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/* SPDX-License-Identifier: LGPL-2.1-or-later */
#pragma once
#include <alloca.h>
#include <stddef.h>
#include <stdlib.h>
#include <string.h>
#include "macro.h"
#if HAS_FEATURE_MEMORY_SANITIZER
# include <sanitizer/msan_interface.h>
#endif
typedef void (*free_func_t)(void *p);
/* If for some reason more than 4M are allocated on the stack, let's abort immediately. It's better than
* proceeding and smashing the stack limits. Note that by default RLIMIT_STACK is 8M on Linux. */
#define ALLOCA_MAX (4U*1024U*1024U)
#define new(t, n) ((t*) malloc_multiply(sizeof(t), (n)))
#define new0(t, n) ((t*) calloc((n) ?: 1, sizeof(t)))
#define newa(t, n) \
({ \
size_t _n_ = n; \
assert(!size_multiply_overflow(sizeof(t), _n_)); \
assert(sizeof(t)*_n_ <= ALLOCA_MAX); \
(t*) alloca((sizeof(t)*_n_) ?: 1); \
})
#define newa0(t, n) \
({ \
size_t _n_ = n; \
assert(!size_multiply_overflow(sizeof(t), _n_)); \
assert(sizeof(t)*_n_ <= ALLOCA_MAX); \
(t*) alloca0((sizeof(t)*_n_) ?: 1); \
})
#define newdup(t, p, n) ((t*) memdup_multiply(p, sizeof(t), (n)))
#define newdup_suffix0(t, p, n) ((t*) memdup_suffix0_multiply(p, sizeof(t), (n)))
#define malloc0(n) (calloc(1, (n) ?: 1))
static inline void *mfree(void *memory) {
free(memory);
return NULL;
}
#define free_and_replace(a, b) \
({ \
free(a); \
(a) = (b); \
(b) = NULL; \
0; \
})
void* memdup(const void *p, size_t l) _alloc_(2);
void* memdup_suffix0(const void *p, size_t l); /* We can't use _alloc_() here, since we return a buffer one byte larger than the specified size */
#define memdupa(p, l) \
({ \
void *_q_; \
size_t _l_ = l; \
assert(_l_ <= ALLOCA_MAX); \
_q_ = alloca(_l_ ?: 1); \
memcpy(_q_, p, _l_); \
})
#define memdupa_suffix0(p, l) \
({ \
void *_q_; \
size_t _l_ = l; \
assert(_l_ <= ALLOCA_MAX); \
_q_ = alloca(_l_ + 1); \
((uint8_t*) _q_)[_l_] = 0; \
memcpy(_q_, p, _l_); \
})
static inline void freep(void *p) {
*(void**)p = mfree(*(void**) p);
}
#define _cleanup_free_ _cleanup_(freep)
static inline bool size_multiply_overflow(size_t size, size_t need) {
return _unlikely_(need != 0 && size > (SIZE_MAX / need));
}
_malloc_ _alloc_(1, 2) static inline void *malloc_multiply(size_t size, size_t need) {
if (size_multiply_overflow(size, need))
return NULL;
return malloc(size * need ?: 1);
}
#if !HAVE_REALLOCARRAY
_alloc_(2, 3) static inline void *reallocarray(void *p, size_t need, size_t size) {
if (size_multiply_overflow(size, need))
return NULL;
return realloc(p, size * need ?: 1);
}
#endif
_alloc_(2, 3) static inline void *memdup_multiply(const void *p, size_t size, size_t need) {
if (size_multiply_overflow(size, need))
return NULL;
return memdup(p, size * need);
}
/* Note that we can't decorate this function with _alloc_() since the returned memory area is one byte larger
* than the product of its parameters. */
static inline void *memdup_suffix0_multiply(const void *p, size_t size, size_t need) {
if (size_multiply_overflow(size, need))
return NULL;
return memdup_suffix0(p, size * need);
}
void* greedy_realloc(void **p, size_t *allocated, size_t need, size_t size);
void* greedy_realloc0(void **p, size_t *allocated, size_t need, size_t size);
#define GREEDY_REALLOC(array, allocated, need) \
greedy_realloc((void**) &(array), &(allocated), (need), sizeof((array)[0]))
#define GREEDY_REALLOC0(array, allocated, need) \
greedy_realloc0((void**) &(array), &(allocated), (need), sizeof((array)[0]))
#define alloca0(n) \
({ \
char *_new_; \
size_t _len_ = n; \
assert(_len_ <= ALLOCA_MAX); \
_new_ = alloca(_len_ ?: 1); \
(void *) memset(_new_, 0, _len_); \
})
/* It's not clear what alignment glibc/gcc alloca() guarantee, hence provide a guaranteed safe version */
#define alloca_align(size, align) \
({ \
void *_ptr_; \
size_t _mask_ = (align) - 1; \
size_t _size_ = size; \
assert(_size_ <= ALLOCA_MAX); \
_ptr_ = alloca((_size_ + _mask_) ?: 1); \
(void*)(((uintptr_t)_ptr_ + _mask_) & ~_mask_); \
})
#define alloca0_align(size, align) \
({ \
void *_new_; \
size_t _xsize_ = (size); \
_new_ = alloca_align(_xsize_, (align)); \
(void*)memset(_new_, 0, _xsize_); \
})
#if HAS_FEATURE_MEMORY_SANITIZER
# define msan_unpoison(r, s) __msan_unpoison(r, s)
#else
# define msan_unpoison(r, s)
#endif
/* This returns the number of usable bytes in a malloc()ed region as per malloc_usable_size(), in a way that
* is compatible with _FORTIFY_SOURCES. If _FORTIFY_SOURCES is used many memory operations will take the
* object size as returned by __builtin_object_size() into account. Hence, let's return the smaller size of
* malloc_usable_size() and __builtin_object_size() here, so that we definitely operate in safe territory by
* both the compiler's and libc's standards. Note that __builtin_object_size() evaluates to SIZE_MAX if the
* size cannot be determined, hence the MIN() expression should be safe with dynamically sized memory,
* too. Moreover, when NULL is passed malloc_usable_size() is documented to return zero, and
* __builtin_object_size() returns SIZE_MAX too, hence we also return a sensible value of 0 in this corner
* case. */
#define MALLOC_SIZEOF_SAFE(x) \
MIN(malloc_usable_size(x), __builtin_object_size(x, 0))
/* Inspired by ELEMENTSOF() but operates on malloc()'ed memory areas: typesafely returns the number of items
* that fit into the specified memory block */
#define MALLOC_ELEMENTSOF(x) \
(__builtin_choose_expr( \
__builtin_types_compatible_p(typeof(x), typeof(&*(x))), \
MALLOC_SIZEOF_SAFE(x)/sizeof((x)[0]), \
VOID_0))
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