Deal with non-executable memory on Darwin (only an issue on Darwin/x86 so far)

[ghc-hetmet.git] / ghc / rts / RtsUtils.c

diff --git a/ghc/rts/RtsUtils.c b/ghc/rts/RtsUtils.c
index 646fba9..3e7e225 100644 (file)
--- a/ghc/rts/RtsUtils.c
+++ b/ghc/rts/RtsUtils.c
@@ -40,6 +40,24 @@
 #include <pthread.h>
 #endif
 
+#if defined(openbsd_HOST_OS) || defined(linux_HOST_OS) || defined(darwin_HOST_OS)
+#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
+#endif
+
+#if defined(_WIN32)
+#include <windows.h>
+#endif
+
 /* -----------------------------------------------------------------------------
    Result-checking malloc wrappers.
    -------------------------------------------------------------------------- */
@@ -73,11 +91,14 @@ stgReallocBytes (void *p, int n, char *msg)
 void *
 stgCallocBytes (int n, int m, char *msg)
 {
-  int   i;
-  int   sz = n * m;
-  char* p  = stgMallocBytes(sz, msg);
-  for (i = 0; i < sz; i++) p[i] = 0;
-  return p;
+    char *space;
+
+    if ((space = (char *) calloc((size_t) n, (size_t) m)) == NULL) {
+      /* don't fflush(stdout); WORKAROUND bug in Linux glibc */
+      MallocFailHook((W_) n*m, msg); /*msg*/
+      stg_exit(EXIT_INTERNAL_ERROR);
+    }
+    return space;
 }
 
 /* To simplify changing the underlying allocator used
@@ -168,9 +189,13 @@ time_str(void)
 
     if (now == 0) {
        time(&now);
+#if HAVE_CTIME_R
+       ctime_r(&now, nowstr);
+#else
        strcpy(nowstr, ctime(&now));
-       strcpy(nowstr+16,nowstr+19);
-       nowstr[21] = '\0';
+#endif
+       memmove(nowstr+16,nowstr+19,7);
+       nowstr[21] = '\0';  // removes the \n
     }
     return nowstr;
 }
@@ -301,3 +326,42 @@ int genericRaise(int sig) {
         return raise(sig);
 #endif
 }
+
+/* -----------------------------------------------------------------------------
+   Allocating executable memory
+   -------------------------------------------------------------------------- */
+
+/* Heavily arch-specific, I'm afraid.. */
+
+/*
+ * Allocate len bytes which are readable, writable, and executable.
+ *
+ * ToDo: If this turns out to be a performance bottleneck, one could
+ * e.g. cache the last VirtualProtect/mprotect-ed region and do
+ * nothing in case of a cache hit.
+ */
+void*
+stgMallocBytesRWX(int len)
+{
+  void *addr = stgMallocBytes(len, "mallocBytesRWX");
+#if defined(i386_HOST_ARCH) && defined(_WIN32)
+  /* This could be necessary for processors which distinguish between READ and
+     EXECUTE memory accesses, e.g. Itaniums. */
+  DWORD dwOldProtect = 0;
+  if (VirtualProtect (addr, len, PAGE_EXECUTE_READWRITE, &dwOldProtect) == 0) {
+    barf("mallocBytesRWX: failed to protect 0x%p; error=%lu; old protection: %lu\n",
+         addr, (unsigned long)GetLastError(), (unsigned long)dwOldProtect);
+  }
+#elif defined(openbsd_HOST_OS) || defined(linux_HOST_OS) || defined(darwin_HOST_OS)
+  /* malloced memory isn't executable by default on OpenBSD */
+  my_uintptr_t pageSize         = sysconf(_SC_PAGESIZE);
+  my_uintptr_t mask             = ~(pageSize - 1);
+  my_uintptr_t startOfFirstPage = ((my_uintptr_t)addr          ) & mask;
+  my_uintptr_t startOfLastPage  = ((my_uintptr_t)addr + len - 1) & mask;
+  my_uintptr_t size             = startOfLastPage - startOfFirstPage + pageSize;
+  if (mprotect((void*)startOfFirstPage, (size_t)size, PROT_EXEC | PROT_READ | PROT_WRITE) != 0) {
+    barf("mallocBytesRWX: failed to protect 0x%p\n", addr);
+  }
+#endif
+  return addr;
+}