pthread_exit_process
Jakub Jelinek
jakub@redhat.com
Thu Jan 11 14:30:00 GMT 2001
On Thu, Jan 11, 2001 at 11:25:19AM -0800, Ulrich Drepper wrote:
> Jakub Jelinek <jakub@redhat.com> writes:
>
> > This change breaks process-wide exit from thread other than main.
>
> Thanks for the test case, I've added it. To fix it I've done
> something different.
I was playing with this idea today as well, but it cannot work that way.
Actually, what is the functional difference between cxa_on_exit and on_exit?
It records dso handle, but nothing ever uses it, so if you dl_close
libpthread, nothing will happen and it will crash during exit() afterwards
(because it won't be removed during cxa_finalize).
And if you add ef_cxa2 to cxa_finalize, then you suddenly don't know which
value to pass to it (and even ef_cxa2 handler would not be ever called from
exit() directly, since it would be called from _*fini through cxa_finalize
first.
I believe the patch below could work, although I have not tested it yet.
Basically, it removes ef_cxa2 so that cxa_finalize does not have to do 2
compare_and_swaps and passes the status unconditionally to all ef_cxa
callbacks as hidden second argument (if you don't like this part of the
patch, it should work only with the pthread.c change).
The other change is to call __cxa*exit in pthread.c twice (unless libpthread
is built with -z nodelete in which case on_exit is enough), once from
pthread_initialize (ie. early) and once from __pthread_initialize_manager
(ie. late). The late callback which will be called earlier (even before
atexit _fini and _dl_fini) will just record the retcode value which the
earlier callback (called probably from __cxa_finalize when it has no idea on
what status is) will use for its dirty work.
2001-01-11 Jakub Jelinek <jakub@redhat.com>
* stdlib/cxa_atexit.c (__cxa_atexit): Cast to (void *, int) func.
* stdlib/cxa_finalize.c (__cxa_finalize): Add hidden second argument.
* stdlib/cxa_on_exit.c: Remove.
* stdlib/Makefile, stdlib/Versions, include/stdlib.h: Revert last
patch.
* stdlib/exit.h: Revert last patch.
(struct exit_function): Add second argument to cxa fn.
* stdlib/exit.c: Revert last patch.
(exit): Add hidden second argument.
* Makefile (CFLAGS-pthread.c): Pass -DHAVE_Z_NODELETE if ld supports
-z nodelete.
* pthread.c (pthread_exit_process) Rename to...
(pthread_onexit_process): ...this.
(pthread_atexit_process, pthread_atexit_retcode): New.
(pthread_initialize): Call __cxa_atexit instead of __cxa_on_exit
and only if HAVE_Z_NODELETE is not defined.
(__pthread_initialize_manager): Register pthread_atexit_retcode
with __cxa_atexit.
--- libc/include/stdlib.h.jj Fri Jan 12 00:08:29 2001
+++ libc/include/stdlib.h Fri Jan 12 00:09:29 2001
@@ -55,7 +55,6 @@ extern void _quicksort (void *const pbas
size_t size, __compar_fn_t cmp);
extern int __cxa_atexit (void (*func) (void *), void *arg, void *d);
-extern int __cxa_on_exit (void (*func) (int, void *), void *arg, void *d);
extern void __cxa_finalize (void *d);
--- libc/linuxthreads/Makefile.jj Thu Jan 11 23:31:06 2001
+++ libc/linuxthreads/Makefile Thu Jan 11 23:31:14 2001
@@ -54,9 +54,10 @@ endif
include ../Rules
+znodelete-yes = -DHAVE_Z_NODELETE
CFLAGS-mutex.c += -D__NO_WEAK_PTHREAD_ALIASES
CFLAGS-specific.c += -D__NO_WEAK_PTHREAD_ALIASES
-CFLAGS-pthread.c += -D__NO_WEAK_PTHREAD_ALIASES
+CFLAGS-pthread.c += -D__NO_WEAK_PTHREAD_ALIASES $(znodelete-$(have-z-nodelete))
CFLAGS-ptfork.c += -D__NO_WEAK_PTHREAD_ALIASES
CFLAGS-cancel.c += -D__NO_WEAK_PTHREAD_ALIASES
CFLAGS-unload.c += -DPREFIX=\"$(objpfx)\"
--- libc/linuxthreads/pthread.c.jj Thu Jan 11 23:09:29 2001
+++ libc/linuxthreads/pthread.c Thu Jan 11 23:59:29 2001
@@ -216,7 +216,11 @@ const int __linuxthread_pthread_sizeof_d
/* Forward declarations */
-static void pthread_exit_process(int retcode, void *arg);
+static void pthread_onexit_process(int retcode, void *arg);
+#ifndef HAVE_Z_NODELETE
+static void pthread_atexit_process(void *arg, int retcode);
+static void pthread_atexit_retcode(void *arg, int retcode);
+#endif
static void pthread_handle_sigcancel(int sig);
static void pthread_handle_sigrestart(int sig);
static void pthread_handle_sigdebug(int sig);
@@ -433,12 +437,14 @@ static void pthread_initialize(void)
sigprocmask(SIG_BLOCK, &mask, NULL);
/* Register an exit function to kill all other threads. */
/* Do it early so that user-registered atexit functions are called
- before pthread_exit_process. */
+ before pthread_*exit_process. */
+#ifndef HAVE_Z_NODELETE
if (__builtin_expect (&__dso_handle != NULL, 1))
- __cxa_on_exit((void (*) (void *)) pthread_exit_process, NULL,
+ __cxa_atexit ((void (*) (void *)) pthread_atexit_process, NULL,
__dso_handle);
else
- __on_exit (pthread_exit_process, NULL);
+#endif
+ __on_exit (pthread_onexit_process, NULL);
/* How many processors. */
__pthread_smp_kernel = is_smp_system ();
}
@@ -456,6 +462,12 @@ int __pthread_initialize_manager(void)
struct rlimit limit;
int max_stack;
+#ifndef HAVE_Z_NODELETE
+ if (__builtin_expect (&__dso_handle != NULL, 1))
+ __cxa_atexit ((void (*) (void *)) pthread_atexit_retcode, NULL,
+ __dso_handle);
+#endif
+
getrlimit(RLIMIT_STACK, &limit);
#ifdef FLOATING_STACKS
if (limit.rlim_cur == RLIM_INFINITY)
@@ -723,7 +735,7 @@ weak_alias (__pthread_yield, pthread_yie
/* Process-wide exit() request */
-static void pthread_exit_process(int retcode, void *arg)
+static void pthread_onexit_process(int retcode, void *arg)
{
if (__builtin_expect (__pthread_manager_request, 0) >= 0) {
struct pthread_request request;
@@ -744,6 +756,20 @@ static void pthread_exit_process(int ret
}
}
}
+
+#ifndef HAVE_Z_NODELETE
+static int __pthread_atexit_retcode;
+
+static void pthread_atexit_process(void *arg, int retcode)
+{
+ pthread_onexit_process (retcode ?: __pthread_atexit_retcode, arg);
+}
+
+static void pthread_atexit_retcode(void *arg, int retcode)
+{
+ __pthread_atexit_retcode = retcode;
+}
+#endif
/* The handler for the RESTART signal just records the signal received
in the thread descriptor, and optionally performs a siglongjmp
--- libc/stdlib/Makefile.jj Thu Jan 11 23:07:36 2001
+++ libc/stdlib/Makefile Thu Jan 11 23:36:43 2001
@@ -1,4 +1,4 @@
-# Copyright (C) 1991-1999, 2000, 2001 Free Software Foundation, Inc.
+# Copyright (C) 1991-1999, 2000 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
@@ -29,7 +29,7 @@ routines := \
abort \
bsearch qsort msort \
getenv putenv setenv secure-getenv \
- exit on_exit atexit cxa_atexit cxa_on_exit cxa_finalize \
+ exit on_exit atexit cxa_atexit cxa_finalize \
abs labs llabs \
div ldiv lldiv \
mblen mbstowcs mbtowc wcstombs wctomb \
--- libc/stdlib/Versions.jj Thu Jan 11 23:07:36 2001
+++ libc/stdlib/Versions Thu Jan 11 23:36:43 2001
@@ -94,8 +94,4 @@ libc {
# used by new G++ ABI
__cxa_atexit; __cxa_finalize;
}
- GLIBC_2.2.1 {
- # used in the thread library
- __cxa_on_exit;
- }
}
--- libc/stdlib/exit.c.jj Thu Jan 11 23:07:36 2001
+++ libc/stdlib/exit.c Thu Jan 11 23:37:45 2001
@@ -57,10 +57,7 @@ exit (int status)
(*f->func.at) ();
break;
case ef_cxa:
- (*f->func.cxa.fn) (f->func.cxa.arg);
- break;
- case ef_cxa2:
- (*f->func.cxa2.fn) (status, f->func.cxa2.arg);
+ (*f->func.cxa.fn) (f->func.cxa.arg, status);
break;
}
}
--- libc/stdlib/exit.h.jj Thu Jan 11 23:07:36 2001
+++ libc/stdlib/exit.h Thu Jan 11 23:40:11 2001
@@ -26,8 +26,7 @@ enum
ef_us,
ef_on,
ef_at,
- ef_cxa,
- ef_cxa2
+ ef_cxa
};
struct exit_function
@@ -45,16 +44,10 @@ struct exit_function
} on;
struct
{
- void (*fn) (void *arg);
+ void (*fn) (void *arg, int status);
void *arg;
void *dso_handle;
} cxa;
- struct
- {
- void (*fn) (int status, void *arg);
- void *arg;
- void *dso_handle;
- } cxa2;
} func;
};
struct exit_function_list
--- libc/stdlib/cxa_on_exit.c.jj Thu Jan 11 20:22:45 2001
+++ libc/stdlib/cxa_on_exit.c Thu Jan 11 23:37:06 2001
@@ -1,38 +0,0 @@
-/* Copyright (C) 2001 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 Library General Public License as
- published by the Free Software Foundation; either version 2 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
- Library General Public License for more details.
-
- You should have received a copy of the GNU Library General Public
- License along with the GNU C Library; see the file COPYING.LIB. If not,
- write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
- Boston, MA 02111-1307, USA. */
-
-#include <stdlib.h>
-#include "exit.h"
-
-/* Register a function to be called by exit or when a shared library
- is unloaded. This function is only called from code generated by
- the C++ compiler. */
-int
-__cxa_on_exit (void (*func) (int, void *), void *arg, void *d)
-{
- struct exit_function *new = __new_exitfn ();
-
- if (new == NULL)
- return -1;
-
- new->flavor = ef_cxa2;
- new->func.cxa2.fn = func;
- new->func.cxa2.arg = arg;
- new->func.cxa2.dso_handle = d;
- return 0;
-}
--- libc/stdlib/cxa_finalize.c.jj Mon Dec 27 22:47:52 1999
+++ libc/stdlib/cxa_finalize.c Thu Jan 11 23:38:32 2001
@@ -1,4 +1,4 @@
-/* Copyright (C) 1999 Free Software Foundation, Inc.
+/* Copyright (C) 1999, 2001 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
@@ -39,6 +39,6 @@ __cxa_finalize (void *d)
if (d == f->func.cxa.dso_handle
/* We don't want to run this cleanup more than once. */
&& compare_and_swap (&f->flavor, ef_cxa, ef_free))
- (*f->func.cxa.fn) (f->func.cxa.arg);
+ (*f->func.cxa.fn) (f->func.cxa.arg, 0);
}
}
--- libc/stdlib/cxa_atexit.c.jj Mon Dec 27 22:47:26 1999
+++ libc/stdlib/cxa_atexit.c Thu Jan 11 23:39:17 2001
@@ -1,4 +1,4 @@
-/* Copyright (C) 1999 Free Software Foundation, Inc.
+/* Copyright (C) 1999, 2001 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
@@ -31,7 +31,7 @@ __cxa_atexit (void (*func) (void *), voi
return -1;
new->flavor = ef_cxa;
- new->func.cxa.fn = func;
+ new->func.cxa.fn = (void (*) (void *, int)) func;
new->func.cxa.arg = arg;
new->func.cxa.dso_handle = d;
return 0;
Jakub
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