b16fa5e718
This implementation spills additional arguments on the stack so works fine with more than 6 arguments. I believe the check was just copied over from sparc64 (which doesn't support spilling onto the stack) Sponsored by: DARPA / AFRL
123 lines
3.8 KiB
C
123 lines
3.8 KiB
C
/* $NetBSD: makecontext.c,v 1.5 2009/12/14 01:07:42 matt Exp $ */
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/*-
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* SPDX-License-Identifier: BSD-2-Clause-NetBSD
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*
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* Copyright (c) 2001 The NetBSD Foundation, Inc.
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* All rights reserved.
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*
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* This code is derived from software contributed to The NetBSD Foundation
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* by Klaus Klein.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
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* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
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* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
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* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*/
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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#if defined(LIBC_SCCS) && !defined(lint)
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__RCSID("$NetBSD: makecontext.c,v 1.5 2009/12/14 01:07:42 matt Exp $");
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#endif
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#include <sys/param.h>
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#include <machine/abi.h>
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#include <machine/regnum.h>
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#include <stdarg.h>
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#include <stdlib.h>
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#include <unistd.h>
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#include <stdio.h>
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#include <ucontext.h>
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__weak_reference(__makecontext, makecontext);
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void _ctx_done(ucontext_t *);
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void _ctx_start(void);
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void
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__makecontext(ucontext_t *ucp, void (*func)(void), int argc, ...)
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{
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mcontext_t *mc;
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register_t *sp;
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int i;
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va_list ap;
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/*
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* XXX/juli
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* We need an mc_len or mc_flags like other architectures
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* so that we can mark a context as invalid. Store it in
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* mc->mc_regs[ZERO] perhaps?
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*/
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if (argc < 0 || ucp == NULL ||
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ucp->uc_stack.ss_sp == NULL ||
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ucp->uc_stack.ss_size < MINSIGSTKSZ)
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return;
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mc = &ucp->uc_mcontext;
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sp = (register_t *)
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((uintptr_t)ucp->uc_stack.ss_sp + ucp->uc_stack.ss_size);
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#if defined(__mips_o32) || defined(__mips_o64)
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sp -= (argc >= 4 ? argc : 4); /* Make room for >=4 arguments. */
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#elif defined(__mips_n32) || defined(__mips_n64)
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sp -= (argc > 8 ? argc - 8 : 0); /* Make room for > 8 arguments. */
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#endif
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sp = (register_t *)((uintptr_t)sp & ~(STACK_ALIGN - 1));
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mc->mc_regs[SP] = (intptr_t)sp;
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mc->mc_regs[S0] = (intptr_t)ucp;
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mc->mc_regs[T9] = (intptr_t)func;
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mc->mc_pc = (intptr_t)_ctx_start;
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/* Construct argument list. */
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va_start(ap, argc);
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#if defined(__mips_o32) || defined(__mips_o64)
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/* Up to the first four arguments are passed in $a0-3. */
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for (i = 0; i < argc && i < 4; i++)
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/* LINTED register_t is safe */
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mc->mc_regs[A0 + i] = va_arg(ap, register_t);
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/* Skip over the $a0-3 gap. */
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sp += 4;
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#endif
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#if defined(__mips_n32) || defined(__mips_n64)
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/* Up to the first 8 arguments are passed in $a0-7. */
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for (i = 0; i < argc && i < 8; i++)
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/* LINTED register_t is safe */
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mc->mc_regs[A0 + i] = va_arg(ap, register_t);
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#endif
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/* Pass remaining arguments on the stack. */
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for (; i < argc; i++)
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/* LINTED register_t is safe */
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*sp++ = va_arg(ap, register_t);
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va_end(ap);
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}
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void
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_ctx_done(ucontext_t *ucp)
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{
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if (ucp->uc_link == NULL)
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exit(0);
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else {
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setcontext((const ucontext_t *)ucp->uc_link);
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abort();
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}
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}
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