/*- * SPDX-License-Identifier: BSD-2-Clause-FreeBSD * * Copyright (c) 2018 Mark Johnston * * 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 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 AUTHOR 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 __FBSDID("$FreeBSD$"); #include #include #include #include #include void *__sys_break(char *nsize); static uintptr_t curbrk, minbrk; static int curbrk_initted; static int initbrk(void) { void *newbrk; if (!curbrk_initted) { newbrk = __sys_break(NULL); if (newbrk == (void *)-1) return (-1); curbrk = minbrk = (uintptr_t)newbrk; curbrk_initted = 1; } return (0); } static void * mvbrk(void *addr) { uintptr_t oldbrk; if ((uintptr_t)addr < minbrk) { /* Emulate legacy error handling in the syscall. */ errno = EINVAL; return ((void *)-1); } if (__sys_break(addr) == (void *)-1) return ((void *)-1); oldbrk = curbrk; curbrk = (uintptr_t)addr; return ((void *)oldbrk); } int brk(const void *addr) { if (initbrk() == -1) return (-1); if ((uintptr_t)addr < minbrk) addr = (void *)minbrk; return (mvbrk(__DECONST(void *, addr)) == (void *)-1 ? -1 : 0); } int _brk(const void *addr) { if (initbrk() == -1) return (-1); return (mvbrk(__DECONST(void *, addr)) == (void *)-1 ? -1 : 0); } void * sbrk(intptr_t incr) { if (initbrk() == -1) return ((void *)-1); if ((incr > 0 && curbrk + incr < curbrk) || (incr < 0 && curbrk + incr > curbrk)) { /* Emulate legacy error handling in the syscall. */ errno = EINVAL; return ((void *)-1); } return (mvbrk((void *)(curbrk + incr))); }