Merge tag 'io_uring-7.3-20261002' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linuxgrafted

Pull io_uring fixes from Jens Axboe:

 - Fix a task_work add use-after-free with SQPOLL.

   The sqpoll thread could pop and complete the last request while
   io_req_normal_work_add() was still looking at them after the mpscq
   push.

   Use the same approach as DEFER_TASKRUN to protect from that, holding
   an RCU read lock across the add, and have exit wait for an RCU grace
   period for SQPOLL rings as well.

 - CQE32 ring fixes: correct the free entry check for 32b CQEs, zero the
   big_cqe for aux CQEs, and only post the dummy skip CQE on CQE_MIXED
   rings

 - Mark the source filter table as COW when cloning bpf filters, so
   registering another filter on the source doesn't modify the shared
   table in place

 - Initialize the task context before running the BPF loop

 - Requeue zcrx multishot receives stopped by a local resource

 - End a TX_TIMESTAMP multishot cmd when the CQ is full (lollipopkit)

* tag 'io_uring-7.3-20261002' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux:
  io_uring: fix task_work add use-after-free with SQPOLL
  io_uring/cmd_net: end TX_TIMESTAMP multishot when the CQ is full
  io_uring/zcrx: requeue multishot receives stopped by a local resource
  io_uring: initialize task context before running the BPF loop
  io_uring: zero big_cqe for aux CQEs on CQE32 rings
  io_uring: fix free entry check for 32b CQEs on CQE32 rings
  io_uring: only post the dummy skip CQE on CQE_MIXED rings
  io_uring/bpf_filter: mark source as COW when cloning filters

43 files changed, 1835 insertions, 0 deletions

diff --git a/arch/um/include/asm/Kbuild b/arch/um/include/asm/Kbuild
new file mode 100644
index 000000000..8fdc0bd9a
--- /dev/null
+++ b/arch/um/include/asm/Kbuild
@@ -0,0 +1,30 @@
+# SPDX-License-Identifier: GPL-2.0
+generic-y += bug.h
+generic-y += compat.h
+generic-y += device.h
+generic-y += dma-mapping.h
+generic-y += emergency-restart.h
+generic-y += exec.h
+generic-y += ftrace.h
+generic-y += hw_irq.h
+generic-y += irq_regs.h
+generic-y += irq_work.h
+generic-y += kdebug.h
+generic-y += mcs_spinlock.h
+generic-y += mmiowb.h
+generic-y += module.h
+generic-y += module.lds.h
+generic-y += parport.h
+generic-y += percpu.h
+generic-y += percpu_types.h
+generic-y += preempt.h
+generic-y += ring_buffer.h
+generic-y += runtime-const.h
+generic-y += softirq_stack.h
+generic-y += switch_to.h
+generic-y += topology.h
+generic-y += trace_clock.h
+generic-y += kprobes.h
+generic-y += mm_hooks.h
+generic-y += vga.h
+generic-y += video.h
diff --git a/arch/um/include/asm/archrandom.h b/arch/um/include/asm/archrandom.h
new file mode 100644
index 000000000..24e16c979
--- /dev/null
+++ b/arch/um/include/asm/archrandom.h
@@ -0,0 +1,25 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __ASM_UM_ARCHRANDOM_H__
+#define __ASM_UM_ARCHRANDOM_H__
+
+#include <linux/types.h>
+
+/* This is from <os.h>, but better not to #include that in a global header here. */
+ssize_t os_getrandom(void *buf, size_t len, unsigned int flags);
+
+static inline size_t __must_check arch_get_random_longs(unsigned long *v, size_t max_longs)
+{
+	ssize_t ret;
+
+	ret = os_getrandom(v, max_longs * sizeof(*v), 0);
+	if (ret < 0)
+		return 0;
+	return ret / sizeof(*v);
+}
+
+static inline size_t __must_check arch_get_random_seed_longs(unsigned long *v, size_t max_longs)
+{
+	return 0;
+}
+
+#endif
diff --git a/arch/um/include/asm/asm-prototypes.h b/arch/um/include/asm/asm-prototypes.h
new file mode 100644
index 000000000..408b31d59
--- /dev/null
+++ b/arch/um/include/asm/asm-prototypes.h
@@ -0,0 +1,6 @@
+#include <asm-generic/asm-prototypes.h>
+#include <asm/checksum.h>
+
+#ifdef CONFIG_UML_X86
+extern void cmpxchg8b_emu(void);
+#endif
diff --git a/arch/um/include/asm/bpf_perf_event.h b/arch/um/include/asm/bpf_perf_event.h
new file mode 100644
index 000000000..287221342
--- /dev/null
+++ b/arch/um/include/asm/bpf_perf_event.h
@@ -0,0 +1,9 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+/*
+ * asm-generic/bpf_perf_event.h is part of the uapi headers, but since
+ * arch/um has no uapi of its on, we can't use the "generic-y"
+ * Kbuild rule to generate the wrapper
+ */
+
+#include <asm-generic/bpf_perf_event.h>
diff --git a/arch/um/include/asm/cache.h b/arch/um/include/asm/cache.h
new file mode 100644
index 000000000..5c1562734
--- /dev/null
+++ b/arch/um/include/asm/cache.h
@@ -0,0 +1,18 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __UM_CACHE_H
+#define __UM_CACHE_H
+
+
+#if defined(CONFIG_UML_X86) && !defined(CONFIG_64BIT)
+# define L1_CACHE_SHIFT		(CONFIG_X86_L1_CACHE_SHIFT)
+#elif defined(CONFIG_UML_X86) /* 64-bit */
+# define L1_CACHE_SHIFT		6 /* Should be 7 on Intel */
+#else
+/* XXX: this was taken from x86, now it's completely random. Luckily only
+ * affects SMP padding. */
+# define L1_CACHE_SHIFT		5
+#endif
+
+#define L1_CACHE_BYTES		(1 << L1_CACHE_SHIFT)
+
+#endif
diff --git a/arch/um/include/asm/cacheflush.h b/arch/um/include/asm/cacheflush.h
new file mode 100644
index 000000000..4c9858cd3
--- /dev/null
+++ b/arch/um/include/asm/cacheflush.h
@@ -0,0 +1,9 @@
+#ifndef __UM_ASM_CACHEFLUSH_H
+#define __UM_ASM_CACHEFLUSH_H
+
+#include <asm/tlbflush.h>
+#define flush_cache_vmap flush_tlb_kernel_range
+#define flush_cache_vunmap flush_tlb_kernel_range
+
+#include <asm-generic/cacheflush.h>
+#endif /* __UM_ASM_CACHEFLUSH_H */
diff --git a/arch/um/include/asm/common.lds.S b/arch/um/include/asm/common.lds.S
new file mode 100644
index 000000000..fd481ac37
--- /dev/null
+++ b/arch/um/include/asm/common.lds.S
@@ -0,0 +1,101 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#include <asm-generic/vmlinux.lds.h>
+
+  .fini      : { *(.fini)    } =0x9090
+  _etext = .;
+  PROVIDE (etext = .);
+
+  . = ALIGN(4096);
+  _sdata = .;
+  PROVIDE (sdata = .);
+
+  RO_DATA(4096)
+
+  .unprotected : { *(.unprotected) }
+  . = ALIGN(4096);
+  PROVIDE (_unprotected_end = .);
+
+  . = ALIGN(4096);
+  EXCEPTION_TABLE(0)
+
+  BUG_TABLE
+
+  .uml.setup.init : {
+	__uml_setup_start = .;
+	*(.uml.setup.init)
+	__uml_setup_end = .;
+  }
+	
+  .uml.help.init : {
+	__uml_help_start = .;
+	*(.uml.help.init)
+	__uml_help_end = .;
+  }
+	
+  .uml.postsetup.init : {
+	__uml_postsetup_start = .;
+	*(.uml.postsetup.init)
+	__uml_postsetup_end = .;
+  }
+	
+  .init.setup : {
+	INIT_SETUP(0)
+  }
+
+  PERCPU_SECTION(32)
+	
+  .initcall.init : {
+	INIT_CALLS
+  }
+
+  .con_initcall.init : {
+	CON_INITCALL
+  }
+
+  .exitcall : {
+	__exitcall_begin = .;
+	*(.exitcall.exit)
+	__exitcall_end = .;
+  }
+
+  .uml.exitcall : {
+	__uml_exitcall_begin = .;
+	*(.uml.exitcall.exit)
+	__uml_exitcall_end = .;
+  }
+
+  . = ALIGN(4);
+  .altinstructions : {
+	__alt_instructions = .;
+	*(.altinstructions)
+	__alt_instructions_end = .;
+  }
+  .altinstr_replacement : { *(.altinstr_replacement) }
+  /* .exit.text is discard at runtime, not link time, to deal with references
+     from .altinstructions and .eh_frame */
+  .exit.text : { EXIT_TEXT }
+  .exit.data : { *(.exit.data) }
+
+  .preinit_array : {
+	__preinit_array_start = .;
+	*(.preinit_array)
+	__preinit_array_end = .;
+  }
+  .init_array : {
+	__init_array_start = .;
+	*(.kasan_init)
+	*(.init_array.*)
+	*(.init_array)
+	__init_array_end = .;
+  }
+  .fini_array : {
+	__fini_array_start = .;
+	*(.fini_array)
+	__fini_array_end = .;
+  }
+
+   . = ALIGN(4096);
+  .init.ramfs : {
+	INIT_RAM_FS
+  }
+
diff --git a/arch/um/include/asm/cpufeature.h b/arch/um/include/asm/cpufeature.h
new file mode 100644
index 000000000..f7770083c
--- /dev/null
+++ b/arch/um/include/asm/cpufeature.h
@@ -0,0 +1,133 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_UM_CPUFEATURE_H
+#define _ASM_UM_CPUFEATURE_H
+
+#include <asm/processor.h>
+
+#if defined(__KERNEL__) && !defined(__ASSEMBLER__)
+
+#include <asm/asm.h>
+#include <linux/bitops.h>
+
+extern const char * const x86_cap_flags[NCAPINTS*32];
+extern const char * const x86_power_flags[32];
+#define X86_CAP_FMT "%s"
+#define x86_cap_flag(flag) x86_cap_flags[flag]
+
+/*
+ * In order to save room, we index into this array by doing
+ * X86_BUG_<name> - NCAPINTS*32.
+ */
+extern const char * const x86_bug_flags[NBUGINTS*32];
+
+#define test_cpu_cap(c, bit)						\
+	 test_bit(bit, (unsigned long *)((c)->x86_capability))
+
+/*
+ * There are 32 bits/features in each mask word.  The high bits
+ * (selected with (bit>>5) give us the word number and the low 5
+ * bits give us the bit/feature number inside the word.
+ * (1UL<<((bit)&31) gives us a mask for the feature_bit so we can
+ * see if it is set in the mask word.
+ */
+#define CHECK_BIT_IN_MASK_WORD(maskname, word, bit)	\
+	(((bit)>>5)==(word) && (1UL<<((bit)&31) & maskname##word ))
+
+#define cpu_has(c, bit)							\
+	 test_cpu_cap(c, bit)
+
+#define this_cpu_has(bit)						\
+	(__builtin_constant_p(bit) && REQUIRED_MASK_BIT_SET(bit) ? 1 :	\
+	 x86_this_cpu_test_bit(bit, cpu_info.x86_capability))
+
+/*
+ * This macro is for detection of features which need kernel
+ * infrastructure to be used.  It may *not* directly test the CPU
+ * itself.  Use the cpu_has() family if you want true runtime
+ * testing of CPU features, like in hypervisor code where you are
+ * supporting a possible guest feature where host support for it
+ * is not relevant.
+ */
+#define cpu_feature_enabled(bit)	\
+	(__builtin_constant_p(bit) && DISABLED_MASK_BIT_SET(bit) ? 0 : _static_cpu_has(bit))
+
+#define boot_cpu_has(bit)	cpu_has(&boot_cpu_data, bit)
+
+#define set_cpu_cap(c, bit)	set_bit(bit, (unsigned long *)((c)->x86_capability))
+
+extern void setup_clear_cpu_cap(unsigned int bit);
+
+#define setup_force_cpu_cap(bit) do { \
+	set_cpu_cap(&boot_cpu_data, bit);	\
+	set_bit(bit, (unsigned long *)cpu_caps_set);	\
+} while (0)
+
+#define setup_force_cpu_bug(bit) setup_force_cpu_cap(bit)
+
+static __always_inline bool __static_cpu_has(u16 bit)
+{
+	asm goto("1: jmp 6f\n"
+		 "2:\n"
+		 ".skip -(((5f-4f) - (2b-1b)) > 0) * "
+			 "((5f-4f) - (2b-1b)),0x90\n"
+		 "3:\n"
+		 ".section .altinstructions,\"a\"\n"
+		 " .long 1b - .\n"		/* src offset */
+		 " .long 4f - .\n"		/* repl offset */
+		 " .word %P[always]\n"		/* always replace */
+		 " .byte 3b - 1b\n"		/* src len */
+		 " .byte 5f - 4f\n"		/* repl len */
+		 " .byte 3b - 2b\n"		/* pad len */
+		 ".previous\n"
+		 ".section .altinstr_replacement,\"ax\"\n"
+		 "4: jmp %l[t_no]\n"
+		 "5:\n"
+		 ".previous\n"
+		 ".section .altinstructions,\"a\"\n"
+		 " .long 1b - .\n"		/* src offset */
+		 " .long 0\n"			/* no replacement */
+		 " .word %P[feature]\n"		/* feature bit */
+		 " .byte 3b - 1b\n"		/* src len */
+		 " .byte 0\n"			/* repl len */
+		 " .byte 0\n"			/* pad len */
+		 ".previous\n"
+		 ".section .altinstr_aux,\"ax\"\n"
+		 "6:\n"
+		 " testb %[bitnum],%[cap_byte]\n"
+		 " jnz %l[t_yes]\n"
+		 " jmp %l[t_no]\n"
+		 ".previous\n"
+		 : : [feature]  "i" (bit),
+		     [always]   "i" (X86_FEATURE_ALWAYS),
+		     [bitnum]   "i" (1 << (bit & 7)),
+		     [cap_byte] "m" (((const char *)boot_cpu_data.x86_capability)[bit >> 3])
+		 : : t_yes, t_no);
+t_yes:
+	return true;
+t_no:
+	return false;
+}
+
+#define _static_cpu_has(bit)					\
+(								\
+	__builtin_constant_p(boot_cpu_has(bit)) ?		\
+		boot_cpu_has(bit) :				\
+		_static_cpu_has(bit)				\
+)
+
+#define cpu_has_bug(c, bit)		cpu_has(c, (bit))
+#define set_cpu_bug(c, bit)		set_cpu_cap(c, (bit))
+
+#define static_cpu_has_bug(bit)		_static_cpu_has((bit))
+#define boot_cpu_has_bug(bit)		cpu_has_bug(&boot_cpu_data, (bit))
+#define boot_cpu_set_bug(bit)		set_cpu_cap(&boot_cpu_data, (bit))
+
+#define MAX_CPU_FEATURES		(NCAPINTS * 32)
+#define cpu_have_feature		boot_cpu_has
+
+#define CPU_FEATURE_TYPEFMT		"x86,ven%04Xfam%04Xmod%04X"
+#define CPU_FEATURE_TYPEVAL		boot_cpu_data.x86_vendor, boot_cpu_data.x86, \
+					boot_cpu_data.x86_model
+
+#endif /* defined(__KERNEL__) && !defined(__ASSEMBLER__) */
+#endif /* _ASM_UM_CPUFEATURE_H */
diff --git a/arch/um/include/asm/current.h b/arch/um/include/asm/current.h
new file mode 100644
index 000000000..159a29b3d
--- /dev/null
+++ b/arch/um/include/asm/current.h
@@ -0,0 +1,24 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __ASM_CURRENT_H
+#define __ASM_CURRENT_H
+
+#include <linux/compiler.h>
+#include <linux/threads.h>
+
+#ifndef __ASSEMBLER__
+
+#include <shared/smp.h>
+
+struct task_struct;
+extern struct task_struct *cpu_tasks[NR_CPUS];
+
+static __always_inline struct task_struct *get_current(void)
+{
+	return cpu_tasks[uml_curr_cpu()];
+}
+
+#define current get_current()
+
+#endif /* __ASSEMBLER__ */
+
+#endif /* __ASM_CURRENT_H */
diff --git a/arch/um/include/asm/delay.h b/arch/um/include/asm/delay.h
new file mode 100644
index 000000000..e79b2ab6f
--- /dev/null
+++ b/arch/um/include/asm/delay.h
@@ -0,0 +1,30 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __UM_DELAY_H
+#define __UM_DELAY_H
+#include <asm-generic/delay.h>
+#include <linux/time-internal.h>
+
+static inline void um_ndelay(unsigned long nsecs)
+{
+	if (time_travel_mode == TT_MODE_INFCPU ||
+	    time_travel_mode == TT_MODE_EXTERNAL) {
+		time_travel_ndelay(nsecs);
+		return;
+	}
+	ndelay(nsecs);
+}
+#undef ndelay
+#define ndelay(n) um_ndelay(n)
+
+static inline void um_udelay(unsigned long usecs)
+{
+	if (time_travel_mode == TT_MODE_INFCPU ||
+	    time_travel_mode == TT_MODE_EXTERNAL) {
+		time_travel_ndelay(1000 * usecs);
+		return;
+	}
+	udelay(usecs);
+}
+#undef udelay
+#define udelay(n) um_udelay(n)
+#endif /* __UM_DELAY_H */
diff --git a/arch/um/include/asm/dma.h b/arch/um/include/asm/dma.h
new file mode 100644
index 000000000..fdc53642c
--- /dev/null
+++ b/arch/um/include/asm/dma.h
@@ -0,0 +1,11 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __UM_DMA_H
+#define __UM_DMA_H
+
+#include <asm/io.h>
+
+extern unsigned long uml_physmem;
+
+#define MAX_DMA_ADDRESS (uml_physmem)
+
+#endif
diff --git a/arch/um/include/asm/fpu/api.h b/arch/um/include/asm/fpu/api.h
new file mode 100644
index 000000000..3abf67c83
--- /dev/null
+++ b/arch/um/include/asm/fpu/api.h
@@ -0,0 +1,22 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+#ifndef _ASM_UM_FPU_API_H
+#define _ASM_UM_FPU_API_H
+
+#include <linux/types.h>
+
+/* Copyright (c) 2020 Cambridge Greys Ltd
+ * Copyright (c) 2020 Red Hat Inc.
+ * A set of "dummy" defines to allow the direct inclusion
+ * of x86 optimized copy, xor, etc routines into the
+ * UML code tree. */
+
+#define kernel_fpu_begin() (void)0
+#define kernel_fpu_end() (void)0
+
+static inline bool irq_fpu_usable(void)
+{
+	return true;
+}
+
+
+#endif
diff --git a/arch/um/include/asm/futex.h b/arch/um/include/asm/futex.h
new file mode 100644
index 000000000..780aa6bfc
--- /dev/null
+++ b/arch/um/include/asm/futex.h
@@ -0,0 +1,14 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_UM_FUTEX_H
+#define _ASM_UM_FUTEX_H
+
+#include <linux/futex.h>
+#include <linux/uaccess.h>
+#include <asm/errno.h>
+
+
+int arch_futex_atomic_op_inuser(int op, u32 oparg, int *oval, u32 __user *uaddr);
+int futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
+			      u32 oldval, u32 newval);
+
+#endif
diff --git a/arch/um/include/asm/hardirq.h b/arch/um/include/asm/hardirq.h
new file mode 100644
index 000000000..8de71752a
--- /dev/null
+++ b/arch/um/include/asm/hardirq.h
@@ -0,0 +1,31 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __ASM_UM_HARDIRQ_H
+#define __ASM_UM_HARDIRQ_H
+
+#include <linux/cache.h>
+#include <linux/threads.h>
+
+#define __ARCH_IRQ_EXIT_IRQS_DISABLED 1
+
+typedef struct {
+	unsigned int __softirq_pending;
+#if IS_ENABLED(CONFIG_SMP)
+	unsigned int irq_resched_count;
+	unsigned int irq_call_count;
+#endif
+} ____cacheline_aligned irq_cpustat_t;
+
+DECLARE_PER_CPU_SHARED_ALIGNED(irq_cpustat_t, irq_stat);
+
+#define __ARCH_IRQ_STAT
+
+#define inc_irq_stat(member)	this_cpu_inc(irq_stat.member)
+
+#include <linux/irq.h>
+
+static inline void ack_bad_irq(unsigned int irq)
+{
+	pr_crit("unexpected IRQ trap at vector %02x\n", irq);
+}
+
+#endif /* __ASM_UM_HARDIRQ_H */
diff --git a/arch/um/include/asm/io.h b/arch/um/include/asm/io.h
new file mode 100644
index 000000000..9ea42cc74
--- /dev/null
+++ b/arch/um/include/asm/io.h
@@ -0,0 +1,26 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_UM_IO_H
+#define _ASM_UM_IO_H
+#include <linux/types.h>
+
+/* get emulated iomem (if desired) */
+#include <asm-generic/logic_io.h>
+
+#ifndef ioremap
+#define ioremap ioremap
+static inline void __iomem *ioremap(phys_addr_t offset, size_t size)
+{
+	return NULL;
+}
+#endif /* ioremap */
+
+#ifndef iounmap
+#define iounmap iounmap
+static inline void iounmap(void __iomem *addr)
+{
+}
+#endif /* iounmap */
+
+#include <asm-generic/io.h>
+
+#endif
diff --git a/arch/um/include/asm/irq.h b/arch/um/include/asm/irq.h
new file mode 100644
index 000000000..36dbedd1a
--- /dev/null
+++ b/arch/um/include/asm/irq.h
@@ -0,0 +1,40 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __UM_IRQ_H
+#define __UM_IRQ_H
+
+#define TIMER_IRQ		0
+#define UMN_IRQ			1
+#define UBD_IRQ			2
+#define UM_ETH_IRQ		3
+#define ACCEPT_IRQ		4
+#define MCONSOLE_IRQ		5
+#define WINCH_IRQ		6
+#define SIGIO_WRITE_IRQ 	7
+#define TELNETD_IRQ 		8
+#define XTERM_IRQ 		9
+#define RANDOM_IRQ 		10
+#define SIGCHLD_IRQ		11
+
+#ifdef CONFIG_UML_NET_VECTOR
+
+#define VECTOR_BASE_IRQ		(SIGCHLD_IRQ + 1)
+#define VECTOR_IRQ_SPACE	8
+
+#define UM_FIRST_DYN_IRQ (VECTOR_IRQ_SPACE + VECTOR_BASE_IRQ)
+
+#else
+
+#define UM_FIRST_DYN_IRQ (SIGCHLD_IRQ + 1)
+
+#endif
+
+#define UM_LAST_SIGNAL_IRQ	64
+/* If we have (simulated) PCI MSI, allow 64 more interrupt numbers for it */
+#ifdef CONFIG_PCI_MSI
+#define NR_IRQS			(UM_LAST_SIGNAL_IRQ + 64)
+#else
+#define NR_IRQS			UM_LAST_SIGNAL_IRQ
+#endif /* CONFIG_PCI_MSI */
+
+#include <asm-generic/irq.h>
+#endif
diff --git a/arch/um/include/asm/irqflags.h b/arch/um/include/asm/irqflags.h
new file mode 100644
index 000000000..31e49e089
--- /dev/null
+++ b/arch/um/include/asm/irqflags.h
@@ -0,0 +1,38 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __UM_IRQFLAGS_H
+#define __UM_IRQFLAGS_H
+
+int um_get_signals(void);
+int um_set_signals(int enable);
+void block_signals(void);
+void unblock_signals(void);
+
+#define arch_local_save_flags arch_local_save_flags
+static inline unsigned long arch_local_save_flags(void)
+{
+	return um_get_signals();
+}
+
+#define arch_local_irq_restore arch_local_irq_restore
+static inline void arch_local_irq_restore(unsigned long flags)
+{
+	um_set_signals(flags);
+}
+
+#define arch_local_irq_enable arch_local_irq_enable
+static inline void arch_local_irq_enable(void)
+{
+	unblock_signals();
+}
+
+#define arch_local_irq_disable arch_local_irq_disable
+static inline void arch_local_irq_disable(void)
+{
+	block_signals();
+}
+
+#define ARCH_IRQ_DISABLED	0
+
+#include <asm-generic/irqflags.h>
+
+#endif
diff --git a/arch/um/include/asm/kasan.h b/arch/um/include/asm/kasan.h
new file mode 100644
index 000000000..81bcdc0f9
--- /dev/null
+++ b/arch/um/include/asm/kasan.h
@@ -0,0 +1,31 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __ASM_UM_KASAN_H
+#define __ASM_UM_KASAN_H
+
+#include <linux/init.h>
+#include <linux/const.h>
+
+#define KASAN_SHADOW_OFFSET _AC(CONFIG_KASAN_SHADOW_OFFSET, UL)
+
+/* used in kasan_mem_to_shadow to divide by 8 */
+#define KASAN_SHADOW_SCALE_SHIFT 3
+
+#ifdef CONFIG_X86_64
+#define KASAN_HOST_USER_SPACE_END_ADDR 0x00007fffffffffffUL
+/* KASAN_SHADOW_SIZE is the size of total address space divided by 8 */
+#define KASAN_SHADOW_SIZE ((KASAN_HOST_USER_SPACE_END_ADDR + 1) >> \
+			KASAN_SHADOW_SCALE_SHIFT)
+#else
+#error "KASAN_SHADOW_SIZE is not defined for this sub-architecture"
+#endif /* CONFIG_X86_64 */
+
+#define KASAN_SHADOW_START (KASAN_SHADOW_OFFSET)
+#define KASAN_SHADOW_END (KASAN_SHADOW_START + KASAN_SHADOW_SIZE)
+
+#ifdef CONFIG_KASAN
+void kasan_init(void);
+#else
+static inline void kasan_init(void) { }
+#endif /* CONFIG_KASAN */
+
+#endif /* __ASM_UM_KASAN_H */
diff --git a/arch/um/include/asm/kvm_para.h b/arch/um/include/asm/kvm_para.h
new file mode 100644
index 000000000..14fab8f0b
--- /dev/null
+++ b/arch/um/include/asm/kvm_para.h
@@ -0,0 +1 @@
+#include <asm-generic/kvm_para.h>
diff --git a/arch/um/include/asm/mmu.h b/arch/um/include/asm/mmu.h
new file mode 100644
index 000000000..07d48738b
--- /dev/null
+++ b/arch/um/include/asm/mmu.h
@@ -0,0 +1,32 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* 
+ * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+ */
+
+#ifndef __ARCH_UM_MMU_H
+#define __ARCH_UM_MMU_H
+
+#include "linux/types.h"
+#include <linux/mutex.h>
+#include <linux/spinlock.h>
+#include <mm_id.h>
+
+typedef struct mm_context {
+	struct mm_id id;
+	struct mutex turnstile;
+
+	struct list_head list;
+
+	/* Address range in need of a TLB sync */
+	spinlock_t sync_tlb_lock;
+	unsigned long sync_tlb_range_from;
+	unsigned long sync_tlb_range_to;
+} mm_context_t;
+
+#define INIT_MM_CONTEXT(mm)						\
+	.context = {							\
+		.turnstile = __MUTEX_INITIALIZER(mm.context.turnstile),	\
+		.sync_tlb_lock = __SPIN_LOCK_INITIALIZER(mm.context.sync_tlb_lock), \
+	}
+
+#endif
diff --git a/arch/um/include/asm/mmu_context.h b/arch/um/include/asm/mmu_context.h
new file mode 100644
index 000000000..c727e56ba
--- /dev/null
+++ b/arch/um/include/asm/mmu_context.h
@@ -0,0 +1,29 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* 
+ * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+ */
+
+#ifndef __UM_MMU_CONTEXT_H
+#define __UM_MMU_CONTEXT_H
+
+#include <linux/sched.h>
+#include <linux/mm_types.h>
+#include <linux/mmap_lock.h>
+
+#include <asm/mm_hooks.h>
+#include <asm/mmu.h>
+
+static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next, 
+			     struct task_struct *tsk)
+{
+}
+
+#define init_new_context init_new_context
+extern int init_new_context(struct task_struct *task, struct mm_struct *mm);
+
+#define destroy_context destroy_context
+extern void destroy_context(struct mm_struct *mm);
+
+#include <asm-generic/mmu_context.h>
+
+#endif
diff --git a/arch/um/include/asm/msi.h b/arch/um/include/asm/msi.h
new file mode 100644
index 000000000..c8c6c381f
--- /dev/null
+++ b/arch/um/include/asm/msi.h
@@ -0,0 +1 @@
+#include <asm-generic/msi.h>
diff --git a/arch/um/include/asm/page.h b/arch/um/include/asm/page.h
new file mode 100644
index 000000000..e348ff489
--- /dev/null
+++ b/arch/um/include/asm/page.h
@@ -0,0 +1,98 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2000 - 2003 Jeff Dike (jdike@addtoit.com)
+ * Copyright 2003 PathScale, Inc.
+ */
+
+#ifndef __UM_PAGE_H
+#define __UM_PAGE_H
+
+#include <linux/const.h>
+
+#include <vdso/page.h>
+
+#ifndef __ASSEMBLER__
+
+struct page;
+
+#include <linux/pfn.h>
+#include <linux/types.h>
+#include <asm/vm-flags.h>
+
+/*
+ * These are used to make use of C type-checking..
+ */
+
+#define clear_page(page)	memset((void *)(page), 0, PAGE_SIZE)
+#define copy_page(to,from)	memcpy((void *)(to), (void *)(from), PAGE_SIZE)
+
+#define copy_user_page(to, from, vaddr, pg)	copy_page(to, from)
+
+typedef struct { unsigned long pte; } pte_t;
+typedef struct { unsigned long pgd; } pgd_t;
+
+#if CONFIG_PGTABLE_LEVELS > 2
+
+typedef struct { unsigned long pmd; } pmd_t;
+#define pmd_val(x)	((x).pmd)
+#define __pmd(x) ((pmd_t) { (x) } )
+
+#if CONFIG_PGTABLE_LEVELS > 3
+
+typedef struct { unsigned long pud; } pud_t;
+#define pud_val(x)	((x).pud)
+#define __pud(x) ((pud_t) { (x) } )
+
+#endif /* CONFIG_PGTABLE_LEVELS > 3 */
+#endif /* CONFIG_PGTABLE_LEVELS > 2 */
+
+#define pte_val(x)	((x).pte)
+
+#define pte_get_bits(p, bits) ((p).pte & (bits))
+#define pte_set_bits(p, bits) ((p).pte |= (bits))
+#define pte_clear_bits(p, bits) ((p).pte &= ~(bits))
+#define pte_copy(to, from) ((to).pte = (from).pte)
+#define pte_is_zero(p) (!((p).pte & ~_PAGE_NEEDSYNC))
+#define pte_set_val(p, phys, prot) (p).pte = (phys | pgprot_val(prot))
+
+typedef unsigned long phys_t;
+
+typedef struct { unsigned long pgprot; } pgprot_t;
+
+typedef struct page *pgtable_t;
+
+#define pgd_val(x)	((x).pgd)
+#define pgprot_val(x)	((x).pgprot)
+
+#define __pte(x) ((pte_t) { (x) } )
+#define __pgd(x) ((pgd_t) { (x) } )
+#define __pgprot(x)	((pgprot_t) { (x) } )
+
+extern unsigned long uml_physmem;
+
+#define PAGE_OFFSET (uml_physmem)
+#define KERNELBASE PAGE_OFFSET
+
+#define __va_space (8*1024*1024)
+
+#include <mem.h>
+
+/* Cast to unsigned long before casting to void * to avoid a warning from
+ * mmap_kmem about cutting a long long down to a void *.  Not sure that
+ * casting is the right thing, but 32-bit UML can't have 64-bit virtual
+ * addresses
+ */
+#define __pa(virt) uml_to_phys((void *) (unsigned long) (virt))
+#define __va(phys) uml_to_virt((unsigned long) (phys))
+
+#define phys_to_pfn(p) ((p) >> PAGE_SHIFT)
+#define pfn_to_phys(pfn) PFN_PHYS(pfn)
+
+#define virt_addr_valid(v) pfn_valid(phys_to_pfn(__pa(v)))
+
+#include <asm-generic/memory_model.h>
+#include <asm-generic/getorder.h>
+
+#endif	/* __ASSEMBLER__ */
+
+#endif	/* __UM_PAGE_H */
diff --git a/arch/um/include/asm/pci.h b/arch/um/include/asm/pci.h
new file mode 100644
index 000000000..238d2e7fa
--- /dev/null
+++ b/arch/um/include/asm/pci.h
@@ -0,0 +1,19 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef __ASM_UM_PCI_H
+#define __ASM_UM_PCI_H
+#include <linux/types.h>
+#include <asm/io.h>
+
+/* Generic PCI */
+#include <asm-generic/pci.h>
+
+#ifdef CONFIG_PCI_MSI
+/*
+ * This is a bit of an annoying hack, and it assumes we only have
+ * the virt-pci (if anything). Which is true, but still.
+ */
+void *pci_root_bus_fwnode(struct pci_bus *bus);
+#define pci_root_bus_fwnode	pci_root_bus_fwnode
+#endif
+
+#endif  /* __ASM_UM_PCI_H */
diff --git a/arch/um/include/asm/pgalloc.h b/arch/um/include/asm/pgalloc.h
new file mode 100644
index 000000000..826ec44b5
--- /dev/null
+++ b/arch/um/include/asm/pgalloc.h
@@ -0,0 +1,45 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* 
+ * Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com)
+ * Copyright 2003 PathScale, Inc.
+ * Derived from include/asm-i386/pgalloc.h and include/asm-i386/pgtable.h
+ */
+
+#ifndef __UM_PGALLOC_H
+#define __UM_PGALLOC_H
+
+#include <linux/mm.h>
+
+#include <asm-generic/pgalloc.h>
+
+#define pmd_populate_kernel(mm, pmd, pte) \
+	set_pmd(pmd, __pmd(_PAGE_TABLE + (unsigned long) __pa(pte)))
+
+#define pmd_populate(mm, pmd, pte) 				\
+	set_pmd(pmd, __pmd(_PAGE_TABLE +			\
+		((unsigned long long)page_to_pfn(pte) <<	\
+			(unsigned long long) PAGE_SHIFT)))
+
+/*
+ * Allocate and free page tables.
+ */
+extern pgd_t *pgd_alloc(struct mm_struct *);
+
+#define __pte_free_tlb(tlb, pte, address)	\
+	tlb_remove_ptdesc((tlb), page_ptdesc(pte))
+
+#if CONFIG_PGTABLE_LEVELS > 2
+
+#define __pmd_free_tlb(tlb, pmd, address)	\
+	tlb_remove_ptdesc((tlb), virt_to_ptdesc(pmd))
+
+#if CONFIG_PGTABLE_LEVELS > 3
+
+#define __pud_free_tlb(tlb, pud, address)	\
+	tlb_remove_ptdesc((tlb), virt_to_ptdesc(pud))
+
+#endif
+#endif
+
+#endif
+
diff --git a/arch/um/include/asm/pgtable-2level.h b/arch/um/include/asm/pgtable-2level.h
new file mode 100644
index 000000000..14ec16f92
--- /dev/null
+++ b/arch/um/include/asm/pgtable-2level.h
@@ -0,0 +1,42 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com)
+ * Copyright 2003 PathScale, Inc.
+ * Derived from include/asm-i386/pgtable.h
+ */
+
+#ifndef __UM_PGTABLE_2LEVEL_H
+#define __UM_PGTABLE_2LEVEL_H
+
+#include <asm-generic/pgtable-nopmd.h>
+
+/* PGDIR_SHIFT determines what a third-level page table entry can map */
+
+#define PGDIR_SHIFT	22
+#define PGDIR_SIZE	(1UL << PGDIR_SHIFT)
+#define PGDIR_MASK	(~(PGDIR_SIZE-1))
+
+/*
+ * entries per page directory level: the i386 is two-level, so
+ * we don't really have any PMD directory physically.
+ */
+#define PTRS_PER_PTE	1024
+#define USER_PTRS_PER_PGD ((TASK_SIZE + (PGDIR_SIZE - 1)) / PGDIR_SIZE)
+#define PTRS_PER_PGD	1024
+
+#define pte_ERROR(e) \
+        printk("%s:%d: bad pte %p(%08lx).\n", __FILE__, __LINE__, &(e), \
+	       pte_val(e))
+#define pgd_ERROR(e) \
+        printk("%s:%d: bad pgd %p(%08lx).\n", __FILE__, __LINE__, &(e), \
+	       pgd_val(e))
+
+static inline int pgd_needsync(pgd_t pgd)	{ return 0; }
+static inline void pgd_mkuptodate(pgd_t pgd)	{ }
+
+#define set_pmd(pmdptr, pmdval) (*(pmdptr) = (pmdval))
+
+#define pte_pfn(x) phys_to_pfn(pte_val(x))
+#define pfn_pmd(pfn, prot) __pmd(pfn_to_phys(pfn) | pgprot_val(prot))
+
+#endif
diff --git a/arch/um/include/asm/pgtable-4level.h b/arch/um/include/asm/pgtable-4level.h
new file mode 100644
index 000000000..7a271b7b8
--- /dev/null
+++ b/arch/um/include/asm/pgtable-4level.h
@@ -0,0 +1,110 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright 2003 PathScale Inc
+ * Derived from include/asm-i386/pgtable.h
+ */
+
+#ifndef __UM_PGTABLE_4LEVEL_H
+#define __UM_PGTABLE_4LEVEL_H
+
+#include <asm-generic/pgtable-nop4d.h>
+
+/* PGDIR_SHIFT determines what a fourth-level page table entry can map */
+
+#define PGDIR_SHIFT	39
+#define PGDIR_SIZE	(1UL << PGDIR_SHIFT)
+#define PGDIR_MASK	(~(PGDIR_SIZE-1))
+
+/* PUD_SHIFT determines the size of the area a third-level page table can
+ * map
+ */
+
+#define PUD_SHIFT	30
+#define PUD_SIZE	(1UL << PUD_SHIFT)
+#define PUD_MASK	(~(PUD_SIZE-1))
+
+/* PMD_SHIFT determines the size of the area a second-level page table can
+ * map
+ */
+
+#define PMD_SHIFT	21
+#define PMD_SIZE	(1UL << PMD_SHIFT)
+#define PMD_MASK	(~(PMD_SIZE-1))
+
+/*
+ * entries per page directory level
+ */
+
+#define PTRS_PER_PTE 512
+#define PTRS_PER_PMD 512
+#define PTRS_PER_PUD 512
+#define PTRS_PER_PGD 512
+
+#define USER_PTRS_PER_PGD ((TASK_SIZE + (PGDIR_SIZE - 1)) / PGDIR_SIZE)
+
+#define pte_ERROR(e) \
+        printk("%s:%d: bad pte %p(%016lx).\n", __FILE__, __LINE__, &(e), \
+	       pte_val(e))
+#define pmd_ERROR(e) \
+        printk("%s:%d: bad pmd %p(%016lx).\n", __FILE__, __LINE__, &(e), \
+	       pmd_val(e))
+#define pud_ERROR(e) \
+        printk("%s:%d: bad pud %p(%016lx).\n", __FILE__, __LINE__, &(e), \
+	       pud_val(e))
+#define pgd_ERROR(e) \
+        printk("%s:%d: bad pgd %p(%016lx).\n", __FILE__, __LINE__, &(e), \
+	       pgd_val(e))
+
+#define pud_none(x)	(!(pud_val(x) & ~_PAGE_NEEDSYNC))
+#define	pud_bad(x)	((pud_val(x) & (~PAGE_MASK & ~_PAGE_USER)) != _KERNPG_TABLE)
+#define pud_present(x)	(pud_val(x) & _PAGE_PRESENT)
+#define pud_populate(mm, pud, pmd) \
+	set_pud(pud, __pud(_PAGE_TABLE + __pa(pmd)))
+
+#define set_pud(pudptr, pudval) (*(pudptr) = (pudval))
+
+#define p4d_none(x)	(!(p4d_val(x) & ~_PAGE_NEEDSYNC))
+#define	p4d_bad(x)	((p4d_val(x) & (~PAGE_MASK & ~_PAGE_USER)) != _KERNPG_TABLE)
+#define p4d_present(x)	(p4d_val(x) & _PAGE_PRESENT)
+#define p4d_populate(mm, p4d, pud) \
+	set_p4d(p4d, __p4d(_PAGE_TABLE + __pa(pud)))
+
+#define set_p4d(p4dptr, p4dval) (*(p4dptr) = (p4dval))
+
+
+static inline int pgd_needsync(pgd_t pgd)
+{
+	return pgd_val(pgd) & _PAGE_NEEDSYNC;
+}
+
+static inline void pgd_mkuptodate(pgd_t pgd) { pgd_val(pgd) &= ~_PAGE_NEEDSYNC; }
+
+#define set_pmd(pmdptr, pmdval) (*(pmdptr) = (pmdval))
+
+static inline void pud_clear (pud_t *pud)
+{
+	set_pud(pud, __pud(_PAGE_NEEDSYNC));
+}
+
+static inline void p4d_clear (p4d_t *p4d)
+{
+	set_p4d(p4d, __p4d(_PAGE_NEEDSYNC));
+}
+
+#define pud_page(pud) phys_to_page(pud_val(pud) & PAGE_MASK)
+#define pud_pgtable(pud) ((pmd_t *) __va(pud_val(pud) & PAGE_MASK))
+
+#define p4d_page(p4d) phys_to_page(p4d_val(p4d) & PAGE_MASK)
+#define p4d_pgtable(p4d) ((pud_t *) __va(p4d_val(p4d) & PAGE_MASK))
+
+static inline unsigned long pte_pfn(pte_t pte)
+{
+	return phys_to_pfn(pte_val(pte));
+}
+
+static inline pmd_t pfn_pmd(unsigned long page_nr, pgprot_t pgprot)
+{
+	return __pmd((page_nr << PAGE_SHIFT) | pgprot_val(pgprot));
+}
+
+#endif
diff --git a/arch/um/include/asm/pgtable.h b/arch/um/include/asm/pgtable.h
new file mode 100644
index 000000000..88ea84343
--- /dev/null
+++ b/arch/um/include/asm/pgtable.h
@@ -0,0 +1,328 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+ * Copyright 2003 PathScale, Inc.
+ * Derived from include/asm-i386/pgtable.h
+ */
+
+#ifndef __UM_PGTABLE_H
+#define __UM_PGTABLE_H
+
+#include <asm/page.h>
+#include <linux/mm_types.h>
+
+#define _PAGE_PRESENT	0x001
+#define _PAGE_NEEDSYNC	0x002
+#define _PAGE_RW	0x020
+#define _PAGE_USER	0x040
+#define _PAGE_ACCESSED	0x080
+#define _PAGE_DIRTY	0x100
+/* If _PAGE_PRESENT is clear, we use these: */
+#define _PAGE_PROTNONE	0x010	/* if the user mapped it with PROT_NONE;
+				   pte_present gives true */
+
+/* We borrow bit 10 to store the exclusive marker in swap PTEs. */
+#define _PAGE_SWP_EXCLUSIVE	0x400
+
+#if CONFIG_PGTABLE_LEVELS == 4
+#include <asm/pgtable-4level.h>
+#elif CONFIG_PGTABLE_LEVELS == 2
+#include <asm/pgtable-2level.h>
+#else
+#error "Unsupported number of page table levels"
+#endif
+
+extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
+
+/* Just any arbitrary offset to the start of the vmalloc VM area: the
+ * current 8MB value just means that there will be a 8MB "hole" after the
+ * physical memory until the kernel virtual memory starts.  That means that
+ * any out-of-bounds memory accesses will hopefully be caught.
+ * The vmalloc() routines leaves a hole of 4kB between each vmalloced
+ * area for the same reason. ;)
+ */
+
+#ifndef COMPILE_OFFSETS
+#include <as-layout.h> /* for high_physmem */
+#endif
+
+#define VMALLOC_OFFSET	(__va_space)
+#define VMALLOC_START	((high_physmem + VMALLOC_OFFSET) & ~(VMALLOC_OFFSET-1))
+#define VMALLOC_END	(TASK_SIZE-2*PAGE_SIZE)
+#define MODULES_VADDR	VMALLOC_START
+#define MODULES_END	VMALLOC_END
+
+#define _PAGE_TABLE	(_PAGE_PRESENT | _PAGE_RW | _PAGE_USER | _PAGE_ACCESSED | _PAGE_DIRTY)
+#define _KERNPG_TABLE	(_PAGE_PRESENT | _PAGE_RW | _PAGE_ACCESSED | _PAGE_DIRTY)
+#define _PAGE_CHG_MASK	(PAGE_MASK | _PAGE_ACCESSED | _PAGE_DIRTY)
+#define __PAGE_KERNEL_EXEC                                              \
+	 (_PAGE_PRESENT | _PAGE_RW | _PAGE_DIRTY | _PAGE_ACCESSED)
+#define PAGE_NONE	__pgprot(_PAGE_PROTNONE | _PAGE_ACCESSED)
+#define PAGE_SHARED	__pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_USER | _PAGE_ACCESSED)
+#define PAGE_COPY	__pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_ACCESSED)
+#define PAGE_READONLY	__pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_ACCESSED)
+#define PAGE_KERNEL	__pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_DIRTY | _PAGE_ACCESSED)
+#define PAGE_KERNEL_EXEC	__pgprot(__PAGE_KERNEL_EXEC)
+
+/*
+ * The i386 can't do page protection for execute, and considers that the same
+ * are read.
+ * Also, write permissions imply read permissions. This is the closest we can
+ * get..
+ */
+
+#define pte_clear(mm, addr, xp) pte_set_val(*(xp), (phys_t) 0, __pgprot(_PAGE_NEEDSYNC))
+
+#define pmd_none(x)	(!((unsigned long)pmd_val(x) & ~_PAGE_NEEDSYNC))
+#define	pmd_bad(x)	((pmd_val(x) & (~PAGE_MASK & ~_PAGE_USER)) != _KERNPG_TABLE)
+
+#define pmd_present(x)	(pmd_val(x) & _PAGE_PRESENT)
+#define pmd_clear(xp)	do { pmd_val(*(xp)) = _PAGE_NEEDSYNC; } while (0)
+
+#define pmd_needsync(x)   (pmd_val(x) & _PAGE_NEEDSYNC)
+#define pmd_mkuptodate(x) (pmd_val(x) &= ~_PAGE_NEEDSYNC)
+
+#define pud_needsync(x)   (pud_val(x) & _PAGE_NEEDSYNC)
+#define pud_mkuptodate(x) (pud_val(x) &= ~_PAGE_NEEDSYNC)
+
+#define p4d_needsync(x)   (p4d_val(x) & _PAGE_NEEDSYNC)
+#define p4d_mkuptodate(x) (p4d_val(x) &= ~_PAGE_NEEDSYNC)
+
+#define pmd_pfn(pmd) (pmd_val(pmd) >> PAGE_SHIFT)
+#define pmd_page(pmd) phys_to_page(pmd_val(pmd) & PAGE_MASK)
+
+#define pte_page(x) pfn_to_page(pte_pfn(x))
+
+#define pte_present(x)	pte_get_bits(x, (_PAGE_PRESENT | _PAGE_PROTNONE))
+
+/*
+ * =================================
+ * Flags checking section.
+ * =================================
+ */
+
+static inline int pte_none(pte_t pte)
+{
+	return pte_is_zero(pte);
+}
+
+/*
+ * The following only work if pte_present() is true.
+ * Undefined behaviour if not..
+ */
+static inline int pte_read(pte_t pte)
+{
+	return !pte_get_bits(pte, _PAGE_PROTNONE);
+}
+
+static inline int pte_exec(pte_t pte)
+{
+	return !pte_get_bits(pte, _PAGE_PROTNONE);
+}
+
+static inline int pte_write(pte_t pte)
+{
+	return((pte_get_bits(pte, _PAGE_RW)) &&
+	       !(pte_get_bits(pte, _PAGE_PROTNONE)));
+}
+
+static inline int pte_dirty(pte_t pte)
+{
+	return pte_get_bits(pte, _PAGE_DIRTY);
+}
+
+static inline int pte_young(pte_t pte)
+{
+	return pte_get_bits(pte, _PAGE_ACCESSED);
+}
+
+static inline int pte_needsync(pte_t pte)
+{
+	return pte_get_bits(pte, _PAGE_NEEDSYNC);
+}
+
+/*
+ * =================================
+ * Flags setting section.
+ * =================================
+ */
+
+static inline pte_t pte_mkclean(pte_t pte)
+{
+	pte_clear_bits(pte, _PAGE_DIRTY);
+	return(pte);
+}
+
+static inline pte_t pte_mkold(pte_t pte)
+{
+	pte_clear_bits(pte, _PAGE_ACCESSED);
+	return(pte);
+}
+
+static inline pte_t pte_wrprotect(pte_t pte)
+{
+	pte_clear_bits(pte, _PAGE_RW);
+	return pte;
+}
+
+static inline pte_t pte_mkread(pte_t pte)
+{
+	pte_set_bits(pte, _PAGE_USER);
+	return pte;
+}
+
+static inline pte_t pte_mkdirty(pte_t pte)
+{
+	pte_set_bits(pte, _PAGE_DIRTY);
+	return(pte);
+}
+
+static inline pte_t pte_mkyoung(pte_t pte)
+{
+	pte_set_bits(pte, _PAGE_ACCESSED);
+	return(pte);
+}
+
+static inline pte_t pte_mkwrite_novma(pte_t pte)
+{
+	pte_set_bits(pte, _PAGE_RW);
+	return pte;
+}
+
+static inline pte_t pte_mkuptodate(pte_t pte)
+{
+	pte_clear_bits(pte, _PAGE_NEEDSYNC);
+	return pte;
+}
+
+static inline pte_t pte_mkneedsync(pte_t pte)
+{
+	pte_set_bits(pte, _PAGE_NEEDSYNC);
+	return(pte);
+}
+
+static inline void set_pte(pte_t *pteptr, pte_t pteval)
+{
+	pte_copy(*pteptr, pteval);
+
+	/* If it's a swap entry, it needs to be marked _PAGE_NEEDSYNC so
+	 * update_pte_range knows to unmap it.
+	 */
+
+	*pteptr = pte_mkneedsync(*pteptr);
+}
+
+#define PFN_PTE_SHIFT		PAGE_SHIFT
+
+static inline void um_tlb_mark_sync(struct mm_struct *mm, unsigned long start,
+				    unsigned long end)
+{
+	guard(spinlock_irqsave)(&mm->context.sync_tlb_lock);
+
+	if (!mm->context.sync_tlb_range_to) {
+		mm->context.sync_tlb_range_from = start;
+		mm->context.sync_tlb_range_to = end;
+	} else {
+		if (start < mm->context.sync_tlb_range_from)
+			mm->context.sync_tlb_range_from = start;
+		if (end > mm->context.sync_tlb_range_to)
+			mm->context.sync_tlb_range_to = end;
+	}
+}
+
+#define set_ptes set_ptes
+static inline void set_ptes(struct mm_struct *mm, unsigned long addr,
+			    pte_t *ptep, pte_t pte, int nr)
+{
+	/* Basically the default implementation */
+	size_t length = nr * PAGE_SIZE;
+
+	for (;;) {
+		set_pte(ptep, pte);
+		if (--nr == 0)
+			break;
+		ptep++;
+		pte = __pte(pte_val(pte) + (nr << PFN_PTE_SHIFT));
+	}
+
+	um_tlb_mark_sync(mm, addr, addr + length);
+}
+
+#define __HAVE_ARCH_PTE_SAME
+static inline int pte_same(pte_t pte_a, pte_t pte_b)
+{
+	return !((pte_val(pte_a) ^ pte_val(pte_b)) & ~_PAGE_NEEDSYNC);
+}
+
+#define __virt_to_page(virt) phys_to_page(__pa(virt))
+#define virt_to_page(addr) __virt_to_page((const unsigned long) addr)
+
+static inline pte_t pfn_pte(unsigned long pfn, pgprot_t pgprot)
+{
+	pte_t pte;
+
+	pte_set_val(pte, pfn_to_phys(pfn), pgprot);
+
+	return pte;
+}
+
+static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
+{
+	pte_set_val(pte, (pte_val(pte) & _PAGE_CHG_MASK), newprot);
+	return pte;
+}
+
+/*
+ * the pmd page can be thought of an array like this: pmd_t[PTRS_PER_PMD]
+ *
+ * this macro returns the index of the entry in the pmd page which would
+ * control the given virtual address
+ */
+#define pmd_page_vaddr(pmd) ((unsigned long) __va(pmd_val(pmd) & PAGE_MASK))
+
+struct mm_struct;
+extern pte_t *virt_to_pte(struct mm_struct *mm, unsigned long addr);
+
+#define update_mmu_cache(vma,address,ptep) do {} while (0)
+#define update_mmu_cache_range(vmf, vma, address, ptep, nr) do {} while (0)
+
+/*
+ * Encode/decode swap entries and swap PTEs. Swap PTEs are all PTEs that
+ * are !pte_none() && !pte_present().
+ *
+ * Format of swap PTEs:
+ *
+ *   3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1
+ *   1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0
+ *   <--------------- offset ----------------> E < type -> 0 0 0 1 0
+ *
+ *   E is the exclusive marker that is not stored in swap entries.
+ *   _PAGE_NEEDSYNC (bit 1) is always set to 1 in set_pte().
+ */
+#define __swp_type(x)			(((x).val >> 5) & 0x1f)
+#define __swp_offset(x)			((x).val >> 11)
+
+#define __swp_entry(type, offset) \
+	((swp_entry_t) { (((type) & 0x1f) << 5) | ((offset) << 11) })
+#define __pte_to_swp_entry(pte) \
+	((swp_entry_t) { pte_val(pte_mkuptodate(pte)) })
+#define __swp_entry_to_pte(x)		((pte_t) { (x).val })
+
+static inline bool pte_swp_exclusive(pte_t pte)
+{
+	return pte_get_bits(pte, _PAGE_SWP_EXCLUSIVE);
+}
+
+static inline pte_t pte_swp_mkexclusive(pte_t pte)
+{
+	pte_set_bits(pte, _PAGE_SWP_EXCLUSIVE);
+	return pte;
+}
+
+static inline pte_t pte_swp_clear_exclusive(pte_t pte)
+{
+	pte_clear_bits(pte, _PAGE_SWP_EXCLUSIVE);
+	return pte;
+}
+
+#endif
diff --git a/arch/um/include/asm/processor-generic.h b/arch/um/include/asm/processor-generic.h
new file mode 100644
index 000000000..7854d51b6
--- /dev/null
+++ b/arch/um/include/asm/processor-generic.h
@@ -0,0 +1,88 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* 
+ * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+ */
+
+#ifndef __UM_PROCESSOR_GENERIC_H
+#define __UM_PROCESSOR_GENERIC_H
+
+struct pt_regs;
+
+struct task_struct;
+
+#include <asm/ptrace.h>
+#include <sysdep/archsetjmp.h>
+
+#include <linux/prefetch.h>
+
+#include <asm/cpufeatures.h>
+
+struct mm_struct;
+
+struct thread_struct {
+	struct pt_regs *segv_regs;
+	struct task_struct *prev_sched;
+	struct arch_thread arch;
+	jmp_buf switch_buf;
+	struct {
+		struct {
+			int (*proc)(void *);
+			void *arg;
+		} thread;
+	} request;
+
+	void *segv_continue;
+
+	/* Contains variable sized FP registers */
+	struct pt_regs regs;
+};
+
+#define INIT_THREAD \
+{ \
+	.regs		   	= EMPTY_REGS,	\
+	.prev_sched		= NULL, \
+	.arch			= INIT_ARCH_THREAD, \
+	.request		= { } \
+}
+
+/*
+ * User space process size: 3GB (default).
+ */
+extern unsigned long task_size;
+
+#define TASK_SIZE (task_size)
+
+#undef STACK_TOP
+#undef STACK_TOP_MAX
+
+extern unsigned long stacksizelim;
+
+#define STACK_ROOM	(stacksizelim)
+#define STACK_TOP	(TASK_SIZE - 2 * PAGE_SIZE)
+#define STACK_TOP_MAX	STACK_TOP
+
+/* This decides where the kernel will search for a free chunk of vm
+ * space during mmap's.
+ */
+#define TASK_UNMAPPED_BASE	(0x40000000)
+
+extern void start_thread(struct pt_regs *regs, unsigned long entry, 
+			 unsigned long stack);
+
+struct cpuinfo_um {
+	unsigned long loops_per_jiffy;
+	int cache_alignment;
+	union {
+		__u32		x86_capability[NCAPINTS + NBUGINTS];
+		unsigned long	x86_capability_alignment;
+	};
+};
+
+extern struct cpuinfo_um boot_cpu_data;
+
+#define cache_line_size()	(boot_cpu_data.cache_alignment)
+
+#define KSTK_REG(tsk, reg) get_thread_reg(reg, &tsk->thread.switch_buf)
+extern unsigned long __get_wchan(struct task_struct *p);
+
+#endif
diff --git a/arch/um/include/asm/ptrace-generic.h b/arch/um/include/asm/ptrace-generic.h
new file mode 100644
index 000000000..86d74f9d3
--- /dev/null
+++ b/arch/um/include/asm/ptrace-generic.h
@@ -0,0 +1,49 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* 
+ * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+ */
+
+#ifndef __UM_PTRACE_GENERIC_H
+#define __UM_PTRACE_GENERIC_H
+
+#ifndef __ASSEMBLER__
+
+#include <sysdep/ptrace.h>
+
+struct pt_regs {
+	struct uml_pt_regs regs;
+};
+
+#define arch_has_single_step()	(1)
+
+#define EMPTY_REGS { .regs = EMPTY_UML_PT_REGS }
+
+#define PT_REGS_IP(r) UPT_IP(&(r)->regs)
+#define PT_REGS_SP(r) UPT_SP(&(r)->regs)
+
+#define PT_REGS_RESTART_SYSCALL(r) UPT_RESTART_SYSCALL(&(r)->regs)
+
+#define PT_REGS_SYSCALL_NR(r) UPT_SYSCALL_NR(&(r)->regs)
+
+#define instruction_pointer(regs) PT_REGS_IP(regs)
+
+#define PTRACE_OLDSETOPTIONS 21
+
+struct task_struct;
+
+extern long subarch_ptrace(struct task_struct *child, long request,
+	unsigned long addr, unsigned long data);
+extern unsigned long getreg(struct task_struct *child, int regno);
+extern int putreg(struct task_struct *child, int regno, unsigned long value);
+
+extern int poke_user(struct task_struct *child, long addr, long data);
+extern int peek_user(struct task_struct *child, long addr, long data);
+
+extern int arch_set_tls(struct task_struct *new, unsigned long tls);
+extern void clear_flushed_tls(struct task_struct *task);
+extern int syscall_trace_enter(struct pt_regs *regs);
+extern void syscall_trace_leave(struct pt_regs *regs);
+
+#endif
+
+#endif
diff --git a/arch/um/include/asm/sections.h b/arch/um/include/asm/sections.h
new file mode 100644
index 000000000..a3c1fb6ed
--- /dev/null
+++ b/arch/um/include/asm/sections.h
@@ -0,0 +1,10 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __UM_SECTIONS_H
+#define __UM_SECTIONS_H
+
+#include <asm-generic/sections.h>
+
+extern char __binary_start[];
+extern char __syscall_stub_start[], __syscall_stub_end[];
+
+#endif
diff --git a/arch/um/include/asm/setup.h b/arch/um/include/asm/setup.h
new file mode 100644
index 000000000..80ada899f
--- /dev/null
+++ b/arch/um/include/asm/setup.h
@@ -0,0 +1,11 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef SETUP_H_INCLUDED
+#define SETUP_H_INCLUDED
+
+/* POSIX mandated with _POSIX_ARG_MAX that we can rely on 4096 chars in the
+ * command line, so this choice is ok.
+ */
+
+#define COMMAND_LINE_SIZE 4096
+
+#endif		/* SETUP_H_INCLUDED */
diff --git a/arch/um/include/asm/smp.h b/arch/um/include/asm/smp.h
new file mode 100644
index 000000000..be1743a6f
--- /dev/null
+++ b/arch/um/include/asm/smp.h
@@ -0,0 +1,20 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __UM_SMP_H
+#define __UM_SMP_H
+
+#if IS_ENABLED(CONFIG_SMP)
+
+#include <linux/cpumask.h>
+#include <shared/smp.h>
+
+#define raw_smp_processor_id() uml_curr_cpu()
+
+void arch_smp_send_reschedule(int cpu);
+
+void arch_send_call_function_single_ipi(int cpu);
+
+void arch_send_call_function_ipi_mask(const struct cpumask *mask);
+
+#endif /* CONFIG_SMP */
+
+#endif
diff --git a/arch/um/include/asm/stacktrace.h b/arch/um/include/asm/stacktrace.h
new file mode 100644
index 000000000..436b55952
--- /dev/null
+++ b/arch/um/include/asm/stacktrace.h
@@ -0,0 +1,43 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_UML_STACKTRACE_H
+#define _ASM_UML_STACKTRACE_H
+
+#include <linux/uaccess.h>
+#include <linux/ptrace.h>
+
+struct stack_frame {
+	struct stack_frame *next_frame;
+	unsigned long return_address;
+};
+
+struct stacktrace_ops {
+	void (*address)(void *data, unsigned long address, int reliable);
+};
+
+#ifdef CONFIG_FRAME_POINTER
+static inline unsigned long
+get_frame_pointer(struct task_struct *task, struct pt_regs *segv_regs)
+{
+	if (!task || task == current)
+		return segv_regs ? PT_REGS_BP(segv_regs) : current_bp();
+	return KSTK_EBP(task);
+}
+#else
+static inline unsigned long
+get_frame_pointer(struct task_struct *task, struct pt_regs *segv_regs)
+{
+	return 0;
+}
+#endif
+
+static inline unsigned long
+*get_stack_pointer(struct task_struct *task, struct pt_regs *segv_regs)
+{
+	if (!task || task == current)
+		return segv_regs ? (unsigned long *)PT_REGS_SP(segv_regs) : current_sp();
+	return (unsigned long *)KSTK_ESP(task);
+}
+
+void dump_trace(struct task_struct *tsk, const struct stacktrace_ops *ops, void *data);
+
+#endif /* _ASM_UML_STACKTRACE_H */
diff --git a/arch/um/include/asm/syscall-generic.h b/arch/um/include/asm/syscall-generic.h
new file mode 100644
index 000000000..bcd73bcfe
--- /dev/null
+++ b/arch/um/include/asm/syscall-generic.h
@@ -0,0 +1,86 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Access to user system call parameters and results
+ *
+ * See asm-generic/syscall.h for function descriptions.
+ *
+ * Copyright (C) 2015 Mickaël Salaün <mic@digikod.net>
+ */
+
+#ifndef __UM_SYSCALL_GENERIC_H
+#define __UM_SYSCALL_GENERIC_H
+
+#include <asm/ptrace.h>
+#include <linux/err.h>
+#include <linux/sched.h>
+#include <sysdep/ptrace.h>
+
+static inline int syscall_get_nr(struct task_struct *task, struct pt_regs *regs)
+{
+
+	return PT_REGS_SYSCALL_NR(regs);
+}
+
+static inline void syscall_set_nr(struct task_struct *task, struct pt_regs *regs, int nr)
+{
+	PT_REGS_SYSCALL_NR(regs) = nr;
+}
+
+static inline void syscall_rollback(struct task_struct *task,
+				    struct pt_regs *regs)
+{
+	/* do nothing */
+}
+
+static inline long syscall_get_error(struct task_struct *task,
+				     struct pt_regs *regs)
+{
+	const long error = regs_return_value(regs);
+
+	return IS_ERR_VALUE(error) ? error : 0;
+}
+
+static inline long syscall_get_return_value(struct task_struct *task,
+					    struct pt_regs *regs)
+{
+	return regs_return_value(regs);
+}
+
+static inline void syscall_set_return_value(struct task_struct *task,
+					    struct pt_regs *regs,
+					    int error, long val)
+{
+	PT_REGS_SET_SYSCALL_RETURN(regs, (long) error ?: val);
+}
+
+static inline void syscall_get_arguments(struct task_struct *task,
+					 struct pt_regs *regs,
+					 unsigned long *args)
+{
+	const struct uml_pt_regs *r = &regs->regs;
+
+	*args++ = UPT_SYSCALL_ARG1(r);
+	*args++ = UPT_SYSCALL_ARG2(r);
+	*args++ = UPT_SYSCALL_ARG3(r);
+	*args++ = UPT_SYSCALL_ARG4(r);
+	*args++ = UPT_SYSCALL_ARG5(r);
+	*args   = UPT_SYSCALL_ARG6(r);
+}
+
+static inline void syscall_set_arguments(struct task_struct *task,
+					 struct pt_regs *regs,
+					 const unsigned long *args)
+{
+	struct uml_pt_regs *r = &regs->regs;
+
+	UPT_SYSCALL_ARG1(r) = *args++;
+	UPT_SYSCALL_ARG2(r) = *args++;
+	UPT_SYSCALL_ARG3(r) = *args++;
+	UPT_SYSCALL_ARG4(r) = *args++;
+	UPT_SYSCALL_ARG5(r) = *args++;
+	UPT_SYSCALL_ARG6(r) = *args;
+}
+
+/* See arch/x86/um/asm/syscall.h for syscall_get_arch() definition. */
+
+#endif	/* __UM_SYSCALL_GENERIC_H */
diff --git a/arch/um/include/asm/thread_info.h b/arch/um/include/asm/thread_info.h
new file mode 100644
index 000000000..7a6f4dc99
--- /dev/null
+++ b/arch/um/include/asm/thread_info.h
@@ -0,0 +1,62 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+ */
+
+#ifndef __UM_THREAD_INFO_H
+#define __UM_THREAD_INFO_H
+
+#define THREAD_SIZE_ORDER CONFIG_KERNEL_STACK_ORDER
+#define THREAD_SIZE ((1 << CONFIG_KERNEL_STACK_ORDER) * PAGE_SIZE)
+
+#ifndef __ASSEMBLER__
+
+#include <asm/types.h>
+#include <asm/page.h>
+#include <asm/segment.h>
+#include <sysdep/ptrace_user.h>
+
+struct thread_info {
+	unsigned long		flags;		/* low level flags */
+	__u32			cpu;		/* current CPU */
+	int			preempt_count;  /* 0 => preemptable,
+						   <0 => BUG */
+};
+
+#define INIT_THREAD_INFO(tsk)			\
+{						\
+	.flags =		0,		\
+	.cpu =		0,			\
+	.preempt_count = INIT_PREEMPT_COUNT,	\
+}
+
+#endif
+
+#define TIF_SYSCALL_TRACE	0	/* syscall trace active */
+#define TIF_SIGPENDING		1	/* signal pending */
+#define TIF_NEED_RESCHED	2	/* rescheduling necessary */
+#define TIF_NOTIFY_SIGNAL	3	/* signal notifications exist */
+#define TIF_RESTART_BLOCK	4
+#define TIF_MEMDIE		5	/* is terminating due to OOM killer */
+#define TIF_SYSCALL_AUDIT	6
+#define TIF_RESTORE_SIGMASK	7
+#define TIF_NOTIFY_RESUME	8
+#define TIF_SECCOMP		9	/* secure computing */
+#define TIF_SINGLESTEP		10	/* single stepping userspace */
+#define TIF_SYSCALL_TRACEPOINT	11	/* syscall tracepoint instrumentation */
+
+
+#define _TIF_SYSCALL_TRACE	(1 << TIF_SYSCALL_TRACE)
+#define _TIF_SIGPENDING		(1 << TIF_SIGPENDING)
+#define _TIF_NEED_RESCHED	(1 << TIF_NEED_RESCHED)
+#define _TIF_NOTIFY_SIGNAL	(1 << TIF_NOTIFY_SIGNAL)
+#define _TIF_MEMDIE		(1 << TIF_MEMDIE)
+#define _TIF_SYSCALL_AUDIT	(1 << TIF_SYSCALL_AUDIT)
+#define _TIF_NOTIFY_RESUME	(1 << TIF_NOTIFY_RESUME)
+#define _TIF_SECCOMP		(1 << TIF_SECCOMP)
+#define _TIF_SINGLESTEP		(1 << TIF_SINGLESTEP)
+
+#define _TIF_WORK_MASK		(_TIF_NEED_RESCHED | _TIF_SIGPENDING | _TIF_NOTIFY_SIGNAL | \
+				 _TIF_NOTIFY_RESUME)
+
+#endif
diff --git a/arch/um/include/asm/timex.h b/arch/um/include/asm/timex.h
new file mode 100644
index 000000000..39e392ebc
--- /dev/null
+++ b/arch/um/include/asm/timex.h
@@ -0,0 +1,13 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __UM_TIMEX_H
+#define __UM_TIMEX_H
+
+/*
+ * Do not fall back to the host architecture header because latter likely
+ * includes facilities like cpu_feature_enabled() which are present only
+ * there. That would result in build breakages and/or efforts to "emulate"
+ * those facilities in UML.
+ */
+#include <asm-generic/timex.h>
+
+#endif
diff --git a/arch/um/include/asm/tlb.h b/arch/um/include/asm/tlb.h
new file mode 100644
index 000000000..0422467bd
--- /dev/null
+++ b/arch/um/include/asm/tlb.h
@@ -0,0 +1,11 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __UM_TLB_H
+#define __UM_TLB_H
+
+#include <linux/mm.h>
+
+#include <asm/tlbflush.h>
+#include <asm/cacheflush.h>
+#include <asm-generic/tlb.h>
+
+#endif
diff --git a/arch/um/include/asm/tlbflush.h b/arch/um/include/asm/tlbflush.h
new file mode 100644
index 000000000..13a300994
--- /dev/null
+++ b/arch/um/include/asm/tlbflush.h
@@ -0,0 +1,59 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+ */
+
+#ifndef __UM_TLBFLUSH_H
+#define __UM_TLBFLUSH_H
+
+#include <linux/mm.h>
+
+/*
+ * In UML, we need to sync the TLB over by using mmap/munmap syscalls from
+ * the process handling the MM (which can be the kernel itself).
+ *
+ * To track updates, we can hook into set_ptes and flush_tlb_*. With set_ptes
+ * we catch all PTE transitions where memory that was unusable becomes usable.
+ * While with flush_tlb_* we can track any memory that becomes unusable and
+ * even if a higher layer of the page table was modified.
+ *
+ * So, we simply track updates using both methods and mark the memory area to
+ * be synced later on. The only special case is that flush_tlb_kern_* needs to
+ * be executed immediately as there is no good synchronization point in that
+ * case. In contrast, in the set_ptes case we can wait for the next kernel
+ * segfault before we do the synchornization.
+ *
+ *  - flush_tlb_all() flushes all processes TLBs
+ *  - flush_tlb_mm(mm) flushes the specified mm context TLB's
+ *  - flush_tlb_page(vma, vmaddr) flushes one page
+ *  - flush_tlb_range(vma, start, end) flushes a range of pages
+ *  - flush_tlb_kernel_range(start, end) flushes a range of kernel pages
+ */
+
+extern int um_tlb_sync(struct mm_struct *mm);
+
+extern void flush_tlb_all(void);
+extern void flush_tlb_mm(struct mm_struct *mm);
+
+static inline void flush_tlb_page(struct vm_area_struct *vma,
+				  unsigned long address)
+{
+	um_tlb_mark_sync(vma->vm_mm, address, address + PAGE_SIZE);
+}
+
+static inline void flush_tlb_range(struct vm_area_struct *vma,
+				   unsigned long start, unsigned long end)
+{
+	um_tlb_mark_sync(vma->vm_mm, start, end);
+}
+
+static inline void flush_tlb_kernel_range(unsigned long start,
+					  unsigned long end)
+{
+	um_tlb_mark_sync(&init_mm, start, end);
+
+	/* Kernel needs to be synced immediately */
+	um_tlb_sync(&init_mm);
+}
+
+#endif
diff --git a/arch/um/include/asm/uaccess.h b/arch/um/include/asm/uaccess.h
new file mode 100644
index 000000000..4417c8b1d
--- /dev/null
+++ b/arch/um/include/asm/uaccess.h
@@ -0,0 +1,66 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* 
+ * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
+ * Copyright (C) 2015 Richard Weinberger (richard@nod.at)
+ */
+
+#ifndef __UM_UACCESS_H
+#define __UM_UACCESS_H
+
+#include <asm/elf.h>
+#include <linux/unaligned.h>
+#include <sysdep/faultinfo.h>
+
+#define __under_task_size(addr, size) \
+	(((unsigned long) (addr) < TASK_SIZE) && \
+	 (((unsigned long) (addr) + (size)) < TASK_SIZE))
+
+#define __addr_range_nowrap(addr, size) \
+	((unsigned long) (addr) <= ((unsigned long) (addr) + (size)))
+
+extern unsigned long raw_copy_from_user(void *to, const void __user *from, unsigned long n);
+extern unsigned long raw_copy_to_user(void __user *to, const void *from, unsigned long n);
+extern unsigned long __clear_user(void __user *mem, unsigned long len);
+static inline int __access_ok(const void __user *ptr, unsigned long size);
+
+/* Teach asm-generic/uaccess.h that we have C functions for these. */
+#define __access_ok __access_ok
+#define __clear_user __clear_user
+
+#define INLINE_COPY_USER
+
+#include <asm-generic/uaccess.h>
+
+static inline int __access_ok(const void __user *ptr, unsigned long size)
+{
+	unsigned long addr = (unsigned long)ptr;
+	return __addr_range_nowrap(addr, size) && __under_task_size(addr, size);
+}
+
+#define __get_kernel_nofault(dst, src, type, err_label)			\
+do {									\
+	int __faulted;							\
+									\
+	___backtrack_faulted(__faulted);				\
+	if (__faulted) {						\
+		*((type *)dst) = (type) 0;				\
+		goto err_label;						\
+	}								\
+	*((type *)dst) = get_unaligned((type *)(src));			\
+	barrier();							\
+	current->thread.segv_continue = NULL;				\
+} while (0)
+
+#define __put_kernel_nofault(dst, src, type, err_label)			\
+do {									\
+	int __faulted;							\
+									\
+	___backtrack_faulted(__faulted);				\
+	if (__faulted)							\
+		goto err_label;						\
+	put_unaligned(*((type *)src), (type *)(dst));			\
+	barrier();							\
+	current->thread.segv_continue = NULL;				\
+} while (0)
+
+#endif
diff --git a/arch/um/include/asm/unwind.h b/arch/um/include/asm/unwind.h
new file mode 100644
index 000000000..7ffa5437b
--- /dev/null
+++ b/arch/um/include/asm/unwind.h
@@ -0,0 +1,8 @@
+#ifndef _ASM_UML_UNWIND_H
+#define _ASM_UML_UNWIND_H
+
+static inline void
+unwind_module_init(struct module *mod, void *orc_ip, size_t orc_ip_size,
+		   void *orc, size_t orc_size) {}
+
+#endif /* _ASM_UML_UNWIND_H */
diff --git a/arch/um/include/asm/vmalloc.h b/arch/um/include/asm/vmalloc.h
new file mode 100644
index 000000000..9a7b9ed93
--- /dev/null
+++ b/arch/um/include/asm/vmalloc.h
@@ -0,0 +1,4 @@
+#ifndef _ASM_UM_VMALLOC_H
+#define _ASM_UM_VMALLOC_H
+
+#endif /* _ASM_UM_VMALLOC_H */
diff --git a/arch/um/include/asm/vmlinux.lds.h b/arch/um/include/asm/vmlinux.lds.h
new file mode 100644
index 000000000..149494ae7
--- /dev/null
+++ b/arch/um/include/asm/vmlinux.lds.h
@@ -0,0 +1,2 @@
+#include <asm/thread_info.h>
+#include <asm-generic/vmlinux.lds.h>