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authorPeter Zijlstra <peterz@infradead.org>2017-02-08 15:48:01 +0100
committerJessica Yu <jeyu@redhat.com>2017-02-10 19:21:10 -0800
commit5ff22646d246e23bf8056c63bed6aaf9fd22ed12 (patch)
treea7e60df861e3c92e706b06a407c1f01bdbec2be3 /kernel/module.c
parent1f318a8bafcfba9f0d623f4870c4e890fd22e659 (diff)
downloadlinux-5ff22646d246e23bf8056c63bed6aaf9fd22ed12.tar.bz2
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>
Diffstat (limited to 'kernel/module.c')
-rw-r--r--kernel/module.c27
1 files changed, 14 insertions, 13 deletions
diff --git a/kernel/module.c b/kernel/module.c
index 330f64e7e193..32d0d32abbf6 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;
}