| /* 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 <stdio.h> |
| #include <ctype.h> |
| #include "modpost.h" |
| #include "../../include/generated/autoconf.h" |
| #include "../../include/linux/license.h" |
| |
| /* Some toolchains use a `_' prefix for all user symbols. */ |
| #ifdef CONFIG_SYMBOL_PREFIX |
| #define MODULE_SYMBOL_PREFIX CONFIG_SYMBOL_PREFIX |
| #else |
| #define MODULE_SYMBOL_PREFIX "" |
| #endif |
| |
| |
| /* Are we using CONFIG_MODVERSIONS? */ |
| int modversions = 0; |
| /* Warn about undefined symbols? (do so if we have vmlinux) */ |
| 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; |
| /* Warn about section mismatch in vmlinux if set to 1 */ |
| static int vmlinux_section_warnings = 1; |
| /* 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_verbose = 1; |
| |
| enum export { |
| export_plain, export_unused, export_gpl, |
| export_unused_gpl, export_gpl_future, export_unknown |
| }; |
| |
| #define PRINTF __attribute__ ((format (printf, 1, 2))) |
| |
| PRINTF void fatal(const char *fmt, ...) |
| { |
| va_list arglist; |
| |
| fprintf(stderr, "FATAL: "); |
| |
| va_start(arglist, fmt); |
| vfprintf(stderr, fmt, arglist); |
| va_end(arglist); |
| |
| exit(1); |
| } |
| |
| PRINTF void warn(const char *fmt, ...) |
| { |
| va_list arglist; |
| |
| fprintf(stderr, "WARNING: "); |
| |
| va_start(arglist, fmt); |
| vfprintf(stderr, fmt, arglist); |
| va_end(arglist); |
| } |
| |
| PRINTF void merror(const char *fmt, ...) |
| { |
| va_list arglist; |
| |
| fprintf(stderr, "ERROR: "); |
| |
| va_start(arglist, fmt); |
| vfprintf(stderr, fmt, arglist); |
| va_end(arglist); |
| } |
| |
| static int is_vmlinux(const char *modname) |
| { |
| const char *myname; |
| |
| myname = strrchr(modname, '/'); |
| if (myname) |
| myname++; |
| else |
| myname = modname; |
| |
| return (strcmp(myname, "vmlinux") == 0) || |
| (strcmp(myname, "vmlinux.o") == 0); |
| } |
| |
| void *do_nofail(void *ptr, const char *expr) |
| { |
| if (!ptr) |
| fatal("modpost: Memory allocation failure: %s.\n", expr); |
| |
| return ptr; |
| } |
| |
| /* A list of all modules we processed */ |
| static struct module *modules; |
| |
| static struct module *find_module(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(char *modname) |
| { |
| struct module *mod; |
| char *p, *s; |
| |
| mod = NOFAIL(malloc(sizeof(*mod))); |
| memset(mod, 0, sizeof(*mod)); |
| p = NOFAIL(strdup(modname)); |
| |
| /* strip trailing .o */ |
| s = strrchr(p, '.'); |
| if (s != NULL) |
| if (strcmp(s, ".o") == 0) |
| *s = '\0'; |
| |
| /* add to list */ |
| mod->name = p; |
| mod->gpl_compatible = -1; |
| mod->next = modules; |
| modules = mod; |
| |
| 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; |
| unsigned int weak:1; |
| unsigned int vmlinux:1; /* 1 if symbol is defined in vmlinux */ |
| unsigned int kernel:1; /* 1 if symbol is from kernel |
| * (only for external modules) **/ |
| unsigned int preloaded:1; /* 1 if symbol from Module.symvers */ |
| enum export export; /* Type of export */ |
| char name[0]; |
| }; |
| |
| 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; |
| 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; |
| struct symbol *new; |
| |
| hash = tdb_hash(name) % SYMBOL_HASH_SIZE; |
| new = symbolhash[hash] = alloc_symbol(name, 0, symbolhash[hash]); |
| new->module = module; |
| new->export = export; |
| return new; |
| } |
| |
| 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 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 enum export export_from_sec(struct elf_info *elf, Elf_Section 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; |
| } |
| |
| /** |
| * 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 (!s->preloaded) { |
| warn("%s: '%s' exported twice. Previous export " |
| "was in %s%s\n", mod->name, name, |
| s->module->name, |
| is_vmlinux(s->module->name) ?"":".ko"); |
| } else { |
| /* In case Modules.symvers was out of date */ |
| s->module = mod; |
| } |
| } |
| s->preloaded = 0; |
| s->vmlinux = is_vmlinux(mod->name); |
| s->kernel = 0; |
| s->export = export; |
| return s; |
| } |
| |
| static void sym_update_crc(const char *name, struct module *mod, |
| unsigned int crc, enum export export) |
| { |
| struct symbol *s = find_symbol(name); |
| |
| if (!s) |
| s = new_symbol(name, mod, export); |
| s->crc = crc; |
| s->crc_valid = 1; |
| } |
| |
| void *grab_file(const char *filename, unsigned long *size) |
| { |
| struct stat st; |
| void *map; |
| int fd; |
| |
| fd = open(filename, O_RDONLY); |
| if (fd < 0 || fstat(fd, &st) != 0) |
| return NULL; |
| |
| *size = st.st_size; |
| map = mmap(NULL, *size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0); |
| close(fd); |
| |
| if (map == MAP_FAILED) |
| return NULL; |
| return map; |
| } |
| |
| /** |
| * Return a copy of the next line in a mmap'ed file. |
| * spaces in the beginning of the line is trimmed away. |
| * Return a pointer to a static buffer. |
| **/ |
| char *get_next_line(unsigned long *pos, void *file, unsigned long size) |
| { |
| static char line[4096]; |
| int skip = 1; |
| size_t len = 0; |
| signed char *p = (signed char *)file + *pos; |
| char *s = line; |
| |
| for (; *pos < size ; (*pos)++) { |
| if (skip && isspace(*p)) { |
| p++; |
| continue; |
| } |
| skip = 0; |
| if (*p != '\n' && (*pos < size)) { |
| len++; |
| *s++ = *p++; |
| if (len > 4095) |
| break; /* Too long, stop */ |
| } else { |
| /* End of string */ |
| *s = '\0'; |
| return line; |
| } |
| } |
| /* End of buffer */ |
| return NULL; |
| } |
| |
| void release_file(void *file, unsigned long 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; |
| |
| hdr = grab_file(filename, &info->size); |
| if (!hdr) { |
| 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=%lu\n", (unsigned long)hdr->e_shoff, |
| filename, info->size); |
| return 0; |
| } |
| |
| /* Fix endianness in section headers */ |
| for (i = 0; i < hdr->e_shnum; 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. */ |
| for (i = 1; i < hdr->e_shnum; i++) { |
| const char *secstrings |
| = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset; |
| 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) |
| continue; |
| |
| info->symtab_start = (void *)hdr + sechdrs[i].sh_offset; |
| info->symtab_stop = (void *)hdr + sechdrs[i].sh_offset |
| + sechdrs[i].sh_size; |
| info->strtab = (void *)hdr + |
| sechdrs[sechdrs[i].sh_link].sh_offset; |
| } |
| 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); |
| } |
| 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, MODULE_SYMBOL_PREFIX "__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 (strncmp(symname, "_restgpr_", sizeof("_restgpr_") - 1) == 0 || |
| strncmp(symname, "_savegpr_", sizeof("_savegpr_") - 1) == 0 || |
| strncmp(symname, "_rest32gpr_", sizeof("_rest32gpr_") - 1) == 0 || |
| strncmp(symname, "_save32gpr_", sizeof("_save32gpr_") - 1) == 0) |
| return 1; |
| if (info->hdr->e_machine == EM_PPC64) |
| /* Special register function linked on all modules during final link of .ko */ |
| if (strncmp(symname, "_restgpr0_", sizeof("_restgpr0_") - 1) == 0 || |
| strncmp(symname, "_savegpr0_", sizeof("_savegpr0_") - 1) == 0) |
| return 1; |
| /* Do not ignore this symbol */ |
| return 0; |
| } |
| |
| #define CRC_PFX MODULE_SYMBOL_PREFIX "__crc_" |
| #define KSYMTAB_PFX MODULE_SYMBOL_PREFIX "__ksymtab_" |
| |
| static void handle_modversions(struct module *mod, struct elf_info *info, |
| Elf_Sym *sym, const char *symname) |
| { |
| unsigned int crc; |
| enum export export = export_from_sec(info, sym->st_shndx); |
| |
| switch (sym->st_shndx) { |
| case SHN_COMMON: |
| warn("\"%s\" [%s] is COMMON symbol\n", symname, mod->name); |
| break; |
| case SHN_ABS: |
| /* CRC'd symbol */ |
| if (strncmp(symname, CRC_PFX, strlen(CRC_PFX)) == 0) { |
| crc = (unsigned int) sym->st_value; |
| sym_update_crc(symname + strlen(CRC_PFX), mod, crc, |
| export); |
| } |
| 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; |
| /* cope with newer glibc (2.3.4 or higher) STT_ definition in elf.h */ |
| #if defined(STT_REGISTER) || defined(STT_SPARC_REGISTER) |
| /* add compatibility with older glibc */ |
| #ifndef STT_SPARC_REGISTER |
| #define STT_SPARC_REGISTER STT_REGISTER |
| #endif |
| 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 = strdup(symname); |
| munged[0] = '_'; |
| munged[1] = toupper(munged[1]); |
| symname = munged; |
| } |
| } |
| #endif |
| |
| if (memcmp(symname, MODULE_SYMBOL_PREFIX, |
| strlen(MODULE_SYMBOL_PREFIX)) == 0) { |
| mod->unres = |
| alloc_symbol(symname + |
| strlen(MODULE_SYMBOL_PREFIX), |
| ELF_ST_BIND(sym->st_info) == STB_WEAK, |
| mod->unres); |
| } |
| break; |
| default: |
| /* All exported symbols */ |
| if (strncmp(symname, KSYMTAB_PFX, strlen(KSYMTAB_PFX)) == 0) { |
| sym_add_exported(symname + strlen(KSYMTAB_PFX), mod, |
| export); |
| } |
| if (strcmp(symname, MODULE_SYMBOL_PREFIX "init_module") == 0) |
| mod->has_init = 1; |
| if (strcmp(symname, MODULE_SYMBOL_PREFIX "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(void *modinfo, unsigned long modinfo_len, |
| const char *tag, char *info) |
| { |
| char *p; |
| unsigned int taglen = strlen(tag); |
| unsigned long size = modinfo_len; |
| |
| if (info) { |
| size -= info - (char *)modinfo; |
| modinfo = next_string(info, &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(void *modinfo, unsigned long modinfo_len, |
| const char *tag) |
| |
| { |
| return get_next_modinfo(modinfo, modinfo_len, 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)"; |
| } |
| |
| static const char *sec_name(struct elf_info *elf, int shndx) |
| { |
| Elf_Shdr *sechdrs = elf->sechdrs; |
| return (void *)elf->hdr + |
| elf->sechdrs[elf->hdr->e_shstrndx].sh_offset + |
| sechdrs[shndx].sh_name; |
| } |
| |
| static const char *sech_name(struct elf_info *elf, Elf_Shdr *sechdr) |
| { |
| return (void *)elf->hdr + |
| elf->sechdrs[elf->hdr->e_shstrndx].sh_offset + |
| sechdr->sh_name; |
| } |
| |
| /* if sym is empty or point to a string |
| * like ".[0-9]+" then return 1. |
| * This is the optional prefix added by ld to some sections |
| */ |
| static int number_prefix(const char *sym) |
| { |
| if (*sym++ == '\0') |
| return 1; |
| if (*sym != '.') |
| return 0; |
| do { |
| char c = *sym++; |
| if (c < '0' || c > '9') |
| return 0; |
| } while (*sym); |
| return 1; |
| } |
| |
| /* 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 equal to "foo" or "foo.1" |
| * where the '1' can be any number including several digits. |
| * The $ syntax is for sections where ld append a dot number |
| * to make section name unique. |
| */ |
| 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 == '*') { |
| if (strrcmp(sym, p + 1) == 0) |
| return 1; |
| } |
| /* "foo*" */ |
| else if (*endp == '*') { |
| if (strncmp(sym, p, strlen(p) - 1) == 0) |
| return 1; |
| } |
| /* "foo$" */ |
| else if (*endp == '$') { |
| if (strncmp(sym, p, strlen(p) - 1) == 0) { |
| if (number_prefix(sym + strlen(p) - 1)) |
| 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 *section_white_list[] = |
| { |
| ".comment*", |
| ".debug*", |
| ".mdebug*", /* alpha, score, mips etc. */ |
| ".pdr", /* alpha, score, mips etc. */ |
| ".stab*", |
| ".note*", |
| ".got*", |
| ".toc*", |
| ".gnu.linkonce.arcext*", |
| 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$", ".init.rodata$", \ |
| ".devinit.rodata$", ".cpuinit.rodata$", ".meminit.rodata$" \ |
| ".init.data$", ".devinit.data$", ".cpuinit.data$", ".meminit.data$" |
| #define ALL_EXIT_DATA_SECTIONS \ |
| ".exit.data$", ".devexit.data$", ".cpuexit.data$", ".memexit.data$" |
| |
| #define ALL_INIT_TEXT_SECTIONS \ |
| ".init.text$", ".devinit.text$", ".cpuinit.text$", ".meminit.text$" |
| #define ALL_EXIT_TEXT_SECTIONS \ |
| ".exit.text$", ".devexit.text$", ".cpuexit.text$", ".memexit.text$" |
| |
| #define ALL_XXXINIT_SECTIONS DEV_INIT_SECTIONS, CPU_INIT_SECTIONS, \ |
| MEM_INIT_SECTIONS |
| #define ALL_XXXEXIT_SECTIONS DEV_EXIT_SECTIONS, CPU_EXIT_SECTIONS, \ |
| MEM_EXIT_SECTIONS |
| |
| #define ALL_INIT_SECTIONS INIT_SECTIONS, ALL_XXXINIT_SECTIONS |
| #define ALL_EXIT_SECTIONS EXIT_SECTIONS, ALL_XXXEXIT_SECTIONS |
| |
| #define DATA_SECTIONS ".data$", ".data.rel$" |
| #define TEXT_SECTIONS ".text$" |
| |
| #define INIT_SECTIONS ".init.*" |
| #define DEV_INIT_SECTIONS ".devinit.*" |
| #define CPU_INIT_SECTIONS ".cpuinit.*" |
| #define MEM_INIT_SECTIONS ".meminit.*" |
| |
| #define EXIT_SECTIONS ".exit.*" |
| #define DEV_EXIT_SECTIONS ".devexit.*" |
| #define CPU_EXIT_SECTIONS ".cpuexit.*" |
| #define MEM_EXIT_SECTIONS ".memexit.*" |
| |
| /* init data sections */ |
| static const char *init_data_sections[] = { ALL_INIT_DATA_SECTIONS, NULL }; |
| |
| /* all init sections */ |
| static const char *init_sections[] = { ALL_INIT_SECTIONS, NULL }; |
| |
| /* All init and exit sections (code + data) */ |
| static const char *init_exit_sections[] = |
| {ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS, NULL }; |
| |
| /* data section */ |
| static const char *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 *head_sections[] = { ".head.text*", NULL }; |
| static const char *linker_symbols[] = |
| { "__init_begin", "_sinittext", "_einittext", 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, |
| }; |
| |
| struct sectioncheck { |
| const char *fromsec[20]; |
| const char *tosec[20]; |
| enum mismatch mismatch; |
| const char *symbol_white_list[20]; |
| }; |
| |
| const struct sectioncheck sectioncheck[] = { |
| /* Do not reference init/exit code/data from |
| * normal code and data |
| */ |
| { |
| .fromsec = { TEXT_SECTIONS, NULL }, |
| .tosec = { ALL_INIT_SECTIONS, NULL }, |
| .mismatch = TEXT_TO_ANY_INIT, |
| .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, |
| }, |
| { |
| .fromsec = { DATA_SECTIONS, NULL }, |
| .tosec = { ALL_XXXINIT_SECTIONS, NULL }, |
| .mismatch = DATA_TO_ANY_INIT, |
| .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, |
| }, |
| { |
| .fromsec = { DATA_SECTIONS, NULL }, |
| .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 }, |
| .tosec = { ALL_EXIT_SECTIONS, NULL }, |
| .mismatch = TEXT_TO_ANY_EXIT, |
| .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, |
| }, |
| { |
| .fromsec = { DATA_SECTIONS, NULL }, |
| .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 devinit/cpuinit/meminit code/data */ |
| { |
| .fromsec = { ALL_XXXINIT_SECTIONS, NULL }, |
| .tosec = { INIT_SECTIONS, NULL }, |
| .mismatch = XXXINIT_TO_SOME_INIT, |
| .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, |
| }, |
| /* Do not reference cpuinit code/data from meminit code/data */ |
| { |
| .fromsec = { MEM_INIT_SECTIONS, NULL }, |
| .tosec = { CPU_INIT_SECTIONS, NULL }, |
| .mismatch = XXXINIT_TO_SOME_INIT, |
| .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, |
| }, |
| /* Do not reference meminit code/data from cpuinit code/data */ |
| { |
| .fromsec = { CPU_INIT_SECTIONS, NULL }, |
| .tosec = { MEM_INIT_SECTIONS, NULL }, |
| .mismatch = XXXINIT_TO_SOME_INIT, |
| .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, |
| }, |
| /* Do not reference exit code/data from devexit/cpuexit/memexit code/data */ |
| { |
| .fromsec = { ALL_XXXEXIT_SECTIONS, NULL }, |
| .tosec = { EXIT_SECTIONS, NULL }, |
| .mismatch = XXXEXIT_TO_SOME_EXIT, |
| .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, |
| }, |
| /* Do not reference cpuexit code/data from memexit code/data */ |
| { |
| .fromsec = { MEM_EXIT_SECTIONS, NULL }, |
| .tosec = { CPU_EXIT_SECTIONS, NULL }, |
| .mismatch = XXXEXIT_TO_SOME_EXIT, |
| .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, |
| }, |
| /* Do not reference memexit code/data from cpuexit code/data */ |
| { |
| .fromsec = { CPU_EXIT_SECTIONS, NULL }, |
| .tosec = { MEM_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 }, |
| .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 }, |
| .tosec = { ALL_INIT_SECTIONS, NULL }, |
| .mismatch = ANY_EXIT_TO_ANY_INIT, |
| .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, |
| }, |
| /* Do not export init/exit functions or data */ |
| { |
| .fromsec = { "__ksymtab*", NULL }, |
| .tosec = { INIT_SECTIONS, EXIT_SECTIONS, NULL }, |
| .mismatch = EXPORT_TO_INIT_EXIT, |
| .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL }, |
| } |
| }; |
| |
| 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]; |
| |
| for (i = 0; i < elems; i++) { |
| if (match(fromsec, check->fromsec) && |
| match(tosec, check->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 2: |
| * Many drivers utilise a *driver container with references to |
| * add, remove, probe functions etc. |
| * These functions may often be marked __devinit and we do not want to |
| * warn here. |
| * 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 |
| * |
| **/ |
| 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) && |
| (strncmp(fromsym, "__param", strlen("__param")) == 0)) |
| 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; |
| |
| return 1; |
| } |
| |
| /** |
| * 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; |
| |
| if (relsym->st_name != 0) |
| return relsym; |
| for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) { |
| if (sym->st_shndx != relsym->st_shndx) |
| continue; |
| if (ELF_ST_TYPE(sym->st_info) == STT_SECTION) |
| 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; |
| } |
| |
| static inline int is_arm_mapping_symbol(const char *str) |
| { |
| return str[0] == '$' && strchr("atd", str[1]) |
| && (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 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 (sym->st_shndx >= SHN_LORESERVE) |
| continue; |
| symsec = sec_name(elf, sym->st_shndx); |
| 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 |
| * .cpuinit.data => __cpudata |
| * .memexitconst => __memconst |
| * etc. |
| */ |
| static char *sec2annotation(const char *s) |
| { |
| if (match(s, init_exit_sections)) { |
| char *p = 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; /* we leak her but we do not care */ |
| } else { |
| return ""; |
| } |
| } |
| |
| static int is_function(Elf_Sym *sym) |
| { |
| if (sym) |
| return ELF_ST_TYPE(sym->st_info) == STT_FUNC; |
| else |
| return -1; |
| } |
| |
| /* |
| * 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; |
| |
| switch (from_is_func) { |
| case 0: from = "variable"; from_p = ""; break; |
| case 1: from = "function"; from_p = "()"; break; |
| default: from = "(unknown reference)"; from_p = ""; break; |
| } |
| switch (to_is_func) { |
| case 0: to = "variable"; to_p = ""; break; |
| case 1: to = "function"; to_p = "()"; break; |
| default: to = "(unknown reference)"; to_p = ""; break; |
| } |
| |
| sec_mismatch_count++; |
| if (!sec_mismatch_verbose) |
| return; |
| |
| 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: |
| 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", |
| sec2annotation(fromsec), fromsym, |
| to, sec2annotation(tosec), tosym, to_p, |
| fromsym, sec2annotation(tosec), tosym); |
| break; |
| case DATA_TO_ANY_INIT: { |
| const char *const *s = mismatch->symbol_white_list; |
| 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, sec2annotation(tosec), tosym, to_p); |
| while (*s) |
| fprintf(stderr, "%s, ", *s++); |
| fprintf(stderr, "\n"); |
| break; |
| } |
| case TEXT_TO_ANY_EXIT: |
| 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, sec2annotation(tosec), tosym); |
| break; |
| case DATA_TO_ANY_EXIT: { |
| const char *const *s = mismatch->symbol_white_list; |
| 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, sec2annotation(tosec), tosym, to_p); |
| while (*s) |
| fprintf(stderr, "%s, ", *s++); |
| fprintf(stderr, "\n"); |
| break; |
| } |
| case XXXINIT_TO_SOME_INIT: |
| case XXXEXIT_TO_SOME_EXIT: |
| 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, sec2annotation(fromsec), fromsym, from_p, |
| to, sec2annotation(tosec), tosym, to_p, |
| tosym, fromsym, tosym); |
| break; |
| case ANY_INIT_TO_ANY_EXIT: |
| 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, sec2annotation(fromsec), fromsym, from_p, |
| to, sec2annotation(tosec), tosym, to_p, |
| sec2annotation(tosec), tosym, to_p); |
| break; |
| case ANY_EXIT_TO_ANY_INIT: |
| 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, sec2annotation(fromsec), fromsym, from_p, |
| to, sec2annotation(tosec), tosym, to_p, |
| sec2annotation(tosec), tosym, to_p); |
| break; |
| case EXPORT_TO_INIT_EXIT: |
| 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, sec2annotation(tosec), sec2annotation(tosec), tosym); |
| break; |
| } |
| fprintf(stderr, "\n"); |
| } |
| |
| static void check_section_mismatch(const char *modname, struct elf_info *elf, |
| Elf_Rela *r, Elf_Sym *sym, const char *fromsec) |
| { |
| const char *tosec; |
| const struct sectioncheck *mismatch; |
| |
| tosec = sec_name(elf, sym->st_shndx); |
| mismatch = section_mismatch(fromsec, tosec); |
| if (mismatch) { |
| 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); |
| 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 unsigned int *reloc_location(struct elf_info *elf, |
| Elf_Shdr *sechdr, Elf_Rela *r) |
| { |
| Elf_Shdr *sechdrs = elf->sechdrs; |
| int section = sechdr->sh_info; |
| |
| return (void *)elf->hdr + sechdrs[section].sh_offset + |
| r->r_offset - sechdrs[section].sh_addr; |
| } |
| |
| 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; |
| } |
| |
| 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: |
| /* 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 (sym->st_shndx >= SHN_LORESERVE) |
| continue; |
| 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 (sym->st_shndx >= SHN_LORESERVE) |
| continue; |
| 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 intialized. |
| * 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->hdr->e_shnum; 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 void read_symbols(char *modname) |
| { |
| const char *symname; |
| char *version; |
| char *license; |
| struct module *mod; |
| struct elf_info info = { }; |
| Elf_Sym *sym; |
| |
| if (!parse_elf(&info, modname)) |
| return; |
| |
| mod = new_module(modname); |
| |
| /* When there's no vmlinux, don't print warnings about |
| * unresolved symbols (since there'll be too many ;) */ |
| if (is_vmlinux(modname)) { |
| have_vmlinux = 1; |
| mod->skip = 1; |
| } |
| |
| license = get_modinfo(info.modinfo, info.modinfo_len, "license"); |
| if (info.modinfo && !license && !is_vmlinux(modname)) |
| warn("modpost: missing MODULE_LICENSE() in %s\n" |
| "see include/linux/module.h for " |
| "more information\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.modinfo, info.modinfo_len, |
| "license", license); |
| } |
| |
| for (sym = info.symtab_start; sym < info.symtab_stop; sym++) { |
| symname = info.strtab + sym->st_name; |
| |
| handle_modversions(mod, &info, sym, symname); |
| handle_moddevtable(mod, &info, sym, symname); |
| } |
| if (!is_vmlinux(modname) || |
| (is_vmlinux(modname) && vmlinux_section_warnings)) |
| check_sec_ref(mod, modname, &info); |
| |
| version = get_modinfo(info.modinfo, info.modinfo_len, "version"); |
| if (version) |
| maybe_frob_rcs_version(modname, version, info.modinfo, |
| version - (char *)info.hdr); |
| if (version || (all_versions && !is_vmlinux(modname))) |
| 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); |
| } |
| |
| #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 = 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) |
| { |
| const char *e = is_vmlinux(m) ?"":".ko"; |
| |
| switch (exp) { |
| case export_gpl: |
| fatal("modpost: GPL-incompatible module %s%s " |
| "uses GPL-only symbol '%s'\n", m, e, s); |
| break; |
| case export_unused_gpl: |
| fatal("modpost: GPL-incompatible module %s%s " |
| "uses GPL-only symbol marked UNUSED '%s'\n", m, e, s); |
| break; |
| case export_gpl_future: |
| warn("modpost: GPL-incompatible module %s%s " |
| "uses future GPL-only symbol '%s'\n", m, e, 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) |
| { |
| const char *e = is_vmlinux(m) ?"":".ko"; |
| |
| switch (exp) { |
| case export_unused: |
| case export_unused_gpl: |
| warn("modpost: module %s%s " |
| "uses symbol '%s' marked UNUSED\n", m, e, s); |
| break; |
| default: |
| /* ignore */ |
| break; |
| } |
| } |
| |
| static void check_exports(struct module *mod) |
| { |
| struct symbol *s, *exp; |
| |
| for (s = mod->unres; s; s = s->next) { |
| const char *basename; |
| exp = find_symbol(s->name); |
| if (!exp || exp->module == mod) |
| continue; |
| basename = strrchr(mod->name, '/'); |
| if (basename) |
| basename++; |
| else |
| basename = mod->name; |
| if (!mod->gpl_compatible) |
| check_for_gpl_usage(exp->export, basename, exp->name); |
| check_for_unused(exp->export, basename, exp->name); |
| } |
| } |
| |
| /** |
| * Header for the generated file |
| **/ |
| static void add_header(struct buffer *b, struct module *mod) |
| { |
| buf_printf(b, "#include <linux/module.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, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n"); |
| buf_printf(b, "\n"); |
| buf_printf(b, "struct module __this_module\n"); |
| buf_printf(b, "__attribute__((section(\".gnu.linkonce.this_module\"))) = {\n"); |
| buf_printf(b, " .name = KBUILD_MODNAME,\n"); |
| if (mod->has_init) |
| buf_printf(b, " .init = init_module,\n"); |
| if (mod->has_cleanup) |
| buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n" |
| " .exit = cleanup_module,\n" |
| "#endif\n"); |
| buf_printf(b, " .arch = MODULE_ARCH_INIT,\n"); |
| buf_printf(b, "};\n"); |
| } |
| |
| static void add_staging_flag(struct buffer *b, const char *name) |
| { |
| static const char *staging_dir = "drivers/staging"; |
| |
| if (strncmp(staging_dir, name, strlen(staging_dir)) == 0) |
| 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) { |
| if (have_vmlinux && !s->weak) { |
| if (warn_unresolved) { |
| warn("\"%s\" [%s.ko] undefined!\n", |
| s->name, mod->name); |
| } else { |
| merror("\"%s\" [%s.ko] undefined!\n", |
| s->name, mod->name); |
| err = 1; |
| } |
| } |
| 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\n"); |
| buf_printf(b, "__attribute__((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; |
| } |
| 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 module *modules) |
| { |
| struct symbol *s; |
| struct module *m; |
| int first = 1; |
| |
| for (m = modules; m; m = m->next) |
| m->seen = is_vmlinux(m->name); |
| |
| buf_printf(b, "\n"); |
| buf_printf(b, "static const char __module_depends[]\n"); |
| buf_printf(b, "__used\n"); |
| buf_printf(b, "__attribute__((section(\".modinfo\"))) =\n"); |
| buf_printf(b, "\"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_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: |
| file = fopen(fname, "w"); |
| if (!file) { |
| perror(fname); |
| exit(1); |
| } |
| if (fwrite(b->p, 1, b->pos, file) != b->pos) { |
| perror(fname); |
| exit(1); |
| } |
| fclose(file); |
| } |
| |
| /* parse Module.symvers file. line format: |
| * 0x12345678<tab>symbol<tab>module[[<tab>export]<tab>something] |
| **/ |
| static void read_dump(const char *fname, unsigned int kernel) |
| { |
| unsigned long size, pos = 0; |
| void *file = grab_file(fname, &size); |
| char *line; |
| |
| if (!file) |
| /* No symbol versions, silently ignore */ |
| return; |
| |
| while ((line = get_next_line(&pos, file, size))) { |
| char *symname, *modname, *d, *export, *end; |
| 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')) != NULL) |
| *export++ = '\0'; |
| if (export && ((end = strchr(export, '\t')) != NULL)) |
| *end = '\0'; |
| crc = strtoul(line, &d, 16); |
| if (*symname == '\0' || *modname == '\0' || *d != '\0') |
| goto fail; |
| mod = find_module(modname); |
| if (!mod) { |
| if (is_vmlinux(modname)) |
| have_vmlinux = 1; |
| mod = new_module(modname); |
| mod->skip = 1; |
| } |
| s = sym_add_exported(symname, mod, export_no(export)); |
| s->kernel = kernel; |
| s->preloaded = 1; |
| sym_update_crc(symname, mod, crc, export_no(export)); |
| } |
| return; |
| fail: |
| fatal("parse error in symbol dump file\n"); |
| } |
| |
| /* For normal builds always dump all symbols. |
| * For external modules only dump symbols |
| * that are not read from kernel Module.symvers. |
| **/ |
| static int dump_sym(struct symbol *sym) |
| { |
| if (!external_module) |
| return 1; |
| if (sym->vmlinux || sym->kernel) |
| return 0; |
| return 1; |
| } |
| |
| static void write_dump(const char *fname) |
| { |
| struct buffer buf = { }; |
| struct symbol *symbol; |
| int n; |
| |
| for (n = 0; n < SYMBOL_HASH_SIZE ; n++) { |
| symbol = symbolhash[n]; |
| while (symbol) { |
| if (dump_sym(symbol)) |
| buf_printf(&buf, "0x%08x\t%s\t%s\t%s\n", |
| symbol->crc, symbol->name, |
| symbol->module->name, |
| export_str(symbol->export)); |
| symbol = symbol->next; |
| } |
| } |
| write_if_changed(&buf, fname); |
| } |
| |
| struct ext_sym_list { |
| struct ext_sym_list *next; |
| const char *file; |
| }; |
| |
| int main(int argc, char **argv) |
| { |
| struct module *mod; |
| struct buffer buf = { }; |
| char *kernel_read = NULL, *module_read = NULL; |
| char *dump_write = NULL; |
| int opt; |
| int err; |
| struct ext_sym_list *extsym_iter; |
| struct ext_sym_list *extsym_start = NULL; |
| |
| while ((opt = getopt(argc, argv, "i:I:e:cmsSo:awM:K:")) != -1) { |
| switch (opt) { |
| case 'i': |
| kernel_read = optarg; |
| break; |
| case 'I': |
| module_read = optarg; |
| external_module = 1; |
| break; |
| case 'c': |
| cross_build = 1; |
| break; |
| case 'e': |
| external_module = 1; |
| extsym_iter = |
| NOFAIL(malloc(sizeof(*extsym_iter))); |
| extsym_iter->next = extsym_start; |
| extsym_iter->file = optarg; |
| extsym_start = extsym_iter; |
| break; |
| case 'm': |
| modversions = 1; |
| break; |
| case 'o': |
| dump_write = optarg; |
| break; |
| case 'a': |
| all_versions = 1; |
| break; |
| case 's': |
| vmlinux_section_warnings = 0; |
| break; |
| case 'S': |
| sec_mismatch_verbose = 0; |
| break; |
| case 'w': |
| warn_unresolved = 1; |
| break; |
| default: |
| exit(1); |
| } |
| } |
| |
| if (kernel_read) |
| read_dump(kernel_read, 1); |
| if (module_read) |
| read_dump(module_read, 0); |
| while (extsym_start) { |
| read_dump(extsym_start->file, 0); |
| extsym_iter = extsym_start->next; |
| free(extsym_start); |
| extsym_start = extsym_iter; |
| } |
| |
| while (optind < argc) |
| read_symbols(argv[optind++]); |
| |
| for (mod = modules; mod; mod = mod->next) { |
| if (mod->skip) |
| continue; |
| check_exports(mod); |
| } |
| |
| err = 0; |
| |
| for (mod = modules; mod; mod = mod->next) { |
| char fname[strlen(mod->name) + 10]; |
| |
| if (mod->skip) |
| continue; |
| |
| buf.pos = 0; |
| |
| add_header(&buf, mod); |
| add_staging_flag(&buf, mod->name); |
| err |= add_versions(&buf, mod); |
| add_depends(&buf, mod, modules); |
| add_moddevtable(&buf, mod); |
| add_srcversion(&buf, mod); |
| |
| sprintf(fname, "%s.mod.c", mod->name); |
| write_if_changed(&buf, fname); |
| } |
| |
| if (dump_write) |
| write_dump(dump_write); |
| if (sec_mismatch_count && !sec_mismatch_verbose) |
| warn("modpost: Found %d section mismatch(es).\n" |
| "To see full details build your kernel with:\n" |
| "'make CONFIG_DEBUG_SECTION_MISMATCH=y'\n", |
| sec_mismatch_count); |
| |
| return err; |
| } |