diff --git a/arch/um/include/os.h b/arch/um/include/os.h
index e11bdcd..688d181 100644
--- a/arch/um/include/os.h
+++ b/arch/um/include/os.h
@@ -300,13 +300,12 @@ 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 r, int w, int x, int phys_fd,
+	       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, int r, int w, int x, int done,
-		   void **data);
+		   unsigned long len, unsigned int prot, int done, void **data);
 
 /* skas/process.c */
 extern int is_skas_winch(int pid, int fd, void *data);
@@ -342,7 +341,6 @@ extern void maybe_sigio_broken(int fd, int read);
 
 /* skas/trap */
 extern void sig_handler_common_skas(int sig, void *sc_ptr);
-extern void user_signal(int sig, union uml_pt_regs *regs, int pid);
 
 /* sys-x86_64/prctl.c */
 extern int os_arch_prctl(int pid, int code, unsigned long *addr);
diff --git a/arch/um/include/tlb.h b/arch/um/include/tlb.h
index 8efc1e0..bcd1a4a 100644
--- a/arch/um/include/tlb.h
+++ b/arch/um/include/tlb.h
@@ -14,9 +14,7 @@ struct host_vm_op {
 		struct {
 			unsigned long addr;
 			unsigned long len;
-			unsigned int r:1;
-			unsigned int w:1;
-			unsigned int x:1;
+			unsigned int prot;
 			int fd;
 			__u64 offset;
 		} mmap;
@@ -27,9 +25,7 @@ struct host_vm_op {
 		struct {
 			unsigned long addr;
 			unsigned long len;
-			unsigned int r:1;
-			unsigned int w:1;
-			unsigned int x:1;
+			unsigned int prot;
 		} mprotect;
 	} u;
 };
diff --git a/arch/um/kernel/physmem.c b/arch/um/kernel/physmem.c
index df1ad3b..3ba6e4c 100644
--- a/arch/um/kernel/physmem.c
+++ b/arch/um/kernel/physmem.c
@@ -21,229 +21,8 @@
 #include "kern.h"
 #include "init.h"
 
-struct phys_desc {
-	struct rb_node rb;
-	int fd;
-	__u64 offset;
-	void *virt;
-	unsigned long phys;
-	struct list_head list;
-};
-
-static struct rb_root phys_mappings = RB_ROOT;
-
-static struct rb_node **find_rb(void *virt)
-{
-	struct rb_node **n = &phys_mappings.rb_node;
-	struct phys_desc *d;
-
-	while(*n != NULL){
-		d = rb_entry(*n, struct phys_desc, rb);
-		if(d->virt == virt)
-			return n;
-
-		if(d->virt > virt)
-			n = &(*n)->rb_left;
-		else
-			n = &(*n)->rb_right;
-	}
-
-	return n;
-}
-
-static struct phys_desc *find_phys_mapping(void *virt)
-{
-	struct rb_node **n = find_rb(virt);
-
-	if(*n == NULL)
-		return NULL;
-
-	return rb_entry(*n, struct phys_desc, rb);
-}
-
-static void insert_phys_mapping(struct phys_desc *desc)
-{
-	struct rb_node **n = find_rb(desc->virt);
-
-	if(*n != NULL)
-		panic("Physical remapping for %p already present",
-		      desc->virt);
-
-	rb_link_node(&desc->rb, rb_parent(*n), n);
-	rb_insert_color(&desc->rb, &phys_mappings);
-}
-
-LIST_HEAD(descriptor_mappings);
-
-struct desc_mapping {
-	int fd;
-	struct list_head list;
-	struct list_head pages;
-};
-
-static struct desc_mapping *find_mapping(int fd)
-{
-	struct desc_mapping *desc;
-	struct list_head *ele;
-
-	list_for_each(ele, &descriptor_mappings){
-		desc = list_entry(ele, struct desc_mapping, list);
-		if(desc->fd == fd)
-			return desc;
-	}
-
-	return NULL;
-}
-
-static struct desc_mapping *descriptor_mapping(int fd)
-{
-	struct desc_mapping *desc;
-
-	desc = find_mapping(fd);
-	if(desc != NULL)
-		return desc;
-
-	desc = kmalloc(sizeof(*desc), GFP_ATOMIC);
-	if(desc == NULL)
-		return NULL;
-
-	*desc = ((struct desc_mapping)
-		{ .fd =		fd,
-		  .list =	LIST_HEAD_INIT(desc->list),
-		  .pages =	LIST_HEAD_INIT(desc->pages) });
-	list_add(&desc->list, &descriptor_mappings);
-
-	return desc;
-}
-
-int physmem_subst_mapping(void *virt, int fd, __u64 offset, int w)
-{
-	struct desc_mapping *fd_maps;
-	struct phys_desc *desc;
-	unsigned long phys;
-	int err;
-
-	fd_maps = descriptor_mapping(fd);
-	if(fd_maps == NULL)
-		return -ENOMEM;
-
-	phys = __pa(virt);
-	desc = find_phys_mapping(virt);
-	if(desc != NULL)
-		panic("Address 0x%p is already substituted\n", virt);
-
-	err = -ENOMEM;
-	desc = kmalloc(sizeof(*desc), GFP_ATOMIC);
-	if(desc == NULL)
-		goto out;
-
-	*desc = ((struct phys_desc)
-		{ .fd =			fd,
-		  .offset =		offset,
-		  .virt =		virt,
-		  .phys =		__pa(virt),
-		  .list = 		LIST_HEAD_INIT(desc->list) });
-	insert_phys_mapping(desc);
-
-	list_add(&desc->list, &fd_maps->pages);
-
-	virt = (void *) ((unsigned long) virt & PAGE_MASK);
-	err = os_map_memory(virt, fd, offset, PAGE_SIZE, 1, w, 0);
-	if(!err)
-		goto out;
-
-	rb_erase(&desc->rb, &phys_mappings);
-	kfree(desc);
- out:
-	return err;
-}
-
 static int physmem_fd = -1;
 
-static void remove_mapping(struct phys_desc *desc)
-{
-	void *virt = desc->virt;
-	int err;
-
-	rb_erase(&desc->rb, &phys_mappings);
-	list_del(&desc->list);
-	kfree(desc);
-
-	err = os_map_memory(virt, physmem_fd, __pa(virt), PAGE_SIZE, 1, 1, 0);
-	if(err)
-		panic("Failed to unmap block device page from physical memory, "
-		      "errno = %d", -err);
-}
-
-int physmem_remove_mapping(void *virt)
-{
-	struct phys_desc *desc;
-
-	virt = (void *) ((unsigned long) virt & PAGE_MASK);
-	desc = find_phys_mapping(virt);
-	if(desc == NULL)
-		return 0;
-
-	remove_mapping(desc);
-	return 1;
-}
-
-void physmem_forget_descriptor(int fd)
-{
-	struct desc_mapping *desc;
-	struct phys_desc *page;
-	struct list_head *ele, *next;
-	__u64 offset;
-	void *addr;
-	int err;
-
-	desc = find_mapping(fd);
-	if(desc == NULL)
-		return;
-
-	list_for_each_safe(ele, next, &desc->pages){
-		page = list_entry(ele, struct phys_desc, list);
-		offset = page->offset;
-		addr = page->virt;
-		remove_mapping(page);
-		err = os_seek_file(fd, offset);
-		if(err)
-			panic("physmem_forget_descriptor - failed to seek "
-			      "to %lld in fd %d, error = %d\n",
-			      offset, fd, -err);
-		err = os_read_file(fd, addr, PAGE_SIZE);
-		if(err < 0)
-			panic("physmem_forget_descriptor - failed to read "
-			      "from fd %d to 0x%p, error = %d\n",
-			      fd, addr, -err);
-	}
-
-	list_del(&desc->list);
-	kfree(desc);
-}
-
-EXPORT_SYMBOL(physmem_forget_descriptor);
-EXPORT_SYMBOL(physmem_remove_mapping);
-EXPORT_SYMBOL(physmem_subst_mapping);
-
-void arch_free_page(struct page *page, int order)
-{
-	void *virt;
-	int i;
-
-	for(i = 0; i < (1 << order); i++){
-		virt = __va(page_to_phys(page + i));
-		physmem_remove_mapping(virt);
-	}
-}
-
-int is_remapped(void *virt)
-{
- 	struct phys_desc *desc = find_phys_mapping(virt);
-
-	return desc != NULL;
-}
-
 /* Changed during early boot */
 unsigned long high_physmem;
 
@@ -350,14 +129,9 @@ void setup_physmem(unsigned long start, unsigned long reserve_end,
 
 int phys_mapping(unsigned long phys, __u64 *offset_out)
 {
-	struct phys_desc *desc = find_phys_mapping(__va(phys & PAGE_MASK));
 	int fd = -1;
 
-	if(desc != NULL){
-		fd = desc->fd;
-		*offset_out = desc->offset;
-	}
-	else if(phys < physmem_size){
+	if(phys < physmem_size){
 		fd = physmem_fd;
 		*offset_out = phys;
 	}
diff --git a/arch/um/kernel/skas/tlb.c b/arch/um/kernel/skas/tlb.c
index c43901a..b3d722d 100644
--- a/arch/um/kernel/skas/tlb.c
+++ b/arch/um/kernel/skas/tlb.c
@@ -27,9 +27,9 @@ static int do_ops(union mm_context *mmu, struct host_vm_op *ops, int last,
 		switch(op->type){
 		case MMAP:
 			ret = map(&mmu->skas.id, op->u.mmap.addr,
-				  op->u.mmap.len, op->u.mmap.r, op->u.mmap.w,
-				  op->u.mmap.x, op->u.mmap.fd,
-				  op->u.mmap.offset, finished, flush);
+				  op->u.mmap.len, op->u.mmap.prot,
+				  op->u.mmap.fd, op->u.mmap.offset, finished,
+				  flush);
 			break;
 		case MUNMAP:
 			ret = unmap(&mmu->skas.id, op->u.munmap.addr,
@@ -37,8 +37,7 @@ static int do_ops(union mm_context *mmu, struct host_vm_op *ops, int last,
 			break;
 		case MPROTECT:
 			ret = protect(&mmu->skas.id, op->u.mprotect.addr,
-				      op->u.mprotect.len, op->u.mprotect.r,
-				      op->u.mprotect.w, op->u.mprotect.x,
+				      op->u.mprotect.len, op->u.mprotect.prot,
 				      finished, flush);
 			break;
 		default:
@@ -102,10 +101,10 @@ void flush_tlb_page_skas(struct vm_area_struct *vma, unsigned long address)
 	pte_t *pte;
 	struct mm_struct *mm = vma->vm_mm;
 	void *flush = NULL;
-	int r, w, x, err = 0;
+	int r, w, x, prot, err = 0;
 	struct mm_id *mm_id;
 
-	pgd = pgd_offset(vma->vm_mm, address);
+	pgd = pgd_offset(mm, address);
 	if(!pgd_present(*pgd))
 		goto kill;
 
@@ -130,19 +129,21 @@ void flush_tlb_page_skas(struct vm_area_struct *vma, unsigned long address)
 	}
 
 	mm_id = &mm->context.skas.id;
+	prot = ((r ? UM_PROT_READ : 0) | (w ? UM_PROT_WRITE : 0) |
+		(x ? UM_PROT_EXEC : 0));
 	if(pte_newpage(*pte)){
 		if(pte_present(*pte)){
 			unsigned long long offset;
 			int fd;
 
 			fd = phys_mapping(pte_val(*pte) & PAGE_MASK, &offset);
-			err = map(mm_id, address, PAGE_SIZE, r, w, x, fd,
-				  offset, 1, &flush);
+			err = map(mm_id, address, PAGE_SIZE, prot, fd, offset,
+				  1, &flush);
 		}
 		else err = unmap(mm_id, address, PAGE_SIZE, 1, &flush);
 	}
 	else if(pte_newprot(*pte))
-		err = protect(mm_id, address, PAGE_SIZE, r, w, x, 1, &flush);
+		err = protect(mm_id, address, PAGE_SIZE, prot, 1, &flush);
 
 	if(err)
 		goto kill;
diff --git a/arch/um/kernel/tlb.c b/arch/um/kernel/tlb.c
index 4a39d50..8a8d528 100644
--- a/arch/um/kernel/tlb.c
+++ b/arch/um/kernel/tlb.c
@@ -17,7 +17,7 @@
 #include "os.h"
 
 static int add_mmap(unsigned long virt, unsigned long phys, unsigned long len,
-		    int r, int w, int x, struct host_vm_op *ops, int *index,
+		    unsigned int prot, struct host_vm_op *ops, int *index,
 		    int last_filled, union mm_context *mmu, void **flush,
 		    int (*do_ops)(union mm_context *, struct host_vm_op *,
 				  int, int, void **))
@@ -31,8 +31,7 @@ static int add_mmap(unsigned long virt, unsigned long phys, unsigned long len,
 		last = &ops[*index];
 		if((last->type == MMAP) &&
 		   (last->u.mmap.addr + last->u.mmap.len == virt) &&
-		   (last->u.mmap.r == r) && (last->u.mmap.w == w) &&
-		   (last->u.mmap.x == x) && (last->u.mmap.fd == fd) &&
+		   (last->u.mmap.prot == prot) && (last->u.mmap.fd == fd) &&
 		   (last->u.mmap.offset + last->u.mmap.len == offset)){
 			last->u.mmap.len += len;
 			return 0;
@@ -48,9 +47,7 @@ static int add_mmap(unsigned long virt, unsigned long phys, unsigned long len,
 			     			.u = { .mmap = {
 						       .addr	= virt,
 						       .len	= len,
-						       .r	= r,
-						       .w	= w,
-						       .x	= x,
+						       .prot	= prot,
 						       .fd	= fd,
 						       .offset	= offset }
 			   } });
@@ -87,8 +84,8 @@ static int add_munmap(unsigned long addr, unsigned long len,
 	return ret;
 }
 
-static int add_mprotect(unsigned long addr, unsigned long len, int r, int w,
-			int x, struct host_vm_op *ops, int *index,
+static int add_mprotect(unsigned long addr, unsigned long len,
+			unsigned int prot, struct host_vm_op *ops, int *index,
 			int last_filled, union mm_context *mmu, void **flush,
 			int (*do_ops)(union mm_context *, struct host_vm_op *,
 				      int, int, void **))
@@ -100,8 +97,7 @@ static int add_mprotect(unsigned long addr, unsigned long len, int r, int w,
 		last = &ops[*index];
 		if((last->type == MPROTECT) &&
 		   (last->u.mprotect.addr + last->u.mprotect.len == addr) &&
-		   (last->u.mprotect.r == r) && (last->u.mprotect.w == w) &&
-		   (last->u.mprotect.x == x)){
+		   (last->u.mprotect.prot == prot)){
 			last->u.mprotect.len += len;
 			return 0;
 		}
@@ -116,9 +112,7 @@ static int add_mprotect(unsigned long addr, unsigned long len, int r, int w,
 			     		       .u = { .mprotect = {
 						       .addr	= addr,
 						       .len	= len,
-						       .r	= r,
-						       .w	= w,
-						       .x	= x } } });
+						       .prot	= prot } } });
 	return ret;
 }
 
@@ -133,7 +127,7 @@ static inline int update_pte_range(pmd_t *pmd, unsigned long addr,
 						 void **))
 {
 	pte_t *pte;
-	int r, w, x, ret = 0;
+	int r, w, x, prot, ret = 0;
 
 	pte = pte_offset_kernel(pmd, addr);
 	do {
@@ -146,19 +140,19 @@ static inline int update_pte_range(pmd_t *pmd, unsigned long addr,
 		} else if (!pte_dirty(*pte)) {
 			w = 0;
 		}
+		prot = ((r ? UM_PROT_READ : 0) | (w ? UM_PROT_WRITE : 0) |
+			(x ? UM_PROT_EXEC : 0));
 		if(force || pte_newpage(*pte)){
 			if(pte_present(*pte))
 				ret = add_mmap(addr, pte_val(*pte) & PAGE_MASK,
-					       PAGE_SIZE, r, w, x, ops,
-					       op_index, last_op, mmu, flush,
-					       do_ops);
+					       PAGE_SIZE, prot, ops, op_index,
+					       last_op, mmu, flush, do_ops);
 			else ret = add_munmap(addr, PAGE_SIZE, ops, op_index,
 					      last_op, mmu, flush, do_ops);
 		}
 		else if(pte_newprot(*pte))
-			ret = add_mprotect(addr, PAGE_SIZE, r, w, x, ops,
-					   op_index, last_op, mmu, flush,
-					   do_ops);
+			ret = add_mprotect(addr, PAGE_SIZE, prot, ops, op_index,
+					   last_op, mmu, flush, do_ops);
 		*pte = pte_mkuptodate(*pte);
 	} while (pte++, addr += PAGE_SIZE, ((addr != end) && !ret));
 	return ret;
@@ -377,14 +371,6 @@ pte_t *addr_pte(struct task_struct *task, unsigned long addr)
 	return(pte_offset_map(pmd, addr));
 }
 
-void flush_tlb_page(struct vm_area_struct *vma, unsigned long address)
-{
-	address &= PAGE_MASK;
-
-	CHOOSE_MODE(flush_tlb_range(vma, address, address + PAGE_SIZE),
-		    flush_tlb_page_skas(vma, address));
-}
-
 void flush_tlb_all(void)
 {
 	flush_tlb_mm(current->mm);
diff --git a/arch/um/os-Linux/skas/mem.c b/arch/um/os-Linux/skas/mem.c
index af07907..8e490ff 100644
--- a/arch/um/os-Linux/skas/mem.c
+++ b/arch/um/os-Linux/skas/mem.c
@@ -24,10 +24,11 @@
 #include "uml-config.h"
 #include "sysdep/ptrace.h"
 #include "sysdep/stub.h"
+#include "init.h"
 
 extern unsigned long batch_syscall_stub, __syscall_stub_start;
 
-extern void wait_stub_done(int pid, int sig, char * fname);
+extern void wait_stub_done(int pid);
 
 static inline unsigned long *check_init_stack(struct mm_id * mm_idp,
 					      unsigned long *stack)
@@ -39,6 +40,19 @@ static inline unsigned long *check_init_stack(struct mm_id * mm_idp,
 	return stack;
 }
 
+static unsigned long syscall_regs[MAX_REG_NR];
+
+static int __init init_syscall_regs(void)
+{
+	get_safe_registers(syscall_regs, NULL);
+	syscall_regs[REGS_IP_INDEX] = UML_CONFIG_STUB_CODE +
+		((unsigned long) &batch_syscall_stub -
+		 (unsigned long) &__syscall_stub_start);
+	return 0;
+}
+
+__initcall(init_syscall_regs);
+
 extern int proc_mm;
 
 int single_count = 0;
@@ -47,12 +61,11 @@ int multi_op_count = 0;
 
 static inline long do_syscall_stub(struct mm_id * mm_idp, void **addr)
 {
-	unsigned long regs[MAX_REG_NR];
 	int n, i;
 	long ret, offset;
 	unsigned long * data;
 	unsigned long * syscall;
-	int pid = mm_idp->u.pid;
+	int err, pid = mm_idp->u.pid;
 
 	if(proc_mm)
 #warning Need to look up userspace_pid by cpu
@@ -60,21 +73,21 @@ static inline long do_syscall_stub(struct mm_id * mm_idp, void **addr)
 
 	multi_count++;
 
-	get_safe_registers(regs, NULL);
-	regs[REGS_IP_INDEX] = UML_CONFIG_STUB_CODE +
-		((unsigned long) &batch_syscall_stub -
-		 (unsigned long) &__syscall_stub_start);
-
-	n = ptrace_setregs(pid, regs);
+	n = ptrace_setregs(pid, syscall_regs);
 	if(n < 0){
 		printk("Registers - \n");
 		for(i = 0; i < MAX_REG_NR; i++)
-			printk("\t%d\t0x%lx\n", i, regs[i]);
+			printk("\t%d\t0x%lx\n", i, syscall_regs[i]);
 		panic("do_syscall_stub : PTRACE_SETREGS failed, errno = %d\n",
 		      -n);
 	}
 
-	wait_stub_done(pid, 0, "do_syscall_stub");
+	err = ptrace(PTRACE_CONT, pid, 0, 0);
+	if(err)
+		panic("Failed to continue stub, pid = %d, errno = %d\n", pid,
+		      errno);
+
+	wait_stub_done(pid);
 
 	/* When the stub stops, we find the following values on the
 	 * beginning of the stack:
@@ -176,14 +189,10 @@ long syscall_stub_data(struct mm_id * mm_idp,
 	return 0;
 }
 
-int map(struct mm_id * mm_idp, unsigned long virt, unsigned long len,
-	int r, int w, int x, int phys_fd, unsigned long long offset,
-	int done, void **data)
+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)
 {
-	int prot, ret;
-
-	prot = (r ? PROT_READ : 0) | (w ? PROT_WRITE : 0) |
-		(x ? PROT_EXEC : 0);
+	int ret;
 
 	if(proc_mm){
 		struct proc_mm_op map;
@@ -253,13 +262,11 @@ int unmap(struct mm_id * mm_idp, unsigned long addr, unsigned long len,
 }
 
 int protect(struct mm_id * mm_idp, unsigned long addr, unsigned long len,
-	    int r, int w, int x, int done, void **data)
+	    unsigned int prot, int done, void **data)
 {
 	struct proc_mm_op protect;
-	int prot, ret;
+	int ret;
 
-	prot = (r ? PROT_READ : 0) | (w ? PROT_WRITE : 0) |
-		(x ? PROT_EXEC : 0);
 	if(proc_mm){
 		int fd = mm_idp->u.mm_fd;
 
diff --git a/arch/um/os-Linux/skas/process.c b/arch/um/os-Linux/skas/process.c
index 1f39f2b..5c088a5 100644
--- a/arch/um/os-Linux/skas/process.c
+++ b/arch/um/os-Linux/skas/process.c
@@ -34,6 +34,7 @@
 #include "process.h"
 #include "longjmp.h"
 #include "kern_constants.h"
+#include "as-layout.h"
 
 int is_skas_winch(int pid, int fd, void *data)
 {
@@ -60,37 +61,42 @@ static int ptrace_dump_regs(int pid)
         return 0;
 }
 
-void wait_stub_done(int pid, int sig, char * fname)
+/*
+ * Signals that are OK to receive in the stub - we'll just continue it.
+ * SIGWINCH will happen when UML is inside a detached screen.
+ */
+#define STUB_SIG_MASK ((1 << SIGVTALRM) | (1 << SIGWINCH))
+
+/* Signals that the stub will finish with - anything else is an error */
+#define STUB_DONE_MASK ((1 << SIGUSR1) | (1 << SIGTRAP))
+
+void wait_stub_done(int pid)
 {
 	int n, status, err;
 
-	do {
-		if ( sig != -1 ) {
-			err = ptrace(PTRACE_CONT, pid, 0, sig);
-			if(err)
-				panic("%s : continue failed, errno = %d\n",
-				      fname, errno);
-		}
-		sig = 0;
-
+	while(1){
 		CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED));
-	} while((n >= 0) && WIFSTOPPED(status) &&
-	        ((WSTOPSIG(status) == SIGVTALRM) ||
-		 /* running UML inside a detached screen can cause
-		  * SIGWINCHes
-		  */
-		 (WSTOPSIG(status) == SIGWINCH)));
-
-	if((n < 0) || !WIFSTOPPED(status) ||
-	   (WSTOPSIG(status) != SIGUSR1 && WSTOPSIG(status) != SIGTRAP)){
-		err = ptrace_dump_regs(pid);
+		if((n < 0) || !WIFSTOPPED(status))
+			goto bad_wait;
+
+		if(((1 << WSTOPSIG(status)) & STUB_SIG_MASK) == 0)
+			break;
+
+		err = ptrace(PTRACE_CONT, pid, 0, 0);
 		if(err)
-			printk("Failed to get registers from stub, "
-			       "errno = %d\n", -err);
-		panic("%s : failed to wait for SIGUSR1/SIGTRAP, "
-		      "pid = %d, n = %d, errno = %d, status = 0x%x\n",
-		      fname, pid, n, errno, status);
+			panic("wait_stub_done : continue failed, errno = %d\n",
+			      errno);
 	}
+
+	if(((1 << WSTOPSIG(status)) & STUB_DONE_MASK) != 0)
+		return;
+
+bad_wait:
+	err = ptrace_dump_regs(pid);
+	if(err)
+		printk("Failed to get registers from stub, errno = %d\n", -err);
+	panic("wait_stub_done : failed to wait for SIGUSR1/SIGTRAP, pid = %d, "
+	      "n = %d, errno = %d, status = 0x%x\n", pid, n, errno, status);
 }
 
 extern unsigned long current_stub_stack(void);
@@ -112,7 +118,11 @@ void get_skas_faultinfo(int pid, struct faultinfo * fi)
 			       sizeof(struct ptrace_faultinfo));
 	}
 	else {
-		wait_stub_done(pid, SIGSEGV, "get_skas_faultinfo");
+		err = ptrace(PTRACE_CONT, pid, 0, SIGSEGV);
+		if(err)
+			panic("Failed to continue stub, pid = %d, errno = %d\n",
+			      pid, errno);
+		wait_stub_done(pid);
 
 		/* faultinfo is prepared by the stub-segv-handler at start of
 		 * the stub stack page. We just have to copy it.
@@ -304,10 +314,13 @@ void userspace(union uml_pt_regs *regs)
 		UPT_SYSCALL_NR(regs) = -1; /* Assume: It's not a syscall */
 
 		if(WIFSTOPPED(status)){
-		  	switch(WSTOPSIG(status)){
+			int sig = WSTOPSIG(status);
+		  	switch(sig){
 			case SIGSEGV:
-				if(PTRACE_FULL_FAULTINFO || !ptrace_faultinfo)
-					user_signal(SIGSEGV, regs, pid);
+				if(PTRACE_FULL_FAULTINFO || !ptrace_faultinfo){
+					get_skas_faultinfo(pid, &regs->skas.faultinfo);
+					(*sig_info[SIGSEGV])(SIGSEGV, regs);
+				}
 				else handle_segv(pid, regs);
 				break;
 			case SIGTRAP + 0x80:
@@ -322,11 +335,13 @@ void userspace(union uml_pt_regs *regs)
 			case SIGBUS:
 			case SIGFPE:
 			case SIGWINCH:
-				user_signal(WSTOPSIG(status), regs, pid);
+				block_signals();
+				(*sig_info[sig])(sig, regs);
+				unblock_signals();
 				break;
 			default:
 			        printk("userspace - child stopped with signal "
-				       "%d\n", WSTOPSIG(status));
+				       "%d\n", sig);
 			}
 			pid = userspace_pid[0];
 			interrupt_end();
@@ -338,11 +353,29 @@ void userspace(union uml_pt_regs *regs)
 	}
 }
 
+static unsigned long thread_regs[MAX_REG_NR];
+static unsigned long thread_fp_regs[HOST_FP_SIZE];
+
+static int __init init_thread_regs(void)
+{
+	get_safe_registers(thread_regs, thread_fp_regs);
+	/* Set parent's instruction pointer to start of clone-stub */
+	thread_regs[REGS_IP_INDEX] = UML_CONFIG_STUB_CODE +
+				(unsigned long) stub_clone_handler -
+				(unsigned long) &__syscall_stub_start;
+	thread_regs[REGS_SP_INDEX] = UML_CONFIG_STUB_DATA + PAGE_SIZE -
+		sizeof(void *);
+#ifdef __SIGNAL_FRAMESIZE
+	thread_regs[REGS_SP_INDEX] -= __SIGNAL_FRAMESIZE;
+#endif
+	return 0;
+}
+
+__initcall(init_thread_regs);
+
 int copy_context_skas0(unsigned long new_stack, int pid)
 {
 	int err;
-	unsigned long regs[MAX_REG_NR];
-	unsigned long fp_regs[HOST_FP_SIZE];
 	unsigned long current_stack = current_stub_stack();
 	struct stub_data *data = (struct stub_data *) current_stack;
 	struct stub_data *child_data = (struct stub_data *) new_stack;
@@ -357,23 +390,12 @@ int copy_context_skas0(unsigned long new_stack, int pid)
 				      .timer    = ((struct itimerval)
 					            { { 0, 1000000 / hz() },
 						      { 0, 1000000 / hz() }})});
-	get_safe_registers(regs, fp_regs);
-
-	/* Set parent's instruction pointer to start of clone-stub */
-	regs[REGS_IP_INDEX] = UML_CONFIG_STUB_CODE +
-				(unsigned long) stub_clone_handler -
-				(unsigned long) &__syscall_stub_start;
-	regs[REGS_SP_INDEX] = UML_CONFIG_STUB_DATA + PAGE_SIZE -
-		sizeof(void *);
-#ifdef __SIGNAL_FRAMESIZE
-	regs[REGS_SP_INDEX] -= __SIGNAL_FRAMESIZE;
-#endif
-	err = ptrace_setregs(pid, regs);
+	err = ptrace_setregs(pid, thread_regs);
 	if(err < 0)
 		panic("copy_context_skas0 : PTRACE_SETREGS failed, "
 		      "pid = %d, errno = %d\n", pid, -err);
 
-	err = ptrace_setfpregs(pid, fp_regs);
+	err = ptrace_setfpregs(pid, thread_fp_regs);
 	if(err < 0)
 		panic("copy_context_skas0 : PTRACE_SETFPREGS failed, "
 		      "pid = %d, errno = %d\n", pid, -err);
@@ -384,7 +406,11 @@ int copy_context_skas0(unsigned long new_stack, int pid)
 	/* Wait, until parent has finished its work: read child's pid from
 	 * parent's stack, and check, if bad result.
 	 */
-	wait_stub_done(pid, 0, "copy_context_skas0");
+	err = ptrace(PTRACE_CONT, pid, 0, 0);
+	if(err)
+		panic("Failed to continue new process, pid = %d, "
+		      "errno = %d\n", pid, errno);
+	wait_stub_done(pid);
 
 	pid = data->err;
 	if(pid < 0)
@@ -394,7 +420,7 @@ int copy_context_skas0(unsigned long new_stack, int pid)
 	/* Wait, until child has finished too: read child's result from
 	 * child's stack and check it.
 	 */
-	wait_stub_done(pid, -1, "copy_context_skas0");
+	wait_stub_done(pid);
 	if (child_data->err != UML_CONFIG_STUB_DATA)
 		panic("copy_context_skas0 - stub-child reports error %ld\n",
 		      child_data->err);
diff --git a/arch/um/os-Linux/skas/trap.c b/arch/um/os-Linux/skas/trap.c
index 5110eff..3b600c2 100644
--- a/arch/um/os-Linux/skas/trap.c
+++ b/arch/um/os-Linux/skas/trap.c
@@ -64,20 +64,3 @@ void sig_handler_common_skas(int sig, void *sc_ptr)
 	errno = save_errno;
 	r->skas.is_user = save_user;
 }
-
-extern int ptrace_faultinfo;
-
-void user_signal(int sig, union uml_pt_regs *regs, int pid)
-{
-	void (*handler)(int, union uml_pt_regs *);
-	int segv = ((sig == SIGFPE) || (sig == SIGSEGV) || (sig == SIGBUS) ||
-		    (sig == SIGILL) || (sig == SIGTRAP));
-
-	if (segv)
-		get_skas_faultinfo(pid, &regs->skas.faultinfo);
-
-	handler = sig_info[sig];
-	handler(sig, (union uml_pt_regs *) regs);
-
-	unblock_signals();
-}
diff --git a/arch/um/sys-i386/user-offsets.c b/arch/um/sys-i386/user-offsets.c
index ee42c27..29118cf 100644
--- a/arch/um/sys-i386/user-offsets.c
+++ b/arch/um/sys-i386/user-offsets.c
@@ -1,9 +1,10 @@
 #include <stdio.h>
+#include <stddef.h>
 #include <signal.h>
+#include <sys/poll.h>
+#include <sys/mman.h>
 #include <asm/ptrace.h>
 #include <asm/user.h>
-#include <stddef.h>
-#include <sys/poll.h>
 
 #define DEFINE(sym, val) \
 	asm volatile("\n->" #sym " %0 " #val : : "i" (val))
@@ -72,4 +73,8 @@ void foo(void)
 	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/um/sys-x86_64/user-offsets.c b/arch/um/sys-x86_64/user-offsets.c
index 7bb5325..0d5fd76 100644
--- a/arch/um/sys-x86_64/user-offsets.c
+++ b/arch/um/sys-x86_64/user-offsets.c
@@ -2,6 +2,7 @@
 #include <stddef.h>
 #include <signal.h>
 #include <sys/poll.h>
+#include <sys/mman.h>
 #define __FRAME_OFFSETS
 #include <asm/ptrace.h>
 #include <asm/types.h>
@@ -93,4 +94,8 @@ void foo(void)
 	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/include/asm-um/page.h b/include/asm-um/page.h
index 4296d31..8e310d8 100644
--- a/include/asm-um/page.h
+++ b/include/asm-um/page.h
@@ -114,9 +114,6 @@ extern unsigned long uml_physmem;
 extern struct page *arch_validate(struct page *page, gfp_t mask, int order);
 #define HAVE_ARCH_VALIDATE
 
-extern void arch_free_page(struct page *page, int order);
-#define HAVE_ARCH_FREE_PAGE
-
 #include <asm-generic/memory_model.h>
 #include <asm-generic/page.h>
 
diff --git a/include/asm-um/tlbflush.h b/include/asm-um/tlbflush.h
index 522aa30..e78c28c 100644
--- a/include/asm-um/tlbflush.h
+++ b/include/asm-um/tlbflush.h
@@ -7,6 +7,7 @@
 #define __UM_TLBFLUSH_H
 
 #include <linux/mm.h>
+#include "choose-mode.h"
 
 /*
  * TLB flushing:
@@ -24,6 +25,18 @@ extern void flush_tlb_all(void);
 extern void flush_tlb_mm(struct mm_struct *mm);
 extern void flush_tlb_range(struct vm_area_struct *vma, unsigned long start, 
 			    unsigned long end);
+extern void flush_tlb_page_skas(struct vm_area_struct *vma,
+				unsigned long address);
+
+static inline void flush_tlb_page(struct vm_area_struct *vma,
+				  unsigned long address)
+{
+	address &= PAGE_MASK;
+
+	CHOOSE_MODE(flush_tlb_range(vma, address, address + PAGE_SIZE),
+		    flush_tlb_page_skas(vma, address));
+}
+
 extern void flush_tlb_page(struct vm_area_struct *vma, unsigned long vmaddr);
 extern void flush_tlb_kernel_vm(void);
 extern void flush_tlb_kernel_range(unsigned long start, unsigned long end);
@@ -35,14 +48,3 @@ static inline void flush_tlb_pgtables(struct mm_struct *mm,
 }
 
 #endif
-
-/*
- * Overrides for Emacs so that we follow Linus's tabbing style.
- * Emacs will notice this stuff at the end of the file and automatically
- * adjust the settings for this buffer only.  This must remain at the end
- * of the file.
- * ---------------------------------------------------------------------------
- * Local variables:
- * c-file-style: "linux"
- * End:
- */