79 lines
2.8 KiB
C
79 lines
2.8 KiB
C
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/****************************************************************************
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* libs/libc/stdlib/lib_reallocarray.c
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*
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* Licensed to the Apache Software Foundation (ASF) under one or more
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* contributor license agreements. See the NOTICE file distributed with
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* this work for additional information regarding copyright ownership. The
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* ASF licenses this file to you under the Apache License, Version 2.0 (the
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* "License"); you may not use this file except in compliance with the
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* License. You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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* License for the specific language governing permissions and limitations
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* under the License.
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*
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****************************************************************************/
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/****************************************************************************
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* Included Files
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****************************************************************************/
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#include <stdlib.h>
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#include <unistd.h>
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#include "libc.h"
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/****************************************************************************
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* Pre-processor definitions
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****************************************************************************/
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/* Set overflow control only if larger than 65536 for bit platforms. The
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* limit is the same as in OpenBSD.
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*/
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#define CHECK_OVERFLOW_LIMIT (1UL << (sizeof(size_t) * 4))
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/****************************************************************************
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* Public Functions
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****************************************************************************/
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/****************************************************************************
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* Name: reallocarray
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*
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* Description:
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* The reallocarray function has the same functionality as realloc but
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* it fails safely if multiplication overflow occurs.
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*
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* Input Parameters:
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* ptr - old memory to be reallocated and freed
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* nmemb - number of elements
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* size - size of one element in bytes
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*
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* Returned Value:
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* Upon successful completion, the address of the re-allocated memory
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* is returned and previous pointer is freed. NULL is returned on error
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* with original block of memory left unchanged.
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*
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****************************************************************************/
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FAR void *reallocarray(FAR void *ptr, size_t nmemb, size_t size)
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{
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if (nmemb != 0 && (nmemb >= CHECK_OVERFLOW_LIMIT ||
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size >= CHECK_OVERFLOW_LIMIT))
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{
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/* Do division only if at least one element is larget than limit */
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if ((SIZE_MAX / nmemb) < size)
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{
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set_errno(ENOMEM);
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return NULL;
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}
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}
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return lib_realloc(ptr, nmemb * size);
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}
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