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/*
* Copyright (c) 2003 Marcel Moolenaar
* All rights reserved.
*
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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 <sys/types.h>
#include <sys/ucontext.h>
#include <machine/fpu.h>
#include <stdarg.h>
#include <stdio.h>
struct fdesc {
uint64_t ip;
uint64_t gp;
};
typedef void (*func_t)(uint64_t, uint64_t, uint64_t, uint64_t, uint64_t,
uint64_t, uint64_t, uint64_t);
static __inline uint64_t *
spill(uint64_t *bsp, uint64_t arg)
{
*bsp++ = arg;
if (((intptr_t)bsp & 0x1ff) == 0x1f8)
*bsp++ = 0;
return (bsp);
}
static void
ctx_wrapper(ucontext_t *ucp, func_t func, uint64_t *args)
{
(*func)(args[0], args[1], args[2], args[3], args[4], args[5], args[6],
args[7]);
if (ucp->uc_link == NULL)
exit(0);
setcontext((const ucontext_t *)ucp->uc_link);
/* should never get here */
abort();
/* NOTREACHED */
}
__weak_reference(__makecontext, makecontext);
void
__makecontext(ucontext_t *ucp, void (*func)(void), int argc, ...)
{
uint64_t *args, *bsp;
va_list ap;
int i;
/*
* Drop the ball completely if something's not right. We only
* support general registers as arguments and not more than 8
* of them. Things get hairy if we need to support FP registers
* (alignment issues) or more than 8 arguments (stack based).
*/
if (argc < 0 || argc > 8 || ucp == NULL ||
ucp->uc_stack.ss_sp == NULL || (ucp->uc_stack.ss_size & 15) ||
((intptr_t)ucp->uc_stack.ss_sp & 15) ||
ucp->uc_stack.ss_size < MINSIGSTKSZ)
abort();
/*
* Copy the arguments of function 'func' onto the (memory) stack.
* Always take up space for 8 arguments.
*/
va_start(ap, argc);
args = (uint64_t*)(ucp->uc_stack.ss_sp + ucp->uc_stack.ss_size) - 8;
i = 0;
while (i < argc)
args[i++] = va_arg(ap, uint64_t);
while (i < 8)
args[i++] = 0;
va_end(ap);
/*
* Push (spill) the arguments of the context wrapper onto the register
* stack. They get loaded by the RSE on a context switch.
*/
bsp = (uint64_t*)ucp->uc_stack.ss_sp;
bsp = spill(bsp, (intptr_t)ucp);
bsp = spill(bsp, (intptr_t)func);
bsp = spill(bsp, (intptr_t)args);
/*
* Setup the MD portion of the context.
*/
memset(&ucp->uc_mcontext, 0, sizeof(ucp->uc_mcontext));
ucp->uc_mcontext.mc_special.sp = (intptr_t)args - 16;
ucp->uc_mcontext.mc_special.bspstore = (intptr_t)bsp;
ucp->uc_mcontext.mc_special.pfs = (3 << 7) | 3;
ucp->uc_mcontext.mc_special.rsc = 0xf;
ucp->uc_mcontext.mc_special.rp = ((struct fdesc*)ctx_wrapper)->ip;
ucp->uc_mcontext.mc_special.gp = ((struct fdesc*)ctx_wrapper)->gp;
ucp->uc_mcontext.mc_special.fpsr = IA64_FPSR_DEFAULT;
}
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