[PATCH v9 1/9] livepatch: Use lists to manage patches, objects and functions

[Petr Mladek]

From: Jason Baron 

Currently klp_patch contains a pointer to a statically allocated array of
struct klp_object and struct klp_objects contains a pointer to a statically
allocated array of klp_func. In order to allow for the dynamic allocation
of objects and functions, link klp_patch, klp_object, and klp_func together
via linked lists. This allows us to more easily allocate new objects and
functions, while having the iterator be a simple linked list walk.

The static structures are added to the lists early. It allows to add
the dynamically allocated objects before klp_init_object() and
klp_init_func() calls. Therefore it reduces the further changes
to the code.

Also klp_init_*_list() functions are split because they will
be used when adding the dynamically allocated structures.

This patch does not change the existing behavior.

Signed-off-by: Jason Baron 
[pmla...@suse.com: Initialize lists before init calls]
Signed-off-by: Petr Mladek 
Cc: Josh Poimboeuf 
Cc: Jessica Yu 
Cc: Jiri Kosina 
Acked-by: Miroslav Benes 
---
 include/linux/livepatch.h | 19 +--
 kernel/livepatch/core.c   | 27 +++
 2 files changed, 44 insertions(+), 2 deletions(-)

diff --git a/include/linux/livepatch.h b/include/linux/livepatch.h
index 4754f01c1abb..e5db2ba7e2a5 100644
--- a/include/linux/livepatch.h
+++ b/include/linux/livepatch.h
@@ -24,6 +24,7 @@
 #include 
 #include 
 #include 
+#include 
 
 #if IS_ENABLED(CONFIG_LIVEPATCH)
 
@@ -43,6 +44,7 @@
  * @old_addr:  the address of the function being patched
  * @kobj:  kobject for sysfs resources
  * @stack_node:list node for klp_ops func_stack list
+ * @func_entry:links struct klp_func to struct klp_object
  * @old_size:  size of the old function
  * @new_size:  size of the new function
  * @patched:   the func has been added to the klp_ops list
@@ -80,6 +82,7 @@ struct klp_func {
unsigned long old_addr;
struct kobject kobj;
struct list_head stack_node;
+   struct list_head func_entry;
unsigned long old_size, new_size;
bool patched;
bool transition;
@@ -117,6 +120,8 @@ struct klp_callbacks {
  * @kobj:  kobject for sysfs resources
  * @mod:   kernel module associated with the patched object
  * (NULL for vmlinux)
+ * @func_list: head of list for struct klp_func
+ * @obj_entry: links struct klp_object to struct klp_patch
  * @patched:   the object's funcs have been added to the klp_ops list
  */
 struct klp_object {
@@ -127,6 +132,8 @@ struct klp_object {
 
/* internal */
struct kobject kobj;
+   struct list_head func_list;
+   struct list_head obj_entry;
struct module *mod;
bool patched;
 };
@@ -137,6 +144,7 @@ struct klp_object {
  * @objs:  object entries for kernel objects to be patched
  * @list:  list node for global list of registered patches
  * @kobj:  kobject for sysfs resources
+ * @obj_list:  head of list for struct klp_object
  * @enabled:   the patch is enabled (but operation may be incomplete)
  * @finish:for waiting till it is safe to remove the patch module
  */
@@ -148,18 +156,25 @@ struct klp_patch {
/* internal */
struct list_head list;
struct kobject kobj;
+   struct list_head obj_list;
bool enabled;
struct completion finish;
 };
 
-#define klp_for_each_object(patch, obj) \
+#define klp_for_each_object_static(patch, obj) \
for (obj = patch->objs; obj->funcs || obj->name; obj++)
 
-#define klp_for_each_func(obj, func) \
+#define klp_for_each_object(patch, obj)\
+   list_for_each_entry(obj, >obj_list, obj_entry)
+
+#define klp_for_each_func_static(obj, func) \
for (func = obj->funcs; \
 func->old_name || func->new_func || func->old_sympos; \
 func++)
 
+#define klp_for_each_func(obj, func)   \
+   list_for_each_entry(func, >func_list, func_entry)
+
 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 3a4656fb7047..1d525f4a270a 100644
--- a/kernel/livepatch/core.c
+++ b/kernel/livepatch/core.c
@@ -49,6 +49,32 @@ static LIST_HEAD(klp_patches);
 
 static struct kobject *klp_root_kobj;
 
+static void klp_init_func_list(struct klp_object *obj, struct klp_func *func)
+{
+   list_add(>func_entry, >func_list);
+}
+
+static void klp_init_object_list(struct klp_patch *patch,
+struct klp_object *obj)
+{
+   struct klp_func *func;
+
+   list_add(>obj_entry, >obj_list);
+
+   INIT_LIST_HEAD(>func_list);
+   klp_for_each_func_static(obj, func)
+   klp_init_func_list(obj, func);
+}
+
+static void klp_init_patch_list(struct klp_patch *patch)
+{
+   struct 

[PATCH v9 1/9] livepatch: Use lists to manage patches, objects and functions

[Petr Mladek]

From: Jason Baron 

Currently klp_patch contains a pointer to a statically allocated array of
struct klp_object and struct klp_objects contains a pointer to a statically
allocated array of klp_func. In order to allow for the dynamic allocation
of objects and functions, link klp_patch, klp_object, and klp_func together
via linked lists. This allows us to more easily allocate new objects and
functions, while having the iterator be a simple linked list walk.

The static structures are added to the lists early. It allows to add
the dynamically allocated objects before klp_init_object() and
klp_init_func() calls. Therefore it reduces the further changes
to the code.

Also klp_init_*_list() functions are split because they will
be used when adding the dynamically allocated structures.

This patch does not change the existing behavior.

Signed-off-by: Jason Baron 
[pmla...@suse.com: Initialize lists before init calls]
Signed-off-by: Petr Mladek 
Cc: Josh Poimboeuf 
Cc: Jessica Yu 
Cc: Jiri Kosina 
Acked-by: Miroslav Benes 
---
 include/linux/livepatch.h | 19 +--
 kernel/livepatch/core.c   | 27 +++
 2 files changed, 44 insertions(+), 2 deletions(-)

diff --git a/include/linux/livepatch.h b/include/linux/livepatch.h
index 4754f01c1abb..e5db2ba7e2a5 100644
--- a/include/linux/livepatch.h
+++ b/include/linux/livepatch.h
@@ -24,6 +24,7 @@
 #include 
 #include 
 #include 
+#include 
 
 #if IS_ENABLED(CONFIG_LIVEPATCH)
 
@@ -43,6 +44,7 @@
  * @old_addr:  the address of the function being patched
  * @kobj:  kobject for sysfs resources
  * @stack_node:list node for klp_ops func_stack list
+ * @func_entry:links struct klp_func to struct klp_object
  * @old_size:  size of the old function
  * @new_size:  size of the new function
  * @patched:   the func has been added to the klp_ops list
@@ -80,6 +82,7 @@ struct klp_func {
unsigned long old_addr;
struct kobject kobj;
struct list_head stack_node;
+   struct list_head func_entry;
unsigned long old_size, new_size;
bool patched;
bool transition;
@@ -117,6 +120,8 @@ struct klp_callbacks {
  * @kobj:  kobject for sysfs resources
  * @mod:   kernel module associated with the patched object
  * (NULL for vmlinux)
+ * @func_list: head of list for struct klp_func
+ * @obj_entry: links struct klp_object to struct klp_patch
  * @patched:   the object's funcs have been added to the klp_ops list
  */
 struct klp_object {
@@ -127,6 +132,8 @@ struct klp_object {
 
/* internal */
struct kobject kobj;
+   struct list_head func_list;
+   struct list_head obj_entry;
struct module *mod;
bool patched;
 };
@@ -137,6 +144,7 @@ struct klp_object {
  * @objs:  object entries for kernel objects to be patched
  * @list:  list node for global list of registered patches
  * @kobj:  kobject for sysfs resources
+ * @obj_list:  head of list for struct klp_object
  * @enabled:   the patch is enabled (but operation may be incomplete)
  * @finish:for waiting till it is safe to remove the patch module
  */
@@ -148,18 +156,25 @@ struct klp_patch {
/* internal */
struct list_head list;
struct kobject kobj;
+   struct list_head obj_list;
bool enabled;
struct completion finish;
 };
 
-#define klp_for_each_object(patch, obj) \
+#define klp_for_each_object_static(patch, obj) \
for (obj = patch->objs; obj->funcs || obj->name; obj++)
 
-#define klp_for_each_func(obj, func) \
+#define klp_for_each_object(patch, obj)\
+   list_for_each_entry(obj, >obj_list, obj_entry)
+
+#define klp_for_each_func_static(obj, func) \
for (func = obj->funcs; \
 func->old_name || func->new_func || func->old_sympos; \
 func++)
 
+#define klp_for_each_func(obj, func)   \
+   list_for_each_entry(func, >func_list, func_entry)
+
 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 3a4656fb7047..1d525f4a270a 100644
--- a/kernel/livepatch/core.c
+++ b/kernel/livepatch/core.c
@@ -49,6 +49,32 @@ static LIST_HEAD(klp_patches);
 
 static struct kobject *klp_root_kobj;
 
+static void klp_init_func_list(struct klp_object *obj, struct klp_func *func)
+{
+   list_add(>func_entry, >func_list);
+}
+
+static void klp_init_object_list(struct klp_patch *patch,
+struct klp_object *obj)
+{
+   struct klp_func *func;
+
+   list_add(>obj_entry, >obj_list);
+
+   INIT_LIST_HEAD(>func_list);
+   klp_for_each_func_static(obj, func)
+   klp_init_func_list(obj, func);
+}
+
+static void klp_init_patch_list(struct klp_patch *patch)
+{
+   struct klp_object *obj;
+
+   INIT_LIST_HEAD(>obj_list);
+   klp_for_each_object_static(patch, obj)
+