Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

82 files changed, 5276 insertions, 0 deletions

diff --git a/arch/x86/um/Kconfig b/arch/x86/um/Kconfig
new file mode 100644
index 0000000000..186f132684
--- /dev/null
+++ b/arch/x86/um/Kconfig
@@ -0,0 +1,49 @@
+# SPDX-License-Identifier: GPL-2.0
+
+menu "Host processor type and features"
+
+source "arch/x86/Kconfig.cpu"
+
+endmenu
+
+config UML_X86
+	def_bool y
+	select ARCH_BINFMT_ELF_EXTRA_PHDRS if X86_32
+	select DCACHE_WORD_ACCESS
+
+config 64BIT
+	bool "64-bit kernel" if "$(SUBARCH)" = "x86"
+	default "$(SUBARCH)" != "i386"
+
+config X86_32
+	def_bool !64BIT
+	select ARCH_32BIT_OFF_T
+	select ARCH_WANT_IPC_PARSE_VERSION
+	select MODULES_USE_ELF_REL
+	select CLONE_BACKWARDS
+	select OLD_SIGSUSPEND3
+	select OLD_SIGACTION
+
+config X86_64
+	def_bool 64BIT
+	select MODULES_USE_ELF_RELA
+
+config 3_LEVEL_PGTABLES
+	bool "Three-level pagetables" if !64BIT
+	default 64BIT
+	help
+	  Three-level pagetables will let UML have more than 4G of physical
+	  memory.  All the memory that can't be mapped directly will be treated
+	  as high memory.
+
+	  However, this it experimental on 32-bit architectures, so if unsure say
+	  N (on x86-64 it's automatically enabled, instead, as it's safe there).
+
+config ARCH_HAS_SC_SIGNALS
+	def_bool !64BIT
+
+config ARCH_REUSE_HOST_VSYSCALL_AREA
+	def_bool !64BIT
+
+config GENERIC_HWEIGHT
+	def_bool y
diff --git a/arch/x86/um/Makefile b/arch/x86/um/Makefile
new file mode 100644
index 0000000000..8bc72a51b2
--- /dev/null
+++ b/arch/x86/um/Makefile
@@ -0,0 +1,52 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+#
+
+ifeq ($(CONFIG_X86_32),y)
+	BITS := 32
+else
+	BITS := 64
+endif
+
+obj-y = bugs_$(BITS).o delay.o fault.o ldt.o \
+	ptrace_$(BITS).o ptrace_user.o setjmp_$(BITS).o signal.o \
+	stub_$(BITS).o stub_segv.o \
+	sys_call_table_$(BITS).o sysrq_$(BITS).o tls_$(BITS).o \
+	mem_$(BITS).o subarch.o os-Linux/
+
+ifeq ($(CONFIG_X86_32),y)
+
+obj-y += syscalls_32.o
+obj-$(CONFIG_ELF_CORE) += elfcore.o
+
+subarch-y = ../lib/string_32.o ../lib/atomic64_32.o ../lib/atomic64_cx8_32.o
+subarch-y += ../lib/cmpxchg8b_emu.o ../lib/atomic64_386_32.o
+subarch-y += ../lib/checksum_32.o
+subarch-y += ../kernel/sys_ia32.o
+
+else
+
+obj-y += syscalls_64.o vdso/
+
+subarch-y = ../lib/csum-partial_64.o ../lib/memcpy_64.o \
+	../lib/memmove_64.o ../lib/memset_64.o
+subarch-$(CONFIG_PREEMPTION) += ../entry/thunk_64.o
+
+endif
+
+subarch-$(CONFIG_MODULES) += ../kernel/module.o
+
+USER_OBJS := bugs_$(BITS).o ptrace_user.o fault.o
+
+$(obj)/user-offsets.s: c_flags = -Wp,-MD,$(depfile) $(USER_CFLAGS) \
+	-Iarch/x86/include/generated
+targets += user-offsets.s
+
+include/generated/user_constants.h: $(obj)/user-offsets.s FORCE
+	$(call filechk,offsets,__USER_CONSTANT_H__)
+
+UNPROFILE_OBJS := stub_segv.o
+CFLAGS_stub_segv.o := $(CFLAGS_NO_HARDENING)
+
+include $(srctree)/arch/um/scripts/Makefile.rules
diff --git a/arch/x86/um/asm/apic.h b/arch/x86/um/asm/apic.h
new file mode 100644
index 0000000000..876dee84ab
--- /dev/null
+++ b/arch/x86/um/asm/apic.h
@@ -0,0 +1,4 @@
+#ifndef __UM_APIC_H
+#define __UM_APIC_H
+
+#endif
diff --git a/arch/x86/um/asm/arch_hweight.h b/arch/x86/um/asm/arch_hweight.h
new file mode 100644
index 0000000000..0d2d5fbb3a
--- /dev/null
+++ b/arch/x86/um/asm/arch_hweight.h
@@ -0,0 +1,7 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_UM_HWEIGHT_H
+#define _ASM_UM_HWEIGHT_H
+
+#include <asm-generic/bitops/arch_hweight.h>
+
+#endif
diff --git a/arch/x86/um/asm/archparam.h b/arch/x86/um/asm/archparam.h
new file mode 100644
index 0000000000..c17cf68dda
--- /dev/null
+++ b/arch/x86/um/asm/archparam.h
@@ -0,0 +1,20 @@
+/* 
+ * Copyright (C) 2000 - 2003 Jeff Dike (jdike@addtoit.com)
+ * Copyright 2003 PathScale, Inc.
+ * Licensed under the GPL
+ */
+
+#ifndef __UM_ARCHPARAM_H
+#define __UM_ARCHPARAM_H
+
+#ifdef CONFIG_X86_32
+
+#ifdef CONFIG_X86_PAE
+#define LAST_PKMAP 512
+#else
+#define LAST_PKMAP 1024
+#endif
+
+#endif
+
+#endif
diff --git a/arch/x86/um/asm/barrier.h b/arch/x86/um/asm/barrier.h
new file mode 100644
index 0000000000..4da3369656
--- /dev/null
+++ b/arch/x86/um/asm/barrier.h
@@ -0,0 +1,29 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_UM_BARRIER_H_
+#define _ASM_UM_BARRIER_H_
+
+#include <asm/cpufeatures.h>
+#include <asm/alternative.h>
+
+/*
+ * Force strict CPU ordering.
+ * And yes, this is required on UP too when we're talking
+ * to devices.
+ */
+#ifdef CONFIG_X86_32
+
+#define mb()	alternative("lock; addl $0,0(%%esp)", "mfence", X86_FEATURE_XMM2)
+#define rmb()	alternative("lock; addl $0,0(%%esp)", "lfence", X86_FEATURE_XMM2)
+#define wmb()	alternative("lock; addl $0,0(%%esp)", "sfence", X86_FEATURE_XMM)
+
+#else /* CONFIG_X86_32 */
+
+#define mb()	asm volatile("mfence" : : : "memory")
+#define rmb()	asm volatile("lfence" : : : "memory")
+#define wmb()	asm volatile("sfence" : : : "memory")
+
+#endif /* CONFIG_X86_32 */
+
+#include <asm-generic/barrier.h>
+
+#endif
diff --git a/arch/x86/um/asm/checksum.h b/arch/x86/um/asm/checksum.h
new file mode 100644
index 0000000000..b078245003
--- /dev/null
+++ b/arch/x86/um/asm/checksum.h
@@ -0,0 +1,119 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __UM_CHECKSUM_H
+#define __UM_CHECKSUM_H
+
+#include <linux/string.h>
+#include <linux/in6.h>
+#include <linux/uaccess.h>
+
+/*
+ * computes the checksum of a memory block at buff, length len,
+ * and adds in "sum" (32-bit)
+ *
+ * returns a 32-bit number suitable for feeding into itself
+ * or csum_tcpudp_magic
+ *
+ * this function must be called with even lengths, except
+ * for the last fragment, which may be odd
+ *
+ * it's best to have buff aligned on a 32-bit boundary
+ */
+extern __wsum csum_partial(const void *buff, int len, __wsum sum);
+
+/**
+ * csum_fold - Fold and invert a 32bit checksum.
+ * sum: 32bit unfolded sum
+ *
+ * Fold a 32bit running checksum to 16bit and invert it. This is usually
+ * the last step before putting a checksum into a packet.
+ * Make sure not to mix with 64bit checksums.
+ */
+static inline __sum16 csum_fold(__wsum sum)
+{
+	__asm__(
+		"  addl %1,%0\n"
+		"  adcl $0xffff,%0"
+		: "=r" (sum)
+		: "r" ((__force u32)sum << 16),
+		  "0" ((__force u32)sum & 0xffff0000)
+	);
+	return (__force __sum16)(~(__force u32)sum >> 16);
+}
+
+/**
+ * csum_tcpup_nofold - Compute an IPv4 pseudo header checksum.
+ * @saddr: source address
+ * @daddr: destination address
+ * @len: length of packet
+ * @proto: ip protocol of packet
+ * @sum: initial sum to be added in (32bit unfolded)
+ *
+ * Returns the pseudo header checksum the input data. Result is
+ * 32bit unfolded.
+ */
+static inline __wsum
+csum_tcpudp_nofold(__be32 saddr, __be32 daddr, __u32 len,
+		  __u8 proto, __wsum sum)
+{
+	asm("  addl %1, %0\n"
+	    "  adcl %2, %0\n"
+	    "  adcl %3, %0\n"
+	    "  adcl $0, %0\n"
+		: "=r" (sum)
+	    : "g" (daddr), "g" (saddr), "g" ((len + proto) << 8), "0" (sum));
+	return sum;
+}
+
+/*
+ * computes the checksum of the TCP/UDP pseudo-header
+ * returns a 16-bit checksum, already complemented
+ */
+static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr,
+					__u32 len, __u8 proto,
+					__wsum sum)
+{
+	return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,sum));
+}
+
+/**
+ * ip_fast_csum - Compute the IPv4 header checksum efficiently.
+ * iph: ipv4 header
+ * ihl: length of header / 4
+ */
+static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl)
+{
+	unsigned int sum;
+
+	asm(	"  movl (%1), %0\n"
+		"  subl $4, %2\n"
+		"  jbe 2f\n"
+		"  addl 4(%1), %0\n"
+		"  adcl 8(%1), %0\n"
+		"  adcl 12(%1), %0\n"
+		"1: adcl 16(%1), %0\n"
+		"  lea 4(%1), %1\n"
+		"  decl %2\n"
+		"  jne	1b\n"
+		"  adcl $0, %0\n"
+		"  movl %0, %2\n"
+		"  shrl $16, %0\n"
+		"  addw %w2, %w0\n"
+		"  adcl $0, %0\n"
+		"  notl %0\n"
+		"2:"
+	/* Since the input registers which are loaded with iph and ipl
+	   are modified, we must also specify them as outputs, or gcc
+	   will assume they contain their original values. */
+	: "=r" (sum), "=r" (iph), "=r" (ihl)
+	: "1" (iph), "2" (ihl)
+	: "memory");
+	return (__force __sum16)sum;
+}
+
+#ifdef CONFIG_X86_32
+# include "checksum_32.h"
+#else
+# include "checksum_64.h"
+#endif
+
+#endif
diff --git a/arch/x86/um/asm/checksum_32.h b/arch/x86/um/asm/checksum_32.h
new file mode 100644
index 0000000000..0b13c2947a
--- /dev/null
+++ b/arch/x86/um/asm/checksum_32.h
@@ -0,0 +1,38 @@
+/*
+ * Licensed under the GPL
+ */
+
+#ifndef __UM_SYSDEP_CHECKSUM_H
+#define __UM_SYSDEP_CHECKSUM_H
+
+static inline __sum16 ip_compute_csum(const void *buff, int len)
+{
+    return csum_fold (csum_partial(buff, len, 0));
+}
+
+#define _HAVE_ARCH_IPV6_CSUM
+static __inline__ __sum16 csum_ipv6_magic(const struct in6_addr *saddr,
+					  const struct in6_addr *daddr,
+					  __u32 len, __u8 proto,
+					  __wsum sum)
+{
+	__asm__(
+		"addl 0(%1), %0		;\n"
+		"adcl 4(%1), %0		;\n"
+		"adcl 8(%1), %0		;\n"
+		"adcl 12(%1), %0	;\n"
+		"adcl 0(%2), %0		;\n"
+		"adcl 4(%2), %0		;\n"
+		"adcl 8(%2), %0		;\n"
+		"adcl 12(%2), %0	;\n"
+		"adcl %3, %0		;\n"
+		"adcl %4, %0		;\n"
+		"adcl $0, %0		;\n"
+		: "=&r" (sum)
+		: "r" (saddr), "r" (daddr),
+		  "r"(htonl(len)), "r"(htonl(proto)), "0"(sum));
+
+	return csum_fold(sum);
+}
+
+#endif
diff --git a/arch/x86/um/asm/checksum_64.h b/arch/x86/um/asm/checksum_64.h
new file mode 100644
index 0000000000..7b6cd19215
--- /dev/null
+++ b/arch/x86/um/asm/checksum_64.h
@@ -0,0 +1,19 @@
+/*
+ * Licensed under the GPL
+ */
+
+#ifndef __UM_SYSDEP_CHECKSUM_H
+#define __UM_SYSDEP_CHECKSUM_H
+
+static inline unsigned add32_with_carry(unsigned a, unsigned b)
+{
+        asm("addl %2,%0\n\t"
+            "adcl $0,%0"
+            : "=r" (a)
+            : "0" (a), "r" (b));
+        return a;
+}
+
+extern __sum16 ip_compute_csum(const void *buff, int len);
+
+#endif
diff --git a/arch/x86/um/asm/desc.h b/arch/x86/um/asm/desc.h
new file mode 100644
index 0000000000..34de4e93d9
--- /dev/null
+++ b/arch/x86/um/asm/desc.h
@@ -0,0 +1,17 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __UM_DESC_H
+#define __UM_DESC_H
+
+/* Taken from asm-i386/desc.h, it's the only thing we need. The rest wouldn't
+ * compile, and has never been used. */
+#define LDT_empty(info) (\
+	(info)->base_addr	== 0	&& \
+	(info)->limit		== 0	&& \
+	(info)->contents	== 0	&& \
+	(info)->read_exec_only	== 1	&& \
+	(info)->seg_32bit	== 0	&& \
+	(info)->limit_in_pages	== 0	&& \
+	(info)->seg_not_present	== 1	&& \
+	(info)->useable		== 0	)
+
+#endif
diff --git a/arch/x86/um/asm/elf.h b/arch/x86/um/asm/elf.h
new file mode 100644
index 0000000000..6523eb7c3b
--- /dev/null
+++ b/arch/x86/um/asm/elf.h
@@ -0,0 +1,213 @@
+/*
+ * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+ * Licensed under the GPL
+ */
+#ifndef __UM_ELF_X86_H
+#define __UM_ELF_X86_H
+
+#include <asm/user.h>
+#include <skas.h>
+
+#ifdef CONFIG_X86_32
+
+#define R_386_NONE	0
+#define R_386_32	1
+#define R_386_PC32	2
+#define R_386_GOT32	3
+#define R_386_PLT32	4
+#define R_386_COPY	5
+#define R_386_GLOB_DAT	6
+#define R_386_JMP_SLOT	7
+#define R_386_RELATIVE	8
+#define R_386_GOTOFF	9
+#define R_386_GOTPC	10
+#define R_386_NUM	11
+
+/*
+ * This is used to ensure we don't load something for the wrong architecture.
+ */
+#define elf_check_arch(x) \
+	(((x)->e_machine == EM_386) || ((x)->e_machine == EM_486))
+
+#define ELF_CLASS	ELFCLASS32
+#define ELF_DATA        ELFDATA2LSB
+#define ELF_ARCH        EM_386
+
+#define ELF_PLAT_INIT(regs, load_addr) do { \
+	PT_REGS_BX(regs) = 0; \
+	PT_REGS_CX(regs) = 0; \
+	PT_REGS_DX(regs) = 0; \
+	PT_REGS_SI(regs) = 0; \
+	PT_REGS_DI(regs) = 0; \
+	PT_REGS_BP(regs) = 0; \
+	PT_REGS_AX(regs) = 0; \
+} while (0)
+
+/* Shamelessly stolen from include/asm-i386/elf.h */
+
+#define ELF_CORE_COPY_REGS(pr_reg, regs) do {	\
+	pr_reg[0] = PT_REGS_BX(regs);		\
+	pr_reg[1] = PT_REGS_CX(regs);		\
+	pr_reg[2] = PT_REGS_DX(regs);		\
+	pr_reg[3] = PT_REGS_SI(regs);		\
+	pr_reg[4] = PT_REGS_DI(regs);		\
+	pr_reg[5] = PT_REGS_BP(regs);		\
+	pr_reg[6] = PT_REGS_AX(regs);		\
+	pr_reg[7] = PT_REGS_DS(regs);		\
+	pr_reg[8] = PT_REGS_ES(regs);		\
+	/* fake once used fs and gs selectors? */	\
+	pr_reg[9] = PT_REGS_DS(regs);		\
+	pr_reg[10] = PT_REGS_DS(regs);		\
+	pr_reg[11] = PT_REGS_SYSCALL_NR(regs);	\
+	pr_reg[12] = PT_REGS_IP(regs);		\
+	pr_reg[13] = PT_REGS_CS(regs);		\
+	pr_reg[14] = PT_REGS_EFLAGS(regs);	\
+	pr_reg[15] = PT_REGS_SP(regs);		\
+	pr_reg[16] = PT_REGS_SS(regs);		\
+} while (0);
+
+extern char * elf_aux_platform;
+#define ELF_PLATFORM (elf_aux_platform)
+
+extern unsigned long vsyscall_ehdr;
+extern unsigned long vsyscall_end;
+extern unsigned long __kernel_vsyscall;
+
+/*
+ * This is the range that is readable by user mode, and things
+ * acting like user mode such as get_user_pages.
+ */
+#define FIXADDR_USER_START      vsyscall_ehdr
+#define FIXADDR_USER_END        vsyscall_end
+
+
+/*
+ * Architecture-neutral AT_ values in 0-17, leave some room
+ * for more of them, start the x86-specific ones at 32.
+ */
+#define AT_SYSINFO		32
+#define AT_SYSINFO_EHDR		33
+
+#define ARCH_DLINFO						\
+do {								\
+	if ( vsyscall_ehdr ) {					\
+		NEW_AUX_ENT(AT_SYSINFO,	__kernel_vsyscall);	\
+		NEW_AUX_ENT(AT_SYSINFO_EHDR, vsyscall_ehdr);	\
+	}							\
+} while (0)
+
+#else
+
+/* x86-64 relocation types, taken from asm-x86_64/elf.h */
+#define R_X86_64_NONE		0	/* No reloc */
+#define R_X86_64_64		1	/* Direct 64 bit  */
+#define R_X86_64_PC32		2	/* PC relative 32 bit signed */
+#define R_X86_64_GOT32		3	/* 32 bit GOT entry */
+#define R_X86_64_PLT32		4	/* 32 bit PLT address */
+#define R_X86_64_COPY		5	/* Copy symbol at runtime */
+#define R_X86_64_GLOB_DAT	6	/* Create GOT entry */
+#define R_X86_64_JUMP_SLOT	7	/* Create PLT entry */
+#define R_X86_64_RELATIVE	8	/* Adjust by program base */
+#define R_X86_64_GOTPCREL	9	/* 32 bit signed pc relative
+					   offset to GOT */
+#define R_X86_64_32		10	/* Direct 32 bit zero extended */
+#define R_X86_64_32S		11	/* Direct 32 bit sign extended */
+#define R_X86_64_16		12	/* Direct 16 bit zero extended */
+#define R_X86_64_PC16		13	/* 16 bit sign extended pc relative */
+#define R_X86_64_8		14	/* Direct 8 bit sign extended  */
+#define R_X86_64_PC8		15	/* 8 bit sign extended pc relative */
+#define R_X86_64_PC64		24	/* Place relative 64-bit signed */
+
+/*
+ * This is used to ensure we don't load something for the wrong architecture.
+ */
+#define elf_check_arch(x) \
+	((x)->e_machine == EM_X86_64)
+
+#define ELF_CLASS	ELFCLASS64
+#define ELF_DATA        ELFDATA2LSB
+#define ELF_ARCH        EM_X86_64
+
+#define ELF_PLAT_INIT(regs, load_addr)    do { \
+	PT_REGS_BX(regs) = 0; \
+	PT_REGS_CX(regs) = 0; \
+	PT_REGS_DX(regs) = 0; \
+	PT_REGS_SI(regs) = 0; \
+	PT_REGS_DI(regs) = 0; \
+	PT_REGS_BP(regs) = 0; \
+	PT_REGS_AX(regs) = 0; \
+	PT_REGS_R8(regs) = 0; \
+	PT_REGS_R9(regs) = 0; \
+	PT_REGS_R10(regs) = 0; \
+	PT_REGS_R11(regs) = 0; \
+	PT_REGS_R12(regs) = 0; \
+	PT_REGS_R13(regs) = 0; \
+	PT_REGS_R14(regs) = 0; \
+	PT_REGS_R15(regs) = 0; \
+} while (0)
+
+#define ELF_CORE_COPY_REGS(pr_reg, _regs)		\
+	(pr_reg)[0] = (_regs)->regs.gp[0];			\
+	(pr_reg)[1] = (_regs)->regs.gp[1];			\
+	(pr_reg)[2] = (_regs)->regs.gp[2];			\
+	(pr_reg)[3] = (_regs)->regs.gp[3];			\
+	(pr_reg)[4] = (_regs)->regs.gp[4];			\
+	(pr_reg)[5] = (_regs)->regs.gp[5];			\
+	(pr_reg)[6] = (_regs)->regs.gp[6];			\
+	(pr_reg)[7] = (_regs)->regs.gp[7];			\
+	(pr_reg)[8] = (_regs)->regs.gp[8];			\
+	(pr_reg)[9] = (_regs)->regs.gp[9];			\
+	(pr_reg)[10] = (_regs)->regs.gp[10];			\
+	(pr_reg)[11] = (_regs)->regs.gp[11];			\
+	(pr_reg)[12] = (_regs)->regs.gp[12];			\
+	(pr_reg)[13] = (_regs)->regs.gp[13];			\
+	(pr_reg)[14] = (_regs)->regs.gp[14];			\
+	(pr_reg)[15] = (_regs)->regs.gp[15];			\
+	(pr_reg)[16] = (_regs)->regs.gp[16];			\
+	(pr_reg)[17] = (_regs)->regs.gp[17];			\
+	(pr_reg)[18] = (_regs)->regs.gp[18];			\
+	(pr_reg)[19] = (_regs)->regs.gp[19];			\
+	(pr_reg)[20] = (_regs)->regs.gp[20];			\
+	(pr_reg)[21] = current->thread.arch.fs;			\
+	(pr_reg)[22] = 0;					\
+	(pr_reg)[23] = 0;					\
+	(pr_reg)[24] = 0;					\
+	(pr_reg)[25] = 0;					\
+	(pr_reg)[26] = 0;
+
+#define ELF_PLATFORM "x86_64"
+
+/* No user-accessible fixmap addresses, i.e. vsyscall */
+#define FIXADDR_USER_START      0
+#define FIXADDR_USER_END        0
+
+#define ARCH_HAS_SETUP_ADDITIONAL_PAGES 1
+struct linux_binprm;
+extern int arch_setup_additional_pages(struct linux_binprm *bprm,
+	int uses_interp);
+
+extern unsigned long um_vdso_addr;
+#define AT_SYSINFO_EHDR 33
+#define ARCH_DLINFO	NEW_AUX_ENT(AT_SYSINFO_EHDR, um_vdso_addr)
+
+#endif
+
+typedef unsigned long elf_greg_t;
+
+#define ELF_NGREG (sizeof(struct user_regs_struct) / sizeof(elf_greg_t))
+typedef elf_greg_t elf_gregset_t[ELF_NGREG];
+
+typedef struct user_i387_struct elf_fpregset_t;
+
+struct task_struct;
+
+#define ELF_EXEC_PAGESIZE 4096
+
+#define ELF_ET_DYN_BASE (TASK_SIZE / 3 * 2)
+
+extern long elf_aux_hwcap;
+#define ELF_HWCAP (elf_aux_hwcap)
+
+#define SET_PERSONALITY(ex) do {} while(0)
+
+#endif
diff --git a/arch/x86/um/asm/irq_vectors.h b/arch/x86/um/asm/irq_vectors.h
new file mode 100644
index 0000000000..272a81e0ce
--- /dev/null
+++ b/arch/x86/um/asm/irq_vectors.h
@@ -0,0 +1,10 @@
+/* 
+ * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
+ * Licensed under the GPL
+ */
+
+#ifndef __UM_IRQ_VECTORS_H
+#define __UM_IRQ_VECTORS_H
+
+#endif
+
diff --git a/arch/x86/um/asm/mm_context.h b/arch/x86/um/asm/mm_context.h
new file mode 100644
index 0000000000..dc32dc023c
--- /dev/null
+++ b/arch/x86/um/asm/mm_context.h
@@ -0,0 +1,70 @@
+/*
+ * Copyright (C) 2004 Fujitsu Siemens Computers GmbH
+ * Licensed under the GPL
+ *
+ * Author: Bodo Stroesser <bstroesser@fujitsu-siemens.com>
+ */
+
+#ifndef __ASM_LDT_H
+#define __ASM_LDT_H
+
+#include <linux/mutex.h>
+#include <asm/ldt.h>
+
+#define LDT_PAGES_MAX \
+	((LDT_ENTRIES * LDT_ENTRY_SIZE)/PAGE_SIZE)
+#define LDT_ENTRIES_PER_PAGE \
+	(PAGE_SIZE/LDT_ENTRY_SIZE)
+#define LDT_DIRECT_ENTRIES \
+	((LDT_PAGES_MAX*sizeof(void *))/LDT_ENTRY_SIZE)
+
+struct ldt_entry {
+	__u32 a;
+	__u32 b;
+};
+
+typedef struct uml_ldt {
+	int entry_count;
+	struct mutex lock;
+	union {
+		struct ldt_entry * pages[LDT_PAGES_MAX];
+		struct ldt_entry entries[LDT_DIRECT_ENTRIES];
+	} u;
+} uml_ldt_t;
+
+#define LDT_entry_a(info) \
+	((((info)->base_addr & 0x0000ffff) << 16) | ((info)->limit & 0x0ffff))
+
+#define LDT_entry_b(info) \
+	(((info)->base_addr & 0xff000000) | \
+	(((info)->base_addr & 0x00ff0000) >> 16) | \
+	((info)->limit & 0xf0000) | \
+	(((info)->read_exec_only ^ 1) << 9) | \
+	((info)->contents << 10) | \
+	(((info)->seg_not_present ^ 1) << 15) | \
+	((info)->seg_32bit << 22) | \
+	((info)->limit_in_pages << 23) | \
+	((info)->useable << 20) | \
+	0x7000)
+
+#define _LDT_empty(info) (\
+	(info)->base_addr	== 0	&& \
+	(info)->limit		== 0	&& \
+	(info)->contents	== 0	&& \
+	(info)->read_exec_only	== 1	&& \
+	(info)->seg_32bit	== 0	&& \
+	(info)->limit_in_pages	== 0	&& \
+	(info)->seg_not_present	== 1	&& \
+	(info)->useable		== 0	)
+
+#ifdef CONFIG_X86_64
+#define LDT_empty(info) (_LDT_empty(info) && ((info)->lm == 0))
+#else
+#define LDT_empty(info) (_LDT_empty(info))
+#endif
+
+struct uml_arch_mm_context {
+	uml_ldt_t ldt;
+};
+
+#endif
diff --git a/arch/x86/um/asm/module.h b/arch/x86/um/asm/module.h
new file mode 100644
index 0000000000..a3b061d660
--- /dev/null
+++ b/arch/x86/um/asm/module.h
@@ -0,0 +1,24 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __UM_MODULE_H
+#define __UM_MODULE_H
+
+/* UML is simple */
+struct mod_arch_specific
+{
+};
+
+#ifdef CONFIG_X86_32
+
+#define Elf_Shdr Elf32_Shdr
+#define Elf_Sym Elf32_Sym
+#define Elf_Ehdr Elf32_Ehdr
+
+#else
+
+#define Elf_Shdr Elf64_Shdr
+#define Elf_Sym Elf64_Sym
+#define Elf_Ehdr Elf64_Ehdr
+
+#endif
+
+#endif
diff --git a/arch/x86/um/asm/processor.h b/arch/x86/um/asm/processor.h
new file mode 100644
index 0000000000..478710384b
--- /dev/null
+++ b/arch/x86/um/asm/processor.h
@@ -0,0 +1,43 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __UM_PROCESSOR_H
+#define __UM_PROCESSOR_H
+#include <linux/time-internal.h>
+
+/* include faultinfo structure */
+#include <sysdep/faultinfo.h>
+
+#ifdef CONFIG_X86_32
+# include "processor_32.h"
+#else
+# include "processor_64.h"
+#endif
+
+#define KSTK_EIP(tsk) KSTK_REG(tsk, HOST_IP)
+#define KSTK_ESP(tsk) KSTK_REG(tsk, HOST_SP)
+#define KSTK_EBP(tsk) KSTK_REG(tsk, HOST_BP)
+
+#define ARCH_IS_STACKGROW(address) \
+       (address + 65536 + 32 * sizeof(unsigned long) >= UPT_SP(&current->thread.regs.regs))
+
+#include <asm/user.h>
+
+/* REP NOP (PAUSE) is a good thing to insert into busy-wait loops. */
+static __always_inline void rep_nop(void)
+{
+	__asm__ __volatile__("rep;nop": : :"memory");
+}
+
+static __always_inline void cpu_relax(void)
+{
+	if (time_travel_mode == TT_MODE_INFCPU ||
+	    time_travel_mode == TT_MODE_EXTERNAL)
+		time_travel_ndelay(1);
+	else
+		rep_nop();
+}
+
+#define task_pt_regs(t) (&(t)->thread.regs)
+
+#include <asm/processor-generic.h>
+
+#endif
diff --git a/arch/x86/um/asm/processor_32.h b/arch/x86/um/asm/processor_32.h
new file mode 100644
index 0000000000..5fb1b8449a
--- /dev/null
+++ b/arch/x86/um/asm/processor_32.h
@@ -0,0 +1,53 @@
+/*
+ * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
+ * Licensed under the GPL
+ */
+
+#ifndef __UM_PROCESSOR_I386_H
+#define __UM_PROCESSOR_I386_H
+
+#include <linux/string.h>
+#include <asm/segment.h>
+#include <asm/ldt.h>
+
+extern int host_has_cmov;
+
+struct uml_tls_struct {
+	struct user_desc tls;
+	unsigned flushed:1;
+	unsigned present:1;
+};
+
+struct arch_thread {
+	struct uml_tls_struct tls_array[GDT_ENTRY_TLS_ENTRIES];
+	unsigned long debugregs[8];
+	int debugregs_seq;
+	struct faultinfo faultinfo;
+};
+
+#define INIT_ARCH_THREAD { \
+	.tls_array  		= { [ 0 ... GDT_ENTRY_TLS_ENTRIES - 1 ] = \
+				    { .present = 0, .flushed = 0 } }, \
+	.debugregs  		= { [ 0 ... 7 ] = 0 }, \
+	.debugregs_seq		= 0, \
+	.faultinfo		= { 0, 0, 0 } \
+}
+
+#define STACKSLOTS_PER_LINE 8
+
+static inline void arch_flush_thread(struct arch_thread *thread)
+{
+	/* Clear any TLS still hanging */
+	memset(&thread->tls_array, 0, sizeof(thread->tls_array));
+}
+
+static inline void arch_copy_thread(struct arch_thread *from,
+                                    struct arch_thread *to)
+{
+        memcpy(&to->tls_array, &from->tls_array, sizeof(from->tls_array));
+}
+
+#define current_sp() ({ void *sp; __asm__("movl %%esp, %0" : "=r" (sp) : ); sp; })
+#define current_bp() ({ unsigned long bp; __asm__("movl %%ebp, %0" : "=r" (bp) : ); bp; })
+
+#endif
diff --git a/arch/x86/um/asm/processor_64.h b/arch/x86/um/asm/processor_64.h
new file mode 100644
index 0000000000..1ef9c21877
--- /dev/null
+++ b/arch/x86/um/asm/processor_64.h
@@ -0,0 +1,37 @@
+/*
+ * Copyright 2003 PathScale, Inc.
+ *
+ * Licensed under the GPL
+ */
+
+#ifndef __UM_PROCESSOR_X86_64_H
+#define __UM_PROCESSOR_X86_64_H
+
+struct arch_thread {
+        unsigned long debugregs[8];
+        int debugregs_seq;
+        unsigned long fs;
+        struct faultinfo faultinfo;
+};
+
+#define INIT_ARCH_THREAD { .debugregs  		= { [ 0 ... 7 ] = 0 }, \
+			   .debugregs_seq	= 0, \
+			   .fs			= 0, \
+			   .faultinfo		= { 0, 0, 0 } }
+
+#define STACKSLOTS_PER_LINE 4
+
+static inline void arch_flush_thread(struct arch_thread *thread)
+{
+}
+
+static inline void arch_copy_thread(struct arch_thread *from,
+                                    struct arch_thread *to)
+{
+	to->fs = from->fs;
+}
+
+#define current_sp() ({ void *sp; __asm__("movq %%rsp, %0" : "=r" (sp) : ); sp; })
+#define current_bp() ({ unsigned long bp; __asm__("movq %%rbp, %0" : "=r" (bp) : ); bp; })
+
+#endif
diff --git a/arch/x86/um/asm/ptrace.h b/arch/x86/um/asm/ptrace.h
new file mode 100644
index 0000000000..83822fd422
--- /dev/null
+++ b/arch/x86/um/asm/ptrace.h
@@ -0,0 +1,87 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __UM_X86_PTRACE_H
+#define __UM_X86_PTRACE_H
+
+#include <linux/compiler.h>
+#ifndef CONFIG_X86_32
+#define __FRAME_OFFSETS /* Needed to get the R* macros */
+#endif
+#include <asm/ptrace-generic.h>
+
+#define user_mode(r) UPT_IS_USER(&(r)->regs)
+
+#define PT_REGS_AX(r) UPT_AX(&(r)->regs)
+#define PT_REGS_BX(r) UPT_BX(&(r)->regs)
+#define PT_REGS_CX(r) UPT_CX(&(r)->regs)
+#define PT_REGS_DX(r) UPT_DX(&(r)->regs)
+
+#define PT_REGS_SI(r) UPT_SI(&(r)->regs)
+#define PT_REGS_DI(r) UPT_DI(&(r)->regs)
+#define PT_REGS_BP(r) UPT_BP(&(r)->regs)
+#define PT_REGS_EFLAGS(r) UPT_EFLAGS(&(r)->regs)
+
+#define PT_REGS_CS(r) UPT_CS(&(r)->regs)
+#define PT_REGS_SS(r) UPT_SS(&(r)->regs)
+#define PT_REGS_DS(r) UPT_DS(&(r)->regs)
+#define PT_REGS_ES(r) UPT_ES(&(r)->regs)
+
+#define PT_REGS_ORIG_SYSCALL(r) PT_REGS_AX(r)
+#define PT_REGS_SYSCALL_RET(r) PT_REGS_AX(r)
+
+#define PT_FIX_EXEC_STACK(sp) do ; while(0)
+
+#define profile_pc(regs) PT_REGS_IP(regs)
+
+#define UPT_RESTART_SYSCALL(r) (UPT_IP(r) -= 2)
+#define PT_REGS_SET_SYSCALL_RETURN(r, res) (PT_REGS_AX(r) = (res))
+
+static inline long regs_return_value(struct pt_regs *regs)
+{
+	return PT_REGS_AX(regs);
+}
+
+/*
+ * Forward declaration to avoid including sysdep/tls.h, which causes a
+ * circular include, and compilation failures.
+ */
+struct user_desc;
+
+#ifdef CONFIG_X86_32
+
+extern int ptrace_get_thread_area(struct task_struct *child, int idx,
+                                  struct user_desc __user *user_desc);
+
+extern int ptrace_set_thread_area(struct task_struct *child, int idx,
+                                  struct user_desc __user *user_desc);
+
+#else
+
+#define PT_REGS_R8(r) UPT_R8(&(r)->regs)
+#define PT_REGS_R9(r) UPT_R9(&(r)->regs)
+#define PT_REGS_R10(r) UPT_R10(&(r)->regs)
+#define PT_REGS_R11(r) UPT_R11(&(r)->regs)
+#define PT_REGS_R12(r) UPT_R12(&(r)->regs)
+#define PT_REGS_R13(r) UPT_R13(&(r)->regs)
+#define PT_REGS_R14(r) UPT_R14(&(r)->regs)
+#define PT_REGS_R15(r) UPT_R15(&(r)->regs)
+
+#include <asm/errno.h>
+
+static inline int ptrace_get_thread_area(struct task_struct *child, int idx,
+                                         struct user_desc __user *user_desc)
+{
+        return -ENOSYS;
+}
+
+static inline int ptrace_set_thread_area(struct task_struct *child, int idx,
+                                         struct user_desc __user *user_desc)
+{
+        return -ENOSYS;
+}
+
+extern long arch_prctl(struct task_struct *task, int option,
+		       unsigned long __user *addr);
+
+#endif
+#define user_stack_pointer(regs) PT_REGS_SP(regs)
+#endif /* __UM_X86_PTRACE_H */
diff --git a/arch/x86/um/asm/required-features.h b/arch/x86/um/asm/required-features.h
new file mode 100644
index 0000000000..dfb967b2d2
--- /dev/null
+++ b/arch/x86/um/asm/required-features.h
@@ -0,0 +1,9 @@
+#ifndef __UM_REQUIRED_FEATURES_H
+#define __UM_REQUIRED_FEATURES_H
+
+/*
+ * Nothing to see, just need something for the i386 and x86_64 asm
+ * headers to include.
+ */
+
+#endif
diff --git a/arch/x86/um/asm/segment.h b/arch/x86/um/asm/segment.h
new file mode 100644
index 0000000000..2ef507bc69
--- /dev/null
+++ b/arch/x86/um/asm/segment.h
@@ -0,0 +1,11 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __UM_SEGMENT_H
+#define __UM_SEGMENT_H
+
+extern int host_gdt_entry_tls_min;
+
+#define GDT_ENTRY_TLS_ENTRIES 3
+#define GDT_ENTRY_TLS_MIN host_gdt_entry_tls_min
+#define GDT_ENTRY_TLS_MAX (GDT_ENTRY_TLS_MIN + GDT_ENTRY_TLS_ENTRIES - 1)
+
+#endif
diff --git a/arch/x86/um/asm/syscall.h b/arch/x86/um/asm/syscall.h
new file mode 100644
index 0000000000..56a2f0913e
--- /dev/null
+++ b/arch/x86/um/asm/syscall.h
@@ -0,0 +1,21 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __UM_ASM_SYSCALL_H
+#define __UM_ASM_SYSCALL_H
+
+#include <asm/syscall-generic.h>
+#include <uapi/linux/audit.h>
+
+typedef asmlinkage long (*sys_call_ptr_t)(unsigned long, unsigned long,
+					  unsigned long, unsigned long,
+					  unsigned long, unsigned long);
+
+static inline int syscall_get_arch(struct task_struct *task)
+{
+#ifdef CONFIG_X86_32
+	return AUDIT_ARCH_I386;
+#else
+	return AUDIT_ARCH_X86_64;
+#endif
+}
+
+#endif /* __UM_ASM_SYSCALL_H */
diff --git a/arch/x86/um/asm/vm-flags.h b/arch/x86/um/asm/vm-flags.h
new file mode 100644
index 0000000000..df7a3896f5
--- /dev/null
+++ b/arch/x86/um/asm/vm-flags.h
@@ -0,0 +1,19 @@
+/*
+ * Copyright (C) 2004 Jeff Dike (jdike@addtoit.com)
+ * Copyright 2003 PathScale, Inc.
+ * Licensed under the GPL
+ */
+
+#ifndef __VM_FLAGS_X86_H
+#define __VM_FLAGS_X86_H
+
+#ifdef CONFIG_X86_32
+
+#define VM_DATA_DEFAULT_FLAGS	VM_DATA_FLAGS_TSK_EXEC
+
+#else
+
+#define VM_STACK_DEFAULT_FLAGS (VM_GROWSDOWN | VM_DATA_FLAGS_EXEC)
+
+#endif
+#endif
diff --git a/arch/x86/um/bugs_32.c b/arch/x86/um/bugs_32.c
new file mode 100644
index 0000000000..33daff4dad
--- /dev/null
+++ b/arch/x86/um/bugs_32.c
@@ -0,0 +1,74 @@
+/*
+ * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+ * Licensed under the GPL
+ */
+
+#include <signal.h>
+#include <kern_util.h>
+#include <longjmp.h>
+#include <sysdep/ptrace.h>
+#include <generated/asm-offsets.h>
+
+/* Set during early boot */
+static int host_has_cmov = 1;
+static jmp_buf cmov_test_return;
+
+static void cmov_sigill_test_handler(int sig)
+{
+	host_has_cmov = 0;
+	longjmp(cmov_test_return, 1);
+}
+
+void arch_check_bugs(void)
+{
+	struct sigaction old, new;
+
+	printk(UM_KERN_INFO "Checking for host processor cmov support...");
+	new.sa_handler = cmov_sigill_test_handler;
+
+	/* Make sure that SIGILL is enabled after the handler longjmps back */
+	new.sa_flags = SA_NODEFER;
+	sigemptyset(&new.sa_mask);
+	sigaction(SIGILL, &new, &old);
+
+	if (setjmp(cmov_test_return) == 0) {
+		unsigned long foo = 0;
+		__asm__ __volatile__("cmovz %0, %1" : "=r" (foo) : "0" (foo));
+		printk(UM_KERN_CONT "Yes\n");
+	} else
+		printk(UM_KERN_CONT "No\n");
+
+	sigaction(SIGILL, &old, &new);
+}
+
+void arch_examine_signal(int sig, struct uml_pt_regs *regs)
+{
+	unsigned char tmp[2];
+
+	/*
+	 * This is testing for a cmov (0x0f 0x4x) instruction causing a
+	 * SIGILL in init.
+	 */
+	if ((sig != SIGILL) || (get_current_pid() != 1))
+		return;
+
+	if (copy_from_user_proc(tmp, (void *) UPT_IP(regs), 2)) {
+		printk(UM_KERN_ERR "SIGILL in init, could not read "
+		       "instructions!\n");
+		return;
+	}
+
+	if ((tmp[0] != 0x0f) || ((tmp[1] & 0xf0) != 0x40))
+		return;
+
+	if (host_has_cmov == 0)
+		printk(UM_KERN_ERR "SIGILL caused by cmov, which this "
+		       "processor doesn't implement.  Boot a filesystem "
+		       "compiled for older processors");
+	else if (host_has_cmov == 1)
+		printk(UM_KERN_ERR "SIGILL caused by cmov, which this "
+		       "processor claims to implement");
+	else
+		printk(UM_KERN_ERR "Bad value for host_has_cmov (%d)",
+			host_has_cmov);
+}
diff --git a/arch/x86/um/bugs_64.c b/arch/x86/um/bugs_64.c
new file mode 100644
index 0000000000..8cc8256c69
--- /dev/null
+++ b/arch/x86/um/bugs_64.c
@@ -0,0 +1,15 @@
+/*
+ * Copyright 2003 PathScale, Inc.
+ *
+ * Licensed under the GPL
+ */
+
+#include <sysdep/ptrace.h>
+
+void arch_check_bugs(void)
+{
+}
+
+void arch_examine_signal(int sig, struct uml_pt_regs *regs)
+{
+}
diff --git a/arch/x86/um/delay.c b/arch/x86/um/delay.c
new file mode 100644
index 0000000000..8d510ceb43
--- /dev/null
+++ b/arch/x86/um/delay.c
@@ -0,0 +1,57 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2011 Richard Weinberger <richrd@nod.at>
+ * Mostly copied from arch/x86/lib/delay.c
+ */
+
+#include <linux/export.h>
+#include <linux/kernel.h>
+#include <linux/delay.h>
+#include <asm/param.h>
+
+void __delay(unsigned long loops)
+{
+	asm volatile(
+		"test %0,%0\n"
+		"jz 3f\n"
+		"jmp 1f\n"
+
+		".align 16\n"
+		"1: jmp 2f\n"
+
+		".align 16\n"
+		"2: dec %0\n"
+		" jnz 2b\n"
+		"3: dec %0\n"
+
+		: /* we don't need output */
+		: "a" (loops)
+	);
+}
+EXPORT_SYMBOL(__delay);
+
+inline void __const_udelay(unsigned long xloops)
+{
+	int d0;
+
+	xloops *= 4;
+	asm("mull %%edx"
+		: "=d" (xloops), "=&a" (d0)
+		: "1" (xloops), "0"
+		(loops_per_jiffy * (HZ/4)));
+
+	__delay(++xloops);
+}
+EXPORT_SYMBOL(__const_udelay);
+
+void __udelay(unsigned long usecs)
+{
+	__const_udelay(usecs * 0x000010c7); /* 2**32 / 1000000 (rounded up) */
+}
+EXPORT_SYMBOL(__udelay);
+
+void __ndelay(unsigned long nsecs)
+{
+	__const_udelay(nsecs * 0x00005); /* 2**32 / 1000000000 (rounded up) */
+}
+EXPORT_SYMBOL(__ndelay);
diff --git a/arch/x86/um/elfcore.c b/arch/x86/um/elfcore.c
new file mode 100644
index 0000000000..650cdbbdaf
--- /dev/null
+++ b/arch/x86/um/elfcore.c
@@ -0,0 +1,77 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/elf.h>
+#include <linux/coredump.h>
+#include <linux/fs.h>
+#include <linux/mm.h>
+
+#include <asm/elf.h>
+
+
+Elf32_Half elf_core_extra_phdrs(struct coredump_params *cprm)
+{
+	return vsyscall_ehdr ? (((struct elfhdr *)vsyscall_ehdr)->e_phnum) : 0;
+}
+
+int elf_core_write_extra_phdrs(struct coredump_params *cprm, loff_t offset)
+{
+	if ( vsyscall_ehdr ) {
+		const struct elfhdr *const ehdrp =
+			(struct elfhdr *) vsyscall_ehdr;
+		const struct elf_phdr *const phdrp =
+			(const struct elf_phdr *) (vsyscall_ehdr + ehdrp->e_phoff);
+		int i;
+		Elf32_Off ofs = 0;
+
+		for (i = 0; i < ehdrp->e_phnum; ++i) {
+			struct elf_phdr phdr = phdrp[i];
+
+			if (phdr.p_type == PT_LOAD) {
+				ofs = phdr.p_offset = offset;
+				offset += phdr.p_filesz;
+			} else {
+				phdr.p_offset += ofs;
+			}
+			phdr.p_paddr = 0; /* match other core phdrs */
+			if (!dump_emit(cprm, &phdr, sizeof(phdr)))
+				return 0;
+		}
+	}
+	return 1;
+}
+
+int elf_core_write_extra_data(struct coredump_params *cprm)
+{
+	if ( vsyscall_ehdr ) {
+		const struct elfhdr *const ehdrp =
+			(struct elfhdr *) vsyscall_ehdr;
+		const struct elf_phdr *const phdrp =
+			(const struct elf_phdr *) (vsyscall_ehdr + ehdrp->e_phoff);
+		int i;
+
+		for (i = 0; i < ehdrp->e_phnum; ++i) {
+			if (phdrp[i].p_type == PT_LOAD) {
+				void *addr = (void *) phdrp[i].p_vaddr;
+				size_t filesz = phdrp[i].p_filesz;
+				if (!dump_emit(cprm, addr, filesz))
+					return 0;
+			}
+		}
+	}
+	return 1;
+}
+
+size_t elf_core_extra_data_size(struct coredump_params *cprm)
+{
+	if ( vsyscall_ehdr ) {
+		const struct elfhdr *const ehdrp =
+			(struct elfhdr *)vsyscall_ehdr;
+		const struct elf_phdr *const phdrp =
+			(const struct elf_phdr *) (vsyscall_ehdr + ehdrp->e_phoff);
+		int i;
+
+		for (i = 0; i < ehdrp->e_phnum; ++i)
+			if (phdrp[i].p_type == PT_LOAD)
+				return (size_t) phdrp[i].p_filesz;
+	}
+	return 0;
+}
diff --git a/arch/x86/um/fault.c b/arch/x86/um/fault.c
new file mode 100644
index 0000000000..84ac7f7b02
--- /dev/null
+++ b/arch/x86/um/fault.c
@@ -0,0 +1,28 @@
+/* 
+ * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+ * Licensed under the GPL
+ */
+
+#include <sysdep/ptrace.h>
+
+/* These two are from asm-um/uaccess.h and linux/module.h, check them. */
+struct exception_table_entry
+{
+	unsigned long insn;
+	unsigned long fixup;
+};
+
+const struct exception_table_entry *search_exception_tables(unsigned long add);
+
+/* Compare this to arch/i386/mm/extable.c:fixup_exception() */
+int arch_fixup(unsigned long address, struct uml_pt_regs *regs)
+{
+	const struct exception_table_entry *fixup;
+
+	fixup = search_exception_tables(address);
+	if (fixup) {
+		UPT_IP(regs) = fixup->fixup;
+		return 1;
+	}
+	return 0;
+}
diff --git a/arch/x86/um/ldt.c b/arch/x86/um/ldt.c
new file mode 100644
index 0000000000..255a44dd41
--- /dev/null
+++ b/arch/x86/um/ldt.c
@@ -0,0 +1,380 @@
+/*
+ * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+ * Licensed under the GPL
+ */
+
+#include <linux/mm.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/syscalls.h>
+#include <linux/uaccess.h>
+#include <asm/unistd.h>
+#include <os.h>
+#include <skas.h>
+#include <sysdep/tls.h>
+
+static inline int modify_ldt (int func, void *ptr, unsigned long bytecount)
+{
+	return syscall(__NR_modify_ldt, func, ptr, bytecount);
+}
+
+static long write_ldt_entry(struct mm_id *mm_idp, int func,
+		     struct user_desc *desc, void **addr, int done)
+{
+	long res;
+	void *stub_addr;
+
+	BUILD_BUG_ON(sizeof(*desc) % sizeof(long));
+
+	res = syscall_stub_data(mm_idp, (unsigned long *)desc,
+				sizeof(*desc) / sizeof(long),
+				addr, &stub_addr);
+	if (!res) {
+		unsigned long args[] = { func,
+					 (unsigned long)stub_addr,
+					 sizeof(*desc),
+					 0, 0, 0 };
+		res = run_syscall_stub(mm_idp, __NR_modify_ldt, args,
+				       0, addr, done);
+	}
+
+	return res;
+}
+
+/*
+ * In skas mode, we hold our own ldt data in UML.
+ * Thus, the code implementing sys_modify_ldt_skas
+ * is very similar to (and mostly stolen from) sys_modify_ldt
+ * for arch/i386/kernel/ldt.c
+ * The routines copied and modified in part are:
+ * - read_ldt
+ * - read_default_ldt
+ * - write_ldt
+ * - sys_modify_ldt_skas
+ */
+
+static int read_ldt(void __user * ptr, unsigned long bytecount)
+{
+	int i, err = 0;
+	unsigned long size;
+	uml_ldt_t *ldt = &current->mm->context.arch.ldt;
+
+	if (!ldt->entry_count)
+		goto out;
+	if (bytecount > LDT_ENTRY_SIZE*LDT_ENTRIES)
+		bytecount = LDT_ENTRY_SIZE*LDT_ENTRIES;
+	err = bytecount;
+
+	mutex_lock(&ldt->lock);
+	if (ldt->entry_count <= LDT_DIRECT_ENTRIES) {
+		size = LDT_ENTRY_SIZE*LDT_DIRECT_ENTRIES;
+		if (size > bytecount)
+			size = bytecount;
+		if (copy_to_user(ptr, ldt->u.entries, size))
+			err = -EFAULT;
+		bytecount -= size;
+		ptr += size;
+	}
+	else {
+		for (i=0; i<ldt->entry_count/LDT_ENTRIES_PER_PAGE && bytecount;
+		     i++) {
+			size = PAGE_SIZE;
+			if (size > bytecount)
+				size = bytecount;
+			if (copy_to_user(ptr, ldt->u.pages[i], size)) {
+				err = -EFAULT;
+				break;
+			}
+			bytecount -= size;
+			ptr += size;
+		}
+	}
+	mutex_unlock(&ldt->lock);
+
+	if (bytecount == 0 || err == -EFAULT)
+		goto out;
+
+	if (clear_user(ptr, bytecount))
+		err = -EFAULT;
+
+out:
+	return err;
+}
+
+static int read_default_ldt(void __user * ptr, unsigned long bytecount)
+{
+	int err;
+
+	if (bytecount > 5*LDT_ENTRY_SIZE)
+		bytecount = 5*LDT_ENTRY_SIZE;
+
+	err = bytecount;
+	/*
+	 * UML doesn't support lcall7 and lcall27.
+	 * So, we don't really have a default ldt, but emulate
+	 * an empty ldt of common host default ldt size.
+	 */
+	if (clear_user(ptr, bytecount))
+		err = -EFAULT;
+
+	return err;
+}
+
+static int write_ldt(void __user * ptr, unsigned long bytecount, int func)
+{
+	uml_ldt_t *ldt = &current->mm->context.arch.ldt;
+	struct mm_id * mm_idp = &current->mm->context.id;
+	int i, err;
+	struct user_desc ldt_info;
+	struct ldt_entry entry0, *ldt_p;
+	void *addr = NULL;
+
+	err = -EINVAL;
+	if (bytecount != sizeof(ldt_info))
+		goto out;
+	err = -EFAULT;
+	if (copy_from_user(&ldt_info, ptr, sizeof(ldt_info)))
+		goto out;
+
+	err = -EINVAL;
+	if (ldt_info.entry_number >= LDT_ENTRIES)
+		goto out;
+	if (ldt_info.contents == 3) {
+		if (func == 1)
+			goto out;
+		if (ldt_info.seg_not_present == 0)
+			goto out;
+	}
+
+	mutex_lock(&ldt->lock);
+
+	err = write_ldt_entry(mm_idp, func, &ldt_info, &addr, 1);
+	if (err)
+		goto out_unlock;
+
+	if (ldt_info.entry_number >= ldt->entry_count &&
+	    ldt_info.entry_number >= LDT_DIRECT_ENTRIES) {
+		for (i=ldt->entry_count/LDT_ENTRIES_PER_PAGE;
+		     i*LDT_ENTRIES_PER_PAGE <= ldt_info.entry_number;
+		     i++) {
+			if (i == 0)
+				memcpy(&entry0, ldt->u.entries,
+				       sizeof(entry0));
+			ldt->u.pages[i] = (struct ldt_entry *)
+				__get_free_page(GFP_KERNEL|__GFP_ZERO);
+			if (!ldt->u.pages[i]) {
+				err = -ENOMEM;
+				/* Undo the change in host */
+				memset(&ldt_info, 0, sizeof(ldt_info));
+				write_ldt_entry(mm_idp, 1, &ldt_info, &addr, 1);
+				goto out_unlock;
+			}
+			if (i == 0) {
+				memcpy(ldt->u.pages[0], &entry0,
+				       sizeof(entry0));
+				memcpy(ldt->u.pages[0]+1, ldt->u.entries+1,
+				       sizeof(entry0)*(LDT_DIRECT_ENTRIES-1));
+			}
+			ldt->entry_count = (i + 1) * LDT_ENTRIES_PER_PAGE;
+		}
+	}
+	if (ldt->entry_count <= ldt_info.entry_number)
+		ldt->entry_count = ldt_info.entry_number + 1;
+
+	if (ldt->entry_count <= LDT_DIRECT_ENTRIES)
+		ldt_p = ldt->u.entries + ldt_info.entry_number;
+	else
+		ldt_p = ldt->u.pages[ldt_info.entry_number/LDT_ENTRIES_PER_PAGE] +
+			ldt_info.entry_number%LDT_ENTRIES_PER_PAGE;
+
+	if (ldt_info.base_addr == 0 && ldt_info.limit == 0 &&
+	   (func == 1 || LDT_empty(&ldt_info))) {
+		ldt_p->a = 0;
+		ldt_p->b = 0;
+	}
+	else{
+		if (func == 1)
+			ldt_info.useable = 0;
+		ldt_p->a = LDT_entry_a(&ldt_info);
+		ldt_p->b = LDT_entry_b(&ldt_info);
+	}
+	err = 0;
+
+out_unlock:
+	mutex_unlock(&ldt->lock);
+out:
+	return err;
+}
+
+static long do_modify_ldt_skas(int func, void __user *ptr,
+			       unsigned long bytecount)
+{
+	int ret = -ENOSYS;
+
+	switch (func) {
+		case 0:
+			ret = read_ldt(ptr, bytecount);
+			break;
+		case 1:
+		case 0x11:
+			ret = write_ldt(ptr, bytecount, func);
+			break;
+		case 2:
+			ret = read_default_ldt(ptr, bytecount);
+			break;
+	}
+	return ret;
+}
+
+static DEFINE_SPINLOCK(host_ldt_lock);
+static short dummy_list[9] = {0, -1};
+static short * host_ldt_entries = NULL;
+
+static void ldt_get_host_info(void)
+{
+	long ret;
+	struct ldt_entry * ldt;
+	short *tmp;
+	int i, size, k, order;
+
+	spin_lock(&host_ldt_lock);
+
+	if (host_ldt_entries != NULL) {
+		spin_unlock(&host_ldt_lock);
+		return;
+	}
+	host_ldt_entries = dummy_list+1;
+
+	spin_unlock(&host_ldt_lock);
+
+	for (i = LDT_PAGES_MAX-1, order=0; i; i>>=1, order++)
+		;
+
+	ldt = (struct ldt_entry *)
+	      __get_free_pages(GFP_KERNEL|__GFP_ZERO, order);
+	if (ldt == NULL) {
+		printk(KERN_ERR "ldt_get_host_info: couldn't allocate buffer "
+		       "for host ldt\n");
+		return;
+	}
+
+	ret = modify_ldt(0, ldt, (1<<order)*PAGE_SIZE);
+	if (ret < 0) {
+		printk(KERN_ERR "ldt_get_host_info: couldn't read host ldt\n");
+		goto out_free;
+	}
+	if (ret == 0) {
+		/* default_ldt is active, simply write an empty entry 0 */
+		host_ldt_entries = dummy_list;
+		goto out_free;
+	}
+
+	for (i=0, size=0; i<ret/LDT_ENTRY_SIZE; i++) {
+		if (ldt[i].a != 0 || ldt[i].b != 0)
+			size++;
+	}
+
+	if (size < ARRAY_SIZE(dummy_list))
+		host_ldt_entries = dummy_list;
+	else {
+		size = (size + 1) * sizeof(dummy_list[0]);
+		tmp = kmalloc(size, GFP_KERNEL);
+		if (tmp == NULL) {
+			printk(KERN_ERR "ldt_get_host_info: couldn't allocate "
+			       "host ldt list\n");
+			goto out_free;
+		}
+		host_ldt_entries = tmp;
+	}
+
+	for (i=0, k=0; i<ret/LDT_ENTRY_SIZE; i++) {
+		if (ldt[i].a != 0 || ldt[i].b != 0)
+			host_ldt_entries[k++] = i;
+	}
+	host_ldt_entries[k] = -1;
+
+out_free:
+	free_pages((unsigned long)ldt, order);
+}
+
+long init_new_ldt(struct mm_context *new_mm, struct mm_context *from_mm)
+{
+	struct user_desc desc;
+	short * num_p;
+	int i;
+	long page, err=0;
+	void *addr = NULL;
+
+
+	mutex_init(&new_mm->arch.ldt.lock);
+
+	if (!from_mm) {
+		memset(&desc, 0, sizeof(desc));
+		/*
+		 * Now we try to retrieve info about the ldt, we
+		 * inherited from the host. All ldt-entries found
+		 * will be reset in the following loop
+		 */
+		ldt_get_host_info();
+		for (num_p=host_ldt_entries; *num_p != -1; num_p++) {
+			desc.entry_number = *num_p;
+			err = write_ldt_entry(&new_mm->id, 1, &desc,
+					      &addr, *(num_p + 1) == -1);
+			if (err)
+				break;
+		}
+		new_mm->arch.ldt.entry_count = 0;
+
+		goto out;
+	}
+
+	/*
+	 * Our local LDT is used to supply the data for
+	 * modify_ldt(READLDT), if PTRACE_LDT isn't available,
+	 * i.e., we have to use the stub for modify_ldt, which
+	 * can't handle the big read buffer of up to 64kB.
+	 */
+	mutex_lock(&from_mm->arch.ldt.lock);
+	if (from_mm->arch.ldt.entry_count <= LDT_DIRECT_ENTRIES)
+		memcpy(new_mm->arch.ldt.u.entries, from_mm->arch.ldt.u.entries,
+		       sizeof(new_mm->arch.ldt.u.entries));
+	else {
+		i = from_mm->arch.ldt.entry_count / LDT_ENTRIES_PER_PAGE;
+		while (i-->0) {
+			page = __get_free_page(GFP_KERNEL|__GFP_ZERO);
+			if (!page) {
+				err = -ENOMEM;
+				break;
+			}
+			new_mm->arch.ldt.u.pages[i] =
+				(struct ldt_entry *) page;
+			memcpy(new_mm->arch.ldt.u.pages[i],
+			       from_mm->arch.ldt.u.pages[i], PAGE_SIZE);
+		}
+	}
+	new_mm->arch.ldt.entry_count = from_mm->arch.ldt.entry_count;
+	mutex_unlock(&from_mm->arch.ldt.lock);
+
+    out:
+	return err;
+}
+
+
+void free_ldt(struct mm_context *mm)
+{
+	int i;
+
+	if (mm->arch.ldt.entry_count > LDT_DIRECT_ENTRIES) {
+		i = mm->arch.ldt.entry_count / LDT_ENTRIES_PER_PAGE;
+		while (i-- > 0)
+			free_page((long) mm->arch.ldt.u.pages[i]);
+	}
+	mm->arch.ldt.entry_count = 0;
+}
+
+SYSCALL_DEFINE3(modify_ldt, int , func , void __user * , ptr ,
+		unsigned long , bytecount)
+{
+	/* See non-um modify_ldt() for why we do this cast */
+	return (unsigned int)do_modify_ldt_skas(func, ptr, bytecount);
+}
diff --git a/arch/x86/um/mem_32.c b/arch/x86/um/mem_32.c
new file mode 100644
index 0000000000..29b2203bc8
--- /dev/null
+++ b/arch/x86/um/mem_32.c
@@ -0,0 +1,50 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2011 Richard Weinberger <richrd@nod.at>
+ */
+
+#include <linux/mm.h>
+#include <asm/elf.h>
+
+static struct vm_area_struct gate_vma;
+
+static int __init gate_vma_init(void)
+{
+	if (!FIXADDR_USER_START)
+		return 0;
+
+	vma_init(&gate_vma, NULL);
+	gate_vma.vm_start = FIXADDR_USER_START;
+	gate_vma.vm_end = FIXADDR_USER_END;
+	vm_flags_init(&gate_vma, VM_READ | VM_MAYREAD | VM_EXEC | VM_MAYEXEC);
+	gate_vma.vm_page_prot = PAGE_READONLY;
+
+	return 0;
+}
+__initcall(gate_vma_init);
+
+struct vm_area_struct *get_gate_vma(struct mm_struct *mm)
+{
+	return FIXADDR_USER_START ? &gate_vma : NULL;
+}
+
+int in_gate_area_no_mm(unsigned long addr)
+{
+	if (!FIXADDR_USER_START)
+		return 0;
+
+	if ((addr >= FIXADDR_USER_START) && (addr < FIXADDR_USER_END))
+		return 1;
+
+	return 0;
+}
+
+int in_gate_area(struct mm_struct *mm, unsigned long addr)
+{
+	struct vm_area_struct *vma = get_gate_vma(mm);
+
+	if (!vma)
+		return 0;
+
+	return (addr >= vma->vm_start) && (addr < vma->vm_end);
+}
diff --git a/arch/x86/um/mem_64.c b/arch/x86/um/mem_64.c
new file mode 100644
index 0000000000..c027e93d10
--- /dev/null
+++ b/arch/x86/um/mem_64.c
@@ -0,0 +1,11 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/mm.h>
+#include <asm/elf.h>
+
+const char *arch_vma_name(struct vm_area_struct *vma)
+{
+	if (vma->vm_mm && vma->vm_start == um_vdso_addr)
+		return "[vdso]";
+
+	return NULL;
+}
diff --git a/arch/x86/um/os-Linux/Makefile b/arch/x86/um/os-Linux/Makefile
new file mode 100644
index 0000000000..ae169125d0
--- /dev/null
+++ b/arch/x86/um/os-Linux/Makefile
@@ -0,0 +1,13 @@
+#
+# Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+# Licensed under the GPL
+#
+
+obj-y = registers.o task_size.o mcontext.o
+
+obj-$(CONFIG_X86_32) += tls.o
+obj-$(CONFIG_64BIT) += prctl.o
+
+USER_OBJS := $(obj-y)
+
+include $(srctree)/arch/um/scripts/Makefile.rules
diff --git a/arch/x86/um/os-Linux/mcontext.c b/arch/x86/um/os-Linux/mcontext.c
new file mode 100644
index 0000000000..49c3744cac
--- /dev/null
+++ b/arch/x86/um/os-Linux/mcontext.c
@@ -0,0 +1,32 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <sys/ucontext.h>
+#define __FRAME_OFFSETS
+#include <asm/ptrace.h>
+#include <sysdep/ptrace.h>
+
+void get_regs_from_mc(struct uml_pt_regs *regs, mcontext_t *mc)
+{
+#ifdef __i386__
+#define COPY2(X,Y) regs->gp[X] = mc->gregs[REG_##Y]
+#define COPY(X) regs->gp[X] = mc->gregs[REG_##X]
+#define COPY_SEG(X) regs->gp[X] = mc->gregs[REG_##X] & 0xffff;
+#define COPY_SEG_CPL3(X) regs->gp[X] = (mc->gregs[REG_##X] & 0xffff) | 3;
+	COPY_SEG(GS); COPY_SEG(FS); COPY_SEG(ES); COPY_SEG(DS);
+	COPY(EDI); COPY(ESI); COPY(EBP);
+	COPY2(UESP, ESP); /* sic */
+	COPY(EBX); COPY(EDX); COPY(ECX); COPY(EAX);
+	COPY(EIP); COPY_SEG_CPL3(CS); COPY(EFL); COPY_SEG_CPL3(SS);
+#else
+#define COPY2(X,Y) regs->gp[X/sizeof(unsigned long)] = mc->gregs[REG_##Y]
+#define COPY(X) regs->gp[X/sizeof(unsigned long)] = mc->gregs[REG_##X]
+	COPY(R8); COPY(R9); COPY(R10); COPY(R11);
+	COPY(R12); COPY(R13); COPY(R14); COPY(R15);
+	COPY(RDI); COPY(RSI); COPY(RBP); COPY(RBX);
+	COPY(RDX); COPY(RAX); COPY(RCX); COPY(RSP);
+	COPY(RIP);
+	COPY2(EFLAGS, EFL);
+	COPY2(CS, CSGSFS);
+	regs->gp[CS / sizeof(unsigned long)] &= 0xffff;
+	regs->gp[CS / sizeof(unsigned long)] |= 3;
+#endif
+}
diff --git a/arch/x86/um/os-Linux/prctl.c b/arch/x86/um/os-Linux/prctl.c
new file mode 100644
index 0000000000..8431e87ac3
--- /dev/null
+++ b/arch/x86/um/os-Linux/prctl.c
@@ -0,0 +1,12 @@
+/*
+ * Copyright (C) 2007 Jeff Dike (jdike@{addtoit.com,linux.intel.com})
+ * Licensed under the GPL
+ */
+
+#include <sys/ptrace.h>
+#include <asm/ptrace.h>
+
+int os_arch_prctl(int pid, int option, unsigned long *arg2)
+{
+	return ptrace(PTRACE_ARCH_PRCTL, pid, (unsigned long) arg2, option);
+}
diff --git a/arch/x86/um/os-Linux/registers.c b/arch/x86/um/os-Linux/registers.c
new file mode 100644
index 0000000000..df8f4b4bf9
--- /dev/null
+++ b/arch/x86/um/os-Linux/registers.c
@@ -0,0 +1,169 @@
+/*
+ * Copyright (C) 2004 PathScale, Inc
+ * Copyright (C) 2004 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+ * Licensed under the GPL
+ */
+
+#include <errno.h>
+#include <stdlib.h>
+#include <sys/ptrace.h>
+#ifdef __i386__
+#include <sys/user.h>
+#endif
+#include <longjmp.h>
+#include <sysdep/ptrace_user.h>
+#include <sys/uio.h>
+#include <asm/sigcontext.h>
+#include <linux/elf.h>
+#include <registers.h>
+
+int have_xstate_support;
+
+int save_i387_registers(int pid, unsigned long *fp_regs)
+{
+	if (ptrace(PTRACE_GETFPREGS, pid, 0, fp_regs) < 0)
+		return -errno;
+	return 0;
+}
+
+int save_fp_registers(int pid, unsigned long *fp_regs)
+{
+#ifdef PTRACE_GETREGSET
+	struct iovec iov;
+
+	if (have_xstate_support) {
+		iov.iov_base = fp_regs;
+		iov.iov_len = FP_SIZE * sizeof(unsigned long);
+		if (ptrace(PTRACE_GETREGSET, pid, NT_X86_XSTATE, &iov) < 0)
+			return -errno;
+		return 0;
+	} else
+#endif
+		return save_i387_registers(pid, fp_regs);
+}
+
+int restore_i387_registers(int pid, unsigned long *fp_regs)
+{
+	if (ptrace(PTRACE_SETFPREGS, pid, 0, fp_regs) < 0)
+		return -errno;
+	return 0;
+}
+
+int restore_fp_registers(int pid, unsigned long *fp_regs)
+{
+#ifdef PTRACE_SETREGSET
+	struct iovec iov;
+	if (have_xstate_support) {
+		iov.iov_base = fp_regs;
+		iov.iov_len = FP_SIZE * sizeof(unsigned long);
+		if (ptrace(PTRACE_SETREGSET, pid, NT_X86_XSTATE, &iov) < 0)
+			return -errno;
+		return 0;
+	} else
+#endif
+		return restore_i387_registers(pid, fp_regs);
+}
+
+#ifdef __i386__
+int have_fpx_regs = 1;
+int save_fpx_registers(int pid, unsigned long *fp_regs)
+{
+	if (ptrace(PTRACE_GETFPXREGS, pid, 0, fp_regs) < 0)
+		return -errno;
+	return 0;
+}
+
+int restore_fpx_registers(int pid, unsigned long *fp_regs)
+{
+	if (ptrace(PTRACE_SETFPXREGS, pid, 0, fp_regs) < 0)
+		return -errno;
+	return 0;
+}
+
+int get_fp_registers(int pid, unsigned long *regs)
+{
+	if (have_fpx_regs)
+		return save_fpx_registers(pid, regs);
+	else
+		return save_fp_registers(pid, regs);
+}
+
+int put_fp_registers(int pid, unsigned long *regs)
+{
+	if (have_fpx_regs)
+		return restore_fpx_registers(pid, regs);
+	else
+		return restore_fp_registers(pid, regs);
+}
+
+void arch_init_registers(int pid)
+{
+	struct user_fpxregs_struct fpx_regs;
+	int err;
+
+	err = ptrace(PTRACE_GETFPXREGS, pid, 0, &fpx_regs);
+	if (!err)
+		return;
+
+	if (errno != EIO)
+		panic("check_ptrace : PTRACE_GETFPXREGS failed, errno = %d",
+		      errno);
+
+	have_fpx_regs = 0;
+}
+#else
+
+int get_fp_registers(int pid, unsigned long *regs)
+{
+	return save_fp_registers(pid, regs);
+}
+
+int put_fp_registers(int pid, unsigned long *regs)
+{
+	return restore_fp_registers(pid, regs);
+}
+
+void arch_init_registers(int pid)
+{
+#ifdef PTRACE_GETREGSET
+	void * fp_regs;
+	struct iovec iov;
+
+	fp_regs = malloc(FP_SIZE * sizeof(unsigned long));
+	if(fp_regs == NULL)
+		return;
+
+	iov.iov_base = fp_regs;
+	iov.iov_len = FP_SIZE * sizeof(unsigned long);
+	if (ptrace(PTRACE_GETREGSET, pid, NT_X86_XSTATE, &iov) == 0)
+		have_xstate_support = 1;
+
+	free(fp_regs);
+#endif
+}
+#endif
+
+unsigned long get_thread_reg(int reg, jmp_buf *buf)
+{
+	switch (reg) {
+#ifdef __i386__
+	case HOST_IP:
+		return buf[0]->__eip;
+	case HOST_SP:
+		return buf[0]->__esp;
+	case HOST_BP:
+		return buf[0]->__ebp;
+#else
+	case HOST_IP:
+		return buf[0]->__rip;
+	case HOST_SP:
+		return buf[0]->__rsp;
+	case HOST_BP:
+		return buf[0]->__rbp;
+#endif
+	default:
+		printk(UM_KERN_ERR "get_thread_regs - unknown register %d\n",
+		       reg);
+		return 0;
+	}
+}
diff --git a/arch/x86/um/os-Linux/task_size.c b/arch/x86/um/os-Linux/task_size.c
new file mode 100644
index 0000000000..1dc9adc20b
--- /dev/null
+++ b/arch/x86/um/os-Linux/task_size.c
@@ -0,0 +1,151 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <stdio.h>
+#include <stdlib.h>
+#include <signal.h>
+#include <sys/mman.h>
+#include <longjmp.h>
+
+#ifdef __i386__
+
+static jmp_buf buf;
+
+static void segfault(int sig)
+{
+	longjmp(buf, 1);
+}
+
+static int page_ok(unsigned long page)
+{
+	unsigned long *address = (unsigned long *) (page << UM_KERN_PAGE_SHIFT);
+	unsigned long n = ~0UL;
+	void *mapped = NULL;
+	int ok = 0;
+
+	/*
+	 * First see if the page is readable.  If it is, it may still
+	 * be a VDSO, so we go on to see if it's writable.  If not
+	 * then try mapping memory there.  If that fails, then we're
+	 * still in the kernel area.  As a sanity check, we'll fail if
+	 * the mmap succeeds, but gives us an address different from
+	 * what we wanted.
+	 */
+	if (setjmp(buf) == 0)
+		n = *address;
+	else {
+		mapped = mmap(address, UM_KERN_PAGE_SIZE,
+			      PROT_READ | PROT_WRITE,
+			      MAP_FIXED | MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+		if (mapped == MAP_FAILED)
+			return 0;
+		if (mapped != address)
+			goto out;
+	}
+
+	/*
+	 * Now, is it writeable?  If so, then we're in user address
+	 * space.  If not, then try mprotecting it and try the write
+	 * again.
+	 */
+	if (setjmp(buf) == 0) {
+		*address = n;
+		ok = 1;
+		goto out;
+	} else if (mprotect(address, UM_KERN_PAGE_SIZE,
+			    PROT_READ | PROT_WRITE) != 0)
+		goto out;
+
+	if (setjmp(buf) == 0) {
+		*address = n;
+		ok = 1;
+	}
+
+ out:
+	if (mapped != NULL)
+		munmap(mapped, UM_KERN_PAGE_SIZE);
+	return ok;
+}
+
+unsigned long os_get_top_address(void)
+{
+	struct sigaction sa, old;
+	unsigned long bottom = 0;
+	/*
+	 * A 32-bit UML on a 64-bit host gets confused about the VDSO at
+	 * 0xffffe000.  It is mapped, is readable, can be reprotected writeable
+	 * and written.  However, exec discovers later that it can't be
+	 * unmapped.  So, just set the highest address to be checked to just
+	 * below it.  This might waste some address space on 4G/4G 32-bit
+	 * hosts, but shouldn't hurt otherwise.
+	 */
+	unsigned long top = 0xffffd000 >> UM_KERN_PAGE_SHIFT;
+	unsigned long test, original;
+
+	printf("Locating the bottom of the address space ... ");
+	fflush(stdout);
+
+	/*
+	 * We're going to be longjmping out of the signal handler, so
+	 * SA_DEFER needs to be set.
+	 */
+	sa.sa_handler = segfault;
+	sigemptyset(&sa.sa_mask);
+	sa.sa_flags = SA_NODEFER;
+	if (sigaction(SIGSEGV, &sa, &old)) {
+		perror("os_get_top_address");
+		exit(1);
+	}
+
+	/* Manually scan the address space, bottom-up, until we find
+	 * the first valid page (or run out of them).
+	 */
+	for (bottom = 0; bottom < top; bottom++) {
+		if (page_ok(bottom))
+			break;
+	}
+
+	/* If we've got this far, we ran out of pages. */
+	if (bottom == top) {
+		fprintf(stderr, "Unable to determine bottom of address "
+			"space.\n");
+		exit(1);
+	}
+
+	printf("0x%lx\n", bottom << UM_KERN_PAGE_SHIFT);
+	printf("Locating the top of the address space ... ");
+	fflush(stdout);
+
+	original = bottom;
+
+	/* This could happen with a 4G/4G split */
+	if (page_ok(top))
+		goto out;
+
+	do {
+		test = bottom + (top - bottom) / 2;
+		if (page_ok(test))
+			bottom = test;
+		else
+			top = test;
+	} while (top - bottom > 1);
+
+out:
+	/* Restore the old SIGSEGV handling */
+	if (sigaction(SIGSEGV, &old, NULL)) {
+		perror("os_get_top_address");
+		exit(1);
+	}
+	top <<= UM_KERN_PAGE_SHIFT;
+	printf("0x%lx\n", top);
+
+	return top;
+}
+
+#else
+
+unsigned long os_get_top_address(void)
+{
+	/* The old value of CONFIG_TOP_ADDR */
+	return 0x7fc0002000;
+}
+
+#endif
diff --git a/arch/x86/um/os-Linux/tls.c b/arch/x86/um/os-Linux/tls.c
new file mode 100644
index 0000000000..3e1b1bf6ac
--- /dev/null
+++ b/arch/x86/um/os-Linux/tls.c
@@ -0,0 +1,68 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <errno.h>
+#include <linux/unistd.h>
+
+#include <sys/ptrace.h>
+#include <sys/syscall.h>
+#include <unistd.h>
+
+#include <sysdep/tls.h>
+
+#ifndef PTRACE_GET_THREAD_AREA
+#define PTRACE_GET_THREAD_AREA 25
+#endif
+
+#ifndef PTRACE_SET_THREAD_AREA
+#define PTRACE_SET_THREAD_AREA 26
+#endif
+
+/* Checks whether host supports TLS, and sets *tls_min according to the value
+ * valid on the host.
+ * i386 host have it == 6; x86_64 host have it == 12, for i386 emulation. */
+void check_host_supports_tls(int *supports_tls, int *tls_min)
+{
+	/* Values for x86 and x86_64.*/
+	int val[] = {GDT_ENTRY_TLS_MIN_I386, GDT_ENTRY_TLS_MIN_X86_64};
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(val); i++) {
+		user_desc_t info;
+		info.entry_number = val[i];
+
+		if (syscall(__NR_get_thread_area, &info) == 0) {
+			*tls_min = val[i];
+			*supports_tls = 1;
+			return;
+		} else {
+			if (errno == EINVAL)
+				continue;
+			else if (errno == ENOSYS)
+				*supports_tls = 0;
+			return;
+		}
+	}
+
+	*supports_tls = 0;
+}
+
+int os_set_thread_area(user_desc_t *info, int pid)
+{
+	int ret;
+
+	ret = ptrace(PTRACE_SET_THREAD_AREA, pid, info->entry_number,
+		     (unsigned long) info);
+	if (ret < 0)
+		ret = -errno;
+	return ret;
+}
+
+int os_get_thread_area(user_desc_t *info, int pid)
+{
+	int ret;
+
+	ret = ptrace(PTRACE_GET_THREAD_AREA, pid, info->entry_number,
+		     (unsigned long) info);
+	if (ret < 0)
+		ret = -errno;
+	return ret;
+}
diff --git a/arch/x86/um/ptrace_32.c b/arch/x86/um/ptrace_32.c
new file mode 100644
index 0000000000..0bc4b73a9c
--- /dev/null
+++ b/arch/x86/um/ptrace_32.c
@@ -0,0 +1,278 @@
+/*
+ * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+ * Licensed under the GPL
+ */
+
+#include <linux/mm.h>
+#include <linux/sched.h>
+#include <linux/uaccess.h>
+#include <asm/ptrace-abi.h>
+#include <registers.h>
+#include <skas.h>
+
+extern int arch_switch_tls(struct task_struct *to);
+
+void arch_switch_to(struct task_struct *to)
+{
+	int err = arch_switch_tls(to);
+	if (!err)
+		return;
+
+	if (err != -EINVAL)
+		printk(KERN_WARNING "arch_switch_tls failed, errno %d, "
+		       "not EINVAL\n", -err);
+	else
+		printk(KERN_WARNING "arch_switch_tls failed, errno = EINVAL\n");
+}
+
+int is_syscall(unsigned long addr)
+{
+	unsigned short instr;
+	int n;
+
+	n = copy_from_user(&instr, (void __user *) addr, sizeof(instr));
+	if (n) {
+		/* access_process_vm() grants access to vsyscall and stub,
+		 * while copy_from_user doesn't. Maybe access_process_vm is
+		 * slow, but that doesn't matter, since it will be called only
+		 * in case of singlestepping, if copy_from_user failed.
+		 */
+		n = access_process_vm(current, addr, &instr, sizeof(instr),
+				FOLL_FORCE);
+		if (n != sizeof(instr)) {
+			printk(KERN_ERR "is_syscall : failed to read "
+			       "instruction from 0x%lx\n", addr);
+			return 1;
+		}
+	}
+	/* int 0x80 or sysenter */
+	return (instr == 0x80cd) || (instr == 0x340f);
+}
+
+/* determines which flags the user has access to. */
+/* 1 = access 0 = no access */
+#define FLAG_MASK 0x00044dd5
+
+static const int reg_offsets[] = {
+	[EBX] = HOST_BX,
+	[ECX] = HOST_CX,
+	[EDX] = HOST_DX,
+	[ESI] = HOST_SI,
+	[EDI] = HOST_DI,
+	[EBP] = HOST_BP,
+	[EAX] = HOST_AX,
+	[DS] = HOST_DS,
+	[ES] = HOST_ES,
+	[FS] = HOST_FS,
+	[GS] = HOST_GS,
+	[EIP] = HOST_IP,
+	[CS] = HOST_CS,
+	[EFL] = HOST_EFLAGS,
+	[UESP] = HOST_SP,
+	[SS] = HOST_SS,
+	[ORIG_EAX] = HOST_ORIG_AX,
+};
+
+int putreg(struct task_struct *child, int regno, unsigned long value)
+{
+	regno >>= 2;
+	switch (regno) {
+	case EBX:
+	case ECX:
+	case EDX:
+	case ESI:
+	case EDI:
+	case EBP:
+	case EAX:
+	case EIP:
+	case UESP:
+		break;
+	case ORIG_EAX:
+		/* Update the syscall number. */
+		UPT_SYSCALL_NR(&child->thread.regs.regs) = value;
+		break;
+	case FS:
+		if (value && (value & 3) != 3)
+			return -EIO;
+		break;
+	case GS:
+		if (value && (value & 3) != 3)
+			return -EIO;
+		break;
+	case DS:
+	case ES:
+		if (value && (value & 3) != 3)
+			return -EIO;
+		value &= 0xffff;
+		break;
+	case SS:
+	case CS:
+		if ((value & 3) != 3)
+			return -EIO;
+		value &= 0xffff;
+		break;
+	case EFL:
+		value &= FLAG_MASK;
+		child->thread.regs.regs.gp[HOST_EFLAGS] |= value;
+		return 0;
+	default :
+		panic("Bad register in putreg() : %d\n", regno);
+	}
+	child->thread.regs.regs.gp[reg_offsets[regno]] = value;
+	return 0;
+}
+
+int poke_user(struct task_struct *child, long addr, long data)
+{
+	if ((addr & 3) || addr < 0)
+		return -EIO;
+
+	if (addr < MAX_REG_OFFSET)
+		return putreg(child, addr, data);
+	else if ((addr >= offsetof(struct user, u_debugreg[0])) &&
+		 (addr <= offsetof(struct user, u_debugreg[7]))) {
+		addr -= offsetof(struct user, u_debugreg[0]);
+		addr = addr >> 2;
+		if ((addr == 4) || (addr == 5))
+			return -EIO;
+		child->thread.arch.debugregs[addr] = data;
+		return 0;
+	}
+	return -EIO;
+}
+
+unsigned long getreg(struct task_struct *child, int regno)
+{
+	unsigned long mask = ~0UL;
+
+	regno >>= 2;
+	switch (regno) {
+	case FS:
+	case GS:
+	case DS:
+	case ES:
+	case SS:
+	case CS:
+		mask = 0xffff;
+		break;
+	case EIP:
+	case UESP:
+	case EAX:
+	case EBX:
+	case ECX:
+	case EDX:
+	case ESI:
+	case EDI:
+	case EBP:
+	case EFL:
+	case ORIG_EAX:
+		break;
+	default:
+		panic("Bad register in getreg() : %d\n", regno);
+	}
+	return mask & child->thread.regs.regs.gp[reg_offsets[regno]];
+}
+
+/* read the word at location addr in the USER area. */
+int peek_user(struct task_struct *child, long addr, long data)
+{
+	unsigned long tmp;
+
+	if ((addr & 3) || addr < 0)
+		return -EIO;
+
+	tmp = 0;  /* Default return condition */
+	if (addr < MAX_REG_OFFSET) {
+		tmp = getreg(child, addr);
+	}
+	else if ((addr >= offsetof(struct user, u_debugreg[0])) &&
+		 (addr <= offsetof(struct user, u_debugreg[7]))) {
+		addr -= offsetof(struct user, u_debugreg[0]);
+		addr = addr >> 2;
+		tmp = child->thread.arch.debugregs[addr];
+	}
+	return put_user(tmp, (unsigned long __user *) data);
+}
+
+static int get_fpregs(struct user_i387_struct __user *buf, struct task_struct *child)
+{
+	int err, n, cpu = task_cpu(child);
+	struct user_i387_struct fpregs;
+
+	err = save_i387_registers(userspace_pid[cpu],
+				  (unsigned long *) &fpregs);
+	if (err)
+		return err;
+
+	n = copy_to_user(buf, &fpregs, sizeof(fpregs));
+	if(n > 0)
+		return -EFAULT;
+
+	return n;
+}
+
+static int set_fpregs(struct user_i387_struct __user *buf, struct task_struct *child)
+{
+	int n, cpu = task_cpu(child);
+	struct user_i387_struct fpregs;
+
+	n = copy_from_user(&fpregs, buf, sizeof(fpregs));
+	if (n > 0)
+		return -EFAULT;
+
+	return restore_i387_registers(userspace_pid[cpu],
+				    (unsigned long *) &fpregs);
+}
+
+static int get_fpxregs(struct user_fxsr_struct __user *buf, struct task_struct *child)
+{
+	int err, n, cpu = task_cpu(child);
+	struct user_fxsr_struct fpregs;
+
+	err = save_fpx_registers(userspace_pid[cpu], (unsigned long *) &fpregs);
+	if (err)
+		return err;
+
+	n = copy_to_user(buf, &fpregs, sizeof(fpregs));
+	if(n > 0)
+		return -EFAULT;
+
+	return n;
+}
+
+static int set_fpxregs(struct user_fxsr_struct __user *buf, struct task_struct *child)
+{
+	int n, cpu = task_cpu(child);
+	struct user_fxsr_struct fpregs;
+
+	n = copy_from_user(&fpregs, buf, sizeof(fpregs));
+	if (n > 0)
+		return -EFAULT;
+
+	return restore_fpx_registers(userspace_pid[cpu],
+				     (unsigned long *) &fpregs);
+}
+
+long subarch_ptrace(struct task_struct *child, long request,
+		    unsigned long addr, unsigned long data)
+{
+	int ret = -EIO;
+	void __user *datap = (void __user *) data;
+	switch (request) {
+	case PTRACE_GETFPREGS: /* Get the child FPU state. */
+		ret = get_fpregs(datap, child);
+		break;
+	case PTRACE_SETFPREGS: /* Set the child FPU state. */
+		ret = set_fpregs(datap, child);
+		break;
+	case PTRACE_GETFPXREGS: /* Get the child FPU state. */
+		ret = get_fpxregs(datap, child);
+		break;
+	case PTRACE_SETFPXREGS: /* Set the child FPU state. */
+		ret = set_fpxregs(datap, child);
+		break;
+	default:
+		ret = -EIO;
+	}
+	return ret;
+}
diff --git a/arch/x86/um/ptrace_64.c b/arch/x86/um/ptrace_64.c
new file mode 100644
index 0000000000..289d0159b0
--- /dev/null
+++ b/arch/x86/um/ptrace_64.c
@@ -0,0 +1,267 @@
+/*
+ * Copyright 2003 PathScale, Inc.
+ * Copyright (C) 2003 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+ *
+ * Licensed under the GPL
+ */
+
+#include <linux/mm.h>
+#include <linux/sched.h>
+#include <linux/errno.h>
+#define __FRAME_OFFSETS
+#include <asm/ptrace.h>
+#include <linux/uaccess.h>
+#include <registers.h>
+#include <asm/ptrace-abi.h>
+
+/*
+ * determines which flags the user has access to.
+ * 1 = access 0 = no access
+ */
+#define FLAG_MASK 0x44dd5UL
+
+static const int reg_offsets[] =
+{
+	[R8 >> 3] = HOST_R8,
+	[R9 >> 3] = HOST_R9,
+	[R10 >> 3] = HOST_R10,
+	[R11 >> 3] = HOST_R11,
+	[R12 >> 3] = HOST_R12,
+	[R13 >> 3] = HOST_R13,
+	[R14 >> 3] = HOST_R14,
+	[R15 >> 3] = HOST_R15,
+	[RIP >> 3] = HOST_IP,
+	[RSP >> 3] = HOST_SP,
+	[RAX >> 3] = HOST_AX,
+	[RBX >> 3] = HOST_BX,
+	[RCX >> 3] = HOST_CX,
+	[RDX >> 3] = HOST_DX,
+	[RSI >> 3] = HOST_SI,
+	[RDI >> 3] = HOST_DI,
+	[RBP >> 3] = HOST_BP,
+	[CS >> 3] = HOST_CS,
+	[SS >> 3] = HOST_SS,
+	[FS_BASE >> 3] = HOST_FS_BASE,
+	[GS_BASE >> 3] = HOST_GS_BASE,
+	[DS >> 3] = HOST_DS,
+	[ES >> 3] = HOST_ES,
+	[FS >> 3] = HOST_FS,
+	[GS >> 3] = HOST_GS,
+	[EFLAGS >> 3] = HOST_EFLAGS,
+	[ORIG_RAX >> 3] = HOST_ORIG_AX,
+};
+
+int putreg(struct task_struct *child, int regno, unsigned long value)
+{
+	switch (regno) {
+	case R8:
+	case R9:
+	case R10:
+	case R11:
+	case R12:
+	case R13:
+	case R14:
+	case R15:
+	case RIP:
+	case RSP:
+	case RAX:
+	case RBX:
+	case RCX:
+	case RDX:
+	case RSI:
+	case RDI:
+	case RBP:
+		break;
+
+	case ORIG_RAX:
+		/* Update the syscall number. */
+		UPT_SYSCALL_NR(&child->thread.regs.regs) = value;
+		break;
+
+	case FS:
+	case GS:
+	case DS:
+	case ES:
+	case SS:
+	case CS:
+		if (value && (value & 3) != 3)
+			return -EIO;
+		value &= 0xffff;
+		break;
+
+	case FS_BASE:
+	case GS_BASE:
+		if (!((value >> 48) == 0 || (value >> 48) == 0xffff))
+			return -EIO;
+		break;
+
+	case EFLAGS:
+		value &= FLAG_MASK;
+		child->thread.regs.regs.gp[HOST_EFLAGS] |= value;
+		return 0;
+
+	default:
+		panic("Bad register in putreg(): %d\n", regno);
+	}
+
+	child->thread.regs.regs.gp[reg_offsets[regno >> 3]] = value;
+	return 0;
+}
+
+int poke_user(struct task_struct *child, long addr, long data)
+{
+	if ((addr & 3) || addr < 0)
+		return -EIO;
+
+	if (addr < MAX_REG_OFFSET)
+		return putreg(child, addr, data);
+	else if ((addr >= offsetof(struct user, u_debugreg[0])) &&
+		(addr <= offsetof(struct user, u_debugreg[7]))) {
+		addr -= offsetof(struct user, u_debugreg[0]);
+		addr = addr >> 3;
+		if ((addr == 4) || (addr == 5))
+			return -EIO;
+		child->thread.arch.debugregs[addr] = data;
+		return 0;
+	}
+	return -EIO;
+}
+
+unsigned long getreg(struct task_struct *child, int regno)
+{
+	unsigned long mask = ~0UL;
+
+	switch (regno) {
+	case R8:
+	case R9:
+	case R10:
+	case R11:
+	case R12:
+	case R13:
+	case R14:
+	case R15:
+	case RIP:
+	case RSP:
+	case RAX:
+	case RBX:
+	case RCX:
+	case RDX:
+	case RSI:
+	case RDI:
+	case RBP:
+	case ORIG_RAX:
+	case EFLAGS:
+	case FS_BASE:
+	case GS_BASE:
+		break;
+	case FS:
+	case GS:
+	case DS:
+	case ES:
+	case SS:
+	case CS:
+		mask = 0xffff;
+		break;
+	default:
+		panic("Bad register in getreg: %d\n", regno);
+	}
+	return mask & child->thread.regs.regs.gp[reg_offsets[regno >> 3]];
+}
+
+int peek_user(struct task_struct *child, long addr, long data)
+{
+	/* read the word at location addr in the USER area. */
+	unsigned long tmp;
+
+	if ((addr & 3) || addr < 0)
+		return -EIO;
+
+	tmp = 0;  /* Default return condition */
+	if (addr < MAX_REG_OFFSET)
+		tmp = getreg(child, addr);
+	else if ((addr >= offsetof(struct user, u_debugreg[0])) &&
+		(addr <= offsetof(struct user, u_debugreg[7]))) {
+		addr -= offsetof(struct user, u_debugreg[0]);
+		addr = addr >> 2;
+		tmp = child->thread.arch.debugregs[addr];
+	}
+	return put_user(tmp, (unsigned long *) data);
+}
+
+/* XXX Mostly copied from sys-i386 */
+int is_syscall(unsigned long addr)
+{
+	unsigned short instr;
+	int n;
+
+	n = copy_from_user(&instr, (void __user *) addr, sizeof(instr));
+	if (n) {
+		/*
+		 * access_process_vm() grants access to vsyscall and stub,
+		 * while copy_from_user doesn't. Maybe access_process_vm is
+		 * slow, but that doesn't matter, since it will be called only
+		 * in case of singlestepping, if copy_from_user failed.
+		 */
+		n = access_process_vm(current, addr, &instr, sizeof(instr),
+				FOLL_FORCE);
+		if (n != sizeof(instr)) {
+			printk("is_syscall : failed to read instruction from "
+			       "0x%lx\n", addr);
+			return 1;
+		}
+	}
+	/* sysenter */
+	return instr == 0x050f;
+}
+
+static int get_fpregs(struct user_i387_struct __user *buf, struct task_struct *child)
+{
+	int err, n, cpu = ((struct thread_info *) child->stack)->cpu;
+	struct user_i387_struct fpregs;
+
+	err = save_i387_registers(userspace_pid[cpu],
+				  (unsigned long *) &fpregs);
+	if (err)
+		return err;
+
+	n = copy_to_user(buf, &fpregs, sizeof(fpregs));
+	if (n > 0)
+		return -EFAULT;
+
+	return n;
+}
+
+static int set_fpregs(struct user_i387_struct __user *buf, struct task_struct *child)
+{
+	int n, cpu = ((struct thread_info *) child->stack)->cpu;
+	struct user_i387_struct fpregs;
+
+	n = copy_from_user(&fpregs, buf, sizeof(fpregs));
+	if (n > 0)
+		return -EFAULT;
+
+	return restore_i387_registers(userspace_pid[cpu],
+				      (unsigned long *) &fpregs);
+}
+
+long subarch_ptrace(struct task_struct *child, long request,
+		    unsigned long addr, unsigned long data)
+{
+	int ret = -EIO;
+	void __user *datap = (void __user *) data;
+
+	switch (request) {
+	case PTRACE_GETFPREGS: /* Get the child FPU state. */
+		ret = get_fpregs(datap, child);
+		break;
+	case PTRACE_SETFPREGS: /* Set the child FPU state. */
+		ret = set_fpregs(datap, child);
+		break;
+	case PTRACE_ARCH_PRCTL:
+		/* XXX Calls ptrace on the host - needs some SMP thinking */
+		ret = arch_prctl(child, data, (void __user *) addr);
+		break;
+	}
+
+	return ret;
+}
diff --git a/arch/x86/um/ptrace_user.c b/arch/x86/um/ptrace_user.c
new file mode 100644
index 0000000000..617885b189
--- /dev/null
+++ b/arch/x86/um/ptrace_user.c
@@ -0,0 +1,21 @@
+/*
+ * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+ * Licensed under the GPL
+ */
+
+#include <errno.h>
+#include <ptrace_user.h>
+
+int ptrace_getregs(long pid, unsigned long *regs_out)
+{
+	if (ptrace(PTRACE_GETREGS, pid, 0, regs_out) < 0)
+		return -errno;
+	return 0;
+}
+
+int ptrace_setregs(long pid, unsigned long *regs)
+{
+	if (ptrace(PTRACE_SETREGS, pid, 0, regs) < 0)
+		return -errno;
+	return 0;
+}
diff --git a/arch/x86/um/setjmp_32.S b/arch/x86/um/setjmp_32.S
new file mode 100644
index 0000000000..2d991ddbcc
--- /dev/null
+++ b/arch/x86/um/setjmp_32.S
@@ -0,0 +1,59 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#
+# arch/i386/setjmp.S
+#
+# setjmp/longjmp for the i386 architecture
+#
+
+#
+# The jmp_buf is assumed to contain the following, in order:
+#	%ebx
+#	%esp
+#	%ebp
+#	%esi
+#	%edi
+#	<return address>
+#
+
+	.text
+	.align 4
+	.globl kernel_setjmp
+	.type kernel_setjmp, @function
+kernel_setjmp:
+#ifdef _REGPARM
+	movl %eax,%edx
+#else
+	movl 4(%esp),%edx
+#endif
+	popl %ecx			# Return address, and adjust the stack
+	xorl %eax,%eax			# Return value
+	movl %ebx,(%edx)
+	movl %esp,4(%edx)		# Post-return %esp!
+	pushl %ecx			# Make the call/return stack happy
+	movl %ebp,8(%edx)
+	movl %esi,12(%edx)
+	movl %edi,16(%edx)
+	movl %ecx,20(%edx)		# Return address
+	RET
+
+	.size kernel_setjmp,.-kernel_setjmp
+
+	.text
+	.align 4
+	.globl kernel_longjmp
+	.type kernel_longjmp, @function
+kernel_longjmp:
+#ifdef _REGPARM
+	xchgl %eax,%edx
+#else
+	movl 4(%esp),%edx		# jmp_ptr address
+	movl 8(%esp),%eax		# Return value
+#endif
+	movl (%edx),%ebx
+	movl 4(%edx),%esp
+	movl 8(%edx),%ebp
+	movl 12(%edx),%esi
+	movl 16(%edx),%edi
+	jmp *20(%edx)
+
+	.size kernel_longjmp,.-kernel_longjmp
diff --git a/arch/x86/um/setjmp_64.S b/arch/x86/um/setjmp_64.S
new file mode 100644
index 0000000000..b46acb6a8e
--- /dev/null
+++ b/arch/x86/um/setjmp_64.S
@@ -0,0 +1,55 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#
+# arch/x86_64/setjmp.S
+#
+# setjmp/longjmp for the x86-64 architecture
+#
+
+#
+# The jmp_buf is assumed to contain the following, in order:
+#	%rbx
+#	%rsp (post-return)
+#	%rbp
+#	%r12
+#	%r13
+#	%r14
+#	%r15
+#	<return address>
+#
+
+	.text
+	.align 4
+	.globl kernel_setjmp
+	.type kernel_setjmp, @function
+kernel_setjmp:
+	pop  %rsi			# Return address, and adjust the stack
+	xorl %eax,%eax			# Return value
+	movq %rbx,(%rdi)
+	movq %rsp,8(%rdi)		# Post-return %rsp!
+	push %rsi			# Make the call/return stack happy
+	movq %rbp,16(%rdi)
+	movq %r12,24(%rdi)
+	movq %r13,32(%rdi)
+	movq %r14,40(%rdi)
+	movq %r15,48(%rdi)
+	movq %rsi,56(%rdi)		# Return address
+	RET
+
+	.size kernel_setjmp,.-kernel_setjmp
+
+	.text
+	.align 4
+	.globl kernel_longjmp
+	.type kernel_longjmp, @function
+kernel_longjmp:
+	movl %esi,%eax			# Return value (int)
+	movq (%rdi),%rbx
+	movq 8(%rdi),%rsp
+	movq 16(%rdi),%rbp
+	movq 24(%rdi),%r12
+	movq 32(%rdi),%r13
+	movq 40(%rdi),%r14
+	movq 48(%rdi),%r15
+	jmp *56(%rdi)
+
+	.size kernel_longjmp,.-kernel_longjmp
diff --git a/arch/x86/um/shared/sysdep/archsetjmp.h b/arch/x86/um/shared/sysdep/archsetjmp.h
new file mode 100644
index 0000000000..166cedbab9
--- /dev/null
+++ b/arch/x86/um/shared/sysdep/archsetjmp.h
@@ -0,0 +1,6 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifdef __i386__
+#include "archsetjmp_32.h"
+#else
+#include "archsetjmp_64.h"
+#endif
diff --git a/arch/x86/um/shared/sysdep/archsetjmp_32.h b/arch/x86/um/shared/sysdep/archsetjmp_32.h
new file mode 100644
index 0000000000..fb08f25764
--- /dev/null
+++ b/arch/x86/um/shared/sysdep/archsetjmp_32.h
@@ -0,0 +1,23 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * arch/um/include/sysdep-i386/archsetjmp.h
+ */
+
+#ifndef _KLIBC_ARCHSETJMP_H
+#define _KLIBC_ARCHSETJMP_H
+
+struct __jmp_buf {
+	unsigned int __ebx;
+	unsigned int __esp;
+	unsigned int __ebp;
+	unsigned int __esi;
+	unsigned int __edi;
+	unsigned int __eip;
+};
+
+typedef struct __jmp_buf jmp_buf[1];
+
+#define JB_IP __eip
+#define JB_SP __esp
+
+#endif				/* _SETJMP_H */
diff --git a/arch/x86/um/shared/sysdep/archsetjmp_64.h b/arch/x86/um/shared/sysdep/archsetjmp_64.h
new file mode 100644
index 0000000000..9b499e457b
--- /dev/null
+++ b/arch/x86/um/shared/sysdep/archsetjmp_64.h
@@ -0,0 +1,25 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * arch/um/include/sysdep-x86_64/archsetjmp.h
+ */
+
+#ifndef _KLIBC_ARCHSETJMP_H
+#define _KLIBC_ARCHSETJMP_H
+
+struct __jmp_buf {
+	unsigned long __rbx;
+	unsigned long __rsp;
+	unsigned long __rbp;
+	unsigned long __r12;
+	unsigned long __r13;
+	unsigned long __r14;
+	unsigned long __r15;
+	unsigned long __rip;
+};
+
+typedef struct __jmp_buf jmp_buf[1];
+
+#define JB_IP __rip
+#define JB_SP __rsp
+
+#endif				/* _SETJMP_H */
diff --git a/arch/x86/um/shared/sysdep/faultinfo.h b/arch/x86/um/shared/sysdep/faultinfo.h
new file mode 100644
index 0000000000..4390803e07
--- /dev/null
+++ b/arch/x86/um/shared/sysdep/faultinfo.h
@@ -0,0 +1,6 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifdef __i386__
+#include "faultinfo_32.h"
+#else
+#include "faultinfo_64.h"
+#endif
diff --git a/arch/x86/um/shared/sysdep/faultinfo_32.h b/arch/x86/um/shared/sysdep/faultinfo_32.h
new file mode 100644
index 0000000000..b6f2437ec2
--- /dev/null
+++ b/arch/x86/um/shared/sysdep/faultinfo_32.h
@@ -0,0 +1,32 @@
+/*
+ * Copyright (C) 2004 Fujitsu Siemens Computers GmbH
+ * Author: Bodo Stroesser <bstroesser@fujitsu-siemens.com>
+ * Licensed under the GPL
+ */
+
+#ifndef __FAULTINFO_I386_H
+#define __FAULTINFO_I386_H
+
+/* this structure contains the full arch-specific faultinfo
+ * from the traps.
+ * On i386, ptrace_faultinfo unfortunately doesn't provide
+ * all the info, since trap_no is missing.
+ * All common elements are defined at the same position in
+ * both structures, thus making it easy to copy the
+ * contents without knowledge about the structure elements.
+ */
+struct faultinfo {
+        int error_code; /* in ptrace_faultinfo misleadingly called is_write */
+        unsigned long cr2; /* in ptrace_faultinfo called addr */
+        int trap_no; /* missing in ptrace_faultinfo */
+};
+
+#define FAULT_WRITE(fi) ((fi).error_code & 2)
+#define FAULT_ADDRESS(fi) ((fi).cr2)
+
+/* This is Page Fault */
+#define SEGV_IS_FIXABLE(fi)	((fi)->trap_no == 14)
+
+#define PTRACE_FULL_FAULTINFO 0
+
+#endif
diff --git a/arch/x86/um/shared/sysdep/faultinfo_64.h b/arch/x86/um/shared/sysdep/faultinfo_64.h
new file mode 100644
index 0000000000..ee88f88974
--- /dev/null
+++ b/arch/x86/um/shared/sysdep/faultinfo_64.h
@@ -0,0 +1,32 @@
+/*
+ * Copyright (C) 2004 Fujitsu Siemens Computers GmbH
+ * Author: Bodo Stroesser <bstroesser@fujitsu-siemens.com>
+ * Licensed under the GPL
+ */
+
+#ifndef __FAULTINFO_X86_64_H
+#define __FAULTINFO_X86_64_H
+
+/* this structure contains the full arch-specific faultinfo
+ * from the traps.
+ * On i386, ptrace_faultinfo unfortunately doesn't provide
+ * all the info, since trap_no is missing.
+ * All common elements are defined at the same position in
+ * both structures, thus making it easy to copy the
+ * contents without knowledge about the structure elements.
+ */
+struct faultinfo {
+        int error_code; /* in ptrace_faultinfo misleadingly called is_write */
+        unsigned long cr2; /* in ptrace_faultinfo called addr */
+        int trap_no; /* missing in ptrace_faultinfo */
+};
+
+#define FAULT_WRITE(fi) ((fi).error_code & 2)
+#define FAULT_ADDRESS(fi) ((fi).cr2)
+
+/* This is Page Fault */
+#define SEGV_IS_FIXABLE(fi)	((fi)->trap_no == 14)
+
+#define PTRACE_FULL_FAULTINFO 1
+
+#endif
diff --git a/arch/x86/um/shared/sysdep/kernel-offsets.h b/arch/x86/um/shared/sysdep/kernel-offsets.h
new file mode 100644
index 0000000000..a004bffb7b
--- /dev/null
+++ b/arch/x86/um/shared/sysdep/kernel-offsets.h
@@ -0,0 +1,12 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#include <linux/stddef.h>
+#include <linux/sched.h>
+#include <linux/elf.h>
+#include <linux/crypto.h>
+#include <linux/kbuild.h>
+#include <asm/mman.h>
+
+void foo(void)
+{
+#include <common-offsets.h>
+}
diff --git a/arch/x86/um/shared/sysdep/mcontext.h b/arch/x86/um/shared/sysdep/mcontext.h
new file mode 100644
index 0000000000..b724c54da3
--- /dev/null
+++ b/arch/x86/um/shared/sysdep/mcontext.h
@@ -0,0 +1,31 @@
+/* 
+ * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+ * Licensed under the GPL
+ */
+
+#ifndef __SYS_SIGCONTEXT_X86_H
+#define __SYS_SIGCONTEXT_X86_H
+
+extern void get_regs_from_mc(struct uml_pt_regs *, mcontext_t *);
+
+#ifdef __i386__
+
+#define GET_FAULTINFO_FROM_MC(fi, mc) \
+	{ \
+		(fi).cr2 = (mc)->cr2; \
+		(fi).error_code = (mc)->gregs[REG_ERR]; \
+		(fi).trap_no = (mc)->gregs[REG_TRAPNO]; \
+	}
+
+#else
+
+#define GET_FAULTINFO_FROM_MC(fi, mc) \
+	{ \
+		(fi).cr2 = (mc)->gregs[REG_CR2]; \
+		(fi).error_code = (mc)->gregs[REG_ERR]; \
+		(fi).trap_no = (mc)->gregs[REG_TRAPNO]; \
+	}
+
+#endif
+
+#endif
diff --git a/arch/x86/um/shared/sysdep/ptrace.h b/arch/x86/um/shared/sysdep/ptrace.h
new file mode 100644
index 0000000000..6ca4ecabc5
--- /dev/null
+++ b/arch/x86/um/shared/sysdep/ptrace.h
@@ -0,0 +1,75 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __SYSDEP_X86_PTRACE_H
+#define __SYSDEP_X86_PTRACE_H
+
+#include <generated/user_constants.h>
+#include <sysdep/faultinfo.h>
+
+#define MAX_REG_OFFSET (UM_FRAME_SIZE)
+#define MAX_REG_NR ((MAX_REG_OFFSET) / sizeof(unsigned long))
+
+#define REGS_IP(r) ((r)[HOST_IP])
+#define REGS_SP(r) ((r)[HOST_SP])
+#define REGS_EFLAGS(r) ((r)[HOST_EFLAGS])
+#define REGS_AX(r) ((r)[HOST_AX])
+#define REGS_BX(r) ((r)[HOST_BX])
+#define REGS_CX(r) ((r)[HOST_CX])
+#define REGS_DX(r) ((r)[HOST_DX])
+#define REGS_SI(r) ((r)[HOST_SI])
+#define REGS_DI(r) ((r)[HOST_DI])
+#define REGS_BP(r) ((r)[HOST_BP])
+#define REGS_CS(r) ((r)[HOST_CS])
+#define REGS_SS(r) ((r)[HOST_SS])
+#define REGS_DS(r) ((r)[HOST_DS])
+#define REGS_ES(r) ((r)[HOST_ES])
+
+#define UPT_IP(r) REGS_IP((r)->gp)
+#define UPT_SP(r) REGS_SP((r)->gp)
+#define UPT_EFLAGS(r) REGS_EFLAGS((r)->gp)
+#define UPT_AX(r) REGS_AX((r)->gp)
+#define UPT_BX(r) REGS_BX((r)->gp)
+#define UPT_CX(r) REGS_CX((r)->gp)
+#define UPT_DX(r) REGS_DX((r)->gp)
+#define UPT_SI(r) REGS_SI((r)->gp)
+#define UPT_DI(r) REGS_DI((r)->gp)
+#define UPT_BP(r) REGS_BP((r)->gp)
+#define UPT_CS(r) REGS_CS((r)->gp)
+#define UPT_SS(r) REGS_SS((r)->gp)
+#define UPT_DS(r) REGS_DS((r)->gp)
+#define UPT_ES(r) REGS_ES((r)->gp)
+
+#ifdef __i386__
+#include "ptrace_32.h"
+#else
+#include "ptrace_64.h"
+#endif
+
+struct syscall_args {
+	unsigned long args[6];
+};
+
+#define SYSCALL_ARGS(r) ((struct syscall_args) \
+			 { .args = { UPT_SYSCALL_ARG1(r),	 \
+				     UPT_SYSCALL_ARG2(r),	 \
+				     UPT_SYSCALL_ARG3(r),	 \
+				     UPT_SYSCALL_ARG4(r),	 \
+				     UPT_SYSCALL_ARG5(r),	 \
+				     UPT_SYSCALL_ARG6(r) } } )
+
+struct uml_pt_regs {
+	unsigned long gp[MAX_REG_NR];
+	unsigned long fp[MAX_FP_NR];
+	struct faultinfo faultinfo;
+	long syscall;
+	int is_user;
+};
+
+#define EMPTY_UML_PT_REGS { }
+
+#define UPT_SYSCALL_NR(r) ((r)->syscall)
+#define UPT_FAULTINFO(r) (&(r)->faultinfo)
+#define UPT_IS_USER(r) ((r)->is_user)
+
+extern int user_context(unsigned long sp);
+
+#endif /* __SYSDEP_X86_PTRACE_H */
diff --git a/arch/x86/um/shared/sysdep/ptrace_32.h b/arch/x86/um/shared/sysdep/ptrace_32.h
new file mode 100644
index 0000000000..db8478a83a
--- /dev/null
+++ b/arch/x86/um/shared/sysdep/ptrace_32.h
@@ -0,0 +1,24 @@
+/*
+ * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+ * Licensed under the GPL
+ */
+
+#ifndef __SYSDEP_I386_PTRACE_H
+#define __SYSDEP_I386_PTRACE_H
+
+#define MAX_FP_NR HOST_FPX_SIZE
+
+void set_using_sysemu(int value);
+int get_using_sysemu(void);
+extern int sysemu_supported;
+
+#define UPT_SYSCALL_ARG1(r) UPT_BX(r)
+#define UPT_SYSCALL_ARG2(r) UPT_CX(r)
+#define UPT_SYSCALL_ARG3(r) UPT_DX(r)
+#define UPT_SYSCALL_ARG4(r) UPT_SI(r)
+#define UPT_SYSCALL_ARG5(r) UPT_DI(r)
+#define UPT_SYSCALL_ARG6(r) UPT_BP(r)
+
+extern void arch_init_registers(int pid);
+
+#endif
diff --git a/arch/x86/um/shared/sysdep/ptrace_64.h b/arch/x86/um/shared/sysdep/ptrace_64.h
new file mode 100644
index 0000000000..0dc223aa1c
--- /dev/null
+++ b/arch/x86/um/shared/sysdep/ptrace_64.h
@@ -0,0 +1,62 @@
+/*
+ * Copyright 2003 PathScale, Inc.
+ * Copyright (C) 2003 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+ *
+ * Licensed under the GPL
+ */
+
+#ifndef __SYSDEP_X86_64_PTRACE_H
+#define __SYSDEP_X86_64_PTRACE_H
+
+#define MAX_FP_NR HOST_FP_SIZE
+
+#define REGS_R8(r) ((r)[HOST_R8])
+#define REGS_R9(r) ((r)[HOST_R9])
+#define REGS_R10(r) ((r)[HOST_R10])
+#define REGS_R11(r) ((r)[HOST_R11])
+#define REGS_R12(r) ((r)[HOST_R12])
+#define REGS_R13(r) ((r)[HOST_R13])
+#define REGS_R14(r) ((r)[HOST_R14])
+#define REGS_R15(r) ((r)[HOST_R15])
+
+#define HOST_FS_BASE 21
+#define HOST_GS_BASE 22
+#define HOST_DS 23
+#define HOST_ES 24
+#define HOST_FS 25
+#define HOST_GS 26
+
+/* Also defined in asm/ptrace-x86_64.h, but not in libc headers.  So, these
+ * are already defined for kernel code, but not for userspace code.
+ */
+#ifndef FS_BASE
+/* These aren't defined in ptrace.h, but exist in struct user_regs_struct,
+ * which is what x86_64 ptrace actually uses.
+ */
+#define FS_BASE (HOST_FS_BASE * sizeof(long))
+#define GS_BASE (HOST_GS_BASE * sizeof(long))
+#define DS (HOST_DS * sizeof(long))
+#define ES (HOST_ES * sizeof(long))
+#define FS (HOST_FS * sizeof(long))
+#define GS (HOST_GS * sizeof(long))
+#endif
+
+#define UPT_R8(r) REGS_R8((r)->gp)
+#define UPT_R9(r) REGS_R9((r)->gp)
+#define UPT_R10(r) REGS_R10((r)->gp)
+#define UPT_R11(r) REGS_R11((r)->gp)
+#define UPT_R12(r) REGS_R12((r)->gp)
+#define UPT_R13(r) REGS_R13((r)->gp)
+#define UPT_R14(r) REGS_R14((r)->gp)
+#define UPT_R15(r) REGS_R15((r)->gp)
+
+#define UPT_SYSCALL_ARG1(r) UPT_DI(r)
+#define UPT_SYSCALL_ARG2(r) UPT_SI(r)
+#define UPT_SYSCALL_ARG3(r) UPT_DX(r)
+#define UPT_SYSCALL_ARG4(r) UPT_R10(r)
+#define UPT_SYSCALL_ARG5(r) UPT_R8(r)
+#define UPT_SYSCALL_ARG6(r) UPT_R9(r)
+
+extern void arch_init_registers(int pid);
+
+#endif
diff --git a/arch/x86/um/shared/sysdep/ptrace_user.h b/arch/x86/um/shared/sysdep/ptrace_user.h
new file mode 100644
index 0000000000..44782bbad4
--- /dev/null
+++ b/arch/x86/um/shared/sysdep/ptrace_user.h
@@ -0,0 +1,28 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#include <generated/user_constants.h>
+
+#define PT_OFFSET(r) ((r) * sizeof(long))
+
+#define PT_SYSCALL_NR(regs) ((regs)[HOST_ORIG_AX])
+#define PT_SYSCALL_NR_OFFSET PT_OFFSET(HOST_ORIG_AX)
+
+#define PT_SYSCALL_RET_OFFSET PT_OFFSET(HOST_AX)
+
+#define REGS_IP_INDEX HOST_IP
+#define REGS_SP_INDEX HOST_SP
+
+#ifdef __i386__
+#define FP_SIZE ((HOST_FPX_SIZE > HOST_FP_SIZE) ? HOST_FPX_SIZE : HOST_FP_SIZE)
+#else
+#define FP_SIZE HOST_FP_SIZE
+
+/*
+ * x86_64 FC3 doesn't define this in /usr/include/linux/ptrace.h even though
+ * it's defined in the kernel's include/linux/ptrace.h. Additionally, use the
+ * 2.4 name and value for 2.4 host compatibility.
+ */
+#ifndef PTRACE_OLDSETOPTIONS
+#define PTRACE_OLDSETOPTIONS 21
+#endif
+
+#endif
diff --git a/arch/x86/um/shared/sysdep/stub.h b/arch/x86/um/shared/sysdep/stub.h
new file mode 100644
index 0000000000..ce0ca46ad3
--- /dev/null
+++ b/arch/x86/um/shared/sysdep/stub.h
@@ -0,0 +1,15 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#include <asm/unistd.h>
+#include <sys/mman.h>
+#include <signal.h>
+#include <as-layout.h>
+#include <stub-data.h>
+
+#ifdef __i386__
+#include "stub_32.h"
+#else
+#include "stub_64.h"
+#endif
+
+extern void stub_segv_handler(int, siginfo_t *, void *);
+extern void stub_clone_handler(void);
diff --git a/arch/x86/um/shared/sysdep/stub_32.h b/arch/x86/um/shared/sysdep/stub_32.h
new file mode 100644
index 0000000000..38fa894b65
--- /dev/null
+++ b/arch/x86/um/shared/sysdep/stub_32.h
@@ -0,0 +1,116 @@
+/*
+ * Copyright (C) 2004 Jeff Dike (jdike@addtoit.com)
+ * Licensed under the GPL
+ */
+
+#ifndef __SYSDEP_STUB_H
+#define __SYSDEP_STUB_H
+
+#include <asm/ptrace.h>
+#include <generated/asm-offsets.h>
+
+#define STUB_MMAP_NR __NR_mmap2
+#define MMAP_OFFSET(o) ((o) >> UM_KERN_PAGE_SHIFT)
+
+static inline long stub_syscall0(long syscall)
+{
+	long ret;
+
+	__asm__ volatile ("int $0x80" : "=a" (ret) : "0" (syscall));
+
+	return ret;
+}
+
+static inline long stub_syscall1(long syscall, long arg1)
+{
+	long ret;
+
+	__asm__ volatile ("int $0x80" : "=a" (ret) : "0" (syscall), "b" (arg1));
+
+	return ret;
+}
+
+static inline long stub_syscall2(long syscall, long arg1, long arg2)
+{
+	long ret;
+
+	__asm__ volatile ("int $0x80" : "=a" (ret) : "0" (syscall), "b" (arg1),
+			"c" (arg2));
+
+	return ret;
+}
+
+static inline long stub_syscall3(long syscall, long arg1, long arg2, long arg3)
+{
+	long ret;
+
+	__asm__ volatile ("int $0x80" : "=a" (ret) : "0" (syscall), "b" (arg1),
+			"c" (arg2), "d" (arg3));
+
+	return ret;
+}
+
+static inline long stub_syscall4(long syscall, long arg1, long arg2, long arg3,
+				 long arg4)
+{
+	long ret;
+
+	__asm__ volatile ("int $0x80" : "=a" (ret) : "0" (syscall), "b" (arg1),
+			"c" (arg2), "d" (arg3), "S" (arg4));
+
+	return ret;
+}
+
+static inline long stub_syscall5(long syscall, long arg1, long arg2, long arg3,
+				 long arg4, long arg5)
+{
+	long ret;
+
+	__asm__ volatile ("int $0x80" : "=a" (ret) : "0" (syscall), "b" (arg1),
+			"c" (arg2), "d" (arg3), "S" (arg4), "D" (arg5));
+
+	return ret;
+}
+
+static inline void trap_myself(void)
+{
+	__asm("int3");
+}
+
+static inline void remap_stack_and_trap(void)
+{
+	__asm__ volatile (
+		"movl %%esp,%%ebx ;"
+		"andl %0,%%ebx ;"
+		"movl %1,%%eax ;"
+		"movl %%ebx,%%edi ; addl %2,%%edi ; movl (%%edi),%%edi ;"
+		"movl %%ebx,%%ebp ; addl %3,%%ebp ; movl (%%ebp),%%ebp ;"
+		"int $0x80 ;"
+		"addl %4,%%ebx ; movl %%eax, (%%ebx) ;"
+		"int $3"
+		: :
+		"g" (~(STUB_DATA_PAGES * UM_KERN_PAGE_SIZE - 1)),
+		"g" (STUB_MMAP_NR),
+		"g" (UML_STUB_FIELD_FD),
+		"g" (UML_STUB_FIELD_OFFSET),
+		"g" (UML_STUB_FIELD_CHILD_ERR),
+		"c" (STUB_DATA_PAGES * UM_KERN_PAGE_SIZE),
+		"d" (PROT_READ | PROT_WRITE),
+		"S" (MAP_FIXED | MAP_SHARED)
+		:
+		"memory");
+}
+
+static __always_inline void *get_stub_data(void)
+{
+	unsigned long ret;
+
+	asm volatile (
+		"movl %%esp,%0 ;"
+		"andl %1,%0"
+		: "=a" (ret)
+		: "g" (~(STUB_DATA_PAGES * UM_KERN_PAGE_SIZE - 1)));
+
+	return (void *)ret;
+}
+#endif
diff --git a/arch/x86/um/shared/sysdep/stub_64.h b/arch/x86/um/shared/sysdep/stub_64.h
new file mode 100644
index 0000000000..2de1c8f881
--- /dev/null
+++ b/arch/x86/um/shared/sysdep/stub_64.h
@@ -0,0 +1,124 @@
+/*
+ * Copyright (C) 2004 Jeff Dike (jdike@addtoit.com)
+ * Licensed under the GPL
+ */
+
+#ifndef __SYSDEP_STUB_H
+#define __SYSDEP_STUB_H
+
+#include <sysdep/ptrace_user.h>
+#include <generated/asm-offsets.h>
+#include <linux/stddef.h>
+
+#define STUB_MMAP_NR __NR_mmap
+#define MMAP_OFFSET(o) (o)
+
+#define __syscall_clobber "r11","rcx","memory"
+#define __syscall "syscall"
+
+static inline long stub_syscall0(long syscall)
+{
+	long ret;
+
+	__asm__ volatile (__syscall
+		: "=a" (ret)
+		: "0" (syscall) : __syscall_clobber );
+
+	return ret;
+}
+
+static inline long stub_syscall2(long syscall, long arg1, long arg2)
+{
+	long ret;
+
+	__asm__ volatile (__syscall
+		: "=a" (ret)
+		: "0" (syscall), "D" (arg1), "S" (arg2) : __syscall_clobber );
+
+	return ret;
+}
+
+static inline long stub_syscall3(long syscall, long arg1, long arg2, long arg3)
+{
+	long ret;
+
+	__asm__ volatile (__syscall
+		: "=a" (ret)
+		: "0" (syscall), "D" (arg1), "S" (arg2), "d" (arg3)
+		: __syscall_clobber );
+
+	return ret;
+}
+
+static inline long stub_syscall4(long syscall, long arg1, long arg2, long arg3,
+				 long arg4)
+{
+	long ret;
+
+	__asm__ volatile ("movq %5,%%r10 ; " __syscall
+		: "=a" (ret)
+		: "0" (syscall), "D" (arg1), "S" (arg2), "d" (arg3),
+		  "g" (arg4)
+		: __syscall_clobber, "r10" );
+
+	return ret;
+}
+
+static inline long stub_syscall5(long syscall, long arg1, long arg2, long arg3,
+				 long arg4, long arg5)
+{
+	long ret;
+
+	__asm__ volatile ("movq %5,%%r10 ; movq %6,%%r8 ; " __syscall
+		: "=a" (ret)
+		: "0" (syscall), "D" (arg1), "S" (arg2), "d" (arg3),
+		  "g" (arg4), "g" (arg5)
+		: __syscall_clobber, "r10", "r8" );
+
+	return ret;
+}
+
+static inline void trap_myself(void)
+{
+	__asm("int3");
+}
+
+static inline void remap_stack_and_trap(void)
+{
+	__asm__ volatile (
+		"movq %0,%%rax ;"
+		"movq %%rsp,%%rdi ;"
+		"andq %1,%%rdi ;"
+		"movq %2,%%r10 ;"
+		"movq %%rdi,%%r8 ; addq %3,%%r8 ; movq (%%r8),%%r8 ;"
+		"movq %%rdi,%%r9 ; addq %4,%%r9 ; movq (%%r9),%%r9 ;"
+		__syscall ";"
+		"movq %%rsp,%%rdi ; andq %1,%%rdi ;"
+		"addq %5,%%rdi ; movq %%rax, (%%rdi) ;"
+		"int3"
+		: :
+		"g" (STUB_MMAP_NR),
+		"g" (~(STUB_DATA_PAGES * UM_KERN_PAGE_SIZE - 1)),
+		"g" (MAP_FIXED | MAP_SHARED),
+		"g" (UML_STUB_FIELD_FD),
+		"g" (UML_STUB_FIELD_OFFSET),
+		"g" (UML_STUB_FIELD_CHILD_ERR),
+		"S" (STUB_DATA_PAGES * UM_KERN_PAGE_SIZE),
+		"d" (PROT_READ | PROT_WRITE)
+		:
+		__syscall_clobber, "r10", "r8", "r9");
+}
+
+static __always_inline void *get_stub_data(void)
+{
+	unsigned long ret;
+
+	asm volatile (
+		"movq %%rsp,%0 ;"
+		"andq %1,%0"
+		: "=a" (ret)
+		: "g" (~(STUB_DATA_PAGES * UM_KERN_PAGE_SIZE - 1)));
+
+	return (void *)ret;
+}
+#endif
diff --git a/arch/x86/um/shared/sysdep/syscalls.h b/arch/x86/um/shared/sysdep/syscalls.h
new file mode 100644
index 0000000000..b2060ac707
--- /dev/null
+++ b/arch/x86/um/shared/sysdep/syscalls.h
@@ -0,0 +1,6 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifdef __i386__
+#include "syscalls_32.h"
+#else
+#include "syscalls_64.h"
+#endif
diff --git a/arch/x86/um/shared/sysdep/syscalls_32.h b/arch/x86/um/shared/sysdep/syscalls_32.h
new file mode 100644
index 0000000000..f6e9f84397
--- /dev/null
+++ b/arch/x86/um/shared/sysdep/syscalls_32.h
@@ -0,0 +1,14 @@
+/* 
+ * Copyright (C) 2000 - 2008 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+ * Licensed under the GPL
+ */
+
+#include <asm/unistd.h>
+#include <sysdep/ptrace.h>
+
+typedef long syscall_handler_t(struct syscall_args);
+
+extern syscall_handler_t *sys_call_table[];
+
+#define EXECUTE_SYSCALL(syscall, regs) \
+	((*sys_call_table[syscall]))(SYSCALL_ARGS(&regs->regs))
diff --git a/arch/x86/um/shared/sysdep/syscalls_64.h b/arch/x86/um/shared/sysdep/syscalls_64.h
new file mode 100644
index 0000000000..b6b9972258
--- /dev/null
+++ b/arch/x86/um/shared/sysdep/syscalls_64.h
@@ -0,0 +1,28 @@
+/*
+ * Copyright 2003 PathScale, Inc.
+ *
+ * Licensed under the GPL
+ */
+
+#ifndef __SYSDEP_X86_64_SYSCALLS_H__
+#define __SYSDEP_X86_64_SYSCALLS_H__
+
+#include <linux/msg.h>
+#include <linux/shm.h>
+
+typedef long syscall_handler_t(long, long, long, long, long, long);
+
+extern syscall_handler_t *sys_call_table[];
+
+#define EXECUTE_SYSCALL(syscall, regs) \
+	(((*sys_call_table[syscall]))(UPT_SYSCALL_ARG1(&regs->regs), \
+		 		      UPT_SYSCALL_ARG2(&regs->regs), \
+				      UPT_SYSCALL_ARG3(&regs->regs), \
+				      UPT_SYSCALL_ARG4(&regs->regs), \
+				      UPT_SYSCALL_ARG5(&regs->regs), \
+				      UPT_SYSCALL_ARG6(&regs->regs)))
+
+extern syscall_handler_t sys_modify_ldt;
+extern syscall_handler_t sys_arch_prctl;
+
+#endif
diff --git a/arch/x86/um/shared/sysdep/tls.h b/arch/x86/um/shared/sysdep/tls.h
new file mode 100644
index 0000000000..b968016aa3
--- /dev/null
+++ b/arch/x86/um/shared/sysdep/tls.h
@@ -0,0 +1,40 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _SYSDEP_TLS_H
+#define _SYSDEP_TLS_H
+
+#ifdef __UM_HOST__
+
+/* Change name to avoid conflicts with the original one from <asm/ldt.h>, which
+ * may be named user_desc (but in 2.4 and in header matching its API was named
+ * modify_ldt_ldt_s). */
+
+typedef struct um_dup_user_desc {
+	unsigned int  entry_number;
+	unsigned int  base_addr;
+	unsigned int  limit;
+	unsigned int  seg_32bit:1;
+	unsigned int  contents:2;
+	unsigned int  read_exec_only:1;
+	unsigned int  limit_in_pages:1;
+	unsigned int  seg_not_present:1;
+	unsigned int  useable:1;
+#ifdef __x86_64__
+	unsigned int  lm:1;
+#endif
+} user_desc_t;
+
+#else /* __UM_HOST__ */
+
+typedef struct user_desc user_desc_t;
+
+#endif /* __UM_HOST__ */
+
+extern int os_set_thread_area(user_desc_t *info, int pid);
+extern int os_get_thread_area(user_desc_t *info, int pid);
+
+#ifdef __i386__
+#define GDT_ENTRY_TLS_MIN_I386 6
+#define GDT_ENTRY_TLS_MIN_X86_64 12
+#endif
+
+#endif /* _SYSDEP_TLS_H */
diff --git a/arch/x86/um/signal.c b/arch/x86/um/signal.c
new file mode 100644
index 0000000000..263e1d08f2
--- /dev/null
+++ b/arch/x86/um/signal.c
@@ -0,0 +1,583 @@
+/*
+ * Copyright (C) 2003 PathScale, Inc.
+ * Copyright (C) 2003 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+ * Licensed under the GPL
+ */
+
+
+#include <linux/personality.h>
+#include <linux/ptrace.h>
+#include <linux/kernel.h>
+#include <asm/unistd.h>
+#include <linux/uaccess.h>
+#include <asm/ucontext.h>
+#include <frame_kern.h>
+#include <registers.h>
+#include <skas.h>
+
+#ifdef CONFIG_X86_32
+
+/*
+ * FPU tag word conversions.
+ */
+
+static inline unsigned short twd_i387_to_fxsr(unsigned short twd)
+{
+	unsigned int tmp; /* to avoid 16 bit prefixes in the code */
+
+	/* Transform each pair of bits into 01 (valid) or 00 (empty) */
+	tmp = ~twd;
+	tmp = (tmp | (tmp>>1)) & 0x5555; /* 0V0V0V0V0V0V0V0V */
+	/* and move the valid bits to the lower byte. */
+	tmp = (tmp | (tmp >> 1)) & 0x3333; /* 00VV00VV00VV00VV */
+	tmp = (tmp | (tmp >> 2)) & 0x0f0f; /* 0000VVVV0000VVVV */
+	tmp = (tmp | (tmp >> 4)) & 0x00ff; /* 00000000VVVVVVVV */
+	return tmp;
+}
+
+static inline unsigned long twd_fxsr_to_i387(struct user_fxsr_struct *fxsave)
+{
+	struct _fpxreg *st = NULL;
+	unsigned long twd = (unsigned long) fxsave->twd;
+	unsigned long tag;
+	unsigned long ret = 0xffff0000;
+	int i;
+
+#define FPREG_ADDR(f, n)	((char *)&(f)->st_space + (n) * 16)
+
+	for (i = 0; i < 8; i++) {
+		if (twd & 0x1) {
+			st = (struct _fpxreg *) FPREG_ADDR(fxsave, i);
+
+			switch (st->exponent & 0x7fff) {
+			case 0x7fff:
+				tag = 2;		/* Special */
+				break;
+			case 0x0000:
+				if ( !st->significand[0] &&
+				     !st->significand[1] &&
+				     !st->significand[2] &&
+				     !st->significand[3] ) {
+					tag = 1;	/* Zero */
+				} else {
+					tag = 2;	/* Special */
+				}
+				break;
+			default:
+				if (st->significand[3] & 0x8000) {
+					tag = 0;	/* Valid */
+				} else {
+					tag = 2;	/* Special */
+				}
+				break;
+			}
+		} else {
+			tag = 3;			/* Empty */
+		}
+		ret |= (tag << (2 * i));
+		twd = twd >> 1;
+	}
+	return ret;
+}
+
+static int convert_fxsr_to_user(struct _fpstate __user *buf,
+				struct user_fxsr_struct *fxsave)
+{
+	unsigned long env[7];
+	struct _fpreg __user *to;
+	struct _fpxreg *from;
+	int i;
+
+	env[0] = (unsigned long)fxsave->cwd | 0xffff0000ul;
+	env[1] = (unsigned long)fxsave->swd | 0xffff0000ul;
+	env[2] = twd_fxsr_to_i387(fxsave);
+	env[3] = fxsave->fip;
+	env[4] = fxsave->fcs | ((unsigned long)fxsave->fop << 16);
+	env[5] = fxsave->foo;
+	env[6] = fxsave->fos;
+
+	if (__copy_to_user(buf, env, 7 * sizeof(unsigned long)))
+		return 1;
+
+	to = &buf->_st[0];
+	from = (struct _fpxreg *) &fxsave->st_space[0];
+	for (i = 0; i < 8; i++, to++, from++) {
+		unsigned long __user *t = (unsigned long __user *)to;
+		unsigned long *f = (unsigned long *)from;
+
+		if (__put_user(*f, t) ||
+				__put_user(*(f + 1), t + 1) ||
+				__put_user(from->exponent, &to->exponent))
+			return 1;
+	}
+	return 0;
+}
+
+static int convert_fxsr_from_user(struct user_fxsr_struct *fxsave,
+				  struct _fpstate __user *buf)
+{
+	unsigned long env[7];
+	struct _fpxreg *to;
+	struct _fpreg __user *from;
+	int i;
+
+	if (copy_from_user( env, buf, 7 * sizeof(long)))
+		return 1;
+
+	fxsave->cwd = (unsigned short)(env[0] & 0xffff);
+	fxsave->swd = (unsigned short)(env[1] & 0xffff);
+	fxsave->twd = twd_i387_to_fxsr((unsigned short)(env[2] & 0xffff));
+	fxsave->fip = env[3];
+	fxsave->fop = (unsigned short)((env[4] & 0xffff0000ul) >> 16);
+	fxsave->fcs = (env[4] & 0xffff);
+	fxsave->foo = env[5];
+	fxsave->fos = env[6];
+
+	to = (struct _fpxreg *) &fxsave->st_space[0];
+	from = &buf->_st[0];
+	for (i = 0; i < 8; i++, to++, from++) {
+		unsigned long *t = (unsigned long *)to;
+		unsigned long __user *f = (unsigned long __user *)from;
+
+		if (__get_user(*t, f) ||
+		    __get_user(*(t + 1), f + 1) ||
+		    __get_user(to->exponent, &from->exponent))
+			return 1;
+	}
+	return 0;
+}
+
+extern int have_fpx_regs;
+
+#endif
+
+static int copy_sc_from_user(struct pt_regs *regs,
+			     struct sigcontext __user *from)
+{
+	struct sigcontext sc;
+	int err, pid;
+
+	/* Always make any pending restarted system calls return -EINTR */
+	current->restart_block.fn = do_no_restart_syscall;
+
+	err = copy_from_user(&sc, from, sizeof(sc));
+	if (err)
+		return err;
+
+#define GETREG(regno, regname) regs->regs.gp[HOST_##regno] = sc.regname
+
+#ifdef CONFIG_X86_32
+	GETREG(GS, gs);
+	GETREG(FS, fs);
+	GETREG(ES, es);
+	GETREG(DS, ds);
+#endif
+	GETREG(DI, di);
+	GETREG(SI, si);
+	GETREG(BP, bp);
+	GETREG(SP, sp);
+	GETREG(BX, bx);
+	GETREG(DX, dx);
+	GETREG(CX, cx);
+	GETREG(AX, ax);
+	GETREG(IP, ip);
+
+#ifdef CONFIG_X86_64
+	GETREG(R8, r8);
+	GETREG(R9, r9);
+	GETREG(R10, r10);
+	GETREG(R11, r11);
+	GETREG(R12, r12);
+	GETREG(R13, r13);
+	GETREG(R14, r14);
+	GETREG(R15, r15);
+#endif
+
+	GETREG(CS, cs);
+	GETREG(EFLAGS, flags);
+#ifdef CONFIG_X86_32
+	GETREG(SS, ss);
+#endif
+
+#undef GETREG
+
+	pid = userspace_pid[current_thread_info()->cpu];
+#ifdef CONFIG_X86_32
+	if (have_fpx_regs) {
+		struct user_fxsr_struct fpx;
+
+		err = copy_from_user(&fpx,
+			&((struct _fpstate __user *)sc.fpstate)->_fxsr_env[0],
+				     sizeof(struct user_fxsr_struct));
+		if (err)
+			return 1;
+
+		err = convert_fxsr_from_user(&fpx, (void *)sc.fpstate);
+		if (err)
+			return 1;
+
+		err = restore_fpx_registers(pid, (unsigned long *) &fpx);
+		if (err < 0) {
+			printk(KERN_ERR "copy_sc_from_user - "
+			       "restore_fpx_registers failed, errno = %d\n",
+			       -err);
+			return 1;
+		}
+	} else
+#endif
+	{
+		err = copy_from_user(regs->regs.fp, (void *)sc.fpstate,
+				     sizeof(struct _xstate));
+		if (err)
+			return 1;
+	}
+	return 0;
+}
+
+static int copy_sc_to_user(struct sigcontext __user *to,
+			   struct _xstate __user *to_fp, struct pt_regs *regs,
+			   unsigned long mask)
+{
+	struct sigcontext sc;
+	struct faultinfo * fi = &current->thread.arch.faultinfo;
+	int err, pid;
+	memset(&sc, 0, sizeof(struct sigcontext));
+
+#define PUTREG(regno, regname) sc.regname = regs->regs.gp[HOST_##regno]
+
+#ifdef CONFIG_X86_32
+	PUTREG(GS, gs);
+	PUTREG(FS, fs);
+	PUTREG(ES, es);
+	PUTREG(DS, ds);
+#endif
+	PUTREG(DI, di);
+	PUTREG(SI, si);
+	PUTREG(BP, bp);
+	PUTREG(SP, sp);
+	PUTREG(BX, bx);
+	PUTREG(DX, dx);
+	PUTREG(CX, cx);
+	PUTREG(AX, ax);
+#ifdef CONFIG_X86_64
+	PUTREG(R8, r8);
+	PUTREG(R9, r9);
+	PUTREG(R10, r10);
+	PUTREG(R11, r11);
+	PUTREG(R12, r12);
+	PUTREG(R13, r13);
+	PUTREG(R14, r14);
+	PUTREG(R15, r15);
+#endif
+
+	sc.cr2 = fi->cr2;
+	sc.err = fi->error_code;
+	sc.trapno = fi->trap_no;
+	PUTREG(IP, ip);
+	PUTREG(CS, cs);
+	PUTREG(EFLAGS, flags);
+#ifdef CONFIG_X86_32
+	PUTREG(SP, sp_at_signal);
+	PUTREG(SS, ss);
+#endif
+#undef PUTREG
+	sc.oldmask = mask;
+	sc.fpstate = (unsigned long)to_fp;
+
+	err = copy_to_user(to, &sc, sizeof(struct sigcontext));
+	if (err)
+		return 1;
+
+	pid = userspace_pid[current_thread_info()->cpu];
+
+#ifdef CONFIG_X86_32
+	if (have_fpx_regs) {
+		struct user_fxsr_struct fpx;
+
+		err = save_fpx_registers(pid, (unsigned long *) &fpx);
+		if (err < 0){
+			printk(KERN_ERR "copy_sc_to_user - save_fpx_registers "
+			       "failed, errno = %d\n", err);
+			return 1;
+		}
+
+		err = convert_fxsr_to_user(&to_fp->fpstate, &fpx);
+		if (err)
+			return 1;
+
+		err |= __put_user(fpx.swd, &to_fp->fpstate.status);
+		err |= __put_user(X86_FXSR_MAGIC, &to_fp->fpstate.magic);
+		if (err)
+			return 1;
+
+		if (copy_to_user(&to_fp->fpstate._fxsr_env[0], &fpx,
+				 sizeof(struct user_fxsr_struct)))
+			return 1;
+	} else
+#endif
+	{
+		if (copy_to_user(to_fp, regs->regs.fp, sizeof(struct _xstate)))
+			return 1;
+	}
+
+	return 0;
+}
+
+#ifdef CONFIG_X86_32
+static int copy_ucontext_to_user(struct ucontext __user *uc,
+				 struct _xstate __user *fp, sigset_t *set,
+				 unsigned long sp)
+{
+	int err = 0;
+
+	err |= __save_altstack(&uc->uc_stack, sp);
+	err |= copy_sc_to_user(&uc->uc_mcontext, fp, &current->thread.regs, 0);
+	err |= copy_to_user(&uc->uc_sigmask, set, sizeof(*set));
+	return err;
+}
+
+struct sigframe
+{
+	char __user *pretcode;
+	int sig;
+	struct sigcontext sc;
+	struct _xstate fpstate;
+	unsigned long extramask[_NSIG_WORDS-1];
+	char retcode[8];
+};
+
+struct rt_sigframe
+{
+	char __user *pretcode;
+	int sig;
+	struct siginfo __user *pinfo;
+	void __user *puc;
+	struct siginfo info;
+	struct ucontext uc;
+	struct _xstate fpstate;
+	char retcode[8];
+};
+
+int setup_signal_stack_sc(unsigned long stack_top, struct ksignal *ksig,
+			  struct pt_regs *regs, sigset_t *mask)
+{
+	struct sigframe __user *frame;
+	void __user *restorer;
+	int err = 0, sig = ksig->sig;
+
+	/* This is the same calculation as i386 - ((sp + 4) & 15) == 0 */
+	stack_top = ((stack_top + 4) & -16UL) - 4;
+	frame = (struct sigframe __user *) stack_top - 1;
+	if (!access_ok(frame, sizeof(*frame)))
+		return 1;
+
+	restorer = frame->retcode;
+	if (ksig->ka.sa.sa_flags & SA_RESTORER)
+		restorer = ksig->ka.sa.sa_restorer;
+
+	err |= __put_user(restorer, &frame->pretcode);
+	err |= __put_user(sig, &frame->sig);
+	err |= copy_sc_to_user(&frame->sc, &frame->fpstate, regs, mask->sig[0]);
+	if (_NSIG_WORDS > 1)
+		err |= __copy_to_user(&frame->extramask, &mask->sig[1],
+				      sizeof(frame->extramask));
+
+	/*
+	 * This is popl %eax ; movl $,%eax ; int $0x80
+	 *
+	 * WE DO NOT USE IT ANY MORE! It's only left here for historical
+	 * reasons and because gdb uses it as a signature to notice
+	 * signal handler stack frames.
+	 */
+	err |= __put_user(0xb858, (short __user *)(frame->retcode+0));
+	err |= __put_user(__NR_sigreturn, (int __user *)(frame->retcode+2));
+	err |= __put_user(0x80cd, (short __user *)(frame->retcode+6));
+
+	if (err)
+		return err;
+
+	PT_REGS_SP(regs) = (unsigned long) frame;
+	PT_REGS_IP(regs) = (unsigned long) ksig->ka.sa.sa_handler;
+	PT_REGS_AX(regs) = (unsigned long) sig;
+	PT_REGS_DX(regs) = (unsigned long) 0;
+	PT_REGS_CX(regs) = (unsigned long) 0;
+	return 0;
+}
+
+int setup_signal_stack_si(unsigned long stack_top, struct ksignal *ksig,
+			  struct pt_regs *regs, sigset_t *mask)
+{
+	struct rt_sigframe __user *frame;
+	void __user *restorer;
+	int err = 0, sig = ksig->sig;
+
+	stack_top &= -8UL;
+	frame = (struct rt_sigframe __user *) stack_top - 1;
+	if (!access_ok(frame, sizeof(*frame)))
+		return 1;
+
+	restorer = frame->retcode;
+	if (ksig->ka.sa.sa_flags & SA_RESTORER)
+		restorer = ksig->ka.sa.sa_restorer;
+
+	err |= __put_user(restorer, &frame->pretcode);
+	err |= __put_user(sig, &frame->sig);
+	err |= __put_user(&frame->info, &frame->pinfo);
+	err |= __put_user(&frame->uc, &frame->puc);
+	err |= copy_siginfo_to_user(&frame->info, &ksig->info);
+	err |= copy_ucontext_to_user(&frame->uc, &frame->fpstate, mask,
+					PT_REGS_SP(regs));
+
+	/*
+	 * This is movl $,%eax ; int $0x80
+	 *
+	 * WE DO NOT USE IT ANY MORE! It's only left here for historical
+	 * reasons and because gdb uses it as a signature to notice
+	 * signal handler stack frames.
+	 */
+	err |= __put_user(0xb8, (char __user *)(frame->retcode+0));
+	err |= __put_user(__NR_rt_sigreturn, (int __user *)(frame->retcode+1));
+	err |= __put_user(0x80cd, (short __user *)(frame->retcode+5));
+
+	if (err)
+		return err;
+
+	PT_REGS_SP(regs) = (unsigned long) frame;
+	PT_REGS_IP(regs) = (unsigned long) ksig->ka.sa.sa_handler;
+	PT_REGS_AX(regs) = (unsigned long) sig;
+	PT_REGS_DX(regs) = (unsigned long) &frame->info;
+	PT_REGS_CX(regs) = (unsigned long) &frame->uc;
+	return 0;
+}
+
+long sys_sigreturn(void)
+{
+	unsigned long sp = PT_REGS_SP(&current->thread.regs);
+	struct sigframe __user *frame = (struct sigframe __user *)(sp - 8);
+	sigset_t set;
+	struct sigcontext __user *sc = &frame->sc;
+	int sig_size = (_NSIG_WORDS - 1) * sizeof(unsigned long);
+
+	if (copy_from_user(&set.sig[0], &sc->oldmask, sizeof(set.sig[0])) ||
+	    copy_from_user(&set.sig[1], frame->extramask, sig_size))
+		goto segfault;
+
+	set_current_blocked(&set);
+
+	if (copy_sc_from_user(&current->thread.regs, sc))
+		goto segfault;
+
+	/* Avoid ERESTART handling */
+	PT_REGS_SYSCALL_NR(&current->thread.regs) = -1;
+	return PT_REGS_SYSCALL_RET(&current->thread.regs);
+
+ segfault:
+	force_sig(SIGSEGV);
+	return 0;
+}
+
+#else
+
+struct rt_sigframe
+{
+	char __user *pretcode;
+	struct ucontext uc;
+	struct siginfo info;
+	struct _xstate fpstate;
+};
+
+int setup_signal_stack_si(unsigned long stack_top, struct ksignal *ksig,
+			  struct pt_regs *regs, sigset_t *set)
+{
+	struct rt_sigframe __user *frame;
+	int err = 0, sig = ksig->sig;
+	unsigned long fp_to;
+
+	frame = (struct rt_sigframe __user *)
+		round_down(stack_top - sizeof(struct rt_sigframe), 16);
+	/* Subtract 128 for a red zone and 8 for proper alignment */
+	frame = (struct rt_sigframe __user *) ((unsigned long) frame - 128 - 8);
+
+	if (!access_ok(frame, sizeof(*frame)))
+		goto out;
+
+	if (ksig->ka.sa.sa_flags & SA_SIGINFO) {
+		err |= copy_siginfo_to_user(&frame->info, &ksig->info);
+		if (err)
+			goto out;
+	}
+
+	/* Create the ucontext.  */
+	err |= __put_user(0, &frame->uc.uc_flags);
+	err |= __put_user(0, &frame->uc.uc_link);
+	err |= __save_altstack(&frame->uc.uc_stack, PT_REGS_SP(regs));
+	err |= copy_sc_to_user(&frame->uc.uc_mcontext, &frame->fpstate, regs,
+			       set->sig[0]);
+
+	fp_to = (unsigned long)&frame->fpstate;
+
+	err |= __put_user(fp_to, &frame->uc.uc_mcontext.fpstate);
+	if (sizeof(*set) == 16) {
+		err |= __put_user(set->sig[0], &frame->uc.uc_sigmask.sig[0]);
+		err |= __put_user(set->sig[1], &frame->uc.uc_sigmask.sig[1]);
+	}
+	else
+		err |= __copy_to_user(&frame->uc.uc_sigmask, set,
+				      sizeof(*set));
+
+	/*
+	 * Set up to return from userspace.  If provided, use a stub
+	 * already in userspace.
+	 */
+	/* x86-64 should always use SA_RESTORER. */
+	if (ksig->ka.sa.sa_flags & SA_RESTORER)
+		err |= __put_user((void *)ksig->ka.sa.sa_restorer,
+				  &frame->pretcode);
+	else
+		/* could use a vstub here */
+		return err;
+
+	if (err)
+		return err;
+
+	PT_REGS_SP(regs) = (unsigned long) frame;
+	PT_REGS_DI(regs) = sig;
+	/* In case the signal handler was declared without prototypes */
+	PT_REGS_AX(regs) = 0;
+
+	/*
+	 * This also works for non SA_SIGINFO handlers because they expect the
+	 * next argument after the signal number on the stack.
+	 */
+	PT_REGS_SI(regs) = (unsigned long) &frame->info;
+	PT_REGS_DX(regs) = (unsigned long) &frame->uc;
+	PT_REGS_IP(regs) = (unsigned long) ksig->ka.sa.sa_handler;
+ out:
+	return err;
+}
+#endif
+
+long sys_rt_sigreturn(void)
+{
+	unsigned long sp = PT_REGS_SP(&current->thread.regs);
+	struct rt_sigframe __user *frame =
+		(struct rt_sigframe __user *)(sp - sizeof(long));
+	struct ucontext __user *uc = &frame->uc;
+	sigset_t set;
+
+	if (copy_from_user(&set, &uc->uc_sigmask, sizeof(set)))
+		goto segfault;
+
+	set_current_blocked(&set);
+
+	if (copy_sc_from_user(&current->thread.regs, &uc->uc_mcontext))
+		goto segfault;
+
+	/* Avoid ERESTART handling */
+	PT_REGS_SYSCALL_NR(&current->thread.regs) = -1;
+	return PT_REGS_SYSCALL_RET(&current->thread.regs);
+
+ segfault:
+	force_sig(SIGSEGV);
+	return 0;
+}
diff --git a/arch/x86/um/stub_32.S b/arch/x86/um/stub_32.S
new file mode 100644
index 0000000000..8291899e6a
--- /dev/null
+++ b/arch/x86/um/stub_32.S
@@ -0,0 +1,56 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#include <as-layout.h>
+
+.section .__syscall_stub, "ax"
+
+	.globl batch_syscall_stub
+batch_syscall_stub:
+	/* %esp comes in as "top of page" */
+	mov %esp, %ecx
+	/* %esp has pointer to first operation */
+	add $8, %esp
+again:
+	/* load length of additional data */
+	mov	0x0(%esp), %eax
+
+	/* if(length == 0) : end of list */
+	/* write possible 0 to header */
+	mov	%eax, 0x4(%ecx)
+	cmpl	$0, %eax
+	jz	done
+
+	/* save current pointer */
+	mov	%esp, 0x4(%ecx)
+
+	/* skip additional data */
+	add	%eax, %esp
+
+	/* load syscall-# */
+	pop	%eax
+
+	/* load syscall params */
+	pop	%ebx
+	pop	%ecx
+	pop	%edx
+	pop	%esi
+ 	pop	%edi
+	pop	%ebp
+
+	/* execute syscall */
+	int	$0x80
+
+	/* restore top of page pointer in %ecx */
+	mov	%esp, %ecx
+	andl	$(~UM_KERN_PAGE_SIZE) + 1, %ecx
+
+	/* check return value */
+	pop	%ebx
+	cmp	%ebx, %eax
+	je	again
+
+done:
+	/* save return value */
+	mov	%eax, (%ecx)
+
+	/* stop */
+	int3
diff --git a/arch/x86/um/stub_64.S b/arch/x86/um/stub_64.S
new file mode 100644
index 0000000000..f340464019
--- /dev/null
+++ b/arch/x86/um/stub_64.S
@@ -0,0 +1,50 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#include <as-layout.h>
+
+.section .__syscall_stub, "ax"
+	.globl batch_syscall_stub
+batch_syscall_stub:
+	/* %rsp has the pointer to first operation */
+	mov	%rsp, %rbx
+	add	$0x10, %rsp
+again:
+	/* load length of additional data */
+	mov	0x0(%rsp), %rax
+
+	/* if(length == 0) : end of list */
+	/* write possible 0 to header */
+	mov	%rax, 8(%rbx)
+	cmp	$0, %rax
+	jz	done
+
+	/* save current pointer */
+	mov	%rsp, 8(%rbx)
+
+	/* skip additional data */
+	add	%rax, %rsp
+
+	/* load syscall-# */
+	pop	%rax
+
+	/* load syscall params */
+	pop	%rdi
+	pop	%rsi
+	pop	%rdx
+	pop	%r10
+ 	pop	%r8
+	pop	%r9
+
+	/* execute syscall */
+	syscall
+
+	/* check return value */
+	pop	%rcx
+	cmp	%rcx, %rax
+	je	again
+
+done:
+	/* save return value */
+	mov	%rax, (%rbx)
+
+	/* stop */
+	int3
diff --git a/arch/x86/um/stub_segv.c b/arch/x86/um/stub_segv.c
new file mode 100644
index 0000000000..040668b989
--- /dev/null
+++ b/arch/x86/um/stub_segv.c
@@ -0,0 +1,20 @@
+/*
+ * Copyright (C) 2004 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+ * Licensed under the GPL
+ */
+
+#include <sysdep/stub.h>
+#include <sysdep/faultinfo.h>
+#include <sysdep/mcontext.h>
+#include <sys/ucontext.h>
+
+void __attribute__ ((__section__ (".__syscall_stub")))
+stub_segv_handler(int sig, siginfo_t *info, void *p)
+{
+	struct faultinfo *f = get_stub_data();
+	ucontext_t *uc = p;
+
+	GET_FAULTINFO_FROM_MC(*f, &uc->uc_mcontext);
+	trap_myself();
+}
+
diff --git a/arch/x86/um/sys_call_table_32.c b/arch/x86/um/sys_call_table_32.c
new file mode 100644
index 0000000000..89df5d89d6
--- /dev/null
+++ b/arch/x86/um/sys_call_table_32.c
@@ -0,0 +1,38 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * System call table for UML/i386, copied from arch/x86/kernel/syscall_*.c
+ * with some changes for UML.
+ */
+
+#include <linux/linkage.h>
+#include <linux/sys.h>
+#include <linux/cache.h>
+#include <asm/syscall.h>
+
+/*
+ * Below you can see, in terms of #define's, the differences between the x86-64
+ * and the UML syscall table.
+ */
+
+/* Not going to be implemented by UML, since we have no hardware. */
+#define sys_iopl sys_ni_syscall
+#define sys_ioperm sys_ni_syscall
+
+#define sys_vm86old sys_ni_syscall
+#define sys_vm86 sys_ni_syscall
+
+#define __SYSCALL_WITH_COMPAT(nr, native, compat)	__SYSCALL(nr, native)
+
+#define __SYSCALL(nr, sym) extern asmlinkage long sym(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long);
+#include <asm/syscalls_32.h>
+
+#undef __SYSCALL
+#define __SYSCALL(nr, sym) sym,
+
+extern asmlinkage long sys_ni_syscall(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long);
+
+const sys_call_ptr_t sys_call_table[] ____cacheline_aligned = {
+#include <asm/syscalls_32.h>
+};
+
+int syscall_table_size = sizeof(sys_call_table);
diff --git a/arch/x86/um/sys_call_table_64.c b/arch/x86/um/sys_call_table_64.c
new file mode 100644
index 0000000000..b0b4cfd230
--- /dev/null
+++ b/arch/x86/um/sys_call_table_64.c
@@ -0,0 +1,33 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * System call table for UML/x86-64, copied from arch/x86/kernel/syscall_*.c
+ * with some changes for UML.
+ */
+
+#include <linux/linkage.h>
+#include <linux/sys.h>
+#include <linux/cache.h>
+#include <asm/syscall.h>
+
+/*
+ * Below you can see, in terms of #define's, the differences between the x86-64
+ * and the UML syscall table.
+ */
+
+/* Not going to be implemented by UML, since we have no hardware. */
+#define sys_iopl sys_ni_syscall
+#define sys_ioperm sys_ni_syscall
+
+#define __SYSCALL(nr, sym) extern asmlinkage long sym(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long);
+#include <asm/syscalls_64.h>
+
+#undef __SYSCALL
+#define __SYSCALL(nr, sym) sym,
+
+extern asmlinkage long sys_ni_syscall(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long);
+
+const sys_call_ptr_t sys_call_table[] ____cacheline_aligned = {
+#include <asm/syscalls_64.h>
+};
+
+int syscall_table_size = sizeof(sys_call_table);
diff --git a/arch/x86/um/syscalls_32.c b/arch/x86/um/syscalls_32.c
new file mode 100644
index 0000000000..5c65254c8f
--- /dev/null
+++ b/arch/x86/um/syscalls_32.c
@@ -0,0 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/syscalls.h>
+#include <os.h>
+
+SYSCALL_DEFINE2(arch_prctl, int, option, unsigned long, arg2)
+{
+	return -EINVAL;
+}
diff --git a/arch/x86/um/syscalls_64.c b/arch/x86/um/syscalls_64.c
new file mode 100644
index 0000000000..27b29ae6c4
--- /dev/null
+++ b/arch/x86/um/syscalls_64.c
@@ -0,0 +1,100 @@
+/*
+ * Copyright (C) 2003 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+ * Copyright 2003 PathScale, Inc.
+ *
+ * Licensed under the GPL
+ */
+
+#include <linux/sched.h>
+#include <linux/sched/mm.h>
+#include <linux/syscalls.h>
+#include <linux/uaccess.h>
+#include <asm/prctl.h> /* XXX This should get the constants from libc */
+#include <registers.h>
+#include <os.h>
+
+long arch_prctl(struct task_struct *task, int option,
+		unsigned long __user *arg2)
+{
+	unsigned long *ptr = arg2, tmp;
+	long ret;
+	int pid = task->mm->context.id.u.pid;
+
+	/*
+	 * With ARCH_SET_FS (and ARCH_SET_GS is treated similarly to
+	 * be safe), we need to call arch_prctl on the host because
+	 * setting %fs may result in something else happening (like a
+	 * GDT or thread.fs being set instead).  So, we let the host
+	 * fiddle the registers and thread struct and restore the
+	 * registers afterwards.
+	 *
+	 * So, the saved registers are stored to the process (this
+	 * needed because a stub may have been the last thing to run),
+	 * arch_prctl is run on the host, then the registers are read
+	 * back.
+	 */
+	switch (option) {
+	case ARCH_SET_FS:
+	case ARCH_SET_GS:
+		ret = restore_pid_registers(pid, &current->thread.regs.regs);
+		if (ret)
+			return ret;
+		break;
+	case ARCH_GET_FS:
+	case ARCH_GET_GS:
+		/*
+		 * With these two, we read to a local pointer and
+		 * put_user it to the userspace pointer that we were
+		 * given.  If addr isn't valid (because it hasn't been
+		 * faulted in or is just bogus), we want put_user to
+		 * fault it in (or return -EFAULT) instead of having
+		 * the host return -EFAULT.
+		 */
+		ptr = &tmp;
+	}
+
+	ret = os_arch_prctl(pid, option, ptr);
+	if (ret)
+		return ret;
+
+	switch (option) {
+	case ARCH_SET_FS:
+		current->thread.arch.fs = (unsigned long) ptr;
+		ret = save_registers(pid, &current->thread.regs.regs);
+		break;
+	case ARCH_SET_GS:
+		ret = save_registers(pid, &current->thread.regs.regs);
+		break;
+	case ARCH_GET_FS:
+		ret = put_user(tmp, arg2);
+		break;
+	case ARCH_GET_GS:
+		ret = put_user(tmp, arg2);
+		break;
+	}
+
+	return ret;
+}
+
+SYSCALL_DEFINE2(arch_prctl, int, option, unsigned long, arg2)
+{
+	return arch_prctl(current, option, (unsigned long __user *) arg2);
+}
+
+void arch_switch_to(struct task_struct *to)
+{
+	if ((to->thread.arch.fs == 0) || (to->mm == NULL))
+		return;
+
+	arch_prctl(to, ARCH_SET_FS, (void __user *) to->thread.arch.fs);
+}
+
+SYSCALL_DEFINE6(mmap, unsigned long, addr, unsigned long, len,
+		unsigned long, prot, unsigned long, flags,
+		unsigned long, fd, unsigned long, off)
+{
+	if (off & ~PAGE_MASK)
+		return -EINVAL;
+
+	return ksys_mmap_pgoff(addr, len, prot, flags, fd, off >> PAGE_SHIFT);
+}
diff --git a/arch/x86/um/sysrq_32.c b/arch/x86/um/sysrq_32.c
new file mode 100644
index 0000000000..f238348484
--- /dev/null
+++ b/arch/x86/um/sysrq_32.c
@@ -0,0 +1,34 @@
+/*
+ * Copyright (C) 2001 - 2003 Jeff Dike (jdike@addtoit.com)
+ * Licensed under the GPL
+ */
+
+#include <linux/kernel.h>
+#include <linux/smp.h>
+#include <linux/sched.h>
+#include <linux/sched/debug.h>
+#include <linux/kallsyms.h>
+#include <asm/ptrace.h>
+#include <asm/sysrq.h>
+
+/* This is declared by <linux/sched.h> */
+void show_regs(struct pt_regs *regs)
+{
+        printk("\n");
+        printk("EIP: %04lx:[<%08lx>] CPU: %d %s", 
+	       0xffff & PT_REGS_CS(regs), PT_REGS_IP(regs),
+	       smp_processor_id(), print_tainted());
+        if (PT_REGS_CS(regs) & 3)
+                printk(" ESP: %04lx:%08lx", 0xffff & PT_REGS_SS(regs),
+		       PT_REGS_SP(regs));
+        printk(" EFLAGS: %08lx\n    %s\n", PT_REGS_EFLAGS(regs),
+	       print_tainted());
+        printk("EAX: %08lx EBX: %08lx ECX: %08lx EDX: %08lx\n",
+               PT_REGS_AX(regs), PT_REGS_BX(regs), 
+	       PT_REGS_CX(regs), PT_REGS_DX(regs));
+        printk("ESI: %08lx EDI: %08lx EBP: %08lx",
+	       PT_REGS_SI(regs), PT_REGS_DI(regs), PT_REGS_BP(regs));
+        printk(" DS: %04lx ES: %04lx\n",
+	       0xffff & PT_REGS_DS(regs), 
+	       0xffff & PT_REGS_ES(regs));
+}
diff --git a/arch/x86/um/sysrq_64.c b/arch/x86/um/sysrq_64.c
new file mode 100644
index 0000000000..ef1eb4f4f6
--- /dev/null
+++ b/arch/x86/um/sysrq_64.c
@@ -0,0 +1,36 @@
+/*
+ * Copyright 2003 PathScale, Inc.
+ *
+ * Licensed under the GPL
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <linux/sched/debug.h>
+#include <linux/utsname.h>
+#include <asm/current.h>
+#include <asm/ptrace.h>
+#include <asm/sysrq.h>
+
+void show_regs(struct pt_regs *regs)
+{
+	printk("\n");
+	print_modules();
+	printk(KERN_INFO "Pid: %d, comm: %.20s %s %s\n", task_pid_nr(current),
+		current->comm, print_tainted(), init_utsname()->release);
+	printk(KERN_INFO "RIP: %04lx:%pS\n", PT_REGS_CS(regs) & 0xffff,
+	       (void *)PT_REGS_IP(regs));
+	printk(KERN_INFO "RSP: %016lx  EFLAGS: %08lx\n", PT_REGS_SP(regs),
+	       PT_REGS_EFLAGS(regs));
+	printk(KERN_INFO "RAX: %016lx RBX: %016lx RCX: %016lx\n",
+	       PT_REGS_AX(regs), PT_REGS_BX(regs), PT_REGS_CX(regs));
+	printk(KERN_INFO "RDX: %016lx RSI: %016lx RDI: %016lx\n",
+	       PT_REGS_DX(regs), PT_REGS_SI(regs), PT_REGS_DI(regs));
+	printk(KERN_INFO "RBP: %016lx R08: %016lx R09: %016lx\n",
+	       PT_REGS_BP(regs), PT_REGS_R8(regs), PT_REGS_R9(regs));
+	printk(KERN_INFO "R10: %016lx R11: %016lx R12: %016lx\n",
+	       PT_REGS_R10(regs), PT_REGS_R11(regs), PT_REGS_R12(regs));
+	printk(KERN_INFO "R13: %016lx R14: %016lx R15: %016lx\n",
+	       PT_REGS_R13(regs), PT_REGS_R14(regs), PT_REGS_R15(regs));
+}
diff --git a/arch/x86/um/tls_32.c b/arch/x86/um/tls_32.c
new file mode 100644
index 0000000000..66162eafd8
--- /dev/null
+++ b/arch/x86/um/tls_32.c
@@ -0,0 +1,390 @@
+/*
+ * Copyright (C) 2005 Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
+ * Licensed under the GPL
+ */
+
+#include <linux/percpu.h>
+#include <linux/sched.h>
+#include <linux/syscalls.h>
+#include <linux/uaccess.h>
+#include <asm/ptrace-abi.h>
+#include <os.h>
+#include <skas.h>
+#include <sysdep/tls.h>
+
+/*
+ * If needed we can detect when it's uninitialized.
+ *
+ * These are initialized in an initcall and unchanged thereafter.
+ */
+static int host_supports_tls = -1;
+int host_gdt_entry_tls_min;
+
+int do_set_thread_area(struct user_desc *info)
+{
+	int ret;
+	u32 cpu;
+
+	cpu = get_cpu();
+	ret = os_set_thread_area(info, userspace_pid[cpu]);
+	put_cpu();
+
+	if (ret)
+		printk(KERN_ERR "PTRACE_SET_THREAD_AREA failed, err = %d, "
+		       "index = %d\n", ret, info->entry_number);
+
+	return ret;
+}
+
+int do_get_thread_area(struct user_desc *info)
+{
+	int ret;
+	u32 cpu;
+
+	cpu = get_cpu();
+	ret = os_get_thread_area(info, userspace_pid[cpu]);
+	put_cpu();
+
+	if (ret)
+		printk(KERN_ERR "PTRACE_GET_THREAD_AREA failed, err = %d, "
+		       "index = %d\n", ret, info->entry_number);
+
+	return ret;
+}
+
+/*
+ * sys_get_thread_area: get a yet unused TLS descriptor index.
+ * XXX: Consider leaving one free slot for glibc usage at first place. This must
+ * be done here (and by changing GDT_ENTRY_TLS_* macros) and nowhere else.
+ *
+ * Also, this must be tested when compiling in SKAS mode with dynamic linking
+ * and running against NPTL.
+ */
+static int get_free_idx(struct task_struct* task)
+{
+	struct thread_struct *t = &task->thread;
+	int idx;
+
+	for (idx = 0; idx < GDT_ENTRY_TLS_ENTRIES; idx++)
+		if (!t->arch.tls_array[idx].present)
+			return idx + GDT_ENTRY_TLS_MIN;
+	return -ESRCH;
+}
+
+static inline void clear_user_desc(struct user_desc* info)
+{
+	/* Postcondition: LDT_empty(info) returns true. */
+	memset(info, 0, sizeof(*info));
+
+	/*
+	 * Check the LDT_empty or the i386 sys_get_thread_area code - we obtain
+	 * indeed an empty user_desc.
+	 */
+	info->read_exec_only = 1;
+	info->seg_not_present = 1;
+}
+
+#define O_FORCE 1
+
+static int load_TLS(int flags, struct task_struct *to)
+{
+	int ret = 0;
+	int idx;
+
+	for (idx = GDT_ENTRY_TLS_MIN; idx < GDT_ENTRY_TLS_MAX; idx++) {
+		struct uml_tls_struct* curr =
+			&to->thread.arch.tls_array[idx - GDT_ENTRY_TLS_MIN];
+
+		/*
+		 * Actually, now if it wasn't flushed it gets cleared and
+		 * flushed to the host, which will clear it.
+		 */
+		if (!curr->present) {
+			if (!curr->flushed) {
+				clear_user_desc(&curr->tls);
+				curr->tls.entry_number = idx;
+			} else {
+				WARN_ON(!LDT_empty(&curr->tls));
+				continue;
+			}
+		}
+
+		if (!(flags & O_FORCE) && curr->flushed)
+			continue;
+
+		ret = do_set_thread_area(&curr->tls);
+		if (ret)
+			goto out;
+
+		curr->flushed = 1;
+	}
+out:
+	return ret;
+}
+
+/*
+ * Verify if we need to do a flush for the new process, i.e. if there are any
+ * present desc's, only if they haven't been flushed.
+ */
+static inline int needs_TLS_update(struct task_struct *task)
+{
+	int i;
+	int ret = 0;
+
+	for (i = GDT_ENTRY_TLS_MIN; i < GDT_ENTRY_TLS_MAX; i++) {
+		struct uml_tls_struct* curr =
+			&task->thread.arch.tls_array[i - GDT_ENTRY_TLS_MIN];
+
+		/*
+		 * Can't test curr->present, we may need to clear a descriptor
+		 * which had a value.
+		 */
+		if (curr->flushed)
+			continue;
+		ret = 1;
+		break;
+	}
+	return ret;
+}
+
+/*
+ * On a newly forked process, the TLS descriptors haven't yet been flushed. So
+ * we mark them as such and the first switch_to will do the job.
+ */
+void clear_flushed_tls(struct task_struct *task)
+{
+	int i;
+
+	for (i = GDT_ENTRY_TLS_MIN; i < GDT_ENTRY_TLS_MAX; i++) {
+		struct uml_tls_struct* curr =
+			&task->thread.arch.tls_array[i - GDT_ENTRY_TLS_MIN];
+
+		/*
+		 * Still correct to do this, if it wasn't present on the host it
+		 * will remain as flushed as it was.
+		 */
+		if (!curr->present)
+			continue;
+
+		curr->flushed = 0;
+	}
+}
+
+/*
+ * In SKAS0 mode, currently, multiple guest threads sharing the same ->mm have a
+ * common host process. So this is needed in SKAS0 too.
+ *
+ * However, if each thread had a different host process (and this was discussed
+ * for SMP support) this won't be needed.
+ *
+ * And this will not need be used when (and if) we'll add support to the host
+ * SKAS patch.
+ */
+
+int arch_switch_tls(struct task_struct *to)
+{
+	if (!host_supports_tls)
+		return 0;
+
+	/*
+	 * We have no need whatsoever to switch TLS for kernel threads; beyond
+	 * that, that would also result in us calling os_set_thread_area with
+	 * userspace_pid[cpu] == 0, which gives an error.
+	 */
+	if (likely(to->mm))
+		return load_TLS(O_FORCE, to);
+
+	return 0;
+}
+
+static int set_tls_entry(struct task_struct* task, struct user_desc *info,
+			 int idx, int flushed)
+{
+	struct thread_struct *t = &task->thread;
+
+	if (idx < GDT_ENTRY_TLS_MIN || idx > GDT_ENTRY_TLS_MAX)
+		return -EINVAL;
+
+	t->arch.tls_array[idx - GDT_ENTRY_TLS_MIN].tls = *info;
+	t->arch.tls_array[idx - GDT_ENTRY_TLS_MIN].present = 1;
+	t->arch.tls_array[idx - GDT_ENTRY_TLS_MIN].flushed = flushed;
+
+	return 0;
+}
+
+int arch_set_tls(struct task_struct *new, unsigned long tls)
+{
+	struct user_desc info;
+	int idx, ret = -EFAULT;
+
+	if (copy_from_user(&info, (void __user *) tls, sizeof(info)))
+		goto out;
+
+	ret = -EINVAL;
+	if (LDT_empty(&info))
+		goto out;
+
+	idx = info.entry_number;
+
+	ret = set_tls_entry(new, &info, idx, 0);
+out:
+	return ret;
+}
+
+/* XXX: use do_get_thread_area to read the host value? I'm not at all sure! */
+static int get_tls_entry(struct task_struct *task, struct user_desc *info,
+			 int idx)
+{
+	struct thread_struct *t = &task->thread;
+
+	if (idx < GDT_ENTRY_TLS_MIN || idx > GDT_ENTRY_TLS_MAX)
+		return -EINVAL;
+
+	if (!t->arch.tls_array[idx - GDT_ENTRY_TLS_MIN].present)
+		goto clear;
+
+	*info = t->arch.tls_array[idx - GDT_ENTRY_TLS_MIN].tls;
+
+out:
+	/*
+	 * Temporary debugging check, to make sure that things have been
+	 * flushed. This could be triggered if load_TLS() failed.
+	 */
+	if (unlikely(task == current &&
+		     !t->arch.tls_array[idx - GDT_ENTRY_TLS_MIN].flushed)) {
+		printk(KERN_ERR "get_tls_entry: task with pid %d got here "
+				"without flushed TLS.", current->pid);
+	}
+
+	return 0;
+clear:
+	/*
+	 * When the TLS entry has not been set, the values read to user in the
+	 * tls_array are 0 (because it's cleared at boot, see
+	 * arch/i386/kernel/head.S:cpu_gdt_table). Emulate that.
+	 */
+	clear_user_desc(info);
+	info->entry_number = idx;
+	goto out;
+}
+
+SYSCALL_DEFINE1(set_thread_area, struct user_desc __user *, user_desc)
+{
+	struct user_desc info;
+	int idx, ret;
+
+	if (!host_supports_tls)
+		return -ENOSYS;
+
+	if (copy_from_user(&info, user_desc, sizeof(info)))
+		return -EFAULT;
+
+	idx = info.entry_number;
+
+	if (idx == -1) {
+		idx = get_free_idx(current);
+		if (idx < 0)
+			return idx;
+		info.entry_number = idx;
+		/* Tell the user which slot we chose for him.*/
+		if (put_user(idx, &user_desc->entry_number))
+			return -EFAULT;
+	}
+
+	ret = do_set_thread_area(&info);
+	if (ret)
+		return ret;
+	return set_tls_entry(current, &info, idx, 1);
+}
+
+/*
+ * Perform set_thread_area on behalf of the traced child.
+ * Note: error handling is not done on the deferred load, and this differ from
+ * i386. However the only possible error are caused by bugs.
+ */
+int ptrace_set_thread_area(struct task_struct *child, int idx,
+			   struct user_desc __user *user_desc)
+{
+	struct user_desc info;
+
+	if (!host_supports_tls)
+		return -EIO;
+
+	if (copy_from_user(&info, user_desc, sizeof(info)))
+		return -EFAULT;
+
+	return set_tls_entry(child, &info, idx, 0);
+}
+
+SYSCALL_DEFINE1(get_thread_area, struct user_desc __user *, user_desc)
+{
+	struct user_desc info;
+	int idx, ret;
+
+	if (!host_supports_tls)
+		return -ENOSYS;
+
+	if (get_user(idx, &user_desc->entry_number))
+		return -EFAULT;
+
+	ret = get_tls_entry(current, &info, idx);
+	if (ret < 0)
+		goto out;
+
+	if (copy_to_user(user_desc, &info, sizeof(info)))
+		ret = -EFAULT;
+
+out:
+	return ret;
+}
+
+/*
+ * Perform get_thread_area on behalf of the traced child.
+ */
+int ptrace_get_thread_area(struct task_struct *child, int idx,
+		struct user_desc __user *user_desc)
+{
+	struct user_desc info;
+	int ret;
+
+	if (!host_supports_tls)
+		return -EIO;
+
+	ret = get_tls_entry(child, &info, idx);
+	if (ret < 0)
+		goto out;
+
+	if (copy_to_user(user_desc, &info, sizeof(info)))
+		ret = -EFAULT;
+out:
+	return ret;
+}
+
+/*
+ * This code is really i386-only, but it detects and logs x86_64 GDT indexes
+ * if a 32-bit UML is running on a 64-bit host.
+ */
+static int __init __setup_host_supports_tls(void)
+{
+	check_host_supports_tls(&host_supports_tls, &host_gdt_entry_tls_min);
+	if (host_supports_tls) {
+		printk(KERN_INFO "Host TLS support detected\n");
+		printk(KERN_INFO "Detected host type: ");
+		switch (host_gdt_entry_tls_min) {
+		case GDT_ENTRY_TLS_MIN_I386:
+			printk(KERN_CONT "i386");
+			break;
+		case GDT_ENTRY_TLS_MIN_X86_64:
+			printk(KERN_CONT "x86_64");
+			break;
+		}
+		printk(KERN_CONT " (GDT indexes %d to %d)\n",
+		       host_gdt_entry_tls_min,
+		       host_gdt_entry_tls_min + GDT_ENTRY_TLS_ENTRIES);
+	} else
+		printk(KERN_ERR "  Host TLS support NOT detected! "
+				"TLS support inside UML will not work\n");
+	return 0;
+}
+
+__initcall(__setup_host_supports_tls);
diff --git a/arch/x86/um/tls_64.c b/arch/x86/um/tls_64.c
new file mode 100644
index 0000000000..ebd3855d9b
--- /dev/null
+++ b/arch/x86/um/tls_64.c
@@ -0,0 +1,18 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/sched.h>
+#include <asm/ptrace-abi.h>
+
+void clear_flushed_tls(struct task_struct *task)
+{
+}
+
+int arch_set_tls(struct task_struct *t, unsigned long tls)
+{
+	/*
+	 * If CLONE_SETTLS is set, we need to save the thread id
+	 * so it can be set during context switches.
+	 */
+	t->thread.arch.fs = tls;
+
+	return 0;
+}
diff --git a/arch/x86/um/user-offsets.c b/arch/x86/um/user-offsets.c
new file mode 100644
index 0000000000..e54a9814cc
--- /dev/null
+++ b/arch/x86/um/user-offsets.c
@@ -0,0 +1,84 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <stdio.h>
+#include <stddef.h>
+#include <signal.h>
+#include <poll.h>
+#include <sys/mman.h>
+#include <sys/user.h>
+#define __FRAME_OFFSETS
+#include <linux/ptrace.h>
+#include <asm/types.h>
+#include <linux/kbuild.h>
+
+#define DEFINE_LONGS(sym, val)	\
+	COMMENT(#val " / sizeof(unsigned long)");	\
+	DEFINE(sym, val / sizeof(unsigned long))
+
+void foo(void)
+{
+#ifdef __i386__
+	DEFINE_LONGS(HOST_FP_SIZE, sizeof(struct user_fpregs_struct));
+	DEFINE_LONGS(HOST_FPX_SIZE, sizeof(struct user_fpxregs_struct));
+
+	DEFINE(HOST_IP, EIP);
+	DEFINE(HOST_SP, UESP);
+	DEFINE(HOST_EFLAGS, EFL);
+	DEFINE(HOST_AX, EAX);
+	DEFINE(HOST_BX, EBX);
+	DEFINE(HOST_CX, ECX);
+	DEFINE(HOST_DX, EDX);
+	DEFINE(HOST_SI, ESI);
+	DEFINE(HOST_DI, EDI);
+	DEFINE(HOST_BP, EBP);
+	DEFINE(HOST_CS, CS);
+	DEFINE(HOST_SS, SS);
+	DEFINE(HOST_DS, DS);
+	DEFINE(HOST_FS, FS);
+	DEFINE(HOST_ES, ES);
+	DEFINE(HOST_GS, GS);
+	DEFINE(HOST_ORIG_AX, ORIG_EAX);
+#else
+#ifdef FP_XSTATE_MAGIC1
+	DEFINE_LONGS(HOST_FP_SIZE, 2696);
+#else
+	DEFINE(HOST_FP_SIZE, sizeof(struct _fpstate) / sizeof(unsigned long));
+#endif
+	DEFINE_LONGS(HOST_BX, RBX);
+	DEFINE_LONGS(HOST_CX, RCX);
+	DEFINE_LONGS(HOST_DI, RDI);
+	DEFINE_LONGS(HOST_SI, RSI);
+	DEFINE_LONGS(HOST_DX, RDX);
+	DEFINE_LONGS(HOST_BP, RBP);
+	DEFINE_LONGS(HOST_AX, RAX);
+	DEFINE_LONGS(HOST_R8, R8);
+	DEFINE_LONGS(HOST_R9, R9);
+	DEFINE_LONGS(HOST_R10, R10);
+	DEFINE_LONGS(HOST_R11, R11);
+	DEFINE_LONGS(HOST_R12, R12);
+	DEFINE_LONGS(HOST_R13, R13);
+	DEFINE_LONGS(HOST_R14, R14);
+	DEFINE_LONGS(HOST_R15, R15);
+	DEFINE_LONGS(HOST_ORIG_AX, ORIG_RAX);
+	DEFINE_LONGS(HOST_CS, CS);
+	DEFINE_LONGS(HOST_SS, SS);
+	DEFINE_LONGS(HOST_EFLAGS, EFLAGS);
+#if 0
+	DEFINE_LONGS(HOST_FS, FS);
+	DEFINE_LONGS(HOST_GS, GS);
+	DEFINE_LONGS(HOST_DS, DS);
+	DEFINE_LONGS(HOST_ES, ES);
+#endif
+
+	DEFINE_LONGS(HOST_IP, RIP);
+	DEFINE_LONGS(HOST_SP, RSP);
+#endif
+
+	DEFINE(UM_FRAME_SIZE, sizeof(struct user_regs_struct));
+	DEFINE(UM_POLLIN, POLLIN);
+	DEFINE(UM_POLLPRI, POLLPRI);
+	DEFINE(UM_POLLOUT, POLLOUT);
+
+	DEFINE(UM_PROT_READ, PROT_READ);
+	DEFINE(UM_PROT_WRITE, PROT_WRITE);
+	DEFINE(UM_PROT_EXEC, PROT_EXEC);
+}
diff --git a/arch/x86/um/vdso/.gitignore b/arch/x86/um/vdso/.gitignore
new file mode 100644
index 0000000000..652e31d825
--- /dev/null
+++ b/arch/x86/um/vdso/.gitignore
@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0-only
+vdso.lds
diff --git a/arch/x86/um/vdso/Makefile b/arch/x86/um/vdso/Makefile
new file mode 100644
index 0000000000..6825e146a6
--- /dev/null
+++ b/arch/x86/um/vdso/Makefile
@@ -0,0 +1,81 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Building vDSO images for x86.
+#
+
+# do not instrument on vdso because KASAN is not compatible with user mode
+KASAN_SANITIZE			:= n
+
+# Prevents link failures: __sanitizer_cov_trace_pc() is not linked in.
+KCOV_INSTRUMENT                := n
+
+VDSO64-y		:= y
+
+vdso-install-$(VDSO64-y)	+= vdso.so
+
+
+# files to link into the vdso
+vobjs-y := vdso-note.o um_vdso.o
+
+# files to link into kernel
+obj-$(VDSO64-y)			+= vdso.o vma.o
+
+vobjs := $(foreach F,$(vobjs-y),$(obj)/$F)
+
+$(obj)/vdso.o: $(obj)/vdso.so
+
+targets += vdso.so vdso.so.dbg vdso.lds $(vobjs-y)
+
+CPPFLAGS_vdso.lds += -P -C
+
+VDSO_LDFLAGS_vdso.lds = -m64 -Wl,-soname=linux-vdso.so.1 \
+       -Wl,-z,max-page-size=4096
+
+$(obj)/vdso.o: $(src)/vdso.S $(obj)/vdso.so
+
+$(obj)/vdso.so.dbg: $(obj)/vdso.lds $(vobjs) FORCE
+	$(call if_changed,vdso)
+
+$(obj)/%.so: OBJCOPYFLAGS := -S
+$(obj)/%.so: $(obj)/%.so.dbg FORCE
+	$(call if_changed,objcopy)
+
+#
+# Don't omit frame pointers for ease of userspace debugging, but do
+# optimize sibling calls.
+#
+CFL := $(PROFILING) -mcmodel=small -fPIC -O2 -fasynchronous-unwind-tables -m64 \
+       $(filter -g%,$(KBUILD_CFLAGS)) -fno-stack-protector \
+       -fno-omit-frame-pointer -foptimize-sibling-calls
+
+$(vobjs): KBUILD_CFLAGS += $(CFL)
+
+#
+# vDSO code runs in userspace and -pg doesn't help with profiling anyway.
+#
+CFLAGS_REMOVE_vdso-note.o = -pg -fprofile-arcs -ftest-coverage
+CFLAGS_REMOVE_um_vdso.o = -pg -fprofile-arcs -ftest-coverage
+
+#
+# The DSO images are built using a special linker script.
+#
+quiet_cmd_vdso = VDSO    $@
+      cmd_vdso = $(CC) -nostdlib -o $@ \
+		       $(CC_FLAGS_LTO) $(VDSO_LDFLAGS) $(VDSO_LDFLAGS_$(filter %.lds,$(^F))) \
+		       -Wl,-T,$(filter %.lds,$^) $(filter %.o,$^) && \
+		 sh $(srctree)/$(src)/checkundef.sh '$(NM)' '$@'
+
+VDSO_LDFLAGS = -fPIC -shared -Wl,--hash-style=sysv -z noexecstack
+GCOV_PROFILE := n
+
+#
+# Install the unstripped copy of vdso*.so listed in $(vdso-install-y).
+#
+quiet_cmd_vdso_install = INSTALL $@
+      cmd_vdso_install = cp $(obj)/$@.dbg $(MODLIB)/vdso/$@
+$(vdso-install-y): %.so: $(obj)/%.so.dbg FORCE
+	@mkdir -p $(MODLIB)/vdso
+	$(call cmd,vdso_install)
+
+PHONY += vdso_install $(vdso-install-y)
+vdso_install: $(vdso-install-y)
diff --git a/arch/x86/um/vdso/checkundef.sh b/arch/x86/um/vdso/checkundef.sh
new file mode 100644
index 0000000000..8e3ea6bb95
--- /dev/null
+++ b/arch/x86/um/vdso/checkundef.sh
@@ -0,0 +1,11 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
+nm="$1"
+file="$2"
+$nm "$file" | grep '^ *U' > /dev/null 2>&1
+if [ $? -eq 1 ]; then
+    exit 0
+else
+    echo "$file: undefined symbols found" >&2
+    exit 1
+fi
diff --git a/arch/x86/um/vdso/um_vdso.c b/arch/x86/um/vdso/um_vdso.c
new file mode 100644
index 0000000000..ff0f3b4b6c
--- /dev/null
+++ b/arch/x86/um/vdso/um_vdso.c
@@ -0,0 +1,72 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2011 Richard Weinberger <richrd@nod.at>
+ *
+ * This vDSO turns all calls into a syscall so that UML can trap them.
+ */
+
+
+/* Disable profiling for userspace code */
+#define DISABLE_BRANCH_PROFILING
+
+#include <linux/time.h>
+#include <linux/getcpu.h>
+#include <asm/unistd.h>
+
+int __vdso_clock_gettime(clockid_t clock, struct __kernel_old_timespec *ts)
+{
+	long ret;
+
+	asm("syscall"
+		: "=a" (ret)
+		: "0" (__NR_clock_gettime), "D" (clock), "S" (ts)
+		: "rcx", "r11", "memory");
+
+	return ret;
+}
+int clock_gettime(clockid_t, struct __kernel_old_timespec *)
+	__attribute__((weak, alias("__vdso_clock_gettime")));
+
+int __vdso_gettimeofday(struct __kernel_old_timeval *tv, struct timezone *tz)
+{
+	long ret;
+
+	asm("syscall"
+		: "=a" (ret)
+		: "0" (__NR_gettimeofday), "D" (tv), "S" (tz)
+		: "rcx", "r11", "memory");
+
+	return ret;
+}
+int gettimeofday(struct __kernel_old_timeval *, struct timezone *)
+	__attribute__((weak, alias("__vdso_gettimeofday")));
+
+__kernel_old_time_t __vdso_time(__kernel_old_time_t *t)
+{
+	long secs;
+
+	asm volatile("syscall"
+		: "=a" (secs)
+		: "0" (__NR_time), "D" (t) : "cc", "r11", "cx", "memory");
+
+	return secs;
+}
+__kernel_old_time_t time(__kernel_old_time_t *t) __attribute__((weak, alias("__vdso_time")));
+
+long
+__vdso_getcpu(unsigned *cpu, unsigned *node, struct getcpu_cache *unused)
+{
+	/*
+	 * UML does not support SMP, we can cheat here. :)
+	 */
+
+	if (cpu)
+		*cpu = 0;
+	if (node)
+		*node = 0;
+
+	return 0;
+}
+
+long getcpu(unsigned *cpu, unsigned *node, struct getcpu_cache *tcache)
+	__attribute__((weak, alias("__vdso_getcpu")));
diff --git a/arch/x86/um/vdso/vdso-layout.lds.S b/arch/x86/um/vdso/vdso-layout.lds.S
new file mode 100644
index 0000000000..439b790df1
--- /dev/null
+++ b/arch/x86/um/vdso/vdso-layout.lds.S
@@ -0,0 +1,65 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Linker script for vDSO.  This is an ELF shared object prelinked to
+ * its virtual address, and with only one read-only segment.
+ * This script controls its layout.
+ */
+
+SECTIONS
+{
+	. = VDSO_PRELINK + SIZEOF_HEADERS;
+
+	.hash		: { *(.hash) }			:text
+	.gnu.hash	: { *(.gnu.hash) }
+	.dynsym		: { *(.dynsym) }
+	.dynstr		: { *(.dynstr) }
+	.gnu.version	: { *(.gnu.version) }
+	.gnu.version_d	: { *(.gnu.version_d) }
+	.gnu.version_r	: { *(.gnu.version_r) }
+
+	.note		: { *(.note.*) }		:text	:note
+
+	.eh_frame_hdr	: { *(.eh_frame_hdr) }		:text	:eh_frame_hdr
+	.eh_frame	: { KEEP (*(.eh_frame)) }	:text
+
+	.dynamic	: { *(.dynamic) }		:text	:dynamic
+
+	.rodata		: { *(.rodata*) }		:text
+	.data		: {
+	      *(.data*)
+	      *(.sdata*)
+	      *(.got.plt) *(.got)
+	      *(.gnu.linkonce.d.*)
+	      *(.bss*)
+	      *(.dynbss*)
+	      *(.gnu.linkonce.b.*)
+	}
+
+	.altinstructions	: { *(.altinstructions) }
+	.altinstr_replacement	: { *(.altinstr_replacement) }
+
+	/*
+	 * Align the actual code well away from the non-instruction data.
+	 * This is the best thing for the I-cache.
+	 */
+	. = ALIGN(0x100);
+
+	.text		: { *(.text*) }			:text	=0x90909090
+}
+
+/*
+ * Very old versions of ld do not recognize this name token; use the constant.
+ */
+#define PT_GNU_EH_FRAME	0x6474e550
+
+/*
+ * We must supply the ELF program headers explicitly to get just one
+ * PT_LOAD segment, and set the flags explicitly to make segments read-only.
+ */
+PHDRS
+{
+	text		PT_LOAD		FLAGS(5) FILEHDR PHDRS; /* PF_R|PF_X */
+	dynamic		PT_DYNAMIC	FLAGS(4);		/* PF_R */
+	note		PT_NOTE		FLAGS(4);		/* PF_R */
+	eh_frame_hdr	PT_GNU_EH_FRAME;
+}
diff --git a/arch/x86/um/vdso/vdso-note.S b/arch/x86/um/vdso/vdso-note.S
new file mode 100644
index 0000000000..79a071e435
--- /dev/null
+++ b/arch/x86/um/vdso/vdso-note.S
@@ -0,0 +1,12 @@
+/*
+ * This supplies .note.* sections to go into the PT_NOTE inside the vDSO text.
+ * Here we can supply some information useful to userland.
+ */
+
+#include <linux/uts.h>
+#include <linux/version.h>
+#include <linux/elfnote.h>
+
+ELFNOTE_START(Linux, 0, "a")
+	.long LINUX_VERSION_CODE
+ELFNOTE_END
diff --git a/arch/x86/um/vdso/vdso.S b/arch/x86/um/vdso/vdso.S
new file mode 100644
index 0000000000..a6eaf293a7
--- /dev/null
+++ b/arch/x86/um/vdso/vdso.S
@@ -0,0 +1,11 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#include <linux/init.h>
+#include <linux/linkage.h>
+
+__INITDATA
+
+SYM_DATA_START(vdso_start)
+	.incbin "arch/x86/um/vdso/vdso.so"
+SYM_DATA_END_LABEL(vdso_start, SYM_L_GLOBAL, vdso_end)
+
+__FINIT
diff --git a/arch/x86/um/vdso/vdso.lds.S b/arch/x86/um/vdso/vdso.lds.S
new file mode 100644
index 0000000000..73c508587a
--- /dev/null
+++ b/arch/x86/um/vdso/vdso.lds.S
@@ -0,0 +1,33 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Linker script for 64-bit vDSO.
+ * We #include the file to define the layout details.
+ * Here we only choose the prelinked virtual address.
+ *
+ * This file defines the version script giving the user-exported symbols in
+ * the DSO.  We can define local symbols here called VDSO* to make their
+ * values visible using the asm-x86/vdso.h macros from the kernel proper.
+ */
+
+#define VDSO_PRELINK 0xffffffffff700000
+#include "vdso-layout.lds.S"
+
+/*
+ * This controls what userland symbols we export from the vDSO.
+ */
+VERSION {
+	LINUX_2.6 {
+	global:
+		clock_gettime;
+		__vdso_clock_gettime;
+		gettimeofday;
+		__vdso_gettimeofday;
+		getcpu;
+		__vdso_getcpu;
+		time;
+		__vdso_time;
+	local: *;
+	};
+}
+
+VDSO64_PRELINK = VDSO_PRELINK;
diff --git a/arch/x86/um/vdso/vma.c b/arch/x86/um/vdso/vma.c
new file mode 100644
index 0000000000..76d9f6ce7a
--- /dev/null
+++ b/arch/x86/um/vdso/vma.c
@@ -0,0 +1,72 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2011 Richard Weinberger <richrd@nod.at>
+ */
+
+#include <linux/slab.h>
+#include <linux/sched.h>
+#include <linux/mm.h>
+#include <asm/page.h>
+#include <asm/elf.h>
+#include <linux/init.h>
+
+static unsigned int __read_mostly vdso_enabled = 1;
+unsigned long um_vdso_addr;
+
+extern unsigned long task_size;
+extern char vdso_start[], vdso_end[];
+
+static struct page **vdsop;
+
+static int __init init_vdso(void)
+{
+	struct page *um_vdso;
+
+	BUG_ON(vdso_end - vdso_start > PAGE_SIZE);
+
+	um_vdso_addr = task_size - PAGE_SIZE;
+
+	vdsop = kmalloc(sizeof(struct page *), GFP_KERNEL);
+	if (!vdsop)
+		goto oom;
+
+	um_vdso = alloc_page(GFP_KERNEL);
+	if (!um_vdso) {
+		kfree(vdsop);
+
+		goto oom;
+	}
+
+	copy_page(page_address(um_vdso), vdso_start);
+	*vdsop = um_vdso;
+
+	return 0;
+
+oom:
+	printk(KERN_ERR "Cannot allocate vdso\n");
+	vdso_enabled = 0;
+
+	return -ENOMEM;
+}
+subsys_initcall(init_vdso);
+
+int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
+{
+	int err;
+	struct mm_struct *mm = current->mm;
+
+	if (!vdso_enabled)
+		return 0;
+
+	if (mmap_write_lock_killable(mm))
+		return -EINTR;
+
+	err = install_special_mapping(mm, um_vdso_addr, PAGE_SIZE,
+		VM_READ|VM_EXEC|
+		VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC,
+		vdsop);
+
+	mmap_write_unlock(mm);
+
+	return err;
+}