1 files changed, 39 insertions, 22 deletions

diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 9cfca3d7d0e2..65ceabb2e114 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -567,7 +567,7 @@ static __init int setup_disable_pku(char *arg)
 	return 1;
 }
 __setup("nopku", setup_disable_pku);
-#endif /* CONFIG_X86_64 */
+#endif
 
 #ifdef CONFIG_X86_KERNEL_IBT
 
@@ -1256,6 +1256,8 @@ static const __initconst struct x86_cpu_id cpu_vuln_whitelist[] = {
 #define MMIO_SBDS	BIT(2)
 /* CPU is affected by RETbleed, speculating where you would not expect it */
 #define RETBLEED	BIT(3)
+/* CPU is affected by SMT (cross-thread) return predictions */
+#define SMT_RSB		BIT(4)
 
 static const struct x86_cpu_id cpu_vuln_blacklist[] __initconst = {
 	VULNBL_INTEL_STEPPINGS(IVYBRIDGE,	X86_STEPPING_ANY,		SRBDS),
@@ -1287,8 +1289,8 @@ static const struct x86_cpu_id cpu_vuln_blacklist[] __initconst = {
 
 	VULNBL_AMD(0x15, RETBLEED),
 	VULNBL_AMD(0x16, RETBLEED),
-	VULNBL_AMD(0x17, RETBLEED),
-	VULNBL_HYGON(0x18, RETBLEED),
+	VULNBL_AMD(0x17, RETBLEED | SMT_RSB),
+	VULNBL_HYGON(0x18, RETBLEED | SMT_RSB),
 	{}
 };
 
@@ -1406,6 +1408,9 @@ static void __init cpu_set_bug_bits(struct cpuinfo_x86 *c)
 	    !(ia32_cap & ARCH_CAP_PBRSB_NO))
 		setup_force_cpu_bug(X86_BUG_EIBRS_PBRSB);
 
+	if (cpu_matches(cpu_vuln_blacklist, SMT_RSB))
+		setup_force_cpu_bug(X86_BUG_SMT_RSB);
+
 	if (cpu_matches(cpu_vuln_whitelist, NO_MELTDOWN))
 		return;
 
@@ -1953,7 +1958,6 @@ void __init identify_boot_cpu(void)
 	if (HAS_KERNEL_IBT && cpu_feature_enabled(X86_FEATURE_IBT))
 		pr_info("CET detected: Indirect Branch Tracking enabled\n");
 #ifdef CONFIG_X86_32
-	sysenter_setup();
 	enable_sep_cpu();
 #endif
 	cpu_detect_tlb(&boot_cpu_data);
@@ -2125,7 +2129,6 @@ static void wait_for_master_cpu(int cpu)
 #endif
 }
 
-#ifdef CONFIG_X86_64
 static inline void setup_getcpu(int cpu)
 {
 	unsigned long cpudata = vdso_encode_cpunode(cpu, early_cpu_to_node(cpu));
@@ -2147,6 +2150,7 @@ static inline void setup_getcpu(int cpu)
 	write_gdt_entry(get_cpu_gdt_rw(cpu), GDT_ENTRY_CPUNODE, &d, DESCTYPE_S);
 }
 
+#ifdef CONFIG_X86_64
 static inline void ucode_cpu_init(int cpu)
 {
 	if (cpu)
@@ -2166,8 +2170,6 @@ static inline void tss_setup_ist(struct tss_struct *tss)
 
 #else /* CONFIG_X86_64 */
 
-static inline void setup_getcpu(int cpu) { }
-
 static inline void ucode_cpu_init(int cpu)
 {
 	show_ucode_info_early();
@@ -2297,30 +2299,45 @@ void cpu_init_secondary(void)
 #endif
 
 #ifdef CONFIG_MICROCODE_LATE_LOADING
-/*
+/**
+ * store_cpu_caps() - Store a snapshot of CPU capabilities
+ * @curr_info: Pointer where to store it
+ *
+ * Returns: None
+ */
+void store_cpu_caps(struct cpuinfo_x86 *curr_info)
+{
+	/* Reload CPUID max function as it might've changed. */
+	curr_info->cpuid_level = cpuid_eax(0);
+
+	/* Copy all capability leafs and pick up the synthetic ones. */
+	memcpy(&curr_info->x86_capability, &boot_cpu_data.x86_capability,
+	       sizeof(curr_info->x86_capability));
+
+	/* Get the hardware CPUID leafs */
+	get_cpu_cap(curr_info);
+}
+
+/**
+ * microcode_check() - Check if any CPU capabilities changed after an update.
+ * @prev_info:	CPU capabilities stored before an update.
+ *
  * The microcode loader calls this upon late microcode load to recheck features,
  * only when microcode has been updated. Caller holds microcode_mutex and CPU
  * hotplug lock.
+ *
+ * Return: None
  */
-void microcode_check(void)
+void microcode_check(struct cpuinfo_x86 *prev_info)
 {
-	struct cpuinfo_x86 info;
+	struct cpuinfo_x86 curr_info;
 
 	perf_check_microcode();
 
-	/* Reload CPUID max function as it might've changed. */
-	info.cpuid_level = cpuid_eax(0);
-
-	/*
-	 * Copy all capability leafs to pick up the synthetic ones so that
-	 * memcmp() below doesn't fail on that. The ones coming from CPUID will
-	 * get overwritten in get_cpu_cap().
-	 */
-	memcpy(&info.x86_capability, &boot_cpu_data.x86_capability, sizeof(info.x86_capability));
-
-	get_cpu_cap(&info);
+	store_cpu_caps(&curr_info);
 
-	if (!memcmp(&info.x86_capability, &boot_cpu_data.x86_capability, sizeof(info.x86_capability)))
+	if (!memcmp(&prev_info->x86_capability, &curr_info.x86_capability,
+		    sizeof(prev_info->x86_capability)))
 		return;
 
 	pr_warn("x86/CPU: CPU features have changed after loading microcode, but might not take effect.\n");