Fix pthread tls bug.

Signed-off-by: Zhang Lili <lili.z.zhang@intel.com>

Author: lzha101

sdk/pthread/pthread.cpp

@@ -89,7 +89,10 @@ __thread pthread_info pthread_info_tls = {NULL, NULL, {0, 0, 0, 0, 0, 0, 0, 0},
 
 bool _pthread_enabled(void)
 {
-    pthread_info_tls.m_local_storage = NULL;
+    if(is_tcs_binding_mode() == false)
+    {
+        pthread_info_tls.m_local_storage = NULL;
+    }
     pthread_info_tls.m_pthread = NULL;
     pthread_info_tls.m_state = SGX_SUCCESS;
     memset((char*)&pthread_info_tls.m_mark, 0x00, sizeof(jmp_buf));

sdk/pthread/pthread_tls.cpp

@@ -25,6 +25,7 @@
 #include "internal/arch.h"
 #include "internal/thread_data.h"
 #include "trts_internal.h"
+#include "trts_util.h"
 
 #define PTHREAD_DESTRUCTOR_ITERATIONS		4
 #define PTHREAD_KEYS_MAX			256
@@ -173,7 +174,13 @@ void _pthread_tls_destructors(void)
     struct sgx_pthread_storage *rs;
     int i;
 
-    if(NULL == pthread_info_tls.m_pthread)
+    // For a child thread created inside enclave, we need to clear the TLS when
+    // the thread exits.
+    // In other cases, we need to make decision based on the tcs policy:
+    //   1) Unbinding mode, we need to clear the TLS before the root ecall exits.
+    //   2) Binding mode, we need to persist the TLS across multiple ECALLs. In this
+    //      case, the destructor should not be called.
+    if(NULL == pthread_info_tls.m_pthread && true == is_tcs_binding_mode())
         //do nothing
         return;
 

sdk/trts/trts_util.cpp

@@ -213,3 +213,8 @@ bool is_pkru_enabled()
         return true;
     return false;
 }
+
+bool is_tcs_binding_mode()
+{
+    return g_global_data.thread_policy == 0 ? true : false;
+}

sdk/trts/trts_util.h

@@ -60,6 +60,8 @@ bool is_utility_thread();
 size_t get_max_tcs_num();
 bool is_pkru_enabled();
 
+bool is_tcs_binding_mode();
+
 #ifdef __cplusplus
 }
 #endif