diff options
Diffstat (limited to '')
| -rw-r--r-- | scripts/mod/modpost.c | 2681 |
1 files changed, 2681 insertions, 0 deletions
diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c new file mode 100644 index 000000000..78ac98cfa --- /dev/null +++ b/scripts/mod/modpost.c @@ -0,0 +1,2681 @@ +/* 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 <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 int modversions = 0; +/* Warn about undefined symbols? (do so if we have vmlinux) */ +static int have_vmlinux = 0; +/* Is CONFIG_MODULE_SRCVERSION_ALL set? */ +static int all_versions = 0; +/* If we are modposting external module set to 1 */ +static int external_module = 0; +/* Only warn about unresolved symbols */ +static int warn_unresolved = 0; +/* How a symbol is exported */ +static int sec_mismatch_count = 0; +static int sec_mismatch_fatal = 0; +/* ignore missing files */ +static int ignore_missing_files; +/* If set to 1, only warn (instead of error) about missing ns imports */ +static int allow_missing_ns_imports; + +enum export { + export_plain, export_unused, export_gpl, + export_unused_gpl, export_gpl_future, export_unknown +}; + +/* 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); +} + +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 */ +static struct module *modules; + +static struct module *find_module(const char *modname) +{ + struct module *mod; + + for (mod = modules; mod; mod = mod->next) + if (strcmp(mod->name, modname) == 0) + break; + return mod; +} + +static struct module *new_module(const char *modname) +{ + struct module *mod; + + mod = NOFAIL(malloc(sizeof(*mod) + strlen(modname) + 1)); + memset(mod, 0, sizeof(*mod)); + + /* add to list */ + strcpy(mod->name, modname); + mod->is_vmlinux = (strcmp(modname, "vmlinux") == 0); + mod->gpl_compatible = -1; + mod->next = modules; + modules = mod; + + if (mod->is_vmlinux) + have_vmlinux = 1; + + 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 module *module; + unsigned int crc; + int crc_valid; + char *namespace; + unsigned int weak:1; + unsigned int is_static:1; /* 1 if symbol is not global */ + enum export export; /* Type of export */ + char name[]; +}; + +static struct symbol *symbolhash[SYMBOL_HASH_SIZE]; + +/* This is based on the hash agorithm 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, unsigned int weak, + struct symbol *next) +{ + struct symbol *s = NOFAIL(malloc(sizeof(*s) + strlen(name) + 1)); + + memset(s, 0, sizeof(*s)); + strcpy(s->name, name); + s->weak = weak; + s->next = next; + s->is_static = 1; + return s; +} + +/* For the hash of exported symbols */ +static struct symbol *new_symbol(const char *name, struct module *module, + enum export export) +{ + unsigned int hash; + + hash = tdb_hash(name) % SYMBOL_HASH_SIZE; + symbolhash[hash] = alloc_symbol(name, 0, symbolhash[hash]); + + return symbolhash[hash]; +} + +static struct symbol *find_symbol(const char *name) +{ + 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) + return s; + } + return NULL; +} + +static bool contains_namespace(struct namespace_list *list, + const char *namespace) +{ + for (; list; list = list->next) + if (!strcmp(list->namespace, namespace)) + return true; + + return false; +} + +static void add_namespace(struct namespace_list **list, const char *namespace) +{ + struct namespace_list *ns_entry; + + if (!contains_namespace(*list, namespace)) { + ns_entry = NOFAIL(malloc(sizeof(struct namespace_list) + + strlen(namespace) + 1)); + strcpy(ns_entry->namespace, namespace); + ns_entry->next = *list; + *list = ns_entry; + } +} + +static bool module_imports_namespace(struct module *module, + const char *namespace) +{ + return contains_namespace(module->imported_namespaces, namespace); +} + +static const struct { + const char *str; + enum export export; +} export_list[] = { + { .str = "EXPORT_SYMBOL", .export = export_plain }, + { .str = "EXPORT_UNUSED_SYMBOL", .export = export_unused }, + { .str = "EXPORT_SYMBOL_GPL", .export = export_gpl }, + { .str = "EXPORT_UNUSED_SYMBOL_GPL", .export = export_unused_gpl }, + { .str = "EXPORT_SYMBOL_GPL_FUTURE", .export = export_gpl_future }, + { .str = "(unknown)", .export = export_unknown }, +}; + + +static const char *export_str(enum export ex) +{ + return export_list[ex].str; +} + +static enum export export_no(const char *s) +{ + int i; + + if (!s) + return export_unknown; + for (i = 0; export_list[i].export != export_unknown; i++) { + if (strcmp(export_list[i].str, s) == 0) + return export_list[i].export; + } + return export_unknown; +} + +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 enum export export_from_secname(struct elf_info *elf, unsigned int sec) +{ + const char *secname = sec_name(elf, sec); + + if (strstarts(secname, "___ksymtab+")) + return export_plain; + else if (strstarts(secname, "___ksymtab_unused+")) + return export_unused; + else if (strstarts(secname, "___ksymtab_gpl+")) + return export_gpl; + else if (strstarts(secname, "___ksymtab_unused_gpl+")) + return export_unused_gpl; + else if (strstarts(secname, "___ksymtab_gpl_future+")) + return export_gpl_future; + else + return export_unknown; +} + +static enum export export_from_sec(struct elf_info *elf, unsigned int sec) +{ + if (sec == elf->export_sec) + return export_plain; + else if (sec == elf->export_unused_sec) + return export_unused; + else if (sec == elf->export_gpl_sec) + return export_gpl; + else if (sec == elf->export_unused_gpl_sec) + return export_unused_gpl; + else if (sec == elf->export_gpl_future_sec) + return export_gpl_future; + else + return export_unknown; +} + +static const char *namespace_from_kstrtabns(const struct elf_info *info, + const Elf_Sym *sym) +{ + const char *value = sym_get_data(info, sym); + return value[0] ? value : NULL; +} + +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) { + merror("Could not update namespace(%s) for symbol %s\n", + namespace, symname); + return; + } + + free(s->namespace); + s->namespace = + namespace && namespace[0] ? NOFAIL(strdup(namespace)) : NULL; +} + +/** + * Add an exported symbol - it may have already been added without a + * CRC, in this case just update the CRC + **/ +static struct symbol *sym_add_exported(const char *name, struct module *mod, + enum export export) +{ + struct symbol *s = find_symbol(name); + + if (!s) { + s = new_symbol(name, mod, export); + } else if (!external_module || s->module->is_vmlinux || + s->module == mod) { + warn("%s: '%s' exported twice. Previous export was in %s%s\n", + mod->name, name, s->module->name, + s->module->is_vmlinux ? "" : ".ko"); + return s; + } + + s->module = mod; + s->export = export; + return s; +} + +static void sym_set_crc(const char *name, unsigned int crc) +{ + struct symbol *s = find_symbol(name); + + /* + * Ignore stand-alone __crc_*, which might be auto-generated symbols + * such as __*_veneer in ARM ELF. + */ + if (!s) + return; + + s->crc = crc; + s->crc_valid = 1; +} + +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; + } else if (strcmp(secname, "__ksymtab") == 0) + info->export_sec = i; + else if (strcmp(secname, "__ksymtab_unused") == 0) + info->export_unused_sec = i; + else if (strcmp(secname, "__ksymtab_gpl") == 0) + info->export_gpl_sec = i; + else if (strcmp(secname, "__ksymtab_unused_gpl") == 0) + info->export_unused_gpl_sec = i; + else if (strcmp(secname, "__ksymtab_gpl_future") == 0) + info->export_gpl_future_sec = i; + + 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; + /* Do not ignore this symbol */ + return 0; +} + +static void handle_modversion(const struct module *mod, + const struct elf_info *info, + const Elf_Sym *sym, const char *symname) +{ + unsigned int crc; + + if (sym->st_shndx == SHN_UNDEF) { + warn("EXPORT symbol \"%s\" [%s%s] version generation failed, symbol will not be versioned.\n", + symname, mod->name, mod->is_vmlinux ? "" : ".ko"); + return; + } + + if (sym->st_shndx == SHN_ABS) { + crc = sym->st_value; + } else { + unsigned int *crcp; + + /* symbol points to the CRC in the ELF object */ + crcp = sym_get_data(info, sym); + crc = TO_NATIVE(*crcp); + } + sym_set_crc(symname, crc); +} + +static void handle_symbol(struct module *mod, struct elf_info *info, + const Elf_Sym *sym, const char *symname) +{ + enum export export; + const char *name; + + if (strstarts(symname, "__ksymtab")) + export = export_from_secname(info, get_secindex(info, sym)); + else + export = export_from_sec(info, get_secindex(info, sym)); + + 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; + } + } + + mod->unres = alloc_symbol(symname, + ELF_ST_BIND(sym->st_info) == STB_WEAK, + mod->unres); + break; + default: + /* All exported symbols */ + if (strstarts(symname, "__ksymtab_")) { + name = symname + strlen("__ksymtab_"); + sym_add_exported(name, mod, export); + } + if (strcmp(symname, "init_module") == 0) + mod->has_init = 1; + if (strcmp(symname, "cleanup_module") == 0) + mod->has_cleanup = 1; + 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); +} + +/** + * Test if string s ends in string sub + * return 0 if match + **/ +static int strrcmp(const char *s, const char *sub) +{ + int slen, sublen; + + if (!s || !sub) + return 1; + + slen = strlen(s); + sublen = strlen(sub); + + if ((slen == 0) || (sublen == 0)) + return 1; + + if (sublen > slen) + return 1; + + return memcmp(s + slen - sublen, sub, sublen); +} + +static const char *sym_name(struct elf_info *elf, Elf_Sym *sym) +{ + if (sym) + return elf->strtab + sym->st_name; + else + return "(unknown)"; +} + +/* The pattern is an array of simple patterns. + * "foo" will match an exact string equal to "foo" + * "*foo" will match a string that ends with "foo" + * "foo*" will match a string that begins with "foo" + * "*foo*" will match a string that contains "foo" + */ +static int match(const char *sym, const char * const pat[]) +{ + const char *p; + while (*pat) { + p = *pat++; + const char *endp = p + strlen(p) - 1; + + /* "*foo*" */ + if (*p == '*' && *endp == '*') { + char *bare = NOFAIL(strndup(p + 1, strlen(p) - 2)); + char *here = strstr(sym, bare); + + free(bare); + if (here != NULL) + return 1; + } + /* "*foo" */ + else if (*p == '*') { + if (strrcmp(sym, p + 1) == 0) + return 1; + } + /* "foo*" */ + else if (*endp == '*') { + if (strncmp(sym, p, strlen(p) - 1) == 0) + return 1; + } + /* no wildcards */ + else { + if (strcmp(p, sym) == 0) + return 1; + } + } + /* no match */ + return 0; +} + +/* 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" + +#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 criterias: + * + * @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 + * targetting 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 targetting 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; + int elems = sizeof(sectioncheck) / sizeof(struct sectioncheck); + const struct sectioncheck *check = §ioncheck[0]; + + /* + * 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 < elems; 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; + } + 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; + + /* + * Strive to find a better symbol name, but the resulting name may not + * match the symbol referenced in the original code. + */ + 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) { + if ((addr - sym->st_value) < distance) { + distance = addr - sym->st_value; + near = sym; + } else if ((addr - sym->st_value) == distance) { + 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 int32_t sign_extend32(int32_t value, int index) +{ + uint8_t shift = 31 - index; + + return (int32_t)(value << shift) >> shift; +} + +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); + Elf_Sym *sym = elf->symtab_start + ELF_R_SYM(r->r_info); + void *loc = reloc_location(elf, sechdr, r); + uint32_t inst; + int32_t offset; + + switch (r_typ) { + case R_ARM_ABS32: + inst = TO_NATIVE(*(uint32_t *)loc); + r->r_addend = inst + sym->st_value; + break; + case R_ARM_PC24: + case R_ARM_CALL: + case R_ARM_JUMP24: + inst = TO_NATIVE(*(uint32_t *)loc); + offset = sign_extend32((inst & 0x00ffffff) << 2, 25); + r->r_addend = offset + sym->st_value + 8; + break; + 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; +} + +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); + 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(struct module *mod, 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; +} + +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; + + { + char *tmp; + + /* strip trailing .o */ + tmp = NOFAIL(strdup(modname)); + tmp[strlen(tmp) - 2] = '\0'; + mod = new_module(tmp); + free(tmp); + } + + if (!mod->is_vmlinux) { + license = get_modinfo(&info, "license"); + if (!license) + warn("missing MODULE_LICENSE() in %s\n", modname); + while (license) { + if (license_is_gpl_compatible(license)) + mod->gpl_compatible = 1; + else { + mod->gpl_compatible = 0; + 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_"), + namespace_from_kstrtabns(&info, + sym)); + + if (strstarts(symname, "__crc_")) + handle_modversion(mod, &info, sym, + symname + strlen("__crc_")); + } + + // check for static EXPORT_SYMBOL_* functions && global vars + for (sym = info.symtab_start; sym < info.symtab_stop; sym++) { + unsigned char bind = ELF_ST_BIND(sym->st_info); + + if (bind == STB_GLOBAL || bind == STB_WEAK) { + struct symbol *s = + find_symbol(remove_dot(info.strtab + + sym->st_name)); + + if (s) + s->is_static = 0; + } + } + + check_sec_ref(mod, modname, &info); + + if (!mod->is_vmlinux) { + version = get_modinfo(&info, "version"); + if (version || all_versions) + get_src_version(modname, mod->srcversion, + sizeof(mod->srcversion) - 1); + } + + parse_elf_finish(&info); + + /* 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 */ + if (modversions) + mod->unres = alloc_symbol("module_layout", 0, mod->unres); +} + +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_for_gpl_usage(enum export exp, const char *m, const char *s) +{ + switch (exp) { + case export_gpl: + fatal("GPL-incompatible module %s.ko uses GPL-only symbol '%s'\n", + m, s); + break; + case export_unused_gpl: + fatal("GPL-incompatible module %s.ko uses GPL-only symbol marked UNUSED '%s'\n", + m, s); + break; + case export_gpl_future: + warn("GPL-incompatible module %s.ko uses future GPL-only symbol '%s'\n", + m, s); + break; + case export_plain: + case export_unused: + case export_unknown: + /* ignore */ + break; + } +} + +static void check_for_unused(enum export exp, const char *m, const char *s) +{ + switch (exp) { + case export_unused: + case export_unused_gpl: + warn("module %s.ko uses symbol '%s' marked UNUSED\n", + m, s); + break; + default: + /* ignore */ + break; + } +} + +static int check_exports(struct module *mod) +{ + struct symbol *s, *exp; + int err = 0; + + for (s = mod->unres; s; s = s->next) { + const char *basename; + exp = find_symbol(s->name); + if (!exp || exp->module == mod) { + if (have_vmlinux && !s->weak) { + modpost_log(warn_unresolved ? LOG_WARN : LOG_ERROR, + "\"%s\" [%s.ko] undefined!\n", + s->name, mod->name); + if (!warn_unresolved) + err = 1; + } + continue; + } + basename = strrchr(mod->name, '/'); + if (basename) + basename++; + else + basename = mod->name; + + if (exp->namespace && + !module_imports_namespace(mod, 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); + if (!allow_missing_ns_imports) + err = 1; + add_namespace(&mod->missing_namespaces, exp->namespace); + } + + if (!mod->gpl_compatible) + check_for_gpl_usage(exp->export, basename, exp->name); + check_for_unused(exp->export, basename, exp->name); + } + + return err; +} + +static int 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) { + merror("module name is too long [%s.ko]\n", mod->name); + return 1; + } + + return 0; +} + +/** + * 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/vermagic.h>\n"); + buf_printf(b, "#include <linux/compiler.h>\n"); + buf_printf(b, "\n"); + buf_printf(b, "BUILD_SALT;\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"); +} + +static void add_intree_flag(struct buffer *b, int is_intree) +{ + if (is_intree) + buf_printf(b, "\nMODULE_INFO(intree, \"Y\");\n"); +} + +/* Cannot check for assembler */ +static void add_retpoline(struct buffer *b) +{ + buf_printf(b, "\n#ifdef CONFIG_RETPOLINE\n"); + buf_printf(b, "MODULE_INFO(retpoline, \"Y\");\n"); + buf_printf(b, "#endif\n"); +} + +static void add_staging_flag(struct buffer *b, const char *name) +{ + if (strstarts(name, "drivers/staging")) + buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n"); +} + +/** + * Record CRCs for unresolved symbols + **/ +static int add_versions(struct buffer *b, struct module *mod) +{ + struct symbol *s, *exp; + int err = 0; + + for (s = mod->unres; s; s = s->next) { + exp = find_symbol(s->name); + if (!exp || exp->module == mod) + continue; + s->module = exp->module; + s->crc_valid = exp->crc_valid; + s->crc = exp->crc; + } + + if (!modversions) + return err; + + buf_printf(b, "\n"); + buf_printf(b, "static const struct modversion_info ____versions[]\n"); + buf_printf(b, "__used __section(\"__versions\") = {\n"); + + for (s = mod->unres; s; s = s->next) { + 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) { + merror("too long symbol \"%s\" [%s.ko]\n", + s->name, mod->name); + err = 1; + break; + } + buf_printf(b, "\t{ %#8x, \"%s\" },\n", + s->crc, s->name); + } + + buf_printf(b, "};\n"); + + return err; +} + +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. */ + for (s = mod->unres; s; s = s->next) + if (s->module) + s->module->seen = s->module->is_vmlinux; + + buf_printf(b, "\n"); + buf_printf(b, "MODULE_INFO(depends, \""); + for (s = mod->unres; s; s = s->next) { + const char *p; + if (!s->module) + continue; + + if (s->module->seen) + continue; + + s->module->seen = 1; + 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; + + 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); +} + +/* 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; + + 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; + mod = find_module(modname); + if (!mod) { + mod = new_module(modname); + mod->from_dump = 1; + } + s = sym_add_exported(symname, mod, export_no(export)); + s->is_static = 0; + sym_set_crc(symname, 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 symbol *symbol; + const char *namespace; + int n; + + for (n = 0; n < SYMBOL_HASH_SIZE ; n++) { + symbol = symbolhash[n]; + while (symbol) { + if (!symbol->module->from_dump) { + namespace = symbol->namespace; + buf_printf(&buf, "0x%08x\t%s\t%s\t%s\t%s\n", + symbol->crc, symbol->name, + symbol->module->name, + export_str(symbol->export), + namespace ? namespace : ""); + } + symbol = symbol->next; + } + } + 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 = {}; + + for (mod = modules; mod; mod = mod->next) { + + if (mod->from_dump || !mod->missing_namespaces) + continue; + + buf_printf(&ns_deps_buf, "%s.ko:", mod->name); + + for (ns = mod->missing_namespaces; ns; ns = ns->next) + 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 dump_list *next; + const char *file; +}; + +int main(int argc, char **argv) +{ + struct module *mod; + struct buffer buf = { }; + char *missing_namespace_deps = NULL; + char *dump_write = NULL, *files_source = NULL; + int opt; + int err; + int n; + struct dump_list *dump_read_start = NULL; + struct dump_list **dump_read_iter = &dump_read_start; + + while ((opt = getopt(argc, argv, "ei:mnT:o:awENd:")) != -1) { + switch (opt) { + case 'e': + external_module = 1; + break; + case 'i': + *dump_read_iter = + NOFAIL(calloc(1, sizeof(**dump_read_iter))); + (*dump_read_iter)->file = optarg; + dump_read_iter = &(*dump_read_iter)->next; + break; + case 'm': + modversions = 1; + break; + case 'n': + ignore_missing_files = 1; + break; + case 'o': + dump_write = optarg; + break; + case 'a': + all_versions = 1; + break; + case 'T': + files_source = optarg; + break; + case 'w': + warn_unresolved = 1; + break; + case 'E': + sec_mismatch_fatal = 1; + break; + case 'N': + allow_missing_ns_imports = 1; + break; + case 'd': + missing_namespace_deps = optarg; + break; + default: + exit(1); + } + } + + while (dump_read_start) { + struct dump_list *tmp; + + read_dump(dump_read_start->file); + tmp = dump_read_start->next; + free(dump_read_start); + dump_read_start = tmp; + } + + while (optind < argc) + read_symbols(argv[optind++]); + + if (files_source) + read_symbols_from_files(files_source); + + /* + * When there's no vmlinux, don't print warnings about + * unresolved symbols (since there'll be too many ;) + */ + if (!have_vmlinux) + warn("Symbol info of vmlinux is missing. Unresolved symbol check will be entirely skipped.\n"); + + err = 0; + + for (mod = modules; mod; mod = mod->next) { + char fname[PATH_MAX]; + + if (mod->is_vmlinux || mod->from_dump) + continue; + + buf.pos = 0; + + err |= check_modname_len(mod); + err |= check_exports(mod); + + add_header(&buf, mod); + add_intree_flag(&buf, !external_module); + add_retpoline(&buf); + add_staging_flag(&buf, mod->name); + err |= add_versions(&buf, mod); + add_depends(&buf, mod); + add_moddevtable(&buf, mod); + add_srcversion(&buf, mod); + + sprintf(fname, "%s.mod.c", mod->name); + write_if_changed(&buf, fname); + } + + if (missing_namespace_deps) + write_namespace_deps_files(missing_namespace_deps); + + if (dump_write) + write_dump(dump_write); + if (sec_mismatch_count && sec_mismatch_fatal) + fatal("Section mismatches detected.\n" + "Set CONFIG_SECTION_MISMATCH_WARN_ONLY=y to allow them.\n"); + for (n = 0; n < SYMBOL_HASH_SIZE; n++) { + struct symbol *s; + + for (s = symbolhash[n]; s; s = s->next) { + if (s->is_static) + warn("\"%s\" [%s] is a static %s\n", + s->name, s->module->name, + export_str(s->export)); + } + } + + free(buf.p); + + return err; +} |