make libacc run with execute stack protections enabled.

libacc was allocating memory using malloc for executable pages.
When running on a system where the stack and heap are not
executable, using malloc for executable pages will result in
a segfault.

This change modifies libacc to allow the code to run, even
if the system is running with executable stack and heap disabled.

Change-Id: Ia74e3d83750c09b7eefd865ff059db920093040d

1 files changed, 4 insertions, 5 deletions

diff --git a/libacc/acc.cpp b/libacc/acc.cpp
index 8f33b0b..73d2cdd 100644
--- a/libacc/acc.cpp
+++ b/libacc/acc.cpp
@@ -23,10 +23,7 @@
 
 #include <cutils/hashmap.h>
 
-#if defined(__i386__)
 #include <sys/mman.h>
-#endif
-
 
 #if defined(__arm__)
 #define DEFAULT_ARM_CODEGEN
@@ -230,7 +227,7 @@ class Compiler : public ErrorSink {
 
         void release() {
             if (pProgramBase != 0) {
-                free(pProgramBase);
+                munmap(pProgramBase, mSize);
                 pProgramBase = 0;
             }
         }
@@ -263,7 +260,9 @@ class Compiler : public ErrorSink {
         virtual void init(int size) {
             release();
             mSize = size;
-            pProgramBase = (char*) calloc(1, size);
+            pProgramBase = (char*) mmap(NULL, size, 
+                PROT_EXEC | PROT_READ | PROT_WRITE, 
+                MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
             ind = pProgramBase;
         }