diff options
Diffstat (limited to 'lib/libc/arm/gen/makecontext.c')
| -rw-r--r-- | lib/libc/arm/gen/makecontext.c | 94 |
1 files changed, 94 insertions, 0 deletions
diff --git a/lib/libc/arm/gen/makecontext.c b/lib/libc/arm/gen/makecontext.c new file mode 100644 index 000000000000..18aadf100fc9 --- /dev/null +++ b/lib/libc/arm/gen/makecontext.c @@ -0,0 +1,94 @@ +/* $NetBSD: makecontext.c,v 1.2 2003/01/18 11:06:24 thorpej Exp $ */ + +/*- + * Copyright (c) 2001 The NetBSD Foundation, Inc. + * All rights reserved. + * + * This code is derived from software contributed to The NetBSD Foundation + * by Klaus Klein. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. All advertising materials mentioning features or use of this software + * must display the following acknowledgement: + * This product includes software developed by the NetBSD + * Foundation, Inc. and its contributors. + * 4. Neither the name of The NetBSD Foundation nor the names of its + * contributors may be used to endorse or promote products derived + * from this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS + * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED + * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR + * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS + * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + */ + +#include <sys/cdefs.h> +__FBSDID("$FreeBSD$"); + +#include <stdlib.h> +#include <stddef.h> +#include <inttypes.h> +#include <ucontext.h> + +#include <stdarg.h> + +extern void _ctx_start(ucontext_t *, int argc, ...); + +void +ctx_done(ucontext_t *ucp) +{ + + if (ucp->uc_link == NULL) + exit(0); + else { + setcontext((const ucontext_t *)ucp->uc_link); + abort(); + } +} + +__weak_reference(__makecontext, makecontext); + +void +__makecontext(ucontext_t *ucp, void (*func)(void), int argc, ...) +{ + __greg_t *gr = ucp->uc_mcontext.__gregs; + int i; + unsigned int *sp; + va_list ap; + + /* Compute and align stack pointer. */ + sp = (unsigned int *) + (((uintptr_t)ucp->uc_stack.ss_sp + ucp->uc_stack.ss_size) & ~7); + /* Allocate necessary stack space for arguments exceeding r0-3. */ + if (argc > 4) + sp -= argc - 4; + gr[_REG_SP] = (__greg_t)sp; + /* Wipe out frame pointer. */ + gr[_REG_FP] = 0; + /* Arrange for return via the trampoline code. */ + gr[_REG_LR] = (__greg_t)_ctx_start; + gr[_REG_PC] = (__greg_t)func; + + va_start(ap, argc); + /* Pass up to four arguments in r0-3. */ + for (i = 0; i < argc && i < 4; i++) + gr[_REG_R0 + i] = va_arg(ap, int); + /* Pass any additional arguments on the stack. */ + for (argc -= i; argc > 0; argc--) + *sp++ = va_arg(ap, int); + va_end(ap); +} |