Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/arch/x86/kernel/idt.c b/arch/x86/kernel/idt.c
index 01adea2..87ef69a 100644
--- a/arch/x86/kernel/idt.c
+++ b/arch/x86/kernel/idt.c
@@ -1,7 +1,6 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * Interrupt descriptor table related code
- *
- * This file is licensed under the GPL V2
  */
 #include <linux/interrupt.h>
 
@@ -41,13 +40,12 @@
 #define SYSG(_vector, _addr)				\
 	G(_vector, _addr, DEFAULT_STACK, GATE_INTERRUPT, DPL3, __KERNEL_CS)
 
-/* Interrupt gate with interrupt stack */
+/*
+ * Interrupt gate with interrupt stack. The _ist index is the index in
+ * the tss.ist[] array, but for the descriptor it needs to start at 1.
+ */
 #define ISTG(_vector, _addr, _ist)			\
-	G(_vector, _addr, _ist, GATE_INTERRUPT, DPL0, __KERNEL_CS)
-
-/* System interrupt gate with interrupt stack */
-#define SISTG(_vector, _addr, _ist)			\
-	G(_vector, _addr, _ist, GATE_INTERRUPT, DPL3, __KERNEL_CS)
+	G(_vector, _addr, _ist + 1, GATE_INTERRUPT, DPL0, __KERNEL_CS)
 
 /* Task gate */
 #define TSKG(_vector, _gdt)				\
@@ -184,11 +182,11 @@
  * cpu_init() when the TSS has been initialized.
  */
 static const __initconst struct idt_data ist_idts[] = {
-	ISTG(X86_TRAP_DB,	debug,		DEBUG_STACK),
-	ISTG(X86_TRAP_NMI,	nmi,		NMI_STACK),
-	ISTG(X86_TRAP_DF,	double_fault,	DOUBLEFAULT_STACK),
+	ISTG(X86_TRAP_DB,	debug,		IST_INDEX_DB),
+	ISTG(X86_TRAP_NMI,	nmi,		IST_INDEX_NMI),
+	ISTG(X86_TRAP_DF,	double_fault,	IST_INDEX_DF),
 #ifdef CONFIG_X86_MCE
-	ISTG(X86_TRAP_MC,	&machine_check,	MCE_STACK),
+	ISTG(X86_TRAP_MC,	&machine_check,	IST_INDEX_MCE),
 #endif
 };
 
@@ -321,7 +319,8 @@
 #ifdef CONFIG_X86_LOCAL_APIC
 	for_each_clear_bit_from(i, system_vectors, NR_VECTORS) {
 		set_bit(i, system_vectors);
-		set_intr_gate(i, spurious_interrupt);
+		entry = spurious_entries_start + 8 * (i - FIRST_SYSTEM_VECTOR);
+		set_intr_gate(i, entry);
 	}
 #endif
 }