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 9852311f9b8989853bbea82e5df8cbc783457475..496582678625c849fb7d7a81ff758bd07414a40d 100644
--- a/src/nonsfi/irt/irt_interfaces.c
+++ b/src/nonsfi/irt/irt_interfaces.c
@@ -26,9 +26,9 @@
 #include "native_client/src/include/elf32.h"
 #include "native_client/src/include/elf_auxv.h"
 #include "native_client/src/include/nacl/nacl_exception.h"
+#include "native_client/src/include/nacl/nacl_signal.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"
@@ -45,6 +45,7 @@
 
 #if defined(__native_client__)
 # include "native_client/src/nonsfi/linux/linux_pthread_private.h"
+# include "native_client/src/public/nonsfi/irt_signal_handling.h"
 #endif
 
 /*
@@ -358,19 +359,6 @@ static void *start_thread(void *arg) {
 
 static int thread_create(void (*start_func)(void), void *stack,
                          void *thread_ptr) {
-#if defined(__native_client__)

[Mark Seaborn, 2015/07/16 23:21:16]

By removing this, you're changing NACL_IRT_THREAD_v0_1 back to ignoring the
stack provided and allocating its own.  That's a bit icky.  It would be better
if the only difference between NACL_IRT_THREAD_v0_{1,2} is whether the TID can
optionally be set.

[Luis Héctor Chávez, 2015/07/20 18:13:47]

Done.

-  struct thread_args *args = malloc(sizeof(struct thread_args));
-  if (args == NULL) {
-    return ENOMEM;
-  }
-  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);
-  if (error != 0)
-    free(args);
-  return error;
-#else
   /*
    * For now, we ignore the stack that user code provides and just use
    * the stack that the host libpthread allocates.
@@ -396,18 +384,34 @@ static int thread_create(void (*start_func)(void), void *stack,
  cleanup:
   pthread_attr_destroy(&attr);
   return error;
-#endif
 }
 
 static void thread_exit(int32_t *stack_flag) {
-#if defined(__native_client__)
-  nacl_user_thread_exit(stack_flag);
-#else
   *stack_flag = 0;  /* Indicate that the user code's stack can be freed. */
   pthread_exit(NULL);
-#endif
 }
 
+#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;
+  }
+  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);
+  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_nice(const int nice) {
   return 0;
 }
@@ -612,6 +616,14 @@ const struct nacl_irt_thread nacl_irt_thread = {
   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,
@@ -672,6 +684,11 @@ const struct nacl_irt_exception_handling nacl_irt_exception_handling = {
   nacl_exception_set_stack,
   nacl_exception_clear_flag,
 };
+
+const struct nacl_irt_async_signal_handling nacl_irt_async_signal_handling = {
+  nacl_signal_set_handler,
+  nacl_signal_send_async_signal,
+};
 #endif
 
 #if defined(__native_client__) && defined(__arm__)
@@ -696,6 +713,10 @@ static const struct nacl_irt_interface irt_interfaces[] = {
   { 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__)
@@ -708,6 +729,8 @@ static const struct nacl_irt_interface irt_interfaces[] = {
 #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 },