kbuild: check license compatibility when building modules

[linux-2.6-block.git] / scripts / mod / modpost.c

diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index ba2e4fc2af20e2b816c3ddfd6bc8e491c304eadc..baa4d83d29a80cf5126a983a7ac3eb8cf7423ac8 100644 (file)
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -13,6 +13,7 @@
 
 #include <ctype.h>
 #include "modpost.h"
+#include "../../include/linux/license.h"
 
 /* Are we using CONFIG_MODVERSIONS? */
 int modversions = 0;
@@ -99,6 +100,7 @@ static struct module *new_module(char *modname)
 
        /* add to list */
        mod->name = p;
+       mod->gpl_compatible = -1;
        mod->next = modules;
        modules = mod;
 
@@ -493,13 +495,18 @@ 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;
@@ -507,6 +514,13 @@ 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
@@ -981,6 +995,7 @@ static void read_symbols(char *modname)
 {
        const char *symname;
        char *version;
+       char *license;
        struct module *mod;
        struct elf_info info = { };
        Elf_Sym *sym;
@@ -996,6 +1011,18 @@ 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;
 
@@ -1052,6 +1079,40 @@ void buf_write(struct buffer *buf, const char *s, int len)
        buf->pos += len;
 }
 
+void check_license(struct module *mod)
+{
+       struct symbol *s, *exp;
+
+       for (s = mod->unres; s; s = s->next) {
+               if (mod->gpl_compatible == 1) {
+                       /* GPL-compatible modules may use all symbols */
+                       continue;
+               }
+               exp = find_symbol(s->name);
+               if (!exp || exp->module == mod)
+                       continue;
+               const char *basename = strrchr(mod->name, '/');
+               if (basename)
+                       basename++;
+               switch (exp->export) {
+                       case export_gpl:
+                               fatal("modpost: GPL-incompatible module %s "
+                                     "uses GPL-only symbol '%s'\n",
+                                basename ? basename : mod->name,
+                               exp->name);
+                               break;
+                       case export_gpl_future:
+                               warn("modpost: GPL-incompatible module %s "
+                                     "uses future GPL-only symbol '%s'\n",
+                                     basename ? basename : mod->name,
+                                     exp->name);
+                               break;
+                       case export_plain: /* ignore */ break;
+                       case export_unknown: /* ignore */ break;
+               }
+        }
+}
+
 /**
  * Header for the generated file
  **/
@@ -1325,6 +1386,12 @@ int main(int argc, char **argv)
                read_symbols(argv[optind++]);
        }
 
+       for (mod = modules; mod; mod = mod->next) {
+               if (mod->skip)
+                       continue;
+               check_license(mod);
+       }
+
        for (mod = modules; mod; mod = mod->next) {
                if (mod->skip)
                        continue;