From ce0b7961ae400e5aeff28d54dc14955199947b74 Mon Sep 17 00:00:00 2001 From: Florian Weimer Date: Wed, 5 May 2021 17:15:57 +0200 Subject: [PATCH] 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 --- elf/Makefile | 6 ++-- manual/llio.texi | 4 +-- nptl/Makefile | 4 +-- nptl/Versions | 2 ++ nptl/cancellation.c | 4 +-- nptl/libc-cancellation.c | 24 -------------- nptl/pthreadP.h | 2 -- nptl/pthread_create.c | 4 +-- rt/Makefile | 1 - sysdeps/nptl/Makefile | 3 +- sysdeps/nptl/librt-cancellation.c | 24 -------------- sysdeps/nptl/lowlevellock-futex.h | 8 ++--- sysdeps/unix/sysv/linux/socketcall.h | 5 --- sysdeps/unix/sysv/linux/sysdep-cancel.h | 44 ++++--------------------- 14 files changed, 25 insertions(+), 110 deletions(-) delete mode 100644 nptl/libc-cancellation.c delete mode 100644 sysdeps/nptl/librt-cancellation.c diff --git a/elf/Makefile b/elf/Makefile index f09988f7d2..4f99af626f 100644 --- 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 c0a53e1a6e..cbc4909fd5 100644 --- 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 884cb69bb4..1337b9e648 100644 --- 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 ce09c73727..e845cbf804 100644 --- 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 2ee633eabc..c20845adc0 100644 --- 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 index 29f5a5864b..0000000000 --- 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 , 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 - . */ - -#include "pthreadP.h" - - -#define __pthread_enable_asynccancel __libc_enable_asynccancel -#define __pthread_disable_asynccancel __libc_disable_asynccancel -#include diff --git a/nptl/pthreadP.h b/nptl/pthreadP.h index d480639740..6b52ca158e 100644 --- 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 d89a83b38a..775287d0e4 100644 --- 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 c1a0fdeb46..97c9bbd9de 100644 --- 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 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 , 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 - . */ - -#include - - -#define __pthread_enable_asynccancel __librt_enable_asynccancel -#define __pthread_disable_asynccancel __librt_disable_asynccancel -#include 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 #include -/* 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 -- 2.43.5