u-boot/lib/abuf.c
Simon Glass 99aca9efe1 abuf: Correct a corner case with abuf_realloc()
If the buffer is empty and not allocated, then abuf_realloc() tries to
copy invalid data. This happens because an incorrect change to use
memdup() was added after the original code was written.

Signed-off-by: Simon Glass <sjg@chromium.org>
2022-04-06 14:01:42 -04:00

112 lines
2.2 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* Handles a buffer that can be allocated and freed
*
* Copyright 2021 Google LLC
* Written by Simon Glass <sjg@chromium.org>
*/
#include <common.h>
#include <abuf.h>
#include <malloc.h>
#include <mapmem.h>
#include <string.h>
void abuf_set(struct abuf *abuf, void *data, size_t size)
{
abuf_uninit(abuf);
abuf->data = data;
abuf->size = size;
}
void abuf_map_sysmem(struct abuf *abuf, ulong addr, size_t size)
{
abuf_set(abuf, map_sysmem(addr, size), size);
}
bool abuf_realloc(struct abuf *abuf, size_t new_size)
{
void *ptr;
if (!new_size) {
/* easy case, just need to uninit, freeing any allocation */
abuf_uninit(abuf);
return true;
} else if (abuf->alloced) {
/* currently allocated, so need to reallocate */
ptr = realloc(abuf->data, new_size);
if (!ptr)
return false;
abuf->data = ptr;
abuf->size = new_size;
return true;
} else if (new_size <= abuf->size) {
/*
* not currently alloced and new size is no larger. Just update
* it. Data is lost off the end if new_size < abuf->size
*/
abuf->size = new_size;
return true;
} else {
/* not currently allocated and new size is larger. Alloc and
* copy in data. The new space is not inited.
*/
ptr = malloc(new_size);
if (!ptr)
return false;
if (abuf->size)
memcpy(ptr, abuf->data, abuf->size);
abuf->data = ptr;
abuf->size = new_size;
abuf->alloced = true;
return true;
}
}
void *abuf_uninit_move(struct abuf *abuf, size_t *sizep)
{
void *ptr;
if (sizep)
*sizep = abuf->size;
if (!abuf->size)
return NULL;
if (abuf->alloced) {
ptr = abuf->data;
} else {
ptr = memdup(abuf->data, abuf->size);
if (!ptr)
return NULL;
}
/* Clear everything out so there is no record of the data */
abuf_init(abuf);
return ptr;
}
void abuf_init_set(struct abuf *abuf, void *data, size_t size)
{
abuf_init(abuf);
abuf_set(abuf, data, size);
}
void abuf_init_move(struct abuf *abuf, void *data, size_t size)
{
abuf_init_set(abuf, data, size);
abuf->alloced = true;
}
void abuf_uninit(struct abuf *abuf)
{
if (abuf->alloced)
free(abuf->data);
abuf_init(abuf);
}
void abuf_init(struct abuf *abuf)
{
abuf->data = NULL;
abuf->size = 0;
abuf->alloced = false;
}