[PATCH 02/11] nptl: Consolidate aysnc cancel enable/disable implementation in libc
Florian Weimer
fweimer@redhat.com
Mon May 3 13:51:32 GMT 2021
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.
---
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 <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 ee77928fc7..2d9e42173e 100644
--- a/nptl/pthreadP.h
+++ b/nptl/pthreadP.h
@@ -569,8 +569,6 @@ 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 <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
--
2.30.2
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