diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2022-01-16 11:08:13 +0300 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2022-01-16 11:08:13 +0300 |
commit | 77dbd72b982ca648b42b4feac5f8b2ea55e4ed09 (patch) | |
tree | d85f5f036b2416ec9c0136954a3a52e69ceb887d | |
parent | d0a231f01e5b25bacd23e6edc7c979a18a517b2b (diff) | |
parent | b2dfc3fe73b5b305b13467e39386f77133590ea8 (diff) | |
download | linux-77dbd72b982ca648b42b4feac5f8b2ea55e4ed09.tar.xz |
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
-rw-r--r-- | Documentation/livepatch/api.rst | 30 | ||||
-rw-r--r-- | Documentation/livepatch/index.rst | 1 | ||||
-rw-r--r-- | Documentation/livepatch/shadow-vars.rst | 4 | ||||
-rw-r--r-- | Documentation/livepatch/system-state.rst | 4 | ||||
-rw-r--r-- | kernel/kallsyms.c | 1 | ||||
-rw-r--r-- | kernel/livepatch/core.c | 29 | ||||
-rw-r--r-- | kernel/livepatch/shadow.c | 6 | ||||
-rw-r--r-- | kernel/module.c | 2 |
8 files changed, 54 insertions, 23 deletions
diff --git a/Documentation/livepatch/api.rst b/Documentation/livepatch/api.rst new file mode 100644 index 000000000000..78944b63d74b --- /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 43cce5fad705..cebf1c71d4a5 100644 --- a/Documentation/livepatch/index.rst +++ b/Documentation/livepatch/index.rst @@ -14,6 +14,7 @@ Kernel Livepatching 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 6a7d43a8787d..7a7098bfb5c8 100644 --- a/Documentation/livepatch/shadow-vars.rst +++ b/Documentation/livepatch/shadow-vars.rst @@ -82,8 +82,8 @@ to do actions that can be done only once when a new variable is allocated. - 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 c6d127c2d9aa..7a3935fd812b 100644 --- a/Documentation/livepatch/system-state.rst +++ b/Documentation/livepatch/system-state.rst @@ -52,12 +52,12 @@ struct klp_state: 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 3011bc33a5ba..951c93216fc4 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 335d988bd811..585494ec464f 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 @@ err: 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 e5c9fb295ba9..c2e724d97ddf 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 84a9141a5e15..24fc305afe95 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: |