nuttx-update/fs/shm/shmfs_alloc.c
Jukka Laitinen 1a74a44022 fs/shm/shmfs_alloc.c: Allocate zero-initialized memory in flat build
POSIX requires that the shm objects are zero-initialized. This has been broken
in some earlier commits (starting from 9af5fc5d09)

Also fix the flat build memory allocation to allocate both object data and payload
in the same chunk (as the comment also suggests). This saves allocations and memory
in a system with lots of shm objects.

Signed-off-by: Jukka Laitinen <jukkax@ssrc.tii.ae>
2024-12-13 18:19:38 +08:00

182 lines
4.6 KiB
C

/****************************************************************************
* fs/shm/shmfs_alloc.c
*
* SPDX-License-Identifier: Apache-2.0
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <stdbool.h>
#include <nuttx/arch.h>
#include <nuttx/cache.h>
#include <nuttx/nuttx.h>
#include <nuttx/kmalloc.h>
#include <nuttx/pgalloc.h>
#include "shm/shmfs.h"
#include "fs_heap.h"
/****************************************************************************
* Public Functions
****************************************************************************/
FAR struct shmfs_object_s *shmfs_alloc_object(size_t length)
{
FAR struct shmfs_object_s *object;
bool allocated = false;
#if defined(CONFIG_BUILD_FLAT)
/* in FLAT build, allocate the object metadata and the data in the same
* chunk in kernel heap
*/
size_t hdr_size = sizeof(struct shmfs_object_s);
size_t alloc_size = length;
size_t cachesize = up_get_dcache_linesize();
if (cachesize > 0)
{
hdr_size = ALIGN_UP(hdr_size, cachesize);
alloc_size = ALIGN_UP(alloc_size, cachesize);
object = fs_heap_memalign(cachesize, hdr_size + alloc_size);
}
else
{
object = fs_heap_malloc(hdr_size + alloc_size);
}
if (object)
{
memset(object, 0, hdr_size + alloc_size);
object->paddr = (void *)((uintptr_t)object + hdr_size);
allocated = true;
}
#elif defined(CONFIG_BUILD_PROTECTED)
/* in PROTECTED build, allocate the shm object in kernel heap, and shared
* memory in user heap
*/
size_t alloc_size = length;
object = fs_heap_zalloc(sizeof(struct shmfs_object_s));
if (object)
{
size_t cachesize = up_get_dcache_linesize();
if (cachesize > 0)
{
alloc_size = ALIGN_UP(alloc_size, cachesize);
object->paddr = kumm_memalign(cachesize, alloc_size);
}
else
{
object->paddr = kumm_malloc(alloc_size);
}
if (object->paddr)
{
memset(object->paddr, 0, alloc_size);
allocated = true;
}
}
#elif defined(CONFIG_BUILD_KERNEL)
/* in KERNEL build, allocate the shared memory from page pool and store the
* physical address
*/
size_t i = 0;
FAR void **pages;
size_t n_pages = MM_NPAGES(length);
object = fs_heap_zalloc(sizeof(struct shmfs_object_s) +
(n_pages - 1) * sizeof(object->paddr));
if (object)
{
pages = &object->paddr;
for (; i < n_pages; i++)
{
pages[i] = (FAR void *)mm_pgalloc(1);
if (!pages[i])
{
break;
}
else
{
/* Clear the page memory (requirement for truncate) */
up_addrenv_page_wipe((uintptr_t)pages[i]);
}
}
}
if (i == n_pages)
{
allocated = true;
}
#endif
if (allocated)
{
object->length = length;
}
else
{
/* delete any partial allocation */
shmfs_free_object(object);
object = NULL;
}
return object;
}
void shmfs_free_object(FAR struct shmfs_object_s *object)
{
if (object)
{
#if defined(CONFIG_BUILD_PROTECTED)
kumm_free(object->paddr);
#elif defined(CONFIG_BUILD_KERNEL)
size_t i;
size_t n_pages = MM_NPAGES(object->length);
FAR void **pages = &object->paddr;
for (i = 0; i < n_pages; i++)
{
if (pages[i])
{
mm_pgfree((uintptr_t)pages[i], 1);
}
}
#endif
/* Delete the object metadata
* (and the shared memory in case of FLAT build)
*/
fs_heap_free(object);
}
}