1 files changed, 797 insertions, 0 deletions

diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
new file mode 100644
index 000000000000..9b9f94c915d2
--- /dev/null
+++ b/scripts/mod/modpost.c
@@ -0,0 +1,797 @@
+/* Postprocess module symbol versions
+ *
+ * Copyright 2003       Kai Germaschewski
+ * Copyright 2002-2004  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;
+/* Is CONFIG_MODULE_SRCVERSION_ALL set? */
+static int all_versions = 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 *expr)
+{
+        if (!ptr) {
+                fatal("modpost: Memory allocation failure: %s.\n", 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;
+        unsigned int weak:1;
+        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, unsigned int weak, struct symbol *next)
+{
+        struct symbol *s = NOFAIL(malloc(sizeof(*s) + strlen(name) + 1));
+
+        memset(s, 0, sizeof(*s));
+        strcpy(s->name, name);
+        s->weak = weak;
+        s->next = next;
+        return s;
+}
+
+/* For the hash of exported symbols */
+
+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, 0, 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;
+        signed char *p = (signed char *)file + *pos;
+        char *s = line;
+
+        for (; *pos < size ; (*pos)++)
+        {
+                if (skip && isspace(*p)) {
+                        p++;
+                        continue;
+                }
+                skip = 0;
+                if (*p != '\n' && (*pos < size)) {
+                        len++;
+                        *s++ = *p++;
+                        if (len > 4095)
+                                break; /* Too long, stop */
+                } else {
+                        /* End of string */
+                        *s = '\0';
+                        return line;
+                }
+        }
+        /* End of buffer */
+        return NULL;
+}
+
+void
+release_file(void *file, unsigned long size)
+{
+        munmap(file, size);
+}
+
+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);
+                }
+                break;
+        case SHN_UNDEF:
+                /* undefined symbol */
+                if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL &&
+                    ELF_ST_BIND(sym->st_info) != STB_WEAK)
+                        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),
+                                                  ELF_ST_BIND(sym->st_info) == STB_WEAK,
+                                                  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);
+                }
+                if (strcmp(symname, MODULE_SYMBOL_PREFIX "init_module") == 0)
+                        mod->has_init = 1;
+                if (strcmp(symname, MODULE_SYMBOL_PREFIX "cleanup_module") == 0)
+                        mod->has_cleanup = 1;
+                break;
+        }
+}
+
+int
+is_vmlinux(const char *modname)
+{
+        const char *myname;
+
+        if ((myname = strrchr(modname, '/')))
+                myname++;
+        else
+                myname = modname;
+
+        return strcmp(myname, "vmlinux") == 0;
+}
+
+/* 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_modinfo(void *modinfo, unsigned long modinfo_len,
+                         const char *tag)
+{
+        char *p;
+        unsigned int taglen = strlen(tag);
+        unsigned long size = modinfo_len;
+
+        for (p = modinfo; p; p = next_string(p, &size)) {
+                if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
+                        return p + taglen + 1;
+        }
+        return NULL;
+}
+
+void
+read_symbols(char *modname)
+{
+        const char *symname;
+        char *version;
+        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;
+                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);
+        }
+
+        version = get_modinfo(info.modinfo, info.modinfo_len, "version");
+        if (version)
+                maybe_frob_rcs_version(modname, version, info.modinfo,
+                                       version - (char *)info.hdr);
+        if (version || (all_versions && !is_vmlinux(modname)))
+                get_src_version(modname, mod->srcversion,
+                                sizeof(mod->srcversion)-1);
+
+        parse_elf_finish(&info);
+
+        /* Our trick to get versioning for 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", 0, mod->unres);
+}
+
+#define SZ 500
+
+/* We first write the generated file into memory using the
+ * following helper, then compare to the file on disk and
+ * only update the later if anything changed */
+
+void __attribute__((format(printf, 2, 3)))
+buf_printf(struct buffer *buf, const char *fmt, ...)
+{
+        char tmp[SZ];
+        int len;
+        va_list ap;
+        
+        va_start(ap, fmt);
+        len = vsnprintf(tmp, SZ, fmt, ap);
+        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, struct module *mod)
+{
+        buf_printf(b, "#include <linux/module.h>\n");
+        buf_printf(b, "#include <linux/vermagic.h>\n");
+        buf_printf(b, "#include <linux/compiler.h>\n");
+        buf_printf(b, "\n");
+        buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n");
+        buf_printf(b, "\n");
+        buf_printf(b, "#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");
+        if (mod->has_init)
+                buf_printf(b, " .init = init_module,\n");
+        if (mod->has_cleanup)
+                buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n"
+                              " .exit = cleanup_module,\n"
+                              "#endif\n");
+        buf_printf(b, "};\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 && !s->weak)
+                                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
+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);
+        }
+}
+
+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)) {
+                                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:mo:a")) != -1) {
+                switch(opt) {
+                        case 'i':
+                                dump_read = optarg;
+                                break;
+                        case 'm':
+                                modversions = 1;
+                                break;
+                        case 'o':
+                                dump_write = optarg;
+                                break;
+                        case 'a':
+                                all_versions = 1;
+                                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, mod);
+                add_versions(&buf, mod);
+                add_depends(&buf, mod, modules);
+                add_moddevtable(&buf, mod);
+                add_srcversion(&buf, mod);
+
+                sprintf(fname, "%s.mod.c", mod->name);
+                write_if_changed(&buf, fname);
+        }
+
+        if (dump_write)
+                write_dump(dump_write);
+
+        return 0;
+}
+