Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c
index d3e593e..b8ceec4 100644
--- a/arch/x86/kernel/process_32.c
+++ b/arch/x86/kernel/process_32.c
@@ -44,9 +44,6 @@
 #include <asm/processor.h>
 #include <asm/fpu/internal.h>
 #include <asm/desc.h>
-#ifdef CONFIG_MATH_EMULATION
-#include <asm/math_emu.h>
-#endif
 
 #include <linux/err.h>
 
@@ -56,7 +53,7 @@
 #include <asm/debugreg.h>
 #include <asm/switch_to.h>
 #include <asm/vm86.h>
-#include <asm/intel_rdt_sched.h>
+#include <asm/resctrl_sched.h>
 #include <asm/proto.h>
 
 #include "process.h"
@@ -65,27 +62,21 @@
 {
 	unsigned long cr0 = 0L, cr2 = 0L, cr3 = 0L, cr4 = 0L;
 	unsigned long d0, d1, d2, d3, d6, d7;
-	unsigned long sp;
-	unsigned short ss, gs;
+	unsigned short gs;
 
-	if (user_mode(regs)) {
-		sp = regs->sp;
-		ss = regs->ss;
+	if (user_mode(regs))
 		gs = get_user_gs(regs);
-	} else {
-		sp = kernel_stack_pointer(regs);
-		savesegment(ss, ss);
+	else
 		savesegment(gs, gs);
-	}
 
 	show_ip(regs, KERN_DEFAULT);
 
 	printk(KERN_DEFAULT "EAX: %08lx EBX: %08lx ECX: %08lx EDX: %08lx\n",
 		regs->ax, regs->bx, regs->cx, regs->dx);
 	printk(KERN_DEFAULT "ESI: %08lx EDI: %08lx EBP: %08lx ESP: %08lx\n",
-		regs->si, regs->di, regs->bp, sp);
+		regs->si, regs->di, regs->bp, regs->sp);
 	printk(KERN_DEFAULT "DS: %04x ES: %04x FS: %04x GS: %04x SS: %04x EFLAGS: %08lx\n",
-	       (u16)regs->ds, (u16)regs->es, (u16)regs->fs, gs, ss, regs->flags);
+	       (u16)regs->ds, (u16)regs->es, (u16)regs->fs, gs, regs->ss, regs->flags);
 
 	if (mode != SHOW_REGS_ALL)
 		return;
@@ -130,6 +121,13 @@
 	struct task_struct *tsk;
 	int err;
 
+	/*
+	 * For a new task use the RESET flags value since there is no before.
+	 * All the status flags are zero; DF and all the system flags must also
+	 * be 0, specifically IF must be 0 because we context switch to the new
+	 * task with interrupts disabled.
+	 */
+	frame->flags = X86_EFLAGS_FIXED;
 	frame->bp = 0;
 	frame->ret_addr = (unsigned long) ret_from_fork;
 	p->thread.sp = (unsigned long) fork_frame;
@@ -237,7 +235,8 @@
 
 	/* never put a printk in __switch_to... printk() calls wake_up*() indirectly */
 
-	switch_fpu_prepare(prev_fpu, cpu);
+	if (!test_thread_flag(TIF_NEED_FPU_LOAD))
+		switch_fpu_prepare(prev_fpu, cpu);
 
 	/*
 	 * Save away %gs. No need to save %fs, as it was saved on the
@@ -270,9 +269,7 @@
 	/*
 	 * Leave lazy mode, flushing any hypercalls made here.
 	 * This must be done before restoring TLS segments so
-	 * the GDT and LDT are properly updated, and must be
-	 * done before fpu__restore(), so the TS bit is up
-	 * to date.
+	 * the GDT and LDT are properly updated.
 	 */
 	arch_end_context_switch(next_p);
 
@@ -293,12 +290,12 @@
 	if (prev->gs | next->gs)
 		lazy_load_gs(next->gs);
 
-	switch_fpu_finish(next_fpu, cpu);
-
 	this_cpu_write(current_task, next_p);
 
+	switch_fpu_finish(next_fpu);
+
 	/* Load the Intel cache allocation PQR MSR. */
-	intel_rdt_sched_in();
+	resctrl_sched_in();
 
 	return prev_p;
 }