[patch] libffi part of the fix (3.0.10)

libffi-3.0.10-honor-PROT_EXEC-restrictions.patch (text/plain), 1.34 KB, created by Pavel Labushev on 2011-12-28 10:37:18 UTC

--- a/src/closures.c
+++ b/src/closures.c
@@ -458,29 +458,19 @@ dlmmap (void *start, size_t length, int
   printf ("mapping in %zi\n", length);
 #endif
 
-  if (execfd == -1 && !is_selinux_enabled ())
+  ptr = mmap (start, length, prot | PROT_EXEC, flags, fd, offset);
+  if (ptr != MFAIL || (errno != EPERM && errno != EACCES))
     {
-      ptr = mmap (start, length, prot | PROT_EXEC, flags, fd, offset);
-
-      if (ptr != MFAIL || (errno != EPERM && errno != EACCES))
-	/* Cool, no need to mess with separate segments.  */
-	return ptr;
-
-      /* If MREMAP_DUP is ever introduced and implemented, try mmap
-	 with ((prot & ~PROT_WRITE) | PROT_EXEC) and mremap with
-	 MREMAP_DUP and prot at this point.  */
+      return ptr;
     }
-
-  if (execsize == 0 || execfd == -1)
+  else
     {
-      pthread_mutex_lock (&open_temp_exec_file_mutex);
-      ptr = dlmmap_locked (start, length, prot, flags, offset);
-      pthread_mutex_unlock (&open_temp_exec_file_mutex);
-
-      return ptr;
+      /* Retry without PROT_EXEC. This should work in most cases. */
+      ptr = mmap (start, length, prot, flags, fd, offset);
+      if (ptr != MFAIL || (errno != EPERM && errno != EACCES))
+        return ptr;
     }
-
-  return dlmmap_locked (start, length, prot, flags, offset);
+  return MFAIL;
 }
 
 /* Release memory at the given address, as well as the corresponding