[RFC kgr on klp 2/9] livepatch: introduce patch/func-walking helpers

From: Jiri Slaby
Date: Mon May 04 2015 - 07:40:49 EST


klp_for_each_object and klp_for_each_func are now used all over the
code. One need not think what is the proper condition to check in the
for loop now.

Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
---
include/linux/livepatch.h | 6 ++++++
kernel/livepatch/core.c | 18 +++++++++---------
2 files changed, 15 insertions(+), 9 deletions(-)

diff --git a/include/linux/livepatch.h b/include/linux/livepatch.h
index fe45f2f02c8d..31db7a05dd36 100644
--- a/include/linux/livepatch.h
+++ b/include/linux/livepatch.h
@@ -123,6 +123,12 @@ struct klp_patch {
enum klp_state state;
};

+#define klp_for_each_object(patch, obj) \
+ for (obj = patch->objs; obj->funcs; obj++)
+
+#define klp_for_each_func(obj, func) \
+ for (func = obj->funcs; func->old_name; func++)
+
int klp_register_patch(struct klp_patch *);
int klp_unregister_patch(struct klp_patch *);
int klp_enable_patch(struct klp_patch *);
diff --git a/kernel/livepatch/core.c b/kernel/livepatch/core.c
index e163faaef5e9..2da42be84452 100644
--- a/kernel/livepatch/core.c
+++ b/kernel/livepatch/core.c
@@ -422,7 +422,7 @@ static void klp_disable_object(struct klp_object *obj)
{
struct klp_func *func;

- for (func = obj->funcs; func->old_name; func++)
+ klp_for_each_func(obj, func)
if (func->state == KLP_ENABLED)
klp_disable_func(func);

@@ -440,7 +440,7 @@ static int klp_enable_object(struct klp_object *obj)
if (WARN_ON(!klp_is_object_loaded(obj)))
return -EINVAL;

- for (func = obj->funcs; func->old_name; func++) {
+ klp_for_each_func(obj, func) {
ret = klp_enable_func(func);
if (ret) {
klp_disable_object(obj);
@@ -463,7 +463,7 @@ static int __klp_disable_patch(struct klp_patch *patch)

pr_notice("disabling patch '%s'\n", patch->mod->name);

- for (obj = patch->objs; obj->funcs; obj++) {
+ klp_for_each_object(patch, obj) {
if (obj->state == KLP_ENABLED)
klp_disable_object(obj);
}
@@ -523,7 +523,7 @@ static int __klp_enable_patch(struct klp_patch *patch)

pr_notice("enabling patch '%s'\n", patch->mod->name);

- for (obj = patch->objs; obj->funcs; obj++) {
+ klp_for_each_object(patch, obj) {
if (!klp_is_object_loaded(obj))
continue;

@@ -689,7 +689,7 @@ static void klp_free_object_loaded(struct klp_object *obj)

obj->mod = NULL;

- for (func = obj->funcs; func->old_name; func++)
+ klp_for_each_func(obj, func)
func->old_addr = 0;
}

@@ -738,7 +738,7 @@ static int klp_init_object_loaded(struct klp_patch *patch,
return ret;
}

- for (func = obj->funcs; func->old_name; func++) {
+ klp_for_each_func(obj, func) {
ret = klp_find_verify_func_addr(obj, func);
if (ret)
return ret;
@@ -767,7 +767,7 @@ static int klp_init_object(struct klp_patch *patch, struct klp_object *obj)
if (ret)
return ret;

- for (func = obj->funcs; func->old_name; func++) {
+ klp_for_each_func(obj, func) {
ret = klp_init_func(obj, func);
if (ret)
goto free;
@@ -804,7 +804,7 @@ static int klp_init_patch(struct klp_patch *patch)
if (ret)
goto unlock;

- for (obj = patch->objs; obj->funcs; obj++) {
+ klp_for_each_object(patch, obj) {
ret = klp_init_object(patch, obj);
if (ret)
goto free;
@@ -959,7 +959,7 @@ static int klp_module_notify(struct notifier_block *nb, unsigned long action,
mod->klp_alive = false;

list_for_each_entry(patch, &klp_patches, list) {
- for (obj = patch->objs; obj->funcs; obj++) {
+ klp_for_each_object(patch, obj) {
if (!klp_is_module(obj) || strcmp(obj->name, mod->name))
continue;

--
2.3.5

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