Give base::SharedMemory::CreateAnonymous an executable flag

NaCl on Mac and Linux needs to create a shared memory object that it can
later make executable with mprotect.  Express this need in the interface it
uses.  Add a test that pages mapped from such an object can later be passed
to mprotect with PROT_EXEC.

This lays the groundwork for a later change that will sometimes use a
different method to allocate an object on Linux when it needs to be
executable.  On some Linux distributions, shm_open yields objects whose
mappings cannot be made executable.

BUG= http://code.google.com/p/chromium/issues/detail?id=103377
TEST= SharedMemory.AnonymousExecutable

R=mark@chromium.org,jam@chromium.org,amit@chromium.org,ben@chromium.org

Review URL: http://codereview.chromium.org/8585002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@112570 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 4 insertions, 1 deletions

diff --git a/chrome/browser/nacl_host/nacl_process_host.cc b/chrome/browser/nacl_host/nacl_process_host.cc
index 8bc8b99..c84f416 100644
--- a/chrome/browser/nacl_host/nacl_process_host.cc
+++ b/chrome/browser/nacl_host/nacl_process_host.cc
@@ -492,7 +492,10 @@ void NaClProcessHost::SendStart(base::PlatformFile irt_file) {
   // mappable with PROT_EXEC.  Rather than requiring an extra IPC
   // round trip out of the sandbox, we create an FD here.
   base::SharedMemory memory_buffer;
-  if (!memory_buffer.CreateAnonymous(/* size= */ 1)) {
+  base::SharedMemoryCreateOptions options;
+  options.size = 1;
+  options.executable = true;
+  if (!memory_buffer.Create(options)) {
     LOG(ERROR) << "Failed to allocate memory buffer";
     delete this;
     return;