diff --git a/core/stdarg.h b/core/stdarg.h
index a045ddd..7c40c3c 100644
--- a/core/stdarg.h
+++ b/core/stdarg.h
@@ -42,10 +42,12 @@ typedef enum { FALSE = 0, TRUE } bool_t;
 typedef unsigned long size_t;
 typedef long ssize_t;
 typedef unsigned long int uintptr_t;
+typedef long int intptr_t;
 #else
 typedef unsigned int size_t;
 typedef int ssize_t;
 typedef unsigned int uintptr_t;
+typedef int intptr_t;
 #endif
 
 //__builtin_va_list could be used instead
diff --git a/core/uaddrspace.c b/core/uaddrspace.c
index 4dd74d2..efd224c 100644
--- a/core/uaddrspace.c
+++ b/core/uaddrspace.c
@@ -2,6 +2,7 @@
 #include "alloc.h"
 #include "kernel.h"
 #include "klibc.h"
+#include "list.h"
 #include "mem.h"
 #include "mmuContext.h"
 #include "process.h"
@@ -50,7 +51,7 @@ struct mappedRessource {
 
 struct uAddrSpace *uAddrSpaceCreate(struct process *proc)
 {
-    struct uAddrSpace *addr = (struct uAddrSpace *)malloc(sizeof(struct uAddrSpace));
+    struct uAddrSpace *addr = (struct uAddrSpace *)zalloc(sizeof(struct uAddrSpace));
 
     if (addr == NULL)
         return NULL;
@@ -64,13 +65,23 @@ struct uAddrSpace *uAddrSpaceCreate(struct process *proc)
     }
 
     addr->process = proc;
+    list_init(addr->listVirtualReg);
 
     return addr;
 }
 
 int uAddrSpaceDelete(struct uAddrSpace *addr)
 {
-    // TODO Work on Virtual Region
+    struct uAddrVirtualReg *reg;
+
+    list_collapse_named(addr->listVirtualReg, reg, nextInAddrSpace, prevInAddrSpace) {
+        // TODO Implement me with real ressources
+        assertmsg(reg->res == NULL, "Unsupported mapper ressource");
+        // This is memory allocated for the heap just unmap it to free it
+        pr_devel("Freeing heap for process %s\n", processGetName(addr->process));
+        pageUnmap(reg->addr);
+        free(reg);
+    }
     return mmuContextUnref(addr->ctx);
 }
 
@@ -102,30 +113,48 @@ uaddr_t sysBrk(struct uAddrSpace *as, uaddr_t newHeapTop)
     incSize = ALIGN(newHeapTop - (as->heapStart + as->heapSize), PAGE_SIZE);
 
     if (incSize < 0){
-        //FIXME
+        //TODO how to free allocated page by uAddrSpaceCheckNAlloc
         return as->heapStart + as->heapSize;
     }
 
     as->heapSize += incSize;
 
-    return 0;
+    return as->heapStart + as->heapSize;
 }
 
 int uAddrSpaceCheckNAlloc(struct uAddrSpace *as, vaddr_t addr)
 {
+    struct uAddrVirtualReg *newReg;
+    int right = PAGING_MEM_USER | PAGING_MEM_WRITE | PAGING_MEM_READ;
+
     pr_devel("Checking %lx inside %lx and %lx\n", addr, as->heapStart, as->heapStart +as->heapSize);
     if (addr < as->heapStart || addr >= as->heapStart + as->heapSize) {
         return -1;
     }
 
+    pr_devel("Alloc heap for process %s\n", processGetName(as->process));
+
     vaddr_t addrAlign = ALIGN_DOWN(addr, PAGE_SIZE);
     paddr_t ppage     = allocPhyPage(1);
 
-    if (0 != pageMap(addrAlign, ppage, PAGING_MEM_USER | PAGING_MEM_WRITE | PAGING_MEM_READ)) {
-        return -1;
-    }
+    if (0 != pageMap(addrAlign, ppage, right))
+        goto free_ppage;
+
+    newReg = zalloc(sizeof(struct uAddrVirtualReg));
+
+    if (newReg == NULL)
+        goto free_ppage;
+
+    newReg->addr = addrAlign;
+    newReg->size = PAGE_SIZE;
+    newReg->right = right;
+
+    list_add_tail_named(as->listVirtualReg, newReg, nextInAddrSpace, prevInAddrSpace);
 
     unrefPhyPage(ppage);
 
     return 0;
+free_ppage:
+    unrefPhyPage(ppage);
+    return -1;
 }
diff --git a/userspace/libc.c b/userspace/libc.c
index e39b93b..80df4e9 100644
--- a/userspace/libc.c
+++ b/userspace/libc.c
@@ -570,9 +570,26 @@ int readline(char *buf, int size)
     return i == (size-1);
 }
 
-void *brk(void *addr)
+int brk(void *addr)
 {
-    return (void *)syscall1(SYSCALL_ID_BRK, (unsigned int)addr);
+    uintptr_t new = syscall1(SYSCALL_ID_BRK, (unsigned int)addr);
+
+    //errno = ENOMEM
+    return (new >= (uintptr_t)addr)?0:-1;
+
+}
+
+void *sbrk(intptr_t increment)
+{
+    void *current = (void *)syscall1(SYSCALL_ID_BRK, 0);
+    if (increment == 0) {
+        return current;
+    }
+    if (syscall1(SYSCALL_ID_BRK, (uintptr_t)current + increment)) {
+        // errno = ENOMEM
+        return (void *)-1;
+    }
+    return current;
 }
 
 static char *heapTop   = 0;
@@ -582,9 +599,9 @@ static char *lastAlloc = 0;
 void *malloc(size_t size)
 {
     if (heapTop == 0) {
-        heapTop = heapFree = brk(0);
+        heapTop = heapFree = sbrk(0);
     } else {
-        heapTop = brk(0);
+        heapTop = sbrk(0);
     }
 
     if (heapFree + size + sizeof(size) > heapTop) {
diff --git a/userspace/libc.h b/userspace/libc.h
index 65097bb..409855c 100644
--- a/userspace/libc.h
+++ b/userspace/libc.h
@@ -46,6 +46,7 @@ int testSycall5(uint arg1, uint arg2, uint arg3, uint arg4, uint arg5);
 char readc();
 char getchar();
 int readline(char *buf, int size);
-void *brk(void *addr);
+int brk(void *addr);
+void *sbrk(intptr_t increment);
 void *malloc(size_t size);
 void free(void *ptr);
diff --git a/userspace/main_user.c b/userspace/main_user.c
index b31292f..f28e678 100644
--- a/userspace/main_user.c
+++ b/userspace/main_user.c
@@ -26,11 +26,11 @@ int func_alloc()
 {
 
         if (initialHeap == 0) {
-                initialHeap = brk(0);
+                initialHeap = sbrk(0);
         }
         printf("Testing allocation\n");
         int allocSize    = 4096 * 2;
-        char *currentHeap = brk(0);
+        char *currentHeap = sbrk(0);
         if (currentHeap - initialHeap < allocSize) {
                 brk(initialHeap + allocSize);
         }
diff --git a/userspace/stdarg.h b/userspace/stdarg.h
index 0c96fb7..5760def 100644
--- a/userspace/stdarg.h
+++ b/userspace/stdarg.h
@@ -42,10 +42,12 @@ typedef enum { FALSE = 0, TRUE } bool_t;
 typedef unsigned long size_t;
 typedef long ssize_t;
 typedef unsigned long int uintptr_t;
+typedef long int intptr_t;
 #else
 typedef unsigned int size_t;
 typedef int ssize_t;
 typedef unsigned int uintptr_t;
+typedef int intptr_t;
 #endif
 
 typedef char *va_list;