165 lines
4.8 KiB
C
165 lines
4.8 KiB
C
/* Thread library support for -fsplit-stack. */
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/* Copyright (C) 2009, 2010, 2011 Free Software Foundation, Inc.
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Contributed by Ian Lance Taylor <iant@google.com>.
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This file is part of GCC.
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GCC is free software; you can redistribute it and/or modify it under
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the terms of the GNU General Public License as published by the Free
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Software Foundation; either version 3, or (at your option) any later
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version.
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GCC is distributed in the hope that it will be useful, but WITHOUT ANY
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WARRANTY; without even the implied warranty of MERCHANTABILITY or
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FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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for more details.
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Under Section 7 of GPL version 3, you are granted additional
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permissions described in the GCC Runtime Library Exception, version
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3.1, as published by the Free Software Foundation.
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You should have received a copy of the GNU General Public License and
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a copy of the GCC Runtime Library Exception along with this program;
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see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
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<http://www.gnu.org/licenses/>. */
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#include "tconfig.h"
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#include "tsystem.h"
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#include "coretypes.h"
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#include "tm.h"
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#include "libgcc_tm.h"
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/* If inhibit_libc is defined, we can not compile this file. The
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effect is that people will not be able to use -fsplit-stack. That
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is much better than failing the build particularly since people
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will want to define inhibit_libc while building a compiler which
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can build glibc. */
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#ifndef inhibit_libc
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#include <errno.h>
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#include <pthread.h>
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#include "generic-morestack.h"
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/* We declare the pthread functions we need as weak, so that
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libgcc_s.so does not need to be linked against -lpthread. */
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extern int pthread_once (pthread_once_t *, void (*) (void))
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__attribute__ ((weak));
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extern int pthread_key_create (pthread_key_t *, void (*) (void *))
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__attribute__ ((weak));
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extern int pthread_setspecific (pthread_key_t, const void *)
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__attribute__ ((weak));
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/* The key for the list of stack segments to free when the thread
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exits. This is created by pthread_key_create. */
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static pthread_key_t segment_list_key;
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/* Used to only run create_key once. */
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static pthread_once_t create_key_once = PTHREAD_ONCE_INIT;
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/* Release all the segments for a thread. This is the destructor
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function used by pthread_key_create, and is called when a thread
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exits. */
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static void
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free_segments (void* arg)
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{
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__morestack_release_segments ((struct stack_segment **) arg, 1);
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}
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/* Set up the key for the list of segments. This is called via
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pthread_once. */
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static void
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create_key (void)
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{
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int err;
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err = pthread_key_create (&segment_list_key, free_segments);
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if (err != 0)
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{
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static const char msg[] = "pthread_key_create failed: errno ";
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__morestack_fail (msg, sizeof msg - 1, err);
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}
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}
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/* Pass information from the pthread_create wrapper to
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stack_split_initialize_thread. */
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struct pthread_create_args
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{
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void *(*start_routine) (void *);
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void *arg;
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};
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/* Initialize a thread. This is called via pthread_create. It calls
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a target dependent function to set up any required stack guard. */
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static void* stack_split_initialize_thread (void *)
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__attribute__ ((no_split_stack));
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static void *
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stack_split_initialize_thread (void *varg)
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{
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struct pthread_create_args *args = (struct pthread_create_args *) varg;
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int err;
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void *(*start_routine) (void *);
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void *arg;
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__stack_split_initialize ();
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err = pthread_setspecific (segment_list_key, (void *) &__morestack_segments);
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if (err != 0)
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{
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static const char msg[] = "pthread_setspecific failed: errno ";
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__morestack_fail (msg, sizeof msg - 1, err);
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}
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start_routine = args->start_routine;
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arg = args->arg;
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free (args);
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return (*start_routine) (arg);
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}
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/* This function wraps calls to pthread_create to make sure that the
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stack guard is initialized for new threads. FIXME: This hack will
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not be necessary if glibc supports -fsplit-stack directly. */
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int __wrap_pthread_create (pthread_t *, const pthread_attr_t *,
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void *(*start_routine) (void *), void *)
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__attribute__ ((visibility ("hidden")));
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extern int __real_pthread_create (pthread_t *, const pthread_attr_t *,
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void *(*start_routine) (void *), void *)
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__attribute__ ((weak));
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int
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__wrap_pthread_create (pthread_t *tid, const pthread_attr_t *attr,
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void *(*start_routine) (void *), void *arg)
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{
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int err;
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struct pthread_create_args* args;
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err = pthread_once (&create_key_once, create_key);
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if (err != 0)
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{
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static const char msg[] = "pthread_once failed: errno ";
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__morestack_fail (msg, sizeof msg - 1, err);
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}
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args = malloc (sizeof (struct pthread_create_args));
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if (args == NULL)
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return EAGAIN;
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args->start_routine = start_routine;
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args->arg = arg;
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return __real_pthread_create (tid, attr, stack_split_initialize_thread, args);
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}
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#endif /* !defined (inhibit_libc) */
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