[GIT PULL] x86 fixes

From: Ingo Molnar
Date: Thu Sep 12 2019 - 08:57:16 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: afa8b475c1aec185a8e106c48b3832e0b88bc2de x86/timer: Force PIT initialization when !X86_FEATURE_ARAT

A KVM guest fix, and a kdump kernel relocation errors fix.

Thanks,

Ingo

------------------>
Jan Stancek (1):
x86/timer: Force PIT initialization when !X86_FEATURE_ARAT

Steve Wahl (1):
x86/purgatory: Change compiler flags from -mcmodel=kernel to -mcmodel=large to fix kexec relocation errors


arch/x86/kernel/apic/apic.c | 4 ++++
arch/x86/purgatory/Makefile | 35 +++++++++++++++++++----------------
2 files changed, 23 insertions(+), 16 deletions(-)

diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
index dba2828b779a..f91b3ff9dc03 100644
--- a/arch/x86/kernel/apic/apic.c
+++ b/arch/x86/kernel/apic/apic.c
@@ -834,6 +834,10 @@ bool __init apic_needs_pit(void)
if (!boot_cpu_has(X86_FEATURE_APIC))
return true;

+ /* Virt guests may lack ARAT, but still have DEADLINE */
+ if (!boot_cpu_has(X86_FEATURE_ARAT))
+ return true;
+
/* Deadline timer is based on TSC so no further PIT action required */
if (boot_cpu_has(X86_FEATURE_TSC_DEADLINE_TIMER))
return false;
diff --git a/arch/x86/purgatory/Makefile b/arch/x86/purgatory/Makefile
index 8901a1f89cf5..10fb42da0007 100644
--- a/arch/x86/purgatory/Makefile
+++ b/arch/x86/purgatory/Makefile
@@ -18,37 +18,40 @@ targets += purgatory.ro
KASAN_SANITIZE := n
KCOV_INSTRUMENT := n

+# These are adjustments to the compiler flags used for objects that
+# make up the standalone purgatory.ro
+
+PURGATORY_CFLAGS_REMOVE := -mcmodel=kernel
+PURGATORY_CFLAGS := -mcmodel=large -ffreestanding -fno-zero-initialized-in-bss
+
# Default KBUILD_CFLAGS can have -pg option set when FTRACE is enabled. That
# in turn leaves some undefined symbols like __fentry__ in purgatory and not
# sure how to relocate those.
ifdef CONFIG_FUNCTION_TRACER
-CFLAGS_REMOVE_sha256.o += $(CC_FLAGS_FTRACE)
-CFLAGS_REMOVE_purgatory.o += $(CC_FLAGS_FTRACE)
-CFLAGS_REMOVE_string.o += $(CC_FLAGS_FTRACE)
-CFLAGS_REMOVE_kexec-purgatory.o += $(CC_FLAGS_FTRACE)
+PURGATORY_CFLAGS_REMOVE += $(CC_FLAGS_FTRACE)
endif

ifdef CONFIG_STACKPROTECTOR
-CFLAGS_REMOVE_sha256.o += -fstack-protector
-CFLAGS_REMOVE_purgatory.o += -fstack-protector
-CFLAGS_REMOVE_string.o += -fstack-protector
-CFLAGS_REMOVE_kexec-purgatory.o += -fstack-protector
+PURGATORY_CFLAGS_REMOVE += -fstack-protector
endif

ifdef CONFIG_STACKPROTECTOR_STRONG
-CFLAGS_REMOVE_sha256.o += -fstack-protector-strong
-CFLAGS_REMOVE_purgatory.o += -fstack-protector-strong
-CFLAGS_REMOVE_string.o += -fstack-protector-strong
-CFLAGS_REMOVE_kexec-purgatory.o += -fstack-protector-strong
+PURGATORY_CFLAGS_REMOVE += -fstack-protector-strong
endif

ifdef CONFIG_RETPOLINE
-CFLAGS_REMOVE_sha256.o += $(RETPOLINE_CFLAGS)
-CFLAGS_REMOVE_purgatory.o += $(RETPOLINE_CFLAGS)
-CFLAGS_REMOVE_string.o += $(RETPOLINE_CFLAGS)
-CFLAGS_REMOVE_kexec-purgatory.o += $(RETPOLINE_CFLAGS)
+PURGATORY_CFLAGS_REMOVE += $(RETPOLINE_CFLAGS)
endif

+CFLAGS_REMOVE_purgatory.o += $(PURGATORY_CFLAGS_REMOVE)
+CFLAGS_purgatory.o += $(PURGATORY_CFLAGS)
+
+CFLAGS_REMOVE_sha256.o += $(PURGATORY_CFLAGS_REMOVE)
+CFLAGS_sha256.o += $(PURGATORY_CFLAGS)
+
+CFLAGS_REMOVE_string.o += $(PURGATORY_CFLAGS_REMOVE)
+CFLAGS_string.o += $(PURGATORY_CFLAGS)
+
$(obj)/purgatory.ro: $(PURGATORY_OBJS) FORCE
$(call if_changed,ld)