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authorJoerg Roedel <jroedel@suse.de>2014-11-04 14:53:51 +0100
committerJoerg Roedel <jroedel@suse.de>2014-11-04 14:53:51 +0100
commit38ec010d9b04ed94845f8ff6f10d33eb6bbfe180 (patch)
tree7e54787fbc0961a02707f38e5b39bfa2f22605c4 /drivers/iommu/iommu.c
parent315786ebbf4ad6552b6fd8e0e7b2ea220fcbfdbd (diff)
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>
Diffstat (limited to 'drivers/iommu/iommu.c')
-rw-r--r--drivers/iommu/iommu.c29
1 files changed, 18 insertions, 11 deletions
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 46727ce9280d..08c53c5a046f 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -1127,26 +1127,33 @@ EXPORT_SYMBOL_GPL(iommu_unmap);
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);