glibc/sysdeps/unix/sysv/linux/tile/makecontext.c

68 lines
2.0 KiB
C

/* Copyright (C) 2011-2017 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Chris Metcalf <cmetcalf@tilera.com>, 2011.
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
<http://www.gnu.org/licenses/>. */
#include <stdarg.h>
#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include <ucontext.h>
#include <arch/abi.h>
void
__makecontext (ucontext_t *ucp, void (*func) (void), int argc, ...)
{
extern void __startcontext (void);
uint_reg_t *sp, *args;
va_list ap;
int i;
/* Initialize the top of stack. */
sp = (uint_reg_t *) ((((intptr_t) ucp->uc_stack.ss_sp
+ ucp->uc_stack.ss_size) & -16L) - 16);
/* Allow room for memory-passed arguments if necessary. */
if (argc > 10)
sp -= 2 + (argc - 10);
sp[0] = sp[1] = 0;
/* Set parameters. */
va_start (ap, argc);
args = &ucp->uc_mcontext.gregs[0];
for (i = 0; i < argc; i++)
{
if (i == 10)
args = &sp[2];
*args++ = va_arg (ap, long);
}
va_end (ap);
/* Start in the trampoline. */
ucp->uc_mcontext.pc = (long) __startcontext;
/* Set stack pointer. */
ucp->uc_mcontext.sp = (long) sp;
/* Pass FUNC to __startcontext in r31. */
ucp->uc_mcontext.gregs[31] = (long) func;
/* Pass ucp->uc_link to __startcontext in r30. */
ucp->uc_mcontext.gregs[30] = (long) ucp->uc_link;
}
weak_alias (__makecontext, makecontext)