123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178 |
- /* Thread library support for -fsplit-stack. */
- /* Copyright (C) 2009-2022 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 cannot 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 <signal.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));
- extern int pthread_sigmask (int, const sigset_t *, sigset_t *)
- __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)
- {
- /* We must block signals in case the signal handler tries to split
- the stack. We leave them blocked while the thread exits. */
- if (pthread_sigmask)
- {
- sigset_t mask;
- sigfillset (&mask);
- pthread_sigmask (SIG_BLOCK, &mask, NULL);
- }
- __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) */
|