| /* Array allocation from a fixed-size buffer. |
| Copyright (C) 2017-2018 Free Software Foundation, Inc. |
| This file is part of the GNU C Library. |
| |
| The GNU C Library is free software; you can redistribute it and/or |
| modify it under the terms of the GNU Lesser General Public |
| License as published by the Free Software Foundation; either |
| version 2.1 of the License, or (at your option) any later version. |
| |
| The GNU C Library is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| Lesser General Public License for more details. |
| |
| You should have received a copy of the GNU Lesser General Public |
| License along with the GNU C Library; if not, see |
| <http://www.gnu.org/licenses/>. */ |
| |
| #include <alloc_buffer.h> |
| #include <malloc-internal.h> |
| #include <libc-pointer-arith.h> |
| |
| void * |
| __libc_alloc_buffer_alloc_array (struct alloc_buffer *buf, size_t element_size, |
| size_t align, size_t count) |
| { |
| size_t current = buf->__alloc_buffer_current; |
| /* The caller asserts that align is a power of two. */ |
| size_t aligned = ALIGN_UP (current, align); |
| size_t size; |
| bool overflow = check_mul_overflow_size_t (element_size, count, &size); |
| size_t new_current = aligned + size; |
| if (!overflow /* Multiplication did not overflow. */ |
| && aligned >= current /* No overflow in align step. */ |
| && new_current >= size /* No overflow in size computation. */ |
| && new_current <= buf->__alloc_buffer_end) /* Room in buffer. */ |
| { |
| buf->__alloc_buffer_current = new_current; |
| return (void *) aligned; |
| } |
| else |
| { |
| alloc_buffer_mark_failed (buf); |
| return NULL; |
| } |
| } |
| libc_hidden_def (__libc_alloc_buffer_alloc_array) |