[PATCH v2 1/2] livepatch: use arch_klp_init_object_loaded() to finish arch-specific tasks

From: Jessica Yu
Date: Thu Jul 21 2016 - 01:24:39 EST


Introduce arch_klp_init_object_loaded() to complete any additional
arch-specific tasks during patching. Architecture code may override this
function.

Signed-off-by: Jessica Yu <jeyu@xxxxxxxxxx>
---
include/linux/livepatch.h | 3 +++
kernel/livepatch/core.c | 12 ++++++++++--
2 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/include/linux/livepatch.h b/include/linux/livepatch.h
index a93a0b2..9072f04 100644
--- a/include/linux/livepatch.h
+++ b/include/linux/livepatch.h
@@ -116,6 +116,9 @@ int klp_unregister_patch(struct klp_patch *);
int klp_enable_patch(struct klp_patch *);
int klp_disable_patch(struct klp_patch *);

+void arch_klp_init_object_loaded(struct klp_patch *patch,
+ struct klp_object *obj);
+
/* Called from the module loader during module coming/going states */
int klp_module_coming(struct module *mod);
void klp_module_going(struct module *mod);
diff --git a/kernel/livepatch/core.c b/kernel/livepatch/core.c
index 5c2bc10..164eff6 100644
--- a/kernel/livepatch/core.c
+++ b/kernel/livepatch/core.c
@@ -274,7 +274,6 @@ static int klp_write_object_relocations(struct module *pmod,

objname = klp_is_module(obj) ? obj->name : "vmlinux";

- module_disable_ro(pmod);
/* For each klp relocation section */
for (i = 1; i < pmod->klp_info->hdr.e_shnum; i++) {
sec = pmod->klp_info->sechdrs + i;
@@ -309,7 +308,6 @@ static int klp_write_object_relocations(struct module *pmod,
break;
}

- module_enable_ro(pmod);
return ret;
}

@@ -763,6 +761,12 @@ static int klp_init_func(struct klp_object *obj, struct klp_func *func)
func->old_sympos ? func->old_sympos : 1);
}

+/* Arches may override this to finish any remaining arch-specific tasks */
+void __weak arch_klp_init_object_loaded(struct klp_patch *patch,
+ struct klp_object *obj)
+{
+}
+
/* parts of the initialization that is done only when the object is loaded */
static int klp_init_object_loaded(struct klp_patch *patch,
struct klp_object *obj)
@@ -770,10 +774,14 @@ static int klp_init_object_loaded(struct klp_patch *patch,
struct klp_func *func;
int ret;

+ module_disable_ro(patch->mod);
ret = klp_write_object_relocations(patch->mod, obj);
if (ret)
return ret;

+ arch_klp_init_object_loaded(patch, obj);
+ module_enable_ro(patch->mod);
+
klp_for_each_func(obj, func) {
ret = klp_find_object_symbol(obj->name, func->old_name,
func->old_sympos,
--
2.5.5