[thomas-weissschuh:b4/module-hashes 9/9] llvm-objcopy: error: '.tmp_module_hashes.o': The file was not recognized as a valid object file

[thomas-weissschuh:b4/module-hashes 9/9] llvm-objcopy: error: '.tmp_module_hashes.o': The file was not recognized as a valid object file

[kernel test robot]

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/thomas.weissschuh/linux.git b4/module-hashes
head:   8ab7849599f74e8492224b62d852cd9affecea7c
commit: 8ab7849599f74e8492224b62d852cd9affecea7c [9/9] module: Introduce hash-based integrity checking
config: x86_64-randconfig-005-20250311 (https://download.01.org/0day-ci/archive/20250311/202503112010.RsM1bgi6-lkp@intel.com/config)
compiler: clang version 19.1.7 (https://github.com/llvm/llvm-project cd708029e0b2869e80abe31ddb175f7c35361f90)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250311/202503112010.RsM1bgi6-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202503112010.RsM1bgi6-lkp@intel.com/

All errors (new ones prefixed by >>):

>> llvm-objcopy: error: '.tmp_module_hashes.o': The file was not recognized as a valid object file

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

Re: [thomas-weissschuh:b4/module-hashes 9/9] llvm-objcopy: error: '.tmp_module_hashes.o': The file was not recognized as a valid object file

[Nathan Chancellor]

On Tue, Mar 11, 2025 at 08:14:14PM +0800, kernel test robot wrote:
> tree:   https://git.kernel.org/pub/scm/linux/kernel/git/thomas.weissschuh/linux.git b4/module-hashes
> head:   8ab7849599f74e8492224b62d852cd9affecea7c
> commit: 8ab7849599f74e8492224b62d852cd9affecea7c [9/9] module: Introduce hash-based integrity checking
> config: x86_64-randconfig-005-20250311 (https://download.01.org/0day-ci/archive/20250311/202503112010.RsM1bgi6-lkp@intel.com/config)
> compiler: clang version 19.1.7 (https://github.com/llvm/llvm-project cd708029e0b2869e80abe31ddb175f7c35361f90)
> reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250311/202503112010.RsM1bgi6-lkp@intel.com/reproduce)
> 
> If you fix the issue in a separate patch/commit (i.e. not just a new version of
> the same patch/commit), kindly add following tags
> | Reported-by: kernel test robot <lkp@intel.com>
> | Closes: https://lore.kernel.org/oe-kbuild-all/202503112010.RsM1bgi6-lkp@intel.com/
> 
> All errors (new ones prefixed by >>):
> 
> >> llvm-objcopy: error: '.tmp_module_hashes.o': The file was not recognized as a valid object file

I suspect this happens because LTO is enabled for this configuration (so
-flto will be in KBUILD_CFLAGS), which generates an LLVM bitcode object
file instead of an ELF one.

Cheers,
Nathan

Re: [thomas-weissschuh:b4/module-hashes 9/9] llvm-objcopy: error: '.tmp_module_hashes.o': The file was not recognized as a valid object file

[Thomas Weißschuh]

Hi Nathan,

On 2025-03-11 20:49:40+0100, Nathan Chancellor wrote:
> On Tue, Mar 11, 2025 at 08:14:14PM +0800, kernel test robot wrote:
> > tree:   https://git.kernel.org/pub/scm/linux/kernel/git/thomas.weissschuh/linux.git b4/module-hashes
> > head:   8ab7849599f74e8492224b62d852cd9affecea7c
> > commit: 8ab7849599f74e8492224b62d852cd9affecea7c [9/9] module: Introduce hash-based integrity checking
> > config: x86_64-randconfig-005-20250311 (https://download.01.org/0day-ci/archive/20250311/202503112010.RsM1bgi6-lkp@intel.com/config)
> > compiler: clang version 19.1.7 (https://github.com/llvm/llvm-project cd708029e0b2869e80abe31ddb175f7c35361f90)
> > reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250311/202503112010.RsM1bgi6-lkp@intel.com/reproduce)
> > 
> > If you fix the issue in a separate patch/commit (i.e. not just a new version of
> > the same patch/commit), kindly add following tags
> > | Reported-by: kernel test robot <lkp@intel.com>
> > | Closes: https://lore.kernel.org/oe-kbuild-all/202503112010.RsM1bgi6-lkp@intel.com/
> > 
> > All errors (new ones prefixed by >>):
> > 
> > >> llvm-objcopy: error: '.tmp_module_hashes.o': The file was not recognized as a valid object file
> 
> I suspect this happens because LTO is enabled for this configuration (so
> -flto will be in KBUILD_CFLAGS), which generates an LLVM bitcode object
> file instead of an ELF one.

Thanks for the hint!

The following diff seems to fix the issue and quick testing indicates
that it should work with the different supported compilers.
Any objections?

diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh
index 2add7eb950a0..f8d87a2ae74b 100755
--- a/scripts/link-vmlinux.sh
+++ b/scripts/link-vmlinux.sh
@@ -324,7 +324,7 @@ if is_enabled CONFIG_MODULE_HASHES; then
        ${srctree}/scripts/module-hashes.sh > .tmp_module_hashes.c
        info CC ${module_hashes_o}
        ${CC} ${NOSTDINC_FLAGS} ${LINUXINCLUDE} ${KBUILD_CPPFLAGS} ${KBUILD_CFLAGS} \
-               ${KBUILD_CFLAGS_KERNEL} -c -o "${module_hashes_o}" ".tmp_module_hashes.c"
+               ${KBUILD_CFLAGS_KERNEL} -fno-lto -c -o "${module_hashes_o}" ".tmp_module_hashes.c"
        ${OBJCOPY} --dump-section .module_hashes=.tmp_module_hashes.bin ${module_hashes_o}
        ${OBJCOPY} --update-section .module_hashes=.tmp_module_hashes.bin vmlinux
 fi

Re: [thomas-weissschuh:b4/module-hashes 9/9] llvm-objcopy: error: '.tmp_module_hashes.o': The file was not recognized as a valid object file

[Nathan Chancellor]

On Tue, Mar 11, 2025 at 09:58:06PM +0100, Thomas Weißschuh wrote:
> Hi Nathan,
> 
> On 2025-03-11 20:49:40+0100, Nathan Chancellor wrote:
> > On Tue, Mar 11, 2025 at 08:14:14PM +0800, kernel test robot wrote:
> > > tree:   https://git.kernel.org/pub/scm/linux/kernel/git/thomas.weissschuh/linux.git b4/module-hashes
> > > head:   8ab7849599f74e8492224b62d852cd9affecea7c
> > > commit: 8ab7849599f74e8492224b62d852cd9affecea7c [9/9] module: Introduce hash-based integrity checking
> > > config: x86_64-randconfig-005-20250311 (https://download.01.org/0day-ci/archive/20250311/202503112010.RsM1bgi6-lkp@intel.com/config)
> > > compiler: clang version 19.1.7 (https://github.com/llvm/llvm-project cd708029e0b2869e80abe31ddb175f7c35361f90)
> > > reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250311/202503112010.RsM1bgi6-lkp@intel.com/reproduce)
> > > 
> > > If you fix the issue in a separate patch/commit (i.e. not just a new version of
> > > the same patch/commit), kindly add following tags
> > > | Reported-by: kernel test robot <lkp@intel.com>
> > > | Closes: https://lore.kernel.org/oe-kbuild-all/202503112010.RsM1bgi6-lkp@intel.com/
> > > 
> > > All errors (new ones prefixed by >>):
> > > 
> > > >> llvm-objcopy: error: '.tmp_module_hashes.o': The file was not recognized as a valid object file
> > 
> > I suspect this happens because LTO is enabled for this configuration (so
> > -flto will be in KBUILD_CFLAGS), which generates an LLVM bitcode object
> > file instead of an ELF one.
> 
> Thanks for the hint!
> 
> The following diff seems to fix the issue and quick testing indicates
> that it should work with the different supported compilers.
> Any objections?

Nope, I think that should work fine.

> diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh
> index 2add7eb950a0..f8d87a2ae74b 100755
> --- a/scripts/link-vmlinux.sh
> +++ b/scripts/link-vmlinux.sh
> @@ -324,7 +324,7 @@ if is_enabled CONFIG_MODULE_HASHES; then
>         ${srctree}/scripts/module-hashes.sh > .tmp_module_hashes.c
>         info CC ${module_hashes_o}
>         ${CC} ${NOSTDINC_FLAGS} ${LINUXINCLUDE} ${KBUILD_CPPFLAGS} ${KBUILD_CFLAGS} \
> -               ${KBUILD_CFLAGS_KERNEL} -c -o "${module_hashes_o}" ".tmp_module_hashes.c"
> +               ${KBUILD_CFLAGS_KERNEL} -fno-lto -c -o "${module_hashes_o}" ".tmp_module_hashes.c"
>         ${OBJCOPY} --dump-section .module_hashes=.tmp_module_hashes.bin ${module_hashes_o}
>         ${OBJCOPY} --update-section .module_hashes=.tmp_module_hashes.bin vmlinux
>  fi