On Thu 2022-02-10 11:44 +0000, Christophe Leroy wrote:

This change is wrong, build fails with it because is_livepatch_module()
is nowhere defined.

Yes, sorry about that. This was an omission/or oversight during the rebase
attempt.

You could move is_livepatch_module() to include/linux/livepatch.h but as
a separate patch.

Fair enough. Albeit, I'd prefer to revert and keep is_livepatch_module()
in include/linux/module.h - this is likely the best solution.
Note: set_livepatch_module() will remain for internal use only.

quoted

  #else /* !CONFIG_LIVEPATCH */
  static inline bool is_livepatch_module(struct module *mod)
  {

diff --git a/kernel/module/Makefile b/kernel/module/Makefile
index 2902fc7d0ef1..ee20d864ad19 100644
--- a/kernel/module/Makefile
+++ b/kernel/module/Makefile

@@ -7,3 +7,6 @@ obj-$(CONFIG_MODULES) += main.o
  obj-$(CONFIG_MODULE_DECOMPRESS) += decompress.o
  obj-$(CONFIG_MODULE_SIG) += signing.o
  obj-$(CONFIG_MODULE_SIG_FORMAT) += signature.o
+ifdef CONFIG_MODULES

CONFIG_LIVEPATCH depends on CONFIG_MODULES so this ifdef is not needed

Agreed.

Checkpatch reports the following:

WARNING: added, moved or deleted file(s), does MAINTAINERS need updating?
#80:
new file mode 100644

CHECK: Comparison to NULL could be written "!mod->klp_info"
#109: FILE: kernel/module/livepatch.c:25:
+    if (mod->klp_info == NULL)

CHECK: Comparison to NULL could be written "!mod->klp_info->sechdrs"
#119: FILE: kernel/module/livepatch.c:35:
+    if (mod->klp_info->sechdrs == NULL) {

CHECK: Comparison to NULL could be written "!mod->klp_info->secstrings"
#127: FILE: kernel/module/livepatch.c:43:
+    if (mod->klp_info->secstrings == NULL) {

CHECK: No space is necessary after a cast
#142: FILE: kernel/module/livepatch.c:58:
+    mod->klp_info->sechdrs[symndx].sh_addr = (unsigned long)
mod->core_kallsyms.symtab;

Ok.

Given how simple this function is, it should be a 'static inline' in
internal.c

Agreed.

CHECK: Alignment should match open parenthesis
#285: FILE: kernel/module/main.c:3033:
+    pr_err("%s: module is marked as livepatch module, but livepatch
support is disabled",
+        mod->name);

Fair enough.


Kind regards,

-- 
Aaron Tomlin