From a26a6c93edfeee82cb73f55e87d995eea59ddfe8 Mon Sep 17 00:00:00 2001 From: Nathan Chancellor Date: Wed, 5 Nov 2025 15:30:27 -0700 Subject: [PATCH 1/3] kbuild: Strip trailing padding bytes from modules.builtin.modinfo After commit d50f21091358 ("kbuild: align modinfo section for Secureboot Authenticode EDK2 compat"), running modules_install with certain versions of kmod (such as 29.1 in Ubuntu Jammy) in certain configurations may fail with: depmod: ERROR: kmod_builtin_iter_next: unexpected string without modname prefix The additional padding bytes to ensure .modinfo is aligned within vmlinux.unstripped are unexpected by kmod, as this section has always just been null-terminated strings. Strip the trailing padding bytes from modules.builtin.modinfo after it has been extracted from vmlinux.unstripped to restore the format that kmod expects while keeping .modinfo aligned within vmlinux.unstripped to avoid regressing the Authenticode calculation fix for EDK2. Cc: stable@vger.kernel.org Fixes: d50f21091358 ("kbuild: align modinfo section for Secureboot Authenticode EDK2 compat") Reported-by: Omar Sandoval Reported-by: Samir M Reported-by: Venkat Rao Bagalkote Closes: https://lore.kernel.org/7fef7507-ad64-4e51-9bb8-c9fb6532e51e@linux.ibm.com/ Tested-by: Omar Sandoval Tested-by: Samir M Tested-by: Venkat Rao Bagalkote Reviewed-by: Nicolas Schier Link: https://patch.msgid.link/20251105-kbuild-fix-builtin-modinfo-for-kmod-v1-1-b419d8ad4606@kernel.org Signed-off-by: Nathan Chancellor --- scripts/Makefile.vmlinux | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-) diff --git a/scripts/Makefile.vmlinux b/scripts/Makefile.vmlinux index ced4379550d7..cd788cac9d91 100644 --- a/scripts/Makefile.vmlinux +++ b/scripts/Makefile.vmlinux @@ -102,11 +102,24 @@ vmlinux: vmlinux.unstripped FORCE # modules.builtin.modinfo # --------------------------------------------------------------------------- +# .modinfo in vmlinux.unstripped is aligned to 8 bytes for compatibility with +# tools that expect vmlinux to have sufficiently aligned sections but the +# additional bytes used for padding .modinfo to satisfy this requirement break +# certain versions of kmod with +# +# depmod: ERROR: kmod_builtin_iter_next: unexpected string without modname prefix +# +# Strip the trailing padding bytes after extracting .modinfo to comply with +# what kmod expects to parse. +quiet_cmd_modules_builtin_modinfo = GEN $@ + cmd_modules_builtin_modinfo = $(cmd_objcopy); \ + sed -i 's/\x00\+$$/\x00/g' $@ + OBJCOPYFLAGS_modules.builtin.modinfo := -j .modinfo -O binary targets += modules.builtin.modinfo modules.builtin.modinfo: vmlinux.unstripped FORCE - $(call if_changed,objcopy) + $(call if_changed,modules_builtin_modinfo) # modules.builtin # --------------------------------------------------------------------------- From 9818af18db4bfefd320d0fef41390a616365e6f7 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Thu, 6 Nov 2025 11:50:00 +0100 Subject: [PATCH 2/3] compiler_types: Move unused static inline functions warning to W=2 Per Nathan, clang catches unused "static inline" functions in C files since commit 6863f5643dd7 ("kbuild: allow Clang to find unused static inline functions for W=1 build"). Linus said: > So I entirely ignore W=1 issues, because I think so many of the extra > warnings are bogus. > > But if this one in particular is causing more problems than most - > some teams do seem to use W=1 as part of their test builds - it's fine > to send me a patch that just moves bad warnings to W=2. > > And if anybody uses W=2 for their test builds, that's THEIR problem.. Here is the change to bump the warning from W=1 to W=2. Fixes: 6863f5643dd7 ("kbuild: allow Clang to find unused static inline functions for W=1 build") Signed-off-by: Peter Zijlstra Signed-off-by: Andy Shevchenko Link: https://patch.msgid.link/20251106105000.2103276-1-andriy.shevchenko@linux.intel.com [nathan: Adjust comment as well] Signed-off-by: Nathan Chancellor --- include/linux/compiler_types.h | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/include/linux/compiler_types.h b/include/linux/compiler_types.h index 59288a2c1ad2..339603f05b54 100644 --- a/include/linux/compiler_types.h +++ b/include/linux/compiler_types.h @@ -250,10 +250,9 @@ struct ftrace_likely_data { /* * GCC does not warn about unused static inline functions for -Wunused-function. * Suppress the warning in clang as well by using __maybe_unused, but enable it - * for W=1 build. This will allow clang to find unused functions. Remove the - * __inline_maybe_unused entirely after fixing most of -Wunused-function warnings. + * for W=2 build. This will allow clang to find unused functions. */ -#ifdef KBUILD_EXTRA_WARN1 +#ifdef KBUILD_EXTRA_WARN2 #define __inline_maybe_unused #else #define __inline_maybe_unused __maybe_unused From 002621a4df3c166fab1427e8e502bc15acc26b13 Mon Sep 17 00:00:00 2001 From: Jean Delvare Date: Fri, 7 Nov 2025 19:29:33 +0100 Subject: [PATCH 3/3] kbuild: Let kernel-doc.py use PYTHON3 override It is possible to force a specific version of python to be used when building the kernel by passing PYTHON3= on the make command line. However kernel-doc.py is currently called with python3 hard-coded and thus ignores this setting. Use $(PYTHON3) to run $(KERNELDOC) so that the desired version of python is used. Signed-off-by: Jean Delvare Reviewed-by: Nicolas Schier Reviewed-by: Mauro Carvalho Chehab Link: https://patch.msgid.link/20251107192933.2bfe9e57@endymion Signed-off-by: Nathan Chancellor --- drivers/gpu/drm/Makefile | 2 +- drivers/gpu/drm/i915/Makefile | 2 +- include/drm/Makefile | 2 +- scripts/Makefile.build | 2 +- 4 files changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile index 4b2f7d794275..da2565e6de71 100644 --- a/drivers/gpu/drm/Makefile +++ b/drivers/gpu/drm/Makefile @@ -245,7 +245,7 @@ always-$(CONFIG_DRM_HEADER_TEST) += \ quiet_cmd_hdrtest = HDRTEST $(patsubst %.hdrtest,%.h,$@) cmd_hdrtest = \ $(CC) $(c_flags) -fsyntax-only -x c /dev/null -include $< -include $<; \ - PYTHONDONTWRITEBYTECODE=1 $(KERNELDOC) -none $(if $(CONFIG_WERROR)$(CONFIG_DRM_WERROR),-Werror) $<; \ + PYTHONDONTWRITEBYTECODE=1 $(PYTHON3) $(KERNELDOC) -none $(if $(CONFIG_WERROR)$(CONFIG_DRM_WERROR),-Werror) $<; \ touch $@ $(obj)/%.hdrtest: $(src)/%.h FORCE diff --git a/drivers/gpu/drm/i915/Makefile b/drivers/gpu/drm/i915/Makefile index e58c0c158b3a..b91575380708 100644 --- a/drivers/gpu/drm/i915/Makefile +++ b/drivers/gpu/drm/i915/Makefile @@ -413,7 +413,7 @@ obj-$(CONFIG_DRM_I915_GVT_KVMGT) += kvmgt.o # # Enable locally for CONFIG_DRM_I915_WERROR=y. See also scripts/Makefile.build ifdef CONFIG_DRM_I915_WERROR - cmd_checkdoc = PYTHONDONTWRITEBYTECODE=1 $(KERNELDOC) -none -Werror $< + cmd_checkdoc = PYTHONDONTWRITEBYTECODE=1 $(PYTHON3) $(KERNELDOC) -none -Werror $< endif # header test diff --git a/include/drm/Makefile b/include/drm/Makefile index 1df6962556ef..48fae3f167c7 100644 --- a/include/drm/Makefile +++ b/include/drm/Makefile @@ -11,7 +11,7 @@ always-$(CONFIG_DRM_HEADER_TEST) += \ quiet_cmd_hdrtest = HDRTEST $(patsubst %.hdrtest,%.h,$@) cmd_hdrtest = \ $(CC) $(c_flags) -fsyntax-only -x c /dev/null -include $< -include $<; \ - PYTHONDONTWRITEBYTECODE=1 $(KERNELDOC) -none $(if $(CONFIG_WERROR)$(CONFIG_DRM_WERROR),-Werror) $<; \ + PYTHONDONTWRITEBYTECODE=1 $(PYTHON3) $(KERNELDOC) -none $(if $(CONFIG_WERROR)$(CONFIG_DRM_WERROR),-Werror) $<; \ touch $@ $(obj)/%.hdrtest: $(src)/%.h FORCE diff --git a/scripts/Makefile.build b/scripts/Makefile.build index d0ee33a487be..52c08c4eb0b9 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -167,7 +167,7 @@ else ifeq ($(KBUILD_CHECKSRC),2) endif ifneq ($(KBUILD_EXTRA_WARN),) - cmd_checkdoc = PYTHONDONTWRITEBYTECODE=1 $(KERNELDOC) -none $(KDOCFLAGS) \ + cmd_checkdoc = PYTHONDONTWRITEBYTECODE=1 $(PYTHON3) $(KERNELDOC) -none $(KDOCFLAGS) \ $(if $(findstring 2, $(KBUILD_EXTRA_WARN)), -Wall) \ $< endif