On Mon, 11 Aug 2025 22:44:31 PDT (-0700), thomas.weissschuh@xxxxxxxxxxxxx wrote:
All the other architectures supporting LTO (x86, arm64, loongarch) do not use it for the vDSO. Its is problematic for some upcoming compile-time validation of the generated object code. The LTO object files do not contain the necessary relocation information and -flto-fat-objects is not compatible with clang < 16. For consistency and to enable the mentioned compile-time checks, disable LTO for the vDSO. The vDSO heavily uses __always_inline anyways. Signed-off-by: Thomas Weißschuh <thomas.weissschuh@xxxxxxxxxxxxx> Reviewed-by: Nathan Chancellor <nathan@xxxxxxxxxx> Tested-by: Jan Stancek <jstancek@xxxxxxxxxx> --- arch/riscv/kernel/vdso/Makefile | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/riscv/kernel/vdso/Makefile b/arch/riscv/kernel/vdso/Makefile index c19c3c76f7c9f6b2f7523a59269de3b683656323..9f1bf5bae9bd473e43d9fd3022e9e1a185128b73 100644 --- a/arch/riscv/kernel/vdso/Makefile +++ b/arch/riscv/kernel/vdso/Makefile @@ -49,7 +49,7 @@ CPPFLAGS_vdso.lds += -DHAS_VGETTIMEOFDAY endif # Disable -pg to prevent insert call site -CFLAGS_REMOVE_VDSO = $(CC_FLAGS_FTRACE) $(CC_FLAGS_SCS) +CFLAGS_REMOVE_VDSO = $(CC_FLAGS_FTRACE) $(CC_FLAGS_SCS) $(CC_FLAGS_LTO) CFLAGS_REMOVE_vgettimeofday.o = $(CFLAGS_REMOVE_VDSO) CFLAGS_REMOVE_getrandom.o = $(CFLAGS_REMOVE_VDSO) CFLAGS_REMOVE_hwprobe.o = $(CFLAGS_REMOVE_VDSO)
Acked-by: Palmer Dabbelt <palmer@xxxxxxxxxxx> Also assuming this goes with the others. Thanks!
