diff --git a/arch/x86/Makefile b/arch/x86/Makefile
index 56e748a7679f4b931b420eaec6bd63f174337e59..94df0868804bcb4b9b37f7abf4985ac95158c4f8 100644
--- a/arch/x86/Makefile
+++ b/arch/x86/Makefile
@@ -38,6 +38,7 @@ REALMODE_CFLAGS	:= $(M16_CFLAGS) -g -Os -DDISABLE_BRANCH_PROFILING \
 
 REALMODE_CFLAGS += $(call __cc-option, $(CC), $(REALMODE_CFLAGS), -ffreestanding)
 REALMODE_CFLAGS += $(call __cc-option, $(CC), $(REALMODE_CFLAGS), -fno-stack-protector)
+REALMODE_CFLAGS += $(call __cc-option, $(CC), $(REALMODE_CFLAGS), -Wno-address-of-packed-member)
 REALMODE_CFLAGS += $(call __cc-option, $(CC), $(REALMODE_CFLAGS), $(cc_stack_align4))
 export REALMODE_CFLAGS
 
diff --git a/arch/x86/boot/compressed/pgtable_64.c b/arch/x86/boot/compressed/pgtable_64.c
index 2faddeb0398afff4bd24228bbaededb18893c976..c8862696a47b949be25235531a39a65db94eb8ba 100644
--- a/arch/x86/boot/compressed/pgtable_64.c
+++ b/arch/x86/boot/compressed/pgtable_64.c
@@ -72,7 +72,7 @@ static unsigned long find_trampoline_placement(void)
 
 	/* Find the first usable memory region under bios_start. */
 	for (i = boot_params->e820_entries - 1; i >= 0; i--) {
-		unsigned long new;
+		unsigned long new = bios_start;
 
 		entry = &boot_params->e820_table[i];
 
diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
index aa5495d0f47832fbc02d102a8fb66180a550b6e9..dba2828b779a57abe32892600be3fdc021a5254a 100644
--- a/arch/x86/kernel/apic/apic.c
+++ b/arch/x86/kernel/apic/apic.c
@@ -1179,6 +1179,10 @@ void clear_local_APIC(void)
 	apic_write(APIC_LVT0, v | APIC_LVT_MASKED);
 	v = apic_read(APIC_LVT1);
 	apic_write(APIC_LVT1, v | APIC_LVT_MASKED);
+	if (!x2apic_enabled()) {
+		v = apic_read(APIC_LDR) & ~APIC_LDR_MASK;
+		apic_write(APIC_LDR, v);
+	}
 	if (maxlvt >= 4) {
 		v = apic_read(APIC_LVTPC);
 		apic_write(APIC_LVTPC, v | APIC_LVT_MASKED);
diff --git a/arch/x86/kernel/apic/bigsmp_32.c b/arch/x86/kernel/apic/bigsmp_32.c
index afee386ff711e95132dd5c01e79317ac22bd9a56..caedd8d60d3610b8b9bc11f5669de16521b3ac2a 100644
--- a/arch/x86/kernel/apic/bigsmp_32.c
+++ b/arch/x86/kernel/apic/bigsmp_32.c
@@ -38,32 +38,12 @@ static int bigsmp_early_logical_apicid(int cpu)
 	return early_per_cpu(x86_cpu_to_apicid, cpu);
 }
 
-static inline unsigned long calculate_ldr(int cpu)
-{
-	unsigned long val, id;
-
-	val = apic_read(APIC_LDR) & ~APIC_LDR_MASK;
-	id = per_cpu(x86_bios_cpu_apicid, cpu);
-	val |= SET_APIC_LOGICAL_ID(id);
-
-	return val;
-}
-
 /*
- * Set up the logical destination ID.
- *
- * Intel recommends to set DFR, LDR and TPR before enabling
- * an APIC.  See e.g. "AP-388 82489DX User's Manual" (Intel
- * document number 292116).  So here it goes...
+ * bigsmp enables physical destination mode
+ * and doesn't use LDR and DFR
  */
 static void bigsmp_init_apic_ldr(void)
 {
-	unsigned long val;
-	int cpu = smp_processor_id();
-
-	apic_write(APIC_DFR, APIC_DFR_FLAT);
-	val = calculate_ldr(cpu);
-	apic_write(APIC_LDR, val);
 }
 
 static void bigsmp_setup_apic_routing(void)
diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
index c7bb6c69f21c98cbc24c9684820ee01122a5045b..d6af97fd170a98262a4618e613dd576f3e9f9f0b 100644
--- a/arch/x86/kernel/apic/io_apic.c
+++ b/arch/x86/kernel/apic/io_apic.c
@@ -2438,7 +2438,13 @@ unsigned int arch_dynirq_lower_bound(unsigned int from)
 	 * dmar_alloc_hwirq() may be called before setup_IO_APIC(), so use
 	 * gsi_top if ioapic_dynirq_base hasn't been initialized yet.
 	 */
-	return ioapic_initialized ? ioapic_dynirq_base : gsi_top;
+	if (!ioapic_initialized)
+		return gsi_top;
+	/*
+	 * For DT enabled machines ioapic_dynirq_base is irrelevant and not
+	 * updated. So simply return @from if ioapic_dynirq_base == 0.
+	 */
+	return ioapic_dynirq_base ? : from;
 }
 
 #ifdef CONFIG_X86_32
diff --git a/arch/x86/kernel/uprobes.c b/arch/x86/kernel/uprobes.c
index d8359ebeea70c26bb7f621a3f8fea1ffb3fbb421..8cd745ef8c7b78662b561cb46e2d6c2beb388876 100644
--- a/arch/x86/kernel/uprobes.c
+++ b/arch/x86/kernel/uprobes.c
@@ -508,9 +508,12 @@ struct uprobe_xol_ops {
 	void	(*abort)(struct arch_uprobe *, struct pt_regs *);
 };
 
-static inline int sizeof_long(void)
+static inline int sizeof_long(struct pt_regs *regs)
 {
-	return in_ia32_syscall() ? 4 : 8;
+	/*
+	 * Check registers for mode as in_xxx_syscall() does not apply here.
+	 */
+	return user_64bit_mode(regs) ? 8 : 4;
 }
 
 static int default_pre_xol_op(struct arch_uprobe *auprobe, struct pt_regs *regs)
@@ -521,9 +524,9 @@ static int default_pre_xol_op(struct arch_uprobe *auprobe, struct pt_regs *regs)
 
 static int emulate_push_stack(struct pt_regs *regs, unsigned long val)
 {
-	unsigned long new_sp = regs->sp - sizeof_long();
+	unsigned long new_sp = regs->sp - sizeof_long(regs);
 
-	if (copy_to_user((void __user *)new_sp, &val, sizeof_long()))
+	if (copy_to_user((void __user *)new_sp, &val, sizeof_long(regs)))
 		return -EFAULT;
 
 	regs->sp = new_sp;
@@ -556,7 +559,7 @@ static int default_post_xol_op(struct arch_uprobe *auprobe, struct pt_regs *regs
 		long correction = utask->vaddr - utask->xol_vaddr;
 		regs->ip += correction;
 	} else if (auprobe->defparam.fixups & UPROBE_FIX_CALL) {
-		regs->sp += sizeof_long(); /* Pop incorrect return address */
+		regs->sp += sizeof_long(regs); /* Pop incorrect return address */
 		if (emulate_push_stack(regs, utask->vaddr + auprobe->defparam.ilen))
 			return -ERESTART;
 	}
@@ -675,7 +678,7 @@ static int branch_post_xol_op(struct arch_uprobe *auprobe, struct pt_regs *regs)
 	 * "call" insn was executed out-of-line. Just restore ->sp and restart.
 	 * We could also restore ->ip and try to call branch_emulate_op() again.
 	 */
-	regs->sp += sizeof_long();
+	regs->sp += sizeof_long(regs);
 	return -ERESTART;
 }
 
@@ -1056,7 +1059,7 @@ bool arch_uprobe_skip_sstep(struct arch_uprobe *auprobe, struct pt_regs *regs)
 unsigned long
 arch_uretprobe_hijack_return_addr(unsigned long trampoline_vaddr, struct pt_regs *regs)
 {
-	int rasize = sizeof_long(), nleft;
+	int rasize = sizeof_long(regs), nleft;
 	unsigned long orig_ret_vaddr = 0; /* clear high bits for 32-bit apps */
 
 	if (copy_from_user(&orig_ret_vaddr, (void __user *)regs->sp, rasize))
diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c
index 6a9a77a403c928e642a754f68c168ebfa6f7b3c1..e14e95ea7338a3adaf013acb7cd848d909f4dd95 100644
--- a/arch/x86/mm/pageattr.c
+++ b/arch/x86/mm/pageattr.c
@@ -516,7 +516,7 @@ static inline void check_conflict(int warnlvl, pgprot_t prot, pgprotval_t val,
  */
 static inline pgprot_t static_protections(pgprot_t prot, unsigned long start,
 					  unsigned long pfn, unsigned long npg,
-					  int warnlvl)
+					  unsigned long lpsize, int warnlvl)
 {
 	pgprotval_t forbidden, res;
 	unsigned long end;
@@ -535,9 +535,17 @@ static inline pgprot_t static_protections(pgprot_t prot, unsigned long start,
 	check_conflict(warnlvl, prot, res, start, end, pfn, "Text NX");
 	forbidden = res;
 
-	res = protect_kernel_text_ro(start, end);
-	check_conflict(warnlvl, prot, res, start, end, pfn, "Text RO");
-	forbidden |= res;
+	/*
+	 * Special case to preserve a large page. If the change spawns the
+	 * full large page mapping then there is no point to split it
+	 * up. Happens with ftrace and is going to be removed once ftrace
+	 * switched to text_poke().
+	 */
+	if (lpsize != (npg * PAGE_SIZE) || (start & (lpsize - 1))) {
+		res = protect_kernel_text_ro(start, end);
+		check_conflict(warnlvl, prot, res, start, end, pfn, "Text RO");
+		forbidden |= res;
+	}
 
 	/* Check the PFN directly */
 	res = protect_pci_bios(pfn, pfn + npg - 1);
@@ -819,7 +827,7 @@ static int __should_split_large_page(pte_t *kpte, unsigned long address,
 	 * extra conditional required here.
 	 */
 	chk_prot = static_protections(old_prot, lpaddr, old_pfn, numpages,
-				      CPA_CONFLICT);
+				      psize, CPA_CONFLICT);
 
 	if (WARN_ON_ONCE(pgprot_val(chk_prot) != pgprot_val(old_prot))) {
 		/*
@@ -855,7 +863,7 @@ static int __should_split_large_page(pte_t *kpte, unsigned long address,
 	 * protection requirement in the large page.
 	 */
 	new_prot = static_protections(req_prot, lpaddr, old_pfn, numpages,
-				      CPA_DETECT);
+				      psize, CPA_DETECT);
 
 	/*
 	 * If there is a conflict, split the large page.
@@ -906,7 +914,8 @@ static void split_set_pte(struct cpa_data *cpa, pte_t *pte, unsigned long pfn,
 	if (!cpa->force_static_prot)
 		goto set;
 
-	prot = static_protections(ref_prot, address, pfn, npg, CPA_PROTECT);
+	/* Hand in lpsize = 0 to enforce the protection mechanism */
+	prot = static_protections(ref_prot, address, pfn, npg, 0, CPA_PROTECT);
 
 	if (pgprot_val(prot) == pgprot_val(ref_prot))
 		goto set;
@@ -1503,7 +1512,8 @@ static int __change_page_attr(struct cpa_data *cpa, int primary)
 		pgprot_val(new_prot) |= pgprot_val(cpa->mask_set);
 
 		cpa_inc_4k_install();
-		new_prot = static_protections(new_prot, address, pfn, 1,
+		/* Hand in lpsize = 0 to enforce the protection mechanism */
+		new_prot = static_protections(new_prot, address, pfn, 1, 0,
 					      CPA_PROTECT);
 
 		new_prot = pgprot_clear_protnone_bits(new_prot);