diff options
Diffstat (limited to 'arch/x86/Makefile')
| -rw-r--r-- | arch/x86/Makefile | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/arch/x86/Makefile b/arch/x86/Makefile index 9c5a67d1b9c1..2d8b9d8ca4f8 100644 --- a/arch/x86/Makefile +++ b/arch/x86/Makefile @@ -187,7 +187,6 @@ cfi-sigframe := $(call as-instr,.cfi_startproc\n.cfi_signal_frame\n.cfi_endproc, cfi-sections := $(call as-instr,.cfi_sections .debug_frame,-DCONFIG_AS_CFI_SECTIONS=1) # does binutils support specific instructions? -asinstr := $(call as-instr,fxsaveq (%rax),-DCONFIG_AS_FXSAVEQ=1) asinstr += $(call as-instr,pshufb %xmm0$(comma)%xmm0,-DCONFIG_AS_SSSE3=1) avx_instr := $(call as-instr,vxorps %ymm0$(comma)%ymm1$(comma)%ymm2,-DCONFIG_AS_AVX=1) avx2_instr :=$(call as-instr,vpbroadcastb %xmm0$(comma)%ymm1,-DCONFIG_AS_AVX2=1) @@ -217,6 +216,11 @@ KBUILD_CFLAGS += -fno-asynchronous-unwind-tables # Avoid indirect branches in kernel to deal with Spectre ifdef CONFIG_RETPOLINE KBUILD_CFLAGS += $(RETPOLINE_CFLAGS) + # Additionally, avoid generating expensive indirect jumps which + # are subject to retpolines for small number of switch cases. + # clang turns off jump table generation by default when under + # retpoline builds, however, gcc does not for x86. + KBUILD_CFLAGS += $(call cc-option,--param=case-values-threshold=20) endif archscripts: scripts_basic |