1232c44718
Of course, alloca() shouldn't be used with anything that can grow without bounds anyway, but let's better safe than sorry, and catch this early. Since alloca() is not supposed to return an error we trigger an assert() instead, which is still better than heap trickery.
137 lines
4.9 KiB
C
137 lines
4.9 KiB
C
/* SPDX-License-Identifier: LGPL-2.1+ */
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#pragma once
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/***
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This file is part of systemd.
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Copyright 2010 Lennart Poettering
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***/
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#include <alloca.h>
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#include <stddef.h>
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#include <stdlib.h>
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#include <string.h>
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#include "macro.h"
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#define new(t, n) ((t*) malloc_multiply(sizeof(t), (n)))
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#define new0(t, n) ((t*) calloc((n), sizeof(t)))
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#define newa(t, n) \
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({ \
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assert(!size_multiply_overflow(sizeof(t), n)); \
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(t*) alloca(sizeof(t)*(n)); \
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})
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#define newa0(t, n) \
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({ \
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assert(!size_multiply_overflow(sizeof(t), n)); \
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(t*) alloca0(sizeof(t)*(n)); \
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})
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#define newdup(t, p, n) ((t*) memdup_multiply(p, sizeof(t), (n)))
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#define newdup_suffix0(t, p, n) ((t*) memdup_suffix0_multiply(p, sizeof(t), (n)))
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#define malloc0(n) (calloc(1, (n)))
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static inline void *mfree(void *memory) {
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free(memory);
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return NULL;
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}
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#define free_and_replace(a, b) \
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({ \
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free(a); \
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(a) = (b); \
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(b) = NULL; \
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0; \
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})
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void* memdup(const void *p, size_t l) _alloc_(2);
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void* memdup_suffix0(const void *p, size_t l) _alloc_(2);
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static inline void freep(void *p) {
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free(*(void**) p);
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}
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#define _cleanup_free_ _cleanup_(freep)
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static inline bool size_multiply_overflow(size_t size, size_t need) {
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return _unlikely_(need != 0 && size > (SIZE_MAX / need));
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}
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_malloc_ _alloc_(1, 2) static inline void *malloc_multiply(size_t size, size_t need) {
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if (size_multiply_overflow(size, need))
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return NULL;
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return malloc(size * need);
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}
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#if !HAVE_REALLOCARRAY
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_alloc_(2, 3) static inline void *reallocarray(void *p, size_t need, size_t size) {
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if (size_multiply_overflow(size, need))
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return NULL;
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return realloc(p, size * need);
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}
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#endif
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_alloc_(2, 3) static inline void *memdup_multiply(const void *p, size_t size, size_t need) {
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if (size_multiply_overflow(size, need))
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return NULL;
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return memdup(p, size * need);
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}
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_alloc_(2, 3) static inline void *memdup_suffix0_multiply(const void *p, size_t size, size_t need) {
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if (size_multiply_overflow(size, need))
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return NULL;
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return memdup_suffix0(p, size * need);
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}
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void* greedy_realloc(void **p, size_t *allocated, size_t need, size_t size);
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void* greedy_realloc0(void **p, size_t *allocated, size_t need, size_t size);
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#define GREEDY_REALLOC(array, allocated, need) \
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greedy_realloc((void**) &(array), &(allocated), (need), sizeof((array)[0]))
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#define GREEDY_REALLOC0(array, allocated, need) \
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greedy_realloc0((void**) &(array), &(allocated), (need), sizeof((array)[0]))
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#define alloca0(n) \
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({ \
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char *_new_; \
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size_t _len_ = n; \
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_new_ = alloca(_len_); \
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(void *) memset(_new_, 0, _len_); \
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})
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/* It's not clear what alignment glibc/gcc alloca() guarantee, hence provide a guaranteed safe version */
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#define alloca_align(size, align) \
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({ \
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void *_ptr_; \
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size_t _mask_ = (align) - 1; \
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_ptr_ = alloca((size) + _mask_); \
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(void*)(((uintptr_t)_ptr_ + _mask_) & ~_mask_); \
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})
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#define alloca0_align(size, align) \
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({ \
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void *_new_; \
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size_t _size_ = (size); \
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_new_ = alloca_align(_size_, (align)); \
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(void*)memset(_new_, 0, _size_); \
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})
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/* Takes inspiration from Rusts's Option::take() method: reads and returns a pointer, but at the same time resets it to
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* NULL. See: https://doc.rust-lang.org/std/option/enum.Option.html#method.take */
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#define TAKE_PTR(ptr) \
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({ \
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typeof(ptr) _ptr_ = (ptr); \
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(ptr) = NULL; \
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_ptr_; \
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})
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