/* * Copyright (c) 2018 Ariadne Conill * * 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. */ #define _GNU_SOURCE #include #include #include #include #include #include #include "defs.h" extern void __start_context(void); void __makecontext(ucontext_t *ucp, void (*func)(void), int argc, ...) { unsigned long *sp; unsigned long *regp; va_list va; int i; sp = (unsigned long *) ((uintptr_t) ucp->uc_stack.ss_sp + ucp->uc_stack.ss_size); sp -= argc < 8 ? 0 : argc - 8; sp = (unsigned long *) (((uintptr_t) sp & -16L)); ucp->uc_mcontext.sp = (uintptr_t) sp; ucp->uc_mcontext.pc = (uintptr_t) func; ucp->uc_mcontext.regs[19] = (uintptr_t) ucp->uc_link; ucp->uc_mcontext.regs[30] = (uintptr_t) &__start_context; va_start(va, argc); regp = &(ucp->uc_mcontext.regs[0]); for (i = 0; (i < argc && i < 8); i++) *regp++ = va_arg (va, unsigned long); for (; i < argc; i++) *sp++ = va_arg (va, unsigned long); va_end(va); } extern __typeof(__makecontext) makecontext __attribute__((weak, __alias__("__makecontext")));