diff options
Diffstat (limited to 'scripts/mod/modpost.c')
| -rw-r--r-- | scripts/mod/modpost.c | 2371 |
1 files changed, 2371 insertions, 0 deletions
diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c new file mode 100644 index 000000000..e6be7fc26 --- /dev/null +++ b/scripts/mod/modpost.c @@ -0,0 +1,2371 @@ +/* Postprocess module symbol versions + * + * Copyright 2003 Kai Germaschewski + * Copyright 2002-2004 Rusty Russell, IBM Corporation + * Copyright 2006-2008 Sam Ravnborg + * Based in part on module-init-tools/depmod.c,file2alias + * + * This software may be used and distributed according to the terms + * of the GNU General Public License, incorporated herein by reference. + * + * Usage: modpost vmlinux module1.o module2.o ... + */ + +#define _GNU_SOURCE +#include <elf.h> +#include <fnmatch.h> +#include <stdio.h> +#include <ctype.h> +#include <string.h> +#include <limits.h> +#include <stdbool.h> +#include <errno.h> +#include "modpost.h" +#include "../../include/linux/license.h" + +/* Are we using CONFIG_MODVERSIONS? */ +static bool modversions; +/* Is CONFIG_MODULE_SRCVERSION_ALL set? */ +static bool all_versions; +/* If we are modposting external module set to 1 */ +static bool external_module; +/* Only warn about unresolved symbols */ +static bool warn_unresolved; + +static int sec_mismatch_count; +static bool sec_mismatch_warn_only = true; +/* ignore missing files */ +static bool ignore_missing_files; +/* If set to 1, only warn (instead of error) about missing ns imports */ +static bool allow_missing_ns_imports; + +static bool error_occurred; + +/* + * Cut off the warnings when there are too many. This typically occurs when + * vmlinux is missing. ('make modules' without building vmlinux.) + */ +#define MAX_UNRESOLVED_REPORTS 10 +static unsigned int nr_unresolved; + +/* In kernel, this size is defined in linux/module.h; + * here we use Elf_Addr instead of long for covering cross-compile + */ + +#define MODULE_NAME_LEN (64 - sizeof(Elf_Addr)) + +void __attribute__((format(printf, 2, 3))) +modpost_log(enum loglevel loglevel, const char *fmt, ...) +{ + va_list arglist; + + switch (loglevel) { + case LOG_WARN: + fprintf(stderr, "WARNING: "); + break; + case LOG_ERROR: + fprintf(stderr, "ERROR: "); + break; + case LOG_FATAL: + fprintf(stderr, "FATAL: "); + break; + default: /* invalid loglevel, ignore */ + break; + } + + fprintf(stderr, "modpost: "); + + va_start(arglist, fmt); + vfprintf(stderr, fmt, arglist); + va_end(arglist); + + if (loglevel == LOG_FATAL) + exit(1); + if (loglevel == LOG_ERROR) + error_occurred = true; +} + +static inline bool strends(const char *str, const char *postfix) +{ + if (strlen(str) < strlen(postfix)) + return false; + + return strcmp(str + strlen(str) - strlen(postfix), postfix) == 0; +} + +void *do_nofail(void *ptr, const char *expr) +{ + if (!ptr) + fatal("Memory allocation failure: %s.\n", expr); + + return ptr; +} + +char *read_text_file(const char *filename) +{ + struct stat st; + size_t nbytes; + int fd; + char *buf; + + fd = open(filename, O_RDONLY); + if (fd < 0) { + perror(filename); + exit(1); + } + + if (fstat(fd, &st) < 0) { + perror(filename); + exit(1); + } + + buf = NOFAIL(malloc(st.st_size + 1)); + + nbytes = st.st_size; + + while (nbytes) { + ssize_t bytes_read; + + bytes_read = read(fd, buf, nbytes); + if (bytes_read < 0) { + perror(filename); + exit(1); + } + + nbytes -= bytes_read; + } + buf[st.st_size] = '\0'; + + close(fd); + + return buf; +} + +char *get_line(char **stringp) +{ + char *orig = *stringp, *next; + + /* do not return the unwanted extra line at EOF */ + if (!orig || *orig == '\0') + return NULL; + + /* don't use strsep here, it is not available everywhere */ + next = strchr(orig, '\n'); + if (next) + *next++ = '\0'; + + *stringp = next; + + return orig; +} + +/* A list of all modules we processed */ +LIST_HEAD(modules); + +static struct module *find_module(const char *modname) +{ + struct module *mod; + + list_for_each_entry(mod, &modules, list) { + if (strcmp(mod->name, modname) == 0) + return mod; + } + return NULL; +} + +static struct module *new_module(const char *name, size_t namelen) +{ + struct module *mod; + + mod = NOFAIL(malloc(sizeof(*mod) + namelen + 1)); + memset(mod, 0, sizeof(*mod)); + + INIT_LIST_HEAD(&mod->exported_symbols); + INIT_LIST_HEAD(&mod->unresolved_symbols); + INIT_LIST_HEAD(&mod->missing_namespaces); + INIT_LIST_HEAD(&mod->imported_namespaces); + + memcpy(mod->name, name, namelen); + mod->name[namelen] = '\0'; + mod->is_vmlinux = (strcmp(mod->name, "vmlinux") == 0); + + /* + * Set mod->is_gpl_compatible to true by default. If MODULE_LICENSE() + * is missing, do not check the use for EXPORT_SYMBOL_GPL() becasue + * modpost will exit wiht error anyway. + */ + mod->is_gpl_compatible = true; + + list_add_tail(&mod->list, &modules); + + return mod; +} + +/* A hash of all exported symbols, + * struct symbol is also used for lists of unresolved symbols */ + +#define SYMBOL_HASH_SIZE 1024 + +struct symbol { + struct symbol *next; + struct list_head list; /* link to module::exported_symbols or module::unresolved_symbols */ + struct module *module; + char *namespace; + unsigned int crc; + bool crc_valid; + bool weak; + bool is_gpl_only; /* exported by EXPORT_SYMBOL_GPL */ + char name[]; +}; + +static struct symbol *symbolhash[SYMBOL_HASH_SIZE]; + +/* This is based on the hash algorithm from gdbm, via tdb */ +static inline unsigned int tdb_hash(const char *name) +{ + unsigned value; /* Used to compute the hash value. */ + unsigned i; /* Used to cycle through random values. */ + + /* Set the initial value from the key size. */ + for (value = 0x238F13AF * strlen(name), i = 0; name[i]; i++) + value = (value + (((unsigned char *)name)[i] << (i*5 % 24))); + + return (1103515243 * value + 12345); +} + +/** + * Allocate a new symbols for use in the hash of exported symbols or + * the list of unresolved symbols per module + **/ +static struct symbol *alloc_symbol(const char *name) +{ + struct symbol *s = NOFAIL(malloc(sizeof(*s) + strlen(name) + 1)); + + memset(s, 0, sizeof(*s)); + strcpy(s->name, name); + + return s; +} + +/* For the hash of exported symbols */ +static void hash_add_symbol(struct symbol *sym) +{ + unsigned int hash; + + hash = tdb_hash(sym->name) % SYMBOL_HASH_SIZE; + sym->next = symbolhash[hash]; + symbolhash[hash] = sym; +} + +static void sym_add_unresolved(const char *name, struct module *mod, bool weak) +{ + struct symbol *sym; + + sym = alloc_symbol(name); + sym->weak = weak; + + list_add_tail(&sym->list, &mod->unresolved_symbols); +} + +static struct symbol *sym_find_with_module(const char *name, struct module *mod) +{ + struct symbol *s; + + /* For our purposes, .foo matches foo. PPC64 needs this. */ + if (name[0] == '.') + name++; + + for (s = symbolhash[tdb_hash(name) % SYMBOL_HASH_SIZE]; s; s = s->next) { + if (strcmp(s->name, name) == 0 && (!mod || s->module == mod)) + return s; + } + return NULL; +} + +static struct symbol *find_symbol(const char *name) +{ + return sym_find_with_module(name, NULL); +} + +struct namespace_list { + struct list_head list; + char namespace[]; +}; + +static bool contains_namespace(struct list_head *head, const char *namespace) +{ + struct namespace_list *list; + + list_for_each_entry(list, head, list) { + if (!strcmp(list->namespace, namespace)) + return true; + } + + return false; +} + +static void add_namespace(struct list_head *head, const char *namespace) +{ + struct namespace_list *ns_entry; + + if (!contains_namespace(head, namespace)) { + ns_entry = NOFAIL(malloc(sizeof(*ns_entry) + + strlen(namespace) + 1)); + strcpy(ns_entry->namespace, namespace); + list_add_tail(&ns_entry->list, head); + } +} + +static void *sym_get_data_by_offset(const struct elf_info *info, + unsigned int secindex, unsigned long offset) +{ + Elf_Shdr *sechdr = &info->sechdrs[secindex]; + + return (void *)info->hdr + sechdr->sh_offset + offset; +} + +void *sym_get_data(const struct elf_info *info, const Elf_Sym *sym) +{ + return sym_get_data_by_offset(info, get_secindex(info, sym), + sym->st_value); +} + +static const char *sech_name(const struct elf_info *info, Elf_Shdr *sechdr) +{ + return sym_get_data_by_offset(info, info->secindex_strings, + sechdr->sh_name); +} + +static const char *sec_name(const struct elf_info *info, unsigned int secindex) +{ + /* + * If sym->st_shndx is a special section index, there is no + * corresponding section header. + * Return "" if the index is out of range of info->sechdrs[] array. + */ + if (secindex >= info->num_sections) + return ""; + + return sech_name(info, &info->sechdrs[secindex]); +} + +#define strstarts(str, prefix) (strncmp(str, prefix, strlen(prefix)) == 0) + +static void sym_update_namespace(const char *symname, const char *namespace) +{ + struct symbol *s = find_symbol(symname); + + /* + * That symbol should have been created earlier and thus this is + * actually an assertion. + */ + if (!s) { + error("Could not update namespace(%s) for symbol %s\n", + namespace, symname); + return; + } + + free(s->namespace); + s->namespace = namespace[0] ? NOFAIL(strdup(namespace)) : NULL; +} + +static struct symbol *sym_add_exported(const char *name, struct module *mod, + bool gpl_only) +{ + struct symbol *s = find_symbol(name); + + if (s && (!external_module || s->module->is_vmlinux || s->module == mod)) { + error("%s: '%s' exported twice. Previous export was in %s%s\n", + mod->name, name, s->module->name, + s->module->is_vmlinux ? "" : ".ko"); + } + + s = alloc_symbol(name); + s->module = mod; + s->is_gpl_only = gpl_only; + list_add_tail(&s->list, &mod->exported_symbols); + hash_add_symbol(s); + + return s; +} + +static void sym_set_crc(struct symbol *sym, unsigned int crc) +{ + sym->crc = crc; + sym->crc_valid = true; +} + +static void *grab_file(const char *filename, size_t *size) +{ + struct stat st; + void *map = MAP_FAILED; + int fd; + + fd = open(filename, O_RDONLY); + if (fd < 0) + return NULL; + if (fstat(fd, &st)) + goto failed; + + *size = st.st_size; + map = mmap(NULL, *size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0); + +failed: + close(fd); + if (map == MAP_FAILED) + return NULL; + return map; +} + +static void release_file(void *file, size_t size) +{ + munmap(file, size); +} + +static int parse_elf(struct elf_info *info, const char *filename) +{ + unsigned int i; + Elf_Ehdr *hdr; + Elf_Shdr *sechdrs; + Elf_Sym *sym; + const char *secstrings; + unsigned int symtab_idx = ~0U, symtab_shndx_idx = ~0U; + + hdr = grab_file(filename, &info->size); + if (!hdr) { + if (ignore_missing_files) { + fprintf(stderr, "%s: %s (ignored)\n", filename, + strerror(errno)); + return 0; + } + perror(filename); + exit(1); + } + info->hdr = hdr; + if (info->size < sizeof(*hdr)) { + /* file too small, assume this is an empty .o file */ + return 0; + } + /* Is this a valid ELF file? */ + if ((hdr->e_ident[EI_MAG0] != ELFMAG0) || + (hdr->e_ident[EI_MAG1] != ELFMAG1) || + (hdr->e_ident[EI_MAG2] != ELFMAG2) || + (hdr->e_ident[EI_MAG3] != ELFMAG3)) { + /* Not an ELF file - silently ignore it */ + return 0; + } + /* Fix endianness in ELF header */ + hdr->e_type = TO_NATIVE(hdr->e_type); + hdr->e_machine = TO_NATIVE(hdr->e_machine); + hdr->e_version = TO_NATIVE(hdr->e_version); + hdr->e_entry = TO_NATIVE(hdr->e_entry); + hdr->e_phoff = TO_NATIVE(hdr->e_phoff); + hdr->e_shoff = TO_NATIVE(hdr->e_shoff); + hdr->e_flags = TO_NATIVE(hdr->e_flags); + hdr->e_ehsize = TO_NATIVE(hdr->e_ehsize); + hdr->e_phentsize = TO_NATIVE(hdr->e_phentsize); + hdr->e_phnum = TO_NATIVE(hdr->e_phnum); + hdr->e_shentsize = TO_NATIVE(hdr->e_shentsize); + hdr->e_shnum = TO_NATIVE(hdr->e_shnum); + hdr->e_shstrndx = TO_NATIVE(hdr->e_shstrndx); + sechdrs = (void *)hdr + hdr->e_shoff; + info->sechdrs = sechdrs; + + /* modpost only works for relocatable objects */ + if (hdr->e_type != ET_REL) + fatal("%s: not relocatable object.", filename); + + /* Check if file offset is correct */ + if (hdr->e_shoff > info->size) { + fatal("section header offset=%lu in file '%s' is bigger than filesize=%zu\n", + (unsigned long)hdr->e_shoff, filename, info->size); + return 0; + } + + if (hdr->e_shnum == SHN_UNDEF) { + /* + * There are more than 64k sections, + * read count from .sh_size. + */ + info->num_sections = TO_NATIVE(sechdrs[0].sh_size); + } + else { + info->num_sections = hdr->e_shnum; + } + if (hdr->e_shstrndx == SHN_XINDEX) { + info->secindex_strings = TO_NATIVE(sechdrs[0].sh_link); + } + else { + info->secindex_strings = hdr->e_shstrndx; + } + + /* Fix endianness in section headers */ + for (i = 0; i < info->num_sections; i++) { + sechdrs[i].sh_name = TO_NATIVE(sechdrs[i].sh_name); + sechdrs[i].sh_type = TO_NATIVE(sechdrs[i].sh_type); + sechdrs[i].sh_flags = TO_NATIVE(sechdrs[i].sh_flags); + sechdrs[i].sh_addr = TO_NATIVE(sechdrs[i].sh_addr); + sechdrs[i].sh_offset = TO_NATIVE(sechdrs[i].sh_offset); + sechdrs[i].sh_size = TO_NATIVE(sechdrs[i].sh_size); + sechdrs[i].sh_link = TO_NATIVE(sechdrs[i].sh_link); + sechdrs[i].sh_info = TO_NATIVE(sechdrs[i].sh_info); + sechdrs[i].sh_addralign = TO_NATIVE(sechdrs[i].sh_addralign); + sechdrs[i].sh_entsize = TO_NATIVE(sechdrs[i].sh_entsize); + } + /* Find symbol table. */ + secstrings = (void *)hdr + sechdrs[info->secindex_strings].sh_offset; + for (i = 1; i < info->num_sections; i++) { + const char *secname; + int nobits = sechdrs[i].sh_type == SHT_NOBITS; + + if (!nobits && sechdrs[i].sh_offset > info->size) { + fatal("%s is truncated. sechdrs[i].sh_offset=%lu > " + "sizeof(*hrd)=%zu\n", filename, + (unsigned long)sechdrs[i].sh_offset, + sizeof(*hdr)); + return 0; + } + secname = secstrings + sechdrs[i].sh_name; + if (strcmp(secname, ".modinfo") == 0) { + if (nobits) + fatal("%s has NOBITS .modinfo\n", filename); + info->modinfo = (void *)hdr + sechdrs[i].sh_offset; + info->modinfo_len = sechdrs[i].sh_size; + } + + if (sechdrs[i].sh_type == SHT_SYMTAB) { + unsigned int sh_link_idx; + symtab_idx = i; + info->symtab_start = (void *)hdr + + sechdrs[i].sh_offset; + info->symtab_stop = (void *)hdr + + sechdrs[i].sh_offset + sechdrs[i].sh_size; + sh_link_idx = sechdrs[i].sh_link; + info->strtab = (void *)hdr + + sechdrs[sh_link_idx].sh_offset; + } + + /* 32bit section no. table? ("more than 64k sections") */ + if (sechdrs[i].sh_type == SHT_SYMTAB_SHNDX) { + symtab_shndx_idx = i; + info->symtab_shndx_start = (void *)hdr + + sechdrs[i].sh_offset; + info->symtab_shndx_stop = (void *)hdr + + sechdrs[i].sh_offset + sechdrs[i].sh_size; + } + } + if (!info->symtab_start) + fatal("%s has no symtab?\n", filename); + + /* Fix endianness in symbols */ + for (sym = info->symtab_start; sym < info->symtab_stop; sym++) { + sym->st_shndx = TO_NATIVE(sym->st_shndx); + sym->st_name = TO_NATIVE(sym->st_name); + sym->st_value = TO_NATIVE(sym->st_value); + sym->st_size = TO_NATIVE(sym->st_size); + } + + if (symtab_shndx_idx != ~0U) { + Elf32_Word *p; + if (symtab_idx != sechdrs[symtab_shndx_idx].sh_link) + fatal("%s: SYMTAB_SHNDX has bad sh_link: %u!=%u\n", + filename, sechdrs[symtab_shndx_idx].sh_link, + symtab_idx); + /* Fix endianness */ + for (p = info->symtab_shndx_start; p < info->symtab_shndx_stop; + p++) + *p = TO_NATIVE(*p); + } + + return 1; +} + +static void parse_elf_finish(struct elf_info *info) +{ + release_file(info->hdr, info->size); +} + +static int ignore_undef_symbol(struct elf_info *info, const char *symname) +{ + /* ignore __this_module, it will be resolved shortly */ + if (strcmp(symname, "__this_module") == 0) + return 1; + /* ignore global offset table */ + if (strcmp(symname, "_GLOBAL_OFFSET_TABLE_") == 0) + return 1; + if (info->hdr->e_machine == EM_PPC) + /* Special register function linked on all modules during final link of .ko */ + if (strstarts(symname, "_restgpr_") || + strstarts(symname, "_savegpr_") || + strstarts(symname, "_rest32gpr_") || + strstarts(symname, "_save32gpr_") || + strstarts(symname, "_restvr_") || + strstarts(symname, "_savevr_")) + return 1; + if (info->hdr->e_machine == EM_PPC64) + /* Special register function linked on all modules during final link of .ko */ + if (strstarts(symname, "_restgpr0_") || + strstarts(symname, "_savegpr0_") || + strstarts(symname, "_restvr_") || + strstarts(symname, "_savevr_") || + strcmp(symname, ".TOC.") == 0) + return 1; + + if (info->hdr->e_machine == EM_S390) + /* Expoline thunks are linked on all kernel modules during final link of .ko */ + if (strstarts(symname, "__s390_indirect_jump_r")) + return 1; + /* Do not ignore this symbol */ + return 0; +} + +static void handle_symbol(struct module *mod, struct elf_info *info, + const Elf_Sym *sym, const char *symname) +{ + switch (sym->st_shndx) { + case SHN_COMMON: + if (strstarts(symname, "__gnu_lto_")) { + /* Should warn here, but modpost runs before the linker */ + } else + warn("\"%s\" [%s] is COMMON symbol\n", symname, mod->name); + break; + case SHN_UNDEF: + /* undefined symbol */ + if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL && + ELF_ST_BIND(sym->st_info) != STB_WEAK) + break; + if (ignore_undef_symbol(info, symname)) + break; + if (info->hdr->e_machine == EM_SPARC || + info->hdr->e_machine == EM_SPARCV9) { + /* Ignore register directives. */ + if (ELF_ST_TYPE(sym->st_info) == STT_SPARC_REGISTER) + break; + if (symname[0] == '.') { + char *munged = NOFAIL(strdup(symname)); + munged[0] = '_'; + munged[1] = toupper(munged[1]); + symname = munged; + } + } + + sym_add_unresolved(symname, mod, + ELF_ST_BIND(sym->st_info) == STB_WEAK); + break; + default: + /* All exported symbols */ + if (strstarts(symname, "__ksymtab_")) { + const char *name, *secname; + + name = symname + strlen("__ksymtab_"); + secname = sec_name(info, get_secindex(info, sym)); + + if (strstarts(secname, "___ksymtab_gpl+")) + sym_add_exported(name, mod, true); + else if (strstarts(secname, "___ksymtab+")) + sym_add_exported(name, mod, false); + } + if (strcmp(symname, "init_module") == 0) + mod->has_init = true; + if (strcmp(symname, "cleanup_module") == 0) + mod->has_cleanup = true; + break; + } +} + +/** + * Parse tag=value strings from .modinfo section + **/ +static char *next_string(char *string, unsigned long *secsize) +{ + /* Skip non-zero chars */ + while (string[0]) { + string++; + if ((*secsize)-- <= 1) + return NULL; + } + + /* Skip any zero padding. */ + while (!string[0]) { + string++; + if ((*secsize)-- <= 1) + return NULL; + } + return string; +} + +static char *get_next_modinfo(struct elf_info *info, const char *tag, + char *prev) +{ + char *p; + unsigned int taglen = strlen(tag); + char *modinfo = info->modinfo; + unsigned long size = info->modinfo_len; + + if (prev) { + size -= prev - modinfo; + modinfo = next_string(prev, &size); + } + + for (p = modinfo; p; p = next_string(p, &size)) { + if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=') + return p + taglen + 1; + } + return NULL; +} + +static char *get_modinfo(struct elf_info *info, const char *tag) + +{ + return get_next_modinfo(info, tag, NULL); +} + +static const char *sym_name(struct elf_info *elf, Elf_Sym *sym) +{ + if (sym) + return elf->strtab + sym->st_name; + else + return "(unknown)"; +} + +/* + * Check whether the 'string' argument matches one of the 'patterns', + * an array of shell wildcard patterns (glob). + * + * Return true is there is a match. + */ +static bool match(const char *string, const char *const patterns[]) +{ + const char *pattern; + + while ((pattern = *patterns++)) { + if (!fnmatch(pattern, string, 0)) + return true; + } + + return false; +} + +/* useful to pass patterns to match() directly */ +#define PATTERNS(...) \ + ({ \ + static const char *const patterns[] = {__VA_ARGS__, NULL}; \ + patterns; \ + }) + +/* sections that we do not want to do full section mismatch check on */ +static const char *const section_white_list[] = +{ + ".comment*", + ".debug*", + ".zdebug*", /* Compressed debug sections. */ + ".GCC.command.line", /* record-gcc-switches */ + ".mdebug*", /* alpha, score, mips etc. */ + ".pdr", /* alpha, score, mips etc. */ + ".stab*", + ".note*", + ".got*", + ".toc*", + ".xt.prop", /* xtensa */ + ".xt.lit", /* xtensa */ + ".arcextmap*", /* arc */ + ".gnu.linkonce.arcext*", /* arc : modules */ + ".cmem*", /* EZchip */ + ".fmt_slot*", /* EZchip */ + ".gnu.lto*", + ".discard.*", + NULL +}; + +/* + * This is used to find sections missing the SHF_ALLOC flag. + * The cause of this is often a section specified in assembler + * without "ax" / "aw". + */ +static void check_section(const char *modname, struct elf_info *elf, + Elf_Shdr *sechdr) +{ + const char *sec = sech_name(elf, sechdr); + + if (sechdr->sh_type == SHT_PROGBITS && + !(sechdr->sh_flags & SHF_ALLOC) && + !match(sec, section_white_list)) { + warn("%s (%s): unexpected non-allocatable section.\n" + "Did you forget to use \"ax\"/\"aw\" in a .S file?\n" + "Note that for example <linux/init.h> contains\n" + "section definitions for use in .S files.\n\n", + modname, sec); + } +} + + + +#define ALL_INIT_DATA_SECTIONS \ + ".init.setup", ".init.rodata", ".meminit.rodata", \ + ".init.data", ".meminit.data" +#define ALL_EXIT_DATA_SECTIONS \ + ".exit.data", ".memexit.data" + +#define ALL_INIT_TEXT_SECTIONS \ + ".init.text", ".meminit.text" +#define ALL_EXIT_TEXT_SECTIONS \ + ".exit.text", ".memexit.text" + +#define ALL_PCI_INIT_SECTIONS \ + ".pci_fixup_early", ".pci_fixup_header", ".pci_fixup_final", \ + ".pci_fixup_enable", ".pci_fixup_resume", \ + ".pci_fixup_resume_early", ".pci_fixup_suspend" + +#define ALL_XXXINIT_SECTIONS MEM_INIT_SECTIONS +#define ALL_XXXEXIT_SECTIONS MEM_EXIT_SECTIONS + +#define ALL_INIT_SECTIONS INIT_SECTIONS, ALL_XXXINIT_SECTIONS +#define ALL_EXIT_SECTIONS EXIT_SECTIONS, ALL_XXXEXIT_SECTIONS + +#define DATA_SECTIONS ".data", ".data.rel" +#define TEXT_SECTIONS ".text", ".text.unlikely", ".sched.text", \ + ".kprobes.text", ".cpuidle.text", ".noinstr.text" +#define OTHER_TEXT_SECTIONS ".ref.text", ".head.text", ".spinlock.text", \ + ".fixup", ".entry.text", ".exception.text", ".text.*", \ + ".coldtext", ".softirqentry.text" + +#define INIT_SECTIONS ".init.*" +#define MEM_INIT_SECTIONS ".meminit.*" + +#define EXIT_SECTIONS ".exit.*" +#define MEM_EXIT_SECTIONS ".memexit.*" + +#define ALL_TEXT_SECTIONS ALL_INIT_TEXT_SECTIONS, ALL_EXIT_TEXT_SECTIONS, \ + TEXT_SECTIONS, OTHER_TEXT_SECTIONS + +/* init data sections */ +static const char *const init_data_sections[] = + { ALL_INIT_DATA_SECTIONS, NULL }; + +/* all init sections */ +static const char *const init_sections[] = { ALL_INIT_SECTIONS, NULL }; + +/* all text sections */ +static const char *const text_sections[] = { ALL_TEXT_SECTIONS, NULL }; + +/* data section */ +static const char *const data_sections[] = { DATA_SECTIONS, NULL }; + +static const char *const head_sections[] = { ".head.text*", NULL }; +static const char *const linker_symbols[] = + { "__init_begin", "_sinittext", "_einittext", NULL }; +static const char *const optim_symbols[] = { "*.constprop.*", NULL }; + +enum mismatch { + TEXT_TO_ANY_INIT, + DATA_TO_ANY_INIT, + TEXT_TO_ANY_EXIT, + DATA_TO_ANY_EXIT, + XXXINIT_TO_SOME_INIT, + XXXEXIT_TO_SOME_EXIT, + ANY_INIT_TO_ANY_EXIT, + ANY_EXIT_TO_ANY_INIT, + EXPORT_TO_INIT_EXIT, + EXTABLE_TO_NON_TEXT, +}; + +/** + * Describe how to match sections on different criteria: + * + * @fromsec: Array of sections to be matched. + * + * @bad_tosec: Relocations applied to a section in @fromsec to a section in + * this array is forbidden (black-list). Can be empty. + * + * @good_tosec: Relocations applied to a section in @fromsec must be + * targeting sections in this array (white-list). Can be empty. + * + * @mismatch: Type of mismatch. + * + * @handler: Specific handler to call when a match is found. If NULL, + * default_mismatch_handler() will be called. + * + */ +struct sectioncheck { + const char *fromsec[20]; + const char *bad_tosec[20]; + const char *good_tosec[20]; + enum mismatch mismatch; + void (*handler)(const char *modname, struct elf_info *elf, + const struct sectioncheck* const mismatch, + Elf_Rela *r, Elf_Sym *sym, const char *fromsec); + +}; + +static void extable_mismatch_handler(const char *modname, struct elf_info *elf, + const struct sectioncheck* const mismatch, + Elf_Rela *r, Elf_Sym *sym, + const char *fromsec); + +static const struct sectioncheck sectioncheck[] = { +/* Do not reference init/exit code/data from + * normal code and data + */ +{ + .fromsec = { TEXT_SECTIONS, NULL }, + .bad_tosec = { ALL_INIT_SECTIONS, NULL }, + .mismatch = TEXT_TO_ANY_INIT, +}, +{ + .fromsec = { DATA_SECTIONS, NULL }, + .bad_tosec = { ALL_XXXINIT_SECTIONS, NULL }, + .mismatch = DATA_TO_ANY_INIT, +}, +{ + .fromsec = { DATA_SECTIONS, NULL }, + .bad_tosec = { INIT_SECTIONS, NULL }, + .mismatch = DATA_TO_ANY_INIT, +}, +{ + .fromsec = { TEXT_SECTIONS, NULL }, + .bad_tosec = { ALL_EXIT_SECTIONS, NULL }, + .mismatch = TEXT_TO_ANY_EXIT, +}, +{ + .fromsec = { DATA_SECTIONS, NULL }, + .bad_tosec = { ALL_EXIT_SECTIONS, NULL }, + .mismatch = DATA_TO_ANY_EXIT, +}, +/* Do not reference init code/data from meminit code/data */ +{ + .fromsec = { ALL_XXXINIT_SECTIONS, NULL }, + .bad_tosec = { INIT_SECTIONS, NULL }, + .mismatch = XXXINIT_TO_SOME_INIT, +}, +/* Do not reference exit code/data from memexit code/data */ +{ + .fromsec = { ALL_XXXEXIT_SECTIONS, NULL }, + .bad_tosec = { EXIT_SECTIONS, NULL }, + .mismatch = XXXEXIT_TO_SOME_EXIT, +}, +/* Do not use exit code/data from init code */ +{ + .fromsec = { ALL_INIT_SECTIONS, NULL }, + .bad_tosec = { ALL_EXIT_SECTIONS, NULL }, + .mismatch = ANY_INIT_TO_ANY_EXIT, +}, +/* Do not use init code/data from exit code */ +{ + .fromsec = { ALL_EXIT_SECTIONS, NULL }, + .bad_tosec = { ALL_INIT_SECTIONS, NULL }, + .mismatch = ANY_EXIT_TO_ANY_INIT, +}, +{ + .fromsec = { ALL_PCI_INIT_SECTIONS, NULL }, + .bad_tosec = { INIT_SECTIONS, NULL }, + .mismatch = ANY_INIT_TO_ANY_EXIT, +}, +/* Do not export init/exit functions or data */ +{ + .fromsec = { "___ksymtab*", NULL }, + .bad_tosec = { INIT_SECTIONS, EXIT_SECTIONS, NULL }, + .mismatch = EXPORT_TO_INIT_EXIT, +}, +{ + .fromsec = { "__ex_table", NULL }, + /* If you're adding any new black-listed sections in here, consider + * adding a special 'printer' for them in scripts/check_extable. + */ + .bad_tosec = { ".altinstr_replacement", NULL }, + .good_tosec = {ALL_TEXT_SECTIONS , NULL}, + .mismatch = EXTABLE_TO_NON_TEXT, + .handler = extable_mismatch_handler, +} +}; + +static const struct sectioncheck *section_mismatch( + const char *fromsec, const char *tosec) +{ + int i; + + /* + * The target section could be the SHT_NUL section when we're + * handling relocations to un-resolved symbols, trying to match it + * doesn't make much sense and causes build failures on parisc + * architectures. + */ + if (*tosec == '\0') + return NULL; + + for (i = 0; i < ARRAY_SIZE(sectioncheck); i++) { + const struct sectioncheck *check = §ioncheck[i]; + + if (match(fromsec, check->fromsec)) { + if (check->bad_tosec[0] && match(tosec, check->bad_tosec)) + return check; + if (check->good_tosec[0] && !match(tosec, check->good_tosec)) + return check; + } + } + return NULL; +} + +/** + * Whitelist to allow certain references to pass with no warning. + * + * Pattern 1: + * If a module parameter is declared __initdata and permissions=0 + * then this is legal despite the warning generated. + * We cannot see value of permissions here, so just ignore + * this pattern. + * The pattern is identified by: + * tosec = .init.data + * fromsec = .data* + * atsym =__param* + * + * Pattern 1a: + * module_param_call() ops can refer to __init set function if permissions=0 + * The pattern is identified by: + * tosec = .init.text + * fromsec = .data* + * atsym = __param_ops_* + * + * Pattern 3: + * Whitelist all references from .head.text to any init section + * + * Pattern 4: + * Some symbols belong to init section but still it is ok to reference + * these from non-init sections as these symbols don't have any memory + * allocated for them and symbol address and value are same. So even + * if init section is freed, its ok to reference those symbols. + * For ex. symbols marking the init section boundaries. + * This pattern is identified by + * refsymname = __init_begin, _sinittext, _einittext + * + * Pattern 5: + * GCC may optimize static inlines when fed constant arg(s) resulting + * in functions like cpumask_empty() -- generating an associated symbol + * cpumask_empty.constprop.3 that appears in the audit. If the const that + * is passed in comes from __init, like say nmi_ipi_mask, we get a + * meaningless section warning. May need to add isra symbols too... + * This pattern is identified by + * tosec = init section + * fromsec = text section + * refsymname = *.constprop.* + * + * Pattern 6: + * Hide section mismatch warnings for ELF local symbols. The goal + * is to eliminate false positive modpost warnings caused by + * compiler-generated ELF local symbol names such as ".LANCHOR1". + * Autogenerated symbol names bypass modpost's "Pattern 2" + * whitelisting, which relies on pattern-matching against symbol + * names to work. (One situation where gcc can autogenerate ELF + * local symbols is when "-fsection-anchors" is used.) + **/ +static int secref_whitelist(const struct sectioncheck *mismatch, + const char *fromsec, const char *fromsym, + const char *tosec, const char *tosym) +{ + /* Check for pattern 1 */ + if (match(tosec, init_data_sections) && + match(fromsec, data_sections) && + strstarts(fromsym, "__param")) + return 0; + + /* Check for pattern 1a */ + if (strcmp(tosec, ".init.text") == 0 && + match(fromsec, data_sections) && + strstarts(fromsym, "__param_ops_")) + return 0; + + /* symbols in data sections that may refer to any init/exit sections */ + if (match(fromsec, PATTERNS(DATA_SECTIONS)) && + match(tosec, PATTERNS(ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS)) && + match(fromsym, PATTERNS("*_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"))) + return 0; + + /* symbols in data sections that may refer to meminit/exit sections */ + if (match(fromsec, PATTERNS(DATA_SECTIONS)) && + match(tosec, PATTERNS(ALL_XXXINIT_SECTIONS, ALL_EXIT_SECTIONS)) && + match(fromsym, PATTERNS("*driver"))) + return 0; + + /* Check for pattern 3 */ + if (match(fromsec, head_sections) && + match(tosec, init_sections)) + return 0; + + /* Check for pattern 4 */ + if (match(tosym, linker_symbols)) + return 0; + + /* Check for pattern 5 */ + if (match(fromsec, text_sections) && + match(tosec, init_sections) && + match(fromsym, optim_symbols)) + return 0; + + /* Check for pattern 6 */ + if (strstarts(fromsym, ".L")) + return 0; + + return 1; +} + +static inline int is_arm_mapping_symbol(const char *str) +{ + return str[0] == '$' && + (str[1] == 'a' || str[1] == 'd' || str[1] == 't' || str[1] == 'x') + && (str[2] == '\0' || str[2] == '.'); +} + +/* + * If there's no name there, ignore it; likewise, ignore it if it's + * one of the magic symbols emitted used by current ARM tools. + * + * Otherwise if find_symbols_between() returns those symbols, they'll + * fail the whitelist tests and cause lots of false alarms ... fixable + * only by merging __exit and __init sections into __text, bloating + * the kernel (which is especially evil on embedded platforms). + */ +static inline int is_valid_name(struct elf_info *elf, Elf_Sym *sym) +{ + const char *name = elf->strtab + sym->st_name; + + if (!name || !strlen(name)) + return 0; + return !is_arm_mapping_symbol(name); +} + +/** + * Find symbol based on relocation record info. + * In some cases the symbol supplied is a valid symbol so + * return refsym. If st_name != 0 we assume this is a valid symbol. + * In other cases the symbol needs to be looked up in the symbol table + * based on section and address. + * **/ +static Elf_Sym *find_elf_symbol(struct elf_info *elf, Elf64_Sword addr, + Elf_Sym *relsym) +{ + Elf_Sym *sym; + Elf_Sym *near = NULL; + Elf64_Sword distance = 20; + Elf64_Sword d; + unsigned int relsym_secindex; + + if (relsym->st_name != 0) + return relsym; + + /* + * Strive to find a better symbol name, but the resulting name may not + * match the symbol referenced in the original code. + */ + relsym_secindex = get_secindex(elf, relsym); + for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) { + if (get_secindex(elf, sym) != relsym_secindex) + continue; + if (ELF_ST_TYPE(sym->st_info) == STT_SECTION) + continue; + if (!is_valid_name(elf, sym)) + continue; + if (sym->st_value == addr) + return sym; + /* Find a symbol nearby - addr are maybe negative */ + d = sym->st_value - addr; + if (d < 0) + d = addr - sym->st_value; + if (d < distance) { + distance = d; + near = sym; + } + } + /* We need a close match */ + if (distance < 20) + return near; + else + return NULL; +} + +/* + * Find symbols before or equal addr and after addr - in the section sec. + * If we find two symbols with equal offset prefer one with a valid name. + * The ELF format may have a better way to detect what type of symbol + * it is, but this works for now. + **/ +static Elf_Sym *find_elf_symbol2(struct elf_info *elf, Elf_Addr addr, + const char *sec) +{ + Elf_Sym *sym; + Elf_Sym *near = NULL; + Elf_Addr distance = ~0; + + for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) { + const char *symsec; + + if (is_shndx_special(sym->st_shndx)) + continue; + symsec = sec_name(elf, get_secindex(elf, sym)); + if (strcmp(symsec, sec) != 0) + continue; + if (!is_valid_name(elf, sym)) + continue; + if (sym->st_value <= addr && addr - sym->st_value <= distance) { + distance = addr - sym->st_value; + near = sym; + } + } + return near; +} + +static int is_function(Elf_Sym *sym) +{ + if (sym) + return ELF_ST_TYPE(sym->st_info) == STT_FUNC; + else + return -1; +} + +static inline void get_pretty_name(int is_func, const char** name, const char** name_p) +{ + switch (is_func) { + case 0: *name = "variable"; *name_p = ""; break; + case 1: *name = "function"; *name_p = "()"; break; + default: *name = "(unknown reference)"; *name_p = ""; break; + } +} + +/* + * Print a warning about a section mismatch. + * Try to find symbols near it so user can find it. + * Check whitelist before warning - it may be a false positive. + */ +static void report_sec_mismatch(const char *modname, + const struct sectioncheck *mismatch, + const char *fromsec, + const char *fromsym, + const char *tosec, const char *tosym) +{ + sec_mismatch_count++; + + switch (mismatch->mismatch) { + case TEXT_TO_ANY_INIT: + case DATA_TO_ANY_INIT: + case TEXT_TO_ANY_EXIT: + case DATA_TO_ANY_EXIT: + case XXXINIT_TO_SOME_INIT: + case XXXEXIT_TO_SOME_EXIT: + case ANY_INIT_TO_ANY_EXIT: + case ANY_EXIT_TO_ANY_INIT: + warn("%s: section mismatch in reference: %s (section: %s) -> %s (section: %s)\n", + modname, fromsym, fromsec, tosym, tosec); + break; + case EXPORT_TO_INIT_EXIT: + warn("%s: EXPORT_SYMBOL used for init/exit symbol: %s (section: %s)\n", + modname, tosym, tosec); + break; + case EXTABLE_TO_NON_TEXT: + fatal("There's a special handler for this mismatch type, we should never get here.\n"); + break; + } +} + +static void default_mismatch_handler(const char *modname, struct elf_info *elf, + const struct sectioncheck* const mismatch, + Elf_Rela *r, Elf_Sym *sym, const char *fromsec) +{ + const char *tosec; + Elf_Sym *to; + Elf_Sym *from; + const char *tosym; + const char *fromsym; + + from = find_elf_symbol2(elf, r->r_offset, fromsec); + fromsym = sym_name(elf, from); + + tosec = sec_name(elf, get_secindex(elf, sym)); + to = find_elf_symbol(elf, r->r_addend, sym); + tosym = sym_name(elf, to); + + /* check whitelist - we may ignore it */ + if (secref_whitelist(mismatch, + fromsec, fromsym, tosec, tosym)) { + report_sec_mismatch(modname, mismatch, + fromsec, fromsym, tosec, tosym); + } +} + +static int is_executable_section(struct elf_info* elf, unsigned int section_index) +{ + if (section_index >= elf->num_sections) + fatal("section_index is outside elf->num_sections!\n"); + + return ((elf->sechdrs[section_index].sh_flags & SHF_EXECINSTR) == SHF_EXECINSTR); +} + +static void report_extable_warnings(const char* modname, struct elf_info* elf, + const struct sectioncheck* const mismatch, + Elf_Rela* r, Elf_Sym* sym, + const char* fromsec, const char* tosec) +{ + Elf_Sym* fromsym = find_elf_symbol2(elf, r->r_offset, fromsec); + const char* fromsym_name = sym_name(elf, fromsym); + Elf_Sym* tosym = find_elf_symbol(elf, r->r_addend, sym); + const char* tosym_name = sym_name(elf, tosym); + const char* from_pretty_name; + const char* from_pretty_name_p; + const char* to_pretty_name; + const char* to_pretty_name_p; + + get_pretty_name(is_function(fromsym), + &from_pretty_name, &from_pretty_name_p); + get_pretty_name(is_function(tosym), + &to_pretty_name, &to_pretty_name_p); + + warn("%s(%s+0x%lx): Section mismatch in reference" + " from the %s %s%s to the %s %s:%s%s\n", + modname, fromsec, (long)r->r_offset, from_pretty_name, + fromsym_name, from_pretty_name_p, + to_pretty_name, tosec, tosym_name, to_pretty_name_p); + + if (!match(tosec, mismatch->bad_tosec) && + is_executable_section(elf, get_secindex(elf, sym))) + fprintf(stderr, + "The relocation at %s+0x%lx references\n" + "section \"%s\" which is not in the list of\n" + "authorized sections. If you're adding a new section\n" + "and/or if this reference is valid, add \"%s\" to the\n" + "list of authorized sections to jump to on fault.\n" + "This can be achieved by adding \"%s\" to \n" + "OTHER_TEXT_SECTIONS in scripts/mod/modpost.c.\n", + fromsec, (long)r->r_offset, tosec, tosec, tosec); +} + +static void extable_mismatch_handler(const char* modname, struct elf_info *elf, + const struct sectioncheck* const mismatch, + Elf_Rela* r, Elf_Sym* sym, + const char *fromsec) +{ + const char* tosec = sec_name(elf, get_secindex(elf, sym)); + + sec_mismatch_count++; + + report_extable_warnings(modname, elf, mismatch, r, sym, fromsec, tosec); + + if (match(tosec, mismatch->bad_tosec)) + fatal("The relocation at %s+0x%lx references\n" + "section \"%s\" which is black-listed.\n" + "Something is seriously wrong and should be fixed.\n" + "You might get more information about where this is\n" + "coming from by using scripts/check_extable.sh %s\n", + fromsec, (long)r->r_offset, tosec, modname); + else if (!is_executable_section(elf, get_secindex(elf, sym))) + error("%s+0x%lx references non-executable section '%s'\n", + fromsec, (long)r->r_offset, tosec); +} + +static void check_section_mismatch(const char *modname, struct elf_info *elf, + Elf_Rela *r, Elf_Sym *sym, const char *fromsec) +{ + const char *tosec = sec_name(elf, get_secindex(elf, sym)); + const struct sectioncheck *mismatch = section_mismatch(fromsec, tosec); + + if (mismatch) { + if (mismatch->handler) + mismatch->handler(modname, elf, mismatch, + r, sym, fromsec); + else + default_mismatch_handler(modname, elf, mismatch, + r, sym, fromsec); + } +} + +static unsigned int *reloc_location(struct elf_info *elf, + Elf_Shdr *sechdr, Elf_Rela *r) +{ + return sym_get_data_by_offset(elf, sechdr->sh_info, r->r_offset); +} + +static int addend_386_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r) +{ + unsigned int r_typ = ELF_R_TYPE(r->r_info); + unsigned int *location = reloc_location(elf, sechdr, r); + + switch (r_typ) { + case R_386_32: + r->r_addend = TO_NATIVE(*location); + break; + case R_386_PC32: + r->r_addend = TO_NATIVE(*location) + 4; + break; + } + return 0; +} + +#ifndef R_ARM_CALL +#define R_ARM_CALL 28 +#endif +#ifndef R_ARM_JUMP24 +#define R_ARM_JUMP24 29 +#endif + +#ifndef R_ARM_THM_CALL +#define R_ARM_THM_CALL 10 +#endif +#ifndef R_ARM_THM_JUMP24 +#define R_ARM_THM_JUMP24 30 +#endif +#ifndef R_ARM_THM_JUMP19 +#define R_ARM_THM_JUMP19 51 +#endif + +static int32_t sign_extend32(int32_t value, int index) +{ + uint8_t shift = 31 - index; + + return (int32_t)(value << shift) >> shift; +} + +static int addend_arm_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r) +{ + unsigned int r_typ = ELF_R_TYPE(r->r_info); + Elf_Sym *sym = elf->symtab_start + ELF_R_SYM(r->r_info); + void *loc = reloc_location(elf, sechdr, r); + uint32_t inst; + int32_t offset; + + switch (r_typ) { + case R_ARM_ABS32: + inst = TO_NATIVE(*(uint32_t *)loc); + r->r_addend = inst + sym->st_value; + break; + case R_ARM_PC24: + case R_ARM_CALL: + case R_ARM_JUMP24: + inst = TO_NATIVE(*(uint32_t *)loc); + offset = sign_extend32((inst & 0x00ffffff) << 2, 25); + r->r_addend = offset + sym->st_value + 8; + break; + case R_ARM_THM_CALL: + case R_ARM_THM_JUMP24: + case R_ARM_THM_JUMP19: + /* From ARM ABI: ((S + A) | T) - P */ + r->r_addend = (int)(long)(elf->hdr + + sechdr->sh_offset + + (r->r_offset - sechdr->sh_addr)); + break; + default: + return 1; + } + return 0; +} + +static int addend_mips_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r) +{ + unsigned int r_typ = ELF_R_TYPE(r->r_info); + unsigned int *location = reloc_location(elf, sechdr, r); + unsigned int inst; + + if (r_typ == R_MIPS_HI16) + return 1; /* skip this */ + inst = TO_NATIVE(*location); + switch (r_typ) { + case R_MIPS_LO16: + r->r_addend = inst & 0xffff; + break; + case R_MIPS_26: + r->r_addend = (inst & 0x03ffffff) << 2; + break; + case R_MIPS_32: + r->r_addend = inst; + break; + } + return 0; +} + +#ifndef EM_RISCV +#define EM_RISCV 243 +#endif + +#ifndef R_RISCV_SUB32 +#define R_RISCV_SUB32 39 +#endif + +static void section_rela(const char *modname, struct elf_info *elf, + Elf_Shdr *sechdr) +{ + Elf_Sym *sym; + Elf_Rela *rela; + Elf_Rela r; + unsigned int r_sym; + const char *fromsec; + + Elf_Rela *start = (void *)elf->hdr + sechdr->sh_offset; + Elf_Rela *stop = (void *)start + sechdr->sh_size; + + fromsec = sec_name(elf, sechdr->sh_info); + /* if from section (name) is know good then skip it */ + if (match(fromsec, section_white_list)) + return; + + for (rela = start; rela < stop; rela++) { + r.r_offset = TO_NATIVE(rela->r_offset); +#if KERNEL_ELFCLASS == ELFCLASS64 + if (elf->hdr->e_machine == EM_MIPS) { + unsigned int r_typ; + r_sym = ELF64_MIPS_R_SYM(rela->r_info); + r_sym = TO_NATIVE(r_sym); + r_typ = ELF64_MIPS_R_TYPE(rela->r_info); + r.r_info = ELF64_R_INFO(r_sym, r_typ); + } else { + r.r_info = TO_NATIVE(rela->r_info); + r_sym = ELF_R_SYM(r.r_info); + } +#else + r.r_info = TO_NATIVE(rela->r_info); + r_sym = ELF_R_SYM(r.r_info); +#endif + r.r_addend = TO_NATIVE(rela->r_addend); + switch (elf->hdr->e_machine) { + case EM_RISCV: + if (!strcmp("__ex_table", fromsec) && + ELF_R_TYPE(r.r_info) == R_RISCV_SUB32) + continue; + break; + } + sym = elf->symtab_start + r_sym; + /* Skip special sections */ + if (is_shndx_special(sym->st_shndx)) + continue; + 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 = sec_name(elf, sechdr->sh_info); + /* 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(const char *modname, struct elf_info *elf) +{ + int i; + Elf_Shdr *sechdrs = elf->sechdrs; + + /* Walk through all sections */ + for (i = 0; i < elf->num_sections; i++) { + check_section(modname, elf, &elf->sechdrs[i]); + /* We want to process only relocation sections and not .init */ + if (sechdrs[i].sh_type == SHT_RELA) + section_rela(modname, elf, &elf->sechdrs[i]); + else if (sechdrs[i].sh_type == SHT_REL) + section_rel(modname, elf, &elf->sechdrs[i]); + } +} + +static char *remove_dot(char *s) +{ + size_t n = strcspn(s, "."); + + if (n && s[n]) { + size_t m = strspn(s + n + 1, "0123456789"); + if (m && (s[n + m + 1] == '.' || s[n + m + 1] == 0)) + s[n] = 0; + } + return s; +} + +/* + * The CRCs are recorded in .*.cmd files in the form of: + * #SYMVER <name> <crc> + */ +static void extract_crcs_for_object(const char *object, struct module *mod) +{ + char cmd_file[PATH_MAX]; + char *buf, *p; + const char *base; + int dirlen, ret; + + base = strrchr(object, '/'); + if (base) { + base++; + dirlen = base - object; + } else { + dirlen = 0; + base = object; + } + + ret = snprintf(cmd_file, sizeof(cmd_file), "%.*s.%s.cmd", + dirlen, object, base); + if (ret >= sizeof(cmd_file)) { + error("%s: too long path was truncated\n", cmd_file); + return; + } + + buf = read_text_file(cmd_file); + p = buf; + + while ((p = strstr(p, "\n#SYMVER "))) { + char *name; + size_t namelen; + unsigned int crc; + struct symbol *sym; + + name = p + strlen("\n#SYMVER "); + + p = strchr(name, ' '); + if (!p) + break; + + namelen = p - name; + p++; + + if (!isdigit(*p)) + continue; /* skip this line */ + + crc = strtoul(p, &p, 0); + if (*p != '\n') + continue; /* skip this line */ + + name[namelen] = '\0'; + + /* + * sym_find_with_module() may return NULL here. + * It typically occurs when CONFIG_TRIM_UNUSED_KSYMS=y. + * Since commit e1327a127703, genksyms calculates CRCs of all + * symbols, including trimmed ones. Ignore orphan CRCs. + */ + sym = sym_find_with_module(name, mod); + if (sym) + sym_set_crc(sym, crc); + } + + free(buf); +} + +/* + * The symbol versions (CRC) are recorded in the .*.cmd files. + * Parse them to retrieve CRCs for the current module. + */ +static void mod_set_crcs(struct module *mod) +{ + char objlist[PATH_MAX]; + char *buf, *p, *obj; + int ret; + + if (mod->is_vmlinux) { + strcpy(objlist, ".vmlinux.objs"); + } else { + /* objects for a module are listed in the *.mod file. */ + ret = snprintf(objlist, sizeof(objlist), "%s.mod", mod->name); + if (ret >= sizeof(objlist)) { + error("%s: too long path was truncated\n", objlist); + return; + } + } + + buf = read_text_file(objlist); + p = buf; + + while ((obj = strsep(&p, "\n")) && obj[0]) + extract_crcs_for_object(obj, mod); + + free(buf); +} + +static void read_symbols(const char *modname) +{ + const char *symname; + char *version; + char *license; + char *namespace; + struct module *mod; + struct elf_info info = { }; + Elf_Sym *sym; + + if (!parse_elf(&info, modname)) + return; + + if (!strends(modname, ".o")) { + error("%s: filename must be suffixed with .o\n", modname); + return; + } + + /* strip trailing .o */ + mod = new_module(modname, strlen(modname) - strlen(".o")); + + if (!mod->is_vmlinux) { + license = get_modinfo(&info, "license"); + if (!license) + error("missing MODULE_LICENSE() in %s\n", modname); + while (license) { + if (!license_is_gpl_compatible(license)) { + mod->is_gpl_compatible = false; + break; + } + license = get_next_modinfo(&info, "license", license); + } + + namespace = get_modinfo(&info, "import_ns"); + while (namespace) { + add_namespace(&mod->imported_namespaces, namespace); + namespace = get_next_modinfo(&info, "import_ns", + namespace); + } + } + + for (sym = info.symtab_start; sym < info.symtab_stop; sym++) { + symname = remove_dot(info.strtab + sym->st_name); + + handle_symbol(mod, &info, sym, symname); + handle_moddevtable(mod, &info, sym, symname); + } + + for (sym = info.symtab_start; sym < info.symtab_stop; sym++) { + symname = remove_dot(info.strtab + sym->st_name); + + /* Apply symbol namespaces from __kstrtabns_<symbol> entries. */ + if (strstarts(symname, "__kstrtabns_")) + sym_update_namespace(symname + strlen("__kstrtabns_"), + sym_get_data(&info, sym)); + } + + check_sec_ref(modname, &info); + + if (!mod->is_vmlinux) { + version = get_modinfo(&info, "version"); + if (version || all_versions) + get_src_version(mod->name, mod->srcversion, + sizeof(mod->srcversion) - 1); + } + + parse_elf_finish(&info); + + if (modversions) { + /* + * Our trick to get versioning for module struct etc. - it's + * never passed as an argument to an exported function, so + * the automatic versioning doesn't pick it up, but it's really + * important anyhow. + */ + sym_add_unresolved("module_layout", mod, false); + + mod_set_crcs(mod); + } +} + +static void read_symbols_from_files(const char *filename) +{ + FILE *in = stdin; + char fname[PATH_MAX]; + + if (strcmp(filename, "-") != 0) { + in = fopen(filename, "r"); + if (!in) + fatal("Can't open filenames file %s: %m", filename); + } + + while (fgets(fname, PATH_MAX, in) != NULL) { + if (strends(fname, "\n")) + fname[strlen(fname)-1] = '\0'; + read_symbols(fname); + } + + if (in != stdin) + fclose(in); +} + +#define SZ 500 + +/* We first write the generated file into memory using the + * following helper, then compare to the file on disk and + * only update the later if anything changed */ + +void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf, + const char *fmt, ...) +{ + char tmp[SZ]; + int len; + va_list ap; + + va_start(ap, fmt); + len = vsnprintf(tmp, SZ, fmt, ap); + buf_write(buf, tmp, len); + va_end(ap); +} + +void buf_write(struct buffer *buf, const char *s, int len) +{ + if (buf->size - buf->pos < len) { + buf->size += len + SZ; + buf->p = NOFAIL(realloc(buf->p, buf->size)); + } + strncpy(buf->p + buf->pos, s, len); + buf->pos += len; +} + +static void check_exports(struct module *mod) +{ + struct symbol *s, *exp; + + list_for_each_entry(s, &mod->unresolved_symbols, list) { + const char *basename; + exp = find_symbol(s->name); + if (!exp) { + if (!s->weak && nr_unresolved++ < MAX_UNRESOLVED_REPORTS) + modpost_log(warn_unresolved ? LOG_WARN : LOG_ERROR, + "\"%s\" [%s.ko] undefined!\n", + s->name, mod->name); + continue; + } + if (exp->module == mod) { + error("\"%s\" [%s.ko] was exported without definition\n", + s->name, mod->name); + continue; + } + + s->module = exp->module; + s->crc_valid = exp->crc_valid; + s->crc = exp->crc; + + basename = strrchr(mod->name, '/'); + if (basename) + basename++; + else + basename = mod->name; + + if (exp->namespace && + !contains_namespace(&mod->imported_namespaces, exp->namespace)) { + modpost_log(allow_missing_ns_imports ? LOG_WARN : LOG_ERROR, + "module %s uses symbol %s from namespace %s, but does not import it.\n", + basename, exp->name, exp->namespace); + add_namespace(&mod->missing_namespaces, exp->namespace); + } + + if (!mod->is_gpl_compatible && exp->is_gpl_only) + error("GPL-incompatible module %s.ko uses GPL-only symbol '%s'\n", + basename, exp->name); + } +} + +static void check_modname_len(struct module *mod) +{ + const char *mod_name; + + mod_name = strrchr(mod->name, '/'); + if (mod_name == NULL) + mod_name = mod->name; + else + mod_name++; + if (strlen(mod_name) >= MODULE_NAME_LEN) + error("module name is too long [%s.ko]\n", mod->name); +} + +/** + * Header for the generated file + **/ +static void add_header(struct buffer *b, struct module *mod) +{ + buf_printf(b, "#include <linux/module.h>\n"); + /* + * Include build-salt.h after module.h in order to + * inherit the definitions. + */ + buf_printf(b, "#define INCLUDE_VERMAGIC\n"); + buf_printf(b, "#include <linux/build-salt.h>\n"); + buf_printf(b, "#include <linux/elfnote-lto.h>\n"); + buf_printf(b, "#include <linux/export-internal.h>\n"); + buf_printf(b, "#include <linux/vermagic.h>\n"); + buf_printf(b, "#include <linux/compiler.h>\n"); + buf_printf(b, "\n"); + buf_printf(b, "BUILD_SALT;\n"); + buf_printf(b, "BUILD_LTO_INFO;\n"); + buf_printf(b, "\n"); + buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n"); + buf_printf(b, "MODULE_INFO(name, KBUILD_MODNAME);\n"); + buf_printf(b, "\n"); + buf_printf(b, "__visible struct module __this_module\n"); + buf_printf(b, "__section(\".gnu.linkonce.this_module\") = {\n"); + buf_printf(b, "\t.name = KBUILD_MODNAME,\n"); + if (mod->has_init) + buf_printf(b, "\t.init = init_module,\n"); + if (mod->has_cleanup) + buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n" + "\t.exit = cleanup_module,\n" + "#endif\n"); + buf_printf(b, "\t.arch = MODULE_ARCH_INIT,\n"); + buf_printf(b, "};\n"); + + if (!external_module) + buf_printf(b, "\nMODULE_INFO(intree, \"Y\");\n"); + + buf_printf(b, + "\n" + "#ifdef CONFIG_RETPOLINE\n" + "MODULE_INFO(retpoline, \"Y\");\n" + "#endif\n"); + + if (strstarts(mod->name, "drivers/staging")) + buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n"); + + if (strstarts(mod->name, "tools/testing")) + buf_printf(b, "\nMODULE_INFO(test, \"Y\");\n"); +} + +static void add_exported_symbols(struct buffer *buf, struct module *mod) +{ + struct symbol *sym; + + if (!modversions) + return; + + /* record CRCs for exported symbols */ + buf_printf(buf, "\n"); + list_for_each_entry(sym, &mod->exported_symbols, list) { + if (!sym->crc_valid) + warn("EXPORT symbol \"%s\" [%s%s] version generation failed, symbol will not be versioned.\n" + "Is \"%s\" prototyped in <asm/asm-prototypes.h>?\n", + sym->name, mod->name, mod->is_vmlinux ? "" : ".ko", + sym->name); + + buf_printf(buf, "SYMBOL_CRC(%s, 0x%08x, \"%s\");\n", + sym->name, sym->crc, sym->is_gpl_only ? "_gpl" : ""); + } +} + +/** + * Record CRCs for unresolved symbols + **/ +static void add_versions(struct buffer *b, struct module *mod) +{ + struct symbol *s; + + if (!modversions) + return; + + buf_printf(b, "\n"); + buf_printf(b, "static const struct modversion_info ____versions[]\n"); + buf_printf(b, "__used __section(\"__versions\") = {\n"); + + list_for_each_entry(s, &mod->unresolved_symbols, list) { + if (!s->module) + continue; + if (!s->crc_valid) { + warn("\"%s\" [%s.ko] has no CRC!\n", + s->name, mod->name); + continue; + } + if (strlen(s->name) >= MODULE_NAME_LEN) { + error("too long symbol \"%s\" [%s.ko]\n", + s->name, mod->name); + break; + } + buf_printf(b, "\t{ %#8x, \"%s\" },\n", + s->crc, s->name); + } + + buf_printf(b, "};\n"); +} + +static void add_depends(struct buffer *b, struct module *mod) +{ + struct symbol *s; + int first = 1; + + /* Clear ->seen flag of modules that own symbols needed by this. */ + list_for_each_entry(s, &mod->unresolved_symbols, list) { + if (s->module) + s->module->seen = s->module->is_vmlinux; + } + + buf_printf(b, "\n"); + buf_printf(b, "MODULE_INFO(depends, \""); + list_for_each_entry(s, &mod->unresolved_symbols, list) { + const char *p; + if (!s->module) + continue; + + if (s->module->seen) + continue; + + s->module->seen = true; + p = strrchr(s->module->name, '/'); + if (p) + p++; + else + p = s->module->name; + buf_printf(b, "%s%s", first ? "" : ",", p); + first = 0; + } + buf_printf(b, "\");\n"); +} + +static void add_srcversion(struct buffer *b, struct module *mod) +{ + if (mod->srcversion[0]) { + buf_printf(b, "\n"); + buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n", + mod->srcversion); + } +} + +static void write_buf(struct buffer *b, const char *fname) +{ + FILE *file; + + if (error_occurred) + return; + + file = fopen(fname, "w"); + if (!file) { + perror(fname); + exit(1); + } + if (fwrite(b->p, 1, b->pos, file) != b->pos) { + perror(fname); + exit(1); + } + if (fclose(file) != 0) { + perror(fname); + exit(1); + } +} + +static void write_if_changed(struct buffer *b, const char *fname) +{ + char *tmp; + FILE *file; + struct stat st; + + file = fopen(fname, "r"); + if (!file) + goto write; + + if (fstat(fileno(file), &st) < 0) + goto close_write; + + if (st.st_size != b->pos) + goto close_write; + + tmp = NOFAIL(malloc(b->pos)); + if (fread(tmp, 1, b->pos, file) != b->pos) + goto free_write; + + if (memcmp(tmp, b->p, b->pos) != 0) + goto free_write; + + free(tmp); + fclose(file); + return; + + free_write: + free(tmp); + close_write: + fclose(file); + write: + write_buf(b, fname); +} + +static void write_vmlinux_export_c_file(struct module *mod) +{ + struct buffer buf = { }; + + buf_printf(&buf, + "#include <linux/export-internal.h>\n"); + + add_exported_symbols(&buf, mod); + write_if_changed(&buf, ".vmlinux.export.c"); + free(buf.p); +} + +/* do sanity checks, and generate *.mod.c file */ +static void write_mod_c_file(struct module *mod) +{ + struct buffer buf = { }; + char fname[PATH_MAX]; + int ret; + + check_modname_len(mod); + check_exports(mod); + + add_header(&buf, mod); + add_exported_symbols(&buf, mod); + add_versions(&buf, mod); + add_depends(&buf, mod); + add_moddevtable(&buf, mod); + add_srcversion(&buf, mod); + + ret = snprintf(fname, sizeof(fname), "%s.mod.c", mod->name); + if (ret >= sizeof(fname)) { + error("%s: too long path was truncated\n", fname); + goto free; + } + + write_if_changed(&buf, fname); + +free: + free(buf.p); +} + +/* parse Module.symvers file. line format: + * 0x12345678<tab>symbol<tab>module<tab>export<tab>namespace + **/ +static void read_dump(const char *fname) +{ + char *buf, *pos, *line; + + buf = read_text_file(fname); + if (!buf) + /* No symbol versions, silently ignore */ + return; + + pos = buf; + + while ((line = get_line(&pos))) { + char *symname, *namespace, *modname, *d, *export; + unsigned int crc; + struct module *mod; + struct symbol *s; + bool gpl_only; + + if (!(symname = strchr(line, '\t'))) + goto fail; + *symname++ = '\0'; + if (!(modname = strchr(symname, '\t'))) + goto fail; + *modname++ = '\0'; + if (!(export = strchr(modname, '\t'))) + goto fail; + *export++ = '\0'; + if (!(namespace = strchr(export, '\t'))) + goto fail; + *namespace++ = '\0'; + + crc = strtoul(line, &d, 16); + if (*symname == '\0' || *modname == '\0' || *d != '\0') + goto fail; + + if (!strcmp(export, "EXPORT_SYMBOL_GPL")) { + gpl_only = true; + } else if (!strcmp(export, "EXPORT_SYMBOL")) { + gpl_only = false; + } else { + error("%s: unknown license %s. skip", symname, export); + continue; + } + + mod = find_module(modname); + if (!mod) { + mod = new_module(modname, strlen(modname)); + mod->from_dump = true; + } + s = sym_add_exported(symname, mod, gpl_only); + sym_set_crc(s, crc); + sym_update_namespace(symname, namespace); + } + free(buf); + return; +fail: + free(buf); + fatal("parse error in symbol dump file\n"); +} + +static void write_dump(const char *fname) +{ + struct buffer buf = { }; + struct module *mod; + struct symbol *sym; + + list_for_each_entry(mod, &modules, list) { + if (mod->from_dump) + continue; + list_for_each_entry(sym, &mod->exported_symbols, list) { + buf_printf(&buf, "0x%08x\t%s\t%s\tEXPORT_SYMBOL%s\t%s\n", + sym->crc, sym->name, mod->name, + sym->is_gpl_only ? "_GPL" : "", + sym->namespace ?: ""); + } + } + write_buf(&buf, fname); + free(buf.p); +} + +static void write_namespace_deps_files(const char *fname) +{ + struct module *mod; + struct namespace_list *ns; + struct buffer ns_deps_buf = {}; + + list_for_each_entry(mod, &modules, list) { + + if (mod->from_dump || list_empty(&mod->missing_namespaces)) + continue; + + buf_printf(&ns_deps_buf, "%s.ko:", mod->name); + + list_for_each_entry(ns, &mod->missing_namespaces, list) + buf_printf(&ns_deps_buf, " %s", ns->namespace); + + buf_printf(&ns_deps_buf, "\n"); + } + + write_if_changed(&ns_deps_buf, fname); + free(ns_deps_buf.p); +} + +struct dump_list { + struct list_head list; + const char *file; +}; + +int main(int argc, char **argv) +{ + struct module *mod; + char *missing_namespace_deps = NULL; + char *dump_write = NULL, *files_source = NULL; + int opt; + LIST_HEAD(dump_lists); + struct dump_list *dl, *dl2; + + while ((opt = getopt(argc, argv, "ei:mnT:o:awENd:")) != -1) { + switch (opt) { + case 'e': + external_module = true; + break; + case 'i': + dl = NOFAIL(malloc(sizeof(*dl))); + dl->file = optarg; + list_add_tail(&dl->list, &dump_lists); + break; + case 'm': + modversions = true; + break; + case 'n': + ignore_missing_files = true; + break; + case 'o': + dump_write = optarg; + break; + case 'a': + all_versions = true; + break; + case 'T': + files_source = optarg; + break; + case 'w': + warn_unresolved = true; + break; + case 'E': + sec_mismatch_warn_only = false; + break; + case 'N': + allow_missing_ns_imports = true; + break; + case 'd': + missing_namespace_deps = optarg; + break; + default: + exit(1); + } + } + + list_for_each_entry_safe(dl, dl2, &dump_lists, list) { + read_dump(dl->file); + list_del(&dl->list); + free(dl); + } + + while (optind < argc) + read_symbols(argv[optind++]); + + if (files_source) + read_symbols_from_files(files_source); + + list_for_each_entry(mod, &modules, list) { + if (mod->from_dump) + continue; + + if (mod->is_vmlinux) + write_vmlinux_export_c_file(mod); + else + write_mod_c_file(mod); + } + + if (missing_namespace_deps) + write_namespace_deps_files(missing_namespace_deps); + + if (dump_write) + write_dump(dump_write); + if (sec_mismatch_count && !sec_mismatch_warn_only) + error("Section mismatches detected.\n" + "Set CONFIG_SECTION_MISMATCH_WARN_ONLY=y to allow them.\n"); + + if (nr_unresolved > MAX_UNRESOLVED_REPORTS) + warn("suppressed %u unresolved symbol warnings because there were too many)\n", + nr_unresolved - MAX_UNRESOLVED_REPORTS); + + return error_occurred ? 1 : 0; +} |