[GIT PULL] x86 fixes

[Ingo Molnar]

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);