Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/arch/um/include/asm/Kbuild b/arch/um/include/asm/Kbuild
index b10dde6..398006d 100644
--- a/arch/um/include/asm/Kbuild
+++ b/arch/um/include/asm/Kbuild
@@ -1,4 +1,4 @@
-generic-y += barrier.h
+# SPDX-License-Identifier: GPL-2.0
 generic-y += bpf_perf_event.h
 generic-y += bug.h
 generic-y += compat.h
@@ -10,14 +10,13 @@
 generic-y += extable.h
 generic-y += ftrace.h
 generic-y += futex.h
-generic-y += hardirq.h
 generic-y += hw_irq.h
-generic-y += io.h
 generic-y += irq_regs.h
 generic-y += irq_work.h
 generic-y += kdebug.h
 generic-y += mcs_spinlock.h
 generic-y += mm-arch-hooks.h
+generic-y += mmiowb.h
 generic-y += param.h
 generic-y += pci.h
 generic-y += percpu.h
diff --git a/arch/um/include/asm/a.out-core.h b/arch/um/include/asm/a.out-core.h
deleted file mode 100644
index 995643b..0000000
--- a/arch/um/include/asm/a.out-core.h
+++ /dev/null
@@ -1,27 +0,0 @@
-/* a.out coredump register dumper
- *
- * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
- * Written by David Howells (dhowells@redhat.com)
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public Licence
- * as published by the Free Software Foundation; either version
- * 2 of the Licence, or (at your option) any later version.
- */
-
-#ifndef __UM_A_OUT_CORE_H
-#define __UM_A_OUT_CORE_H
-
-#ifdef __KERNEL__
-
-#include <linux/user.h>
-
-/*
- * fill in the user structure for an a.out core dump
- */
-static inline void aout_dump_thread(struct pt_regs *regs, struct user *u)
-{
-}
-
-#endif /* __KERNEL__ */
-#endif /* __UM_A_OUT_CORE_H */
diff --git a/arch/um/include/asm/common.lds.S b/arch/um/include/asm/common.lds.S
index 7adb4e6..d7086b9 100644
--- a/arch/um/include/asm/common.lds.S
+++ b/arch/um/include/asm/common.lds.S
@@ -53,8 +53,6 @@
 	CON_INITCALL
   }
 
-  SECURITY_INIT
-
   .exitcall : {
 	__exitcall_begin = .;
 	*(.exitcall.exit)
@@ -85,8 +83,8 @@
 	__preinit_array_end = .;
   }
   .init_array : {
+        /* dummy - we call this ourselves */
 	__init_array_start = .;
-	*(.init_array)
 	__init_array_end = .;
   }
   .fini_array : {
diff --git a/arch/um/include/asm/irq.h b/arch/um/include/asm/irq.h
index 49ed3e3..42c6205 100644
--- a/arch/um/include/asm/irq.h
+++ b/arch/um/include/asm/irq.h
@@ -17,17 +17,18 @@
 #define TELNETD_IRQ 		12
 #define XTERM_IRQ 		13
 #define RANDOM_IRQ 		14
+#define VIRTIO_IRQ		15
 
 #ifdef CONFIG_UML_NET_VECTOR
 
-#define VECTOR_BASE_IRQ		15
+#define VECTOR_BASE_IRQ		(VIRTIO_IRQ + 1)
 #define VECTOR_IRQ_SPACE	8
 
-#define LAST_IRQ (VECTOR_IRQ_SPACE + VECTOR_BASE_IRQ)
+#define LAST_IRQ (VECTOR_IRQ_SPACE + VECTOR_BASE_IRQ - 1)
 
 #else
 
-#define LAST_IRQ RANDOM_IRQ
+#define LAST_IRQ VIRTIO_IRQ
 
 #endif
 
diff --git a/arch/um/include/asm/irqflags.h b/arch/um/include/asm/irqflags.h
index cbc6c00..0642ad9 100644
--- a/arch/um/include/asm/irqflags.h
+++ b/arch/um/include/asm/irqflags.h
@@ -32,7 +32,6 @@
 }
 
 #define ARCH_IRQ_DISABLED	0
-#define ARCh_IRQ_ENABLED	(SIGIO|SIGVTALRM)
 
 #include <asm-generic/irqflags.h>
 
diff --git a/arch/um/include/asm/kmap_types.h b/arch/um/include/asm/kmap_types.h
index 2e0a6b1..b0bd12d 100644
--- a/arch/um/include/asm/kmap_types.h
+++ b/arch/um/include/asm/kmap_types.h
@@ -1,6 +1,6 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /* 
  * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
- * Licensed under the GPL
  */
 
 #ifndef __UM_KMAP_TYPES_H
diff --git a/arch/um/include/asm/mmu.h b/arch/um/include/asm/mmu.h
index da70544..5b072ab 100644
--- a/arch/um/include/asm/mmu.h
+++ b/arch/um/include/asm/mmu.h
@@ -1,6 +1,6 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /* 
  * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
- * Licensed under the GPL
  */
 
 #ifndef __ARCH_UM_MMU_H
diff --git a/arch/um/include/asm/mmu_context.h b/arch/um/include/asm/mmu_context.h
index fca34b2..5aee062 100644
--- a/arch/um/include/asm/mmu_context.h
+++ b/arch/um/include/asm/mmu_context.h
@@ -1,6 +1,6 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /* 
  * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
- * Licensed under the GPL
  */
 
 #ifndef __UM_MMU_CONTEXT_H
@@ -22,7 +22,6 @@
 }
 extern void arch_exit_mmap(struct mm_struct *mm);
 static inline void arch_unmap(struct mm_struct *mm,
-			struct vm_area_struct *vma,
 			unsigned long start, unsigned long end)
 {
 }
@@ -53,7 +52,7 @@
 	 * when the new ->mm is used for the first time.
 	 */
 	__switch_mm(&new->context.id);
-	down_write(&new->mmap_sem);
+	down_write_nested(&new->mmap_sem, 1);
 	uml_setup_stubs(new);
 	up_write(&new->mmap_sem);
 }
diff --git a/arch/um/include/asm/page.h b/arch/um/include/asm/page.h
index f878bec..95af12e 100644
--- a/arch/um/include/asm/page.h
+++ b/arch/um/include/asm/page.h
@@ -1,7 +1,7 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * Copyright (C) 2000 - 2003 Jeff Dike (jdike@addtoit.com)
  * Copyright 2003 PathScale, Inc.
- * Licensed under the GPL
  */
 
 #ifndef __UM_PAGE_H
diff --git a/arch/um/include/asm/pgalloc.h b/arch/um/include/asm/pgalloc.h
index bf90b2a..881e76d 100644
--- a/arch/um/include/asm/pgalloc.h
+++ b/arch/um/include/asm/pgalloc.h
@@ -1,8 +1,8 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /* 
  * Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com)
  * Copyright 2003 PathScale, Inc.
  * Derived from include/asm-i386/pgalloc.h and include/asm-i386/pgtable.h
- * Licensed under the GPL
  */
 
 #ifndef __UM_PGALLOC_H
@@ -10,6 +10,8 @@
 
 #include <linux/mm.h>
 
+#include <asm-generic/pgalloc.h>	/* for pte_{alloc,free}_one */
+
 #define pmd_populate_kernel(mm, pmd, pte) \
 	set_pmd(pmd, __pmd(_PAGE_TABLE + (unsigned long) __pa(pte)))
 
@@ -25,23 +27,9 @@
 extern pgd_t *pgd_alloc(struct mm_struct *);
 extern void pgd_free(struct mm_struct *mm, pgd_t *pgd);
 
-extern pte_t *pte_alloc_one_kernel(struct mm_struct *, unsigned long);
-extern pgtable_t pte_alloc_one(struct mm_struct *, unsigned long);
-
-static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
-{
-	free_page((unsigned long) pte);
-}
-
-static inline void pte_free(struct mm_struct *mm, pgtable_t pte)
-{
-	pgtable_page_dtor(pte);
-	__free_page(pte);
-}
-
 #define __pte_free_tlb(tlb,pte, address)		\
 do {							\
-	pgtable_page_dtor(pte);				\
+	pgtable_pte_page_dtor(pte);			\
 	tlb_remove_page((tlb),(pte));			\
 } while (0)
 
@@ -55,7 +43,5 @@
 #define __pmd_free_tlb(tlb,x, address)   tlb_remove_page((tlb),virt_to_page(x))
 #endif
 
-#define check_pgt_cache()	do { } while (0)
-
 #endif
 
diff --git a/arch/um/include/asm/pgtable-2level.h b/arch/um/include/asm/pgtable-2level.h
index 179c0ea..32b3d26 100644
--- a/arch/um/include/asm/pgtable-2level.h
+++ b/arch/um/include/asm/pgtable-2level.h
@@ -1,8 +1,8 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com)
  * Copyright 2003 PathScale, Inc.
  * Derived from include/asm-i386/pgtable.h
- * Licensed under the GPL
  */
 
 #ifndef __UM_PGTABLE_2LEVEL_H
diff --git a/arch/um/include/asm/pgtable-3level.h b/arch/um/include/asm/pgtable-3level.h
index c4d876d..9812269 100644
--- a/arch/um/include/asm/pgtable-3level.h
+++ b/arch/um/include/asm/pgtable-3level.h
@@ -1,7 +1,7 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * Copyright 2003 PathScale Inc
  * Derived from include/asm-i386/pgtable.h
- * Licensed under the GPL
  */
 
 #ifndef __UM_PGTABLE_3LEVEL_H
diff --git a/arch/um/include/asm/pgtable.h b/arch/um/include/asm/pgtable.h
index 7485398..36a44d5 100644
--- a/arch/um/include/asm/pgtable.h
+++ b/arch/um/include/asm/pgtable.h
@@ -1,8 +1,8 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /* 
  * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
  * Copyright 2003 PathScale, Inc.
  * Derived from include/asm-i386/pgtable.h
- * Licensed under the GPL
  */
 
 #ifndef __UM_PGTABLE_H
@@ -32,8 +32,6 @@
 /* zero page used for uninitialized stuff */
 extern unsigned long *empty_zero_page;
 
-#define pgtable_cache_init() do ; while (0)
-
 /* Just any arbitrary offset to the start of the vmalloc VM area: the
  * current 8MB value just means that there will be a 8MB "hole" after the
  * physical memory until the kernel virtual memory starts.  That means that
@@ -197,12 +195,17 @@
 
 static inline pte_t pte_wrprotect(pte_t pte)
 { 
-	pte_clear_bits(pte, _PAGE_RW);
+	if (likely(pte_get_bits(pte, _PAGE_RW)))
+		pte_clear_bits(pte, _PAGE_RW);
+	else
+		return pte;
 	return(pte_mknewprot(pte)); 
 }
 
 static inline pte_t pte_mkread(pte_t pte)
 { 
+	if (unlikely(pte_get_bits(pte, _PAGE_USER)))
+		return pte;
 	pte_set_bits(pte, _PAGE_USER);
 	return(pte_mknewprot(pte)); 
 }
@@ -221,6 +224,8 @@
 
 static inline pte_t pte_mkwrite(pte_t pte)	
 {
+	if (unlikely(pte_get_bits(pte,  _PAGE_RW)))
+		return pte;
 	pte_set_bits(pte, _PAGE_RW);
 	return(pte_mknewprot(pte)); 
 }
@@ -256,7 +261,12 @@
 	*pteptr = pte_mknewpage(*pteptr);
 	if(pte_present(*pteptr)) *pteptr = pte_mknewprot(*pteptr);
 }
-#define set_pte_at(mm,addr,ptep,pteval) set_pte(ptep,pteval)
+
+static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
+			      pte_t *pteptr, pte_t pteval)
+{
+	set_pte(pteptr, pteval);
+}
 
 #define __HAVE_ARCH_PTE_SAME
 static inline int pte_same(pte_t pte_a, pte_t pte_b)
diff --git a/arch/um/include/asm/processor-generic.h b/arch/um/include/asm/processor-generic.h
index b58b746..afd9b26 100644
--- a/arch/um/include/asm/processor-generic.h
+++ b/arch/um/include/asm/processor-generic.h
@@ -1,6 +1,6 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /* 
  * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
- * Licensed under the GPL
  */
 
 #ifndef __UM_PROCESSOR_GENERIC_H
diff --git a/arch/um/include/asm/ptrace-generic.h b/arch/um/include/asm/ptrace-generic.h
index 5ab2062..81c647e 100644
--- a/arch/um/include/asm/ptrace-generic.h
+++ b/arch/um/include/asm/ptrace-generic.h
@@ -1,6 +1,6 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /* 
  * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
- * Licensed under the GPL
  */
 
 #ifndef __UM_PTRACE_GENERIC_H
diff --git a/arch/um/include/asm/syscall-generic.h b/arch/um/include/asm/syscall-generic.h
index 9fb9cf8..2984feb 100644
--- a/arch/um/include/asm/syscall-generic.h
+++ b/arch/um/include/asm/syscall-generic.h
@@ -1,13 +1,10 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
 /*
  * Access to user system call parameters and results
  *
  * See asm-generic/syscall.h for function descriptions.
  *
  * Copyright (C) 2015 Mickaël Salaün <mic@digikod.net>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
  */
 
 #ifndef __UM_SYSCALL_GENERIC_H
@@ -53,84 +50,30 @@
 
 static inline void syscall_get_arguments(struct task_struct *task,
 					 struct pt_regs *regs,
-					 unsigned int i, unsigned int n,
 					 unsigned long *args)
 {
 	const struct uml_pt_regs *r = &regs->regs;
 
-	switch (i) {
-	case 0:
-		if (!n--)
-			break;
-		*args++ = UPT_SYSCALL_ARG1(r);
-	case 1:
-		if (!n--)
-			break;
-		*args++ = UPT_SYSCALL_ARG2(r);
-	case 2:
-		if (!n--)
-			break;
-		*args++ = UPT_SYSCALL_ARG3(r);
-	case 3:
-		if (!n--)
-			break;
-		*args++ = UPT_SYSCALL_ARG4(r);
-	case 4:
-		if (!n--)
-			break;
-		*args++ = UPT_SYSCALL_ARG5(r);
-	case 5:
-		if (!n--)
-			break;
-		*args++ = UPT_SYSCALL_ARG6(r);
-	case 6:
-		if (!n--)
-			break;
-	default:
-		BUG();
-		break;
-	}
+	*args++ = UPT_SYSCALL_ARG1(r);
+	*args++ = UPT_SYSCALL_ARG2(r);
+	*args++ = UPT_SYSCALL_ARG3(r);
+	*args++ = UPT_SYSCALL_ARG4(r);
+	*args++ = UPT_SYSCALL_ARG5(r);
+	*args   = UPT_SYSCALL_ARG6(r);
 }
 
 static inline void syscall_set_arguments(struct task_struct *task,
 					 struct pt_regs *regs,
-					 unsigned int i, unsigned int n,
 					 const unsigned long *args)
 {
 	struct uml_pt_regs *r = &regs->regs;
 
-	switch (i) {
-	case 0:
-		if (!n--)
-			break;
-		UPT_SYSCALL_ARG1(r) = *args++;
-	case 1:
-		if (!n--)
-			break;
-		UPT_SYSCALL_ARG2(r) = *args++;
-	case 2:
-		if (!n--)
-			break;
-		UPT_SYSCALL_ARG3(r) = *args++;
-	case 3:
-		if (!n--)
-			break;
-		UPT_SYSCALL_ARG4(r) = *args++;
-	case 4:
-		if (!n--)
-			break;
-		UPT_SYSCALL_ARG5(r) = *args++;
-	case 5:
-		if (!n--)
-			break;
-		UPT_SYSCALL_ARG6(r) = *args++;
-	case 6:
-		if (!n--)
-			break;
-	default:
-		BUG();
-		break;
-	}
+	UPT_SYSCALL_ARG1(r) = *args++;
+	UPT_SYSCALL_ARG2(r) = *args++;
+	UPT_SYSCALL_ARG3(r) = *args++;
+	UPT_SYSCALL_ARG4(r) = *args++;
+	UPT_SYSCALL_ARG5(r) = *args++;
+	UPT_SYSCALL_ARG6(r) = *args;
 }
 
 /* See arch/x86/um/asm/syscall.h for syscall_get_arch() definition. */
diff --git a/arch/um/include/asm/thread_info.h b/arch/um/include/asm/thread_info.h
index 4eecd96..4c19ce4 100644
--- a/arch/um/include/asm/thread_info.h
+++ b/arch/um/include/asm/thread_info.h
@@ -1,6 +1,6 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
- * Licensed under the GPL
  */
 
 #ifndef __UM_THREAD_INFO_H
diff --git a/arch/um/include/asm/tlb.h b/arch/um/include/asm/tlb.h
index dce6db1..70ee603 100644
--- a/arch/um/include/asm/tlb.h
+++ b/arch/um/include/asm/tlb.h
@@ -2,162 +2,8 @@
 #ifndef __UM_TLB_H
 #define __UM_TLB_H
 
-#include <linux/pagemap.h>
-#include <linux/swap.h>
-#include <asm/percpu.h>
-#include <asm/pgalloc.h>
 #include <asm/tlbflush.h>
-
-#define tlb_start_vma(tlb, vma) do { } while (0)
-#define tlb_end_vma(tlb, vma) do { } while (0)
-#define tlb_flush(tlb) flush_tlb_mm((tlb)->mm)
-
-/* struct mmu_gather is an opaque type used by the mm code for passing around
- * any data needed by arch specific code for tlb_remove_page.
- */
-struct mmu_gather {
-	struct mm_struct	*mm;
-	unsigned int		need_flush; /* Really unmapped some ptes? */
-	unsigned long		start;
-	unsigned long		end;
-	unsigned int		fullmm; /* non-zero means full mm flush */
-};
-
-static inline void __tlb_remove_tlb_entry(struct mmu_gather *tlb, pte_t *ptep,
-					  unsigned long address)
-{
-	if (tlb->start > address)
-		tlb->start = address;
-	if (tlb->end < address + PAGE_SIZE)
-		tlb->end = address + PAGE_SIZE;
-}
-
-static inline void init_tlb_gather(struct mmu_gather *tlb)
-{
-	tlb->need_flush = 0;
-
-	tlb->start = TASK_SIZE;
-	tlb->end = 0;
-
-	if (tlb->fullmm) {
-		tlb->start = 0;
-		tlb->end = TASK_SIZE;
-	}
-}
-
-static inline void
-arch_tlb_gather_mmu(struct mmu_gather *tlb, struct mm_struct *mm,
-		unsigned long start, unsigned long end)
-{
-	tlb->mm = mm;
-	tlb->start = start;
-	tlb->end = end;
-	tlb->fullmm = !(start | (end+1));
-
-	init_tlb_gather(tlb);
-}
-
-extern void flush_tlb_mm_range(struct mm_struct *mm, unsigned long start,
-			       unsigned long end);
-
-static inline void
-tlb_flush_mmu_tlbonly(struct mmu_gather *tlb)
-{
-	flush_tlb_mm_range(tlb->mm, tlb->start, tlb->end);
-}
-
-static inline void
-tlb_flush_mmu_free(struct mmu_gather *tlb)
-{
-	init_tlb_gather(tlb);
-}
-
-static inline void
-tlb_flush_mmu(struct mmu_gather *tlb)
-{
-	if (!tlb->need_flush)
-		return;
-
-	tlb_flush_mmu_tlbonly(tlb);
-	tlb_flush_mmu_free(tlb);
-}
-
-/* arch_tlb_finish_mmu
- *	Called at the end of the shootdown operation to free up any resources
- *	that were required.
- */
-static inline void
-arch_tlb_finish_mmu(struct mmu_gather *tlb,
-		unsigned long start, unsigned long end, bool force)
-{
-	if (force) {
-		tlb->start = start;
-		tlb->end = end;
-		tlb->need_flush = 1;
-	}
-	tlb_flush_mmu(tlb);
-
-	/* keep the page table cache within bounds */
-	check_pgt_cache();
-}
-
-/* tlb_remove_page
- *	Must perform the equivalent to __free_pte(pte_get_and_clear(ptep)),
- *	while handling the additional races in SMP caused by other CPUs
- *	caching valid mappings in their TLBs.
- */
-static inline int __tlb_remove_page(struct mmu_gather *tlb, struct page *page)
-{
-	tlb->need_flush = 1;
-	free_page_and_swap_cache(page);
-	return false; /* avoid calling tlb_flush_mmu */
-}
-
-static inline void tlb_remove_page(struct mmu_gather *tlb, struct page *page)
-{
-	__tlb_remove_page(tlb, page);
-}
-
-static inline bool __tlb_remove_page_size(struct mmu_gather *tlb,
-					  struct page *page, int page_size)
-{
-	return __tlb_remove_page(tlb, page);
-}
-
-static inline void tlb_remove_page_size(struct mmu_gather *tlb,
-					struct page *page, int page_size)
-{
-	return tlb_remove_page(tlb, page);
-}
-
-/**
- * tlb_remove_tlb_entry - remember a pte unmapping for later tlb invalidation.
- *
- * Record the fact that pte's were really umapped in ->need_flush, so we can
- * later optimise away the tlb invalidate.   This helps when userspace is
- * unmapping already-unmapped pages, which happens quite a lot.
- */
-#define tlb_remove_tlb_entry(tlb, ptep, address)		\
-	do {							\
-		tlb->need_flush = 1;				\
-		__tlb_remove_tlb_entry(tlb, ptep, address);	\
-	} while (0)
-
-#define tlb_remove_huge_tlb_entry(h, tlb, ptep, address)	\
-	tlb_remove_tlb_entry(tlb, ptep, address)
-
-#define tlb_remove_check_page_size_change tlb_remove_check_page_size_change
-static inline void tlb_remove_check_page_size_change(struct mmu_gather *tlb,
-						     unsigned int page_size)
-{
-}
-
-#define pte_free_tlb(tlb, ptep, addr) __pte_free_tlb(tlb, ptep, addr)
-
-#define pud_free_tlb(tlb, pudp, addr) __pud_free_tlb(tlb, pudp, addr)
-
-#define pmd_free_tlb(tlb, pmdp, addr) __pmd_free_tlb(tlb, pmdp, addr)
-
-#define tlb_migrate_finish(mm) do {} while (0)
+#include <asm-generic/cacheflush.h>
+#include <asm-generic/tlb.h>
 
 #endif
diff --git a/arch/um/include/asm/tlbflush.h b/arch/um/include/asm/tlbflush.h
index 614f2c0..a5bda89 100644
--- a/arch/um/include/asm/tlbflush.h
+++ b/arch/um/include/asm/tlbflush.h
@@ -1,6 +1,6 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
- * Licensed under the GPL
  */
 
 #ifndef __UM_TLBFLUSH_H
diff --git a/arch/um/include/asm/uaccess.h b/arch/um/include/asm/uaccess.h
index cc00fc5..fe66d65 100644
--- a/arch/um/include/asm/uaccess.h
+++ b/arch/um/include/asm/uaccess.h
@@ -1,7 +1,7 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /* 
  * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
  * Copyright (C) 2015 Richard Weinberger (richard@nod.at)
- * Licensed under the GPL
  */
 
 #ifndef __UM_UACCESS_H
diff --git a/arch/um/include/shared/aio.h b/arch/um/include/shared/aio.h
deleted file mode 100644
index 423bae9..0000000
--- a/arch/um/include/shared/aio.h
+++ /dev/null
@@ -1,28 +0,0 @@
-/*
- * Copyright (C) 2004 Jeff Dike (jdike@karaya.com)
- * Licensed under the GPL
- */
-
-#ifndef AIO_H__
-#define AIO_H__
-
-enum aio_type { AIO_READ, AIO_WRITE, AIO_MMAP };
-
-struct aio_thread_reply {
-	void *data;
-	int err;
-};
-
-struct aio_context {
-	int reply_fd;
-	struct aio_context *next;
-};
-
-#define INIT_AIO_CONTEXT { .reply_fd	= -1, \
-			   .next	= NULL }
-
-extern int submit_aio(enum aio_type type, int fd, char *buf, int len,
-		      unsigned long long offset, int reply_fd,
-                      struct aio_context *aio);
-
-#endif
diff --git a/arch/um/include/shared/arch.h b/arch/um/include/shared/arch.h
index 4f46abd..880ee42 100644
--- a/arch/um/include/shared/arch.h
+++ b/arch/um/include/shared/arch.h
@@ -1,6 +1,6 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * Copyright (C) 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
- * Licensed under the GPL
  */
 
 #ifndef __ARCH_H__
diff --git a/arch/um/include/shared/as-layout.h b/arch/um/include/shared/as-layout.h
index ca1843e..5f286ef 100644
--- a/arch/um/include/shared/as-layout.h
+++ b/arch/um/include/shared/as-layout.h
@@ -1,6 +1,6 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * Copyright (C) 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
- * Licensed under the GPL
  */
 
 #ifndef __START_H__
diff --git a/arch/um/include/shared/elf_user.h b/arch/um/include/shared/elf_user.h
index 53516b6..fd461ee 100644
--- a/arch/um/include/shared/elf_user.h
+++ b/arch/um/include/shared/elf_user.h
@@ -1,7 +1,7 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * Copyright (C) 2004 Fujitsu Siemens Computers GmbH
  * Author: Bodo Stroesser <bstroesser@fujitsu-siemens.com>
- * Licensed under the GPL
  */
 
 #ifndef __ELF_USER_H__
diff --git a/arch/um/include/shared/frame_kern.h b/arch/um/include/shared/frame_kern.h
index a5cde5c..ed952ac 100644
--- a/arch/um/include/shared/frame_kern.h
+++ b/arch/um/include/shared/frame_kern.h
@@ -1,6 +1,6 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /* 
  * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
- * Licensed under the GPL
  */
 
 #ifndef __FRAME_KERN_H_
diff --git a/arch/um/include/shared/irq_kern.h b/arch/um/include/shared/irq_kern.h
index e05bd66..7cd1a10 100644
--- a/arch/um/include/shared/irq_kern.h
+++ b/arch/um/include/shared/irq_kern.h
@@ -1,6 +1,6 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * Copyright (C) 2001, 2002 Jeff Dike (jdike@karaya.com)
- * Licensed under the GPL
  */
 
 #ifndef __IRQ_KERN_H__
diff --git a/arch/um/include/shared/irq_user.h b/arch/um/include/shared/irq_user.h
index a7a6120..107751d 100644
--- a/arch/um/include/shared/irq_user.h
+++ b/arch/um/include/shared/irq_user.h
@@ -1,6 +1,6 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
- * Licensed under the GPL
  */
 
 #ifndef __IRQ_USER_H__
@@ -31,7 +31,6 @@
 struct siginfo;
 extern void sigio_handler(int sig, struct siginfo *unused_si, struct uml_pt_regs *regs);
 extern void free_irq_by_fd(int fd);
-extern void reactivate_fd(int fd, int irqnum);
 extern void deactivate_fd(int fd, int irqnum);
 extern int deactivate_all_fds(void);
 extern int activate_ipi(int fd, int pid);
diff --git a/arch/um/include/shared/kern.h b/arch/um/include/shared/kern.h
index 6cd0124..3a9c75a 100644
--- a/arch/um/include/shared/kern.h
+++ b/arch/um/include/shared/kern.h
@@ -1,6 +1,6 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /* 
  * Copyright (C) 2000 Jeff Dike (jdike@karaya.com)
- * Licensed under the GPL
  */
 
 #ifndef __KERN_H__
diff --git a/arch/um/include/shared/kern_util.h b/arch/um/include/shared/kern_util.h
index 35ab97e..ccafb62 100644
--- a/arch/um/include/shared/kern_util.h
+++ b/arch/um/include/shared/kern_util.h
@@ -1,6 +1,6 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
- * Licensed under the GPL
  */
 
 #ifndef __KERN_UTIL_H__
diff --git a/arch/um/include/shared/longjmp.h b/arch/um/include/shared/longjmp.h
index b3315c1..85a1cc2 100644
--- a/arch/um/include/shared/longjmp.h
+++ b/arch/um/include/shared/longjmp.h
@@ -18,7 +18,7 @@
 	enable = get_signals(); \
 	n = setjmp(*buf); \
 	if(n != 0) \
-		set_signals(enable); \
+		set_signals_trace(enable); \
 	n; })
 
 #endif
diff --git a/arch/um/include/shared/mem.h b/arch/um/include/shared/mem.h
index 5cd40e9..4862c91 100644
--- a/arch/um/include/shared/mem.h
+++ b/arch/um/include/shared/mem.h
@@ -1,6 +1,6 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /* 
  * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
- * Licensed under the GPL
  */
 
 #ifndef __MEM_H__
diff --git a/arch/um/include/shared/net_kern.h b/arch/um/include/shared/net_kern.h
index 40442b9..a87be13 100644
--- a/arch/um/include/shared/net_kern.h
+++ b/arch/um/include/shared/net_kern.h
@@ -1,6 +1,6 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * Copyright (C) 2002 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
- * Licensed under the GPL
  */
 
 #ifndef __UM_NET_KERN_H
diff --git a/arch/um/include/shared/net_user.h b/arch/um/include/shared/net_user.h
index 3dabbe1..1b05317 100644
--- a/arch/um/include/shared/net_user.h
+++ b/arch/um/include/shared/net_user.h
@@ -1,6 +1,6 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
- * Licensed under the GPL
  */
 
 #ifndef __UM_NET_USER_H__
diff --git a/arch/um/include/shared/os.h b/arch/um/include/shared/os.h
index 048ae37..506bcd1 100644
--- a/arch/um/include/shared/os.h
+++ b/arch/um/include/shared/os.h
@@ -1,8 +1,8 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * Copyright (C) 2015 Anton Ivanov (aivanov@{brocade.com,kot-begemot.co.uk})
  * Copyright (C) 2015 Thomas Meyer (thomas@m3y3r.de)
  * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
- * Licensed under the GPL
  */
 
 #ifndef __OS_H__
@@ -36,6 +36,8 @@
 #define OS_LIB_PATH	"/usr/lib/"
 #endif
 
+#define OS_SENDMSG_MAX_FDS 8
+
 /*
  * types taken from stat_file() in hostfs_user.c
  * (if they are wrong here, they are wrong there...).
@@ -175,6 +177,10 @@
 extern unsigned os_major(unsigned long long dev);
 extern unsigned os_minor(unsigned long long dev);
 extern unsigned long long os_makedev(unsigned major, unsigned minor);
+extern int os_falloc_punch(int fd, unsigned long long offset, int count);
+extern int os_eventfd(unsigned int initval, int flags);
+extern int os_sendmsg_fds(int fd, const void *buf, unsigned int len,
+			  const int *fds, unsigned int fds_num);
 
 /* start_up.c */
 extern void os_early_checks(void);
@@ -231,6 +237,7 @@
 extern void unblock_signals(void);
 extern int get_signals(void);
 extern int set_signals(int enable);
+extern int set_signals_trace(int enable);
 extern int os_is_signal_stack(void);
 extern void deliver_alarm(void);
 
@@ -249,15 +256,13 @@
 
 /* time.c */
 extern void os_idle_sleep(unsigned long long nsecs);
-extern int os_timer_create(void* timer);
-extern int os_timer_set_interval(void* timer, void* its);
-extern int os_timer_one_shot(int ticks);
-extern long long os_timer_disable(void);
-extern long os_timer_remain(void* timer);
+extern int os_timer_create(void);
+extern int os_timer_set_interval(unsigned long long nsecs);
+extern int os_timer_one_shot(unsigned long long nsecs);
+extern void os_timer_disable(void);
 extern void uml_idle_timer(void);
 extern long long os_persistent_clock_emulation(void);
 extern long long os_nsecs(void);
-extern long long os_vnsecs(void);
 
 /* skas/mem.c */
 extern long run_syscall_stub(struct mm_id * mm_idp,
@@ -318,4 +323,10 @@
 
 long syscall(long number, ...);
 
+/* irqflags tracing */
+extern void block_signals_trace(void);
+extern void unblock_signals_trace(void);
+extern void um_trace_signals_on(void);
+extern void um_trace_signals_off(void);
+
 #endif
diff --git a/arch/um/include/shared/ptrace_user.h b/arch/um/include/shared/ptrace_user.h
index 56b2f28..95455e8 100644
--- a/arch/um/include/shared/ptrace_user.h
+++ b/arch/um/include/shared/ptrace_user.h
@@ -1,6 +1,6 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /* 
  * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
- * Licensed under the GPL
  */
 
 #ifndef __PTRACE_USER_H__
diff --git a/arch/um/include/shared/registers.h b/arch/um/include/shared/registers.h
index a74449b..0c50fa6 100644
--- a/arch/um/include/shared/registers.h
+++ b/arch/um/include/shared/registers.h
@@ -1,6 +1,6 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * Copyright (C) 2004 PathScale, Inc
- * Licensed under the GPL
  */
 
 #ifndef __REGISTERS_H
diff --git a/arch/um/include/shared/sigio.h b/arch/um/include/shared/sigio.h
index 434f1a9..8fe8f57 100644
--- a/arch/um/include/shared/sigio.h
+++ b/arch/um/include/shared/sigio.h
@@ -1,6 +1,6 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /* 
  * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
- * Licensed under the GPL
  */
 
 #ifndef __SIGIO_H__
diff --git a/arch/um/include/shared/skas/mm_id.h b/arch/um/include/shared/skas/mm_id.h
index 48dd098..4337b4c 100644
--- a/arch/um/include/shared/skas/mm_id.h
+++ b/arch/um/include/shared/skas/mm_id.h
@@ -1,6 +1,6 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * Copyright (C) 2005 Jeff Dike (jdike@karaya.com)
- * Licensed under the GPL
  */
 
 #ifndef __MM_ID_H
diff --git a/arch/um/include/shared/skas/skas.h b/arch/um/include/shared/skas/skas.h
index 911f3c4..c93d2cb 100644
--- a/arch/um/include/shared/skas/skas.h
+++ b/arch/um/include/shared/skas/skas.h
@@ -1,6 +1,6 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
- * Licensed under the GPL
  */
 
 #ifndef __SKAS_H
diff --git a/arch/um/include/shared/skas/stub-data.h b/arch/um/include/shared/skas/stub-data.h
index 13f404e..6b01d97 100644
--- a/arch/um/include/shared/skas/stub-data.h
+++ b/arch/um/include/shared/skas/stub-data.h
@@ -1,8 +1,8 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
 
  * Copyright (C) 2015 Thomas Meyer (thomas@m3y3r.de)
  * Copyright (C) 2005 Jeff Dike (jdike@karaya.com)
- * Licensed under the GPL
  */
 
 #ifndef __STUB_DATA_H
diff --git a/arch/um/include/shared/timer-internal.h b/arch/um/include/shared/timer-internal.h
index 03e6f21..2d2d13c 100644
--- a/arch/um/include/shared/timer-internal.h
+++ b/arch/um/include/shared/timer-internal.h
@@ -1,7 +1,7 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * Copyright (C) 2012 - 2014 Cisco Systems
  * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
- * Licensed under the GPL
  */
 
 #ifndef __TIMER_INTERNAL_H__
@@ -10,4 +10,67 @@
 #define TIMER_MULTIPLIER 256
 #define TIMER_MIN_DELTA  500
 
+enum time_travel_mode {
+	TT_MODE_OFF,
+	TT_MODE_BASIC,
+	TT_MODE_INFCPU,
+};
+
+enum time_travel_timer_mode {
+	TT_TMR_DISABLED,
+	TT_TMR_ONESHOT,
+	TT_TMR_PERIODIC,
+};
+
+#ifdef CONFIG_UML_TIME_TRAVEL_SUPPORT
+extern enum time_travel_mode time_travel_mode;
+extern unsigned long long time_travel_time;
+extern enum time_travel_timer_mode time_travel_timer_mode;
+extern unsigned long long time_travel_timer_expiry;
+extern unsigned long long time_travel_timer_interval;
+
+static inline void time_travel_set_time(unsigned long long ns)
+{
+	time_travel_time = ns;
+}
+
+static inline void time_travel_set_timer_mode(enum time_travel_timer_mode mode)
+{
+	time_travel_timer_mode = mode;
+}
+
+static inline void time_travel_set_timer_expiry(unsigned long long expiry)
+{
+	time_travel_timer_expiry = expiry;
+}
+
+static inline void time_travel_set_timer_interval(unsigned long long interval)
+{
+	time_travel_timer_interval = interval;
+}
+#else
+#define time_travel_mode TT_MODE_OFF
+#define time_travel_time 0
+#define time_travel_timer_expiry 0
+#define time_travel_timer_interval 0
+
+static inline void time_travel_set_time(unsigned long long ns)
+{
+}
+
+static inline void time_travel_set_timer_mode(enum time_travel_timer_mode mode)
+{
+}
+
+static inline void time_travel_set_timer_expiry(unsigned long long expiry)
+{
+}
+
+static inline void time_travel_set_timer_interval(unsigned long long interval)
+{
+}
+
+#define time_travel_timer_mode TT_TMR_DISABLED
+#endif
+
 #endif
diff --git a/arch/um/include/shared/um_malloc.h b/arch/um/include/shared/um_malloc.h
index 6395fef..13da932 100644
--- a/arch/um/include/shared/um_malloc.h
+++ b/arch/um/include/shared/um_malloc.h
@@ -1,6 +1,6 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * Copyright (C) 2005 Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
- * Licensed under the GPL
  */
 
 #ifndef __UM_MALLOC_H__
diff --git a/arch/um/include/shared/user.h b/arch/um/include/shared/user.h
index 4cff19f..e793e42 100644
--- a/arch/um/include/shared/user.h
+++ b/arch/um/include/shared/user.h
@@ -1,6 +1,6 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /* 
  * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
- * Licensed under the GPL
  */
 
 #ifndef __USER_H__