Revert of Non-SFI mode: Add Linux asynchronous signal support

src/nonsfi/irt/irt_interfaces.c

Index: src/nonsfi/irt/irt_interfaces.c
diff --git a/src/nonsfi/irt/irt_interfaces.c b/src/nonsfi/irt/irt_interfaces.c
index 6294cda080fff86dac79d2ac58f7378f3a91540a..f0e0c01c0a312330a4b37aa46c18401b97af339f 100644
--- a/src/nonsfi/irt/irt_interfaces.c
+++ b/src/nonsfi/irt/irt_interfaces.c
@@ -28,6 +28,7 @@
 #include "native_client/src/include/nacl/nacl_exception.h"
 #include "native_client/src/include/nacl_macros.h"
 #include "native_client/src/public/irt_core.h"
+#include "native_client/src/public/nonsfi/irt_exception_handling.h"
 #include "native_client/src/trusted/service_runtime/include/machine/_types.h"
 #include "native_client/src/trusted/service_runtime/include/sys/mman.h"
 #include "native_client/src/trusted/service_runtime/include/sys/stat.h"
@@ -43,7 +44,6 @@
 #endif
 
 #if defined(__native_client__)
-# include "native_client/src/nonsfi/linux/irt_signal_handling.h"
 # include "native_client/src/nonsfi/linux/linux_pthread_private.h"
 #endif
 
@@ -366,9 +366,9 @@
   abort();
 }
 
+static int thread_create(void (*start_func)(void), void *stack,
+                         void *thread_ptr) {
 #if defined(__native_client__)
-static int thread_create_nonsfi(void (*start_func)(void), void *stack,
-                                void *thread_ptr, nacl_irt_tid_t *child_tid) {
   struct thread_args *args = malloc(sizeof(struct thread_args));
   if (args == NULL) {
     return ENOMEM;
@@ -376,25 +376,10 @@
   args->start_func = start_func;
   args->thread_ptr = thread_ptr;
   /* In Linux, it is possible to use the provided stack directly. */
-  int error = nacl_user_thread_create(start_thread, stack, args, child_tid);
+  int error = nacl_user_thread_create(start_thread, stack, args);
   if (error != 0)
     free(args);
   return error;
-}
-
-static void thread_exit_nonsfi(int32_t *stack_flag) {
-  nacl_user_thread_exit(stack_flag);
-}
-#endif
-
-static int thread_create(void (*start_func)(void), void *stack,
-                         void *thread_ptr) {
-#if defined(__native_client__)
-  /*
-   * When available, use the nonsfi version that does allow the |stack| to be
-   * set in the new thread.
-   */
-  return thread_create_nonsfi(start_func, stack, thread_ptr, NULL);
 #else
   /*
    * For now, we ignore the stack that user code provides and just use
@@ -426,11 +411,7 @@
 
 static void thread_exit(int32_t *stack_flag) {
 #if defined(__native_client__)
-  /*
-   * Since we used the nonsfi version of thread_create, we must also call the
-   * nonsfi version of thread_exit to correctly clean it up.
-   */
-  thread_exit_nonsfi(stack_flag);
+  nacl_user_thread_exit(stack_flag);
 #else
   *stack_flag = 0;  /* Indicate that the user code's stack can be freed. */
   pthread_exit(NULL);
@@ -681,14 +662,6 @@
   thread_nice,
 };
 
-#if defined(__native_client__)
-const struct nacl_irt_thread_v0_2 nacl_irt_thread_v0_2 = {
-  thread_create_nonsfi,
-  thread_exit_nonsfi,
-  thread_nice,
-};
-#endif
-
 #if defined(__linux__)
 const struct nacl_irt_futex nacl_irt_futex = {
   futex_wait_abs,
@@ -748,11 +721,6 @@
   nacl_exception_set_stack,
   nacl_exception_clear_flag,
 };
-
-const struct nacl_irt_async_signal_handling nacl_irt_async_signal_handling = {
-  nacl_async_signal_set_handler,
-  nacl_async_signal_send_async_signal,
-};
 #endif
 
 #if defined(__native_client__) && defined(__arm__)
@@ -779,10 +747,6 @@
   { NACL_IRT_MEMORY_v0_3, &nacl_irt_memory, sizeof(nacl_irt_memory), NULL },
   { NACL_IRT_TLS_v0_1, &nacl_irt_tls, sizeof(nacl_irt_tls), NULL },
   { NACL_IRT_THREAD_v0_1, &nacl_irt_thread, sizeof(nacl_irt_thread), NULL },
-#if defined(__native_client__)
-  { NACL_IRT_THREAD_v0_2, &nacl_irt_thread_v0_2,
-    sizeof(nacl_irt_thread_v0_2), NULL },
-#endif
   { NACL_IRT_FUTEX_v0_1, &nacl_irt_futex, sizeof(nacl_irt_futex), NULL },
   { NACL_IRT_RANDOM_v0_1, &nacl_irt_random, sizeof(nacl_irt_random), NULL },
 #if defined(__linux__) || defined(__native_client__)
@@ -795,8 +759,6 @@
 #if defined(__native_client__)
   { NACL_IRT_EXCEPTION_HANDLING_v0_1, &nacl_irt_exception_handling,
     sizeof(nacl_irt_exception_handling), NULL },
-  { NACL_IRT_ASYNC_SIGNAL_HANDLING_v0_1, &nacl_irt_async_signal_handling,
-    sizeof(nacl_irt_async_signal_handling), NULL },
 #endif
 #if defined(__native_client__) && defined(__arm__)
   { NACL_IRT_ICACHE_v0_1, &nacl_irt_icache, sizeof(nacl_irt_icache), NULL },