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>

diff --git a/elf/Makefile b/elf/Makefile
index f09988f..4f99af6 100644 (file)
--- a/elf/Makefile
+++ b/elf/Makefile
@@ -528,8 +528,10 @@ $(objpfx)dl-allobjs.os: $(all-rtld-routines:%=$(objpfx)%.os)
 # discovery mechanism is not compatible with the libc implementation
 # when compiled for libc.
 rtld-stubbed-symbols = \
-  __libc_disable_asynccancel \
-  __libc_enable_asynccancel \
+  __GI___pthread_disable_asynccancel \
+  __GI___pthread_enable_asynccancel \
+  __pthread_disable_asynccancel \
+  __pthread_enable_asynccancel \
   calloc \
   free \
   malloc \

diff --git a/manual/llio.texi b/manual/llio.texi
index c0a53e1..cbc4909 100644 (file)
--- a/manual/llio.texi
+++ b/manual/llio.texi
@@ -2534,13 +2534,13 @@ aiocb64}, since the LFS transparently replaces the old interface.
 @c     sigemptyset ok
 @c     sigaddset ok
 @c     setjmp ok
-@c     CANCEL_ASYNC -> pthread_enable_asynccancel ok
+@c     LIBC_CANCEL_ASYNC -> __pthread_enable_asynccancel ok
 @c      do_cancel ok
 @c       pthread_unwind ok
 @c        Unwind_ForcedUnwind or longjmp ok [@ascuheap @acsmem?]
 @c     lll_lock @asulock @aculock
 @c     lll_unlock @asulock @aculock
-@c     CANCEL_RESET -> pthread_disable_asynccancel ok
+@c     LIBC_CANCEL_RESET -> __pthread_disable_asynccancel ok
 @c      lll_futex_wait ok
 @c     ->start_routine ok -----
 @c     call_tls_dtors @asulock @ascuheap @aculock @acsmem

diff --git a/nptl/Makefile b/nptl/Makefile
index 884cb69..1337b9e 100644 (file)
--- a/nptl/Makefile
+++ b/nptl/Makefile
@@ -30,6 +30,7 @@ extra-libs-others := $(extra-libs)
 
 routines = \
   alloca_cutoff \
+  cancellation \
   cleanup_compat \
   cleanup_defer_compat \
   cleanup_routine \
@@ -39,7 +40,6 @@ routines = \
   elision-trylock \
   elision-unlock \
   futex-internal \
-  libc-cancellation \
   libc-cleanup \
   libc_multiple_threads \
   libc_pthread_init \
@@ -157,7 +157,6 @@ shared-only-routines = forward
 static-only-routines = pthread_atfork
 
 libpthread-routines = \
-  cancellation \
   cleanup \
   cleanup_defer \
   events \
@@ -239,7 +238,6 @@ CFLAGS-pthread_setcanceltype.c += -fexceptions -fasynchronous-unwind-tables
 # These are internal functions which similar functionality as setcancelstate
 # and setcanceltype.
 CFLAGS-cancellation.c += -fasynchronous-unwind-tables
-CFLAGS-libc-cancellation.c += -fasynchronous-unwind-tables
 
 # Calling pthread_exit() must cause the registered cancel handlers to
 # be executed.  Therefore exceptions have to be thrown through this

diff --git a/nptl/Versions b/nptl/Versions
index ce09c73..e845cbf 100644 (file)
--- a/nptl/Versions
+++ b/nptl/Versions
@@ -281,6 +281,8 @@ libc {
     __pthread_cleanup_push;
     __pthread_cleanup_upto;
     __pthread_current_priority;
+    __pthread_disable_asynccancel;
+    __pthread_enable_asynccancel;
     __pthread_force_elision;
     __pthread_getattr_default_np;
     __pthread_keys;

diff --git a/nptl/cancellation.c b/nptl/cancellation.c
index 2ee633e..c20845a 100644 (file)
--- a/nptl/cancellation.c
+++ b/nptl/cancellation.c
@@ -28,7 +28,6 @@
    AS-safe, with the exception of the actual cancellation, because they
    are called by wrappers around AS-safe functions like write().*/
 int
-attribute_hidden
 __pthread_enable_asynccancel (void)
 {
   struct pthread *self = THREAD_SELF;
@@ -60,11 +59,11 @@ __pthread_enable_asynccancel (void)
 
   return oldval;
 }
+libc_hidden_def (__pthread_enable_asynccancel)
 
 /* See the comment for __pthread_enable_asynccancel regarding
    the AS-safety of this function.  */
 void
-attribute_hidden
 __pthread_disable_asynccancel (int oldtype)
 {
   /* If asynchronous cancellation was enabled before we do not have
@@ -102,3 +101,4 @@ __pthread_disable_asynccancel (int oldtype)
       newval = THREAD_GETMEM (self, cancelhandling);
     }
 }
+libc_hidden_def (__pthread_disable_asynccancel)

diff --git a/nptl/libc-cancellation.c b/nptl/libc-cancellation.c
deleted file mode 100644 (file)
index 29f5a58..0000000
--- a/nptl/libc-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 "pthreadP.h"
-
-
-#define __pthread_enable_asynccancel __libc_enable_asynccancel
-#define __pthread_disable_asynccancel __libc_disable_asynccancel
-#include <nptl/cancellation.c>

diff --git a/nptl/pthreadP.h b/nptl/pthreadP.h
index d480639..6b52ca1 100644 (file)
--- a/nptl/pthreadP.h
+++ b/nptl/pthreadP.h
@@ -567,8 +567,6 @@ libc_hidden_proto (__pthread_exit)
 extern int __pthread_join (pthread_t threadid, void **thread_return);
 extern int __pthread_setcanceltype (int type, int *oldtype);
 libc_hidden_proto (__pthread_setcanceltype)
-extern int __pthread_enable_asynccancel (void) attribute_hidden;
-extern void __pthread_disable_asynccancel (int oldtype) attribute_hidden;
 extern void __pthread_testcancel (void);
 libc_hidden_proto (__pthread_testcancel)
 extern int __pthread_clockjoin_ex (pthread_t, void **, clockid_t,

diff --git a/nptl/pthread_create.c b/nptl/pthread_create.c
index d89a83b..775287d 100644 (file)
--- a/nptl/pthread_create.c
+++ b/nptl/pthread_create.c
@@ -353,7 +353,7 @@ START_THREAD_DEFN
         have ownership (see CONCURRENCY NOTES above).  */
       if (__glibc_unlikely (pd->stopped_start))
        {
-         int oldtype = CANCEL_ASYNC ();
+         int oldtype = LIBC_CANCEL_ASYNC ();
 
          /* Get the lock the parent locked to force synchronization.  */
          lll_lock (pd->lock, LLL_PRIVATE);
@@ -363,7 +363,7 @@ START_THREAD_DEFN
          /* And give it up right away.  */
          lll_unlock (pd->lock, LLL_PRIVATE);
 
-         CANCEL_RESET (oldtype);
+         LIBC_CANCEL_RESET (oldtype);
        }
 
       LIBC_PROBE (pthread_start, 3, (pthread_t) pd, pd->start_routine, pd->arg);

diff --git a/rt/Makefile b/rt/Makefile
index c1a0fde..97c9bbd 100644 (file)
--- a/rt/Makefile
+++ b/rt/Makefile
@@ -59,7 +59,6 @@ include ../Rules
 CFLAGS-aio_suspend.c += -fexceptions
 CFLAGS-mq_timedreceive.c += -fexceptions -fasynchronous-unwind-tables
 CFLAGS-mq_timedsend.c += -fexceptions -fasynchronous-unwind-tables
-CFLAGS-librt-cancellation.c += -fasynchronous-unwind-tables
 
 LDFLAGS-rt.so = -Wl,--enable-new-dtags,-z,nodelete
 

diff --git a/sysdeps/nptl/Makefile b/sysdeps/nptl/Makefile
index adcced4..632cd36 100644 (file)
--- 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 (file)
index 1ad0eb1..0000000
--- 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 ca96397..66ebfe5 100644 (file)
--- 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 07702fc..3084623 100644 (file)
--- 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 da2f08f..c64cfff 100644 (file)
--- 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