diff options
Diffstat (limited to 'scripts/mod/modpost.c')
| -rw-r--r-- | scripts/mod/modpost.c | 2210 |
1 files changed, 2210 insertions, 0 deletions
diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c new file mode 100644 index 00000000..c4e7d151 --- /dev/null +++ b/scripts/mod/modpost.c @@ -0,0 +1,2210 @@ +/* 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 <string.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'; + mod->is_dot_o = 1; + } + + /* 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 const char *sec_name(struct elf_info *elf, int 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; +} + +/** + * 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; + const char *secstrings; + unsigned int symtab_idx = ~0U, symtab_shndx_idx = ~0U; + + 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; + } + + 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, 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; + + if ((!is_vmlinux(mod->name) || mod->is_dot_o) && + strncmp(symname, "__ksymtab", 9) == 0) + 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: + 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 secindex) +{ + Elf_Shdr *sechdrs = elf->sechdrs; + return (void *)elf->hdr + + elf->sechdrs[elf->secindex_strings].sh_offset + + sechdrs[secindex].sh_name; +} + +static const char *sech_name(struct elf_info *elf, Elf_Shdr *sechdr) +{ + return (void *)elf->hdr + + elf->sechdrs[elf->secindex_strings].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*", + ".zdebug*", /* Compressed debug sections. */ + ".GCC-command-line", /* mn10300 */ + ".mdebug*", /* alpha, score, mips etc. */ + ".pdr", /* alpha, score, mips etc. */ + ".stab*", + ".note*", + ".got*", + ".toc*", + 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 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. + * 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 1a */ + if (strcmp(tosec, ".init.text") == 0 && + match(fromsec, data_sections) && + (strncmp(fromsym, "__param_ops_", strlen("__param_ops_")) == 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; + unsigned int relsym_secindex; + + if (relsym->st_name != 0) + return relsym; + + relsym_secindex = get_secindex(elf, relsym); + for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) { + if (get_secindex(elf, sym) != relsym_secindex) + continue; + if (ELF_ST_TYPE(sym->st_info) == STT_SECTION) + continue; + if (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 (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 + * .cpuinit.data => __cpudata + * .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 = 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 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"); +} + +/* + * 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; + + 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: + 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; + } + 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, get_secindex(elf, sym)); + 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; +} + +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 + +static int addend_arm_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r) +{ + unsigned int r_typ = ELF_R_TYPE(r->r_info); + + switch (r_typ) { + case R_ARM_ABS32: + /* From ARM ABI: (S + A) | T */ + r->r_addend = (int)(long) + (elf->symtab_start + ELF_R_SYM(r->r_info)); + break; + case R_ARM_PC24: + case R_ARM_CALL: + case R_ARM_JUMP24: + /* 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; + 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; + 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 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_intree_flag(struct buffer *b, int is_intree) +{ + if (is_intree) + buf_printf(b, "\nMODULE_INFO(intree, \"Y\");\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_intree_flag(&buf, !external_module); + 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; +} |