[GIT PULL] x86 fixes

From: Ingo Molnar
Date: Sun Dec 09 2018 - 17:07:06 EST


Linus,

Please pull the latest x86-urgent-for-linus git tree from:

git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git x86-urgent-for-linus

# HEAD: ac3e233d29f7f77f28243af0132057d378d3ea58 x86/vdso: Drop implicit common-page-size linker flag

Three fixes: a boot parameter re-(re-)fix, a retpoline build artifact fix
and an LLVM workaround.

Thanks,

Ingo

------------------>
Juergen Gross (1):
x86/boot: Clear RSDP address in boot_params for broken loaders

Masahiro Yamada (1):
x86/build: Fix compiler support check for CONFIG_RETPOLINE

Nick Desaulniers (1):
x86/vdso: Drop implicit common-page-size linker flag


arch/x86/Makefile | 10 +++++++---
arch/x86/entry/vdso/Makefile | 4 ++--
arch/x86/include/asm/bootparam_utils.h | 1 +
3 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/arch/x86/Makefile b/arch/x86/Makefile
index f5d7f4134524..75ef499a66e2 100644
--- a/arch/x86/Makefile
+++ b/arch/x86/Makefile
@@ -220,9 +220,6 @@ KBUILD_CFLAGS += -fno-asynchronous-unwind-tables

# Avoid indirect branches in kernel to deal with Spectre
ifdef CONFIG_RETPOLINE
-ifeq ($(RETPOLINE_CFLAGS),)
- $(error You are building kernel with non-retpoline compiler, please update your compiler.)
-endif
KBUILD_CFLAGS += $(RETPOLINE_CFLAGS)
endif

@@ -307,6 +304,13 @@ ifndef CC_HAVE_ASM_GOTO
@echo Compiler lacks asm-goto support.
@exit 1
endif
+ifdef CONFIG_RETPOLINE
+ifeq ($(RETPOLINE_CFLAGS),)
+ @echo "You are building kernel with non-retpoline compiler." >&2
+ @echo "Please update your compiler." >&2
+ @false
+endif
+endif

archclean:
$(Q)rm -rf $(objtree)/arch/i386
diff --git a/arch/x86/entry/vdso/Makefile b/arch/x86/entry/vdso/Makefile
index 141d415a8c80..0624bf2266fd 100644
--- a/arch/x86/entry/vdso/Makefile
+++ b/arch/x86/entry/vdso/Makefile
@@ -47,7 +47,7 @@ targets += $(vdso_img_sodbg) $(vdso_img-y:%=vdso%.so)
CPPFLAGS_vdso.lds += -P -C

VDSO_LDFLAGS_vdso.lds = -m elf_x86_64 -soname linux-vdso.so.1 --no-undefined \
- -z max-page-size=4096 -z common-page-size=4096
+ -z max-page-size=4096

$(obj)/vdso64.so.dbg: $(obj)/vdso.lds $(vobjs) FORCE
$(call if_changed,vdso)
@@ -98,7 +98,7 @@ CFLAGS_REMOVE_vvar.o = -pg

CPPFLAGS_vdsox32.lds = $(CPPFLAGS_vdso.lds)
VDSO_LDFLAGS_vdsox32.lds = -m elf32_x86_64 -soname linux-vdso.so.1 \
- -z max-page-size=4096 -z common-page-size=4096
+ -z max-page-size=4096

# x32-rebranded versions
vobjx32s-y := $(vobjs-y:.o=-x32.o)
diff --git a/arch/x86/include/asm/bootparam_utils.h b/arch/x86/include/asm/bootparam_utils.h
index a07ffd23e4dd..f6f6ef436599 100644
--- a/arch/x86/include/asm/bootparam_utils.h
+++ b/arch/x86/include/asm/bootparam_utils.h
@@ -36,6 +36,7 @@ static void sanitize_boot_params(struct boot_params *boot_params)
*/
if (boot_params->sentinel) {
/* fields in boot_params are left uninitialized, clear them */
+ boot_params->acpi_rsdp_addr = 0;
memset(&boot_params->ext_ramdisk_image, 0,
(char *)&boot_params->efi_info -
(char *)&boot_params->ext_ramdisk_image);