On 9/17/25 7:03 PM, Josh Poimboeuf wrote:
In preparation for the objtool klp diff subcommand, remove the arbitrary
'kmod_' prefix from __KBUILD_MODNAME and instead add it explicitly in
the __initcall_id() macro.
This change supports the standardization of "unique" symbol naming by
ensuring the non-unique portion of the name comes before the unique
part. That will enable objtool to properly correlate symbols across
builds.
Cc: Masahiro Yamada <[email protected]>
Signed-off-by: Josh Poimboeuf <[email protected]>
---
include/linux/init.h | 3 ++-
scripts/Makefile.lib | 2 +-
2 files changed, 3 insertions(+), 2 deletions(-)
diff --git a/include/linux/init.h b/include/linux/init.h
index 17c1bc712e234..40331923b9f4a 100644
--- a/include/linux/init.h
+++ b/include/linux/init.h
@@ -200,12 +200,13 @@ extern struct module __this_module;
/* Format: <modname>__<counter>_<line>_<fn> */
#define __initcall_id(fn) \
+ __PASTE(kmod_, \
__PASTE(__KBUILD_MODNAME, \
__PASTE(__, \
__PASTE(__COUNTER__, \
__PASTE(_, \
__PASTE(__LINE__, \
- __PASTE(_, fn))))))
+ __PASTE(_, fn)))))))
/* Format: __<prefix>__<iid><id> */
#define __initcall_name(prefix, __iid, id) \
diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
index 1d581ba5df66f..b955602661240 100644
--- a/scripts/Makefile.lib
+++ b/scripts/Makefile.lib
@@ -20,7 +20,7 @@ name-fix-token = $(subst $(comma),_,$(subst -,_,$1))
name-fix = $(call stringify,$(call name-fix-token,$1))
basename_flags = -DKBUILD_BASENAME=$(call name-fix,$(basetarget))
modname_flags = -DKBUILD_MODNAME=$(call name-fix,$(modname)) \
- -D__KBUILD_MODNAME=kmod_$(call name-fix-token,$(modname))
+ -D__KBUILD_MODNAME=$(call name-fix-token,$(modname))
As others have mentioned, this breaks modules.alias generation.
The following diff seems to fix it, although in introduces a slight
functional change if symbols do not actually follow the naming scheme.
diff --git a/scripts/mod/file2alias.c b/scripts/mod/file2alias.c
index b3333560b95e..c3c06b944c69 100644
--- a/scripts/mod/file2alias.c
+++ b/scripts/mod/file2alias.c
@@ -1489,14 +1489,11 @@ void handle_moddevtable(struct module *mod,
struct elf_info *info,
if (ELF_ST_TYPE(sym->st_info) != STT_OBJECT)
return;
- /* All our symbols are of form
__mod_device_table__kmod_<modname>__<type>__<name>. */
+ /* All our symbols are of form
__mod_device_table__<modname>__<type>__<name>. */
if (!strstarts(symname, prefix))
return;
- modname = strstr(symname, "__kmod_");
- if (!modname)
- return;
- modname += strlen("__kmod_");
+ modname = symname + strlen(prefix);
type = strstr(modname, "__");
if (!type)
It would seem like rust generated symbols don't follow it exactly?
See module_device_table macro in rust/kernel/device_id.rs.
modfile_flags = -DKBUILD_MODFILE=$(call stringify,$(modfile))
_c_flags = $(filter-out $(CFLAGS_REMOVE_$(target-stem).o), \
