--- ./arch/i386/kernel/sys_i386.c.skas	2004-03-13 17:55:23.000000000 +0100
+++ ./arch/i386/kernel/sys_i386.c	2004-06-17 16:24:30.000000000 +0200
@@ -41,7 +41,7 @@
 }
 
 /* common code for old and new mmaps */
-static inline long do_mmap2(
+long do_mmap2(struct mm_struct *mm,
 	unsigned long addr, unsigned long len,
 	unsigned long prot, unsigned long flags,
 	unsigned long fd, unsigned long pgoff)
@@ -56,9 +56,9 @@
 			goto out;
 	}
 
-	down_write(&current->mm->mmap_sem);
-	error = do_mmap_pgoff(file, addr, len, prot, flags, pgoff);
-	up_write(&current->mm->mmap_sem);
+	down_write(&mm->mmap_sem);
+	error = __do_mmap_pgoff(mm, file, addr, len, prot, flags, pgoff);
+	up_write(&mm->mmap_sem);
 
 	if (file)
 		fput(file);
@@ -70,7 +70,7 @@
 	unsigned long prot, unsigned long flags,
 	unsigned long fd, unsigned long pgoff)
 {
-	return do_mmap2(addr, len, prot, flags, fd, pgoff);
+	return do_mmap2(current->mm, addr, len, prot, flags, fd, pgoff);
 }
 
 /*
@@ -101,7 +101,7 @@
 	if (a.offset & ~PAGE_MASK)
 		goto out;
 
-	err = do_mmap2(a.addr, a.len, a.prot, a.flags, a.fd, a.offset >> PAGE_SHIFT);
+	err = do_mmap2(current->mm, a.addr, a.len, a.prot, a.flags, a.fd, a.offset >> PAGE_SHIFT);
 out:
 	return err;
 }
--- ./arch/i386/kernel/ptrace.c.skas	2004-06-16 22:25:18.000000000 +0200
+++ ./arch/i386/kernel/ptrace.c	2004-06-17 16:24:30.000000000 +0200
@@ -15,6 +15,7 @@
 #include <linux/user.h>
 #include <linux/security.h>
 #include <linux/audit.h>
+#include <linux/proc_mm.h>
 
 #include <asm/uaccess.h>
 #include <asm/pgtable.h>
@@ -509,6 +510,56 @@
 					(struct user_desc __user *) data);
 		break;
 
+#ifdef CONFIG_PROC_MM
+	case PTRACE_FAULTINFO: {
+		struct ptrace_faultinfo fault;
+
+		fault = ((struct ptrace_faultinfo) 
+			{ .is_write	= child->thread.error_code,
+			  .addr		= child->thread.cr2 });
+		ret = copy_to_user((unsigned long *) data, &fault, 
+				   sizeof(fault));
+		if(ret)
+			break;
+		break;
+	}
+
+	case PTRACE_SIGPENDING:
+		ret = copy_to_user((unsigned long *) data, 
+				   &child->pending.signal,
+				   sizeof(child->pending.signal));
+		break;
+
+	case PTRACE_LDT: {
+		struct ptrace_ldt ldt;
+
+		if(copy_from_user(&ldt, (unsigned long *) data, 
+				  sizeof(ldt))){
+			ret = -EIO;
+			break;
+		}
+		ret = modify_ldt(child->mm, ldt.func, ldt.ptr, ldt.bytecount);
+		break;
+	}
+
+	case PTRACE_SWITCH_MM: {
+		struct mm_struct *old = child->mm;
+		struct mm_struct *new = proc_mm_get_mm(data);
+
+		if(IS_ERR(new)){
+			ret = PTR_ERR(new);
+			break;
+		}
+
+		atomic_inc(&new->mm_users);
+		child->mm = new;
+		child->active_mm = new;
+		mmput(old);
+		ret = 0;
+		break;
+	}
+#endif
+
 	default:
 		ret = ptrace_request(child, request, addr, data);
 		break;
--- ./arch/i386/kernel/ldt.c.skas	2003-12-25 19:23:56.000000000 +0100
+++ ./arch/i386/kernel/ldt.c	2004-06-17 16:24:30.000000000 +0200
@@ -54,7 +54,7 @@
 	pc->size = mincount;
 	wmb();
 
-	if (reload) {
+	if (reload && (&current->active_mm->context == pc)) {
 #ifdef CONFIG_SMP
 		cpumask_t mask;
 		preempt_disable();
@@ -89,14 +89,12 @@
  * we do not have to muck with descriptors here, that is
  * done in switch_mm() as needed.
  */
-int init_new_context(struct task_struct *tsk, struct mm_struct *mm)
+int __init_new_context(struct mm_struct *mm, struct mm_struct *old_mm)
 {
-	struct mm_struct * old_mm;
 	int retval = 0;
 
 	init_MUTEX(&mm->context.sem);
 	mm->context.size = 0;
-	old_mm = current->mm;
 	if (old_mm && old_mm->context.size > 0) {
 		down(&old_mm->context.sem);
 		retval = copy_ldt(&mm->context, &old_mm->context);
@@ -105,6 +103,11 @@
 	return retval;
 }
 
+int init_new_context(struct task_struct *tsk, struct mm_struct *mm)
+{
+	return __init_new_context(mm, current->mm);
+}
+
 /*
  * No need to lock the MM as we are the last user
  */
@@ -121,11 +124,11 @@
 	}
 }
 
-static int read_ldt(void __user * ptr, unsigned long bytecount)
+static int read_ldt(struct mm_struct * mm, void __user * ptr,
+		    unsigned long bytecount)
 {
 	int err;
 	unsigned long size;
-	struct mm_struct * mm = current->mm;
 
 	if (!mm->context.size)
 		return 0;
@@ -169,9 +172,8 @@
 	return err;
 }
 
-static int write_ldt(void __user * ptr, unsigned long bytecount, int oldmode)
+static int write_ldt(struct mm_struct * mm, void __user * ptr, unsigned long bytecount, int oldmode)
 {
-	struct mm_struct * mm = current->mm;
 	__u32 entry_1, entry_2, *lp;
 	int error;
 	struct user_desc ldt_info;
@@ -195,7 +197,7 @@
 
 	down(&mm->context.sem);
 	if (ldt_info.entry_number >= mm->context.size) {
-		error = alloc_ldt(&current->mm->context, ldt_info.entry_number+1, 1);
+		error = alloc_ldt(&mm->context, ldt_info.entry_number+1, 1);
 		if (error < 0)
 			goto out_unlock;
 	}
@@ -228,23 +230,29 @@
 	return error;
 }
 
-asmlinkage int sys_modify_ldt(int func, void __user *ptr, unsigned long bytecount)
+int modify_ldt(struct mm_struct * mm, int func, void __user *ptr,
+	       unsigned long bytecount)
 {
 	int ret = -ENOSYS;
 
 	switch (func) {
 	case 0:
-		ret = read_ldt(ptr, bytecount);
+		ret = read_ldt(mm, ptr, bytecount);
 		break;
 	case 1:
-		ret = write_ldt(ptr, bytecount, 1);
+		ret = write_ldt(mm, ptr, bytecount, 1);
 		break;
 	case 2:
 		ret = read_default_ldt(ptr, bytecount);
 		break;
 	case 0x11:
-		ret = write_ldt(ptr, bytecount, 0);
+		ret = write_ldt(mm, ptr, bytecount, 0);
 		break;
 	}
 	return ret;
 }
+
+asmlinkage int sys_modify_ldt(int func, void __user *ptr, unsigned long bytecount)
+{
+	return modify_ldt(current->mm, func, ptr, bytecount);
+}
--- ./arch/i386/Kconfig.skas	2004-06-16 22:25:18.000000000 +0200
+++ ./arch/i386/Kconfig	2004-06-17 16:24:30.000000000 +0200
@@ -720,6 +720,10 @@
 	depends on HIGHMEM64G
 	default y
 
+config PROC_MM
+	bool "/proc/mm support"
+	default y
+
 # Common NUMA Features
 config NUMA
 	bool "Numa Memory Allocation and Scheduler Support"
--- ./include/linux/mm.h.skas	2004-06-16 22:27:11.000000000 +0200
+++ ./include/linux/mm.h	2004-06-17 16:24:30.000000000 +0200
@@ -574,6 +574,9 @@
 extern struct shrinker *set_shrinker(int, shrinker_t);
 extern void remove_shrinker(struct shrinker *shrinker);
 
+extern long do_mprotect(struct mm_struct *mm, unsigned long start, 
+			size_t len, unsigned long prot);
+
 /*
  * On a two-level page table, this ends up being trivial. Thus the
  * inlining and the symmetry break with pte_alloc_map() that does all
@@ -632,9 +635,15 @@
 
 extern unsigned long get_unmapped_area(struct file *, unsigned long, unsigned long, unsigned long, unsigned long);
 
-extern unsigned long do_mmap_pgoff(struct file *file, unsigned long addr,
+extern unsigned long __do_mmap_pgoff(struct mm_struct *mm, struct file *file, 
+				   unsigned long addr, unsigned long len,
+				   unsigned long prot, unsigned long flag,
+				   unsigned long pgoff);
+static inline unsigned long do_mmap_pgoff(struct file *file, unsigned long addr,
 	unsigned long len, unsigned long prot,
-	unsigned long flag, unsigned long pgoff);
+	unsigned long flag, unsigned long pgoff) {
+	return __do_mmap_pgoff(current->mm, file, addr, len, prot, flag, pgoff);
+}
 
 static inline unsigned long do_mmap(struct file *file, unsigned long addr,
 	unsigned long len, unsigned long prot,
--- ./include/linux/proc_mm.h.skas	2004-06-17 16:24:30.000000000 +0200
+++ ./include/linux/proc_mm.h	2004-06-17 16:24:30.000000000 +0200
@@ -0,0 +1,48 @@
+/* 
+ * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
+ * Licensed under the GPL
+ */
+
+#ifndef __PROC_MM_H
+#define __PROC_MM_H
+
+#include "linux/sched.h"
+
+#define MM_MMAP 54
+#define MM_MUNMAP 55
+#define MM_MPROTECT 56
+#define MM_COPY_SEGMENTS 57
+
+struct mm_mmap {
+	unsigned long addr;
+	unsigned long len;
+	unsigned long prot;
+	unsigned long flags;
+	unsigned long fd;
+	unsigned long offset;
+};
+
+struct mm_munmap {
+	unsigned long addr;
+	unsigned long len;	
+};
+
+struct mm_mprotect {
+	unsigned long addr;
+	unsigned long len;
+        unsigned int prot;
+};
+
+struct proc_mm_op {
+	int op;
+	union {
+		struct mm_mmap mmap;
+		struct mm_munmap munmap;
+	        struct mm_mprotect mprotect;
+		int copy_segments;
+	} u;
+};
+
+extern struct mm_struct *proc_mm_get_mm(int fd);
+
+#endif
--- ./include/asm-i386/desc.h.skas	2003-12-20 17:44:08.000000000 +0100
+++ ./include/asm-i386/desc.h	2004-06-17 16:24:30.000000000 +0200
@@ -123,6 +123,9 @@
 	put_cpu();
 }
 
+extern int modify_ldt(struct mm_struct * mm, int func, void __user *ptr,
+		      unsigned long bytecount);
+
 #endif /* !__ASSEMBLY__ */
 
 #endif
--- ./include/asm-i386/processor.h.skas	2004-06-16 22:27:00.000000000 +0200
+++ ./include/asm-i386/processor.h	2004-06-17 16:24:30.000000000 +0200
@@ -649,6 +649,8 @@
 
 extern void select_idle_routine(const struct cpuinfo_x86 *c);
 
+extern int __init_new_context(struct mm_struct *mm, struct mm_struct *old_mm);
+
 #define cache_line_size() (boot_cpu_data.x86_cache_alignment)
 
 #ifdef CONFIG_SCHED_SMT
--- ./include/asm-i386/ptrace.h.skas	2003-12-20 17:21:33.000000000 +0100
+++ ./include/asm-i386/ptrace.h	2004-06-17 16:24:30.000000000 +0200
@@ -59,4 +59,26 @@
 #define instruction_pointer(regs) ((regs)->eip)
 #endif
 
+/*For SKAS3 support.*/
+#ifndef _LINUX_PTRACE_STRUCT_DEF
+#define _LINUX_PTRACE_STRUCT_DEF
+
+#define PTRACE_FAULTINFO	  52
+#define PTRACE_SIGPENDING	  53
+#define PTRACE_LDT		  54
+#define PTRACE_SWITCH_MM 	  55
+
+struct ptrace_faultinfo {
+	int is_write;
+	unsigned long addr;
+};
+
+struct ptrace_ldt {
+	int func;
+  	void *ptr;
+	unsigned long bytecount;
+};
+
+#endif /*ifndef _LINUX_PTRACE_STRUCT_DEF*/
+
 #endif
--- ./include/asm-i386/mmu_context.h.skas	2003-12-25 19:24:24.000000000 +0100
+++ ./include/asm-i386/mmu_context.h	2004-06-17 16:24:30.000000000 +0200
@@ -29,6 +29,10 @@
 {
 	int cpu = smp_processor_id();
 
+#ifdef CONFIG_SMP
+	prev = cpu_tlbstate[cpu].active_mm;
+#endif
+
 	if (likely(prev != next)) {
 		/* stop flush ipis for the previous mm */
 		cpu_clear(cpu, prev->cpu_vm_mask);
@@ -50,7 +54,6 @@
 #ifdef CONFIG_SMP
 	else {
 		cpu_tlbstate[cpu].state = TLBSTATE_OK;
-		BUG_ON(cpu_tlbstate[cpu].active_mm != next);
 
 		if (!cpu_test_and_set(cpu, next->cpu_vm_mask)) {
 			/* We were in lazy tlb mode and leave_mm disabled 
--- ./mm/mmap.c.skas	2004-06-16 22:27:18.000000000 +0200
+++ ./mm/mmap.c	2004-06-17 16:24:30.000000000 +0200
@@ -725,11 +725,11 @@
  * The caller must hold down_write(current->mm->mmap_sem).
  */
 
-unsigned long do_mmap_pgoff(struct file * file, unsigned long addr,
-			unsigned long len, unsigned long prot,
-			unsigned long flags, unsigned long pgoff)
+unsigned long __do_mmap_pgoff(struct mm_struct *mm, struct file * file, 
+			    unsigned long addr, unsigned long len,
+			    unsigned long prot, unsigned long flags,
+			    unsigned long pgoff)
 {
-	struct mm_struct * mm = current->mm;
 	struct vm_area_struct * vma, * prev;
 	struct inode *inode;
 	unsigned int vm_flags;
@@ -988,7 +988,7 @@
 	return error;
 }
 
-EXPORT_SYMBOL(do_mmap_pgoff);
+EXPORT_SYMBOL(__do_mmap_pgoff);
 
 /* Get an address range which is currently unmapped.
  * For shmat() with addr=0.
--- ./mm/mprotect.c.skas	2004-06-16 22:27:18.000000000 +0200
+++ ./mm/mprotect.c	2004-06-17 16:24:30.000000000 +0200
@@ -185,8 +185,9 @@
 	return error;
 }
 
-asmlinkage long
-sys_mprotect(unsigned long start, size_t len, unsigned long prot)
+long
+do_mprotect(struct mm_struct *mm, unsigned long start, size_t len, 
+	     unsigned long prot)
 {
 	unsigned long vm_flags, nstart, end, tmp;
 	struct vm_area_struct *vma, *prev;
@@ -209,9 +210,9 @@
 
 	vm_flags = calc_vm_prot_bits(prot);
 
-	down_write(&current->mm->mmap_sem);
+	down_write(&mm->mmap_sem);
 
-	vma = find_vma_prev(current->mm, start, &prev);
+	vma = find_vma_prev(mm, start, &prev);
 	error = -ENOMEM;
 	if (!vma)
 		goto out;
@@ -277,6 +278,11 @@
 		}
 	}
 out:
-	up_write(&current->mm->mmap_sem);
+	up_write(&mm->mmap_sem);
 	return error;
 }
+
+asmlinkage long sys_mprotect(unsigned long start, size_t len, unsigned long prot)
+{
+        return(do_mprotect(current->mm, start, len, prot));
+}
--- ./mm/proc_mm.c.skas	2004-06-17 16:24:30.000000000 +0200
+++ ./mm/proc_mm.c	2004-06-17 16:24:30.000000000 +0200
@@ -0,0 +1,174 @@
+/* 
+ * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
+ * Licensed under the GPL
+ */
+
+#include "linux/mm.h"
+#include "linux/init.h"
+#include "linux/proc_fs.h"
+#include "linux/proc_mm.h"
+#include "linux/file.h"
+#include "asm/uaccess.h"
+#include "asm/mmu_context.h"
+
+static struct file_operations proc_mm_fops;
+
+struct mm_struct *proc_mm_get_mm(int fd)
+{
+	struct mm_struct *ret = ERR_PTR(-EBADF);
+	struct file *file;
+
+	file = fget(fd);
+	if (!file)
+		goto out;
+
+	ret = ERR_PTR(-EINVAL);
+	if(file->f_op != &proc_mm_fops)
+		goto out_fput;
+
+	ret = file->private_data;
+ out_fput:
+	fput(file);
+ out:
+	return(ret);
+}
+
+extern long do_mmap2(struct mm_struct *mm, unsigned long addr, 
+		     unsigned long len, unsigned long prot, 
+		     unsigned long flags, unsigned long fd,
+		     unsigned long pgoff);
+
+static ssize_t write_proc_mm(struct file *file, const char *buffer,
+			     size_t count, loff_t *ppos)
+{
+	struct mm_struct *mm = file->private_data;
+	struct proc_mm_op req;
+	int n, ret;
+
+	if(count > sizeof(req))
+		return(-EINVAL);
+
+	n = copy_from_user(&req, buffer, count);
+	if(n != 0)
+		return(-EFAULT);
+
+	ret = count;
+	switch(req.op){
+	case MM_MMAP: {
+		struct mm_mmap *map = &req.u.mmap;
+
+		ret = do_mmap2(mm, map->addr, map->len, map->prot, 
+			       map->flags, map->fd, map->offset >> PAGE_SHIFT);
+		if((ret & ~PAGE_MASK) == 0)
+			ret = count;
+	
+		break;
+	}
+	case MM_MUNMAP: {
+		struct mm_munmap *unmap = &req.u.munmap;
+
+		down_write(&mm->mmap_sem);
+		ret = do_munmap(mm, unmap->addr, unmap->len);
+		up_write(&mm->mmap_sem);
+
+		if(ret == 0)
+			ret = count;
+		break;
+	}
+	case MM_MPROTECT: {
+		struct mm_mprotect *protect = &req.u.mprotect;
+
+		ret = do_mprotect(mm, protect->addr, protect->len, 
+				  protect->prot);
+		if(ret == 0)
+			ret = count;
+		break;
+	}
+
+	case MM_COPY_SEGMENTS: {
+		struct mm_struct *from = proc_mm_get_mm(req.u.copy_segments);
+
+		if(IS_ERR(from)){
+			ret = PTR_ERR(from);
+			break;
+		}
+
+		__init_new_context(mm, from);
+		break;
+	}
+	default:
+		ret = -EINVAL;
+		break;
+	}
+
+	return(ret);
+}
+
+static int open_proc_mm(struct inode *inode, struct file *file)
+{
+	struct mm_struct *mm = mm_alloc();
+	int ret;
+
+	ret = -ENOMEM;
+	if(mm == NULL)
+		goto out_mem;
+
+	ret = init_new_context(current, mm);
+	if(ret)
+		goto out_free;
+
+	spin_lock(&mmlist_lock);
+	list_add(&mm->mmlist, &current->mm->mmlist);
+	mmlist_nr++;
+	spin_unlock(&mmlist_lock);
+
+	file->private_data = mm;
+
+	return(0);
+
+ out_free:
+	mmput(mm);
+ out_mem:
+	return(ret);
+}
+
+static int release_proc_mm(struct inode *inode, struct file *file)
+{
+	struct mm_struct *mm = file->private_data;
+
+	mmput(mm);
+	return(0);
+}
+
+static struct file_operations proc_mm_fops = {
+	.open		= open_proc_mm,
+	.release	= release_proc_mm,
+	.write		= write_proc_mm,
+};
+
+static int make_proc_mm(void)
+{
+	struct proc_dir_entry *ent;
+
+	ent = create_proc_entry("mm", 0222, &proc_root);
+	if(ent == NULL){
+		printk("make_proc_mm : Failed to register /proc/mm\n");
+		return(0);
+	}
+	ent->proc_fops = &proc_mm_fops;
+
+	return(0);
+}
+
+__initcall(make_proc_mm);
+
+/*
+ * 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:
+ */
--- ./mm/Makefile.skas	2004-06-16 22:27:15.000000000 +0200
+++ ./mm/Makefile	2004-06-17 16:24:30.000000000 +0200
@@ -15,3 +15,4 @@
 obj-$(CONFIG_SWAP)	+= page_io.o swap_state.o swapfile.o
 obj-$(CONFIG_HUGETLBFS)	+= hugetlb.o
 obj-$(CONFIG_NUMA) 	+= mempolicy.o
+obj-$(CONFIG_PROC_MM)	+= proc_mm.o