commit 42d38127d243b099e984beceb5361120ab6e2655
author Nick Kralevich <nnk@google.com> Mon May 10 10:28:56 2010 -0700
committer Android (Google) Code Review <android-gerrit@google.com> Mon May 10 10:28:56 2010 -0700
tree d0d167e932fc3bf30c624b148968d58a5fb31d03
parent b20e98511dc5715f9f80e64d52fa0feb825a2e27
parent beeeee705bcf16d705748713ea40dca3486cc7b7

Merge "Allow pixelflinger to work when NX (No Execute) is enabled." into kraken

libpixelflinger/codeflinger/CodeCache.cpp

diff --git a/libpixelflinger/codeflinger/CodeCache.cpp b/libpixelflinger/codeflinger/CodeCache.cpp
index 29410c8..5877ff4 100644
--- a/libpixelflinger/codeflinger/CodeCache.cpp
+++ b/libpixelflinger/codeflinger/CodeCache.cpp
@@ -19,6 +19,8 @@
 #include <assert.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <unistd.h>
+#include <sys/mman.h>
 
 #include <cutils/log.h>
 #include <cutils/atomic.h>
@@ -39,15 +41,14 @@
 Assembly::Assembly(size_t size)
     : mCount(1), mSize(0)
 {
-    mBase = (uint32_t*)malloc(size);
-    if (mBase) {
-        mSize = size;
-    }
+    mBase = (uint32_t*)mspace_malloc(getMspace(), size);
+    mSize = size;
+    ensureMbaseExecutable();
 }
 
 Assembly::~Assembly()
 {
-    free(mBase);
+    mspace_free(getMspace(), mBase);
 }
 
 void Assembly::incStrong(const void*) const
@@ -75,11 +76,32 @@
 
 ssize_t Assembly::resize(size_t newSize)
 {
-    mBase = (uint32_t*)realloc(mBase, newSize);
+    mBase = (uint32_t*)mspace_realloc(getMspace(), mBase, newSize);
     mSize = newSize;
+    ensureMbaseExecutable();
     return size();
 }
 
+mspace Assembly::getMspace()
+{
+    static mspace msp = create_contiguous_mspace(2 * 1024, 1024 * 1024, /*locked=*/ false);
+    return msp;
+}
+
+void Assembly::ensureMbaseExecutable()
+{
+    long pagesize = sysconf(_SC_PAGESIZE);
+    long pagemask = ~(pagesize - 1);  // assumes pagesize is a power of 2
+
+    uint32_t* pageStart = (uint32_t*) (((uintptr_t) mBase) & pagemask);
+    size_t adjustedLength = mBase - pageStart + mSize;
+
+    if (mBase && mprotect(pageStart, adjustedLength, PROT_READ | PROT_WRITE | PROT_EXEC) != 0) {
+        mspace_free(getMspace(), mBase);
+        mBase = NULL;
+    }
+}
+
 // ----------------------------------------------------------------------------
 
 CodeCache::CodeCache(size_t size)

libpixelflinger/codeflinger/CodeCache.h

diff --git a/libpixelflinger/codeflinger/CodeCache.h b/libpixelflinger/codeflinger/CodeCache.h
index 8ff1366..aaafd26 100644
--- a/libpixelflinger/codeflinger/CodeCache.h
+++ b/libpixelflinger/codeflinger/CodeCache.h
@@ -22,6 +22,7 @@
 #include <stdint.h>
 #include <pthread.h>
 #include <sys/types.h>
+#include <cutils/mspace.h>
 
 #include "tinyutils/KeyedVector.h"
 #include "tinyutils/smartpointer.h"
@@ -67,9 +68,12 @@
     typedef void    weakref_type;
 
 private:
+    static  mspace  getMspace();
+            void    ensureMbaseExecutable();
+
     mutable int32_t     mCount;
             uint32_t*   mBase;
-            ssize_t     mSize;
+            size_t      mSize;
 };
 
 // ----------------------------------------------------------------------------