OnDemand paging for heap

arch/x86/exception.c

@@ -4,7 +4,10 @@
 #include "interrupt.h"
 #include "irq.h"
 #include "klibc.h"
+#include "process.h"
 #include "thread.h"
+#include "types.h"
+#include "uaddrspace.h"
 #include "vga.h"
 
 exception_handler exception_handler_array[EXCEPTION_NUM] = {
@@ -53,8 +56,15 @@ void pagefault_handler(struct cpu_state *frame, ulong intr)
 {
 
     struct thread *current = getCurrentThread();
-    printf("page fault while in thread %s code at 0x%x when trying to access 0x%x err_code 0x%x\n", current->name,
-           cpu_context_get_PC(frame), cpu_context_get_EX_faulting_vaddr(frame), cpu_context_get_EX_err(frame));
+    struct uAddrSpace *as = processGetAddrSpace(current->process);
+    vaddr_t faultAddr = cpu_context_get_EX_faulting_vaddr(frame);
+
+    if(!uAddrSpaceCheckNAlloc(as, faultAddr))
+        return;
+
+
+    printf("page fault while in thread [%s] at 0x%x when trying to access 0x%x err_code 0x%x\n", current->name,
+           cpu_context_get_PC(frame), faultAddr, cpu_context_get_EX_err(frame));
     if (cpu_context_is_in_user_mode(frame)) {
         printf("Killing User Thread\n");
         threadExit();

core/uaddrspace.c

@@ -1,6 +1,7 @@
 #include "uaddrspace.h"
 #include "alloc.h"
 #include "kernel.h"
+#include "klibc.h"
 #include "mem.h"
 #include "mmuContext.h"
 #include "process.h"
@@ -105,15 +106,26 @@ uaddr_t sysBrk(struct uAddrSpace *as, uaddr_t newHeapTop)
         return as->heapStart + as->heapSize;
     }
 
-    //WIP do it manually
-    for (uaddr_t begin = ALIGN(as->heapStart + as->heapSize, PAGE_SIZE); begin < newHeapTop; begin += PAGE_SIZE) {
-        paddr_t ppage = allocPhyPage(1);
-        if (0 != pageMap(begin, ppage,
-                         PAGING_MEM_USER | PAGING_MEM_WRITE | PAGING_MEM_READ))
-            return (uaddr_t)NULL;
+    as->heapSize += incSize;
 
-        unrefPhyPage(ppage);
+    return 0;
+}
+
+int uAddrSpaceCheckNAlloc(struct uAddrSpace *as, vaddr_t addr)
+{
+    pr_devel("Checking %p inside %p and %p", addr, as->heapStart, as->heapStart +as->heapSize);
+    if (addr < as->heapStart || addr >= as->heapStart + as->heapSize) {
+        return -1;
     }
 
+    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;
+    }
+
+    unrefPhyPage(ppage);
+
     return 0;
 }

core/uaddrspace.h

@@ -11,4 +11,5 @@ struct uAddrSpace * uAddrSpaceCreate(struct process *proc);
 int uAddrSpaceDelete(struct uAddrSpace *addr);
 struct mmu_context * uAddrSpaceGetMMUContext(struct uAddrSpace *addr);
 int uAddrSpaceSetHeap(struct uAddrSpace *as, uaddr_t addr, size_t size);
+int uAddrSpaceCheckNAlloc(struct uAddrSpace *as, vaddr_t addr);
 uaddr_t sysBrk(struct uAddrSpace *as, uaddr_t newHeapTop);