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-rw-r--r--arch/powerpc/kernel/iommu.c12
1 files changed, 12 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/iommu.c b/arch/powerpc/kernel/iommu.c
index d773dd4..88e3ec6 100644
--- a/arch/powerpc/kernel/iommu.c
+++ b/arch/powerpc/kernel/iommu.c
@@ -1088,6 +1088,14 @@ int iommu_take_ownership(struct iommu_table *tbl)
memset(tbl->it_map, 0xff, sz);
iommu_clear_tces_and_put_pages(tbl, tbl->it_offset, tbl->it_size);
+ /*
+ * Disable iommu bypass, otherwise the user can DMA to all of
+ * our physical memory via the bypass window instead of just
+ * the pages that has been explicitly mapped into the iommu
+ */
+ if (tbl->set_bypass)
+ tbl->set_bypass(tbl, false);
+
return 0;
}
EXPORT_SYMBOL_GPL(iommu_take_ownership);
@@ -1102,6 +1110,10 @@ void iommu_release_ownership(struct iommu_table *tbl)
/* Restore bit#0 set by iommu_init_table() */
if (tbl->it_offset == 0)
set_bit(0, tbl->it_map);
+
+ /* The kernel owns the device now, we can restore the iommu bypass */
+ if (tbl->set_bypass)
+ tbl->set_bypass(tbl, true);
}
EXPORT_SYMBOL_GPL(iommu_release_ownership);

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