iommu/omap: Fix buffer overflow in debugfs

There are two issues here:

1) The "len" variable needs to be checked before the very first write.
   Otherwise if omap2_iommu_dump_ctx() with "bytes" less than 32 it is a
   buffer overflow.
2) The snprintf() function returns the number of bytes that *would* have
   been copied if there were enough space.  But we want to know the
   number of bytes which were *actually* copied so use scnprintf()
   instead.

Fixes: bd4396f09a4a ("iommu/omap: Consolidate OMAP IOMMU modules")
Signed-off-by: Dan Carpenter <[email protected]>
Reviewed-by: Robin Murphy <[email protected]>
Reviewed-by: Laurent Pinchart <[email protected]>
Link: https://lore.kernel.org/r/YuvYh1JbE3v+abd5@kili
Signed-off-by: Joerg Roedel <[email protected]>

0 files changed, 0 insertions, 0 deletions