21 files changed, 207 insertions, 302 deletions

diff --git a/arch/um/include/shared/arch.h b/arch/um/include/shared/arch.h
index 880ee42a3329..cc398a21ad96 100644
--- a/arch/um/include/shared/arch.h
+++ b/arch/um/include/shared/arch.h
@@ -12,4 +12,6 @@ extern void arch_check_bugs(void);
 extern int arch_fixup(unsigned long address, struct uml_pt_regs *regs);
 extern void arch_examine_signal(int sig, struct uml_pt_regs *regs);
 
+void mc_set_rip(void *_mc, void *target);
+
 #endif
diff --git a/arch/um/include/shared/as-layout.h b/arch/um/include/shared/as-layout.h
index 9a0bd648d872..02ef258e3395 100644
--- a/arch/um/include/shared/as-layout.h
+++ b/arch/um/include/shared/as-layout.h
@@ -23,36 +23,34 @@
 #define STUB_START stub_start
 #define STUB_CODE STUB_START
 #define STUB_DATA (STUB_CODE + UM_KERN_PAGE_SIZE)
-#define STUB_END (STUB_DATA + UM_KERN_PAGE_SIZE)
+#define STUB_DATA_PAGES 2
+#define STUB_SIZE ((1 + STUB_DATA_PAGES) * UM_KERN_PAGE_SIZE)
+#define STUB_END (STUB_START + STUB_SIZE)
 
-#ifndef __ASSEMBLY__
+#ifndef __ASSEMBLER__
 
 #include <sysdep/ptrace.h>
 
-struct cpu_task {
-	int pid;
-	void *task;
-};
+struct task_struct;
+extern struct task_struct *cpu_tasks[];
 
-extern struct cpu_task cpu_tasks[];
+extern unsigned long long physmem_size;
 
 extern unsigned long high_physmem;
 extern unsigned long uml_physmem;
 extern unsigned long uml_reserved;
 extern unsigned long end_vm;
 extern unsigned long start_vm;
-extern unsigned long long highmem;
 
 extern unsigned long brk_start;
 
-extern unsigned long host_task_size;
 extern unsigned long stub_start;
 
-extern int linux_main(int argc, char **argv);
+extern int linux_main(int argc, char **argv, char **envp);
 extern void uml_finishsetup(void);
 
 struct siginfo;
-extern void (*sig_info[])(int, struct siginfo *si, struct uml_pt_regs *);
+extern void (*sig_info[])(int, struct siginfo *si, struct uml_pt_regs *, void *);
 
 #endif
 
diff --git a/arch/um/include/shared/common-offsets.h b/arch/um/include/shared/common-offsets.h
deleted file mode 100644
index 96195483fbd0..000000000000
--- a/arch/um/include/shared/common-offsets.h
+++ /dev/null
@@ -1,36 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-/* for use by sys-$SUBARCH/kernel-offsets.c */
-#include <stub-data.h>
-
-DEFINE(KERNEL_MADV_REMOVE, MADV_REMOVE);
-
-DEFINE(UM_KERN_PAGE_SIZE, PAGE_SIZE);
-DEFINE(UM_KERN_PAGE_MASK, PAGE_MASK);
-DEFINE(UM_KERN_PAGE_SHIFT, PAGE_SHIFT);
-DEFINE(UM_NSEC_PER_SEC, NSEC_PER_SEC);
-
-DEFINE(UM_GFP_KERNEL, GFP_KERNEL);
-DEFINE(UM_GFP_ATOMIC, GFP_ATOMIC);
-
-DEFINE(UM_THREAD_SIZE, THREAD_SIZE);
-
-DEFINE(UM_NSEC_PER_SEC, NSEC_PER_SEC);
-DEFINE(UM_NSEC_PER_USEC, NSEC_PER_USEC);
-
-#ifdef CONFIG_PRINTK
-DEFINE(UML_CONFIG_PRINTK, CONFIG_PRINTK);
-#endif
-#ifdef CONFIG_UML_X86
-DEFINE(UML_CONFIG_UML_X86, CONFIG_UML_X86);
-#endif
-#ifdef CONFIG_64BIT
-DEFINE(UML_CONFIG_64BIT, CONFIG_64BIT);
-#endif
-#ifdef CONFIG_UML_TIME_TRAVEL_SUPPORT
-DEFINE(UML_CONFIG_UML_TIME_TRAVEL_SUPPORT, CONFIG_UML_TIME_TRAVEL_SUPPORT);
-#endif
-
-/* for stub */
-DEFINE(UML_STUB_FIELD_OFFSET, offsetof(struct stub_data, offset));
-DEFINE(UML_STUB_FIELD_CHILD_ERR, offsetof(struct stub_data, child_err));
-DEFINE(UML_STUB_FIELD_FD, offsetof(struct stub_data, fd));
diff --git a/arch/um/include/shared/irq_kern.h b/arch/um/include/shared/irq_kern.h
index f2dc817abb7c..44357fa6ee29 100644
--- a/arch/um/include/shared/irq_kern.h
+++ b/arch/um/include/shared/irq_kern.h
@@ -76,4 +76,5 @@ static inline bool um_irq_timetravel_handler_used(void)
 }
 
 void um_free_irq(int irq, void *dev_id);
+void free_irqs(void);
 #endif
diff --git a/arch/um/include/shared/irq_user.h b/arch/um/include/shared/irq_user.h
index da0f6eea30d0..746abc24a5d5 100644
--- a/arch/um/include/shared/irq_user.h
+++ b/arch/um/include/shared/irq_user.h
@@ -15,7 +15,10 @@ enum um_irq_type {
 };
 
 struct siginfo;
-extern void sigio_handler(int sig, struct siginfo *unused_si, struct uml_pt_regs *regs);
+extern void sigio_handler(int sig, struct siginfo *unused_si,
+			  struct uml_pt_regs *regs, void *mc);
+extern void sigchld_handler(int sig, struct siginfo *unused_si,
+			   struct uml_pt_regs *regs, void *mc);
 void sigio_run_timetravel_handlers(void);
 extern void free_irq_by_fd(int fd);
 extern void deactivate_fd(int fd, int irqnum);
diff --git a/arch/um/include/shared/kern_util.h b/arch/um/include/shared/kern_util.h
index d8b8b4f07e42..38321188c04c 100644
--- a/arch/um/include/shared/kern_util.h
+++ b/arch/um/include/shared/kern_util.h
@@ -13,28 +13,25 @@ struct siginfo;
 
 extern int uml_exitcode;
 
-extern int ncpus;
 extern int kmalloc_ok;
 
-#define UML_ROUND_UP(addr) \
-	((((unsigned long) addr) + PAGE_SIZE - 1) & PAGE_MASK)
-
 extern unsigned long alloc_stack(int order, int atomic);
 extern void free_stack(unsigned long stack, int order);
 
 struct pt_regs;
 extern void do_signal(struct pt_regs *regs);
 extern void interrupt_end(void);
-extern void relay_signal(int sig, struct siginfo *si, struct uml_pt_regs *regs);
+extern void relay_signal(int sig, struct siginfo *si, struct uml_pt_regs *regs,
+			 void *mc);
 
 extern unsigned long segv(struct faultinfo fi, unsigned long ip,
-			  int is_user, struct uml_pt_regs *regs);
+			  int is_user, struct uml_pt_regs *regs,
+			  void *mc);
 extern int handle_page_fault(unsigned long address, unsigned long ip,
 			     int is_write, int is_user, int *code_out);
 
 extern unsigned int do_IRQ(int irq, struct uml_pt_regs *regs);
 extern void initial_thread_cb(void (*proc)(void *), void *arg);
-extern int is_syscall(unsigned long addr);
 
 extern void timer_handler(int sig, struct siginfo *unused_si, struct uml_pt_regs *regs);
 
@@ -50,21 +47,25 @@ extern void do_uml_exitcalls(void);
  * Are we disallowed to sleep? Used to choose between GFP_KERNEL and
  * GFP_ATOMIC.
  */
-extern int __cant_sleep(void);
+extern int __uml_cant_sleep(void);
 extern int get_current_pid(void);
 extern int copy_from_user_proc(void *to, void *from, int size);
 extern char *uml_strdup(const char *string);
+int uml_need_resched(void);
 
 extern unsigned long to_irq_stack(unsigned long *mask_out);
 extern unsigned long from_irq_stack(int nested);
 
-extern int singlestepping(void *t);
+extern int singlestepping(void);
 
-extern void segv_handler(int sig, struct siginfo *unused_si, struct uml_pt_regs *regs);
-extern void bus_handler(int sig, struct siginfo *si, struct uml_pt_regs *regs);
-extern void winch(int sig, struct siginfo *unused_si, struct uml_pt_regs *regs);
+extern void segv_handler(int sig, struct siginfo *unused_si, struct uml_pt_regs *regs,
+			 void *mc);
+extern void winch(int sig, struct siginfo *unused_si, struct uml_pt_regs *regs,
+		  void *mc);
 extern void fatal_sigsegv(void) __attribute__ ((noreturn));
 
 void um_idle_sleep(void);
 
+void kasan_map_memory(void *start, size_t len);
+
 #endif
diff --git a/arch/um/include/shared/longjmp.h b/arch/um/include/shared/longjmp.h
index 8863319039f3..c53e43d980c8 100644
--- a/arch/um/include/shared/longjmp.h
+++ b/arch/um/include/shared/longjmp.h
@@ -5,7 +5,6 @@
 #include <sysdep/archsetjmp.h>
 #include <os.h>
 
-extern int signals_enabled;
 extern int setjmp(jmp_buf);
 extern void longjmp(jmp_buf, int);
 
@@ -15,7 +14,7 @@ extern void longjmp(jmp_buf, int);
 
 #define UML_SETJMP(buf) ({				\
 	int n, enable;					\
-	enable = *(volatile int *)&signals_enabled;	\
+	enable = um_get_signals();			\
 	n = setjmp(*buf);				\
 	if(n != 0)					\
 		um_set_signals_trace(enable);		\
diff --git a/arch/um/include/shared/mem_user.h b/arch/um/include/shared/mem_user.h
index 11a723a58545..8a5b72872ff8 100644
--- a/arch/um/include/shared/mem_user.h
+++ b/arch/um/include/shared/mem_user.h
@@ -32,25 +32,10 @@
 #ifndef _MEM_USER_H
 #define _MEM_USER_H
 
-struct iomem_region {
-	struct iomem_region *next;
-	char *driver;
-	int fd;
-	int size;
-	unsigned long phys;
-	unsigned long virt;
-};
-
-extern struct iomem_region *iomem_regions;
-extern int iomem_size;
-
 #define ROUND_4M(n) ((((unsigned long) (n)) + (1 << 22)) & ~((1 << 22) - 1))
 
-extern unsigned long find_iomem(char *driver, unsigned long *len_out);
-extern void mem_total_pages(unsigned long physmem, unsigned long iomem,
-		     unsigned long highmem);
 extern void setup_physmem(unsigned long start, unsigned long usable,
-			  unsigned long len, unsigned long long highmem);
+			  unsigned long len);
 extern void map_memory(unsigned long virt, unsigned long phys,
 		       unsigned long len, int r, int w, int x);
 
diff --git a/arch/um/include/shared/net_kern.h b/arch/um/include/shared/net_kern.h
deleted file mode 100644
index 67b2e9a1f2e5..000000000000
--- a/arch/um/include/shared/net_kern.h
+++ /dev/null
@@ -1,69 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-/*
- * Copyright (C) 2002 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
- */
-
-#ifndef __UM_NET_KERN_H
-#define __UM_NET_KERN_H
-
-#include <linux/netdevice.h>
-#include <linux/platform_device.h>
-#include <linux/skbuff.h>
-#include <linux/socket.h>
-#include <linux/list.h>
-#include <linux/workqueue.h>
-
-struct uml_net {
-	struct list_head list;
-	struct net_device *dev;
-	struct platform_device pdev;
-	int index;
-};
-
-struct uml_net_private {
-	struct list_head list;
-	spinlock_t lock;
-	struct net_device *dev;
-	struct timer_list tl;
-
-	struct work_struct work;
-	int fd;
-	unsigned char mac[ETH_ALEN];
-	int max_packet;
-	unsigned short (*protocol)(struct sk_buff *);
-	int (*open)(void *);
-	void (*close)(int, void *);
-	void (*remove)(void *);
-	int (*read)(int, struct sk_buff *skb, struct uml_net_private *);
-	int (*write)(int, struct sk_buff *skb, struct uml_net_private *);
-
-	void (*add_address)(unsigned char *, unsigned char *, void *);
-	void (*delete_address)(unsigned char *, unsigned char *, void *);
-	char user[];
-};
-
-struct net_kern_info {
-	void (*init)(struct net_device *, void *);
-	unsigned short (*protocol)(struct sk_buff *);
-	int (*read)(int, struct sk_buff *skb, struct uml_net_private *);
-	int (*write)(int, struct sk_buff *skb, struct uml_net_private *);
-};
-
-struct transport {
-	struct list_head list;
-	const char *name;
-	int (* const setup)(char *, char **, void *);
-	const struct net_user_info *user;
-	const struct net_kern_info *kern;
-	const int private_size;
-	const int setup_size;
-};
-
-extern int tap_setup_common(char *str, char *type, char **dev_name,
-			    char **mac_out, char **gate_addr);
-extern void register_transport(struct transport *new);
-extern unsigned short eth_protocol(struct sk_buff *skb);
-extern void uml_net_setup_etheraddr(struct net_device *dev, char *str);
-
-
-#endif
diff --git a/arch/um/include/shared/net_user.h b/arch/um/include/shared/net_user.h
deleted file mode 100644
index ba92a4d93531..000000000000
--- a/arch/um/include/shared/net_user.h
+++ /dev/null
@@ -1,52 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-/*
- * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
- */
-
-#ifndef __UM_NET_USER_H__
-#define __UM_NET_USER_H__
-
-#define ETH_ADDR_LEN (6)
-#define ETH_HEADER_ETHERTAP (16)
-#define ETH_HEADER_OTHER (26) /* 14 for ethernet + VLAN + MPLS for crazy people */
-#define ETH_MAX_PACKET (1500)
-
-#define UML_NET_VERSION (4)
-
-struct net_user_info {
-	int (*init)(void *, void *);
-	int (*open)(void *);
-	void (*close)(int, void *);
-	void (*remove)(void *);
-	void (*add_address)(unsigned char *, unsigned char *, void *);
-	void (*delete_address)(unsigned char *, unsigned char *, void *);
-	int max_packet;
-	int mtu;
-};
-
-extern void iter_addresses(void *d, void (*cb)(unsigned char *,
-					       unsigned char *, void *),
-			   void *arg);
-
-extern void *get_output_buffer(int *len_out);
-extern void free_output_buffer(void *buffer);
-
-extern int tap_open_common(void *dev, char *gate_addr);
-extern void tap_check_ips(char *gate_addr, unsigned char *eth_addr);
-
-extern void read_output(int fd, char *output_out, int len);
-
-extern int net_read(int fd, void *buf, int len);
-extern int net_recvfrom(int fd, void *buf, int len);
-extern int net_write(int fd, void *buf, int len);
-extern int net_send(int fd, void *buf, int len);
-extern int net_sendto(int fd, void *buf, int len, void *to, int sock_len);
-
-extern void open_addr(unsigned char *addr, unsigned char *netmask, void *arg);
-extern void close_addr(unsigned char *addr, unsigned char *netmask, void *arg);
-
-extern char *split_if_spec(char *str, ...);
-
-extern int dev_netmask(void *d, void *m);
-
-#endif
diff --git a/arch/um/include/shared/os.h b/arch/um/include/shared/os.h
index 0df646c6651e..b26e94292fc1 100644
--- a/arch/um/include/shared/os.h
+++ b/arch/um/include/shared/os.h
@@ -143,9 +143,7 @@ extern int os_access(const char *file, int mode);
 extern int os_set_exec_close(int fd);
 extern int os_ioctl_generic(int fd, unsigned int cmd, unsigned long arg);
 extern int os_get_ifname(int fd, char *namebuf);
-extern int os_set_slip(int fd);
 extern int os_mode_fd(int fd, int mode);
-extern int os_fsync_file(int fd);
 
 extern int os_seek_file(int fd, unsigned long long offset);
 extern int os_open_file(const char *file, struct openflags flags, int mode);
@@ -163,8 +161,10 @@ extern int os_set_fd_block(int fd, int blocking);
 extern int os_accept_connection(int fd);
 extern int os_create_unix_socket(const char *file, int len, int close_on_exec);
 extern int os_shutdown_socket(int fd, int r, int w);
+extern int os_dup_file(int fd);
 extern void os_close_file(int fd);
-extern int os_rcv_fd(int fd, int *helper_pid_out);
+ssize_t os_rcv_fd_msg(int fd, int *fds, unsigned int n_fds,
+		      void *data, size_t data_len);
 extern int os_connect_socket(const char *name);
 extern int os_file_type(char *file);
 extern int os_file_mode(const char *file, struct openflags *mode_out);
@@ -179,6 +179,8 @@ extern int os_eventfd(unsigned int initval, int flags);
 extern int os_sendmsg_fds(int fd, const void *buf, unsigned int len,
 			  const int *fds, unsigned int fds_num);
 int os_poll(unsigned int n, const int *fds);
+void *os_mmap_rw_shared(int fd, size_t size);
+void *os_mremap_rw_shared(void *old_addr, size_t old_size, size_t new_size);
 
 /* start_up.c */
 extern void os_early_checks(void);
@@ -191,16 +193,16 @@ extern void get_host_cpu_features(
 /* mem.c */
 extern int create_mem_file(unsigned long long len);
 
+/* tlb.c */
+extern void report_enomem(void);
+
 /* process.c */
-extern unsigned long os_process_pc(int pid);
-extern int os_process_parent(int pid);
+pid_t os_reap_child(void);
 extern void os_alarm_process(int pid);
-extern void os_stop_process(int pid);
 extern void os_kill_process(int pid, int reap_child);
 extern void os_kill_ptraced_process(int pid, int reap_child);
 
 extern int os_getpid(void);
-extern int os_getpgrp(void);
 
 extern void init_new_thread_signals(void);
 
@@ -211,7 +213,11 @@ extern int os_protect_memory(void *addr, unsigned long len,
 extern int os_unmap_memory(void *addr, int len);
 extern int os_drop_memory(void *addr, int length);
 extern int can_drop_memory(void);
-extern int os_mincore(void *addr, unsigned long len);
+
+void os_set_pdeathsig(void);
+
+int os_futex_wait(void *uaddr, unsigned int val);
+int os_futex_wake(void *uaddr);
 
 /* execvp.c */
 extern int execvp_noalloc(char *buf, const char *file, char *const argv[]);
@@ -221,6 +227,11 @@ extern int run_helper_thread(int (*proc)(void *), void *arg,
 			     unsigned int flags, unsigned long *stack_out);
 extern int helper_wait(int pid);
 
+struct os_helper_thread;
+int os_run_helper_thread(struct os_helper_thread **td_out,
+			 void *(*routine)(void *), void *arg);
+void os_kill_helper_thread(struct os_helper_thread *td);
+void os_fix_helper_thread_signals(void);
 
 /* umid.c */
 extern int umid_file_name(char *name, char *buf, int len);
@@ -235,9 +246,9 @@ extern void send_sigio_to_self(void);
 extern int change_sig(int signal, int on);
 extern void block_signals(void);
 extern void unblock_signals(void);
+extern int um_get_signals(void);
 extern int um_set_signals(int enable);
 extern int um_set_signals_trace(int enable);
-extern int os_is_signal_stack(void);
 extern void deliver_alarm(void);
 extern void register_pm_wake_signal(void);
 extern void block_signals_hard(void);
@@ -259,34 +270,29 @@ extern void os_warn(const char *fmt, ...)
 	__attribute__ ((format (printf, 1, 2)));
 
 /* time.c */
+void os_idle_prepare(void);
 extern void os_idle_sleep(void);
 extern int os_timer_create(void);
-extern int os_timer_set_interval(unsigned long long nsecs);
-extern int os_timer_one_shot(unsigned long long nsecs);
-extern void os_timer_disable(void);
+extern int os_timer_set_interval(int cpu, unsigned long long nsecs);
+extern int os_timer_one_shot(int cpu, unsigned long long nsecs);
+extern void os_timer_disable(int cpu);
 extern long long os_persistent_clock_emulation(void);
 extern long long os_nsecs(void);
 
 /* skas/mem.c */
-extern long run_syscall_stub(struct mm_id * mm_idp,
-			     int syscall, unsigned long *args, long expected,
-			     void **addr, int done);
-extern long syscall_stub_data(struct mm_id * mm_idp,
-			      unsigned long *data, int data_count,
-			      void **addr, void **stub_addr);
-extern int map(struct mm_id * mm_idp, unsigned long virt,
-	       unsigned long len, int prot, int phys_fd,
-	       unsigned long long offset, int done, void **data);
-extern int unmap(struct mm_id * mm_idp, unsigned long addr, unsigned long len,
-		 int done, void **data);
-extern int protect(struct mm_id * mm_idp, unsigned long addr,
-		   unsigned long len, unsigned int prot, int done, void **data);
+int syscall_stub_flush(struct mm_id *mm_idp);
+struct stub_syscall *syscall_stub_alloc(struct mm_id *mm_idp);
+void syscall_stub_dump_error(struct mm_id *mm_idp);
+
+int map(struct mm_id *mm_idp, unsigned long virt,
+	unsigned long len, int prot, int phys_fd,
+	unsigned long long offset);
+int unmap(struct mm_id *mm_idp, unsigned long addr, unsigned long len);
 
 /* skas/process.c */
 extern int is_skas_winch(int pid, int fd, void *data);
-extern int start_userspace(unsigned long stub_stack);
-extern int copy_context_skas0(unsigned long stack, int pid);
-extern void userspace(struct uml_pt_regs *regs, unsigned long *aux_fp_regs);
+extern int start_userspace(struct mm_id *mm_id);
+extern void userspace(struct uml_pt_regs *regs);
 extern void new_thread(void *stack, jmp_buf *buf, void (*handler)(void));
 extern void switch_threads(jmp_buf *me, jmp_buf *you);
 extern int start_idle_thread(void *stack, jmp_buf *switch_buf);
@@ -313,7 +319,7 @@ extern void um_irqs_resume(void);
 extern int add_sigio_fd(int fd);
 extern int ignore_sigio_fd(int fd);
 extern void maybe_sigio_broken(int fd);
-extern void sigio_broken(int fd);
+extern void sigio_broken(void);
 /*
  * unlocked versions for IRQ controller code.
  *
@@ -323,15 +329,9 @@ extern void sigio_broken(int fd);
 extern int __add_sigio_fd(int fd);
 extern int __ignore_sigio_fd(int fd);
 
-/* prctl.c */
-extern int os_arch_prctl(int pid, int option, unsigned long *arg2);
-
 /* tty.c */
 extern int get_pty(void);
 
-/* sys-$ARCH/task_size.c */
-extern unsigned long os_get_top_address(void);
-
 long syscall(long number, ...);
 
 /* irqflags tracing */
@@ -343,4 +343,17 @@ extern void um_trace_signals_off(void);
 /* time-travel */
 extern void deliver_time_travel_irqs(void);
 
+/* smp.c */
+#if IS_ENABLED(CONFIG_SMP)
+void os_init_smp(void);
+int os_start_cpu_thread(int cpu);
+void os_start_secondary(void *arg, jmp_buf *switch_buf);
+int os_send_ipi(int cpu, int vector);
+void os_local_ipi_enable(void);
+void os_local_ipi_disable(void);
+#else /* !CONFIG_SMP */
+static inline void os_local_ipi_enable(void) { }
+static inline void os_local_ipi_disable(void) { }
+#endif /* CONFIG_SMP */
+
 #endif
diff --git a/arch/um/include/shared/ptrace_user.h b/arch/um/include/shared/ptrace_user.h
index 95455e8996e7..8a705d8f96ce 100644
--- a/arch/um/include/shared/ptrace_user.h
+++ b/arch/um/include/shared/ptrace_user.h
@@ -12,45 +12,4 @@
 extern int ptrace_getregs(long pid, unsigned long *regs_out);
 extern int ptrace_setregs(long pid, unsigned long *regs_in);
 
-/* syscall emulation path in ptrace */
-
-#ifndef PTRACE_SYSEMU
-#define PTRACE_SYSEMU 31
-#endif
-#ifndef PTRACE_SYSEMU_SINGLESTEP
-#define PTRACE_SYSEMU_SINGLESTEP 32
-#endif
-
-/* On architectures, that started to support PTRACE_O_TRACESYSGOOD
- * in linux 2.4, there are two different definitions of
- * PTRACE_SETOPTIONS: linux 2.4 uses 21 while linux 2.6 uses 0x4200.
- * For binary compatibility, 2.6 also supports the old "21", named
- * PTRACE_OLDSETOPTION. On these architectures, UML always must use
- * "21", to ensure the kernel runs on 2.4 and 2.6 host without
- * recompilation. So, we use PTRACE_OLDSETOPTIONS in UML.
- * We also want to be able to build the kernel on 2.4, which doesn't
- * have PTRACE_OLDSETOPTIONS. So, if it is missing, we declare
- * PTRACE_OLDSETOPTIONS to be the same as PTRACE_SETOPTIONS.
- *
- * On architectures, that start to support PTRACE_O_TRACESYSGOOD on
- * linux 2.6, PTRACE_OLDSETOPTIONS never is defined, and also isn't
- * supported by the host kernel. In that case, our trick lets us use
- * the new 0x4200 with the name PTRACE_OLDSETOPTIONS.
- */
-#ifndef PTRACE_OLDSETOPTIONS
-#define PTRACE_OLDSETOPTIONS PTRACE_SETOPTIONS
-#endif
-
-void set_using_sysemu(int value);
-int get_using_sysemu(void);
-extern int sysemu_supported;
-
-#define SELECT_PTRACE_OPERATION(sysemu_mode, singlestep_mode) \
-	(((int[3][3] ) { \
-		{ PTRACE_SYSCALL, PTRACE_SYSCALL, PTRACE_SINGLESTEP }, \
-		{ PTRACE_SYSEMU, PTRACE_SYSEMU, PTRACE_SINGLESTEP }, \
-		{ PTRACE_SYSEMU, PTRACE_SYSEMU_SINGLESTEP, \
-		  PTRACE_SYSEMU_SINGLESTEP } }) \
-		[sysemu_mode][singlestep_mode])
-
 #endif
diff --git a/arch/um/include/shared/registers.h b/arch/um/include/shared/registers.h
index 2f9c3ce5b45e..7d81b2339a48 100644
--- a/arch/um/include/shared/registers.h
+++ b/arch/um/include/shared/registers.h
@@ -8,14 +8,6 @@
 
 #include <sysdep/ptrace.h>
 
-extern int save_i387_registers(int pid, unsigned long *fp_regs);
-extern int restore_i387_registers(int pid, unsigned long *fp_regs);
-extern int save_fp_registers(int pid, unsigned long *fp_regs);
-extern int restore_fp_registers(int pid, unsigned long *fp_regs);
-extern int save_fpx_registers(int pid, unsigned long *fp_regs);
-extern int restore_fpx_registers(int pid, unsigned long *fp_regs);
-extern int save_registers(int pid, struct uml_pt_regs *regs);
-extern int restore_pid_registers(int pid, struct uml_pt_regs *regs);
 extern int init_pid_registers(int pid);
 extern void get_safe_registers(unsigned long *regs, unsigned long *fp_regs);
 extern int get_fp_registers(int pid, unsigned long *regs);
diff --git a/arch/um/include/shared/sigio.h b/arch/um/include/shared/sigio.h
index e60c8b227844..c6c2edce1f6d 100644
--- a/arch/um/include/shared/sigio.h
+++ b/arch/um/include/shared/sigio.h
@@ -6,7 +6,6 @@
 #ifndef __SIGIO_H__
 #define __SIGIO_H__
 
-extern int write_sigio_irq(int fd);
 extern void sigio_lock(void);
 extern void sigio_unlock(void);
 
diff --git a/arch/um/include/shared/skas/mm_id.h b/arch/um/include/shared/skas/mm_id.h
index e82e203f5f41..fb96c0bd8222 100644
--- a/arch/um/include/shared/skas/mm_id.h
+++ b/arch/um/include/shared/skas/mm_id.h
@@ -6,13 +6,24 @@
 #ifndef __MM_ID_H
 #define __MM_ID_H
 
+#include <linux/compiler_types.h>
+
+#define STUB_MAX_FDS 4
+
 struct mm_id {
-	union {
-		int mm_fd;
-		int pid;
-	} u;
+	int pid;
 	unsigned long stack;
-	int kill;
+	int syscall_data_len;
+
+	/* Only used with SECCOMP mode */
+	int sock;
+	int syscall_fd_num;
+	int syscall_fd_map[STUB_MAX_FDS];
 };
 
+void enter_turnstile(struct mm_id *mm_id) __acquires(turnstile);
+void exit_turnstile(struct mm_id *mm_id) __releases(turnstile);
+
+void notify_mm_kill(int pid);
+
 #endif
diff --git a/arch/um/include/shared/skas/skas.h b/arch/um/include/shared/skas/skas.h
index c93d2cbc8f32..2237ffedec75 100644
--- a/arch/um/include/shared/skas/skas.h
+++ b/arch/um/include/shared/skas/skas.h
@@ -8,12 +8,14 @@
 
 #include <sysdep/ptrace.h>
 
-extern int userspace_pid[];
+extern int using_seccomp;
 
-extern int user_thread(unsigned long stack, int flags);
 extern void new_thread_handler(void);
 extern void handle_syscall(struct uml_pt_regs *regs);
-extern long execute_syscall_skas(void *r);
 extern unsigned long current_stub_stack(void);
+extern struct mm_id *current_mm_id(void);
+extern void current_mm_sync(void);
+void initial_jmpbuf_lock(void);
+void initial_jmpbuf_unlock(void);
 
 #endif
diff --git a/arch/um/include/shared/skas/stub-data.h b/arch/um/include/shared/skas/stub-data.h
index 5e3ade3fb38b..27db38e95df9 100644
--- a/arch/um/include/shared/skas/stub-data.h
+++ b/arch/um/include/shared/skas/stub-data.h
@@ -8,10 +8,69 @@
 #ifndef __STUB_DATA_H
 #define __STUB_DATA_H
 
+#include <linux/compiler_types.h>
+#include <as-layout.h>
+#include <sysdep/tls.h>
+#include <sysdep/stub-data.h>
+#include <mm_id.h>
+
+#define FUTEX_IN_CHILD 0
+#define FUTEX_IN_KERN 1
+
+struct stub_init_data {
+	int seccomp;
+
+	unsigned long stub_start;
+
+	int stub_code_fd;
+	unsigned long stub_code_offset;
+	int stub_data_fd;
+	unsigned long stub_data_offset;
+
+	unsigned long signal_handler;
+	unsigned long signal_restorer;
+};
+
+#define STUB_NEXT_SYSCALL(s) \
+	((struct stub_syscall *) (((unsigned long) s) + (s)->cmd_len))
+
+enum stub_syscall_type {
+	STUB_SYSCALL_UNSET = 0,
+	STUB_SYSCALL_MMAP,
+	STUB_SYSCALL_MUNMAP,
+};
+
+struct stub_syscall {
+	struct {
+		unsigned long addr;
+		unsigned long length;
+		unsigned long offset;
+		int fd;
+		int prot;
+	} mem;
+
+	enum stub_syscall_type syscall;
+};
+
 struct stub_data {
-	unsigned long offset;
-	int fd;
-	long parent_err, child_err;
+	long err;
+
+	int syscall_data_len;
+	/* 128 leaves enough room for additional fields in the struct */
+	struct stub_syscall syscall_data[(UM_KERN_PAGE_SIZE - 128) / sizeof(struct stub_syscall)] __aligned(16);
+
+	/* data shared with signal handler (only used in seccomp mode) */
+	short restart_wait;
+	unsigned int futex;
+	int signal;
+	unsigned short si_offset;
+	unsigned short mctx_offset;
+
+	/* seccomp architecture specific state restore */
+	struct stub_data_arch arch_data;
+
+	/* Stack for our signal handlers and for calling into . */
+	unsigned char sigstack[UM_KERN_PAGE_SIZE] __aligned(UM_KERN_PAGE_SIZE);
 };
 
 #endif
diff --git a/arch/um/include/shared/smp.h b/arch/um/include/shared/smp.h
new file mode 100644
index 000000000000..06e3faa95091
--- /dev/null
+++ b/arch/um/include/shared/smp.h
@@ -0,0 +1,20 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __UM_SHARED_SMP_H
+#define __UM_SHARED_SMP_H
+
+#if IS_ENABLED(CONFIG_SMP)
+
+extern int uml_ncpus;
+
+int uml_curr_cpu(void);
+void uml_start_secondary(void *opaque);
+void uml_ipi_handler(int vector);
+
+#else /* !CONFIG_SMP */
+
+#define uml_ncpus 1
+#define uml_curr_cpu() 0
+
+#endif /* CONFIG_SMP */
+
+#endif /* __UM_SHARED_SMP_H */
diff --git a/arch/um/include/shared/timetravel.h b/arch/um/include/shared/timetravel.h
index e5c3d69f1b69..7c2b277b7eb0 100644
--- a/arch/um/include/shared/timetravel.h
+++ b/arch/um/include/shared/timetravel.h
@@ -12,11 +12,19 @@ enum time_travel_mode {
 	TT_MODE_EXTERNAL,
 };
 
-#if defined(UML_CONFIG_UML_TIME_TRAVEL_SUPPORT) || \
-    defined(CONFIG_UML_TIME_TRAVEL_SUPPORT)
+#if IS_ENABLED(CONFIG_UML_TIME_TRAVEL_SUPPORT)
 extern enum time_travel_mode time_travel_mode;
+extern int time_travel_should_print_bc_msg;
 #else
 #define time_travel_mode TT_MODE_OFF
-#endif /* (UML_)CONFIG_UML_TIME_TRAVEL_SUPPORT */
+#define time_travel_should_print_bc_msg 0
+#endif /* CONFIG_UML_TIME_TRAVEL_SUPPORT */
+
+void _time_travel_print_bc_msg(void);
+static inline void time_travel_print_bc_msg(void)
+{
+	if (time_travel_should_print_bc_msg)
+		_time_travel_print_bc_msg();
+}
 
 #endif /* _UM_TIME_TRAVEL_H_ */
diff --git a/arch/um/include/shared/um_malloc.h b/arch/um/include/shared/um_malloc.h
index 13da93284c2c..815dd03e8707 100644
--- a/arch/um/include/shared/um_malloc.h
+++ b/arch/um/include/shared/um_malloc.h
@@ -11,8 +11,9 @@
 extern void *uml_kmalloc(int size, int flags);
 extern void kfree(const void *ptr);
 
-extern void *vmalloc(unsigned long size);
-extern void vfree(void *ptr);
+extern void *vmalloc_noprof(unsigned long size);
+#define vmalloc(...)		vmalloc_noprof(__VA_ARGS__)
+extern void vfree(const void *ptr);
 
 #endif /* __UM_MALLOC_H__ */
 
diff --git a/arch/um/include/shared/user.h b/arch/um/include/shared/user.h
index bda66e5a9d4e..139eb78a4767 100644
--- a/arch/um/include/shared/user.h
+++ b/arch/um/include/shared/user.h
@@ -38,20 +38,29 @@ extern void panic(const char *fmt, ...)
 #define UM_KERN_DEBUG	KERN_DEBUG
 #define UM_KERN_CONT	KERN_CONT
 
-#ifdef UML_CONFIG_PRINTK
+#if IS_ENABLED(CONFIG_PRINTK)
 #define printk(...) _printk(__VA_ARGS__)
 extern int _printk(const char *fmt, ...)
 	__attribute__ ((format (printf, 1, 2)));
+extern void print_hex_dump(const char *level, const char *prefix_str,
+			   int prefix_type, int rowsize, int groupsize,
+			   const void *buf, size_t len, _Bool ascii);
 #else
 static inline int printk(const char *fmt, ...)
 {
 	return 0;
 }
+static inline void print_hex_dump(const char *level, const char *prefix_str,
+				  int prefix_type, int rowsize, int groupsize,
+				  const void *buf, size_t len, _Bool ascii)
+{
+}
 #endif
 
 extern int in_aton(char *str);
-extern size_t strlcpy(char *, const char *, size_t);
 extern size_t strlcat(char *, const char *, size_t);
+extern size_t sized_strscpy(char *, const char *, size_t);
+#define strscpy(dst, src)	sized_strscpy(dst, src, sizeof(dst))
 
 /* Copied from linux/compiler-gcc.h since we can't include it directly */
 #define barrier() __asm__ __volatile__("": : :"memory")