annotate %s with a matching annotation.\n", |
| from, prl_from, fromsym, from_p, |
| to, prl_to, tosym, to_p, |
| tosym, fromsym, tosym); |
| free(prl_from); |
| free(prl_to); |
| break; |
| case ANY_INIT_TO_ANY_EXIT: |
| prl_from = sec2annotation(fromsec); |
| prl_to = sec2annotation(tosec); |
| fprintf(stderr, |
| "The %s %s%s%s references\n" |
| "a %s %s%s%s.\n" |
| "This is often seen when error handling " |
| "in the init function\n" |
| "uses functionality in the exit path.\n" |
| "The fix is often to remove the %sannotation of\n" |
| "%s%s so it may be used outside an exit section.\n", |
| from, prl_from, fromsym, from_p, |
| to, prl_to, tosym, to_p, |
| prl_to, tosym, to_p); |
| free(prl_from); |
| free(prl_to); |
| break; |
| case ANY_EXIT_TO_ANY_INIT: |
| prl_from = sec2annotation(fromsec); |
| prl_to = sec2annotation(tosec); |
| fprintf(stderr, |
| "The %s %s%s%s references\n" |
| "a %s %s%s%s.\n" |
| "This is often seen when error handling " |
| "in the exit function\n" |
| "uses functionality in the init path.\n" |
| "The fix is often to remove the %sannotation of\n" |
| "%s%s so it may be used outside an init section.\n", |
| from, prl_from, fromsym, from_p, |
| to, prl_to, tosym, to_p, |
| prl_to, tosym, to_p); |
| free(prl_from); |
| free(prl_to); |
| break; |
| case EXPORT_TO_INIT_EXIT: |
| prl_to = sec2annotation(tosec); |
| fprintf(stderr, |
| "The symbol %s is exported and annotated %s\n" |
| "Fix this by removing the %sannotation of %s " |
| "or drop the export.\n", |
| tosym, prl_to, prl_to, tosym); |
| free(prl_to); |
| break; |
| case EXTABLE_TO_NON_TEXT: |
| fatal("There's a special handler for this mismatch type, " |
| "we should never get here."); |
| break; |
| } |
| fprintf(stderr, "\n"); |
| } |
| |
| static void default_mismatch_handler(const char *modname, struct elf_info *elf, |
| const struct sectioncheck* const mismatch, |
| Elf_Rela *r, Elf_Sym *sym, const char *fromsec) |
| { |
| const char *tosec; |
| Elf_Sym *to; |
| Elf_Sym *from; |
| const char *tosym; |
| const char *fromsym; |
| |
| from = find_elf_symbol2(elf, r->r_offset, fromsec); |
| fromsym = sym_name(elf, from); |
| |
| if (strstarts(fromsym, "reference___initcall")) |
| return; |
| |
| tosec = sec_name(elf, get_secindex(elf, sym)); |
| to = find_elf_symbol(elf, r->r_addend, sym); |
| tosym = sym_name(elf, to); |
| |
| /* check whitelist - we may ignore it */ |
| if (secref_whitelist(mismatch, |
| fromsec, fromsym, tosec, tosym)) { |
| report_sec_mismatch(modname, mismatch, |
| fromsec, r->r_offset, fromsym, |
| is_function(from), tosec, tosym, |
| is_function(to)); |
| } |
| } |
| |
| static int is_executable_section(struct elf_info* elf, unsigned int section_index) |
| { |
| if (section_index > elf->num_sections) |
| fatal("section_index is outside elf->num_sections!\n"); |
| |
| return ((elf->sechdrs[section_index].sh_flags & SHF_EXECINSTR) == SHF_EXECINSTR); |
| } |
| |
| /* |
| * We rely on a gross hack in section_rel[a]() calling find_extable_entry_size() |
| * to know the sizeof(struct exception_table_entry) for the target architecture. |
| */ |
| static unsigned int extable_entry_size = 0; |
| static void find_extable_entry_size(const char* const sec, const Elf_Rela* r) |
| { |
| /* |
| * If we're currently checking the second relocation within __ex_table, |
| * that relocation offset tells us the offsetof(struct |
| * exception_table_entry, fixup) which is equal to sizeof(struct |
| * exception_table_entry) divided by two. We use that to our advantage |
| * since there's no portable way to get that size as every architecture |
| * seems to go with different sized types. Not pretty but better than |
| * hard-coding the size for every architecture.. |
| */ |
| if (!extable_entry_size) |
| extable_entry_size = r->r_offset * 2; |
| } |
| |
| static inline bool is_extable_fault_address(Elf_Rela *r) |
| { |
| /* |
| * extable_entry_size is only discovered after we've handled the |
| * _second_ relocation in __ex_table, so only abort when we're not |
| * handling the first reloc and extable_entry_size is zero. |
| */ |
| if (r->r_offset && extable_entry_size == 0) |
| fatal("extable_entry size hasn't been discovered!\n"); |
| |
| return ((r->r_offset == 0) || |
| (r->r_offset % extable_entry_size == 0)); |
| } |
| |
| #define is_second_extable_reloc(Start, Cur, Sec) \ |
| (((Cur) == (Start) + 1) && (strcmp("__ex_table", (Sec)) == 0)) |
| |
| static void report_extable_warnings(const char* modname, struct elf_info* elf, |
| const struct sectioncheck* const mismatch, |
| Elf_Rela* r, Elf_Sym* sym, |
| const char* fromsec, const char* tosec) |
| { |
| Elf_Sym* fromsym = find_elf_symbol2(elf, r->r_offset, fromsec); |
| const char* fromsym_name = sym_name(elf, fromsym); |
| Elf_Sym* tosym = find_elf_symbol(elf, r->r_addend, sym); |
| const char* tosym_name = sym_name(elf, tosym); |
| const char* from_pretty_name; |
| const char* from_pretty_name_p; |
| const char* to_pretty_name; |
| const char* to_pretty_name_p; |
| |
| get_pretty_name(is_function(fromsym), |
| &from_pretty_name, &from_pretty_name_p); |
| get_pretty_name(is_function(tosym), |
| &to_pretty_name, &to_pretty_name_p); |
| |
| warn("%s(%s+0x%lx): Section mismatch in reference" |
| " from the %s %s%s to the %s %s:%s%s\n", |
| modname, fromsec, (long)r->r_offset, from_pretty_name, |
| fromsym_name, from_pretty_name_p, |
| to_pretty_name, tosec, tosym_name, to_pretty_name_p); |
| |
| if (!match(tosec, mismatch->bad_tosec) && |
| is_executable_section(elf, get_secindex(elf, sym))) |
| fprintf(stderr, |
| "The relocation at %s+0x%lx references\n" |
| "section \"%s\" which is not in the list of\n" |
| "authorized sections. If you're adding a new section\n" |
| "and/or if this reference is valid, add \"%s\" to the\n" |
| "list of authorized sections to jump to on fault.\n" |
| "This can be achieved by adding \"%s\" to \n" |
| "OTHER_TEXT_SECTIONS in scripts/mod/modpost.c.\n", |
| fromsec, (long)r->r_offset, tosec, tosec, tosec); |
| } |
| |
| static void extable_mismatch_handler(const char* modname, struct elf_info *elf, |
| const struct sectioncheck* const mismatch, |
| Elf_Rela* r, Elf_Sym* sym, |
| const char *fromsec) |
| { |
| const char* tosec = sec_name(elf, get_secindex(elf, sym)); |
| |
| sec_mismatch_count++; |
| |
| report_extable_warnings(modname, elf, mismatch, r, sym, fromsec, tosec); |
| |
| if (match(tosec, mismatch->bad_tosec)) |
| fatal("The relocation at %s+0x%lx references\n" |
| "section \"%s\" which is black-listed.\n" |
| "Something is seriously wrong and should be fixed.\n" |
| "You might get more information about where this is\n" |
| "coming from by using scripts/check_extable.sh %s\n", |
| fromsec, (long)r->r_offset, tosec, modname); |
| else if (!is_executable_section(elf, get_secindex(elf, sym))) { |
| if (is_extable_fault_address(r)) |
| fatal("The relocation at %s+0x%lx references\n" |
| "section \"%s\" which is not executable, IOW\n" |
| "it is not possible for the kernel to fault\n" |
| "at that address. Something is seriously wrong\n" |
| "and should be fixed.\n", |
| fromsec, (long)r->r_offset, tosec); |
| else |
| fatal("The relocation at %s+0x%lx references\n" |
| "section \"%s\" which is not executable, IOW\n" |
| "the kernel will fault if it ever tries to\n" |
| "jump to it. Something is seriously wrong\n" |
| "and should be fixed.\n", |
| fromsec, (long)r->r_offset, tosec); |
| } |
| } |
| |
| static void check_section_mismatch(const char *modname, struct elf_info *elf, |
| Elf_Rela *r, Elf_Sym *sym, const char *fromsec) |
| { |
| const char *tosec = sec_name(elf, get_secindex(elf, sym)); |
| const struct sectioncheck *mismatch = section_mismatch(fromsec, tosec); |
| |
| if (mismatch) { |
| if (mismatch->handler) |
| mismatch->handler(modname, elf, mismatch, |
| r, sym, fromsec); |
| else |
| default_mismatch_handler(modname, elf, mismatch, |
| r, sym, fromsec); |
| } |
| } |
| |
| static unsigned int *reloc_location(struct elf_info *elf, |
| Elf_Shdr *sechdr, Elf_Rela *r) |
| { |
| return sym_get_data_by_offset(elf, sechdr->sh_info, r->r_offset); |
| } |
| |
| static int addend_386_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r) |
| { |
| unsigned int r_typ = ELF_R_TYPE(r->r_info); |
| unsigned int *location = reloc_location(elf, sechdr, r); |
| |
| switch (r_typ) { |
| case R_386_32: |
| r->r_addend = TO_NATIVE(*location); |
| break; |
| case R_386_PC32: |
| r->r_addend = TO_NATIVE(*location) + 4; |
| /* For CONFIG_RELOCATABLE=y */ |
| if (elf->hdr->e_type == ET_EXEC) |
| r->r_addend += r->r_offset; |
| break; |
| } |
| return 0; |
| } |
| |
| #ifndef R_ARM_CALL |
| #define R_ARM_CALL 28 |
| #endif |
| #ifndef R_ARM_JUMP24 |
| #define R_ARM_JUMP24 29 |
| #endif |
| |
| #ifndef R_ARM_THM_CALL |
| #define R_ARM_THM_CALL 10 |
| #endif |
| #ifndef R_ARM_THM_JUMP24 |
| #define R_ARM_THM_JUMP24 30 |
| #endif |
| #ifndef R_ARM_THM_JUMP19 |
| #define R_ARM_THM_JUMP19 51 |
| #endif |
| |
| static int addend_arm_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r) |
| { |
| unsigned int r_typ = ELF_R_TYPE(r->r_info); |
| |
| switch (r_typ) { |
| case R_ARM_ABS32: |
| /* From ARM ABI: (S + A) | T */ |
| r->r_addend = (int)(long) |
| (elf->symtab_start + ELF_R_SYM(r->r_info)); |
| break; |
| case R_ARM_PC24: |
| case R_ARM_CALL: |
| case R_ARM_JUMP24: |
| case R_ARM_THM_CALL: |
| case R_ARM_THM_JUMP24: |
| case R_ARM_THM_JUMP19: |
| /* From ARM ABI: ((S + A) | T) - P */ |
| r->r_addend = (int)(long)(elf->hdr + |
| sechdr->sh_offset + |
| (r->r_offset - sechdr->sh_addr)); |
| break; |
| default: |
| return 1; |
| } |
| return 0; |
| } |
| |
| static int addend_mips_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r) |
| { |
| unsigned int r_typ = ELF_R_TYPE(r->r_info); |
| unsigned int *location = reloc_location(elf, sechdr, r); |
| unsigned int inst; |
| |
| if (r_typ == R_MIPS_HI16) |
| return 1; /* skip this */ |
| inst = TO_NATIVE(*location); |
| switch (r_typ) { |
| case R_MIPS_LO16: |
| r->r_addend = inst & 0xffff; |
| break; |
| case R_MIPS_26: |
| r->r_addend = (inst & 0x03ffffff) << 2; |
| break; |
| case R_MIPS_32: |
| r->r_addend = inst; |
| break; |
| } |
| return 0; |
| } |
| |
| #ifndef EM_RISCV |
| #define EM_RISCV 243 |
| #endif |
| |
| #ifndef R_RISCV_SUB32 |
| #define R_RISCV_SUB32 39 |
| #endif |
| |
| static void section_rela(const char *modname, struct elf_info *elf, |
| Elf_Shdr *sechdr) |
| { |
| Elf_Sym *sym; |
| Elf_Rela *rela; |
| Elf_Rela r; |
| unsigned int r_sym; |
| const char *fromsec; |
| |
| Elf_Rela *start = (void *)elf->hdr + sechdr->sh_offset; |
| Elf_Rela *stop = (void *)start + sechdr->sh_size; |
| |
| fromsec = sech_name(elf, sechdr); |
| fromsec += strlen(".rela"); |
| /* if from section (name) is know good then skip it */ |
| if (match(fromsec, section_white_list)) |
| return; |
| |
| for (rela = start; rela < stop; rela++) { |
| r.r_offset = TO_NATIVE(rela->r_offset); |
| #if KERNEL_ELFCLASS == ELFCLASS64 |
| if (elf->hdr->e_machine == EM_MIPS) { |
| unsigned int r_typ; |
| r_sym = ELF64_MIPS_R_SYM(rela->r_info); |
| r_sym = TO_NATIVE(r_sym); |
| r_typ = ELF64_MIPS_R_TYPE(rela->r_info); |
| r.r_info = ELF64_R_INFO(r_sym, r_typ); |
| } else { |
| r.r_info = TO_NATIVE(rela->r_info); |
| r_sym = ELF_R_SYM(r.r_info); |
| } |
| #else |
| r.r_info = TO_NATIVE(rela->r_info); |
| r_sym = ELF_R_SYM(r.r_info); |
| #endif |
| r.r_addend = TO_NATIVE(rela->r_addend); |
| switch (elf->hdr->e_machine) { |
| case EM_RISCV: |
| if (!strcmp("__ex_table", fromsec) && |
| ELF_R_TYPE(r.r_info) == R_RISCV_SUB32) |
| continue; |
| break; |
| } |
| sym = elf->symtab_start + r_sym; |
| /* Skip special sections */ |
| if (is_shndx_special(sym->st_shndx)) |
| continue; |
| if (is_second_extable_reloc(start, rela, fromsec)) |
| find_extable_entry_size(fromsec, &r); |
| check_section_mismatch(modname, elf, &r, sym, fromsec); |
| } |
| } |
| |
| static void section_rel(const char *modname, struct elf_info *elf, |
| Elf_Shdr *sechdr) |
| { |
| Elf_Sym *sym; |
| Elf_Rel *rel; |
| Elf_Rela r; |
| unsigned int r_sym; |
| const char *fromsec; |
| |
| Elf_Rel *start = (void *)elf->hdr + sechdr->sh_offset; |
| Elf_Rel *stop = (void *)start + sechdr->sh_size; |
| |
| fromsec = sech_name(elf, sechdr); |
| fromsec += strlen(".rel"); |
| /* if from section (name) is know good then skip it */ |
| if (match(fromsec, section_white_list)) |
| return; |
| |
| for (rel = start; rel < stop; rel++) { |
| r.r_offset = TO_NATIVE(rel->r_offset); |
| #if KERNEL_ELFCLASS == ELFCLASS64 |
| if (elf->hdr->e_machine == EM_MIPS) { |
| unsigned int r_typ; |
| r_sym = ELF64_MIPS_R_SYM(rel->r_info); |
| r_sym = TO_NATIVE(r_sym); |
| r_typ = ELF64_MIPS_R_TYPE(rel->r_info); |
| r.r_info = ELF64_R_INFO(r_sym, r_typ); |
| } else { |
| r.r_info = TO_NATIVE(rel->r_info); |
| r_sym = ELF_R_SYM(r.r_info); |
| } |
| #else |
| r.r_info = TO_NATIVE(rel->r_info); |
| r_sym = ELF_R_SYM(r.r_info); |
| #endif |
| r.r_addend = 0; |
| switch (elf->hdr->e_machine) { |
| case EM_386: |
| if (addend_386_rel(elf, sechdr, &r)) |
| continue; |
| break; |
| case EM_ARM: |
| if (addend_arm_rel(elf, sechdr, &r)) |
| continue; |
| break; |
| case EM_MIPS: |
| if (addend_mips_rel(elf, sechdr, &r)) |
| continue; |
| break; |
| } |
| sym = elf->symtab_start + r_sym; |
| /* Skip special sections */ |
| if (is_shndx_special(sym->st_shndx)) |
| continue; |
| if (is_second_extable_reloc(start, rel, fromsec)) |
| find_extable_entry_size(fromsec, &r); |
| check_section_mismatch(modname, elf, &r, sym, fromsec); |
| } |
| } |
| |
| /** |
| * A module includes a number of sections that are discarded |
| * either when loaded or when used as built-in. |
| * For loaded modules all functions marked __init and all data |
| * marked __initdata will be discarded when the module has been initialized. |
| * Likewise for modules used built-in the sections marked __exit |
| * are discarded because __exit marked function are supposed to be called |
| * only when a module is unloaded which never happens for built-in modules. |
| * The check_sec_ref() function traverses all relocation records |
| * to find all references to a section that reference a section that will |
| * be discarded and warns about it. |
| **/ |
| static void check_sec_ref(const char *modname, struct elf_info *elf) |
| { |
| int i; |
| Elf_Shdr *sechdrs = elf->sechdrs; |
| |
| /* Walk through all sections */ |
| for (i = 0; i < elf->num_sections; i++) { |
| check_section(modname, elf, &elf->sechdrs[i]); |
| /* We want to process only relocation sections and not .init */ |
| if (sechdrs[i].sh_type == SHT_RELA) |
| section_rela(modname, elf, &elf->sechdrs[i]); |
| else if (sechdrs[i].sh_type == SHT_REL) |
| section_rel(modname, elf, &elf->sechdrs[i]); |
| } |
| } |
| |
| static char *remove_dot(char *s) |
| { |
| size_t n = strcspn(s, "."); |
| |
| if (n && s[n]) { |
| size_t m = strspn(s + n + 1, "0123456789"); |
| if (m && (s[n + m + 1] == '.' || s[n + m + 1] == 0)) |
| s[n] = 0; |
| } |
| return s; |
| } |
| |
| /* |
| * The CRCs are recorded in .*.cmd files in the form of: |
| * #SYMVER <name> <crc> |
| */ |
| static void extract_crcs_for_object(const char *object, struct module *mod) |
| { |
| char cmd_file[PATH_MAX]; |
| char *buf, *p; |
| const char *base; |
| int dirlen, ret; |
| |
| base = strrchr(object, '/'); |
| if (base) { |
| base++; |
| dirlen = base - object; |
| } else { |
| dirlen = 0; |
| base = object; |
| } |
| |
| ret = snprintf(cmd_file, sizeof(cmd_file), "%.*s.%s.cmd", |
| dirlen, object, base); |
| if (ret >= sizeof(cmd_file)) { |
| error("%s: too long path was truncated\n", cmd_file); |
| return; |
| } |
| |
| buf = read_text_file(cmd_file); |
| p = buf; |
| |
| while ((p = strstr(p, "\n#SYMVER "))) { |
| char *name; |
| size_t namelen; |
| unsigned int crc; |
| struct symbol *sym; |
| |
| name = p + strlen("\n#SYMVER "); |
| |
| p = strchr(name, ' '); |
| if (!p) |
| break; |
| |
| namelen = p - name; |
| p++; |
| |
| if (!isdigit(*p)) |
| continue; /* skip this line */ |
| |
| crc = strtol(p, &p, 0); |
| if (*p != '\n') |
| continue; /* skip this line */ |
| |
| name[namelen] = '\0'; |
| |
| /* |
| * sym_find_with_module() may return NULL here. |
| * It typically occurs when CONFIG_TRIM_UNUSED_KSYMS=y. |
| * Since commit e1327a127703, genksyms calculates CRCs of all |
| * symbols, including trimmed ones. Ignore orphan CRCs. |
| */ |
| sym = sym_find_with_module(name, mod); |
| if (sym) |
| sym_set_crc(sym, crc); |
| } |
| |
| free(buf); |
| } |
| |
| /* |
| * The symbol versions (CRC) are recorded in the .*.cmd files. |
| * Parse them to retrieve CRCs for the current module. |
| */ |
| static void mod_set_crcs(struct module *mod) |
| { |
| char objlist[PATH_MAX]; |
| char *buf, *p, *obj; |
| int ret; |
| |
| if (mod->is_vmlinux) { |
| strcpy(objlist, ".vmlinux.objs"); |
| } else { |
| /* objects for a module are listed in the *.mod file. */ |
| ret = snprintf(objlist, sizeof(objlist), "%s.mod", mod->name); |
| if (ret >= sizeof(objlist)) { |
| error("%s: too long path was truncated\n", objlist); |
| return; |
| } |
| } |
| |
| buf = read_text_file(objlist); |
| p = buf; |
| |
| while ((obj = strsep(&p, "\n")) && obj[0]) |
| extract_crcs_for_object(obj, mod); |
| |
| free(buf); |
| } |
| |
| static void read_symbols(const char *modname) |
| { |
| const char *symname; |
| char *version; |
| char *license; |
| char *namespace; |
| struct module *mod; |
| struct elf_info info = { }; |
| Elf_Sym *sym; |
| |
| if (!parse_elf(&info, modname)) |
| return; |
| |
| if (!strends(modname, ".o")) { |
| error("%s: filename must be suffixed with .o\n", modname); |
| return; |
| } |
| |
| /* strip trailing .o */ |
| mod = new_module(modname, strlen(modname) - strlen(".o")); |
| |
| if (!mod->is_vmlinux) { |
| license = get_modinfo(&info, "license"); |
| if (!license) |
| error("missing MODULE_LICENSE() in %s\n", modname); |
| while (license) { |
| if (!license_is_gpl_compatible(license)) { |
| mod->is_gpl_compatible = false; |
| break; |
| } |
| license = get_next_modinfo(&info, "license", license); |
| } |
| |
| namespace = get_modinfo(&info, "import_ns"); |
| while (namespace) { |
| add_namespace(&mod->imported_namespaces, namespace); |
| namespace = get_next_modinfo(&info, "import_ns", |
| namespace); |
| } |
| } |
| |
| for (sym = info.symtab_start; sym < info.symtab_stop; sym++) { |
| symname = remove_dot(info.strtab + sym->st_name); |
| |
| handle_symbol(mod, &info, sym, symname); |
| handle_moddevtable(mod, &info, sym, symname); |
| } |
| |
| for (sym = info.symtab_start; sym < info.symtab_stop; sym++) { |
| symname = remove_dot(info.strtab + sym->st_name); |
| |
| /* Apply symbol namespaces from __kstrtabns_<symbol> entries. */ |
| if (strstarts(symname, "__kstrtabns_")) |
| sym_update_namespace(symname + strlen("__kstrtabns_"), |
| sym_get_data(&info, sym)); |
| } |
| |
| check_sec_ref(modname, &info); |
| |
| if (!mod->is_vmlinux) { |
| version = get_modinfo(&info, "version"); |
| if (version || all_versions) |
| get_src_version(mod->name, mod->srcversion, |
| sizeof(mod->srcversion) - 1); |
| } |
| |
| parse_elf_finish(&info); |
| |
| if (modversions) { |
| /* |
| * Our trick to get versioning for module struct etc. - it's |
| * never passed as an argument to an exported function, so |
| * the automatic versioning doesn't pick it up, but it's really |
| * important anyhow. |
| */ |
| sym_add_unresolved("module_layout", mod, false); |
| |
| mod_set_crcs(mod); |
| } |
| } |
| |
| static void read_symbols_from_files(const char *filename) |
| { |
| FILE *in = stdin; |
| char fname[PATH_MAX]; |
| |
| if (strcmp(filename, "-") != 0) { |
| in = fopen(filename, "r"); |
| if (!in) |
| fatal("Can't open filenames file %s: %m", filename); |
| } |
| |
| while (fgets(fname, PATH_MAX, in) != NULL) { |
| if (strends(fname, "\n")) |
| fname[strlen(fname)-1] = '\0'; |
| read_symbols(fname); |
| } |
| |
| if (in != stdin) |
| fclose(in); |
| } |
| |
| #define SZ 500 |
| |
| /* We first write the generated file into memory using the |
| * following helper, then compare to the file on disk and |
| * only update the later if anything changed */ |
| |
| void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf, |
| const char *fmt, ...) |
| { |
| char tmp[SZ]; |
| int len; |
| va_list ap; |
| |
| va_start(ap, fmt); |
| len = vsnprintf(tmp, SZ, fmt, ap); |
| buf_write(buf, tmp, len); |
| va_end(ap); |
| } |
| |
| void buf_write(struct buffer *buf, const char *s, int len) |
| { |
| if (buf->size - buf->pos < len) { |
| buf->size += len + SZ; |
| buf->p = NOFAIL(realloc(buf->p, buf->size)); |
| } |
| strncpy(buf->p + buf->pos, s, len); |
| buf->pos += len; |
| } |
| |
| static void check_exports(struct module *mod) |
| { |
| struct symbol *s, *exp; |
| |
| list_for_each_entry(s, &mod->unresolved_symbols, list) { |
| const char *basename; |
| exp = find_symbol(s->name); |
| if (!exp) { |
| if (!s->weak && nr_unresolved++ < MAX_UNRESOLVED_REPORTS) |
| modpost_log(warn_unresolved ? LOG_WARN : LOG_ERROR, |
| "\"%s\" [%s.ko] undefined!\n", |
| s->name, mod->name); |
| continue; |
| } |
| if (exp->module == mod) { |
| error("\"%s\" [%s.ko] was exported without definition\n", |
| s->name, mod->name); |
| continue; |
| } |
| |
| s->module = exp->module; |
| s->crc_valid = exp->crc_valid; |
| s->crc = exp->crc; |
| |
| basename = strrchr(mod->name, '/'); |
| if (basename) |
| basename++; |
| else |
| basename = mod->name; |
| |
| if (exp->namespace && |
| !contains_namespace(&mod->imported_namespaces, exp->namespace)) { |
| modpost_log(allow_missing_ns_imports ? LOG_WARN : LOG_ERROR, |
| "module %s uses symbol %s from namespace %s, but does not import it.\n", |
| basename, exp->name, exp->namespace); |
| add_namespace(&mod->missing_namespaces, exp->namespace); |
| } |
| |
| if (!mod->is_gpl_compatible && exp->is_gpl_only) |
| error("GPL-incompatible module %s.ko uses GPL-only symbol '%s'\n", |
| basename, exp->name); |
| } |
| } |
| |
| static void check_modname_len(struct module *mod) |
| { |
| const char *mod_name; |
| |
| mod_name = strrchr(mod->name, '/'); |
| if (mod_name == NULL) |
| mod_name = mod->name; |
| else |
| mod_name++; |
| if (strlen(mod_name) >= MODULE_NAME_LEN) |
| error("module name is too long [%s.ko]\n", mod->name); |
| } |
| |
| /** |
| * Header for the generated file |
| **/ |
| static void add_header(struct buffer *b, struct module *mod) |
| { |
| buf_printf(b, "#include <linux/module.h>\n"); |
| /* |
| * Include build-salt.h after module.h in order to |
| * inherit the definitions. |
| */ |
| buf_printf(b, "#define INCLUDE_VERMAGIC\n"); |
| buf_printf(b, "#include <linux/build-salt.h>\n"); |
| buf_printf(b, "#include <linux/elfnote-lto.h>\n"); |
| buf_printf(b, "#include <linux/export-internal.h>\n"); |
| buf_printf(b, "#include <linux/vermagic.h>\n"); |
| buf_printf(b, "#include <linux/compiler.h>\n"); |
| buf_printf(b, "\n"); |
| buf_printf(b, "BUILD_SALT;\n"); |
| buf_printf(b, "BUILD_LTO_INFO;\n"); |
| buf_printf(b, "\n"); |
| buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n"); |
| buf_printf(b, "MODULE_INFO(name, KBUILD_MODNAME);\n"); |
| buf_printf(b, "\n"); |
| buf_printf(b, "__visible struct module __this_module\n"); |
| buf_printf(b, "__section(\".gnu.linkonce.this_module\") = {\n"); |
| buf_printf(b, "\t.name = KBUILD_MODNAME,\n"); |
| if (mod->has_init) |
| buf_printf(b, "\t.init = init_module,\n"); |
| if (mod->has_cleanup) |
| buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n" |
| "\t.exit = cleanup_module,\n" |
| "#endif\n"); |
| buf_printf(b, "\t.arch = MODULE_ARCH_INIT,\n"); |
| buf_printf(b, "};\n"); |
| |
| if (!external_module) |
| buf_printf(b, "\nMODULE_INFO(intree, \"Y\");\n"); |
| |
| buf_printf(b, |
| "\n" |
| "#ifdef CONFIG_RETPOLINE\n" |
| "MODULE_INFO(retpoline, \"Y\");\n" |
| "#endif\n"); |
| |
| if (strstarts(mod->name, "drivers/staging")) |
| buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n"); |
| } |
| |
| static void add_exported_symbols(struct buffer *buf, struct module *mod) |
| { |
| struct symbol *sym; |
| |
| if (!modversions) |
| return; |
| |
| /* record CRCs for exported symbols */ |
| buf_printf(buf, "\n"); |
| list_for_each_entry(sym, &mod->exported_symbols, list) { |
| if (!sym->crc_valid) { |
| warn("EXPORT symbol \"%s\" [%s%s] version generation failed, symbol will not be versioned.\n" |
| "Is \"%s\" prototyped in <asm/asm-prototypes.h>?\n", |
| sym->name, mod->name, mod->is_vmlinux ? "" : ".ko", |
| sym->name); |
| continue; |
| } |
| |
| buf_printf(buf, "SYMBOL_CRC(%s, 0x%08x, \"%s\");\n", |
| sym->name, sym->crc, sym->is_gpl_only ? "_gpl" : ""); |
| } |
| } |
| |
| /** |
| * Record CRCs for unresolved symbols |
| **/ |
| static void add_versions(struct buffer *b, struct module *mod) |
| { |
| struct symbol *s; |
| |
| if (!modversions) |
| return; |
| |
| buf_printf(b, "\n"); |
| buf_printf(b, "static const struct modversion_info ____versions[]\n"); |
| buf_printf(b, "__used __section(\"__versions\") = {\n"); |
| |
| list_for_each_entry(s, &mod->unresolved_symbols, list) { |
| if (!s->module) |
| continue; |
| if (!s->crc_valid) { |
| warn("\"%s\" [%s.ko] has no CRC!\n", |
| s->name, mod->name); |
| continue; |
| } |
| if (strlen(s->name) >= MODULE_NAME_LEN) { |
| error("too long symbol \"%s\" [%s.ko]\n", |
| s->name, mod->name); |
| break; |
| } |
| buf_printf(b, "\t{ %#8x, \"%s\" },\n", |
| s->crc, s->name); |
| } |
| |
| buf_printf(b, "};\n"); |
| } |
| |
| static void add_depends(struct buffer *b, struct module *mod) |
| { |
| struct symbol *s; |
| int first = 1; |
| |
| /* Clear ->seen flag of modules that own symbols needed by this. */ |
| list_for_each_entry(s, &mod->unresolved_symbols, list) { |
| if (s->module) |
| s->module->seen = s->module->is_vmlinux; |
| } |
| |
| buf_printf(b, "\n"); |
| buf_printf(b, "MODULE_INFO(depends, \""); |
| list_for_each_entry(s, &mod->unresolved_symbols, list) { |
| const char *p; |
| if (!s->module) |
| continue; |
| |
| if (s->module->seen) |
| continue; |
| |
| s->module->seen = true; |
| p = strrchr(s->module->name, '/'); |
| if (p) |
| p++; |
| else |
| p = s->module->name; |
| buf_printf(b, "%s%s", first ? "" : ",", p); |
| first = 0; |
| } |
| buf_printf(b, "\");\n"); |
| } |
| |
| static void add_srcversion(struct buffer *b, struct module *mod) |
| { |
| if (mod->srcversion[0]) { |
| buf_printf(b, "\n"); |
| buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n", |
| mod->srcversion); |
| } |
| } |
| |
| static void write_buf(struct buffer *b, const char *fname) |
| { |
| FILE *file; |
| |
| if (error_occurred) |
| return; |
| |
| file = fopen(fname, "w"); |
| if (!file) { |
| perror(fname); |
| exit(1); |
| } |
| if (fwrite(b->p, 1, b->pos, file) != b->pos) { |
| perror(fname); |
| exit(1); |
| } |
| if (fclose(file) != 0) { |
| perror(fname); |
| exit(1); |
| } |
| } |
| |
| static void write_if_changed(struct buffer *b, const char *fname) |
| { |
| char *tmp; |
| FILE *file; |
| struct stat st; |
| |
| file = fopen(fname, "r"); |
| if (!file) |
| goto write; |
| |
| if (fstat(fileno(file), &st) < 0) |
| goto close_write; |
| |
| if (st.st_size != b->pos) |
| goto close_write; |
| |
| tmp = NOFAIL(malloc(b->pos)); |
| if (fread(tmp, 1, b->pos, file) != b->pos) |
| goto free_write; |
| |
| if (memcmp(tmp, b->p, b->pos) != 0) |
| goto free_write; |
| |
| free(tmp); |
| fclose(file); |
| return; |
| |
| free_write: |
| free(tmp); |
| close_write: |
| fclose(file); |
| write: |
| write_buf(b, fname); |
| } |
| |
| static void write_vmlinux_export_c_file(struct module *mod) |
| { |
| struct buffer buf = { }; |
| |
| buf_printf(&buf, |
| "#include <linux/export-internal.h>\n"); |
| |
| add_exported_symbols(&buf, mod); |
| write_if_changed(&buf, ".vmlinux.export.c"); |
| free(buf.p); |
| } |
| |
| /* do sanity checks, and generate *.mod.c file */ |
| static void write_mod_c_file(struct module *mod) |
| { |
| struct buffer buf = { }; |
| char fname[PATH_MAX]; |
| int ret; |
| |
| check_modname_len(mod); |
| check_exports(mod); |
| |
| add_header(&buf, mod); |
| add_exported_symbols(&buf, mod); |
| add_versions(&buf, mod); |
| add_depends(&buf, mod); |
| add_moddevtable(&buf, mod); |
| add_srcversion(&buf, mod); |
| |
| ret = snprintf(fname, sizeof(fname), "%s.mod.c", mod->name); |
| if (ret >= sizeof(fname)) { |
| error("%s: too long path was truncated\n", fname); |
| goto free; |
| } |
| |
| write_if_changed(&buf, fname); |
| |
| free: |
| free(buf.p); |
| } |
| |
| /* parse Module.symvers file. line format: |
| * 0x12345678<tab>symbol<tab>module<tab>export<tab>namespace |
| **/ |
| static void read_dump(const char *fname) |
| { |
| char *buf, *pos, *line; |
| |
| buf = read_text_file(fname); |
| if (!buf) |
| /* No symbol versions, silently ignore */ |
| return; |
| |
| pos = buf; |
| |
| while ((line = get_line(&pos))) { |
| char *symname, *namespace, *modname, *d, *export; |
| unsigned int crc; |
| struct module *mod; |
| struct symbol *s; |
| bool gpl_only; |
| |
| if (!(symname = strchr(line, '\t'))) |
| goto fail; |
| *symname++ = '\0'; |
| if (!(modname = strchr(symname, '\t'))) |
| goto fail; |
| *modname++ = '\0'; |
| if (!(export = strchr(modname, '\t'))) |
| goto fail; |
| *export++ = '\0'; |
| if (!(namespace = strchr(export, '\t'))) |
| goto fail; |
| *namespace++ = '\0'; |
| |
| crc = strtoul(line, &d, 16); |
| if (*symname == '\0' || *modname == '\0' || *d != '\0') |
| goto fail; |
| |
| if (!strcmp(export, "EXPORT_SYMBOL_GPL")) { |
| gpl_only = true; |
| } else if (!strcmp(export, "EXPORT_SYMBOL")) { |
| gpl_only = false; |
| } else { |
| error("%s: unknown license %s. skip", symname, export); |
| continue; |
| } |
| |
| mod = find_module(modname); |
| if (!mod) { |
| mod = new_module(modname, strlen(modname)); |
| mod->from_dump = true; |
| } |
| s = sym_add_exported(symname, mod, gpl_only); |
| sym_set_crc(s, crc); |
| sym_update_namespace(symname, namespace); |
| } |
| free(buf); |
| return; |
| fail: |
| free(buf); |
| fatal("parse error in symbol dump file\n"); |
| } |
| |
| static void write_dump(const char *fname) |
| { |
| struct buffer buf = { }; |
| struct module *mod; |
| struct symbol *sym; |
| |
| list_for_each_entry(mod, &modules, list) { |
| if (mod->from_dump) |
| continue; |
| list_for_each_entry(sym, &mod->exported_symbols, list) { |
| buf_printf(&buf, "0x%08x\t%s\t%s\tEXPORT_SYMBOL%s\t%s\n", |
| sym->crc, sym->name, mod->name, |
| sym->is_gpl_only ? "_GPL" : "", |
| sym->namespace ?: ""); |
| } |
| } |
| write_buf(&buf, fname); |
| free(buf.p); |
| } |
| |
| static void write_namespace_deps_files(const char *fname) |
| { |
| struct module *mod; |
| struct namespace_list *ns; |
| struct buffer ns_deps_buf = {}; |
| |
| list_for_each_entry(mod, &modules, list) { |
| |
| if (mod->from_dump || list_empty(&mod->missing_namespaces)) |
| continue; |
| |
| buf_printf(&ns_deps_buf, "%s.ko:", mod->name); |
| |
| list_for_each_entry(ns, &mod->missing_namespaces, list) |
| buf_printf(&ns_deps_buf, " %s", ns->namespace); |
| |
| buf_printf(&ns_deps_buf, "\n"); |
| } |
| |
| write_if_changed(&ns_deps_buf, fname); |
| free(ns_deps_buf.p); |
| } |
| |
| struct dump_list { |
| struct list_head list; |
| const char *file; |
| }; |
| |
| int main(int argc, char **argv) |
| { |
| struct module *mod; |
| char *missing_namespace_deps = NULL; |
| char *dump_write = NULL, *files_source = NULL; |
| int opt; |
| LIST_HEAD(dump_lists); |
| struct dump_list *dl, *dl2; |
| |
| while ((opt = getopt(argc, argv, "ei:mnT:o:awENd:")) != -1) { |
| switch (opt) { |
| case 'e': |
| external_module = true; |
| break; |
| case 'i': |
| dl = NOFAIL(malloc(sizeof(*dl))); |
| dl->file = optarg; |
| list_add_tail(&dl->list, &dump_lists); |
| break; |
| case 'm': |
| modversions = true; |
| break; |
| case 'n': |
| ignore_missing_files = true; |
| break; |
| case 'o': |
| dump_write = optarg; |
| break; |
| case 'a': |
| all_versions = true; |
| break; |
| case 'T': |
| files_source = optarg; |
| break; |
| case 'w': |
| warn_unresolved = true; |
| break; |
| case 'E': |
| sec_mismatch_warn_only = false; |
| break; |
| case 'N': |
| allow_missing_ns_imports = true; |
| break; |
| case 'd': |
| missing_namespace_deps = optarg; |
| break; |
| default: |
| exit(1); |
| } |
| } |
| |
| list_for_each_entry_safe(dl, dl2, &dump_lists, list) { |
| read_dump(dl->file); |
| list_del(&dl->list); |
| free(dl); |
| } |
| |
| while (optind < argc) |
| read_symbols(argv[optind++]); |
| |
| if (files_source) |
| read_symbols_from_files(files_source); |
| |
| list_for_each_entry(mod, &modules, list) { |
| if (mod->from_dump) |
| continue; |
| |
| if (mod->is_vmlinux) |
| write_vmlinux_export_c_file(mod); |
| else |
| write_mod_c_file(mod); |
| } |
| |
| if (missing_namespace_deps) |
| write_namespace_deps_files(missing_namespace_deps); |
| |
| if (dump_write) |
| write_dump(dump_write); |
| if (sec_mismatch_count && !sec_mismatch_warn_only) |
| error("Section mismatches detected.\n" |
| "Set CONFIG_SECTION_MISMATCH_WARN_ONLY=y to allow them.\n"); |
| |
| if (nr_unresolved > MAX_UNRESOLVED_REPORTS) |
| warn("suppressed %u unresolved symbol warnings because there were too many)\n", |
| nr_unresolved - MAX_UNRESOLVED_REPORTS); |
| |
| return error_occurred ? 1 : 0; |
| } |