diff -up ./arch/x86/kernel/cpu/common.c.spec2 ./arch/x86/kernel/cpu/common.c
--- ./arch/x86/kernel/cpu/common.c.spec2	2018-05-16 06:03:51.000000000 +0900
+++ ./arch/x86/kernel/cpu/common.c	2018-05-29 20:03:08.000000000 +0900
@@ -1441,6 +1442,9 @@ DEFINE_PER_CPU(struct task_struct *, fpu
 DEFINE_PER_CPU_ALIGNED(struct stack_canary, stack_canary);
 #endif
 
+DEFINE_PER_CPU_USER_MAPPED(struct kernel_ibrs_spec_ctrl, spec_ctrl_pcp);
+EXPORT_PER_CPU_SYMBOL_GPL(spec_ctrl_pcp);
+
 #endif	/* CONFIG_X86_64 */
 
 /*
diff -up ./arch/x86/kernel/reboot.c.spec2 ./arch/x86/kernel/reboot.c
--- ./arch/x86/kernel/reboot.c.spec2	2018-05-16 06:03:51.000000000 +0900
+++ ./arch/x86/kernel/reboot.c	2018-05-29 20:03:08.000000000 +0900
@@ -23,6 +23,7 @@
 #include <asm/cpu.h>
 #include <asm/nmi.h>
 #include <asm/smp.h>
+#include <asm/mmu_context.h>
 
 #include <linux/ctype.h>
 #include <linux/mc146818rtc.h>
diff -up ./arch/x86/kernel/smpboot.c.spec2 ./arch/x86/kernel/smpboot.c
--- ./arch/x86/kernel/smpboot.c.spec2	2018-05-16 06:03:51.000000000 +0900
+++ ./arch/x86/kernel/smpboot.c	2018-05-29 20:03:08.000000000 +0900
@@ -72,6 +72,7 @@
 #include <asm/fpu-internal.h>
 #include <asm/setup.h>
 #include <asm/uv/uv.h>
+#include <asm/mmu_context.h>
 #include <linux/mc146818rtc.h>
 
 #include <asm/smpboot_hooks.h>
diff -up ./arch/x86/platform/efi/efi_32.c.spec2 ./arch/x86/platform/efi/efi_32.c
--- ./arch/x86/platform/efi/efi_32.c.spec2	2018-05-16 06:03:51.000000000 +0900
+++ ./arch/x86/platform/efi/efi_32.c	2018-05-29 20:03:08.000000000 +0900
@@ -30,6 +30,7 @@
 #include <asm/pgtable.h>
 #include <asm/tlbflush.h>
 #include <asm/efi.h>
+#include <asm/mmu_context.h>
 
 /*
  * To make EFI call EFI runtime service in physical addressing mode we need

https://bugs.centos.org/view.php?id=14597
https://bugs.centos.org/file_download.php?file_id=23451&type=bug

diff -up ./arch/x86/kernel/cpu/bugs.c.fpu2 ./arch/x86/kernel/cpu/bugs.c
--- ./arch/x86/kernel/cpu/bugs.c.fpu2	2018-05-28 21:40:16.000000000 +0900
+++ ./arch/x86/kernel/cpu/bugs.c	2018-05-28 21:40:25.000000000 +0900
@@ -25,6 +25,70 @@
 #include <asm/spec_ctrl.h>
 #include <linux/prctl.h>
 
+static int __init no_387(char *s)
+{
+	boot_cpu_data.hard_math = 0;
+	write_cr0(X86_CR0_TS | X86_CR0_EM | X86_CR0_MP | read_cr0());
+	return 1;
+}
+
+__setup("no387", no_387);
+
+static double __initdata x = 4195835.0;
+static double __initdata y = 3145727.0;
+
+/*
+ * This used to check for exceptions..
+ * However, it turns out that to support that,
+ * the XMM trap handlers basically had to
+ * be buggy. So let's have a correct XMM trap
+ * handler, and forget about printing out
+ * some status at boot.
+ *
+ * We should really only care about bugs here
+ * anyway. Not features.
+ */
+static void __init check_fpu(void)
+{
+	s32 fdiv_bug;
+
+	if (!boot_cpu_data.hard_math) {
+#ifndef CONFIG_MATH_EMULATION
+		pr_emerg("No coprocessor found and no math emulation present\n");
+		pr_emerg("Giving up\n");
+		for (;;) ;
+#endif
+		return;
+	}
+
+	kernel_fpu_begin();
+
+	/*
+	 * trap_init() enabled FXSR and company _before_ testing for FP
+	 * problems here.
+	 *
+	 * Test for the divl bug: http://en.wikipedia.org/wiki/Fdiv_bug
+	 */
+	__asm__("fninit\n\t"
+		"fldl %1\n\t"
+		"fdivl %2\n\t"
+		"fmull %2\n\t"
+		"fldl %1\n\t"
+		"fsubp %%st,%%st(1)\n\t"
+		"fistpl %0\n\t"
+		"fwait\n\t"
+		"fninit"
+		: "=m" (*&fdiv_bug)
+		: "m" (*&x), "m" (*&y));
+
+	kernel_fpu_end();
+
+	if (fdiv_bug) {
+		set_cpu_bug(&boot_cpu_data, X86_BUG_FDIV);
+		pr_warn("Hmm, FPU with FDIV bug\n");
+	}
+}
+
 static void __init spectre_v2_select_mitigation(void);
 static void __init ssb_parse_cmdline(void);
 void ssb_select_mitigation(void);
@@ -426,8 +490,10 @@ ssize_t cpu_show_meltdown(struct device
 {
 	if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD)
 		return sprintf(buf, "Not affected\n");
+#ifdef CONFIG_KAISER
 	if (kaiser_enabled)
 		return sprintf(buf, "Mitigation: PTI\n");
+#endif
 	return sprintf(buf, "Vulnerable\n");
 }