1 files changed, 10 insertions, 16 deletions

diff --git a/kernel/module.c b/kernel/module.c
index 28450047852a..f99558e1945a 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -1571,6 +1571,8 @@ EXPORT_SYMBOL_GPL(__symbol_get);
 /*
  * Ensure that an exported symbol [global namespace] does not already exist
  * in the kernel or in some other module's exported symbol table.
+ *
+ * You must hold the module_mutex.
  */
 static int verify_export_symbols(struct module *mod)
 {
@@ -1592,14 +1594,7 @@ static int verify_export_symbols(struct module *mod)
 
         for (i = 0; i < ARRAY_SIZE(arr); i++) {
                 for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) {
-                        const struct kernel_symbol *sym;
-
-                        /* Stopping preemption makes find_symbol safe. */
-                        preempt_disable();
-                        sym = find_symbol(s->name, &owner, NULL, true, false);
-                        preempt_enable();
-
-                        if (sym) {
+                        if (find_symbol(s->name, &owner, NULL, true, false)) {
                                 printk(KERN_ERR
                                        "%s: exports duplicate symbol %s"
                                        " (owned by %s)\n",
@@ -2440,11 +2435,6 @@ static noinline struct module *load_module(void __user *umod,
                         goto cleanup;
         }
 
-        /* Find duplicate symbols */
-        err = verify_export_symbols(mod);
-        if (err < 0)
-                goto cleanup;
-
         /* Set up and sort exception table */
         mod->extable = section_objs(hdr, sechdrs, secstrings, "__ex_table",
                                     sizeof(*mod->extable), &mod->num_exentries);
@@ -2506,10 +2496,14 @@ static noinline struct module *load_module(void __user *umod,
         mutex_lock(&module_mutex);
         if (find_module(mod->name)) {
                 err = -EEXIST;
-                /* This will also unlock the mutex */
-                goto already_exists;
+                goto unlock;
         }
 
+        /* Find duplicate symbols */
+        err = verify_export_symbols(mod);
+        if (err < 0)
+                goto unlock;
+
         list_add_rcu(&mod->list, &modules);
         mutex_unlock(&module_mutex);
 
@@ -2536,7 +2530,7 @@ static noinline struct module *load_module(void __user *umod,
         mutex_lock(&module_mutex);
         /* Unlink carefully: kallsyms could be walking list. */
         list_del_rcu(&mod->list);
- already_exists:
+ unlock:
         mutex_unlock(&module_mutex);
         synchronize_sched();
         module_arch_cleanup(mod);