livepatch: fix deferred module patching order

When applying multiple patches to a module, if the module is loaded
after the patches are loaded, the patches are applied in reverse order:

  $ insmod patch1.ko
  [   43.172992] livepatch: enabling patch 'patch1'

  $ insmod patch2.ko
  [   46.571563] livepatch: enabling patch 'patch2'

  $ modprobe nfsd
  [   52.888922] livepatch: applying patch 'patch2' to loading module 'nfsd'
  [   52.899847] livepatch: applying patch 'patch1' to loading module 'nfsd'

Fix the loading order by storing the klp_patches list in queue order.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

diff --git a/kernel/livepatch/core.c b/kernel/livepatch/core.c
index ce42d3b930dcbdfe2f0b198bfca5ec4ff841a8c1..3d9c00b5223af9f224d9ea5659de9e4ff1698f6d 100644 (file)
--- a/kernel/livepatch/core.c
+++ b/kernel/livepatch/core.c
@@ -739,7 +739,7 @@ static int klp_init_patch(struct klp_patch *patch)
                        goto free;
        }
 
-       list_add(&patch->list, &klp_patches);
+       list_add_tail(&patch->list, &klp_patches);
 
        mutex_unlock(&klp_mutex);