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dma-direct: add dma address sanity checks 

Roughly based on the x86 pci-nommu implementation.

Signed-off-by: Christoph Hellwig <hch@lst.de>
This commit is contained in:
Christoph Hellwig 2018-01-09 16:30:47 +01:00
parent 2e86a04780
commit 2797596992
1 changed files with 30 additions and 1 deletions
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31
lib/dma-direct.c
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@ -9,6 +9,23 @@
#include <linux/scatterlist.h>
#include <linux/pfn.h>
#define DIRECT_MAPPING_ERROR 0
static bool
check_addr(struct device *dev, dma_addr_t dma_addr, size_t size,
const char *caller)
{
if (unlikely(dev && !dma_capable(dev, dma_addr, size))) {
if (*dev->dma_mask >= DMA_BIT_MASK(32)) {
dev_err(dev,
"%s: overflow %pad+%zu of device mask %llx\n",
caller, &dma_addr, size, *dev->dma_mask);
}
return false;
}
return true;
}
static void *dma_direct_alloc(struct device *dev, size_t size,
dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs)
{
@ -31,7 +48,11 @@ static dma_addr_t dma_direct_map_page(struct device *dev, struct page *page,
unsigned long offset, size_t size, enum dma_data_direction dir,
unsigned long attrs)
{
return phys_to_dma(dev, page_to_phys(page)) + offset;
dma_addr_t dma_addr = phys_to_dma(dev, page_to_phys(page)) + offset;
if (!check_addr(dev, dma_addr, size, __func__))
return DIRECT_MAPPING_ERROR;
return dma_addr;
}
static int dma_direct_map_sg(struct device *dev, struct scatterlist *sgl,
@ -44,16 +65,24 @@ static int dma_direct_map_sg(struct device *dev, struct scatterlist *sgl,
BUG_ON(!sg_page(sg));
sg_dma_address(sg) = phys_to_dma(dev, sg_phys(sg));
if (!check_addr(dev, sg_dma_address(sg), sg->length, __func__))
return 0;
sg_dma_len(sg) = sg->length;
}
return nents;
}
static int dma_direct_mapping_error(struct device *dev, dma_addr_t dma_addr)
{
return dma_addr == DIRECT_MAPPING_ERROR;
}
const struct dma_map_ops dma_direct_ops = {
.alloc = dma_direct_alloc,
.free = dma_direct_free,
.map_page = dma_direct_map_page,
.map_sg = dma_direct_map_sg,
.mapping_error = dma_direct_mapping_error,
};
EXPORT_SYMBOL(dma_direct_ops);