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authorDmitry Torokhov <dmitry.torokhov@gmail.com>2019-07-10 23:24:10 -0700
committerDmitry Torokhov <dmitry.torokhov@gmail.com>2019-07-10 23:24:10 -0700
commit597473720f4dc69749542bfcfed4a927a43d935e (patch)
tree711bf773910fb93d1dd9120c633adc807685e0d8 /arch/x86/Makefile
parentInput: atmel_mxt_ts - fix leak in mxt_update_cfg() (diff)
parentInput: gpio_keys_polled - allow specifying name of input device (diff)
downloadlinux-dev-597473720f4dc69749542bfcfed4a927a43d935e.tar.xz
linux-dev-597473720f4dc69749542bfcfed4a927a43d935e.zip
Merge branch 'next' into for-linus
Prepare input updates for 5.3 merge window.
Diffstat (limited to 'arch/x86/Makefile')
-rw-r--r--arch/x86/Makefile16
1 files changed, 10 insertions, 6 deletions
diff --git a/arch/x86/Makefile b/arch/x86/Makefile
index 85a66c4a8b65..a587805c6687 100644
--- a/arch/x86/Makefile
+++ b/arch/x86/Makefile
@@ -130,10 +130,6 @@ else
KBUILD_CFLAGS += -mno-red-zone
KBUILD_CFLAGS += -mcmodel=kernel
-
- # -funit-at-a-time shrinks the kernel .text considerably
- # unfortunately it makes reading oopses harder.
- KBUILD_CFLAGS += $(call cc-option,-funit-at-a-time)
endif
ifdef CONFIG_X86_X32
@@ -191,7 +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)
@@ -221,6 +216,15 @@ 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. This has
+ # only been fixed starting from gcc stable version 8.4.0 and
+ # onwards, but not for older ones. See gcc bug #86952.
+ ifndef CONFIG_CC_IS_CLANG
+ KBUILD_CFLAGS += $(call cc-option,-fno-jump-tables)
+ endif
endif
archscripts: scripts_basic
@@ -293,7 +297,7 @@ vdso_install:
archprepare: checkbin
checkbin:
-ifndef CC_HAVE_ASM_GOTO
+ifndef CONFIG_CC_HAS_ASM_GOTO
@echo Compiler lacks asm-goto support.
@exit 1
endif