vbox的更動 46570 路徑 trunk/src/VBox/Runtime/r3/posix

時間撮記:

2013-6-14 下午04:47:24 (11 年 以前)

作者:

vboxsync

訊息:

hacked up a way of getting one block of low memory.

檔案:

• trunk/src/VBox/Runtime/r3/posix/allocex-r3-posix.cpp (複製) (複製 從 trunk/src/VBox/Runtime/r3/generic/allocex-r3-generic.cpp ) (7 筆差異)

trunk/src/VBox/Runtime/r3/posix/allocex-r3-posix.cpp

@@ -1 +1 @@
 /* $Id$ */
 /** @file
- * IPRT - Memory Allocation, Extended Alloc and Free Functions for Ring-3, generic.
+ * IPRT - Memory Allocation, Extended Alloc and Free Functions for Ring-3, posix.
  */
 
@@ -37 +37 @@
 #include "internal/magics.h"
 
+#include <sys/mman.h>
+
 
 /*******************************************************************************
@@ -59 +61 @@
 
 
+/**
+ * Allocates memory with upper boundrary.
+ *
+ * @returns Pointer to mmap allocation.
+ * @param   cbAlloc             Number of bytes to alloacate.
+ * @param   fFlags              Allocation flags.
+ */
+static void *rtMemAllocExAllocLow(size_t cbAlloc, uint32_t fFlags)
+{
+    int       fProt     = PROT_READ | PROT_WRITE | (fFlags & RTMEMALLOCEX_FLAGS_EXEC ? PROT_EXEC : 0);
+    uintptr_t uAddrLast = fFlags & RTMEMALLOCEX_FLAGS_16BIT_REACH ? _1M - 1 : UINT32_MAX;
+    uintptr_t uAddr     = fFlags & RTMEMALLOCEX_FLAGS_16BIT_REACH ? 0x1000  : _1M;
+    void *pv = mmap((void *)uAddr, cbAlloc, fProt, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+    if (pv && ((uintptr_t)(pv) + cbAlloc - 1U) > uAddrLast)
+    {
+        munmap(pv, cbAlloc);
+        return NULL;
+    }
+    /** @todo On linux, this method works for exactly one allocation. need to do
+     *        OS specific stuff to select a good address hint. Leaving this as a
+     *        TODO for now as I only need one allocation. */
+    return pv;
+}
+
 
 RTDECL(int) RTMemAllocExTag(size_t cb, size_t cbAlignment, uint32_t fFlags, const char *pszTag, void **ppv) RT_NO_THROW
@@ -70 +96 @@
     AssertMsgReturn(cbAlignment <= sizeof(void *), ("%zu (%#x)\n", cbAlignment, cbAlignment), VERR_UNSUPPORTED_ALIGNMENT);
 
-    if (fFlags & (RTMEMALLOCEX_FLAGS_16BIT_REACH | RTMEMALLOCEX_FLAGS_32BIT_REACH | RTMEMALLOCEX_FLAGS_ANY_CTX))
+    if (fFlags & RTMEMALLOCEX_FLAGS_ANY_CTX)
         return VERR_NOT_SUPPORTED;
 
@@ -81 +107 @@
     else
         cbAligned = RT_ALIGN_Z(cb, sizeof(uint64_t));
-    AssertMsgReturn(cbAligned >= cb && cbAligned <= ~(size_t)0 / 2U, ("cbAligned=%#zx cb=%#zx", cbAligned, cb),
+    AssertMsgReturn(cbAligned >= cb && cbAligned <= ~(size_t)0, ("cbAligned=%#zx cb=%#zx", cbAligned, cb),
                     VERR_INVALID_PARAMETER);
 
@@ -88 +114 @@
      */
     void *pv;
-    if (fFlags & RTMEMALLOCEX_FLAGS_EXEC)
+    if (fFlags & (RTMEMALLOCEX_FLAGS_16BIT_REACH | RTMEMALLOCEX_FLAGS_32BIT_REACH))
+        pv = rtMemAllocExAllocLow(cbAligned + sizeof(RTMEMHDRR3), fFlags);
+    else if (fFlags & RTMEMALLOCEX_FLAGS_EXEC)
     {
         pv = RTMemExecAlloc(cbAligned + sizeof(RTMEMHDRR3));
@@ -127 +155 @@
     Assert(pHdr->cbReq == cb);
 
-    if (pHdr->fFlags & RTMEMALLOCEX_FLAGS_EXEC)
+    if (pHdr->fFlags & (RTMEMALLOCEX_FLAGS_16BIT_REACH | RTMEMALLOCEX_FLAGS_32BIT_REACH))
+        munmap(pHdr, pHdr->cb + sizeof(*pHdr));
+    else if (pHdr->fFlags & RTMEMALLOCEX_FLAGS_EXEC)
         RTMemExecFree(pHdr, pHdr->cb + sizeof(*pHdr));
     else