When popping a pfn from an rcache, we are currently checking it directly
against limit_pfn for viability. Since this represents iova->pfn_lo, it
is technically possible for the corresponding iova->pfn_hi to be greater
than limit_pfn. Although we generally get away with it in practice since
limit_pfn is typically a power-of-two boundary and the IOVAs are
size-aligned, it's pretty trivial to make the iova_rcache_get() path
take the allocation size into account for complete safety.
Signed-off-by: Robin Murphy <robin.mur...@arm.com>
---
drivers/iommu/iova.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/iommu/iova.c b/drivers/iommu/iova.c
index 35dde0fc7793..8f8b436afd81 100644
--- a/drivers/iommu/iova.c
+++ b/drivers/iommu/iova.c
@@ -411,7 +411,7 @@ alloc_iova_fast(struct iova_domain *iovad, unsigned long
size,
unsigned long iova_pfn;
struct iova *new_iova;
- iova_pfn = iova_rcache_get(iovad, size, limit_pfn);
+ iova_pfn = iova_rcache_get(iovad, size, limit_pfn + 1);
if (iova_pfn)
return iova_pfn;
@@ -828,7 +828,7 @@ static unsigned long iova_magazine_pop(struct iova_magazine
*mag,
{
BUG_ON(iova_magazine_empty(mag));
- if (mag->pfns[mag->size - 1] >= limit_pfn)
+ if (mag->pfns[mag->size - 1] > limit_pfn)
return 0;
return mag->pfns[--mag->size];
@@ -982,7 +982,7 @@ static unsigned long iova_rcache_get(struct iova_domain
*iovad,
if (log_size >= IOVA_RANGE_CACHE_MAX_SIZE)
return 0;
- return __iova_rcache_get(&iovad->rcaches[log_size], limit_pfn);
+ return __iova_rcache_get(&iovad->rcaches[log_size], limit_pfn - size);
}
/*
--
2.13.4.dirty
_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu
