nptl: Consolidate async cancel enable/disable implementation in libc

Previously, the source file nptl/cancellation.c was compiled multiple
times, for libc, libpthread, librt.  This commit switches to a single
implementation, with new __pthread_enable_asynccancel@@GLIBC_PRIVATE,
__pthread_disable_asynccancel@@GLIBC_PRIVATE exports.

The almost-unused CANCEL_ASYNC and CANCEL_RESET macros are replaced
by LIBC_CANCEL_ASYNC and LIBC_CANCEL_ASYNC macros.  They call the
__pthread_* functions unconditionally now.  The macros are still
needed because shared code uses them; Hurd has different definitions.

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

5 files changed, 12 insertions, 72 deletions

diff --git a/sysdeps/nptl/Makefile b/sysdeps/nptl/Makefile
index adcced422b..632cd3686b 100644
--- a/sysdeps/nptl/Makefile
+++ b/sysdeps/nptl/Makefile
@@ -21,8 +21,7 @@ libpthread-sysdep_routines += errno-loc
 endif
 
 ifeq ($(subdir),rt)
-librt-sysdep_routines += timer_routines librt-cancellation
-CFLAGS-librt-cancellation.c += -fexceptions -fasynchronous-unwind-tables
+librt-sysdep_routines += timer_routines
 
 tests += tst-mqueue8x
 CFLAGS-tst-mqueue8x.c += -fexceptions
diff --git a/sysdeps/nptl/librt-cancellation.c b/sysdeps/nptl/librt-cancellation.c
deleted file mode 100644
index 1ad0eb11ff..0000000000
--- a/sysdeps/nptl/librt-cancellation.c
+++ /dev/null
@@ -1,24 +0,0 @@
-/* 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
-   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 <nptl/pthreadP.h>
-
-
-#define __pthread_enable_asynccancel __librt_enable_asynccancel
-#define __pthread_disable_asynccancel __librt_disable_asynccancel
-#include <nptl/cancellation.c>
diff --git a/sysdeps/nptl/lowlevellock-futex.h b/sysdeps/nptl/lowlevellock-futex.h
index ca96397a4a..66ebfe50f4 100644
--- a/sysdeps/nptl/lowlevellock-futex.h
+++ b/sysdeps/nptl/lowlevellock-futex.h
@@ -121,18 +121,18 @@
 /* Like lll_futex_wait, but acting as a cancellable entrypoint.  */
 # define lll_futex_wait_cancel(futexp, val, private) \
   ({                                                                   \
-    int __oldtype = CANCEL_ASYNC ();				       \
+    int __oldtype = LIBC_CANCEL_ASYNC ();			       \
     long int __err = lll_futex_wait (futexp, val, LLL_SHARED);	       \
-    CANCEL_RESET (__oldtype);					       \
+    LIBC_CANCEL_RESET (__oldtype);				       \
     __err;							       \
   })
 
 /* Like lll_futex_timed_wait, but acting as a cancellable entrypoint.  */
 # define lll_futex_timed_wait_cancel(futexp, val, timeout, private) \
   ({									   \
-    int __oldtype = CANCEL_ASYNC ();				       	   \
+    int __oldtype = LIBC_CANCEL_ASYNC ();			       	   \
     long int __err = lll_futex_timed_wait (futexp, val, timeout, private); \
-    CANCEL_RESET (__oldtype);						   \
+    LIBC_CANCEL_RESET (__oldtype);					   \
     __err;								   \
   })
 
diff --git a/sysdeps/unix/sysv/linux/socketcall.h b/sysdeps/unix/sysv/linux/socketcall.h
index 07702fc4f1..3084623216 100644
--- a/sysdeps/unix/sysv/linux/socketcall.h
+++ b/sysdeps/unix/sysv/linux/socketcall.h
@@ -89,11 +89,6 @@
   })
 
 
-#if IS_IN (libc)
-# define __pthread_enable_asynccancel  __libc_enable_asynccancel
-# define __pthread_disable_asynccancel __libc_disable_asynccancel
-#endif
-
 #define SOCKETCALL_CANCEL(name, args...)				\
   ({									\
     int oldtype = LIBC_CANCEL_ASYNC ();					\
diff --git a/sysdeps/unix/sysv/linux/sysdep-cancel.h b/sysdeps/unix/sysv/linux/sysdep-cancel.h
index da2f08fde9..c64cfff37c 100644
--- a/sysdeps/unix/sysv/linux/sysdep-cancel.h
+++ b/sysdeps/unix/sysv/linux/sysdep-cancel.h
@@ -24,44 +24,14 @@
 #include <tls.h>
 #include <errno.h>
 
-/* The two functions are in libc.so and not exported.  */
-extern int __libc_enable_asynccancel (void) attribute_hidden;
-extern void __libc_disable_asynccancel (int oldtype) attribute_hidden;
-
-/* The two functions are in librt.so and not exported.  */
-extern int __librt_enable_asynccancel (void) attribute_hidden;
-extern void __librt_disable_asynccancel (int oldtype) attribute_hidden;
-
-/* The two functions are in libpthread.so and not exported.  */
-extern int __pthread_enable_asynccancel (void) attribute_hidden;
-extern void __pthread_disable_asynccancel (int oldtype) attribute_hidden;
-
 /* Set cancellation mode to asynchronous.  */
-#define CANCEL_ASYNC() \
-  __pthread_enable_asynccancel ()
-/* Reset to previous cancellation mode.  */
-#define CANCEL_RESET(oldtype) \
-  __pthread_disable_asynccancel (oldtype)
-
-#if IS_IN (libc)
-/* Same as CANCEL_ASYNC, but for use in libc.so.  */
-# define LIBC_CANCEL_ASYNC() \
-  __libc_enable_asynccancel ()
-/* Same as CANCEL_RESET, but for use in libc.so.  */
-# define LIBC_CANCEL_RESET(oldtype) \
-  __libc_disable_asynccancel (oldtype)
-#elif IS_IN (libpthread)
-# define LIBC_CANCEL_ASYNC() CANCEL_ASYNC ()
-# define LIBC_CANCEL_RESET(val) CANCEL_RESET (val)
-#elif IS_IN (librt)
-# define LIBC_CANCEL_ASYNC() \
-  __librt_enable_asynccancel ()
-# define LIBC_CANCEL_RESET(val) \
-  __librt_disable_asynccancel (val)
-#else
-# define LIBC_CANCEL_ASYNC()	0 /* Just a dummy value.  */
-# define LIBC_CANCEL_RESET(val)	((void)(val)) /* Nothing, but evaluate it.  */
-#endif
+extern int __pthread_enable_asynccancel (void);
+libc_hidden_proto (__pthread_enable_asynccancel)
+#define LIBC_CANCEL_ASYNC() __pthread_enable_asynccancel ()
 
+/* Reset to previous cancellation mode.  */
+extern void __pthread_disable_asynccancel (int oldtype);
+libc_hidden_proto (__pthread_disable_asynccancel)
+#define LIBC_CANCEL_RESET(oldtype) __pthread_disable_asynccancel (oldtype)
 
 #endif