OFFSET(HOST_TASK_PID, task_struct, pid);
 
 DEFINE(UM_KERN_PAGE_SIZE, PAGE_SIZE);
+DEFINE(UM_KERN_PAGE_MASK, PAGE_MASK);
 DEFINE(UM_NSEC_PER_SEC, NSEC_PER_SEC);
 
 DEFINE_STR(UM_KERN_EMERG, KERN_EMERG);
 
 #include "uml-config.h"
 #include "os.h"
 #include "um_malloc.h"
+#include "kern_constants.h"
 
 /* Set in main, unchanged thereafter */
 char *linux_prog;
 
        if(!CAN_KMALLOC())
                return __real_malloc(size);
-       else if(size <= PAGE_SIZE) /* finding contiguos pages can be hard*/
+       else if(size <= UM_KERN_PAGE_SIZE)
+               /* finding contiguous pages can be hard*/
                ret = um_kmalloc(size);
        else ret = um_vmalloc(size);
 
 
 #include "sysdep/ptrace.h"
 #include "sysdep/stub.h"
 #include "init.h"
+#include "kern_constants.h"
 
 extern unsigned long batch_syscall_stub, __syscall_stub_start;
 
        *stack = 0;
        multi_op_count++;
 
-       if(!done && ((((unsigned long) stack) & ~PAGE_MASK) <
-                    PAGE_SIZE - 10 * sizeof(long))){
+       if(!done && ((((unsigned long) stack) & ~UM_KERN_PAGE_MASK) <
+                    UM_KERN_PAGE_SIZE - 10 * sizeof(long))){
                *addr = stack;
                return 0;
        }
        /* If *addr still is uninitialized, it *must* contain NULL.
         * Thus in this case do_syscall_stub correctly won't be called.
         */
-       if((((unsigned long) *addr) & ~PAGE_MASK) >=
-          PAGE_SIZE - (10 + data_count) * sizeof(long)) {
+       if((((unsigned long) *addr) & ~UM_KERN_PAGE_MASK) >=
+          UM_KERN_PAGE_SIZE - (10 + data_count) * sizeof(long)) {
                ret = do_syscall_stub(mm_idp, addr);
                /* in case of error, don't overwrite data on stack */
                if(ret)
 
        memcpy(stack + 1, data, data_count * sizeof(long));
 
-       *stub_addr = (void *)(((unsigned long)(stack + 1) & ~PAGE_MASK) +
-                             UML_CONFIG_STUB_DATA);
+       *stub_addr = (void *)(((unsigned long)(stack + 1) &
+                              ~UM_KERN_PAGE_MASK) + UML_CONFIG_STUB_DATA);
 
        return 0;
 }
 
        unsigned long sp;
        int pid, status, n, flags;
 
-       stack = mmap(NULL, PAGE_SIZE, PROT_READ | PROT_WRITE | PROT_EXEC,
+       stack = mmap(NULL, UM_KERN_PAGE_SIZE,
+                    PROT_READ | PROT_WRITE | PROT_EXEC,
                     MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
        if(stack == MAP_FAILED)
                panic("start_userspace : mmap failed, errno = %d", errno);
-       sp = (unsigned long) stack + PAGE_SIZE - sizeof(void *);
+       sp = (unsigned long) stack + UM_KERN_PAGE_SIZE - sizeof(void *);
 
        flags = CLONE_FILES | SIGCHLD;
        if(proc_mm) flags |= CLONE_VM;
                panic("start_userspace : PTRACE_OLDSETOPTIONS failed, errno=%d\n",
                      errno);
 
-       if(munmap(stack, PAGE_SIZE) < 0)
+       if(munmap(stack, UM_KERN_PAGE_SIZE) < 0)
                panic("start_userspace : munmap failed, errno = %d\n", errno);
 
        return(pid);
        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 -
+       thread_regs[REGS_SP_INDEX] = UML_CONFIG_STUB_DATA + UM_KERN_PAGE_SIZE -
                sizeof(void *);
 #ifdef __SIGNAL_FRAMESIZE
        thread_regs[REGS_SP_INDEX] -= __SIGNAL_FRAMESIZE;
                                      .u         =
                                      { .mmap    =
                                        { .addr    = code,
-                                         .len     = PAGE_SIZE,
+                                         .len     = UM_KERN_PAGE_SIZE,
                                          .prot    = PROT_EXEC,
                                          .flags   = MAP_FIXED | MAP_PRIVATE,
                                          .fd      = code_fd,
                                  .u         =
                                  { .mmap    =
                                    { .addr    = data,
-                                     .len     = PAGE_SIZE,
+                                     .len     = UM_KERN_PAGE_SIZE,
                                      .prot    = PROT_READ | PROT_WRITE,
                                      .flags   = MAP_FIXED | MAP_SHARED,
                                      .fd      = map_fd,
 
        unsigned long sp;
        int pid, n, status;
 
-       stack = mmap(NULL, PAGE_SIZE, PROT_READ | PROT_WRITE | PROT_EXEC,
+       stack = mmap(NULL, UM_KERN_PAGE_SIZE,
+                    PROT_READ | PROT_WRITE | PROT_EXEC,
                     MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
        if(stack == MAP_FAILED)
                fatal_perror("check_ptrace : mmap failed");
-       sp = (unsigned long) stack + PAGE_SIZE - sizeof(void *);
+       sp = (unsigned long) stack + UM_KERN_PAGE_SIZE - sizeof(void *);
        pid = clone(ptrace_child, (void *) sp, SIGCHLD, NULL);
        if(pid < 0)
                fatal_perror("start_ptraced_child : clone failed");
                ret = -1;
        }
 
-       if(munmap(stack, PAGE_SIZE) < 0)
+       if(munmap(stack, UM_KERN_PAGE_SIZE) < 0)
                fatal_perror("check_ptrace : munmap failed");
        return ret;
 }