replace stgMallocBytesRWX() with our own allocator

[ghc-hetmet.git] / rts / posix / OSMem.c

diff --git a/rts/posix/OSMem.c b/rts/posix/OSMem.c
new file mode 100644 (file)
index 0000000..6e8337b
--- /dev/null
+++ b/rts/posix/OSMem.c
@@ -0,0 +1,52 @@
+/* -----------------------------------------------------------------------------
+ *
+ * (c) The University of Glasgow 2006
+ *
+ * OS-specific memory management
+ *
+ * ---------------------------------------------------------------------------*/
+
+#include "Rts.h"
+#include "OSMem.h"
+
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/mman.h>
+
+/* no C99 header stdint.h on OpenBSD? */
+#if defined(openbsd_HOST_OS)
+typedef unsigned long my_uintptr_t;
+#else
+#include <stdint.h>
+typedef uintptr_t my_uintptr_t;
+#endif
+
+lnat getPageSize (void)
+{
+    static lnat pageSize = 0;
+    if (pageSize) {
+       return pageSize;
+    } else {
+       long ret;
+       ret = sysconf(_SC_PAGESIZE);
+       if (ret == -1) {
+           barf("getPageSize: cannot get page size");
+       }
+       return ret;
+    }
+}
+
+void setExecutable (void *p, lnat len, rtsBool exec)
+{
+    my_uintptr_t pageSize = getPageSize();
+
+    /* malloced memory isn't executable by default on OpenBSD */
+    my_uintptr_t mask             = ~(pageSize - 1);
+    my_uintptr_t startOfFirstPage = ((my_uintptr_t)p          ) & mask;
+    my_uintptr_t startOfLastPage  = ((my_uintptr_t)p + len - 1) & mask;
+    my_uintptr_t size             = startOfLastPage - startOfFirstPage + pageSize;
+    if (mprotect((void*)startOfFirstPage, (size_t)size, 
+                (exec ? PROT_EXEC : 0) | PROT_READ | PROT_WRITE) != 0) {
+       barf("makeExecutable: failed to protect 0x%p\n", p);
+    }
+}