Skip to content

Commit

Permalink
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel…
Browse files Browse the repository at this point in the history 
…/git/livepatching/livepatching

Pull livepatching updates from Jiri Kosina:

 - livepatching kselftests improvements from Joe Lawrence and Miroslav
   Benes

 - making use of gcc's -flive-patching option when available, from
   Miroslav Benes

 - kobject handling cleanups, from Petr Mladek

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/livepatching/livepatching:
  livepatch: Remove duplicated code for early initialization
  livepatch: Remove custom kobject state handling
  livepatch: Convert error about unsupported reliable stacktrace into a warning
  selftests/livepatch: Add functions.sh to TEST_PROGS_EXTENDED
  kbuild: use -flive-patching when CONFIG_LIVEPATCH is enabled
  selftests/livepatch: use TEST_PROGS for test scripts
  • Loading branch information
@torvalds
torvalds committed May 7, 2019
2 parents b4dd05d + 1efbd99 commit 573de2a
Show file tree
Hide file tree
Showing 4 changed files with 45 additions and 56 deletions.
4 changes: 4 additions & 0 deletions Makefile
View file
Original file line number Diff line number Diff line change
Expand Up @@ -811,6 +811,10 @@ KBUILD_CFLAGS_KERNEL += -ffunction-sections -fdata-sections
LDFLAGS_vmlinux += --gc-sections
endif

ifdef CONFIG_LIVEPATCH
KBUILD_CFLAGS += $(call cc-option, -flive-patching=inline-clone)
endif

# arch Makefile may override CC so keep this after arch Makefile is included
NOSTDINC_FLAGS += -nostdinc -isystem $(shell $(CC) -print-file-name=include)

Expand Down
3 changes: 0 additions & 3 deletions include/linux/livepatch.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -86,7 +86,6 @@ struct klp_func {
struct list_head node;
struct list_head stack_node;
unsigned long old_size, new_size;
bool kobj_added;
bool nop;
bool patched;
bool transition;
Expand Down Expand Up @@ -141,7 +140,6 @@ struct klp_object {
struct list_head func_list;
struct list_head node;
struct module *mod;
bool kobj_added;
bool dynamic;
bool patched;
};
Expand Down Expand Up @@ -170,7 +168,6 @@ struct klp_patch {
struct list_head list;
struct kobject kobj;
struct list_head obj_list;
bool kobj_added;
bool enabled;
bool forced;
struct work_struct free_work;
Expand Down
91 changes: 39 additions & 52 deletions kernel/livepatch/core.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -426,7 +426,13 @@ static void klp_free_object_dynamic(struct klp_object *obj)
kfree(obj);
}

static struct klp_object *klp_alloc_object_dynamic(const char *name)
static void klp_init_func_early(struct klp_object *obj,
struct klp_func *func);
static void klp_init_object_early(struct klp_patch *patch,
struct klp_object *obj);

static struct klp_object *klp_alloc_object_dynamic(const char *name,
struct klp_patch *patch)
{
struct klp_object *obj;

Expand All @@ -442,7 +448,7 @@ static struct klp_object *klp_alloc_object_dynamic(const char *name)
}
}

INIT_LIST_HEAD(&obj->func_list);
klp_init_object_early(patch, obj);
obj->dynamic = true;

return obj;
Expand Down Expand Up @@ -471,6 +477,7 @@ static struct klp_func *klp_alloc_func_nop(struct klp_func *old_func,
}
}

klp_init_func_early(obj, func);
/*
* func->new_func is same as func->old_func. These addresses are
* set when the object is loaded, see klp_init_object_loaded().
Expand All @@ -490,11 +497,9 @@ static int klp_add_object_nops(struct klp_patch *patch,
obj = klp_find_object(patch, old_obj);

if (!obj) {
obj = klp_alloc_object_dynamic(old_obj->name);
obj = klp_alloc_object_dynamic(old_obj->name, patch);
if (!obj)
return -ENOMEM;

list_add_tail(&obj->node, &patch->obj_list);
}

klp_for_each_func(old_obj, old_func) {
Expand All @@ -505,8 +510,6 @@ static int klp_add_object_nops(struct klp_patch *patch,
func = klp_alloc_func_nop(old_func, obj);
if (!func)
return -ENOMEM;

list_add_tail(&func->node, &obj->func_list);
}

return 0;
Expand Down Expand Up @@ -588,13 +591,7 @@ static void __klp_free_funcs(struct klp_object *obj, bool nops_only)
continue;

list_del(&func->node);

/* Might be called from klp_init_patch() error path. */
if (func->kobj_added) {
kobject_put(&func->kobj);
} else if (func->nop) {
klp_free_func_nop(func);
}
kobject_put(&func->kobj);
}
}

Expand Down Expand Up @@ -624,13 +621,7 @@ static void __klp_free_objects(struct klp_patch *patch, bool nops_only)
continue;

list_del(&obj->node);

/* Might be called from klp_init_patch() error path. */
if (obj->kobj_added) {
kobject_put(&obj->kobj);
} else if (obj->dynamic) {
klp_free_object_dynamic(obj);
}
kobject_put(&obj->kobj);
}
}

Expand Down Expand Up @@ -675,10 +666,8 @@ static void klp_free_patch_finish(struct klp_patch *patch)
* this is called when the patch gets disabled and it
* cannot get enabled again.
*/
if (patch->kobj_added) {
kobject_put(&patch->kobj);
wait_for_completion(&patch->finish);
}
kobject_put(&patch->kobj);
wait_for_completion(&patch->finish);

/* Put the module after the last access to struct klp_patch. */
if (!patch->forced)
Expand All @@ -700,8 +689,6 @@ static void klp_free_patch_work_fn(struct work_struct *work)

static int klp_init_func(struct klp_object *obj, struct klp_func *func)
{
int ret;

if (!func->old_name)
return -EINVAL;

Expand All @@ -724,13 +711,9 @@ static int klp_init_func(struct klp_object *obj, struct klp_func *func)
* object. If the user selects 0 for old_sympos, then 1 will be used
* since a unique symbol will be the first occurrence.
*/
ret = kobject_init_and_add(&func->kobj, &klp_ktype_func,
&obj->kobj, "%s,%lu", func->old_name,
func->old_sympos ? func->old_sympos : 1);
if (!ret)
func->kobj_added = true;

return ret;
return kobject_add(&func->kobj, &obj->kobj, "%s,%lu",
func->old_name,
func->old_sympos ? func->old_sympos : 1);
}

/* Arches may override this to finish any remaining arch-specific tasks */
Expand Down Expand Up @@ -801,11 +784,9 @@ static int klp_init_object(struct klp_patch *patch, struct klp_object *obj)
klp_find_object_module(obj);

name = klp_is_module(obj) ? obj->name : "vmlinux";
ret = kobject_init_and_add(&obj->kobj, &klp_ktype_object,
&patch->kobj, "%s", name);
ret = kobject_add(&obj->kobj, &patch->kobj, "%s", name);
if (ret)
return ret;
obj->kobj_added = true;

klp_for_each_func(obj, func) {
ret = klp_init_func(obj, func);
Expand All @@ -819,6 +800,21 @@ static int klp_init_object(struct klp_patch *patch, struct klp_object *obj)
return ret;
}

static void klp_init_func_early(struct klp_object *obj,
struct klp_func *func)
{
kobject_init(&func->kobj, &klp_ktype_func);
list_add_tail(&func->node, &obj->func_list);
}

static void klp_init_object_early(struct klp_patch *patch,
struct klp_object *obj)
{
INIT_LIST_HEAD(&obj->func_list);
kobject_init(&obj->kobj, &klp_ktype_object);
list_add_tail(&obj->node, &patch->obj_list);
}

static int klp_init_patch_early(struct klp_patch *patch)
{
struct klp_object *obj;
Expand All @@ -829,7 +825,7 @@ static int klp_init_patch_early(struct klp_patch *patch)

INIT_LIST_HEAD(&patch->list);
INIT_LIST_HEAD(&patch->obj_list);
patch->kobj_added = false;
kobject_init(&patch->kobj, &klp_ktype_patch);
patch->enabled = false;
patch->forced = false;
INIT_WORK(&patch->free_work, klp_free_patch_work_fn);
Expand All @@ -839,13 +835,10 @@ static int klp_init_patch_early(struct klp_patch *patch)
if (!obj->funcs)
return -EINVAL;

INIT_LIST_HEAD(&obj->func_list);
obj->kobj_added = false;
list_add_tail(&obj->node, &patch->obj_list);
klp_init_object_early(patch, obj);

klp_for_each_func_static(obj, func) {
func->kobj_added = false;
list_add_tail(&func->node, &obj->func_list);
klp_init_func_early(obj, func);
}
}

Expand All @@ -860,11 +853,9 @@ static int klp_init_patch(struct klp_patch *patch)
struct klp_object *obj;
int ret;

ret = kobject_init_and_add(&patch->kobj, &klp_ktype_patch,
klp_root_kobj, "%s", patch->mod->name);
ret = kobject_add(&patch->kobj, klp_root_kobj, "%s", patch->mod->name);
if (ret)
return ret;
patch->kobj_added = true;

if (patch->replace) {
ret = klp_add_nops(patch);
Expand Down Expand Up @@ -926,9 +917,6 @@ static int __klp_enable_patch(struct klp_patch *patch)
if (WARN_ON(patch->enabled))
return -EINVAL;

if (!patch->kobj_added)
return -EINVAL;

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

klp_init_transition(patch, KLP_PATCHED);
Expand Down Expand Up @@ -1003,11 +991,10 @@ int klp_enable_patch(struct klp_patch *patch)
return -ENODEV;

if (!klp_have_reliable_stack()) {
pr_err("This architecture doesn't have support for the livepatch consistency model.\n");
return -EOPNOTSUPP;
pr_warn("This architecture doesn't have support for the livepatch consistency model.\n");
pr_warn("The livepatch transition may never complete.\n");
}


mutex_lock(&klp_mutex);

ret = klp_init_patch_early(patch);
Expand Down
3 changes: 2 additions & 1 deletion tools/testing/selftests/livepatch/Makefile
View file
Original file line number Diff line number Diff line change
@@ -1,6 +1,7 @@
# SPDX-License-Identifier: GPL-2.0

TEST_GEN_PROGS := \
TEST_PROGS_EXTENDED := functions.sh
TEST_PROGS := \
test-livepatch.sh \
test-callbacks.sh \
test-shadow-vars.sh
Expand Down

0 comments on commit 573de2a

Please sign in to comment.