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-rw-r--r--gcc-4.9/libgcc/generic-morestack-thread.c164
1 files changed, 164 insertions, 0 deletions
diff --git a/gcc-4.9/libgcc/generic-morestack-thread.c b/gcc-4.9/libgcc/generic-morestack-thread.c
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index 000000000..8b571a7cf
--- /dev/null
+++ b/gcc-4.9/libgcc/generic-morestack-thread.c
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+/* Thread library support for -fsplit-stack. */
+/* Copyright (C) 2009-2014 Free Software Foundation, Inc.
+ Contributed by Ian Lance Taylor <iant@google.com>.
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free
+Software Foundation; either version 3, or (at your option) any later
+version.
+
+GCC 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 General Public License
+for more details.
+
+Under Section 7 of GPL version 3, you are granted additional
+permissions described in the GCC Runtime Library Exception, version
+3.1, as published by the Free Software Foundation.
+
+You should have received a copy of the GNU General Public License and
+a copy of the GCC Runtime Library Exception along with this program;
+see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
+<http://www.gnu.org/licenses/>. */
+
+#include "tconfig.h"
+#include "tsystem.h"
+#include "coretypes.h"
+#include "tm.h"
+#include "libgcc_tm.h"
+
+/* If inhibit_libc is defined, we can not compile this file. The
+ effect is that people will not be able to use -fsplit-stack. That
+ is much better than failing the build particularly since people
+ will want to define inhibit_libc while building a compiler which
+ can build glibc. */
+
+#ifndef inhibit_libc
+
+#include <errno.h>
+#include <pthread.h>
+
+#include "generic-morestack.h"
+
+/* We declare the pthread functions we need as weak, so that
+ libgcc_s.so does not need to be linked against -lpthread. */
+
+extern int pthread_once (pthread_once_t *, void (*) (void))
+ __attribute__ ((weak));
+
+extern int pthread_key_create (pthread_key_t *, void (*) (void *))
+ __attribute__ ((weak));
+
+extern int pthread_setspecific (pthread_key_t, const void *)
+ __attribute__ ((weak));
+
+/* The key for the list of stack segments to free when the thread
+ exits. This is created by pthread_key_create. */
+
+static pthread_key_t segment_list_key;
+
+/* Used to only run create_key once. */
+
+static pthread_once_t create_key_once = PTHREAD_ONCE_INIT;
+
+/* Release all the segments for a thread. This is the destructor
+ function used by pthread_key_create, and is called when a thread
+ exits. */
+
+static void
+free_segments (void* arg)
+{
+ __morestack_release_segments ((struct stack_segment **) arg, 1);
+}
+
+/* Set up the key for the list of segments. This is called via
+ pthread_once. */
+
+static void
+create_key (void)
+{
+ int err;
+
+ err = pthread_key_create (&segment_list_key, free_segments);
+ if (err != 0)
+ {
+ static const char msg[] = "pthread_key_create failed: errno ";
+ __morestack_fail (msg, sizeof msg - 1, err);
+ }
+}
+
+/* Pass information from the pthread_create wrapper to
+ stack_split_initialize_thread. */
+
+struct pthread_create_args
+{
+ void *(*start_routine) (void *);
+ void *arg;
+};
+
+/* Initialize a thread. This is called via pthread_create. It calls
+ a target dependent function to set up any required stack guard. */
+
+static void* stack_split_initialize_thread (void *)
+ __attribute__ ((no_split_stack));
+
+static void *
+stack_split_initialize_thread (void *varg)
+{
+ struct pthread_create_args *args = (struct pthread_create_args *) varg;
+ int err;
+ void *(*start_routine) (void *);
+ void *arg;
+
+ __stack_split_initialize ();
+
+ err = pthread_setspecific (segment_list_key, (void *) &__morestack_segments);
+ if (err != 0)
+ {
+ static const char msg[] = "pthread_setspecific failed: errno ";
+ __morestack_fail (msg, sizeof msg - 1, err);
+ }
+
+ start_routine = args->start_routine;
+ arg = args->arg;
+ free (args);
+ return (*start_routine) (arg);
+}
+
+/* This function wraps calls to pthread_create to make sure that the
+ stack guard is initialized for new threads. FIXME: This hack will
+ not be necessary if glibc supports -fsplit-stack directly. */
+
+int __wrap_pthread_create (pthread_t *, const pthread_attr_t *,
+ void *(*start_routine) (void *), void *)
+ __attribute__ ((visibility ("hidden")));
+
+extern int __real_pthread_create (pthread_t *, const pthread_attr_t *,
+ void *(*start_routine) (void *), void *)
+ __attribute__ ((weak));
+
+int
+__wrap_pthread_create (pthread_t *tid, const pthread_attr_t *attr,
+ void *(*start_routine) (void *), void *arg)
+{
+ int err;
+ struct pthread_create_args* args;
+
+ err = pthread_once (&create_key_once, create_key);
+ if (err != 0)
+ {
+ static const char msg[] = "pthread_once failed: errno ";
+ __morestack_fail (msg, sizeof msg - 1, err);
+ }
+
+ args = malloc (sizeof (struct pthread_create_args));
+ if (args == NULL)
+ return EAGAIN;
+ args->start_routine = start_routine;
+ args->arg = arg;
+ return __real_pthread_create (tid, attr, stack_split_initialize_thread, args);
+}
+
+#endif /* !defined (inhibit_libc) */