modpost: remove the unused argument of check_sec_ref()
[linux-2.6-microblaze.git] / scripts / mod / modpost.c
index ed9d056..2806a5c 100644 (file)
 #include "../../include/linux/license.h"
 
 /* Are we using CONFIG_MODVERSIONS? */
-static int modversions = 0;
+static bool modversions;
 /* Is CONFIG_MODULE_SRCVERSION_ALL set? */
-static int all_versions = 0;
+static bool all_versions;
 /* If we are modposting external module set to 1 */
-static int external_module = 0;
+static bool external_module;
 /* 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_warn_only = true;
+static bool warn_unresolved;
+
+static int sec_mismatch_count;
+static bool sec_mismatch_warn_only = true;
 /* ignore missing files */
-static int ignore_missing_files;
+static bool ignore_missing_files;
 /* If set to 1, only warn (instead of error) about missing ns imports */
-static int allow_missing_ns_imports;
+static bool allow_missing_ns_imports;
 
 static bool error_occurred;
 
@@ -47,12 +47,6 @@ static bool error_occurred;
 #define MAX_UNRESOLVED_REPORTS 10
 static unsigned int nr_unresolved;
 
-enum export {
-       export_plain,
-       export_gpl,
-       export_unknown
-};
-
 /* In kernel, this size is defined in linux/module.h;
  * here we use Elf_Addr instead of long for covering cross-compile
  */
@@ -165,16 +159,17 @@ char *get_line(char **stringp)
 }
 
 /* A list of all modules we processed */
-static struct module *modules;
+LIST_HEAD(modules);
 
 static struct module *find_module(const char *modname)
 {
        struct module *mod;
 
-       for (mod = modules; mod; mod = mod->next)
+       list_for_each_entry(mod, &modules, list) {
                if (strcmp(mod->name, modname) == 0)
-                       break;
-       return mod;
+                       return mod;
+       }
+       return NULL;
 }
 
 static struct module *new_module(const char *modname)
@@ -184,12 +179,22 @@ static struct module *new_module(const char *modname)
        mod = NOFAIL(malloc(sizeof(*mod) + strlen(modname) + 1));
        memset(mod, 0, sizeof(*mod));
 
-       /* add to list */
+       INIT_LIST_HEAD(&mod->exported_symbols);
+       INIT_LIST_HEAD(&mod->unresolved_symbols);
+       INIT_LIST_HEAD(&mod->missing_namespaces);
+       INIT_LIST_HEAD(&mod->imported_namespaces);
+
        strcpy(mod->name, modname);
        mod->is_vmlinux = (strcmp(modname, "vmlinux") == 0);
-       mod->gpl_compatible = -1;
-       mod->next = modules;
-       modules = mod;
+
+       /*
+        * 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;
 }
@@ -201,13 +206,14 @@ static struct module *new_module(const char *modname)
 
 struct symbol {
        struct symbol *next;
+       struct list_head list;  /* link to module::exported_symbols or module::unresolved_symbols */
        struct module *module;
-       unsigned int crc;
-       int crc_valid;
        char *namespace;
-       unsigned int weak:1;
-       unsigned int is_static:1;  /* 1 if symbol is not global */
-       enum export  export;       /* Type of export */
+       unsigned int crc;
+       bool crc_valid;
+       bool weak;
+       bool is_static;         /* true if symbol is not global */
+       bool is_gpl_only;       /* exported by EXPORT_SYMBOL_GPL */
        char name[];
 };
 
@@ -230,32 +236,37 @@ static inline unsigned int tdb_hash(const char *name)
  * 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)
+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);
-       s->weak = weak;
-       s->next = next;
-       s->is_static = 1;
+       s->is_static = true;
        return s;
 }
 
 /* For the hash of exported symbols */
-static struct symbol *new_symbol(const char *name, struct module *module,
-                                enum export export)
+static void hash_add_symbol(struct symbol *sym)
 {
        unsigned int hash;
 
-       hash = tdb_hash(name) % SYMBOL_HASH_SIZE;
-       symbolhash[hash] = alloc_symbol(name, 0, symbolhash[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;
 
-       return symbolhash[hash];
+       sym = alloc_symbol(name);
+       sym->weak = weak;
+
+       list_add_tail(&sym->list, &mod->unresolved_symbols);
 }
 
-static struct symbol *find_symbol(const char *name)
+static struct symbol *sym_find_with_module(const char *name, struct module *mod)
 {
        struct symbol *s;
 
@@ -264,67 +275,44 @@ static struct symbol *find_symbol(const char *name)
                name++;
 
        for (s = symbolhash[tdb_hash(name) % SYMBOL_HASH_SIZE]; s; s = s->next) {
-               if (strcmp(s->name, name) == 0)
+               if (strcmp(s->name, name) == 0 && (!mod || s->module == mod))
                        return s;
        }
        return NULL;
 }
 
-static bool contains_namespace(struct namespace_list *list,
-                              const char *namespace)
+static struct symbol *find_symbol(const char *name)
 {
-       for (; list; list = list->next)
+       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 namespace_list **list, const char *namespace)
+static void add_namespace(struct list_head *head, const char *namespace)
 {
        struct namespace_list *ns_entry;
 
-       if (!contains_namespace(*list, namespace)) {
-               ns_entry = NOFAIL(malloc(sizeof(struct namespace_list) +
+       if (!contains_namespace(head, namespace)) {
+               ns_entry = NOFAIL(malloc(sizeof(*ns_entry) +
                                         strlen(namespace) + 1));
                strcpy(ns_entry->namespace, namespace);
-               ns_entry->next = *list;
-               *list = ns_entry;
-       }
-}
-
-static bool module_imports_namespace(struct module *module,
-                                    const char *namespace)
-{
-       return contains_namespace(module->imported_namespaces, namespace);
-}
-
-static const struct {
-       const char *str;
-       enum export export;
-} export_list[] = {
-       { .str = "EXPORT_SYMBOL",            .export = export_plain },
-       { .str = "EXPORT_SYMBOL_GPL",        .export = export_gpl },
-       { .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;
+               list_add_tail(&ns_entry->list, head);
        }
-       return export_unknown;
 }
 
 static void *sym_get_data_by_offset(const struct elf_info *info,
@@ -357,35 +345,6 @@ static const char *sec_name(const struct elf_info *info, 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_gpl+"))
-               return export_gpl;
-       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_gpl_sec)
-               return export_gpl;
-       else
-               return export_unknown;
-}
-
-static const char *namespace_from_kstrtabns(const struct elf_info *info,
-                                           const Elf_Sym *sym)
-{
-       const char *value = sym_get_data(info, sym);
-       return value[0] ? value : NULL;
-}
-
 static void sym_update_namespace(const char *symname, const char *namespace)
 {
        struct symbol *s = find_symbol(symname);
@@ -401,47 +360,33 @@ static void sym_update_namespace(const char *symname, const char *namespace)
        }
 
        free(s->namespace);
-       s->namespace =
-               namespace && namespace[0] ? NOFAIL(strdup(namespace)) : NULL;
+       s->namespace = namespace[0] ? NOFAIL(strdup(namespace)) : NULL;
 }
 
-/**
- * Add an exported symbol - it may have already been added without a
- * CRC, in this case just update the CRC
- **/
 static struct symbol *sym_add_exported(const char *name, struct module *mod,
-                                      enum export export)
+                                      bool gpl_only)
 {
        struct symbol *s = find_symbol(name);
 
-       if (!s) {
-               s = new_symbol(name, mod, export);
-       } else if (!external_module || s->module->is_vmlinux ||
-                  s->module == mod) {
-               warn("%s: '%s' exported twice. Previous export was in %s%s\n",
-                    mod->name, name, s->module->name,
-                    s->module->is_vmlinux ? "" : ".ko");
-               return s;
+       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->export    = export;
+       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(const char *name, unsigned int crc)
+static void sym_set_crc(struct symbol *sym, unsigned int crc)
 {
-       struct symbol *s = find_symbol(name);
-
-       /*
-        * Ignore stand-alone __crc_*, which might be auto-generated symbols
-        * such as __*_veneer in ARM ELF.
-        */
-       if (!s)
-               return;
-
-       s->crc = crc;
-       s->crc_valid = 1;
+       sym->crc = crc;
+       sym->crc_valid = true;
 }
 
 static void *grab_file(const char *filename, size_t *size)
@@ -576,10 +521,7 @@ static int parse_elf(struct elf_info *info, const char *filename)
                                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_gpl") == 0)
-                       info->export_gpl_sec = i;
+               }
 
                if (sechdrs[i].sh_type == SHT_SYMTAB) {
                        unsigned int sh_link_idx;
@@ -667,44 +609,9 @@ static int ignore_undef_symbol(struct elf_info *info, const char *symname)
        return 0;
 }
 
-static void handle_modversion(const struct module *mod,
-                             const struct elf_info *info,
-                             const Elf_Sym *sym, const char *symname)
-{
-       unsigned int crc;
-
-       if (sym->st_shndx == SHN_UNDEF) {
-               warn("EXPORT symbol \"%s\" [%s%s] version generation failed, symbol will not be versioned.\n"
-                    "Is \"%s\" prototyped in <asm/asm-prototypes.h>?\n",
-                    symname, mod->name, mod->is_vmlinux ? "" : ".ko",
-                    symname);
-
-               return;
-       }
-
-       if (sym->st_shndx == SHN_ABS) {
-               crc = sym->st_value;
-       } else {
-               unsigned int *crcp;
-
-               /* symbol points to the CRC in the ELF object */
-               crcp = sym_get_data(info, sym);
-               crc = TO_NATIVE(*crcp);
-       }
-       sym_set_crc(symname, crc);
-}
-
 static void handle_symbol(struct module *mod, struct elf_info *info,
                          const Elf_Sym *sym, const char *symname)
 {
-       enum export export;
-       const char *name;
-
-       if (strstarts(symname, "__ksymtab"))
-               export = export_from_secname(info, get_secindex(info, sym));
-       else
-               export = export_from_sec(info, get_secindex(info, sym));
-
        switch (sym->st_shndx) {
        case SHN_COMMON:
                if (strstarts(symname, "__gnu_lto_")) {
@@ -732,20 +639,26 @@ static void handle_symbol(struct module *mod, struct elf_info *info,
                        }
                }
 
-               mod->unres = alloc_symbol(symname,
-                                         ELF_ST_BIND(sym->st_info) == STB_WEAK,
-                                         mod->unres);
+               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_");
-                       sym_add_exported(name, mod, export);
+                       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 = 1;
+                       mod->has_init = true;
                if (strcmp(symname, "cleanup_module") == 0)
-                       mod->has_cleanup = 1;
+                       mod->has_cleanup = true;
                break;
        }
 }
@@ -1267,7 +1180,8 @@ static int secref_whitelist(const struct sectioncheck *mismatch,
 
 static inline int is_arm_mapping_symbol(const char *str)
 {
-       return str[0] == '$' && strchr("axtd", str[1])
+       return str[0] == '$' &&
+              (str[1] == 'a' || str[1] == 'd' || str[1] == 't' || str[1] == 'x')
               && (str[2] == '\0' || str[2] == '.');
 }
 
@@ -1970,8 +1884,7 @@ static void section_rel(const char *modname, struct elf_info *elf,
  * 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)
+static void check_sec_ref(const char *modname, struct elf_info *elf)
 {
        int i;
        Elf_Shdr *sechdrs = elf->sechdrs;
@@ -1993,7 +1906,7 @@ static char *remove_dot(char *s)
 
        if (n && s[n]) {
                size_t m = strspn(s + n + 1, "0123456789");
-               if (m && (s[n + m] == '.' || s[n + m] == 0))
+               if (m && (s[n + m + 1] == '.' || s[n + m + 1] == 0))
                        s[n] = 0;
 
                /* strip trailing .prelink */
@@ -2003,6 +1916,104 @@ static char *remove_dot(char *s)
        return s;
 }
 
+/*
+ * The CRCs are recorded in .*.cmd files in the form of:
+ * #SYMVER <name> <crc>
+ */
+static void extract_crcs_for_object(const char *object, struct module *mod)
+{
+       char cmd_file[PATH_MAX];
+       char *buf, *p;
+       const char *base;
+       int dirlen, ret;
+
+       base = strrchr(object, '/');
+       if (base) {
+               base++;
+               dirlen = base - object;
+       } else {
+               dirlen = 0;
+               base = object;
+       }
+
+       ret = snprintf(cmd_file, sizeof(cmd_file), "%.*s.%s.cmd",
+                      dirlen, object, base);
+       if (ret >= sizeof(cmd_file)) {
+               error("%s: too long path was truncated\n", cmd_file);
+               return;
+       }
+
+       buf = read_text_file(cmd_file);
+       p = buf;
+
+       while ((p = strstr(p, "\n#SYMVER "))) {
+               char *name;
+               size_t namelen;
+               unsigned int crc;
+               struct symbol *sym;
+
+               name = p + strlen("\n#SYMVER ");
+
+               p = strchr(name, ' ');
+               if (!p)
+                       break;
+
+               namelen = p - name;
+               p++;
+
+               if (!isdigit(*p))
+                       continue;       /* skip this line */
+
+               crc = strtol(p, &p, 0);
+               if (*p != '\n')
+                       continue;       /* skip this line */
+
+               name[namelen] = '\0';
+
+               /*
+                * sym_find_with_module() may return NULL here.
+                * It typically occurs when CONFIG_TRIM_UNUSED_KSYMS=y.
+                * Since commit e1327a127703, genksyms calculates CRCs of all
+                * symbols, including trimmed ones. Ignore orphan CRCs.
+                */
+               sym = sym_find_with_module(name, mod);
+               if (sym)
+                       sym_set_crc(sym, crc);
+       }
+
+       free(buf);
+}
+
+/*
+ * The symbol versions (CRC) are recorded in the .*.cmd files.
+ * Parse them to retrieve CRCs for the current module.
+ */
+static void mod_set_crcs(struct module *mod)
+{
+       char objlist[PATH_MAX];
+       char *buf, *p, *obj;
+       int ret;
+
+       if (mod->is_vmlinux) {
+               strcpy(objlist, ".vmlinux.objs");
+       } else {
+               /* objects for a module are listed in the *.mod file. */
+               ret = snprintf(objlist, sizeof(objlist), "%s.mod", mod->name);
+               if (ret >= sizeof(objlist)) {
+                       error("%s: too long path was truncated\n", objlist);
+                       return;
+               }
+       }
+
+       buf = read_text_file(objlist);
+       p = buf;
+
+       while ((obj = strsep(&p, "\n")) && obj[0])
+               extract_crcs_for_object(obj, mod);
+
+       free(buf);
+}
+
 static void read_symbols(const char *modname)
 {
        const char *symname;
@@ -2034,10 +2045,8 @@ static void read_symbols(const char *modname)
                if (!license)
                        error("missing MODULE_LICENSE() in %s\n", modname);
                while (license) {
-                       if (license_is_gpl_compatible(license))
-                               mod->gpl_compatible = 1;
-                       else {
-                               mod->gpl_compatible = 0;
+                       if (!license_is_gpl_compatible(license)) {
+                               mod->is_gpl_compatible = false;
                                break;
                        }
                        license = get_next_modinfo(&info, "license", license);
@@ -2064,12 +2073,7 @@ static void read_symbols(const char *modname)
                /* Apply symbol namespaces from __kstrtabns_<symbol> entries. */
                if (strstarts(symname, "__kstrtabns_"))
                        sym_update_namespace(symname + strlen("__kstrtabns_"),
-                                            namespace_from_kstrtabns(&info,
-                                                                     sym));
-
-               if (strstarts(symname, "__crc_"))
-                       handle_modversion(mod, &info, sym,
-                                         symname + strlen("__crc_"));
+                                            sym_get_data(&info, sym));
        }
 
        // check for static EXPORT_SYMBOL_* functions && global vars
@@ -2082,11 +2086,11 @@ static void read_symbols(const char *modname)
                                                       sym->st_name));
 
                        if (s)
-                               s->is_static = 0;
+                               s->is_static = false;
                }
        }
 
-       check_sec_ref(mod, modname, &info);
+       check_sec_ref(modname, &info);
 
        if (!mod->is_vmlinux) {
                version = get_modinfo(&info, "version");
@@ -2097,12 +2101,17 @@ static void read_symbols(const char *modname)
 
        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);
+       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)
@@ -2155,34 +2164,30 @@ void buf_write(struct buffer *buf, const char *s, int len)
        buf->pos += len;
 }
 
-static void check_for_gpl_usage(enum export exp, const char *m, const char *s)
-{
-       switch (exp) {
-       case export_gpl:
-               error("GPL-incompatible module %s.ko uses GPL-only symbol '%s'\n",
-                     m, s);
-               break;
-       case export_plain:
-       case export_unknown:
-               /* ignore */
-               break;
-       }
-}
-
 static void check_exports(struct module *mod)
 {
        struct symbol *s, *exp;
 
-       for (s = mod->unres; s; s = s->next) {
+       list_for_each_entry(s, &mod->unresolved_symbols, list) {
                const char *basename;
                exp = find_symbol(s->name);
-               if (!exp || exp->module == mod) {
+               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++;
@@ -2190,15 +2195,16 @@ static void check_exports(struct module *mod)
                        basename = mod->name;
 
                if (exp->namespace &&
-                   !module_imports_namespace(mod, 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->gpl_compatible)
-                       check_for_gpl_usage(exp->export, basename, exp->name);
+               if (!mod->is_gpl_compatible && exp->is_gpl_only)
+                       error("GPL-incompatible module %s.ko uses GPL-only symbol '%s'\n",
+                             basename, exp->name);
        }
 }
 
@@ -2228,6 +2234,7 @@ static void add_header(struct buffer *b, struct module *mod)
        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");
@@ -2248,26 +2255,41 @@ static void add_header(struct buffer *b, struct module *mod)
                              "#endif\n");
        buf_printf(b, "\t.arch = MODULE_ARCH_INIT,\n");
        buf_printf(b, "};\n");
-}
 
-static void add_intree_flag(struct buffer *b, int is_intree)
-{
-       if (is_intree)
+       if (!external_module)
                buf_printf(b, "\nMODULE_INFO(intree, \"Y\");\n");
-}
 
-/* Cannot check for assembler */
-static void add_retpoline(struct buffer *b)
-{
-       buf_printf(b, "\n#ifdef CONFIG_RETPOLINE\n");
-       buf_printf(b, "MODULE_INFO(retpoline, \"Y\");\n");
-       buf_printf(b, "#endif\n");
+       buf_printf(b,
+                  "\n"
+                  "#ifdef CONFIG_RETPOLINE\n"
+                  "MODULE_INFO(retpoline, \"Y\");\n"
+                  "#endif\n");
+
+       if (strstarts(mod->name, "drivers/staging"))
+               buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n");
 }
 
-static void add_staging_flag(struct buffer *b, const char *name)
+static void add_exported_symbols(struct buffer *buf, struct module *mod)
 {
-       if (strstarts(name, "drivers/staging"))
-               buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n");
+       struct symbol *sym;
+
+       if (!modversions)
+               return;
+
+       /* record CRCs for exported symbols */
+       buf_printf(buf, "\n");
+       list_for_each_entry(sym, &mod->exported_symbols, list) {
+               if (!sym->crc_valid) {
+                       warn("EXPORT symbol \"%s\" [%s%s] version generation failed, symbol will not be versioned.\n"
+                            "Is \"%s\" prototyped in <asm/asm-prototypes.h>?\n",
+                            sym->name, mod->name, mod->is_vmlinux ? "" : ".ko",
+                            sym->name);
+                       continue;
+               }
+
+               buf_printf(buf, "SYMBOL_CRC(%s, 0x%08x, \"%s\");\n",
+                          sym->name, sym->crc, sym->is_gpl_only ? "_gpl" : "");
+       }
 }
 
 /**
@@ -2275,16 +2297,7 @@ static void add_staging_flag(struct buffer *b, const char *name)
  **/
 static void add_versions(struct buffer *b, struct module *mod)
 {
-       struct symbol *s, *exp;
-
-       for (s = mod->unres; s; s = s->next) {
-               exp = find_symbol(s->name);
-               if (!exp || exp->module == mod)
-                       continue;
-               s->module = exp->module;
-               s->crc_valid = exp->crc_valid;
-               s->crc = exp->crc;
-       }
+       struct symbol *s;
 
        if (!modversions)
                return;
@@ -2293,7 +2306,7 @@ static void add_versions(struct buffer *b, struct module *mod)
        buf_printf(b, "static const struct modversion_info ____versions[]\n");
        buf_printf(b, "__used __section(\"__versions\") = {\n");
 
-       for (s = mod->unres; s; s = s->next) {
+       list_for_each_entry(s, &mod->unresolved_symbols, list) {
                if (!s->module)
                        continue;
                if (!s->crc_valid) {
@@ -2319,13 +2332,14 @@ static void add_depends(struct buffer *b, struct module *mod)
        int first = 1;
 
        /* Clear ->seen flag of modules that own symbols needed by this. */
-       for (s = mod->unres; s; s = s->next)
+       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, \"");
-       for (s = mod->unres; s; s = s->next) {
+       list_for_each_entry(s, &mod->unresolved_symbols, list) {
                const char *p;
                if (!s->module)
                        continue;
@@ -2333,7 +2347,7 @@ static void add_depends(struct buffer *b, struct module *mod)
                if (s->module->seen)
                        continue;
 
-               s->module->seen = 1;
+               s->module->seen = true;
                p = strrchr(s->module->name, '/');
                if (p)
                        p++;
@@ -2358,6 +2372,9 @@ static void write_buf(struct buffer *b, const char *fname)
 {
        FILE *file;
 
+       if (error_occurred)
+               return;
+
        file = fopen(fname, "w");
        if (!file) {
                perror(fname);
@@ -2408,6 +2425,47 @@ static void write_if_changed(struct buffer *b, const char *fname)
        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
  **/
@@ -2427,6 +2485,7 @@ static void read_dump(const char *fname)
                unsigned int crc;
                struct module *mod;
                struct symbol *s;
+               bool gpl_only;
 
                if (!(symname = strchr(line, '\t')))
                        goto fail;
@@ -2444,14 +2503,24 @@ static void read_dump(const char *fname)
                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);
-                       mod->from_dump = 1;
+                       mod->from_dump = true;
                }
-               s = sym_add_exported(symname, mod, export_no(export));
-               s->is_static = 0;
-               sym_set_crc(symname, crc);
+               s = sym_add_exported(symname, mod, gpl_only);
+               s->is_static = false;
+               sym_set_crc(s, crc);
                sym_update_namespace(symname, namespace);
        }
        free(buf);
@@ -2464,22 +2533,17 @@ fail:
 static void write_dump(const char *fname)
 {
        struct buffer buf = { };
-       struct symbol *symbol;
-       const char *namespace;
-       int n;
+       struct module *mod;
+       struct symbol *sym;
 
-       for (n = 0; n < SYMBOL_HASH_SIZE ; n++) {
-               symbol = symbolhash[n];
-               while (symbol) {
-                       if (!symbol->module->from_dump) {
-                               namespace = symbol->namespace;
-                               buf_printf(&buf, "0x%08x\t%s\t%s\t%s\t%s\n",
-                                          symbol->crc, symbol->name,
-                                          symbol->module->name,
-                                          export_str(symbol->export),
-                                          namespace ? namespace : "");
-                       }
-                       symbol = symbol->next;
+       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);
@@ -2492,14 +2556,14 @@ static void write_namespace_deps_files(const char *fname)
        struct namespace_list *ns;
        struct buffer ns_deps_buf = {};
 
-       for (mod = modules; mod; mod = mod->next) {
+       list_for_each_entry(mod, &modules, list) {
 
-               if (mod->from_dump || !mod->missing_namespaces)
+               if (mod->from_dump || list_empty(&mod->missing_namespaces))
                        continue;
 
                buf_printf(&ns_deps_buf, "%s.ko:", mod->name);
 
-               for (ns = mod->missing_namespaces; ns; ns = ns->next)
+               list_for_each_entry(ns, &mod->missing_namespaces, list)
                        buf_printf(&ns_deps_buf, " %s", ns->namespace);
 
                buf_printf(&ns_deps_buf, "\n");
@@ -2510,55 +2574,53 @@ static void write_namespace_deps_files(const char *fname)
 }
 
 struct dump_list {
-       struct dump_list *next;
+       struct list_head list;
        const char *file;
 };
 
 int main(int argc, char **argv)
 {
        struct module *mod;
-       struct buffer buf = { };
        char *missing_namespace_deps = NULL;
        char *dump_write = NULL, *files_source = NULL;
        int opt;
        int n;
-       struct dump_list *dump_read_start = NULL;
-       struct dump_list **dump_read_iter = &dump_read_start;
+       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 = 1;
+                       external_module = true;
                        break;
                case 'i':
-                       *dump_read_iter =
-                               NOFAIL(calloc(1, sizeof(**dump_read_iter)));
-                       (*dump_read_iter)->file = optarg;
-                       dump_read_iter = &(*dump_read_iter)->next;
+                       dl = NOFAIL(malloc(sizeof(*dl)));
+                       dl->file = optarg;
+                       list_add_tail(&dl->list, &dump_lists);
                        break;
                case 'm':
-                       modversions = 1;
+                       modversions = true;
                        break;
                case 'n':
-                       ignore_missing_files = 1;
+                       ignore_missing_files = true;
                        break;
                case 'o':
                        dump_write = optarg;
                        break;
                case 'a':
-                       all_versions = 1;
+                       all_versions = true;
                        break;
                case 'T':
                        files_source = optarg;
                        break;
                case 'w':
-                       warn_unresolved = 1;
+                       warn_unresolved = true;
                        break;
                case 'E':
                        sec_mismatch_warn_only = false;
                        break;
                case 'N':
-                       allow_missing_ns_imports = 1;
+                       allow_missing_ns_imports = true;
                        break;
                case 'd':
                        missing_namespace_deps = optarg;
@@ -2568,13 +2630,10 @@ int main(int argc, char **argv)
                }
        }
 
-       while (dump_read_start) {
-               struct dump_list *tmp;
-
-               read_dump(dump_read_start->file);
-               tmp = dump_read_start->next;
-               free(dump_read_start);
-               dump_read_start = tmp;
+       list_for_each_entry_safe(dl, dl2, &dump_lists, list) {
+               read_dump(dl->file);
+               list_del(&dl->list);
+               free(dl);
        }
 
        while (optind < argc)
@@ -2583,28 +2642,14 @@ int main(int argc, char **argv)
        if (files_source)
                read_symbols_from_files(files_source);
 
-       for (mod = modules; mod; mod = mod->next) {
-               char fname[PATH_MAX];
-
-               if (mod->is_vmlinux || mod->from_dump)
+       list_for_each_entry(mod, &modules, list) {
+               if (mod->from_dump)
                        continue;
 
-               buf.pos = 0;
-
-               check_modname_len(mod);
-               check_exports(mod);
-
-               add_header(&buf, mod);
-               add_intree_flag(&buf, !external_module);
-               add_retpoline(&buf);
-               add_staging_flag(&buf, mod->name);
-               add_versions(&buf, mod);
-               add_depends(&buf, mod);
-               add_moddevtable(&buf, mod);
-               add_srcversion(&buf, mod);
-
-               sprintf(fname, "%s.mod.c", mod->name);
-               write_if_changed(&buf, fname);
+               if (mod->is_vmlinux)
+                       write_vmlinux_export_c_file(mod);
+               else
+                       write_mod_c_file(mod);
        }
 
        if (missing_namespace_deps)
@@ -2620,9 +2665,8 @@ int main(int argc, char **argv)
 
                for (s = symbolhash[n]; s; s = s->next) {
                        if (s->is_static)
-                               error("\"%s\" [%s] is a static %s\n",
-                                     s->name, s->module->name,
-                                     export_str(s->export));
+                               error("\"%s\" [%s] is a static EXPORT_SYMBOL\n",
+                                     s->name, s->module->name);
                }
        }
 
@@ -2630,7 +2674,5 @@ int main(int argc, char **argv)
                warn("suppressed %u unresolved symbol warnings because there were too many)\n",
                     nr_unresolved - MAX_UNRESOLVED_REPORTS);
 
-       free(buf.p);
-
        return error_occurred ? 1 : 0;
 }