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/* SPDX-License-Identifier: LGPL-2.1-or-later */
#include <malloc.h>
#include <stdint.h>
#include <string.h>
#include "alloc-util.h"
#include "macro.h"
#include "memory-util.h"
void* memdup(const void *p, size_t l) {
void *ret;
assert(l == 0 || p);
ret = malloc(l ?: 1);
if (!ret)
return NULL;
return memcpy_safe(ret, p, l);
}
void* memdup_suffix0(const void *p, size_t l) {
void *ret;
assert(l == 0 || p);
/* The same as memdup() but place a safety NUL byte after the allocated memory */
if (_unlikely_(l == SIZE_MAX)) /* prevent overflow */
return NULL;
ret = malloc(l + 1);
if (!ret)
return NULL;
((uint8_t*) ret)[l] = 0;
return memcpy_safe(ret, p, l);
}
void* greedy_realloc(
void **p,
size_t need,
size_t size) {
size_t a, newalloc;
void *q;
assert(p);
/* We use malloc_usable_size() for determining the current allocated size. On all systems we care
* about this should be safe to rely on. Should there ever arise the need to avoid relying on this we
* can instead locally fall back to realloc() on every call, rounded up to the next exponent of 2 or
* so. */
if (*p && (size == 0 || (MALLOC_SIZEOF_SAFE(*p) / size >= need)))
return *p;
if (_unlikely_(need > SIZE_MAX/2)) /* Overflow check */
return NULL;
newalloc = need * 2;
if (size_multiply_overflow(newalloc, size))
return NULL;
a = newalloc * size;
if (a < 64) /* Allocate at least 64 bytes */
a = 64;
q = realloc(*p, a);
if (!q)
return NULL;
return *p = q;
}
void* greedy_realloc0(
void **p,
size_t need,
size_t size) {
size_t before, after;
uint8_t *q;
assert(p);
before = MALLOC_SIZEOF_SAFE(*p); /* malloc_usable_size() will return 0 on NULL input, as per docs */
q = greedy_realloc(p, need, size);
if (!q)
return NULL;
after = MALLOC_SIZEOF_SAFE(q);
if (size == 0) /* avoid division by zero */
before = 0;
else
before = (before / size) * size; /* Round down */
if (after > before)
memzero(q + before, after - before);
return q;
}
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