On 2015/1/21 22:08, Jiri Kosina wrote:
> On Wed, 21 Jan 2015, Li Bin wrote:
>
>> for disable_patch:
>> The patch is unallowed to be disabled if one patch after has
>> dependencies with it and has been enabled.
>>
>> for enable_patch:
>> The patch is unallowed to be enabled if one patch before has
>> dependencies with it and has been disabled.
>>
>> Signed-off-by: Li Bin <huawei.li...@huawei.com>
>> ---
>> kernel/livepatch/core.c | 60
>> +++++++++++++++++++++++++++++++++++++++++++++++
>> 1 files changed, 60 insertions(+), 0 deletions(-)
>>
>> diff --git a/kernel/livepatch/core.c b/kernel/livepatch/core.c
>> index 7861ed2..a12a31c 100644
>> --- a/kernel/livepatch/core.c
>> +++ b/kernel/livepatch/core.c
>> @@ -114,6 +114,21 @@ static bool klp_is_patch_registered(struct klp_patch
>> *patch)
>> return false;
>> }
>>
>> +static bool klp_func_in_patch(struct klp_func *kfunc, struct klp_patch
>> *patch)
>> +{
>> + struct klp_object *obj;
>> + struct klp_func *func;
>> +
>> + for (obj = patch->objs; obj->funcs; obj++) {
>> + for (func = obj->funcs; func->old_name; func++) {
>> + if (kfunc->old_addr == func->old_addr) {
>> + return true;
>> + }
>> + }
>> + }
>> + return false;
>> +}
>> +
>> static bool klp_initialized(void)
>> {
>> return klp_root_kobj;
>> @@ -466,8 +481,31 @@ unregister:
>> static int __klp_disable_patch(struct klp_patch *patch)
>> {
>> struct klp_object *obj;
>> + struct klp_patch *temp;
>> + struct klp_func *func;
>> int ret;
>>
>> + /*
>> + * the patch is unallowed to be disabled if one patch
>> + * after has dependencies with it and has been enabled.
>> + */
>> + for (temp = list_next_entry(patch, list);
>> + &temp->list != &klp_patches;
>> + temp = list_next_entry(temp, list)) {
>> + if (temp->state != KLP_ENABLED)
>> + continue;
>> +
>> + for (obj = patch->objs; obj->funcs; obj++) {
>> + for (func = obj->funcs; func->old_name; func++) {
>> + if (klp_func_in_patch(func, temp)) {
>> + pr_err("this patch depends on '%s',
>> please disable it firstly\n",
>> + temp->mod->name);
>> + return -EBUSY;
>> + }
>> + }
>> + }
>> + }
>> +
>> pr_notice("disabling patch '%s'\n", patch->mod->name);
>>
>> for (obj = patch->objs; obj->funcs; obj++) {
>> @@ -519,11 +557,33 @@ EXPORT_SYMBOL_GPL(klp_disable_patch);
>> static int __klp_enable_patch(struct klp_patch *patch)
>> {
>> struct klp_object *obj;
>> + struct klp_patch *temp;
>> + struct klp_func *func;
>> int ret;
>>
>> if (WARN_ON(patch->state != KLP_DISABLED))
>> return -EINVAL;
>>
>> + /*
>> + * the patch is unallowed to be enabled if one patch
>> + * before has dependencies with it and has been disabled.
>> + */
>> + for (temp = list_first_entry(&klp_patches, struct klp_patch, list);
>> + temp != patch; temp = list_next_entry(temp, list)) {
>> + if (temp->state != KLP_DISABLED)
>> + continue;
>> +
>> + for (obj = patch->objs; obj->funcs; obj++) {
>> + for (func = obj->funcs; func->old_name; func++) {
>> + if (klp_func_in_patch(func, temp)) {
>> + pr_err("this patch depends on '%s',
>> please enable it firstly\n",
>> + temp->mod->name);
>> + return -EBUSY;
>
> By this you limit the definition of the patch inter-dependency to just
> symbols. But that's not the only way how patches can depend on it other --
> the dependency can be semantical.
Yes, I agree with you. But I think the other dependencies such as semantical
dependency should be judged by the user, like reverting a patch from git
repository.
Right?
Thanks,
Li Bin
>
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