Consolidate pthread_atfork

The pthread_atfork is similar between Linux and Hurd, only the compat
version bits differs.  The generic version is place at sysdeps/pthread
with a common name.

It also fixes an issue with Hurd license, where the static-only object
did not use LGPL + exception.

Checked on x86_64-linux-gnu, i686-linux-gnu, and with a build for
i686-gnu.

htl/Makefile

@@ -121,7 +121,6 @@ libpthread-routines := pt-attr pt-attr-destroy pt-attr-getdetachstate	    \
 	pt-sigstate-destroy						    \
 	pt-sigstate							    \
 									    \
-	old_pt-atfork							    \
 	pt-kill								    \
 	pt-getcpuclockid						    \
 									    \
@@ -165,9 +164,8 @@ headers :=				\
 
 distribute :=
 
-routines := forward libc_pthread_init alloca_cutoff pt-atfork htlfreeres
+routines := forward libc_pthread_init alloca_cutoff htlfreeres
 shared-only-routines = forward
-static-only-routines = pt-atfork
 
 extra-libs := libpthread
 extra-libs-others := $(extra-libs)

nptl/Makefile

@@ -52,7 +52,6 @@ routines = \
   nptl_nthreads \
   nptl_setxid \
   nptlfreeres \
-  old_pthread_atfork \
   old_pthread_cond_broadcast \
   old_pthread_cond_destroy \
   old_pthread_cond_init \

sysdeps/htl/old_pt-atfork.c

@@ -1,26 +0,0 @@
-/* Register fork handlers.  Generic version.
-   Copyright (C) 2002-2021 Free Software Foundation, Inc.
-   This file is part of the GNU C Library.
-
-   The GNU C Library is free software; you can redistribute it and/or
-   modify it under the terms of the GNU Lesser General Public
-   License as published by the Free Software Foundation; either
-   version 2.1 of the License, or (at your option) any later version.
-
-   The GNU C Library is distributed in the hope that it will be useful,
-   but WITHOUT ANY WARRANTY; without even the implied warranty of
-   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-   Lesser General Public License for more details.
-
-   You should have received a copy of the GNU Lesser General Public
-   License along with the GNU C Library;  if not, see
-   <https://www.gnu.org/licenses/>.  */
-
-#include <shlib-compat.h>
-
-#if SHLIB_COMPAT(libpthread, GLIBC_2_12, GLIBC_2_23)
-# define __pthread_atfork __dyn_pthread_atfork
-# include "pt-atfork.c"
-# undef __pthread_atfork
-compat_symbol (libpthread, __dyn_pthread_atfork, pthread_atfork, GLIBC_2_12);
-#endif

sysdeps/htl/pt-atfork.c

@@ -1,41 +0,0 @@
-/* Register fork handlers.  Generic version.
-   Copyright (C) 2002-2021 Free Software Foundation, Inc.
-   This file is part of the GNU C Library.
-
-   The GNU C Library is free software; you can redistribute it and/or
-   modify it under the terms of the GNU Lesser General Public
-   License as published by the Free Software Foundation; either
-   version 2.1 of the License, or (at your option) any later version.
-
-   The GNU C Library is distributed in the hope that it will be useful,
-   but WITHOUT ANY WARRANTY; without even the implied warranty of
-   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-   Lesser General Public License for more details.
-
-   You should have received a copy of the GNU Lesser General Public
-   License along with the GNU C Library;  if not, see
-   <https://www.gnu.org/licenses/>.  */
-
-#include <pthread.h>
-#include <pt-internal.h>
-#include <dso_handle.h>
-#include <register-atfork.h>
-
-/* Hide the symbol so that no definition but the one locally in the
-   executable or DSO is used.  */
-int
-#ifndef __pthread_atfork
-/* Don't mark the compatibility function as hidden.  */
-attribute_hidden
-#endif
-__pthread_atfork (void (*prepare) (void),
-		void (*parent) (void),
-		void (*child) (void))
-{
-  return __register_atfork (prepare, parent, child, __dso_handle);
-}
-#ifndef __pthread_atfork
-extern int pthread_atfork (void (*prepare) (void), void (*parent) (void),
-                           void (*child) (void)) attribute_hidden;
-weak_alias (__pthread_atfork, pthread_atfork)
-#endif

sysdeps/htl/pthread_atfork_compat.h

@@ -0,0 +1,4 @@
+/* The compat version for the dynamic pthread_atfork provided by libpthread,
+   before supported __dso_handle was added.  */
+#define PTHREAD_ATFORK_COMPAT_INTRODUCED  GLIBC_2_12
+#define PTHREAD_ATFORK_COMPAT_OBSOLETED   GLIBC_2_23

sysdeps/nptl/pthread_atfork_compat.h

@@ -0,0 +1,4 @@
+/* The compat versions for the dynamic pthread_atfork provided by libpthread,
+   before supported __dso_handle was added.  */
+#define PTHREAD_ATFORK_COMPAT_INTRODUCED  GLIBC_2_0
+#define PTHREAD_ATFORK_COMPAT_OBSOLETED   GLIBC_2_3

sysdeps/pthread/Makefile

@@ -29,7 +29,7 @@ endif
 ifneq (,$(filter $(subdir),htl nptl))
 headers += threads.h
 
-routines += thrd_current thrd_equal thrd_sleep thrd_yield
+routines += thrd_current thrd_equal thrd_sleep thrd_yield pthread_atfork
 
 $(libpthread-routines-var) += \
   call_once \
@@ -45,6 +45,7 @@ $(libpthread-routines-var) += \
   mtx_timedlock \
   mtx_trylock \
   mtx_unlock \
+  pthread_atfork_compat \
   thrd_create \
   thrd_detach \
   thrd_exit \
@@ -134,6 +135,7 @@ tests-time64 := \
   tst-sem5-time64 \
   tst-thrd-sleep-time64 \
 
+static-only-routines = pthread_atfork
 
 # Files which must not be linked with libpthread.
 tests-nolibpthread += tst-unload

sysdeps/pthread/pthread_atfork.c

@@ -36,6 +36,7 @@
 #include "pthreadP.h"
 #include <register-atfork.h>
 #include <dso_handle.h>
+#include <register-atfork.h>
 
 
 /* Hide the symbol so that no definition but the one locally in the

sysdeps/pthread/pthread_atfork_compat.c

@@ -1,6 +1,6 @@
-/* Copyright (C) 2002-2021 Free Software Foundation, Inc.
+/* Compat pthread_atfork implementation.
+   Copyright (C) 2002-2021 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
-   Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
 
    The GNU C Library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
@@ -16,11 +16,13 @@
    License along with the GNU C Library; if not, see
    <https://www.gnu.org/licenses/>.  */
 
+#include <pthread_atfork_compat.h>
 #include <shlib-compat.h>
 
 #if OTHER_SHLIB_COMPAT (libpthread, GLIBC_2_0, GLIBC_2_3)
 # define __pthread_atfork __dyn_pthread_atfork
 # include "pthread_atfork.c"
 # undef __pthread_atfork
-compat_symbol (libpthread, __dyn_pthread_atfork, pthread_atfork, GLIBC_2_0);
+compat_symbol (libpthread, __dyn_pthread_atfork, pthread_atfork,
+	       PTHREAD_ATFORK_COMPAT_INTRODUCED);
 #endif