Pull from github (tstellar):

Prefer using memfd_create() for the ring buffer.

We were using /dev/shm, but this won't work on systems that
either don't have /dev/shm or have mounted it with noexec, because
for everything other than gfx700 we map the ring buffer with PROT_EXEC.

memfd_create() is Linux specific and was added in Linux 3.17, so we
will fallback to using /dev/shm on systems where memfd_create() is
not available.

Change-Id: I58fb533eebc362f6d29dc3e316a80801014d50e8

runtime/hsa-runtime/core/inc/amd_aql_queue.h

@@ -349,6 +349,10 @@ class AqlQueue : public core::Queue, private core::LocalSignal, public core::Sig
   void AllocRegisteredRingBuffer(uint32_t queue_size_pkts);
   void FreeRegisteredRingBuffer();
 
+  /// @brief Abstracts the file handle use for double mapping queues.
+  void CloseRingBufferFD(const char* ring_buf_shm_path, int fd) const;
+  int CreateRingBufferFD(const char* ring_buf_shm_path, uint32_t ring_buf_phys_size_bytes) const;
+
   static bool DynamicScratchHandler(hsa_signal_value_t error_code, void* arg);
 
   /// @brief Define the Scratch Buffer Descriptor and related parameters