[RFC PATCH 43/56] module: Update alternatives

[David Kaplan <david.kaplan@amd.com>]

Update alternatives in modules by making the module text writeable and
then calling the arch-specific update alternatives function.

Signed-off-by: David Kaplan <david.kaplan@amd.com>
---
 include/linux/module.h |  6 ++++++
 kernel/module/main.c   | 42 ++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 48 insertions(+)

diff --git a/include/linux/module.h b/include/linux/module.h
index 2d8c34cb961f..f29974cae6bc 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -1023,6 +1023,12 @@ DEFINE_FREE(module_put, struct module *, if (_T) module_put(_T))
 #ifdef CONFIG_DYNAMIC_MITIGATIONS
 void modules_prepare_repatch(void);
 void modules_post_repatch(void);
+void modules_update_alternatives(void);
+void arch_module_update_alternatives(struct module *mod);
+void arch_module_pre_update_alternatives(struct module *mod);
+void arch_module_post_update_alternatives(struct module *mod);
+void modules_pre_update_alternatives(void);
+void modules_post_update_alternatives(void);
 #endif
 
 #endif /* _LINUX_MODULE_H */
diff --git a/kernel/module/main.c b/kernel/module/main.c
index 0525b1c6d5b9..fa46ce4285dd 100644
--- a/kernel/module/main.c
+++ b/kernel/module/main.c
@@ -3943,4 +3943,46 @@ void modules_post_repatch(void)
 		change_mod_mem_perm(mod, MOD_TEXT, false);
 	}
 }
+
+void __weak arch_module_update_alternatives(struct module *mod)
+{
+}
+
+void modules_update_alternatives(void)
+{
+	struct module *mod;
+
+	list_for_each_entry(mod, &modules, list) {
+		arch_module_update_alternatives(mod);
+		update_all_static_calls(mod->static_call_sites,
+					mod->static_call_sites +
+					mod->num_static_call_sites, mod);
+	}
+}
+
+void __weak arch_module_pre_update_alternatives(struct module *mod)
+{
+}
+
+void __weak arch_module_post_update_alternatives(struct module *mod)
+{
+}
+
+void modules_pre_update_alternatives(void)
+{
+	struct module *mod;
+
+	list_for_each_entry(mod, &modules, list) {
+		arch_module_pre_update_alternatives(mod);
+	}
+}
+
+void modules_post_update_alternatives(void)
+{
+	struct module *mod;
+
+	list_for_each_entry(mod, &modules, list) {
+		arch_module_post_update_alternatives(mod);
+	}
+}
 #endif
-- 
2.34.1