62 lines
1.7 KiB
C
62 lines
1.7 KiB
C
/*
|
|
* Copyright (c) 2018 Ariadne Conill <ariadne@dereferenced.org>
|
|
* Copyright (c) 2019 Bobby Bingham <koorogi@koorogi.info>
|
|
*
|
|
* Permission to use, copy, modify, and/or distribute this software for any
|
|
* purpose with or without fee is hereby granted, provided that the above
|
|
* copyright notice and this permission notice appear in all copies.
|
|
*
|
|
* This software is provided 'as is' and without any warranty, express or
|
|
* implied. In no event shall the authors be liable for any damages arising
|
|
* from the use of this software.
|
|
*/
|
|
|
|
#include <stdarg.h>
|
|
#include <stdint.h>
|
|
|
|
|
|
#include "defs.h"
|
|
#include <libucontext/libucontext.h>
|
|
|
|
|
|
extern void libucontext_trampoline(void);
|
|
|
|
|
|
void
|
|
libucontext_makecontext(libucontext_ucontext_t *ucp, void (*func)(), int argc, ...)
|
|
{
|
|
libucontext_greg_t *sp;
|
|
va_list va;
|
|
int i;
|
|
unsigned int stack_args;
|
|
|
|
stack_args = argc > 8 ? argc - 8 : 0;
|
|
|
|
sp = (libucontext_greg_t *) ((uintptr_t) ucp->uc_stack.ss_sp + ucp->uc_stack.ss_size);
|
|
sp -= stack_args + 2;
|
|
sp = (libucontext_greg_t *) ((uintptr_t) sp & -16L);
|
|
|
|
ucp->uc_mcontext.gregs[REG_NIP] = (uintptr_t) func;
|
|
ucp->uc_mcontext.gregs[REG_LNK] = (uintptr_t) &libucontext_trampoline;
|
|
ucp->uc_mcontext.gregs[REG_R31] = (uintptr_t) ucp->uc_link;
|
|
ucp->uc_mcontext.gregs[REG_SP] = (uintptr_t) sp;
|
|
|
|
sp[0] = 0;
|
|
|
|
va_start(va, argc);
|
|
|
|
for (i = 0; i < argc; i++) {
|
|
if (i < 8)
|
|
ucp->uc_mcontext.gregs[i + 3] = va_arg (va, libucontext_greg_t);
|
|
else
|
|
sp[i-8 + 2] = va_arg (va, libucontext_greg_t);
|
|
}
|
|
|
|
va_end(va);
|
|
}
|
|
|
|
#ifdef EXPORT_UNPREFIXED
|
|
extern __typeof(libucontext_makecontext) makecontext __attribute__((weak, __alias__("libucontext_makecontext")));
|
|
extern __typeof(libucontext_makecontext) __makecontext __attribute__((weak, __alias__("libucontext_makecontext")));
|
|
#endif
|