Update copyright dates with scripts/update-copyrights.

[thirdparty/glibc.git] / nptl / pthread_create.c

diff --git a/nptl/pthread_create.c b/nptl/pthread_create.c
index 992331e280cfb86c7d592ff75777b8eec2508368..2bd2b10727812f277e51fa0b681a7b802f18516f 100644 (file)
--- a/nptl/pthread_create.c
+++ b/nptl/pthread_create.c
@@ -1,4 +1,4 @@
-/* Copyright (C) 2002-2017 Free Software Foundation, Inc.
+/* Copyright (C) 2002-2019 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
    Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
 
@@ -32,6 +32,7 @@
 #include <exit-thread.h>
 #include <default-sched.h>
 #include <futex-internal.h>
+#include <tls-setup.h>
 #include "libioP.h"
 
 #include <shlib-compat.h>
@@ -427,12 +428,23 @@ START_THREAD_DEFN
      compilers without that support we do use setjmp.  */
   struct pthread_unwind_buf unwind_buf;
 
-  /* No previous handlers.  */
+  int not_first_call;
+  not_first_call = setjmp ((struct __jmp_buf_tag *) unwind_buf.cancel_jmp_buf);
+
+  /* No previous handlers.  NB: This must be done after setjmp since the
+     private space in the unwind jump buffer may overlap space used by
+     setjmp to store extra architecture-specific information which is
+     never used by the cancellation-specific __libc_unwind_longjmp.
+
+     The private space is allowed to overlap because the unwinder never
+     has to return through any of the jumped-to call frames, and thus
+     only a minimum amount of saved data need be stored, and for example,
+     need not include the process signal mask information. This is all
+     an optimization to reduce stack usage when pushing cancellation
+     handlers.  */
   unwind_buf.priv.data.prev = NULL;
   unwind_buf.priv.data.cleanup = NULL;
 
-  int not_first_call;
-  not_first_call = setjmp ((struct __jmp_buf_tag *) unwind_buf.cancel_jmp_buf);
   if (__glibc_likely (! not_first_call))
     {
       /* Store the new cleanup handler info.  */
@@ -460,7 +472,19 @@ START_THREAD_DEFN
       LIBC_PROBE (pthread_start, 3, (pthread_t) pd, pd->start_routine, pd->arg);
 
       /* Run the code the user provided.  */
-      THREAD_SETMEM (pd, result, pd->start_routine (pd->arg));
+      void *ret;
+      if (pd->c11)
+       {
+         /* The function pointer of the c11 thread start is cast to an incorrect
+            type on __pthread_create_2_1 call, however it is casted back to correct
+            one so the call behavior is well-defined (it is assumed that pointers
+            to void are able to represent all values of int.  */
+         int (*start)(void*) = (int (*) (void*)) pd->start_routine;
+         ret = (void*) (uintptr_t) start (pd->arg);
+       }
+      else
+       ret = pd->start_routine (pd->arg);
+      THREAD_SETMEM (pd, result, ret);
     }
 
   /* Call destructors for the thread_local TLS variables.  */
@@ -518,7 +542,7 @@ START_THREAD_DEFN
 
 #ifndef __ASSUME_SET_ROBUST_LIST
   /* If this thread has any robust mutexes locked, handle them now.  */
-# ifdef __PTHREAD_MUTEX_HAVE_PREV
+# if __PTHREAD_MUTEX_HAVE_PREV
   void *robust = pd->robust_head.list;
 # else
   __pthread_slist_t *robust = pd->robust_list.__next;
@@ -536,7 +560,7 @@ START_THREAD_DEFN
                                         __list.__next));
          robust = *((void **) robust);
 
-# ifdef __PTHREAD_MUTEX_HAVE_PREV
+# if __PTHREAD_MUTEX_HAVE_PREV
          this->__list.__prev = NULL;
 # endif
          this->__list.__next = NULL;
@@ -613,7 +637,8 @@ __pthread_create_2_1 (pthread_t *newthread, const pthread_attr_t *attr,
   const struct pthread_attr *iattr = (struct pthread_attr *) attr;
   struct pthread_attr default_attr;
   bool free_cpuset = false;
-  if (iattr == NULL)
+  bool c11 = (attr == ATTR_C11_THREAD);
+  if (iattr == NULL || c11)
     {
       lll_lock (__default_pthread_attr_lock, LLL_PRIVATE);
       default_attr = __default_pthread_attr;
@@ -671,6 +696,7 @@ __pthread_create_2_1 (pthread_t *newthread, const pthread_attr_t *attr,
      get the information from its thread descriptor.  */
   pd->start_routine = start_routine;
   pd->arg = arg;
+  pd->c11 = c11;
 
   /* Copy the thread attribute flags.  */
   struct pthread *self = THREAD_SELF;
@@ -701,6 +727,9 @@ __pthread_create_2_1 (pthread_t *newthread, const pthread_attr_t *attr,
   THREAD_COPY_POINTER_GUARD (pd);
 #endif
 
+  /* Setup tcbhead.  */
+  tls_setup_tcbhead (pd);
+
   /* Verify the sysinfo bits were copied in allocate_stack if needed.  */
 #ifdef NEED_DL_SYSINFO
   CHECK_THREAD_SYSINFO (pd);