swiotlb: add overflow checks to swiotlb_bounce

This is a follow-up on 5f89468e2f06 ("swiotlb: manipulate orig_addr
when tlb_addr has offset") which fixed unaligned dma mappings,
making sure the following overflows are caught:

- offset of the start of the slot within the device bigger than
requested address' offset, in other words if the base address
given in swiotlb_tbl_map_single to create the mapping (orig_addr)
was after the requested address for the sync (tlb_offset) in the
same block:

 |------------------------------------------| block
              <----------------------------> mapped part of the block
              ^
              orig_addr
       ^
       invalid tlb_addr for sync

- if the resulting offset was bigger than the allocation size
this one could happen if the mapping was not until the end. e.g.

 |------------------------------------------| block
      <---------------------> mapped part of the block
      ^                               ^
      orig_addr                       invalid tlb_addr

Both should never happen so print a warning and bail out without trying
to adjust the sizes/offsets: the first one could try to sync from
orig_addr to whatever is left of the requested size, but the later
really has nothing to sync there...

Signed-off-by: Dominique Martinet <[email protected]>
Cc: Konrad Rzeszutek Wilk <[email protected]>
Reviewed-by: Bumyong Lee <[email protected]
Cc: Chanho Park <[email protected]>
Cc: Christoph Hellwig <[email protected]>
Signed-off-by: Konrad Rzeszutek Wilk <[email protected]>

0 files changed, 0 insertions, 0 deletions