--- /dev/null
+/* Postprocess module symbol versions
+ *
+ * Copyright 2003 Kai Germaschewski
+ * 2002-2003 Rusty Russell, IBM Corporation
+ *
+ * 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 ...
+ */
+
+#include <ctype.h>
+#include "modpost.h"
+
+/* Are we using CONFIG_MODVERSIONS? */
+int modversions = 0;
+/* Warn about undefined symbols? (do so if we have vmlinux) */
+int have_vmlinux = 0;
+
+void
+fatal(const char *fmt, ...)
+{
+ va_list arglist;
+
+ fprintf(stderr, "FATAL: ");
+
+ va_start(arglist, fmt);
+ vfprintf(stderr, fmt, arglist);
+ va_end(arglist);
+
+ exit(1);
+}
+
+void
+warn(const char *fmt, ...)
+{
+ va_list arglist;
+
+ fprintf(stderr, "WARNING: ");
+
+ va_start(arglist, fmt);
+ vfprintf(stderr, fmt, arglist);
+ va_end(arglist);
+}
+
+void *do_nofail(void *ptr, const char *file, int line, const char *expr)
+{
+ if (!ptr) {
+ fatal("Memory allocation failure %s line %d: %s.\n",
+ file, line, expr);
+ }
+ return ptr;
+}
+
+/* A list of all modules we processed */
+
+static struct module *modules;
+
+struct module *
+find_module(char *modname)
+{
+ struct module *mod;
+
+ for (mod = modules; mod; mod = mod->next)
+ if (strcmp(mod->name, modname) == 0)
+ break;
+ return mod;
+}
+
+struct module *
+new_module(char *modname)
+{
+ struct module *mod;
+ char *p, *s;
+
+ mod = NOFAIL(malloc(sizeof(*mod)));
+ memset(mod, 0, sizeof(*mod));
+ p = NOFAIL(strdup(modname));
+
+ /* strip trailing .o */
+ if ((s = strrchr(p, '.')) != NULL)
+ if (strcmp(s, ".o") == 0)
+ *s = '\0';
+
+ /* add to list */
+ mod->name = p;
+ mod->next = modules;
+ modules = mod;
+
+ return mod;
+}
+
+/* A hash of all exported symbols,
+ * struct symbol is also used for lists of unresolved symbols */
+
+#define SYMBOL_HASH_SIZE 1024
+
+struct symbol {
+ struct symbol *next;
+ struct module *module;
+ unsigned int crc;
+ int crc_valid;
+ char name[0];
+};
+
+static struct symbol *symbolhash[SYMBOL_HASH_SIZE];
+
+/* This is based on the hash agorithm from gdbm, via tdb */
+static inline unsigned int tdb_hash(const char *name)
+{
+ unsigned value; /* Used to compute the hash value. */
+ unsigned i; /* Used to cycle through random values. */
+
+ /* Set the initial value from the key size. */
+ for (value = 0x238F13AF * strlen(name), i=0; name[i]; i++)
+ value = (value + (((unsigned char *)name)[i] << (i*5 % 24)));
+
+ return (1103515243 * value + 12345);
+}
+
+/* Allocate a new symbols for use in the hash of exported symbols or
+ * the list of unresolved symbols per module */
+
+struct symbol *
+alloc_symbol(const char *name, struct symbol *next)
+{
+ struct symbol *s = NOFAIL(malloc(sizeof(*s) + strlen(name) + 1));
+
+ memset(s, 0, sizeof(*s));
+ strcpy(s->name, name);
+ s->next = next;
+ return s;
+}
+
+/* For the hash of exported symbols */
+
+void
+new_symbol(const char *name, struct module *module, unsigned int *crc)
+{
+ unsigned int hash;
+ struct symbol *new;
+
+ hash = tdb_hash(name) % SYMBOL_HASH_SIZE;
+ new = symbolhash[hash] = alloc_symbol(name, symbolhash[hash]);
+ new->module = module;
+ if (crc) {
+ new->crc = *crc;
+ new->crc_valid = 1;
+ }
+}
+
+struct symbol *
+find_symbol(const char *name)
+{
+ struct symbol *s;
+
+ /* For our purposes, .foo matches foo. PPC64 needs this. */
+ if (name[0] == '.')
+ name++;
+
+ for (s = symbolhash[tdb_hash(name) % SYMBOL_HASH_SIZE]; s; s=s->next) {
+ if (strcmp(s->name, name) == 0)
+ return s;
+ }
+ return NULL;
+}
+
+/* Add an exported symbol - it may have already been added without a
+ * CRC, in this case just update the CRC */
+void
+add_exported_symbol(const char *name, struct module *module, unsigned int *crc)
+{
+ struct symbol *s = find_symbol(name);
+
+ if (!s) {
+ new_symbol(name, module, crc);
+ return;
+ }
+ if (crc) {
+ s->crc = *crc;
+ s->crc_valid = 1;
+ }
+}
+
+void *
+grab_file(const char *filename, unsigned long *size)
+{
+ struct stat st;
+ void *map;
+ int fd;
+
+ fd = open(filename, O_RDONLY);
+ if (fd < 0 || fstat(fd, &st) != 0)
+ return NULL;
+
+ *size = st.st_size;
+ map = mmap(NULL, *size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0);
+ close(fd);
+
+ if (map == MAP_FAILED)
+ return NULL;
+ return map;
+}
+
+/*
+ Return a copy of the next line in a mmap'ed file.
+ spaces in the beginning of the line is trimmed away.
+ Return a pointer to a static buffer.
+*/
+char*
+get_next_line(unsigned long *pos, void *file, unsigned long size)
+{
+ static char line[4096];
+ int skip = 1;
+ size_t len = 0;
+ char *p = (char *)file + *pos;
+ char *s = line;
+
+ for (; *pos < size ; (*pos)++)
+ {
+ if (skip && isspace(*p)) {
+ p++;
+ continue;
+ }
+ skip = 0;
+ if (*p != '\n' && (*pos < size)) {
+ len++;
+ *s++ = *p++;
+ if (len > 4095)
+ break; /* Too long, stop */
+ } else {
+ /* End of string */
+ *s = '\0';
+ return line;
+ }
+ }
+ /* End of buffer */
+ return NULL;
+}
+
+void
+release_file(void *file, unsigned long size)
+{
+ munmap(file, size);
+}
+
+void
+parse_elf(struct elf_info *info, const char *filename)
+{
+ unsigned int i;
+ Elf_Ehdr *hdr = info->hdr;
+ Elf_Shdr *sechdrs;
+ Elf_Sym *sym;
+
+ hdr = grab_file(filename, &info->size);
+ if (!hdr) {
+ perror(filename);
+ abort();
+ }
+ info->hdr = hdr;
+ if (info->size < sizeof(*hdr))
+ goto truncated;
+
+ /* Fix endianness in ELF header */
+ hdr->e_shoff = TO_NATIVE(hdr->e_shoff);
+ hdr->e_shstrndx = TO_NATIVE(hdr->e_shstrndx);
+ hdr->e_shnum = TO_NATIVE(hdr->e_shnum);
+ hdr->e_machine = TO_NATIVE(hdr->e_machine);
+ sechdrs = (void *)hdr + hdr->e_shoff;
+ info->sechdrs = sechdrs;
+
+ /* Fix endianness in section headers */
+ for (i = 0; i < hdr->e_shnum; i++) {
+ sechdrs[i].sh_type = TO_NATIVE(sechdrs[i].sh_type);
+ 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_name = TO_NATIVE(sechdrs[i].sh_name);
+ }
+ /* Find symbol table. */
+ for (i = 1; i < hdr->e_shnum; i++) {
+ const char *secstrings
+ = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
+
+ if (sechdrs[i].sh_offset > info->size)
+ goto truncated;
+ if (strcmp(secstrings+sechdrs[i].sh_name, ".modinfo") == 0) {
+ info->modinfo = (void *)hdr + sechdrs[i].sh_offset;
+ info->modinfo_len = sechdrs[i].sh_size;
+ }
+ if (sechdrs[i].sh_type != SHT_SYMTAB)
+ continue;
+
+ info->symtab_start = (void *)hdr + sechdrs[i].sh_offset;
+ info->symtab_stop = (void *)hdr + sechdrs[i].sh_offset
+ + sechdrs[i].sh_size;
+ info->strtab = (void *)hdr +
+ sechdrs[sechdrs[i].sh_link].sh_offset;
+ }
+ if (!info->symtab_start) {
+ fprintf(stderr, "modpost: %s no symtab?\n", filename);
+ abort();
+ }
+ /* Fix endianness in symbols */
+ for (sym = info->symtab_start; sym < info->symtab_stop; sym++) {
+ sym->st_shndx = TO_NATIVE(sym->st_shndx);
+ sym->st_name = TO_NATIVE(sym->st_name);
+ sym->st_value = TO_NATIVE(sym->st_value);
+ sym->st_size = TO_NATIVE(sym->st_size);
+ }
+ return;
+
+ truncated:
+ fprintf(stderr, "modpost: %s is truncated.\n", filename);
+ abort();
+}
+
+void
+parse_elf_finish(struct elf_info *info)
+{
+ release_file(info->hdr, info->size);
+}
+
+#define CRC_PFX MODULE_SYMBOL_PREFIX "__crc_"
+#define KSYMTAB_PFX MODULE_SYMBOL_PREFIX "__ksymtab_"
+
+void
+handle_modversions(struct module *mod, struct elf_info *info,
+ Elf_Sym *sym, const char *symname)
+{
+ unsigned int crc;
+
+ switch (sym->st_shndx) {
+ case SHN_COMMON:
+ fprintf(stderr, "*** Warning: \"%s\" [%s] is COMMON symbol\n",
+ symname, mod->name);
+ break;
+ case SHN_ABS:
+ /* CRC'd symbol */
+ if (memcmp(symname, CRC_PFX, strlen(CRC_PFX)) == 0) {
+ crc = (unsigned int) sym->st_value;
+ add_exported_symbol(symname + strlen(CRC_PFX),
+ mod, &crc);
+ modversions = 1;
+ }
+ break;
+ case SHN_UNDEF:
+ /* undefined symbol */
+ if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL)
+ break;
+ /* ignore global offset table */
+ if (strcmp(symname, "_GLOBAL_OFFSET_TABLE_") == 0)
+ break;
+ /* ignore __this_module, it will be resolved shortly */
+ if (strcmp(symname, MODULE_SYMBOL_PREFIX "__this_module") == 0)
+ break;
+#ifdef STT_REGISTER
+ if (info->hdr->e_machine == EM_SPARC ||
+ info->hdr->e_machine == EM_SPARCV9) {
+ /* Ignore register directives. */
+ if (ELF_ST_TYPE(sym->st_info) == STT_REGISTER)
+ break;
+ }
+#endif
+
+ if (memcmp(symname, MODULE_SYMBOL_PREFIX,
+ strlen(MODULE_SYMBOL_PREFIX)) == 0)
+ mod->unres = alloc_symbol(symname +
+ strlen(MODULE_SYMBOL_PREFIX),
+ mod->unres);
+ break;
+ default:
+ /* All exported symbols */
+ if (memcmp(symname, KSYMTAB_PFX, strlen(KSYMTAB_PFX)) == 0) {
+ add_exported_symbol(symname + strlen(KSYMTAB_PFX),
+ mod, NULL);
+ }
+ break;
+ }
+}
+
+int
+is_vmlinux(const char *modname)
+{
+ const char *myname;
+
+ if ((myname = strrchr(modname, '/')))
+ myname++;
+ else
+ myname = modname;
+
+ return strcmp(myname, "vmlinux") == 0;
+}
+
+void
+read_symbols(char *modname)
+{
+ const char *symname;
+ struct module *mod;
+ struct elf_info info = { };
+ Elf_Sym *sym;
+
+ parse_elf(&info, modname);
+
+ mod = new_module(modname);
+
+ /* When there's no vmlinux, don't print warnings about
+ * unresolved symbols (since there'll be too many ;) */
+ if (is_vmlinux(modname)) {
+ unsigned int fake_crc = 0;
+ have_vmlinux = 1;
+ /* May not have this if !CONFIG_MODULE_UNLOAD: fake it.
+ If it appears, we'll get the real CRC. */
+ add_exported_symbol("cleanup_module", mod, &fake_crc);
+ add_exported_symbol("struct_module", mod, &fake_crc);
+ mod->skip = 1;
+ }
+
+ for (sym = info.symtab_start; sym < info.symtab_stop; sym++) {
+ symname = info.strtab + sym->st_name;
+
+ handle_modversions(mod, &info, sym, symname);
+ handle_moddevtable(mod, &info, sym, symname);
+ }
+ maybe_frob_version(modname, info.modinfo, info.modinfo_len,
+ (void *)info.modinfo - (void *)info.hdr);
+ parse_elf_finish(&info);
+
+ /* Our trick to get versioning for struct_module - 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("struct_module", mod->unres);
+
+ /* Always version init_module and cleanup_module, in
+ * case module doesn't have its own. */
+ mod->unres = alloc_symbol("init_module", mod->unres);
+ mod->unres = alloc_symbol("cleanup_module", mod->unres);
+ }
+}
+
+#define SZ 500
+
+/* We first write the generated file into memory using the
+ * following helper, then compare to the file on disk and
+ * only update the later if anything changed */
+
+void __attribute__((format(printf, 2, 3)))
+buf_printf(struct buffer *buf, const char *fmt, ...)
+{
+ char tmp[SZ];
+ int len;
+ va_list ap;
+
+ va_start(ap, fmt);
+ len = vsnprintf(tmp, SZ, fmt, ap);
+ if (buf->size - buf->pos < len + 1) {
+ buf->size += 128;
+ buf->p = realloc(buf->p, buf->size);
+ }
+ strncpy(buf->p + buf->pos, tmp, len + 1);
+ buf->pos += len;
+ va_end(ap);
+}
+
+void
+buf_write(struct buffer *buf, const char *s, int len)
+{
+ if (buf->size - buf->pos < len) {
+ buf->size += len;
+ buf->p = realloc(buf->p, buf->size);
+ }
+ strncpy(buf->p + buf->pos, s, len);
+ buf->pos += len;
+}
+
+/* Header for the generated file */
+
+void
+add_header(struct buffer *b)
+{
+ buf_printf(b, "#include <linux/module.h>\n");
+ buf_printf(b, "#include <linux/vermagic.h>\n");
+ buf_printf(b, "#include <linux/compiler.h>\n");
+ buf_printf(b, "\n");
+ buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n");
+ buf_printf(b, "\n");
+ buf_printf(b, "#undef unix\n"); /* We have a module called "unix" */
+ buf_printf(b, "struct module __this_module\n");
+ buf_printf(b, "__attribute__((section(\".gnu.linkonce.this_module\"))) = {\n");
+ buf_printf(b, " .name = __stringify(KBUILD_MODNAME),\n");
+ buf_printf(b, " .init = init_module,\n");
+ buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n");
+ buf_printf(b, " .exit = cleanup_module,\n");
+ buf_printf(b, "#endif\n");
+ buf_printf(b, "};\n");
+}
+
+/* Record CRCs for unresolved symbols */
+
+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) {
+ if (have_vmlinux)
+ fprintf(stderr, "*** Warning: \"%s\" [%s.ko] "
+ "undefined!\n", s->name, mod->name);
+ continue;
+ }
+ s->module = exp->module;
+ s->crc_valid = exp->crc_valid;
+ s->crc = exp->crc;
+ }
+
+ if (!modversions)
+ return;
+
+ buf_printf(b, "\n");
+ buf_printf(b, "static const struct modversion_info ____versions[]\n");
+ buf_printf(b, "__attribute_used__\n");
+ buf_printf(b, "__attribute__((section(\"__versions\"))) = {\n");
+
+ for (s = mod->unres; s; s = s->next) {
+ if (!s->module) {
+ continue;
+ }
+ if (!s->crc_valid) {
+ fprintf(stderr, "*** Warning: \"%s\" [%s.ko] "
+ "has no CRC!\n",
+ s->name, mod->name);
+ continue;
+ }
+ buf_printf(b, "\t{ %#8x, \"%s\" },\n", s->crc, s->name);
+ }
+
+ buf_printf(b, "};\n");
+}
+
+void
+add_depends(struct buffer *b, struct module *mod, struct module *modules)
+{
+ struct symbol *s;
+ struct module *m;
+ int first = 1;
+
+ for (m = modules; m; m = m->next) {
+ m->seen = is_vmlinux(m->name);
+ }
+
+ buf_printf(b, "\n");
+ buf_printf(b, "static const char __module_depends[]\n");
+ buf_printf(b, "__attribute_used__\n");
+ buf_printf(b, "__attribute__((section(\".modinfo\"))) =\n");
+ buf_printf(b, "\"depends=");
+ for (s = mod->unres; s; s = s->next) {
+ if (!s->module)
+ continue;
+
+ if (s->module->seen)
+ continue;
+
+ s->module->seen = 1;
+ buf_printf(b, "%s%s", first ? "" : ",",
+ strrchr(s->module->name, '/') + 1);
+ first = 0;
+ }
+ buf_printf(b, "\";\n");
+}
+
+void
+write_if_changed(struct buffer *b, const char *fname)
+{
+ char *tmp;
+ FILE *file;
+ struct stat st;
+
+ file = fopen(fname, "r");
+ if (!file)
+ goto write;
+
+ if (fstat(fileno(file), &st) < 0)
+ goto close_write;
+
+ if (st.st_size != b->pos)
+ goto close_write;
+
+ tmp = NOFAIL(malloc(b->pos));
+ if (fread(tmp, 1, b->pos, file) != b->pos)
+ goto free_write;
+
+ if (memcmp(tmp, b->p, b->pos) != 0)
+ goto free_write;
+
+ free(tmp);
+ fclose(file);
+ return;
+
+ free_write:
+ free(tmp);
+ close_write:
+ fclose(file);
+ write:
+ file = fopen(fname, "w");
+ if (!file) {
+ perror(fname);
+ exit(1);
+ }
+ if (fwrite(b->p, 1, b->pos, file) != b->pos) {
+ perror(fname);
+ exit(1);
+ }
+ fclose(file);
+}
+
+void
+read_dump(const char *fname)
+{
+ unsigned long size, pos = 0;
+ void *file = grab_file(fname, &size);
+ char *line;
+
+ if (!file)
+ /* No symbol versions, silently ignore */
+ return;
+
+ while ((line = get_next_line(&pos, file, size))) {
+ char *symname, *modname, *d;
+ unsigned int crc;
+ struct module *mod;
+
+ if (!(symname = strchr(line, '\t')))
+ goto fail;
+ *symname++ = '\0';
+ if (!(modname = strchr(symname, '\t')))
+ goto fail;
+ *modname++ = '\0';
+ if (strchr(modname, '\t'))
+ goto fail;
+ crc = strtoul(line, &d, 16);
+ if (*symname == '\0' || *modname == '\0' || *d != '\0')
+ goto fail;
+
+ if (!(mod = find_module(modname))) {
+ if (is_vmlinux(modname)) {
+ modversions = 1;
+ have_vmlinux = 1;
+ }
+ mod = new_module(NOFAIL(strdup(modname)));
+ mod->skip = 1;
+ }
+ add_exported_symbol(symname, mod, &crc);
+ }
+ return;
+fail:
+ fatal("parse error in symbol dump file\n");
+}
+
+void
+write_dump(const char *fname)
+{
+ struct buffer buf = { };
+ struct symbol *symbol;
+ int n;
+
+ for (n = 0; n < SYMBOL_HASH_SIZE ; n++) {
+ symbol = symbolhash[n];
+ while (symbol) {
+ symbol = symbol->next;
+ }
+ }
+
+ for (n = 0; n < SYMBOL_HASH_SIZE ; n++) {
+ symbol = symbolhash[n];
+ while (symbol) {
+ buf_printf(&buf, "0x%08x\t%s\t%s\n", symbol->crc,
+ symbol->name, symbol->module->name);
+ symbol = symbol->next;
+ }
+ }
+ write_if_changed(&buf, fname);
+}
+
+int
+main(int argc, char **argv)
+{
+ struct module *mod;
+ struct buffer buf = { };
+ char fname[SZ];
+ char *dump_read = NULL, *dump_write = NULL;
+ int opt;
+
+ while ((opt = getopt(argc, argv, "i:o:")) != -1) {
+ switch(opt) {
+ case 'i':
+ dump_read = optarg;
+ break;
+ case 'o':
+ dump_write = optarg;
+ break;
+ default:
+ exit(1);
+ }
+ }
+
+ if (dump_read)
+ read_dump(dump_read);
+
+ while (optind < argc) {
+ read_symbols(argv[optind++]);
+ }
+
+ for (mod = modules; mod; mod = mod->next) {
+ if (mod->skip)
+ continue;
+
+ buf.pos = 0;
+
+ add_header(&buf);
+ add_versions(&buf, mod);
+ add_depends(&buf, mod, modules);
+ add_moddevtable(&buf, mod);
+
+ sprintf(fname, "%s.mod.c", mod->name);
+ write_if_changed(&buf, fname);
+ }
+
+ if (dump_write)
+ write_dump(dump_write);
+
+ return 0;
+}
+
git://git.onelab.eu / linux-2.6.git / blobdiff