mirror of
https://sourceware.org/git/glibc.git
synced 2025-10-28 23:34:53 +03:00
113 lines
3.8 KiB
C
113 lines
3.8 KiB
C
/* The internal wrapper of clone and clone3.
|
|
Copyright (C) 2021-2025 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 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 <sysdep.h>
|
|
#include <stddef.h>
|
|
#include <errno.h>
|
|
#include <sched.h>
|
|
#include <clone_internal.h>
|
|
#include <libc-pointer-arith.h> /* For cast_to_pointer. */
|
|
#include <stackinfo.h> /* For _STACK_GROWS_{UP,DOWN}. */
|
|
|
|
#define CLONE_ARGS_SIZE_VER0 64 /* sizeof first published struct */
|
|
#define CLONE_ARGS_SIZE_VER1 80 /* sizeof second published struct */
|
|
#define CLONE_ARGS_SIZE_VER2 88 /* sizeof third published struct */
|
|
|
|
#define sizeof_field(TYPE, MEMBER) sizeof ((((TYPE *)0)->MEMBER))
|
|
#define offsetofend(TYPE, MEMBER) \
|
|
(offsetof (TYPE, MEMBER) + sizeof_field (TYPE, MEMBER))
|
|
|
|
_Static_assert (__alignof (struct clone_args) == 8,
|
|
"__alignof (struct clone_args) != 8");
|
|
_Static_assert (offsetofend (struct clone_args, tls) == CLONE_ARGS_SIZE_VER0,
|
|
"offsetofend (struct clone_args, tls) != CLONE_ARGS_SIZE_VER0");
|
|
_Static_assert (offsetofend (struct clone_args, set_tid_size) == CLONE_ARGS_SIZE_VER1,
|
|
"offsetofend (struct clone_args, set_tid_size) != CLONE_ARGS_SIZE_VER1");
|
|
_Static_assert (offsetofend (struct clone_args, cgroup) == CLONE_ARGS_SIZE_VER2,
|
|
"offsetofend (struct clone_args, cgroup) != CLONE_ARGS_SIZE_VER2");
|
|
_Static_assert (sizeof (struct clone_args) == CLONE_ARGS_SIZE_VER2,
|
|
"sizeof (struct clone_args) != CLONE_ARGS_SIZE_VER2");
|
|
|
|
int
|
|
__clone_internal_fallback (struct clone_args *cl_args,
|
|
int (*func) (void *arg), void *arg)
|
|
{
|
|
/* Map clone3 arguments to clone arguments. NB: No need to check
|
|
invalid clone3 specific bits in flags nor exit_signal since this
|
|
is an internal function. */
|
|
int flags = cl_args->flags | cl_args->exit_signal;
|
|
void *stack = cast_to_pointer (cl_args->stack);
|
|
int ret;
|
|
|
|
#if !_STACK_GROWS_DOWN && !_STACK_GROWS_UP
|
|
# error "Define either _STACK_GROWS_DOWN or _STACK_GROWS_UP"
|
|
#endif
|
|
|
|
#if _STACK_GROWS_DOWN
|
|
stack += cl_args->stack_size;
|
|
#endif
|
|
ret = __clone (func, stack, flags, arg,
|
|
cast_to_pointer (cl_args->parent_tid),
|
|
cast_to_pointer (cl_args->tls),
|
|
cast_to_pointer (cl_args->child_tid));
|
|
return ret;
|
|
}
|
|
|
|
int
|
|
__clone3_internal (struct clone_args *cl_args, int (*func) (void *args),
|
|
void *arg)
|
|
{
|
|
#ifdef HAVE_CLONE3_WRAPPER
|
|
# if __ASSUME_CLONE3
|
|
return __clone3 (cl_args, sizeof (*cl_args), func, arg);
|
|
# else
|
|
static int clone3_supported = 1;
|
|
if (atomic_load_relaxed (&clone3_supported) == 1)
|
|
{
|
|
int ret = __clone3 (cl_args, sizeof (*cl_args), func, arg);
|
|
if (ret != -1 || errno != ENOSYS)
|
|
return ret;
|
|
|
|
atomic_store_relaxed (&clone3_supported, 0);
|
|
}
|
|
# endif
|
|
#endif
|
|
__set_errno (ENOSYS);
|
|
return -1;
|
|
}
|
|
|
|
int
|
|
__clone_internal (struct clone_args *cl_args,
|
|
int (*func) (void *arg), void *arg)
|
|
{
|
|
#ifdef HAVE_CLONE3_WRAPPER
|
|
int saved_errno = errno;
|
|
int ret = __clone3_internal (cl_args, func, arg);
|
|
if (ret != -1 || errno != ENOSYS)
|
|
return ret;
|
|
|
|
/* NB: Restore errno since errno may be checked against non-zero
|
|
return value. */
|
|
__set_errno (saved_errno);
|
|
#endif
|
|
|
|
return __clone_internal_fallback (cl_args, func, arg);
|
|
}
|
|
|
|
libc_hidden_def (__clone_internal)
|