iommu: Do more input validation in iommu_map_sg()
The IOMMU-API works on page boundarys, unlike the DMA-API
which can work with sub-page buffers. The sg->offset
field does not make sense on the IOMMU level, so force it to
be 0. Do some error-path consolidation while at it.
Signed-off-by: Joerg Roedel <jroedel@suse.de>
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 46727ce..08c53c5 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -1127,26 +1127,33 @@
size_t default_iommu_map_sg(struct iommu_domain *domain, unsigned long iova,
struct scatterlist *sg, unsigned int nents, int prot)
{
- int ret;
+ struct scatterlist *s;
size_t mapped = 0;
unsigned int i;
- struct scatterlist *s;
+ int ret;
for_each_sg(sg, s, nents, i) {
phys_addr_t phys = page_to_phys(sg_page(s));
- size_t page_len = s->offset + s->length;
- ret = iommu_map(domain, iova + mapped, phys, page_len, prot);
- if (ret) {
- /* undo mappings already done */
- iommu_unmap(domain, iova, mapped);
- mapped = 0;
- break;
- }
- mapped += page_len;
+ /* We are mapping on page boundarys, so offset must be 0 */
+ if (s->offset)
+ goto out_err;
+
+ ret = iommu_map(domain, iova + mapped, phys, s->length, prot);
+ if (ret)
+ goto out_err;
+
+ mapped += s->length;
}
return mapped;
+
+out_err:
+ /* undo mappings already done */
+ iommu_unmap(domain, iova, mapped);
+
+ return 0;
+
}
EXPORT_SYMBOL_GPL(default_iommu_map_sg);