Changeset 29831 in vbox for trunk/src/VBox

Timestamp:

May 26, 2010 9:13:49 PM (15 years ago)

Author:

vboxsync

Message:

alloc-r0drv-freebsd.c: Simplify the allocation of executable memory for amd64. We have to use a vm object or vm_map_remove doesn't free the allocated pages

Location:

trunk/src/VBox/Runtime/r0drv/freebsd

Files:

• alloc-r0drv-freebsd.c (modified) (3 diffs)
• the-freebsd-kernel.h (modified) (1 diff)

trunk/src/VBox/Runtime/r0drv/freebsd/alloc-r0drv-freebsd.c

@@ -62 +62 @@
     if (fFlags & RTMEMHDR_FLAG_EXEC)
     {
+# if USE_KMEM_ALLOC_PROT
+        pHdr = (PRTMEMHDR)kmem_alloc_prot(kernel_map, cb + sizeof(*pHdr),
+                                          VM_PROT_ALL, VM_PROT_ALL, KERNBASE);
+# else
+        vm_object_t pVmObject = NULL;
         vm_offset_t Addr = KERNBASE;
         cbAllocated = RT_ALIGN_Z(cb + sizeof(*pHdr), PAGE_SIZE);
 
+        pVmObject = vm_object_allocate(OBJT_DEFAULT, cbAllocated >> PAGE_SHIFT);
+        if (!pVmObject)
+            return NULL;
+
         /* Addr contains a start address vm_map_find will start searching for suitable space at. */
-        int rc = vm_map_find(kernel_map, NULL, 0, &Addr,
-                             cbAllocated,
-                             TRUE, VM_PROT_ALL, VM_PROT_ALL, 0);
+        int rc = vm_map_find(kernel_map, pVmObject, 0, &Addr,
+                             cbAllocated, TRUE, VM_PROT_ALL, VM_PROT_ALL, 0);
         if (rc == KERN_SUCCESS)
         {
-            /* Add the pages. */
-            vm_offset_t AddressDst = Addr;
-            bool fSuccess = true;
-
-            do
-            {
-                vm_page_t pPage;
-
-                pPage = vm_page_alloc(NULL, 0,
-                                      VM_ALLOC_NOBUSY | VM_ALLOC_SYSTEM |
-                                      VM_ALLOC_WIRED  | VM_ALLOC_NOOBJ);
-                if (pPage)
-                {
-                    /* Put the page into the page table now. */
-                    MY_PMAP_ENTER(kernel_map->pmap, AddressDst, pPage, VM_PROT_ALL,
-                                  TRUE);
-                }
-                else
-                {
-                    /*
-                     * Allocation failed. vm_map_remove will remove any
-                     * page already allocated.
-                     */
-                    fSuccess = false;
-                    break;
-                }
-                AddressDst += PAGE_SIZE;
-            } while(AddressDst < (Addr + cbAllocated));
-
-            if (fSuccess)
+            rc = vm_map_wire(kernel_map, Addr, Addr + cbAllocated,
+                             VM_MAP_WIRE_SYSTEM | VM_MAP_WIRE_NOHOLES);
+            if (rc == KERN_SUCCESS)
             {
                 pHdr = (PRTMEMHDR)Addr;
@@ -110 +91 @@
                 vm_map_remove(kernel_map,
                               Addr,
-                              Addr + cb);
+                              Addr + cbAllocated);
         }
+        else
+            vm_object_deallocate(pVmObject);
+# endif
     }
     else
@@ -138 +122 @@
 #ifdef RT_ARCH_AMD64
     if (pHdr->fFlags & RTMEMHDR_FLAG_EXEC)
+# if USE_KMEM_ALLOC_PROT
+        kmem_free(kernel_map, (vm_offset_t)pHdr, pHdr->cb);
+# else
         vm_map_remove(kernel_map, (vm_offset_t)pHdr, ((vm_offset_t)pHdr) + pHdr->cb);
+# endif
     else
 #endif

trunk/src/VBox/Runtime/r0drv/freebsd/the-freebsd-kernel.h

@@ -105 +105 @@
 #endif
 
+/**
+ * Check whether we can use kmem_alloc_prot.
+ */
+#if 0 /** @todo Not available yet. */
+# define USE_KMEM_ALLOC_PROT
 #endif
+
+#endif