kbuild: remove hardcoded apic_es7000 from modpost
[safe/jmp/linux-2.6] / scripts / mod / modpost.c
index 976adf1..1921c43 100644 (file)
@@ -2,7 +2,7 @@
  *
  * Copyright 2003       Kai Germaschewski
  * Copyright 2002-2004  Rusty Russell, IBM Corporation
- *
+ * Copyright 2006       Sam Ravnborg
  * Based in part on module-init-tools/depmod.c,file2alias
  *
  * This software may be used and distributed according to the terms
@@ -13,6 +13,7 @@
 
 #include <ctype.h>
 #include "modpost.h"
+#include "../../include/linux/license.h"
 
 /* Are we using CONFIG_MODVERSIONS? */
 int modversions = 0;
@@ -22,6 +23,13 @@ int have_vmlinux = 0;
 static int all_versions = 0;
 /* If we are modposting external module set to 1 */
 static int external_module = 0;
+/* Only warn about unresolved symbols */
+static int warn_unresolved = 0;
+/* How a symbol is exported */
+enum export {
+       export_plain,      export_unused,     export_gpl,
+       export_unused_gpl, export_gpl_future, export_unknown
+};
 
 void fatal(const char *fmt, ...)
 {
@@ -47,6 +55,17 @@ void warn(const char *fmt, ...)
        va_end(arglist);
 }
 
+void merror(const char *fmt, ...)
+{
+       va_list arglist;
+
+       fprintf(stderr, "ERROR: ");
+
+       va_start(arglist, fmt);
+       vfprintf(stderr, fmt, arglist);
+       va_end(arglist);
+}
+
 static int is_vmlinux(const char *modname)
 {
        const char *myname;
@@ -85,7 +104,7 @@ static struct module *new_module(char *modname)
 {
        struct module *mod;
        char *p, *s;
-       
+
        mod = NOFAIL(malloc(sizeof(*mod)));
        memset(mod, 0, sizeof(*mod));
        p = NOFAIL(strdup(modname));
@@ -97,6 +116,7 @@ static struct module *new_module(char *modname)
 
        /* add to list */
        mod->name = p;
+       mod->gpl_compatible = -1;
        mod->next = modules;
        modules = mod;
 
@@ -117,6 +137,8 @@ struct symbol {
        unsigned int vmlinux:1;    /* 1 if symbol is defined in vmlinux */
        unsigned int kernel:1;     /* 1 if symbol is from kernel
                                    *  (only for external modules) **/
+       unsigned int preloaded:1;  /* 1 if symbol from Module.symvers */
+       enum export  export;       /* Type of export */
        char name[0];
 };
 
@@ -152,7 +174,8 @@ static struct symbol *alloc_symbol(const char *name, unsigned int weak,
 }
 
 /* For the hash of exported symbols */
-static struct symbol *new_symbol(const char *name, struct module *module)
+static struct symbol *new_symbol(const char *name, struct module *module,
+                                enum export export)
 {
        unsigned int hash;
        struct symbol *new;
@@ -160,6 +183,7 @@ static struct symbol *new_symbol(const char *name, struct module *module)
        hash = tdb_hash(name) % SYMBOL_HASH_SIZE;
        new = symbolhash[hash] = alloc_symbol(name, 0, symbolhash[hash]);
        new->module = module;
+       new->export = export;
        return new;
 }
 
@@ -178,29 +202,85 @@ static struct symbol *find_symbol(const char *name)
        return NULL;
 }
 
+static struct {
+       const char *str;
+       enum export export;
+} export_list[] = {
+       { .str = "EXPORT_SYMBOL",            .export = export_plain },
+       { .str = "EXPORT_UNUSED_SYMBOL",     .export = export_unused },
+       { .str = "EXPORT_SYMBOL_GPL",        .export = export_gpl },
+       { .str = "EXPORT_UNUSED_SYMBOL_GPL", .export = export_unused_gpl },
+       { .str = "EXPORT_SYMBOL_GPL_FUTURE", .export = export_gpl_future },
+       { .str = "(unknown)",                .export = export_unknown },
+};
+
+
+static const char *export_str(enum export ex)
+{
+       return export_list[ex].str;
+}
+
+static enum export export_no(const char * s)
+{
+       int i;
+       if (!s)
+               return export_unknown;
+       for (i = 0; export_list[i].export != export_unknown; i++) {
+               if (strcmp(export_list[i].str, s) == 0)
+                       return export_list[i].export;
+       }
+       return export_unknown;
+}
+
+static enum export export_from_sec(struct elf_info *elf, Elf_Section sec)
+{
+       if (sec == elf->export_sec)
+               return export_plain;
+       else if (sec == elf->export_unused_sec)
+               return export_unused;
+       else if (sec == elf->export_gpl_sec)
+               return export_gpl;
+       else if (sec == elf->export_unused_gpl_sec)
+               return export_unused_gpl;
+       else if (sec == elf->export_gpl_future_sec)
+               return export_gpl_future;
+       else
+               return export_unknown;
+}
+
 /**
  * Add an exported symbol - it may have already been added without a
  * CRC, in this case just update the CRC
  **/
-static struct symbol *sym_add_exported(const char *name, struct module *mod)
+static struct symbol *sym_add_exported(const char *name, struct module *mod,
+                                      enum export export)
 {
        struct symbol *s = find_symbol(name);
 
-       if (!s)
-               s = new_symbol(name, mod);
-
+       if (!s) {
+               s = new_symbol(name, mod, export);
+       } else {
+               if (!s->preloaded) {
+                       warn("%s: '%s' exported twice. Previous export "
+                            "was in %s%s\n", mod->name, name,
+                            s->module->name,
+                            is_vmlinux(s->module->name) ?"":".ko");
+               }
+       }
+       s->preloaded = 0;
        s->vmlinux   = is_vmlinux(mod->name);
        s->kernel    = 0;
+       s->export    = export;
        return s;
 }
 
 static void sym_update_crc(const char *name, struct module *mod,
-                          unsigned int crc)
+                          unsigned int crc, enum export export)
 {
        struct symbol *s = find_symbol(name);
 
        if (!s)
-               s = new_symbol(name, mod);
+               s = new_symbol(name, mod, export);
        s->crc = crc;
        s->crc_valid = 1;
 }
@@ -264,27 +344,37 @@ void release_file(void *file, unsigned long size)
        munmap(file, size);
 }
 
-static void parse_elf(struct elf_info *info, const char *filename)
+static int parse_elf(struct elf_info *info, const char *filename)
 {
        unsigned int i;
-       Elf_Ehdr *hdr = info->hdr;
+       Elf_Ehdr *hdr;
        Elf_Shdr *sechdrs;
        Elf_Sym  *sym;
 
        hdr = grab_file(filename, &info->size);
        if (!hdr) {
                perror(filename);
-               abort();
+               exit(1);
        }
        info->hdr = hdr;
-       if (info->size < sizeof(*hdr))
-               goto truncated;
-
+       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_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);
+       hdr->e_type     = TO_NATIVE(hdr->e_type);
        sechdrs = (void *)hdr + hdr->e_shoff;
        info->sechdrs = sechdrs;
 
@@ -295,25 +385,41 @@ static void parse_elf(struct elf_info *info, const char *filename)
                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);
+               sechdrs[i].sh_info   = TO_NATIVE(sechdrs[i].sh_info);
+               sechdrs[i].sh_addr   = TO_NATIVE(sechdrs[i].sh_addr);
        }
        /* Find symbol table. */
        for (i = 1; i < hdr->e_shnum; i++) {
                const char *secstrings
                        = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
+               const char *secname;
 
-               if (sechdrs[i].sh_offset > info->size)
-                       goto truncated;
-               if (strcmp(secstrings+sechdrs[i].sh_name, ".modinfo") == 0) {
+               if (sechdrs[i].sh_offset > info->size) {
+                       fatal("%s is truncated. sechdrs[i].sh_offset=%u > sizeof(*hrd)=%ul\n", filename, (unsigned int)sechdrs[i].sh_offset, sizeof(*hdr));
+                       return 0;
+               }
+               secname = secstrings + sechdrs[i].sh_name;
+               if (strcmp(secname, ".modinfo") == 0) {
                        info->modinfo = (void *)hdr + sechdrs[i].sh_offset;
                        info->modinfo_len = sechdrs[i].sh_size;
-               }
+               } else if (strcmp(secname, "__ksymtab") == 0)
+                       info->export_sec = i;
+               else if (strcmp(secname, "__ksymtab_unused") == 0)
+                       info->export_unused_sec = i;
+               else if (strcmp(secname, "__ksymtab_gpl") == 0)
+                       info->export_gpl_sec = i;
+               else if (strcmp(secname, "__ksymtab_unused_gpl") == 0)
+                       info->export_unused_gpl_sec = i;
+               else if (strcmp(secname, "__ksymtab_gpl_future") == 0)
+                       info->export_gpl_future_sec = i;
+
                if (sechdrs[i].sh_type != SHT_SYMTAB)
                        continue;
 
                info->symtab_start = (void *)hdr + sechdrs[i].sh_offset;
-               info->symtab_stop  = (void *)hdr + sechdrs[i].sh_offset 
+               info->symtab_stop  = (void *)hdr + sechdrs[i].sh_offset
                                                 + sechdrs[i].sh_size;
-               info->strtab       = (void *)hdr + 
+               info->strtab       = (void *)hdr +
                                     sechdrs[sechdrs[i].sh_link].sh_offset;
        }
        if (!info->symtab_start) {
@@ -326,10 +432,7 @@ static void parse_elf(struct elf_info *info, const char *filename)
                sym->st_value = TO_NATIVE(sym->st_value);
                sym->st_size  = TO_NATIVE(sym->st_size);
        }
-       return;
-
- truncated:
-       fatal("%s is truncated.\n", filename);
+       return 1;
 }
 
 static void parse_elf_finish(struct elf_info *info)
@@ -337,13 +440,14 @@ static void parse_elf_finish(struct elf_info *info)
        release_file(info->hdr, info->size);
 }
 
-#define CRC_PFX     "__crc_"
-#define KSYMTAB_PFX "__ksymtab_"
+#define CRC_PFX     MODULE_SYMBOL_PREFIX "__crc_"
+#define KSYMTAB_PFX MODULE_SYMBOL_PREFIX "__ksymtab_"
 
 static void handle_modversions(struct module *mod, struct elf_info *info,
                               Elf_Sym *sym, const char *symname)
 {
        unsigned int crc;
+       enum export export = export_from_sec(info, sym->st_shndx);
 
        switch (sym->st_shndx) {
        case SHN_COMMON:
@@ -353,7 +457,8 @@ static void handle_modversions(struct module *mod, struct elf_info *info,
                /* CRC'd symbol */
                if (memcmp(symname, CRC_PFX, strlen(CRC_PFX)) == 0) {
                        crc = (unsigned int) sym->st_value;
-                       sym_update_crc(symname + strlen(CRC_PFX), mod, crc);
+                       sym_update_crc(symname + strlen(CRC_PFX), mod, crc,
+                                       export);
                }
                break;
        case SHN_UNDEF:
@@ -378,15 +483,15 @@ static void handle_modversions(struct module *mod, struct elf_info *info,
                        /* Ignore register directives. */
                        if (ELF_ST_TYPE(sym->st_info) == STT_SPARC_REGISTER)
                                break;
-                       if (symname[0] == '.') {
-                               char *munged = strdup(symname);
-                               munged[0] = '_';
-                               munged[1] = toupper(munged[1]);
-                               symname = munged;
-                       }
+                       if (symname[0] == '.') {
+                               char *munged = strdup(symname);
+                               munged[0] = '_';
+                               munged[1] = toupper(munged[1]);
+                               symname = munged;
+                       }
                }
 #endif
-               
+
                if (memcmp(symname, MODULE_SYMBOL_PREFIX,
                           strlen(MODULE_SYMBOL_PREFIX)) == 0)
                        mod->unres = alloc_symbol(symname +
@@ -397,7 +502,8 @@ static void handle_modversions(struct module *mod, struct elf_info *info,
        default:
                /* All exported symbols */
                if (memcmp(symname, KSYMTAB_PFX, strlen(KSYMTAB_PFX)) == 0) {
-                       sym_add_exported(symname + strlen(KSYMTAB_PFX), mod);
+                       sym_add_exported(symname + strlen(KSYMTAB_PFX), mod,
+                                       export);
                }
                if (strcmp(symname, MODULE_SYMBOL_PREFIX "init_module") == 0)
                        mod->has_init = 1;
@@ -428,13 +534,18 @@ static char *next_string(char *string, unsigned long *secsize)
        return string;
 }
 
-static char *get_modinfo(void *modinfo, unsigned long modinfo_len,
-                        const char *tag)
+static char *get_next_modinfo(void *modinfo, unsigned long modinfo_len,
+                             const char *tag, char *info)
 {
        char *p;
        unsigned int taglen = strlen(tag);
        unsigned long size = modinfo_len;
 
+       if (info) {
+               size -= info - (char *)modinfo;
+               modinfo = next_string(info, &size);
+       }
+
        for (p = modinfo; p; p = next_string(p, &size)) {
                if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
                        return p + taglen + 1;
@@ -442,15 +553,690 @@ static char *get_modinfo(void *modinfo, unsigned long modinfo_len,
        return NULL;
 }
 
+static char *get_modinfo(void *modinfo, unsigned long modinfo_len,
+                        const char *tag)
+
+{
+       return get_next_modinfo(modinfo, modinfo_len, tag, NULL);
+}
+
+/**
+ * Test if string s ends in string sub
+ * return 0 if match
+ **/
+static int strrcmp(const char *s, const char *sub)
+{
+        int slen, sublen;
+
+       if (!s || !sub)
+               return 1;
+
+       slen = strlen(s);
+        sublen = strlen(sub);
+
+       if ((slen == 0) || (sublen == 0))
+               return 1;
+
+        if (sublen > slen)
+                return 1;
+
+        return memcmp(s + slen - sublen, sub, sublen);
+}
+
+/**
+ * Whitelist to allow certain references to pass with no warning.
+ *
+ * Pattern 0:
+ *   Do not warn if funtion/data are marked with __init_refok/__initdata_refok.
+ *   The pattern is identified by:
+ *   fromsec = .text.init.refok | .data.init.refok
+ *
+ * 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 2:
+ *   Many drivers utilise a *driver container with references to
+ *   add, remove, probe functions etc.
+ *   These functions may often be marked __init and we do not want to
+ *   warn here.
+ *   the pattern is identified by:
+ *   tosec   = .init.text | .exit.text | .init.data
+ *   fromsec = .data
+ *   atsym = *driver, *_template, *_sht, *_ops, *_probe, *probe_one, *_console
+ *
+ * Pattern 3:
+ *   Whitelist all refereces from .text.head to .init.data
+ *   Whitelist all refereces from .text.head to .init.text
+ *
+ * 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:
+ *  Logos used in drivers/video/logo reside in __initdata but the
+ *  funtion that references them are EXPORT_SYMBOL() so cannot be
+ *  marker __init. So we whitelist them here.
+ *  The pattern is:
+ *  tosec      = .init.data
+ *  fromsec    = .text*
+ *  refsymname = logo_
+ **/
+static int secref_whitelist(const char *modname, const char *tosec,
+                           const char *fromsec, const char *atsym,
+                           const char *refsymname)
+{
+       int f1 = 1, f2 = 1;
+       const char **s;
+       const char *pat2sym[] = {
+               "driver",
+               "_template", /* scsi uses *_template a lot */
+               "_sht",      /* scsi also used *_sht to some extent */
+               "_ops",
+               "_probe",
+               "_probe_one",
+               "_console",
+               NULL
+       };
+
+       const char *pat3refsym[] = {
+               "__init_begin",
+               "_sinittext",
+               "_einittext",
+               NULL
+       };
+
+       /* Check for pattern 0 */
+       if ((strcmp(fromsec, ".text.init.refok") == 0) ||
+           (strcmp(fromsec, ".data.init.refok") == 0))
+               return 1;
+
+       /* Check for pattern 1 */
+       if (strcmp(tosec, ".init.data") != 0)
+               f1 = 0;
+       if (strncmp(fromsec, ".data", strlen(".data")) != 0)
+               f1 = 0;
+       if (strncmp(atsym, "__param", strlen("__param")) != 0)
+               f1 = 0;
+
+       if (f1)
+               return f1;
+
+       /* Check for pattern 2 */
+       if ((strcmp(tosec, ".init.text") != 0) &&
+           (strcmp(tosec, ".exit.text") != 0) &&
+           (strcmp(tosec, ".init.data") != 0))
+               f2 = 0;
+       if (strcmp(fromsec, ".data") != 0)
+               f2 = 0;
+
+       for (s = pat2sym; *s; s++)
+               if (strrcmp(atsym, *s) == 0)
+                       f1 = 1;
+       if (f1 && f2)
+               return 1;
+
+       /* Check for pattern 3 */
+       if ((strcmp(fromsec, ".text.head") == 0) &&
+               ((strcmp(tosec, ".init.data") == 0) ||
+               (strcmp(tosec, ".init.text") == 0)))
+       return 1;
+
+       /* Check for pattern 4 */
+       for (s = pat3refsym; *s; s++)
+               if (strcmp(refsymname, *s) == 0)
+                       return 1;
+
+       /* Check for pattern 5 */
+       if ((strcmp(tosec, ".init.data") == 0) &&
+           (strncmp(fromsec, ".text", strlen(".text")) == 0) &&
+           (strncmp(refsymname, "logo_", strlen("logo_")) == 0))
+               return 1;
+
+       return 0;
+}
+
+/**
+ * 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, Elf_Addr addr,
+                               Elf_Sym *relsym)
+{
+       Elf_Sym *sym;
+
+       if (relsym->st_name != 0)
+               return relsym;
+       for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) {
+               if (sym->st_shndx != relsym->st_shndx)
+                       continue;
+               if (ELF_ST_TYPE(sym->st_info) == STT_SECTION)
+                       continue;
+               if (sym->st_value == addr)
+                       return sym;
+       }
+       return NULL;
+}
+
+static inline int is_arm_mapping_symbol(const char *str)
+{
+       return str[0] == '$' && strchr("atd", str[1])
+              && (str[2] == '\0' || str[2] == '.');
+}
+
+/*
+ * If there's no name there, ignore it; likewise, ignore it if it's
+ * one of the magic symbols emitted used by current ARM tools.
+ *
+ * Otherwise if find_symbols_between() returns those symbols, they'll
+ * fail the whitelist tests and cause lots of false alarms ... fixable
+ * only by merging __exit and __init sections into __text, bloating
+ * the kernel (which is especially evil on embedded platforms).
+ */
+static inline int is_valid_name(struct elf_info *elf, Elf_Sym *sym)
+{
+       const char *name = elf->strtab + sym->st_name;
+
+       if (!name || !strlen(name))
+               return 0;
+       return !is_arm_mapping_symbol(name);
+}
+
+/*
+ * Find symbols before or equal addr and after addr - in the section sec.
+ * If we find two symbols with equal offset prefer one with a valid name.
+ * The ELF format may have a better way to detect what type of symbol
+ * it is, but this works for now.
+ **/
+static void find_symbols_between(struct elf_info *elf, Elf_Addr addr,
+                                const char *sec,
+                                Elf_Sym **before, Elf_Sym **after)
+{
+       Elf_Sym *sym;
+       Elf_Ehdr *hdr = elf->hdr;
+       Elf_Addr beforediff = ~0;
+       Elf_Addr afterdiff = ~0;
+       const char *secstrings = (void *)hdr +
+                                elf->sechdrs[hdr->e_shstrndx].sh_offset;
+
+       *before = NULL;
+       *after = NULL;
+
+       for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) {
+               const char *symsec;
+
+               if (sym->st_shndx >= SHN_LORESERVE)
+                       continue;
+               symsec = secstrings + elf->sechdrs[sym->st_shndx].sh_name;
+               if (strcmp(symsec, sec) != 0)
+                       continue;
+               if (!is_valid_name(elf, sym))
+                       continue;
+               if (sym->st_value <= addr) {
+                       if ((addr - sym->st_value) < beforediff) {
+                               beforediff = addr - sym->st_value;
+                               *before = sym;
+                       }
+                       else if ((addr - sym->st_value) == beforediff) {
+                               *before = sym;
+                       }
+               }
+               else
+               {
+                       if ((sym->st_value - addr) < afterdiff) {
+                               afterdiff = sym->st_value - addr;
+                               *after = sym;
+                       }
+                       else if ((sym->st_value - addr) == afterdiff) {
+                               *after = sym;
+                       }
+               }
+       }
+}
+
+/**
+ * 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 warn_sec_mismatch(const char *modname, const char *fromsec,
+                             struct elf_info *elf, Elf_Sym *sym, Elf_Rela r)
+{
+       const char *refsymname = "";
+       Elf_Sym *before, *after;
+       Elf_Sym *refsym;
+       Elf_Ehdr *hdr = elf->hdr;
+       Elf_Shdr *sechdrs = elf->sechdrs;
+       const char *secstrings = (void *)hdr +
+                                sechdrs[hdr->e_shstrndx].sh_offset;
+       const char *secname = secstrings + sechdrs[sym->st_shndx].sh_name;
+
+       find_symbols_between(elf, r.r_offset, fromsec, &before, &after);
+
+       refsym = find_elf_symbol(elf, r.r_addend, sym);
+       if (refsym && strlen(elf->strtab + refsym->st_name))
+               refsymname = elf->strtab + refsym->st_name;
+
+       /* check whitelist - we may ignore it */
+       if (before &&
+           secref_whitelist(modname, secname, fromsec,
+                            elf->strtab + before->st_name, refsymname))
+               return;
+
+       if (before && after) {
+               warn("%s(%s+0x%llx): Section mismatch: reference to %s:%s "
+                    "(between '%s' and '%s')\n",
+                    modname, fromsec, (unsigned long long)r.r_offset,
+                    secname, refsymname,
+                    elf->strtab + before->st_name,
+                    elf->strtab + after->st_name);
+       } else if (before) {
+               warn("%s(%s+0x%llx): Section mismatch: reference to %s:%s "
+                    "(after '%s')\n",
+                    modname, fromsec, (unsigned long long)r.r_offset,
+                    secname, refsymname,
+                    elf->strtab + before->st_name);
+       } else if (after) {
+               warn("%s(%s+0x%llx): Section mismatch: reference to %s:%s "
+                    "before '%s' (at offset -0x%llx)\n",
+                    modname, fromsec, (unsigned long long)r.r_offset,
+                    secname, refsymname,
+                    elf->strtab + after->st_name);
+       } else {
+               warn("%s(%s+0x%llx): Section mismatch: reference to %s:%s\n",
+                    modname, fromsec, (unsigned long long)r.r_offset,
+                    secname, refsymname);
+       }
+}
+
+static unsigned int *reloc_location(struct elf_info *elf,
+                                          int rsection, Elf_Rela *r)
+{
+       Elf_Shdr *sechdrs = elf->sechdrs;
+       int section = sechdrs[rsection].sh_info;
+
+       return (void *)elf->hdr + sechdrs[section].sh_offset +
+               (r->r_offset - sechdrs[section].sh_addr);
+}
+
+static int addend_386_rel(struct elf_info *elf, int rsection, Elf_Rela *r)
+{
+       unsigned int r_typ = ELF_R_TYPE(r->r_info);
+       unsigned int *location = reloc_location(elf, rsection, r);
+
+       switch (r_typ) {
+       case R_386_32:
+               r->r_addend = TO_NATIVE(*location);
+               break;
+       case R_386_PC32:
+               r->r_addend = TO_NATIVE(*location) + 4;
+               /* For CONFIG_RELOCATABLE=y */
+               if (elf->hdr->e_type == ET_EXEC)
+                       r->r_addend += r->r_offset;
+               break;
+       }
+       return 0;
+}
+
+static int addend_arm_rel(struct elf_info *elf, int rsection, Elf_Rela *r)
+{
+       unsigned int r_typ = ELF_R_TYPE(r->r_info);
+
+       switch (r_typ) {
+       case R_ARM_ABS32:
+               /* From ARM ABI: (S + A) | T */
+               r->r_addend = (int)(long)(elf->symtab_start + ELF_R_SYM(r->r_info));
+               break;
+       case R_ARM_PC24:
+               /* From ARM ABI: ((S + A) | T) - P */
+               r->r_addend = (int)(long)(elf->hdr + elf->sechdrs[rsection].sh_offset +
+                                         (r->r_offset - elf->sechdrs[rsection].sh_addr));
+               break;
+       default:
+               return 1;
+       }
+       return 0;
+}
+
+static int addend_mips_rel(struct elf_info *elf, int rsection, Elf_Rela *r)
+{
+       unsigned int r_typ = ELF_R_TYPE(r->r_info);
+       unsigned int *location = reloc_location(elf, rsection, 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;
+}
+
+/**
+ * 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 intialized.
+ * Likewise for modules used built-in the sections marked __exit
+ * are discarded because __exit marked function are supposed to be called
+ * only when a moduel is unloaded which never happes for built-in modules.
+ * The check_sec_ref() function traverses all relocation records
+ * to find all references to a section that reference a section that will
+ * be discarded and warns about it.
+ **/
+static void check_sec_ref(struct module *mod, const char *modname,
+                         struct elf_info *elf,
+                         int section(const char*),
+                         int section_ref_ok(const char *))
+{
+       int i;
+       Elf_Sym  *sym;
+       Elf_Ehdr *hdr = elf->hdr;
+       Elf_Shdr *sechdrs = elf->sechdrs;
+       const char *secstrings = (void *)hdr +
+                                sechdrs[hdr->e_shstrndx].sh_offset;
+
+       /* Walk through all sections */
+       for (i = 0; i < hdr->e_shnum; i++) {
+               const char *name = secstrings + sechdrs[i].sh_name;
+               const char *secname;
+               Elf_Rela r;
+               unsigned int r_sym;
+               /* We want to process only relocation sections and not .init */
+               if (sechdrs[i].sh_type == SHT_RELA) {
+                       Elf_Rela *rela;
+                       Elf_Rela *start = (void *)hdr + sechdrs[i].sh_offset;
+                       Elf_Rela *stop  = (void*)start + sechdrs[i].sh_size;
+                       name += strlen(".rela");
+                       if (section_ref_ok(name))
+                               continue;
+
+                       for (rela = start; rela < stop; rela++) {
+                               r.r_offset = TO_NATIVE(rela->r_offset);
+#if KERNEL_ELFCLASS == ELFCLASS64
+                               if (hdr->e_machine == EM_MIPS) {
+                                       unsigned int r_typ;
+                                       r_sym = ELF64_MIPS_R_SYM(rela->r_info);
+                                       r_sym = TO_NATIVE(r_sym);
+                                       r_typ = ELF64_MIPS_R_TYPE(rela->r_info);
+                                       r.r_info = ELF64_R_INFO(r_sym, r_typ);
+                               } else {
+                                       r.r_info = TO_NATIVE(rela->r_info);
+                                       r_sym = ELF_R_SYM(r.r_info);
+                               }
+#else
+                               r.r_info = TO_NATIVE(rela->r_info);
+                               r_sym = ELF_R_SYM(r.r_info);
+#endif
+                               r.r_addend = TO_NATIVE(rela->r_addend);
+                               sym = elf->symtab_start + r_sym;
+                               /* Skip special sections */
+                               if (sym->st_shndx >= SHN_LORESERVE)
+                                       continue;
+
+                               secname = secstrings +
+                                       sechdrs[sym->st_shndx].sh_name;
+                               if (section(secname))
+                                       warn_sec_mismatch(modname, name,
+                                                         elf, sym, r);
+                       }
+               } else if (sechdrs[i].sh_type == SHT_REL) {
+                       Elf_Rel *rel;
+                       Elf_Rel *start = (void *)hdr + sechdrs[i].sh_offset;
+                       Elf_Rel *stop  = (void*)start + sechdrs[i].sh_size;
+                       name += strlen(".rel");
+                       if (section_ref_ok(name))
+                               continue;
+
+                       for (rel = start; rel < stop; rel++) {
+                               r.r_offset = TO_NATIVE(rel->r_offset);
+#if KERNEL_ELFCLASS == ELFCLASS64
+                               if (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 (hdr->e_machine) {
+                               case EM_386:
+                                       if (addend_386_rel(elf, i, &r))
+                                               continue;
+                                       break;
+                               case EM_ARM:
+                                       if(addend_arm_rel(elf, i, &r))
+                                               continue;
+                                       break;
+                               case EM_MIPS:
+                                       if (addend_mips_rel(elf, i, &r))
+                                               continue;
+                                       break;
+                               }
+                               sym = elf->symtab_start + r_sym;
+                               /* Skip special sections */
+                               if (sym->st_shndx >= SHN_LORESERVE)
+                                       continue;
+
+                               secname = secstrings +
+                                       sechdrs[sym->st_shndx].sh_name;
+                               if (section(secname))
+                                       warn_sec_mismatch(modname, name,
+                                                         elf, sym, r);
+                       }
+               }
+       }
+}
+
+/*
+ * Identify sections from which references to either a
+ * .init or a .exit section is OK.
+ *
+ * [OPD] Keith Ownes <kaos@sgi.com> commented:
+ * For our future {in}sanity, add a comment that this is the ppc .opd
+ * section, not the ia64 .opd section.
+ * ia64 .opd should not point to discarded sections.
+ * [.rodata] like for .init.text we ignore .rodata references -same reason
+ */
+static int initexit_section_ref_ok(const char *name)
+{
+       const char **s;
+       /* Absolute section names */
+       const char *namelist1[] = {
+               "__bug_table",          /* used by powerpc for BUG() */
+               "__ex_table",
+               ".altinstructions",
+               ".cranges",             /* used by sh64 */
+               ".fixup",
+               ".machvec",             /* ia64 + powerpc uses these */
+               ".machine.desc",
+               ".opd",                 /* See comment [OPD] */
+               ".parainstructions",
+               ".pdr",
+               ".plt",                 /* seen on ARCH=um build on x86_64. Harmless */
+               ".smp_locks",
+               ".stab",
+               NULL
+       };
+       /* Start of section names */
+       const char *namelist2[] = {
+               ".debug",
+               ".eh_frame",
+               ".note",                /* ignore ELF notes - may contain anything */
+               ".got",                 /* powerpc - global offset table */
+               ".toc",                 /* powerpc - table of contents */
+               NULL
+       };
+       /* part of section name */
+       const char *namelist3 [] = {
+               ".unwind",  /* Sample: IA_64.unwind.exit.text */
+               NULL
+       };
+
+       for (s = namelist1; *s; s++)
+               if (strcmp(*s, name) == 0)
+                       return 1;
+       for (s = namelist2; *s; s++)
+               if (strncmp(*s, name, strlen(*s)) == 0)
+                       return 1;
+       for (s = namelist3; *s; s++)
+               if (strstr(name, *s) != NULL)
+                       return 1;
+       return 0;
+}
+
+/**
+ * Functions used only during module init is marked __init and is stored in
+ * a .init.text section. Likewise data is marked __initdata and stored in
+ * a .init.data section.
+ * If this section is one of these sections return 1
+ * See include/linux/init.h for the details
+ **/
+static int init_section(const char *name)
+{
+       if (strcmp(name, ".init") == 0)
+               return 1;
+       if (strncmp(name, ".init.", strlen(".init.")) == 0)
+               return 1;
+       return 0;
+}
+
+/*
+ * Identify sections from which references to a .init section is OK.
+ *
+ * Unfortunately references to read only data that referenced .init
+ * sections had to be excluded. Almost all of these are false
+ * positives, they are created by gcc. The downside of excluding rodata
+ * is that there really are some user references from rodata to
+ * init code, e.g. drivers/video/vgacon.c:
+ *
+ * const struct consw vga_con = {
+ *        con_startup:            vgacon_startup,
+ *
+ * where vgacon_startup is __init.  If you want to wade through the false
+ * positives, take out the check for rodata.
+ */
+static int init_section_ref_ok(const char *name)
+{
+       const char **s;
+       /* Absolute section names */
+       const char *namelist1[] = {
+               "__ftr_fixup",          /* powerpc cpu feature fixup */
+               "__fw_ftr_fixup",       /* powerpc firmware feature fixup */
+               "__param",
+               ".data.rel.ro",         /* used by parisc64 */
+               ".init",
+               ".text.lock",
+               NULL
+       };
+       /* Start of section names */
+       const char *namelist2[] = {
+               ".init.",
+               ".pci_fixup",
+               ".rodata",
+               NULL
+       };
+
+       if (initexit_section_ref_ok(name))
+               return 1;
+
+       for (s = namelist1; *s; s++)
+               if (strcmp(*s, name) == 0)
+                       return 1;
+       for (s = namelist2; *s; s++)
+               if (strncmp(*s, name, strlen(*s)) == 0)
+                       return 1;
+
+       /* If section name ends with ".init" we allow references
+        * as is the case with .initcallN.init, .early_param.init, .taglist.init etc
+        */
+       if (strrcmp(name, ".init") == 0)
+               return 1;
+       return 0;
+}
+
+/*
+ * Functions used only during module exit is marked __exit and is stored in
+ * a .exit.text section. Likewise data is marked __exitdata and stored in
+ * a .exit.data section.
+ * If this section is one of these sections return 1
+ * See include/linux/init.h for the details
+ **/
+static int exit_section(const char *name)
+{
+       if (strcmp(name, ".exit.text") == 0)
+               return 1;
+       if (strcmp(name, ".exit.data") == 0)
+               return 1;
+       return 0;
+
+}
+
+/*
+ * Identify sections from which references to a .exit section is OK.
+ */
+static int exit_section_ref_ok(const char *name)
+{
+       const char **s;
+       /* Absolute section names */
+       const char *namelist1[] = {
+               ".exit.data",
+               ".exit.text",
+               ".exitcall.exit",
+               ".rodata",
+               NULL
+       };
+
+       if (initexit_section_ref_ok(name))
+               return 1;
+
+       for (s = namelist1; *s; s++)
+               if (strcmp(*s, name) == 0)
+                       return 1;
+       return 0;
+}
+
 static void read_symbols(char *modname)
 {
        const char *symname;
        char *version;
+       char *license;
        struct module *mod;
        struct elf_info info = { };
        Elf_Sym *sym;
 
-       parse_elf(&info, modname);
+       if (!parse_elf(&info, modname))
+               return;
 
        mod = new_module(modname);
 
@@ -461,12 +1247,26 @@ static void read_symbols(char *modname)
                mod->skip = 1;
        }
 
+       license = get_modinfo(info.modinfo, info.modinfo_len, "license");
+       while (license) {
+               if (license_is_gpl_compatible(license))
+                       mod->gpl_compatible = 1;
+               else {
+                       mod->gpl_compatible = 0;
+                       break;
+               }
+               license = get_next_modinfo(info.modinfo, info.modinfo_len,
+                                          "license", license);
+       }
+
        for (sym = info.symtab_start; sym < info.symtab_stop; sym++) {
                symname = info.strtab + sym->st_name;
 
                handle_modversions(mod, &info, sym, symname);
                handle_moddevtable(mod, &info, sym, symname);
        }
+       check_sec_ref(mod, modname, &info, init_section, init_section_ref_ok);
+       check_sec_ref(mod, modname, &info, exit_section, exit_section_ref_ok);
 
        version = get_modinfo(info.modinfo, info.modinfo_len, "version");
        if (version)
@@ -498,28 +1298,84 @@ void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf,
        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;
+       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;
+               buf->size += len + SZ;
                buf->p = realloc(buf->p, buf->size);
        }
        strncpy(buf->p + buf->pos, s, len);
        buf->pos += len;
 }
 
+static void check_for_gpl_usage(enum export exp, const char *m, const char *s)
+{
+       const char *e = is_vmlinux(m) ?"":".ko";
+
+       switch (exp) {
+       case export_gpl:
+               fatal("modpost: GPL-incompatible module %s%s "
+                     "uses GPL-only symbol '%s'\n", m, e, s);
+               break;
+       case export_unused_gpl:
+               fatal("modpost: GPL-incompatible module %s%s "
+                     "uses GPL-only symbol marked UNUSED '%s'\n", m, e, s);
+               break;
+       case export_gpl_future:
+               warn("modpost: GPL-incompatible module %s%s "
+                     "uses future GPL-only symbol '%s'\n", m, e, s);
+               break;
+       case export_plain:
+       case export_unused:
+       case export_unknown:
+               /* ignore */
+               break;
+       }
+}
+
+static void check_for_unused(enum export exp, const char* m, const char* s)
+{
+       const char *e = is_vmlinux(m) ?"":".ko";
+
+       switch (exp) {
+       case export_unused:
+       case export_unused_gpl:
+               warn("modpost: module %s%s "
+                     "uses symbol '%s' marked UNUSED\n", m, e, s);
+               break;
+       default:
+               /* ignore */
+               break;
+       }
+}
+
+static void check_exports(struct module *mod)
+{
+       struct symbol *s, *exp;
+
+       for (s = mod->unres; s; s = s->next) {
+               const char *basename;
+               exp = find_symbol(s->name);
+               if (!exp || exp->module == mod)
+                       continue;
+               basename = strrchr(mod->name, '/');
+               if (basename)
+                       basename++;
+               else
+                       basename = mod->name;
+               if (!mod->gpl_compatible)
+                       check_for_gpl_usage(exp->export, basename, exp->name);
+               check_for_unused(exp->export, basename, exp->name);
+        }
+}
+
 /**
  * Header for the generated file
  **/
@@ -540,22 +1396,31 @@ static void add_header(struct buffer *b, struct module *mod)
                buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n"
                              " .exit = cleanup_module,\n"
                              "#endif\n");
+       buf_printf(b, " .arch = MODULE_ARCH_INIT,\n");
        buf_printf(b, "};\n");
 }
 
 /**
  * Record CRCs for unresolved symbols
  **/
-static void add_versions(struct buffer *b, struct module *mod)
+static int add_versions(struct buffer *b, struct module *mod)
 {
        struct symbol *s, *exp;
+       int err = 0;
 
        for (s = mod->unres; s; s = s->next) {
                exp = find_symbol(s->name);
                if (!exp || exp->module == mod) {
-                       if (have_vmlinux && !s->weak)
-                               warn("\"%s\" [%s.ko] undefined!\n",
-                                    s->name, mod->name);
+                       if (have_vmlinux && !s->weak) {
+                               if (warn_unresolved) {
+                                       warn("\"%s\" [%s.ko] undefined!\n",
+                                            s->name, mod->name);
+                               } else {
+                                       merror("\"%s\" [%s.ko] undefined!\n",
+                                                 s->name, mod->name);
+                                       err = 1;
+                               }
+                       }
                        continue;
                }
                s->module = exp->module;
@@ -564,7 +1429,7 @@ static void add_versions(struct buffer *b, struct module *mod)
        }
 
        if (!modversions)
-               return;
+               return err;
 
        buf_printf(b, "\n");
        buf_printf(b, "static const struct modversion_info ____versions[]\n");
@@ -584,6 +1449,8 @@ static void add_versions(struct buffer *b, struct module *mod)
        }
 
        buf_printf(b, "};\n");
+
+       return err;
 }
 
 static void add_depends(struct buffer *b, struct module *mod,
@@ -603,6 +1470,7 @@ static void add_depends(struct buffer *b, struct module *mod,
        buf_printf(b, "__attribute__((section(\".modinfo\"))) =\n");
        buf_printf(b, "\"depends=");
        for (s = mod->unres; s; s = s->next) {
+               const char *p;
                if (!s->module)
                        continue;
 
@@ -610,8 +1478,11 @@ static void add_depends(struct buffer *b, struct module *mod,
                        continue;
 
                s->module->seen = 1;
-               buf_printf(b, "%s%s", first ? "" : ",",
-                          strrchr(s->module->name, '/') + 1);
+               if ((p = strrchr(s->module->name, '/')) != NULL)
+                       p++;
+               else
+                       p = s->module->name;
+               buf_printf(b, "%s%s", first ? "" : ",", p);
                first = 0;
        }
        buf_printf(b, "\";\n");
@@ -670,6 +1541,9 @@ static void write_if_changed(struct buffer *b, const char *fname)
        fclose(file);
 }
 
+/* parse Module.symvers file. line format:
+ * 0x12345678<tab>symbol<tab>module[[<tab>export]<tab>something]
+ **/
 static void read_dump(const char *fname, unsigned int kernel)
 {
        unsigned long size, pos = 0;
@@ -681,7 +1555,7 @@ static void read_dump(const char *fname, unsigned int kernel)
                return;
 
        while ((line = get_next_line(&pos, file, size))) {
-               char *symname, *modname, *d;
+               char *symname, *modname, *d, *export, *end;
                unsigned int crc;
                struct module *mod;
                struct symbol *s;
@@ -692,8 +1566,10 @@ static void read_dump(const char *fname, unsigned int kernel)
                if (!(modname = strchr(symname, '\t')))
                        goto fail;
                *modname++ = '\0';
-               if (strchr(modname, '\t'))
-                       goto fail;
+               if ((export = strchr(modname, '\t')) != NULL)
+                       *export++ = '\0';
+               if (export && ((end = strchr(export, '\t')) != NULL))
+                       *end = '\0';
                crc = strtoul(line, &d, 16);
                if (*symname == '\0' || *modname == '\0' || *d != '\0')
                        goto fail;
@@ -705,9 +1581,10 @@ static void read_dump(const char *fname, unsigned int kernel)
                        mod = new_module(NOFAIL(strdup(modname)));
                        mod->skip = 1;
                }
-               s = sym_add_exported(symname, mod);
-               s->kernel = kernel;
-               sym_update_crc(symname, mod, crc);
+               s = sym_add_exported(symname, mod, export_no(export));
+               s->kernel    = kernel;
+               s->preloaded = 1;
+               sym_update_crc(symname, mod, crc, export_no(export));
        }
        return;
 fail:
@@ -726,7 +1603,7 @@ static int dump_sym(struct symbol *sym)
                return 0;
        return 1;
 }
-               
+
 static void write_dump(const char *fname)
 {
        struct buffer buf = { };
@@ -737,9 +1614,10 @@ static void write_dump(const char *fname)
                symbol = symbolhash[n];
                while (symbol) {
                        if (dump_sym(symbol))
-                               buf_printf(&buf, "0x%08x\t%s\t%s\n",
-                                       symbol->crc, symbol->name, 
-                                       symbol->module->name);
+                               buf_printf(&buf, "0x%08x\t%s\t%s\t%s\n",
+                                       symbol->crc, symbol->name,
+                                       symbol->module->name,
+                                       export_str(symbol->export));
                        symbol = symbol->next;
                }
        }
@@ -754,8 +1632,9 @@ int main(int argc, char **argv)
        char *kernel_read = NULL, *module_read = NULL;
        char *dump_write = NULL;
        int opt;
+       int err;
 
-       while ((opt = getopt(argc, argv, "i:I:mo:a")) != -1) {
+       while ((opt = getopt(argc, argv, "i:I:mo:aw")) != -1) {
                switch(opt) {
                        case 'i':
                                kernel_read = optarg;
@@ -773,6 +1652,9 @@ int main(int argc, char **argv)
                        case 'a':
                                all_versions = 1;
                                break;
+                       case 'w':
+                               warn_unresolved = 1;
+                               break;
                        default:
                                exit(1);
                }
@@ -790,11 +1672,19 @@ int main(int argc, char **argv)
        for (mod = modules; mod; mod = mod->next) {
                if (mod->skip)
                        continue;
+               check_exports(mod);
+       }
+
+       err = 0;
+
+       for (mod = modules; mod; mod = mod->next) {
+               if (mod->skip)
+                       continue;
 
                buf.pos = 0;
 
                add_header(&buf, mod);
-               add_versions(&buf, mod);
+               err |= add_versions(&buf, mod);
                add_depends(&buf, mod, modules);
                add_moddevtable(&buf, mod);
                add_srcversion(&buf, mod);
@@ -806,5 +1696,5 @@ int main(int argc, char **argv)
        if (dump_write)
                write_dump(dump_write);
 
-       return 0;
+       return err;
 }