/* * Copyright (C) 2008 The Android Open Source Project * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * 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 COPYRIGHT HOLDERS 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 * COPYRIGHT OWNER 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 #include #if defined(__LP64__) static void* __bionic_brk; #else void* __bionic_brk; // Accidentally exported by the NDK. #endif extern "C" void* __brk(void* __addr); int brk(void* end_data) { __bionic_brk = __brk(end_data); if (__bionic_brk < end_data) { errno = ENOMEM; return -1; } return 0; } void* sbrk(ptrdiff_t increment) { // Initialize __bionic_brk if necessary. if (__bionic_brk == NULL) { __bionic_brk = __brk(NULL); } // Don't ask the kernel if we already know the answer. if (increment == 0) { return __bionic_brk; } // Avoid overflow. uintptr_t old_brk = reinterpret_cast(__bionic_brk); if ((increment > 0 && static_cast(increment) > (UINTPTR_MAX - old_brk)) || (increment < 0 && static_cast(-increment) > old_brk)) { errno = ENOMEM; return reinterpret_cast(-1); } void* desired_brk = reinterpret_cast(old_brk + increment); __bionic_brk = __brk(desired_brk); if (__bionic_brk < desired_brk) { errno = ENOMEM; return reinterpret_cast(-1); } return reinterpret_cast(old_brk); }