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Message-ID: <20250115082431.5550-20-pmladek@suse.com>
Date: Wed, 15 Jan 2025 09:24:31 +0100
From: Petr Mladek <pmladek@...e.com>
To: Josh Poimboeuf <jpoimboe@...nel.org>,
Miroslav Benes <mbenes@...e.cz>
Cc: Joe Lawrence <joe.lawrence@...hat.com>,
Nicolai Stange <nstange@...e.de>,
live-patching@...r.kernel.org,
linux-kernel@...r.kernel.org,
Petr Mladek <pmladek@...e.com>
Subject: [PATCH v1 19/19] livepatch: Remove obsolete per-object callbacks
This commit removes the obsolete per-object callbacks from the livepatch
framework. All selftests have been migrated to the new per-state
callbacks, making the per-object callbacks redundant.
Instead, use the new per-state callbacks. They offer improved semantics
by associating callbacks and shadow variables with a specific state,
enabling better lifetime management of changes.
Signed-off-by: Petr Mladek <pmladek@...e.com>
---
include/linux/livepatch.h | 26 --------------------------
kernel/livepatch/core.c | 29 -----------------------------
kernel/livepatch/core.h | 33 ---------------------------------
kernel/livepatch/transition.c | 9 ---------
4 files changed, 97 deletions(-)
diff --git a/include/linux/livepatch.h b/include/linux/livepatch.h
index d02d7a616338..428300181af3 100644
--- a/include/linux/livepatch.h
+++ b/include/linux/livepatch.h
@@ -77,35 +77,10 @@ struct klp_func {
bool transition;
};
-struct klp_object;
-
-/**
- * struct klp_callbacks - pre/post live-(un)patch callback structure
- * @pre_patch: executed before code patching
- * @post_patch: executed after code patching
- * @pre_unpatch: executed before code unpatching
- * @post_unpatch: executed after code unpatching
- * @post_unpatch_enabled: flag indicating if post-unpatch callback
- * should run
- *
- * All callbacks are optional. Only the pre-patch callback, if provided,
- * will be unconditionally executed. If the parent klp_object fails to
- * patch for any reason, including a non-zero error status returned from
- * the pre-patch callback, no further callbacks will be executed.
- */
-struct klp_callbacks {
- int (*pre_patch)(struct klp_object *obj);
- void (*post_patch)(struct klp_object *obj);
- void (*pre_unpatch)(struct klp_object *obj);
- void (*post_unpatch)(struct klp_object *obj);
- bool post_unpatch_enabled;
-};
-
/**
* struct klp_object - kernel object structure for live patching
* @name: module name (or NULL for vmlinux)
* @funcs: function entries for functions to be patched in the object
- * @callbacks: functions to be executed pre/post (un)patching
* @kobj: kobject for sysfs resources
* @func_list: dynamic list of the function entries
* @node: list node for klp_patch obj_list
@@ -118,7 +93,6 @@ struct klp_object {
/* external */
const char *name;
struct klp_func *funcs;
- struct klp_callbacks callbacks;
/* internal */
struct kobject kobj;
diff --git a/kernel/livepatch/core.c b/kernel/livepatch/core.c
index 4d244eef0e53..3d6b8edb3e2b 100644
--- a/kernel/livepatch/core.c
+++ b/kernel/livepatch/core.c
@@ -983,8 +983,6 @@ static int klp_init_patch(struct klp_patch *patch)
static int __klp_disable_patch(struct klp_patch *patch)
{
- struct klp_object *obj;
-
if (WARN_ON(!patch->enabled))
return -EINVAL;
@@ -995,10 +993,6 @@ static int __klp_disable_patch(struct klp_patch *patch)
klp_states_pre_unpatch(patch);
- klp_for_each_object(patch, obj)
- if (obj->patched)
- klp_pre_unpatch_callback(obj);
-
/*
* Enforce the order of the func->transition writes in
* klp_init_transition() and the TIF_PATCH_PENDING writes in
@@ -1050,13 +1044,6 @@ static int __klp_enable_patch(struct klp_patch *patch)
if (!klp_is_object_loaded(obj))
continue;
- ret = klp_pre_patch_callback(obj);
- if (ret) {
- pr_warn("pre-patch callback failed for object '%s'\n",
- klp_is_module(obj) ? obj->name : "vmlinux");
- goto err;
- }
-
ret = klp_patch_object(obj);
if (ret) {
pr_warn("failed to patch object '%s'\n",
@@ -1226,14 +1213,10 @@ static void klp_cleanup_module_patches_limited(struct module *mod,
if (!klp_is_module(obj) || strcmp(obj->name, mod->name))
continue;
- if (patch != klp_transition_patch)
- klp_pre_unpatch_callback(obj);
-
pr_notice("reverting patch '%s' on unloading module '%s'\n",
patch->mod->name, obj->mod->name);
klp_unpatch_object(obj);
- klp_post_unpatch_callback(obj);
klp_clear_object_relocs(patch, obj);
klp_free_object_loaded(obj);
break;
@@ -1280,25 +1263,13 @@ int klp_module_coming(struct module *mod)
pr_notice("applying patch '%s' to loading module '%s'\n",
patch->mod->name, obj->mod->name);
- ret = klp_pre_patch_callback(obj);
- if (ret) {
- pr_warn("pre-patch callback failed for object '%s'\n",
- obj->name);
- goto err;
- }
-
ret = klp_patch_object(obj);
if (ret) {
pr_warn("failed to apply patch '%s' to module '%s' (%d)\n",
patch->mod->name, obj->mod->name, ret);
-
- klp_post_unpatch_callback(obj);
goto err;
}
- if (patch != klp_transition_patch)
- klp_post_patch_callback(obj);
-
break;
}
}
diff --git a/kernel/livepatch/core.h b/kernel/livepatch/core.h
index 38209c7361b6..02b8364f6779 100644
--- a/kernel/livepatch/core.h
+++ b/kernel/livepatch/core.h
@@ -23,37 +23,4 @@ static inline bool klp_is_object_loaded(struct klp_object *obj)
return !obj->name || obj->mod;
}
-static inline int klp_pre_patch_callback(struct klp_object *obj)
-{
- int ret = 0;
-
- if (obj->callbacks.pre_patch)
- ret = (*obj->callbacks.pre_patch)(obj);
-
- obj->callbacks.post_unpatch_enabled = !ret;
-
- return ret;
-}
-
-static inline void klp_post_patch_callback(struct klp_object *obj)
-{
- if (obj->callbacks.post_patch)
- (*obj->callbacks.post_patch)(obj);
-}
-
-static inline void klp_pre_unpatch_callback(struct klp_object *obj)
-{
- if (obj->callbacks.pre_unpatch)
- (*obj->callbacks.pre_unpatch)(obj);
-}
-
-static inline void klp_post_unpatch_callback(struct klp_object *obj)
-{
- if (obj->callbacks.post_unpatch_enabled &&
- obj->callbacks.post_unpatch)
- (*obj->callbacks.post_unpatch)(obj);
-
- obj->callbacks.post_unpatch_enabled = false;
-}
-
#endif /* _LIVEPATCH_CORE_H */
diff --git a/kernel/livepatch/transition.c b/kernel/livepatch/transition.c
index f3dce9fe9897..c5e9dcf3e453 100644
--- a/kernel/livepatch/transition.c
+++ b/kernel/livepatch/transition.c
@@ -155,15 +155,6 @@ static void klp_complete_transition(void)
klp_states_post_unpatch(klp_transition_patch);
}
- klp_for_each_object(klp_transition_patch, obj) {
- if (!klp_is_object_loaded(obj))
- continue;
- if (klp_target_state == KLP_TRANSITION_PATCHED)
- klp_post_patch_callback(obj);
- else if (klp_target_state == KLP_TRANSITION_UNPATCHED)
- klp_post_unpatch_callback(obj);
- }
-
pr_notice("'%s': %s complete\n", klp_transition_patch->mod->name,
klp_target_state == KLP_TRANSITION_PATCHED ? "patching" : "unpatching");
--
2.47.1
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