android_kernel_xiaomi_sm7250/sound/core/memalloc.c
Takashi Iwai 05243cf88f ALSA: memalloc: Align buffer allocations in page size
commit 5c1733e33c888a3cb7f576564d8ad543d5ad4a9e upstream.

Currently the standard memory allocator (snd_dma_malloc_pages*())
passes the byte size to allocate as is.  Most of the backends
allocates real pages, hence the actual allocations are aligned in page
size.  However, the genalloc doesn't seem assuring the size alignment,
hence it may result in the access outside the buffer when the whole
memory pages are exposed via mmap.

For avoiding such inconsistencies, this patch makes the allocation
size always to be aligned in page size.

Note that, after this change, snd_dma_buffer.bytes field contains the
aligned size, not the originally requested size.  This value is also
used for releasing the pages in return.

Reviewed-by: Lars-Peter Clausen <lars@metafoo.de>
Link: https://lore.kernel.org/r/20201218145625.2045-2-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-07-29 17:10:36 +02:00

292 lines
7.4 KiB
C

/*
* Copyright (c) by Jaroslav Kysela <perex@perex.cz>
* Takashi Iwai <tiwai@suse.de>
*
* Generic memory allocators
*
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*/
#include <linux/slab.h>
#include <linux/mm.h>
#include <linux/dma-mapping.h>
#include <linux/genalloc.h>
#include <sound/memalloc.h>
/*
*
* Generic memory allocators
*
*/
/**
* snd_malloc_pages - allocate pages with the given size
* @size: the size to allocate in bytes
* @gfp_flags: the allocation conditions, GFP_XXX
*
* Allocates the physically contiguous pages with the given size.
*
* Return: The pointer of the buffer, or %NULL if no enough memory.
*/
void *snd_malloc_pages(size_t size, gfp_t gfp_flags)
{
int pg;
if (WARN_ON(!size))
return NULL;
if (WARN_ON(!gfp_flags))
return NULL;
gfp_flags |= __GFP_COMP; /* compound page lets parts be mapped */
pg = get_order(size);
return (void *) __get_free_pages(gfp_flags, pg);
}
EXPORT_SYMBOL(snd_malloc_pages);
/**
* snd_free_pages - release the pages
* @ptr: the buffer pointer to release
* @size: the allocated buffer size
*
* Releases the buffer allocated via snd_malloc_pages().
*/
void snd_free_pages(void *ptr, size_t size)
{
int pg;
if (ptr == NULL)
return;
pg = get_order(size);
free_pages((unsigned long) ptr, pg);
}
EXPORT_SYMBOL(snd_free_pages);
/*
*
* Bus-specific memory allocators
*
*/
#ifdef CONFIG_HAS_DMA
/* allocate the coherent DMA pages */
static void *snd_malloc_dev_pages(struct device *dev, size_t size, dma_addr_t *dma)
{
int pg;
gfp_t gfp_flags;
if (WARN_ON(!dma))
return NULL;
pg = get_order(size);
gfp_flags = GFP_KERNEL
| __GFP_COMP /* compound page lets parts be mapped */
| __GFP_NORETRY /* don't trigger OOM-killer */
| __GFP_NOWARN; /* no stack trace print - this call is non-critical */
return dma_alloc_coherent(dev, PAGE_SIZE << pg, dma, gfp_flags);
}
/* free the coherent DMA pages */
static void snd_free_dev_pages(struct device *dev, size_t size, void *ptr,
dma_addr_t dma)
{
int pg;
if (ptr == NULL)
return;
pg = get_order(size);
dma_free_coherent(dev, PAGE_SIZE << pg, ptr, dma);
}
#ifdef CONFIG_GENERIC_ALLOCATOR
/**
* snd_malloc_dev_iram - allocate memory from on-chip internal ram
* @dmab: buffer allocation record to store the allocated data
* @size: number of bytes to allocate from the iram
*
* This function requires iram phandle provided via of_node
*/
static void snd_malloc_dev_iram(struct snd_dma_buffer *dmab, size_t size)
{
struct device *dev = dmab->dev.dev;
struct gen_pool *pool = NULL;
dmab->area = NULL;
dmab->addr = 0;
if (dev->of_node)
pool = of_gen_pool_get(dev->of_node, "iram", 0);
if (!pool)
return;
/* Assign the pool into private_data field */
dmab->private_data = pool;
dmab->area = gen_pool_dma_alloc(pool, size, &dmab->addr);
}
/**
* snd_free_dev_iram - free allocated specific memory from on-chip internal ram
* @dmab: buffer allocation record to store the allocated data
*/
static void snd_free_dev_iram(struct snd_dma_buffer *dmab)
{
struct gen_pool *pool = dmab->private_data;
if (pool && dmab->area)
gen_pool_free(pool, (unsigned long)dmab->area, dmab->bytes);
}
#endif /* CONFIG_GENERIC_ALLOCATOR */
#endif /* CONFIG_HAS_DMA */
/*
*
* ALSA generic memory management
*
*/
/**
* snd_dma_alloc_pages - allocate the buffer area according to the given type
* @type: the DMA buffer type
* @device: the device pointer
* @size: the buffer size to allocate
* @dmab: buffer allocation record to store the allocated data
*
* Calls the memory-allocator function for the corresponding
* buffer type.
*
* Return: Zero if the buffer with the given size is allocated successfully,
* otherwise a negative value on error.
*/
int snd_dma_alloc_pages(int type, struct device *device, size_t size,
struct snd_dma_buffer *dmab)
{
if (WARN_ON(!size))
return -ENXIO;
if (WARN_ON(!dmab))
return -ENXIO;
size = PAGE_ALIGN(size);
dmab->dev.type = type;
dmab->dev.dev = device;
dmab->bytes = 0;
switch (type) {
case SNDRV_DMA_TYPE_CONTINUOUS:
dmab->area = snd_malloc_pages(size,
(__force gfp_t)(unsigned long)device);
dmab->addr = 0;
break;
#ifdef CONFIG_HAS_DMA
#ifdef CONFIG_GENERIC_ALLOCATOR
case SNDRV_DMA_TYPE_DEV_IRAM:
snd_malloc_dev_iram(dmab, size);
if (dmab->area)
break;
/* Internal memory might have limited size and no enough space,
* so if we fail to malloc, try to fetch memory traditionally.
*/
dmab->dev.type = SNDRV_DMA_TYPE_DEV;
#endif /* CONFIG_GENERIC_ALLOCATOR */
case SNDRV_DMA_TYPE_DEV:
dmab->area = snd_malloc_dev_pages(device, size, &dmab->addr);
break;
#endif
#ifdef CONFIG_SND_DMA_SGBUF
case SNDRV_DMA_TYPE_DEV_SG:
snd_malloc_sgbuf_pages(device, size, dmab, NULL);
break;
#endif
default:
pr_err("snd-malloc: invalid device type %d\n", type);
dmab->area = NULL;
dmab->addr = 0;
return -ENXIO;
}
if (! dmab->area)
return -ENOMEM;
dmab->bytes = size;
return 0;
}
EXPORT_SYMBOL(snd_dma_alloc_pages);
/**
* snd_dma_alloc_pages_fallback - allocate the buffer area according to the given type with fallback
* @type: the DMA buffer type
* @device: the device pointer
* @size: the buffer size to allocate
* @dmab: buffer allocation record to store the allocated data
*
* Calls the memory-allocator function for the corresponding
* buffer type. When no space is left, this function reduces the size and
* tries to allocate again. The size actually allocated is stored in
* res_size argument.
*
* Return: Zero if the buffer with the given size is allocated successfully,
* otherwise a negative value on error.
*/
int snd_dma_alloc_pages_fallback(int type, struct device *device, size_t size,
struct snd_dma_buffer *dmab)
{
int err;
while ((err = snd_dma_alloc_pages(type, device, size, dmab)) < 0) {
if (err != -ENOMEM)
return err;
if (size <= PAGE_SIZE)
return -ENOMEM;
size >>= 1;
size = PAGE_SIZE << get_order(size);
}
if (! dmab->area)
return -ENOMEM;
return 0;
}
EXPORT_SYMBOL(snd_dma_alloc_pages_fallback);
/**
* snd_dma_free_pages - release the allocated buffer
* @dmab: the buffer allocation record to release
*
* Releases the allocated buffer via snd_dma_alloc_pages().
*/
void snd_dma_free_pages(struct snd_dma_buffer *dmab)
{
switch (dmab->dev.type) {
case SNDRV_DMA_TYPE_CONTINUOUS:
snd_free_pages(dmab->area, dmab->bytes);
break;
#ifdef CONFIG_HAS_DMA
#ifdef CONFIG_GENERIC_ALLOCATOR
case SNDRV_DMA_TYPE_DEV_IRAM:
snd_free_dev_iram(dmab);
break;
#endif /* CONFIG_GENERIC_ALLOCATOR */
case SNDRV_DMA_TYPE_DEV:
snd_free_dev_pages(dmab->dev.dev, dmab->bytes, dmab->area, dmab->addr);
break;
#endif
#ifdef CONFIG_SND_DMA_SGBUF
case SNDRV_DMA_TYPE_DEV_SG:
snd_free_sgbuf_pages(dmab);
break;
#endif
default:
pr_err("snd-malloc: invalid device type %d\n", dmab->dev.type);
}
}
EXPORT_SYMBOL(snd_dma_free_pages);