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eefed0e0cd
some standard c libraries (e.g. newlib before 4.0.0) don't perform proper overflow check in the multiplication. We just implement calloc here ourselves on top of malloc with proper overflow check in place. This might even safe a handful of ROM bytes.
74 lines
1.5 KiB
C
74 lines
1.5 KiB
C
/*
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* Copyright (C) 2019 Gunar Schorcht
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*
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* This file is subject to the terms and conditions of the GNU Lesser
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* General Public License v2.1. See the file LICENSE in the top level
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* directory for more details.
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*/
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/**
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* @{
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*
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* @file
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* @brief Implements various POSIX syscalls
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* @author Gunar Schorcht <gunar@schorcht.net>
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*/
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#include <string.h>
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#include "assert.h"
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#include "irq.h"
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#include "mutex.h"
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extern void *__real_malloc(size_t size);
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extern void __real_free(void *ptr);
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extern void *__real_realloc(void *ptr, size_t size);
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static mutex_t _lock;
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void *__wrap_malloc(size_t size)
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{
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assert(!irq_is_in());
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mutex_lock(&_lock);
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void *ptr = __real_malloc(size);
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mutex_unlock(&_lock);
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return ptr;
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}
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void __wrap_free(void *ptr)
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{
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assert(!irq_is_in());
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mutex_lock(&_lock);
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__real_free(ptr);
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mutex_unlock(&_lock);
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}
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void *__wrap_calloc(size_t nmemb, size_t size)
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{
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/* some c libs don't perform proper overflow check (e.g. newlib < 4.0.0). Hence, we
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* just implement calloc on top of malloc ourselves. In addition to ensuring proper
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* overflow checks, this likely saves a bit of ROM */
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size_t total_size;
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if (__builtin_mul_overflow(nmemb, size, &total_size)) {
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return NULL;
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}
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void *res = __wrap_malloc(total_size);
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if (res) {
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memset(res, 0, total_size);
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}
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return res;
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}
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void *__wrap_realloc(void *ptr, size_t size)
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{
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assert(!irq_is_in());
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mutex_lock(&_lock);
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void *new = __real_realloc(ptr, size);
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mutex_unlock(&_lock);
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return new;
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}
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/** @} */
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