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-rw-r--r--kernel/module.c26
1 files changed, 10 insertions, 16 deletions
diff --git a/kernel/module.c b/kernel/module.c
index 2845004..f99558e 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);