1 files changed, 145 insertions, 0 deletions
diff --git a/src/mapi/u_execmem.c b/src/mapi/u_execmem.c
new file mode 100644
index 00000000000..e5072e06e9a
--- /dev/null
+++ b/src/mapi/u_execmem.c
@@ -0,0 +1,145 @@
+/*
+ * Mesa 3-D graphics library
+ * Version:  6.5
+ *
+ * Copyright (C) 1999-2005  Brian Paul   All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+ * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+
+/**
+ * \file glapi_execmem.c
+ *
+ * Function for allocating executable memory for dispatch stubs.
+ *
+ * Copied from main/execmem.c and simplified for dispatch stubs.
+ */
+
+
+#include "u_compiler.h"
+#include "u_thread.h"
+#include "u_execmem.h"
+
+
+#define EXEC_MAP_SIZE (4*1024)
+
+u_mutex_declare_static(exec_mutex);
+
+static unsigned int head = 0;
+
+static unsigned char *exec_mem = (unsigned char *)0;
+
+
+#if defined(__linux__) || defined(__OpenBSD__) || defined(_NetBSD__) || defined(__sun)
+
+#include <unistd.h>
+#include <sys/mman.h>
+
+#ifdef MESA_SELINUX
+#include <selinux/selinux.h>
+#endif
+
+
+#ifndef MAP_ANONYMOUS
+#define MAP_ANONYMOUS MAP_ANON
+#endif
+
+
+/*
+ * Dispatch stubs are of fixed size and never freed. Thus, we do not need to
+ * overlay a heap, we just mmap a page and manage through an index.
+ */
+
+static int
+init_map(void)
+{
+#ifdef MESA_SELINUX
+   if (is_selinux_enabled()) {
+      if (!security_get_boolean_active("allow_execmem") ||
+	  !security_get_boolean_pending("allow_execmem"))
+         return 0;
+   }
+#endif
+
+   if (!exec_mem)
+      exec_mem = mmap(NULL, EXEC_MAP_SIZE, PROT_EXEC | PROT_READ | PROT_WRITE,
+		      MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+
+   return (exec_mem != MAP_FAILED);
+}
+
+
+#elif defined(_WIN32)
+
+#include <windows.h>
+
+
+/*
+ * Avoid Data Execution Prevention.
+ */
+
+static int
+init_map(void)
+{
+   exec_mem = VirtualAlloc(NULL, EXEC_MAP_SIZE, MEM_COMMIT, PAGE_EXECUTE_READWRITE);
+
+   return (exec_mem != NULL);
+}
+
+
+#else
+
+#include <stdlib.h>
+
+static int
+init_map(void)
+{
+   exec_mem = malloc(EXEC_MAP_SIZE);
+
+   return (exec_mem != NULL);
+}
+
+
+#endif
+
+void *
+u_execmem_alloc(unsigned int size)
+{
+   void *addr = NULL;
+
+   u_mutex_lock(exec_mutex);
+
+   if (!init_map())
+      goto bail;
+
+   /* free space check, assumes no integer overflow */
+   if (head + size > EXEC_MAP_SIZE)
+      goto bail;
+
+   /* allocation, assumes proper addr and size alignement */
+   addr = exec_mem + head;
+   head += size;
+
+bail:
+   u_mutex_unlock(exec_mutex);
+
+   return addr;
+}
+
+