Merge tag 'livepatching-for-5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/livepatching/livepatching
Pull livepatching updates from Petr Mladek:
- Correctly handle kobjects when a livepatch init fails
- Avoid CPU hogging when searching for many livepatched symbols
- Add livepatch API page into documentation
* tag 'livepatching-for-5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/livepatching/livepatching:
livepatch: Avoid CPU hogging with cond_resched
livepatch: Fix missing unlock on error in klp_enable_patch()
livepatch: Fix kobject refcount bug on klp_init_patch_early failure path
Documentation: livepatch: Add livepatch API page
diff --git a/Documentation/livepatch/api.rst b/Documentation/livepatch/api.rst
new file mode 100644
index 0000000..78944b6
--- /dev/null
+++ b/Documentation/livepatch/api.rst
@@ -0,0 +1,30 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+=================
+Livepatching APIs
+=================
+
+Livepatch Enablement
+====================
+
+.. kernel-doc:: kernel/livepatch/core.c
+ :export:
+
+
+Shadow Variables
+================
+
+.. kernel-doc:: kernel/livepatch/shadow.c
+ :export:
+
+System State Changes
+====================
+
+.. kernel-doc:: kernel/livepatch/state.c
+ :export:
+
+Object Types
+============
+
+.. kernel-doc:: include/linux/livepatch.h
+ :identifiers: klp_patch klp_object klp_func klp_callbacks klp_state
diff --git a/Documentation/livepatch/index.rst b/Documentation/livepatch/index.rst
index 43cce5f..cebf1c7 100644
--- a/Documentation/livepatch/index.rst
+++ b/Documentation/livepatch/index.rst
@@ -14,6 +14,7 @@
shadow-vars
system-state
reliable-stacktrace
+ api
.. only:: subproject and html
diff --git a/Documentation/livepatch/shadow-vars.rst b/Documentation/livepatch/shadow-vars.rst
index 6a7d43a..7a7098b 100644
--- a/Documentation/livepatch/shadow-vars.rst
+++ b/Documentation/livepatch/shadow-vars.rst
@@ -82,8 +82,8 @@
- call destructor function if defined
- free shadow variable
-* klp_shadow_free_all() - detach and free all <*, id> shadow variables
- - find and remove any <*, id> references from global hashtable
+* klp_shadow_free_all() - detach and free all <_, id> shadow variables
+ - find and remove any <_, id> references from global hashtable
- if found
diff --git a/Documentation/livepatch/system-state.rst b/Documentation/livepatch/system-state.rst
index c6d127c..7a3935f 100644
--- a/Documentation/livepatch/system-state.rst
+++ b/Documentation/livepatch/system-state.rst
@@ -52,12 +52,12 @@
The state can be manipulated using two functions:
- - *klp_get_state(patch, id)*
+ - klp_get_state()
- Get struct klp_state associated with the given livepatch
and state id.
- - *klp_get_prev_state(id)*
+ - klp_get_prev_state()
- Get struct klp_state associated with the given feature id and
already installed livepatches.
diff --git a/kernel/kallsyms.c b/kernel/kallsyms.c
index 3011bc33..951c932 100644
--- a/kernel/kallsyms.c
+++ b/kernel/kallsyms.c
@@ -243,6 +243,7 @@ int kallsyms_on_each_symbol(int (*fn)(void *, const char *, struct module *,
ret = fn(data, namebuf, NULL, kallsyms_sym_address(i));
if (ret != 0)
return ret;
+ cond_resched();
}
return 0;
}
diff --git a/kernel/livepatch/core.c b/kernel/livepatch/core.c
index 335d988..585494e 100644
--- a/kernel/livepatch/core.c
+++ b/kernel/livepatch/core.c
@@ -862,14 +862,11 @@ static void klp_init_object_early(struct klp_patch *patch,
list_add_tail(&obj->node, &patch->obj_list);
}
-static int klp_init_patch_early(struct klp_patch *patch)
+static void klp_init_patch_early(struct klp_patch *patch)
{
struct klp_object *obj;
struct klp_func *func;
- if (!patch->objs)
- return -EINVAL;
-
INIT_LIST_HEAD(&patch->list);
INIT_LIST_HEAD(&patch->obj_list);
kobject_init(&patch->kobj, &klp_ktype_patch);
@@ -879,20 +876,12 @@ static int klp_init_patch_early(struct klp_patch *patch)
init_completion(&patch->finish);
klp_for_each_object_static(patch, obj) {
- if (!obj->funcs)
- return -EINVAL;
-
klp_init_object_early(patch, obj);
klp_for_each_func_static(obj, func) {
klp_init_func_early(obj, func);
}
}
-
- if (!try_module_get(patch->mod))
- return -ENODEV;
-
- return 0;
}
static int klp_init_patch(struct klp_patch *patch)
@@ -1024,10 +1013,17 @@ static int __klp_enable_patch(struct klp_patch *patch)
int klp_enable_patch(struct klp_patch *patch)
{
int ret;
+ struct klp_object *obj;
- if (!patch || !patch->mod)
+ if (!patch || !patch->mod || !patch->objs)
return -EINVAL;
+ klp_for_each_object_static(patch, obj) {
+ if (!obj->funcs)
+ return -EINVAL;
+ }
+
+
if (!is_livepatch_module(patch->mod)) {
pr_err("module %s is not marked as a livepatch module\n",
patch->mod->name);
@@ -1051,12 +1047,13 @@ int klp_enable_patch(struct klp_patch *patch)
return -EINVAL;
}
- ret = klp_init_patch_early(patch);
- if (ret) {
+ if (!try_module_get(patch->mod)) {
mutex_unlock(&klp_mutex);
- return ret;
+ return -ENODEV;
}
+ klp_init_patch_early(patch);
+
ret = klp_init_patch(patch);
if (ret)
goto err;
diff --git a/kernel/livepatch/shadow.c b/kernel/livepatch/shadow.c
index e5c9fb2..c2e724d 100644
--- a/kernel/livepatch/shadow.c
+++ b/kernel/livepatch/shadow.c
@@ -272,12 +272,12 @@ void klp_shadow_free(void *obj, unsigned long id, klp_shadow_dtor_t dtor)
EXPORT_SYMBOL_GPL(klp_shadow_free);
/**
- * klp_shadow_free_all() - detach and free all <*, id> shadow variables
+ * klp_shadow_free_all() - detach and free all <_, id> shadow variables
* @id: data identifier
* @dtor: custom callback that can be used to unregister the variable
* and/or free data that the shadow variable points to (optional)
*
- * This function releases the memory for all <*, id> shadow variable
+ * This function releases the memory for all <_, id> shadow variable
* instances, callers should stop referencing them accordingly.
*/
void klp_shadow_free_all(unsigned long id, klp_shadow_dtor_t dtor)
@@ -288,7 +288,7 @@ void klp_shadow_free_all(unsigned long id, klp_shadow_dtor_t dtor)
spin_lock_irqsave(&klp_shadow_lock, flags);
- /* Delete all <*, id> from hash */
+ /* Delete all <_, id> from hash */
hash_for_each(klp_shadow_hash, i, shadow, node) {
if (klp_shadow_match(shadow, shadow->obj, id))
klp_shadow_free_struct(shadow, dtor);
diff --git a/kernel/module.c b/kernel/module.c
index 84a9141..24fc305 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -4499,6 +4499,8 @@ int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
mod, kallsyms_symbol_value(sym));
if (ret != 0)
goto out;
+
+ cond_resched();
}
}
out:
