for disable_patch:
The patch is unallowed to be disabled if one patch after has
dependencies with it and has been enabled.
for enable_patch:
The patch is unallowed to be enabled if one patch before has
dependencies with it and has been disabled.
Signed-off-by: Li Bin <huawei.li...@huawei.com>
---
kernel/livepatch/core.c | 60 +++++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 60 insertions(+), 0 deletions(-)
diff --git a/kernel/livepatch/core.c b/kernel/livepatch/core.c
index 7861ed2..a12a31c 100644
--- a/kernel/livepatch/core.c
+++ b/kernel/livepatch/core.c
@@ -114,6 +114,21 @@ static bool klp_is_patch_registered(struct klp_patch
*patch)
return false;
}
+static bool klp_func_in_patch(struct klp_func *kfunc, struct klp_patch *patch)
+{
+ struct klp_object *obj;
+ struct klp_func *func;
+
+ for (obj = patch->objs; obj->funcs; obj++) {
+ for (func = obj->funcs; func->old_name; func++) {
+ if (kfunc->old_addr == func->old_addr) {
+ return true;
+ }
+ }
+ }
+ return false;
+}
+
static bool klp_initialized(void)
{
return klp_root_kobj;
@@ -466,8 +481,31 @@ unregister:
static int __klp_disable_patch(struct klp_patch *patch)
{
struct klp_object *obj;
+ struct klp_patch *temp;
+ struct klp_func *func;
int ret;
+ /*
+ * the patch is unallowed to be disabled if one patch
+ * after has dependencies with it and has been enabled.
+ */
+ for (temp = list_next_entry(patch, list);
+ &temp->list != &klp_patches;
+ temp = list_next_entry(temp, list)) {
+ if (temp->state != KLP_ENABLED)
+ continue;
+
+ for (obj = patch->objs; obj->funcs; obj++) {
+ for (func = obj->funcs; func->old_name; func++) {
+ if (klp_func_in_patch(func, temp)) {
+ pr_err("this patch depends on '%s',
please disable it firstly\n",
+ temp->mod->name);
+ return -EBUSY;
+ }
+ }
+ }
+ }
+
pr_notice("disabling patch '%s'\n", patch->mod->name);
for (obj = patch->objs; obj->funcs; obj++) {
@@ -519,11 +557,33 @@ EXPORT_SYMBOL_GPL(klp_disable_patch);
static int __klp_enable_patch(struct klp_patch *patch)
{
struct klp_object *obj;
+ struct klp_patch *temp;
+ struct klp_func *func;
int ret;
if (WARN_ON(patch->state != KLP_DISABLED))
return -EINVAL;
+ /*
+ * the patch is unallowed to be enabled if one patch
+ * before has dependencies with it and has been disabled.
+ */
+ for (temp = list_first_entry(&klp_patches, struct klp_patch, list);
+ temp != patch; temp = list_next_entry(temp, list)) {
+ if (temp->state != KLP_DISABLED)
+ continue;
+
+ for (obj = patch->objs; obj->funcs; obj++) {
+ for (func = obj->funcs; func->old_name; func++) {
+ if (klp_func_in_patch(func, temp)) {
+ pr_err("this patch depends on '%s',
please enable it firstly\n",
+ temp->mod->name);
+ return -EBUSY;
+ }
+ }
+ }
+ }
+
pr_notice_once("tainting kernel with TAINT_LIVEPATCH\n");
add_taint(TAINT_LIVEPATCH, LOCKDEP_STILL_OK);
--
1.7.1
--
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