diff options
| -rw-r--r-- | Documentation/livepatch/livepatch.txt | 24 | ||||
| -rw-r--r-- | kernel/livepatch/core.c | 6 |
2 files changed, 6 insertions, 24 deletions
diff --git a/Documentation/livepatch/livepatch.txt b/Documentation/livepatch/livepatch.txt index 1ae2de758c08..2d7ed09dbd59 100644 --- a/Documentation/livepatch/livepatch.txt +++ b/Documentation/livepatch/livepatch.txt @@ -429,30 +429,6 @@ See Documentation/ABI/testing/sysfs-kernel-livepatch for more details. The current Livepatch implementation has several limitations: - - + The patch must not change the semantic of the patched functions. - - The current implementation guarantees only that either the old - or the new function is called. The functions are patched one - by one. It means that the patch must _not_ change the semantic - of the function. - - - + Data structures can not be patched. - - There is no support to version data structures or anyhow migrate - one structure into another. Also the simple consistency model does - not allow to switch more functions atomically. - - Once there is more complex consistency mode, it will be possible to - use some workarounds. For example, it will be possible to use a hole - for a new member because the data structure is aligned. Or it will - be possible to use an existing member for something else. - - There are no plans to add more generic support for modified structures - at the moment. - - + Only functions that can be traced could be patched. Livepatch is based on the dynamic ftrace. In particular, functions diff --git a/kernel/livepatch/core.c b/kernel/livepatch/core.c index 3a4656fb7047..5b77a7314e01 100644 --- a/kernel/livepatch/core.c +++ b/kernel/livepatch/core.c @@ -678,6 +678,9 @@ static int klp_init_func(struct klp_object *obj, struct klp_func *func) if (!func->old_name || !func->new_func) return -EINVAL; + if (strlen(func->old_name) >= KSYM_NAME_LEN) + return -EINVAL; + INIT_LIST_HEAD(&func->stack_node); func->patched = false; func->transition = false; @@ -751,6 +754,9 @@ static int klp_init_object(struct klp_patch *patch, struct klp_object *obj) if (!obj->funcs) return -EINVAL; + if (klp_is_module(obj) && strlen(obj->name) >= MODULE_NAME_LEN) + return -EINVAL; + obj->patched = false; obj->mod = NULL; |