module: Optimize search_module_extables()
While looking through the __ex_table stuff I found that we do a linear
lookup of the module. Also fix up a comment.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Jessica Yu <jeyu@redhat.com>
diff --git a/kernel/module.c b/kernel/module.c
index 330f64e..32d0d32 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -4170,22 +4170,23 @@ const struct exception_table_entry *search_module_extables(unsigned long addr)
struct module *mod;
preempt_disable();
- list_for_each_entry_rcu(mod, &modules, list) {
- if (mod->state == MODULE_STATE_UNFORMED)
- continue;
- if (mod->num_exentries == 0)
- continue;
+ mod = __module_address(addr);
+ if (!mod)
+ goto out;
- e = search_extable(mod->extable,
- mod->extable + mod->num_exentries - 1,
- addr);
- if (e)
- break;
- }
+ if (!mod->num_exentries)
+ goto out;
+
+ e = search_extable(mod->extable,
+ mod->extable + mod->num_exentries - 1,
+ addr);
+out:
preempt_enable();
- /* Now, if we found one, we are running inside it now, hence
- we cannot unload the module, hence no refcnt needed. */
+ /*
+ * Now, if we found one, we are running inside it now, hence
+ * we cannot unload the module, hence no refcnt needed.
+ */
return e;
}