On 5/9/25 4:17 PM, Josh Poimboeuf wrote:
> In preparation for the objtool klp diff subcommand, defer objtool
> validation for CONFIG_LIVEPATCH until the final pre-link archive (e.g.,
> vmlinux.o, module-foo.o) is built. This will simplify the process of
> generating livepatch modules.
>
> Delayed objtool is generally preferred anyway, and is already standard
> for IBT and LTO. Eventually the per-translation-unit mode will be
> phased out.
>
> Signed-off-by: Josh Poimboeuf <[email protected]>
> ---
> scripts/Makefile.lib | 2 +-
> scripts/link-vmlinux.sh | 3 ++-
> 2 files changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
> index bfd55a6ad8f1..a68390ff5cd9 100644
> --- a/scripts/Makefile.lib
> +++ b/scripts/Makefile.lib
> @@ -278,7 +278,7 @@ objtool-args = $(objtool-args-y)
> \
> $(if $(delay-objtool), --link) \
> $(if $(part-of-module), --module)
>
> -delay-objtool := $(or $(CONFIG_LTO_CLANG),$(CONFIG_X86_KERNEL_IBT))
> +delay-objtool := $(or
> $(CONFIG_LTO_CLANG),$(CONFIG_X86_KERNEL_IBT),$(CONFIG_LIVEPATCH))
>
> cmd_objtool = $(if $(objtool-enabled), ; $(objtool) $(objtool-args) $@)
> cmd_gen_objtooldep = $(if $(objtool-enabled), { echo ; echo '$@: $$(wildcard
> $(objtool))' ; } >> $(dot-target).cmd)
> diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh
> index 51367c2bfc21..acffa3c935f2 100755
> --- a/scripts/link-vmlinux.sh
> +++ b/scripts/link-vmlinux.sh
> @@ -60,7 +60,8 @@ vmlinux_link()
> # skip output file argument
> shift
>
> - if is_enabled CONFIG_LTO_CLANG || is_enabled CONFIG_X86_KERNEL_IBT; then
> + if is_enabled CONFIG_LTO_CLANG || is_enabled CONFIG_X86_KERNEL_IBT ||
> + is_enabled CONFIG_LIVEPATCH; then
> # Use vmlinux.o instead of performing the slow LTO link again.
> objs=vmlinux.o
> libs=
At this commit, I'm getting the following linker error on ppc64le:
ld -EL -m elf64lppc -z noexecstack --no-warn-rwx-segments -pie -z notext
--build-id=sha1 -X --orphan-handling=error
--script=./arch/powerpc/kernel/vmlinux.lds -o .tmp_vmlinux1
--whole-archive vmlinux.o .vmlinux.export.o init/version-timestamp.o
--no-whole-archive --start-group --end-group .tmp_vmlinux0.kallsyms.o
arch/powerpc/tools/vmlinux.arch.o
vmlinux.o:(__ftr_alt_97+0x20): relocation truncated to fit:
R_PPC64_REL14 against `.text'+4b54
vmlinux.o:(__ftr_alt_97+0x270): relocation truncated to fit:
R_PPC64_REL14 against `.text'+173ecc
* Note: I dropped ("[PATCH v2 45/62] x86/extable: Define ELF section
entry size for exception tables") since it doesn't build as per the
comment I left on that patch.
--
Joe
