From: Klaus Treichel <ktreichel@web.de>
Date: Tue, 22 Aug 2006 18:02:55 +0000 (+0000)
Subject: 2006-08-22  Klaus treichel  <ktreichel@web.de>
X-Git-Tag: before.move.to.git~209
X-Git-Url: https://git.unchartedbackwaters.co.uk/w/?a=commitdiff_plain;h=f9dc32bbdc16546cdd56ded8145b8bc40eb47e61;p=francis%2Flibjit.git

2006-08-22  Klaus treichel  <ktreichel@web.de>

	* jit/jit-alloc.c: Use mmap and munmap to allocate executable memory
	where available because memory allocated with malloc is not executable
	on some archs/distros.
---

diff --git a/ChangeLog b/ChangeLog
index a50d4d5..44d417f 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2006-08-22  Klaus treichel  <ktreichel@web.de>
+
+	* jit/jit-alloc.c: Use mmap and munmap to allocate executable memory
+	where available because memory allocated with malloc is not executable
+	on some archs/distros.
+
 2006-08-23  Aleksey Demakov  <ademakov@gmail.com>
 
 	* jit/jit-reg-alloc.c: improve handling of three-address op codes.
diff --git a/jit/jit-alloc.c b/jit/jit-alloc.c
index cd3ea47..e279382 100644
--- a/jit/jit-alloc.c
+++ b/jit/jit-alloc.c
@@ -40,6 +40,21 @@
 	#include <windows.h>
 	#include <io.h>
 #endif
+#if defined(HAVE_SYS_MMAN_H) && defined(HAVE_MMAP) && defined(HAVE_MUNMAP)
+/*
+ * Make sure that "MAP_ANONYMOUS" is correctly defined, because it
+ * may not exist on some variants of Unix.
+ */
+#ifndef MAP_ANONYMOUS
+    #ifdef MAP_ANON
+        #define MAP_ANONYMOUS        MAP_ANON
+    #endif
+#endif
+#ifdef MAP_ANONYMOUS
+#define JIT_USE_MMAP
+#endif
+#endif
+
 
 /*@
  * @section Memory allocation
@@ -126,7 +141,18 @@ void jit_free(void *ptr)
 @*/
 void *jit_malloc_exec(unsigned int size)
 {
+#ifdef JIT_USE_MMAP
+	void *ptr = mmap(0, size, PROT_READ | PROT_WRITE | PROT_EXEC,
+							  MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+
+	if(ptr == (void *)-1)
+	{
+		return (void *)0;
+	}
+	return ptr;
+#else
 	return malloc(size);
+#endif
 }
 
 /*@
@@ -141,7 +167,11 @@ void jit_free_exec(void *ptr, unsigned int size)
 {
 	if(ptr)
 	{
+	#ifdef JIT_USE_MMAP
+		munmap(ptr, size);
+	#else
 		free(ptr);
+	#endif
 	}
 }