Merge branch 'for-4.2' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/libata

[firefly-linux-kernel-4.4.55.git] / kernel / livepatch / core.c

diff --git a/kernel/livepatch/core.c b/kernel/livepatch/core.c
index 0e7c23c6cf3fd555353f156a2504000f3be4ff90..c40ebcca0495fc5fb003e44c4c6549bc39fcd08d 100644 (file)
--- a/kernel/livepatch/core.c
+++ b/kernel/livepatch/core.c
@@ -128,7 +128,7 @@ static bool klp_is_patch_registered(struct klp_patch *patch)
 
 static bool klp_initialized(void)
 {
-       return klp_root_kobj;
+       return !!klp_root_kobj;
 }
 
 struct klp_find_arg {
@@ -179,7 +179,9 @@ static int klp_find_object_symbol(const char *objname, const char *name,
                .count = 0
        };
 
+       mutex_lock(&module_mutex);
        kallsyms_on_each_symbol(klp_find_callback, &args);
+       mutex_unlock(&module_mutex);
 
        if (args.count == 0)
                pr_err("symbol '%s' not found in symbol table\n", name);
@@ -219,13 +221,19 @@ static int klp_verify_vmlinux_symbol(const char *name, unsigned long addr)
                .name = name,
                .addr = addr,
        };
+       int ret;
 
-       if (kallsyms_on_each_symbol(klp_verify_callback, &args))
-               return 0;
+       mutex_lock(&module_mutex);
+       ret = kallsyms_on_each_symbol(klp_verify_callback, &args);
+       mutex_unlock(&module_mutex);
 
-       pr_err("symbol '%s' not found at specified address 0x%016lx, kernel mismatch?\n",
-               name, addr);
-       return -EINVAL;
+       if (!ret) {
+               pr_err("symbol '%s' not found at specified address 0x%016lx, kernel mismatch?\n",
+                       name, addr);
+               return -EINVAL;
+       }
+
+       return 0;
 }
 
 static int klp_find_verify_func_addr(struct klp_object *obj,
@@ -423,7 +431,7 @@ static void klp_disable_object(struct klp_object *obj)
 {
        struct klp_func *func;
 
-       for (func = obj->funcs; func->old_name; func++)
+       klp_for_each_func(obj, func)
                if (func->state == KLP_ENABLED)
                        klp_disable_func(func);
 
@@ -441,7 +449,7 @@ static int klp_enable_object(struct klp_object *obj)
        if (WARN_ON(!klp_is_object_loaded(obj)))
                return -EINVAL;
 
-       for (func = obj->funcs; func->old_name; func++) {
+       klp_for_each_func(obj, func) {
                ret = klp_enable_func(func);
                if (ret) {
                        klp_disable_object(obj);
@@ -464,7 +472,7 @@ static int __klp_disable_patch(struct klp_patch *patch)
 
        pr_notice("disabling patch '%s'\n", patch->mod->name);
 
-       for (obj = patch->objs; obj->funcs; obj++) {
+       klp_for_each_object(patch, obj) {
                if (obj->state == KLP_ENABLED)
                        klp_disable_object(obj);
        }
@@ -524,7 +532,7 @@ static int __klp_enable_patch(struct klp_patch *patch)
 
        pr_notice("enabling patch '%s'\n", patch->mod->name);
 
-       for (obj = patch->objs; obj->funcs; obj++) {
+       klp_for_each_object(patch, obj) {
                if (!klp_is_object_loaded(obj))
                        continue;
 
@@ -652,6 +660,15 @@ static struct kobj_type klp_ktype_patch = {
        .default_attrs = klp_patch_attrs,
 };
 
+static void klp_kobj_release_object(struct kobject *kobj)
+{
+}
+
+static struct kobj_type klp_ktype_object = {
+       .release = klp_kobj_release_object,
+       .sysfs_ops = &kobj_sysfs_ops,
+};
+
 static void klp_kobj_release_func(struct kobject *kobj)
 {
 }
@@ -681,7 +698,7 @@ static void klp_free_object_loaded(struct klp_object *obj)
 
        obj->mod = NULL;
 
-       for (func = obj->funcs; func->old_name; func++)
+       klp_for_each_func(obj, func)
                func->old_addr = 0;
 }
 
@@ -696,7 +713,7 @@ static void klp_free_objects_limited(struct klp_patch *patch,
 
        for (obj = patch->objs; obj->funcs && obj != limit; obj++) {
                klp_free_funcs_limited(obj, NULL);
-               kobject_put(obj->kobj);
+               kobject_put(&obj->kobj);
        }
 }
 
@@ -714,7 +731,7 @@ static int klp_init_func(struct klp_object *obj, struct klp_func *func)
        func->state = KLP_DISABLED;
 
        return kobject_init_and_add(&func->kobj, &klp_ktype_func,
-                                   obj->kobj, "%s", func->old_name);
+                                   &obj->kobj, "%s", func->old_name);
 }
 
 /* parts of the initialization that is done only when the object is loaded */
@@ -730,7 +747,7 @@ static int klp_init_object_loaded(struct klp_patch *patch,
                        return ret;
        }
 
-       for (func = obj->funcs; func->old_name; func++) {
+       klp_for_each_func(obj, func) {
                ret = klp_find_verify_func_addr(obj, func);
                if (ret)
                        return ret;
@@ -754,11 +771,12 @@ 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";
-       obj->kobj = kobject_create_and_add(name, &patch->kobj);
-       if (!obj->kobj)
-               return -ENOMEM;
+       ret = kobject_init_and_add(&obj->kobj, &klp_ktype_object,
+                                  &patch->kobj, "%s", name);
+       if (ret)
+               return ret;
 
-       for (func = obj->funcs; func->old_name; func++) {
+       klp_for_each_func(obj, func) {
                ret = klp_init_func(obj, func);
                if (ret)
                        goto free;
@@ -774,7 +792,7 @@ static int klp_init_object(struct klp_patch *patch, struct klp_object *obj)
 
 free:
        klp_free_funcs_limited(obj, func);
-       kobject_put(obj->kobj);
+       kobject_put(&obj->kobj);
        return ret;
 }
 
@@ -795,7 +813,7 @@ static int klp_init_patch(struct klp_patch *patch)
        if (ret)
                goto unlock;
 
-       for (obj = patch->objs; obj->funcs; obj++) {
+       klp_for_each_object(patch, obj) {
                ret = klp_init_object(patch, obj);
                if (ret)
                        goto free;
@@ -884,7 +902,7 @@ int klp_register_patch(struct klp_patch *patch)
 }
 EXPORT_SYMBOL_GPL(klp_register_patch);
 
-static void klp_module_notify_coming(struct klp_patch *patch,
+static int klp_module_notify_coming(struct klp_patch *patch,
                                     struct klp_object *obj)
 {
        struct module *pmod = patch->mod;
@@ -892,22 +910,23 @@ static void klp_module_notify_coming(struct klp_patch *patch,
        int ret;
 
        ret = klp_init_object_loaded(patch, obj);
-       if (ret)
-               goto err;
+       if (ret) {
+               pr_warn("failed to initialize patch '%s' for module '%s' (%d)\n",
+                       pmod->name, mod->name, ret);
+               return ret;
+       }
 
        if (patch->state == KLP_DISABLED)
-               return;
+               return 0;
 
        pr_notice("applying patch '%s' to loading module '%s'\n",
                  pmod->name, mod->name);
 
        ret = klp_enable_object(obj);
-       if (!ret)
-               return;
-
-err:
-       pr_warn("failed to apply patch '%s' to module '%s' (%d)\n",
-               pmod->name, mod->name, ret);
+       if (ret)
+               pr_warn("failed to apply patch '%s' to module '%s' (%d)\n",
+                       pmod->name, mod->name, ret);
+       return ret;
 }
 
 static void klp_module_notify_going(struct klp_patch *patch,
@@ -931,6 +950,7 @@ disabled:
 static int klp_module_notify(struct notifier_block *nb, unsigned long action,
                             void *data)
 {
+       int ret;
        struct module *mod = data;
        struct klp_patch *patch;
        struct klp_object *obj;
@@ -950,13 +970,18 @@ static int klp_module_notify(struct notifier_block *nb, unsigned long action,
                mod->klp_alive = false;
 
        list_for_each_entry(patch, &klp_patches, list) {
-               for (obj = patch->objs; obj->funcs; obj++) {
+               klp_for_each_object(patch, obj) {
                        if (!klp_is_module(obj) || strcmp(obj->name, mod->name))
                                continue;
 
                        if (action == MODULE_STATE_COMING) {
                                obj->mod = mod;
-                               klp_module_notify_coming(patch, obj);
+                               ret = klp_module_notify_coming(patch, obj);
+                               if (ret) {
+                                       obj->mod = NULL;
+                                       pr_warn("patch '%s' is in an inconsistent state!\n",
+                                               patch->mod->name);
+                               }
                        } else /* MODULE_STATE_GOING */
                                klp_module_notify_going(patch, obj);
 
@@ -974,7 +999,7 @@ static struct notifier_block klp_module_nb = {
        .priority = INT_MIN+1, /* called late but before ftrace notifier */
 };
 
-static int klp_init(void)
+static int __init klp_init(void)
 {
        int ret;