diff --git a/arch/um/Kconfig_x86_64 b/arch/um/Kconfig_x86_64
index fd8d7e8..f162f50 100644
--- a/arch/um/Kconfig_x86_64
+++ b/arch/um/Kconfig_x86_64
@@ -6,6 +6,10 @@
 	bool
 	default y
 
+config TOP_ADDR
+ 	hex
+	default 0x80000000
+
 config 3_LEVEL_PGTABLES
        bool
        default y
diff --git a/arch/um/include/sysdep-i386/ptrace.h b/arch/um/include/sysdep-i386/ptrace.h
index 84ec7ff..6eaeb99 100644
--- a/arch/um/include/sysdep-i386/ptrace.h
+++ b/arch/um/include/sysdep-i386/ptrace.h
@@ -31,7 +31,6 @@
 #ifdef UML_CONFIG_MODE_SKAS
 
 #include "skas_ptregs.h"
-#include "sysdep/faultinfo.h"
 
 #define REGS_IP(r) ((r)[HOST_IP])
 #define REGS_SP(r) ((r)[HOST_SP])
@@ -59,6 +58,7 @@
 #define PTRACE_SYSEMU_SINGLESTEP 32
 #endif
 
+#include "sysdep/faultinfo.h"
 #include "choose-mode.h"
 
 union uml_pt_regs {
diff --git a/arch/um/include/sysdep-x86_64/checksum.h b/arch/um/include/sysdep-x86_64/checksum.h
index 572c6c1..ea97005 100644
--- a/arch/um/include/sysdep-x86_64/checksum.h
+++ b/arch/um/include/sysdep-x86_64/checksum.h
@@ -9,8 +9,6 @@
 #include "linux/in6.h"
 #include "asm/uaccess.h"
 
-extern unsigned int csum_partial_copy_from(const unsigned char *src, unsigned char *dst, int len,
-					   int sum, int *err_ptr);
 extern unsigned csum_partial(const unsigned char *buff, unsigned len,
                              unsigned sum);
 
@@ -31,10 +29,15 @@
 }
 
 static __inline__
-unsigned int csum_partial_copy_from_user(const unsigned char *src, unsigned char *dst,
-					 int len, int sum, int *err_ptr)
+unsigned int csum_partial_copy_from_user(const unsigned char *src,
+                                         unsigned char *dst, int len, int sum,
+                                         int *err_ptr)
 {
-	return csum_partial_copy_from(src, dst, len, sum, err_ptr);
+        if(copy_from_user(dst, src, len)){
+                *err_ptr = -EFAULT;
+                return(-1);
+        }
+        return csum_partial(dst, len, sum);
 }
 
 /**
@@ -137,15 +140,6 @@
         return a;
 }
 
-#endif
+extern unsigned short ip_compute_csum(unsigned char * buff, int len);
 
-/*
- * 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:
- */
+#endif
diff --git a/arch/um/include/sysdep-x86_64/ptrace.h b/arch/um/include/sysdep-x86_64/ptrace.h
index 348e8fc..be8acd5 100644
--- a/arch/um/include/sysdep-x86_64/ptrace.h
+++ b/arch/um/include/sysdep-x86_64/ptrace.h
@@ -135,6 +135,7 @@
 	__CHOOSE_MODE(SC_EFLAGS(UPT_SC(r)), REGS_EFLAGS((r)->skas.regs))
 #define UPT_SC(r) ((r)->tt.sc)
 #define UPT_SYSCALL_NR(r) __CHOOSE_MODE((r)->tt.syscall, (r)->skas.syscall)
+#define UPT_SYSCALL_RET(r) UPT_RAX(r)
 
 extern int user_context(unsigned long sp);
 
@@ -196,32 +197,32 @@
 
 
 #define UPT_SET(regs, reg, val) \
-        ({      unsigned long val; \
+        ({      unsigned long __upt_val = val; \
                 switch(reg){ \
-		case R8: UPT_R8(regs) = val; break; \
-		case R9: UPT_R9(regs) = val; break; \
-		case R10: UPT_R10(regs) = val; break; \
-		case R11: UPT_R11(regs) = val; break; \
-		case R12: UPT_R12(regs) = val; break; \
-		case R13: UPT_R13(regs) = val; break; \
-		case R14: UPT_R14(regs) = val; break; \
-		case R15: UPT_R15(regs) = val; break; \
-                case RIP: UPT_IP(regs) = val; break; \
-                case RSP: UPT_SP(regs) = val; break; \
-                case RAX: UPT_RAX(regs) = val; break; \
-                case RBX: UPT_RBX(regs) = val; break; \
-                case RCX: UPT_RCX(regs) = val; break; \
-                case RDX: UPT_RDX(regs) = val; break; \
-                case RSI: UPT_RSI(regs) = val; break; \
-                case RDI: UPT_RDI(regs) = val; break; \
-                case RBP: UPT_RBP(regs) = val; break; \
-                case ORIG_RAX: UPT_ORIG_RAX(regs) = val; break; \
-                case CS: UPT_CS(regs) = val; break; \
-                case DS: UPT_DS(regs) = val; break; \
-                case ES: UPT_ES(regs) = val; break; \
-                case FS: UPT_FS(regs) = val; break; \
-                case GS: UPT_GS(regs) = val; break; \
-                case EFLAGS: UPT_EFLAGS(regs) = val; break; \
+                case R8: UPT_R8(regs) = __upt_val; break; \
+                case R9: UPT_R9(regs) = __upt_val; break; \
+                case R10: UPT_R10(regs) = __upt_val; break; \
+                case R11: UPT_R11(regs) = __upt_val; break; \
+                case R12: UPT_R12(regs) = __upt_val; break; \
+                case R13: UPT_R13(regs) = __upt_val; break; \
+                case R14: UPT_R14(regs) = __upt_val; break; \
+                case R15: UPT_R15(regs) = __upt_val; break; \
+                case RIP: UPT_IP(regs) = __upt_val; break; \
+                case RSP: UPT_SP(regs) = __upt_val; break; \
+                case RAX: UPT_RAX(regs) = __upt_val; break; \
+                case RBX: UPT_RBX(regs) = __upt_val; break; \
+                case RCX: UPT_RCX(regs) = __upt_val; break; \
+                case RDX: UPT_RDX(regs) = __upt_val; break; \
+                case RSI: UPT_RSI(regs) = __upt_val; break; \
+                case RDI: UPT_RDI(regs) = __upt_val; break; \
+                case RBP: UPT_RBP(regs) = __upt_val; break; \
+                case ORIG_RAX: UPT_ORIG_RAX(regs) = __upt_val; break; \
+                case CS: UPT_CS(regs) = __upt_val; break; \
+                case DS: UPT_DS(regs) = __upt_val; break; \
+                case ES: UPT_ES(regs) = __upt_val; break; \
+                case FS: UPT_FS(regs) = __upt_val; break; \
+                case GS: UPT_GS(regs) = __upt_val; break; \
+                case EFLAGS: UPT_EFLAGS(regs) = __upt_val; break; \
                 default :  \
                         panic("Bad register in UPT_SET : %d\n", reg);  \
 			break; \
@@ -245,14 +246,3 @@
         CHOOSE_MODE((&(r)->tt.faultinfo), (&(r)->skas.faultinfo))
 
 #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:
- */
diff --git a/arch/um/kernel/ptrace.c b/arch/um/kernel/ptrace.c
index 2b75d8d..2925e15 100644
--- a/arch/um/kernel/ptrace.c
+++ b/arch/um/kernel/ptrace.c
@@ -28,9 +28,9 @@
         child->thread.singlestep_syscall = 0;
 
 #ifdef SUBARCH_SET_SINGLESTEPPING
-        SUBARCH_SET_SINGLESTEPPING(child, on)
+        SUBARCH_SET_SINGLESTEPPING(child, on);
 #endif
-                }
+}
 
 /*
  * Called by kernel/ptrace.c when detaching..
@@ -83,7 +83,7 @@
 	}
 
 #ifdef SUBACH_PTRACE_SPECIAL
-        SUBARCH_PTRACE_SPECIAL(child,request,addr,data)
+        SUBARCH_PTRACE_SPECIAL(child,request,addr,data);
 #endif
 
 	ret = ptrace_check_attach(child, request == PTRACE_KILL);
diff --git a/arch/um/kernel/uml.lds.S b/arch/um/kernel/uml.lds.S
index 76eadb3..dd53555 100644
--- a/arch/um/kernel/uml.lds.S
+++ b/arch/um/kernel/uml.lds.S
@@ -73,6 +73,8 @@
 
   .got           : { *(.got.plt) *(.got) }
   .dynamic       : { *(.dynamic) }
+  .tdata	  : { *(.tdata .tdata.* .gnu.linkonce.td.*) }
+  .tbss		  : { *(.tbss .tbss.* .gnu.linkonce.tb.*) *(.tcommon) }
   /* We want the small data sections together, so single-instruction offsets
      can access them all, and initialized data all before uninitialized, so
      we can shorten the on-disk segment size.  */
diff --git a/arch/um/sys-i386/Makefile b/arch/um/sys-i386/Makefile
index fcd67c3..4351e56 100644
--- a/arch/um/sys-i386/Makefile
+++ b/arch/um/sys-i386/Makefile
@@ -9,11 +9,11 @@
 
 SYMLINKS = bitops.c semaphore.c highmem.c module.c
 
+include arch/um/scripts/Makefile.rules
+
 bitops.c-dir = lib
 semaphore.c-dir = kernel
 highmem.c-dir = mm
 module.c-dir = kernel
 
 subdir- := util
-
-include arch/um/scripts/Makefile.rules
diff --git a/arch/um/sys-x86_64/Makefile b/arch/um/sys-x86_64/Makefile
index 3d7da911..608466a 100644
--- a/arch/um/sys-x86_64/Makefile
+++ b/arch/um/sys-x86_64/Makefile
@@ -14,11 +14,11 @@
 
 USER_OBJS := ptrace_user.o sigcontext.o
 
-include arch/um/scripts/Makefile.rules
-
 SYMLINKS = bitops.c csum-copy.S csum-partial.c csum-wrappers.c memcpy.S \
 	semaphore.c thunk.S module.c
 
+include arch/um/scripts/Makefile.rules
+
 bitops.c-dir = lib
 csum-copy.S-dir = lib
 csum-partial.c-dir = lib
@@ -28,6 +28,4 @@
 thunk.S-dir = lib
 module.c-dir = kernel
 
-CFLAGS_csum-partial.o := -Dcsum_partial=arch_csum_partial
-
 subdir- := util
diff --git a/arch/um/sys-x86_64/ksyms.c b/arch/um/sys-x86_64/ksyms.c
index a27f0ee..8592738 100644
--- a/arch/um/sys-x86_64/ksyms.c
+++ b/arch/um/sys-x86_64/ksyms.c
@@ -16,5 +16,4 @@
 EXPORT_SYMBOL(__memcpy);
 
 /* Networking helper routines. */
-/*EXPORT_SYMBOL(csum_partial_copy_from);
-EXPORT_SYMBOL(csum_partial_copy_to);*/
+EXPORT_SYMBOL(ip_compute_csum);
diff --git a/arch/um/sys-x86_64/ptrace.c b/arch/um/sys-x86_64/ptrace.c
index b593bb2..74eee5c 100644
--- a/arch/um/sys-x86_64/ptrace.c
+++ b/arch/um/sys-x86_64/ptrace.c
@@ -5,10 +5,11 @@
  */
 
 #define __FRAME_OFFSETS
-#include "asm/ptrace.h"
-#include "linux/sched.h"
-#include "linux/errno.h"
-#include "asm/elf.h"
+#include <asm/ptrace.h>
+#include <linux/sched.h>
+#include <linux/errno.h>
+#include <asm/uaccess.h>
+#include <asm/elf.h>
 
 /* XXX x86_64 */
 unsigned long not_ss;
diff --git a/arch/um/sys-x86_64/syscalls.c b/arch/um/sys-x86_64/syscalls.c
index dd99146..d4a5965 100644
--- a/arch/um/sys-x86_64/syscalls.c
+++ b/arch/um/sys-x86_64/syscalls.c
@@ -15,6 +15,7 @@
 #include "asm/unistd.h"
 #include "asm/prctl.h" /* XXX This should get the constants from libc */
 #include "choose-mode.h"
+#include "kern.h"
 
 asmlinkage long sys_uname64(struct new_utsname __user * name)
 {
diff --git a/arch/um/sys-x86_64/user-offsets.c b/arch/um/sys-x86_64/user-offsets.c
index 5e14792..513d17c 100644
--- a/arch/um/sys-x86_64/user-offsets.c
+++ b/arch/um/sys-x86_64/user-offsets.c
@@ -3,6 +3,14 @@
 #include <signal.h>
 #define __FRAME_OFFSETS
 #include <asm/ptrace.h>
+#include <asm/types.h>
+/* For some reason, x86_64 defines u64 and u32 only in <pci/types.h>, which I
+ * refuse to include here, even though they're used throughout the headers.
+ * These are used in asm/user.h, and that include can't be avoided because of
+ * the sizeof(struct user_regs_struct) below.
+ */
+typedef __u64 u64;
+typedef __u32 u32;
 #include <asm/user.h>
 
 #define DEFINE(sym, val) \