Refactor internal-signals.h

The main drive is to optimize the internal usage and required size
when sigset_t is embedded in other data structures.  On Linux, the
current supported signal set requires up to 8 bytes (16 on mips),
was lower than the user defined sigset_t (128 bytes).

A new internal type internal_sigset_t is added, along with the
functions to operate on it similar to the ones for sigset_t.  The
internal-signals.h is also refactored to remove unused functions

Besides small stack usage on some functions (posix_spawn, abort)
it lower the struct pthread by about 120 bytes (112 on mips).

Checked on x86_64-linux-gnu.

Reviewed-by: Arjun Shankar <arjun@redhat.com>

5 files changed, 17 insertions, 16 deletions

diff --git a/nptl/descr.h b/nptl/descr.h
index b585263..5cacb28 100644
--- a/nptl/descr.h
+++ b/nptl/descr.h
@@ -35,6 +35,7 @@
 #include <kernel-features.h>
 #include <tls-internal-struct.h>
 #include <sys/rseq.h>
+#include <internal-sigset.h>
 
 #ifndef TCB_ALIGNMENT
 # define TCB_ALIGNMENT 32
@@ -387,7 +388,7 @@ struct pthread
   /* Signal mask for the new thread.  Used during thread startup to
      restore the signal mask.  (Threads are launched with all signals
      masked.)  */
-  sigset_t sigmask;
+  internal_sigset_t sigmask;
 
   /* Indicates whether is a C11 thread created by thrd_creat.  */
   bool c11;
diff --git a/nptl/pthread_attr_setsigmask.c b/nptl/pthread_attr_setsigmask.c
index a6e650f..908a0c1 100644
--- a/nptl/pthread_attr_setsigmask.c
+++ b/nptl/pthread_attr_setsigmask.c
@@ -28,7 +28,7 @@ pthread_attr_setsigmask_np (pthread_attr_t *attr, const sigset_t *sigmask)
 
   /* Filter out internal signals.  */
   struct pthread_attr *iattr = (struct pthread_attr *) attr;
-  __clear_internal_signals (&iattr->extension->sigmask);
+  clear_internal_signals (&iattr->extension->sigmask);
 
   return 0;
 }
diff --git a/nptl/pthread_create.c b/nptl/pthread_create.c
index a06d611..308db65 100644
--- a/nptl/pthread_create.c
+++ b/nptl/pthread_create.c
@@ -423,7 +423,7 @@ start_thread (void *arg)
       /* Store the new cleanup handler info.  */
       THREAD_SETMEM (pd, cleanup_jmp_buf, &unwind_buf);
 
-      __libc_signal_restore_set (&pd->sigmask);
+      internal_signal_restore_set (&pd->sigmask);
 
       LIBC_PROBE (pthread_start, 3, (pthread_t) pd, pd->start_routine, pd->arg);
 
@@ -501,8 +501,8 @@ start_thread (void *arg)
      signal to be delivered.  (SIGSETXID cannot run application code,
      nor does it use pthread_kill.)  Reuse the pd->sigmask space for
      computing the signal mask, to save stack space.  */
-  __sigfillset (&pd->sigmask);
-  __sigdelset (&pd->sigmask, SIGSETXID);
+  internal_sigfillset (&pd->sigmask);
+  internal_sigdelset (&pd->sigmask, SIGSETXID);
   INTERNAL_SYSCALL_CALL (rt_sigprocmask, SIG_BLOCK, &pd->sigmask, NULL,
 			 __NSIG_BYTES);
 
@@ -769,14 +769,14 @@ __pthread_create_2_1 (pthread_t *newthread, const pthread_attr_t *attr,
   /* Block all signals, so that the new thread starts out with
      signals disabled.  This avoids race conditions in the thread
      startup.  */
-  sigset_t original_sigmask;
-  __libc_signal_block_all (&original_sigmask);
+  internal_sigset_t original_sigmask;
+  internal_signal_block_all (&original_sigmask);
 
   if (iattr->extension != NULL && iattr->extension->sigmask_set)
     /* Use the signal mask in the attribute.  The internal signals
        have already been filtered by the public
        pthread_attr_setsigmask_np interface.  */
-    pd->sigmask = iattr->extension->sigmask;
+    internal_sigset_from_sigset (&pd->sigmask, &iattr->extension->sigmask);
   else
     {
       /* Conceptually, the new thread needs to inherit the signal mask
@@ -786,7 +786,7 @@ __pthread_create_2_1 (pthread_t *newthread, const pthread_attr_t *attr,
       pd->sigmask = original_sigmask;
       /* Reset the cancellation signal mask in case this thread is
 	 running cancellation.  */
-      __sigdelset (&pd->sigmask, SIGCANCEL);
+      internal_sigdelset (&pd->sigmask, SIGCANCEL);
     }
 
   /* Start the thread.  */
@@ -833,7 +833,7 @@ __pthread_create_2_1 (pthread_t *newthread, const pthread_attr_t *attr,
 
   /* Return to the previous signal mask, after creating the new
      thread.  */
-  __libc_signal_restore_set (&original_sigmask);
+  internal_signal_restore_set (&original_sigmask);
 
   if (__glibc_unlikely (retval != 0))
     {
diff --git a/nptl/pthread_kill.c b/nptl/pthread_kill.c
index 8015e10..178d38d 100644
--- a/nptl/pthread_kill.c
+++ b/nptl/pthread_kill.c
@@ -45,8 +45,8 @@ __pthread_kill_implementation (pthread_t threadid, int signo, int no_tid)
     }
 
   /* Block all signals, as required by pd->exit_lock.  */
-  sigset_t old_mask;
-  __libc_signal_block_all (&old_mask);
+  internal_sigset_t old_mask;
+  internal_signal_block_all (&old_mask);
   __libc_lock_lock (pd->exit_lock);
 
   int ret;
@@ -64,7 +64,7 @@ __pthread_kill_implementation (pthread_t threadid, int signo, int no_tid)
     }
 
   __libc_lock_unlock (pd->exit_lock);
-  __libc_signal_restore_set (&old_mask);
+  internal_signal_restore_set (&old_mask);
 
   return ret;
 }
@@ -83,7 +83,7 @@ __pthread_kill (pthread_t threadid, int signo)
 {
   /* Disallow sending the signal we use for cancellation, timers,
      for the setxid implementation.  */
-  if (__is_internal_signal (signo))
+  if (is_internal_signal (signo))
     return EINVAL;
 
   return __pthread_kill_internal (threadid, signo);
@@ -102,7 +102,7 @@ int
 attribute_compat_text_section
 __pthread_kill_esrch (pthread_t threadid, int signo)
 {
-  if (__is_internal_signal (signo))
+  if (is_internal_signal (signo))
     return EINVAL;
 
   return __pthread_kill_implementation (threadid, signo, ESRCH);
diff --git a/nptl/pthread_sigmask.c b/nptl/pthread_sigmask.c
index 20f811c..977740b 100644
--- a/nptl/pthread_sigmask.c
+++ b/nptl/pthread_sigmask.c
@@ -32,7 +32,7 @@ __pthread_sigmask (int how, const sigset_t *newmask, sigset_t *oldmask)
          || __glibc_unlikely (__sigismember (newmask, SIGSETXID))))
     {
       local_newmask = *newmask;
-      __clear_internal_signals (&local_newmask);
+      clear_internal_signals (&local_newmask);
       newmask = &local_newmask;
     }