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>
This commit is contained in:
Peter Zijlstra 2017-02-08 15:48:01 +01:00 committed by Jessica Yu
parent 1f318a8baf
commit 5ff22646d2
1 changed files with 14 additions and 13 deletions

View File

@ -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;
}