nptl: Perform signal initialization upon pthread_create

Install signal handlers and unblock signals before pthread_create
creates the first thread.

create_thread in sysdeps/unix/sysv/linux/createthread.c can send
SIGCANCEL to the current thread, so the SIGCANCEL handler is currently
needed even if pthread_cancel is never called.  (The way timer_create
uses SIGCANCEL does not need a signal handler; both SIG_DFL and SIG_IGN
dispositions should work.)

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>

1 files changed, 3 insertions, 2 deletions

diff --git a/nptl/Versions b/nptl/Versions
index e7883cbb49..d96b830d05 100644
--- a/nptl/Versions
+++ b/nptl/Versions
@@ -367,8 +367,6 @@ libc {
     tss_set;
   }
   GLIBC_PRIVATE {
-     __nptl_create_event;
-     __nptl_death_event;
     __default_pthread_attr;
     __default_pthread_attr_lock;
     __futex_abstimed_wait64;
@@ -386,11 +384,14 @@ libc {
     __lll_trylock_elision;
     __lll_unlock_elision;
     __mutex_aconf;
+    __nptl_create_event;
     __nptl_deallocate_stack;
     __nptl_deallocate_tsd;
+    __nptl_death_event;
     __nptl_free_tcb;
     __nptl_nthreads;
     __nptl_setxid_sighandler;
+    __nptl_sigcancel_handler;
     __nptl_stack_list_add;
     __nptl_stack_list_del;
     __pthread_attr_copy;