module: Enhance verify_export_symbols

Make verify_export_symbols check the modules unused, unused_gpl and
gpl_future syms.

Inspired by Jan Beulich's fix, but table-driven.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

diff --git a/kernel/module.c b/kernel/module.c
index ee91893..d2d093e 100644 (file)
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -1400,33 +1400,33 @@ EXPORT_SYMBOL_GPL(__symbol_get);
  */
 static int verify_export_symbols(struct module *mod)
 {
-       const char *name = NULL;
-       unsigned long i, ret = 0;
+       unsigned int i;
        struct module *owner;
-       const unsigned long *crc;
-
-       for (i = 0; i < mod->num_syms; i++)
-               if (!IS_ERR_VALUE(find_symbol(mod->syms[i].name,
-                                             &owner, &crc, true, false))) {
-                       name = mod->syms[i].name;
-                       ret = -ENOEXEC;
-                       goto dup;
-               }
+       const struct kernel_symbol *s;
+       struct {
+               const struct kernel_symbol *sym;
+               unsigned int num;
+       } arr[] = {
+               { mod->syms, mod->num_syms },
+               { mod->gpl_syms, mod->num_gpl_syms },
+               { mod->gpl_future_syms, mod->num_gpl_future_syms },
+               { mod->unused_syms, mod->num_unused_syms },
+               { mod->unused_gpl_syms, mod->num_unused_gpl_syms },
+       };
 
-       for (i = 0; i < mod->num_gpl_syms; i++)
-               if (!IS_ERR_VALUE(find_symbol(mod->gpl_syms[i].name,
-                                             &owner, &crc, true, false))) {
-                       name = mod->gpl_syms[i].name;
-                       ret = -ENOEXEC;
-                       goto dup;
+       for (i = 0; i < ARRAY_SIZE(arr); i++) {
+               for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) {
+                       if (!IS_ERR_VALUE(find_symbol(s->name, &owner,
+                                                     NULL, true, false))) {
+                               printk(KERN_ERR
+                                      "%s: exports duplicate symbol %s"
+                                      " (owned by %s)\n",
+                                      mod->name, s->name, module_name(owner));
+                               return -ENOEXEC;
+                       }
                }
-
-dup:
-       if (ret)
-               printk(KERN_ERR "%s: exports duplicate symbol %s (owned by %s)\n",
-                       mod->name, name, module_name(owner));
-
-       return ret;
+       }
+       return 0;
 }
 
 /* Change all symbols so that st_value encodes the pointer directly. */