mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-04 02:06:43 +07:00
livepatch: Shuffle klp_enable_patch()/klp_disable_patch() code
We are going to simplify the API and code by removing the registration step. This would require calling init/free functions from enable/disable ones. This patch just moves the code to prevent more forward declarations. This patch does not change the code except for two forward declarations. Signed-off-by: Petr Mladek <pmladek@suse.com> Acked-by: Miroslav Benes <mbenes@suse.cz> Acked-by: Joe Lawrence <joe.lawrence@redhat.com> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
This commit is contained in:
Petr Mladek
Jiri Kosina
parent
19514910d0
commit
26c3e98e2f
@ -278,170 +278,6 @@ static int klp_write_object_relocations(struct module *pmod,
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return ret;
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}
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static int __klp_disable_patch(struct klp_patch *patch)
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{
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struct klp_object *obj;
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if (WARN_ON(!patch->enabled))
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return -EINVAL;
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if (klp_transition_patch)
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return -EBUSY;
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/* enforce stacking: only the last enabled patch can be disabled */
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if (!list_is_last(&patch->list, &klp_patches) &&
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list_next_entry(patch, list)->enabled)
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return -EBUSY;
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klp_init_transition(patch, KLP_UNPATCHED);
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klp_for_each_object(patch, obj)
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if (obj->patched)
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klp_pre_unpatch_callback(obj);
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/*
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* Enforce the order of the func->transition writes in
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* klp_init_transition() and the TIF_PATCH_PENDING writes in
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* klp_start_transition(). In the rare case where klp_ftrace_handler()
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* is called shortly after klp_update_patch_state() switches the task,
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* this ensures the handler sees that func->transition is set.
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*/
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smp_wmb();
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klp_start_transition();
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klp_try_complete_transition();
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patch->enabled = false;
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return 0;
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}
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/**
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* klp_disable_patch() - disables a registered patch
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* @patch: The registered, enabled patch to be disabled
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*
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* Unregisters the patched functions from ftrace.
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*
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* Return: 0 on success, otherwise error
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*/
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int klp_disable_patch(struct klp_patch *patch)
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{
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int ret;
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mutex_lock(&klp_mutex);
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if (!klp_is_patch_registered(patch)) {
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ret = -EINVAL;
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goto err;
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}
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if (!patch->enabled) {
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ret = -EINVAL;
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goto err;
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}
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ret = __klp_disable_patch(patch);
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err:
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mutex_unlock(&klp_mutex);
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return ret;
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}
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EXPORT_SYMBOL_GPL(klp_disable_patch);
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static int __klp_enable_patch(struct klp_patch *patch)
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{
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struct klp_object *obj;
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int ret;
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if (klp_transition_patch)
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return -EBUSY;
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if (WARN_ON(patch->enabled))
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return -EINVAL;
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/* enforce stacking: only the first disabled patch can be enabled */
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if (patch->list.prev != &klp_patches &&
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!list_prev_entry(patch, list)->enabled)
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return -EBUSY;
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/*
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* A reference is taken on the patch module to prevent it from being
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* unloaded.
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*/
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if (!try_module_get(patch->mod))
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return -ENODEV;
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pr_notice("enabling patch '%s'\n", patch->mod->name);
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klp_init_transition(patch, KLP_PATCHED);
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/*
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* Enforce the order of the func->transition writes in
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* klp_init_transition() and the ops->func_stack writes in
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* klp_patch_object(), so that klp_ftrace_handler() will see the
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* func->transition updates before the handler is registered and the
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* new funcs become visible to the handler.
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*/
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smp_wmb();
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klp_for_each_object(patch, obj) {
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if (!klp_is_object_loaded(obj))
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continue;
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ret = klp_pre_patch_callback(obj);
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if (ret) {
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pr_warn("pre-patch callback failed for object '%s'\n",
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klp_is_module(obj) ? obj->name : "vmlinux");
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goto err;
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}
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ret = klp_patch_object(obj);
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if (ret) {
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pr_warn("failed to patch object '%s'\n",
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klp_is_module(obj) ? obj->name : "vmlinux");
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goto err;
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}
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}
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klp_start_transition();
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klp_try_complete_transition();
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patch->enabled = true;
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return 0;
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err:
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pr_warn("failed to enable patch '%s'\n", patch->mod->name);
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klp_cancel_transition();
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return ret;
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}
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/**
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* klp_enable_patch() - enables a registered patch
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* @patch: The registered, disabled patch to be enabled
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*
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* Performs the needed symbol lookups and code relocations,
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* then registers the patched functions with ftrace.
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*
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* Return: 0 on success, otherwise error
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*/
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int klp_enable_patch(struct klp_patch *patch)
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{
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int ret;
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mutex_lock(&klp_mutex);
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if (!klp_is_patch_registered(patch)) {
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ret = -EINVAL;
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goto err;
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}
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ret = __klp_enable_patch(patch);
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err:
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mutex_unlock(&klp_mutex);
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return ret;
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}
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EXPORT_SYMBOL_GPL(klp_enable_patch);
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/*
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* Sysfs Interface
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*
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@ -454,6 +290,8 @@ EXPORT_SYMBOL_GPL(klp_enable_patch);
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* /sys/kernel/livepatch/<patch>/<object>
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* /sys/kernel/livepatch/<patch>/<object>/<function,sympos>
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*/
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static int __klp_disable_patch(struct klp_patch *patch);
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static int __klp_enable_patch(struct klp_patch *patch);
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static ssize_t enabled_store(struct kobject *kobj, struct kobj_attribute *attr,
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const char *buf, size_t count)
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@ -904,6 +742,170 @@ int klp_register_patch(struct klp_patch *patch)
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}
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EXPORT_SYMBOL_GPL(klp_register_patch);
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static int __klp_disable_patch(struct klp_patch *patch)
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{
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struct klp_object *obj;
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if (WARN_ON(!patch->enabled))
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return -EINVAL;
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if (klp_transition_patch)
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return -EBUSY;
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/* enforce stacking: only the last enabled patch can be disabled */
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if (!list_is_last(&patch->list, &klp_patches) &&
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list_next_entry(patch, list)->enabled)
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return -EBUSY;
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klp_init_transition(patch, KLP_UNPATCHED);
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klp_for_each_object(patch, obj)
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if (obj->patched)
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klp_pre_unpatch_callback(obj);
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/*
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* Enforce the order of the func->transition writes in
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* klp_init_transition() and the TIF_PATCH_PENDING writes in
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* klp_start_transition(). In the rare case where klp_ftrace_handler()
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* is called shortly after klp_update_patch_state() switches the task,
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* this ensures the handler sees that func->transition is set.
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*/
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smp_wmb();
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klp_start_transition();
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klp_try_complete_transition();
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patch->enabled = false;
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return 0;
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}
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/**
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* klp_disable_patch() - disables a registered patch
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* @patch: The registered, enabled patch to be disabled
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*
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* Unregisters the patched functions from ftrace.
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*
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* Return: 0 on success, otherwise error
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*/
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int klp_disable_patch(struct klp_patch *patch)
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{
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int ret;
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mutex_lock(&klp_mutex);
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if (!klp_is_patch_registered(patch)) {
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ret = -EINVAL;
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goto err;
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}
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if (!patch->enabled) {
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ret = -EINVAL;
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goto err;
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}
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ret = __klp_disable_patch(patch);
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err:
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mutex_unlock(&klp_mutex);
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return ret;
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}
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EXPORT_SYMBOL_GPL(klp_disable_patch);
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static int __klp_enable_patch(struct klp_patch *patch)
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{
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struct klp_object *obj;
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int ret;
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if (klp_transition_patch)
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return -EBUSY;
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if (WARN_ON(patch->enabled))
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return -EINVAL;
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/* enforce stacking: only the first disabled patch can be enabled */
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if (patch->list.prev != &klp_patches &&
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!list_prev_entry(patch, list)->enabled)
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return -EBUSY;
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/*
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* A reference is taken on the patch module to prevent it from being
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* unloaded.
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*/
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if (!try_module_get(patch->mod))
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return -ENODEV;
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pr_notice("enabling patch '%s'\n", patch->mod->name);
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klp_init_transition(patch, KLP_PATCHED);
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/*
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* Enforce the order of the func->transition writes in
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* klp_init_transition() and the ops->func_stack writes in
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* klp_patch_object(), so that klp_ftrace_handler() will see the
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* func->transition updates before the handler is registered and the
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* new funcs become visible to the handler.
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*/
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smp_wmb();
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klp_for_each_object(patch, obj) {
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if (!klp_is_object_loaded(obj))
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continue;
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ret = klp_pre_patch_callback(obj);
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if (ret) {
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pr_warn("pre-patch callback failed for object '%s'\n",
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klp_is_module(obj) ? obj->name : "vmlinux");
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goto err;
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}
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ret = klp_patch_object(obj);
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if (ret) {
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pr_warn("failed to patch object '%s'\n",
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klp_is_module(obj) ? obj->name : "vmlinux");
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goto err;
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}
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}
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klp_start_transition();
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klp_try_complete_transition();
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patch->enabled = true;
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return 0;
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err:
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pr_warn("failed to enable patch '%s'\n", patch->mod->name);
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klp_cancel_transition();
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return ret;
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}
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/**
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* klp_enable_patch() - enables a registered patch
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* @patch: The registered, disabled patch to be enabled
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*
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* Performs the needed symbol lookups and code relocations,
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* then registers the patched functions with ftrace.
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*
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* Return: 0 on success, otherwise error
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*/
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int klp_enable_patch(struct klp_patch *patch)
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{
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int ret;
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mutex_lock(&klp_mutex);
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if (!klp_is_patch_registered(patch)) {
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ret = -EINVAL;
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goto err;
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}
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ret = __klp_enable_patch(patch);
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err:
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mutex_unlock(&klp_mutex);
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return ret;
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}
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EXPORT_SYMBOL_GPL(klp_enable_patch);
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/*
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* Remove parts of patches that touch a given kernel module. The list of
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* patches processed might be limited. When limit is NULL, all patches
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