From: Jan Beulich <jbeulich@xxxxxxxx>
commit 5a264285ed1cd32e26d9de4f3c8c6855e467fd63 upstream.
In particular -ENOMEM may come back here, from set_foreign_p2m_mapping().
Don't make problems worse, the more that handling elsewhere (together
with map's status fields now indicating whether a mapping wasn't even
attempted, and hence has to be considered failed) doesn't require this
odd way of dealing with errors.
This is part of XSA-362.
Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Reviewed-by: Juergen Gross <jgross@xxxxxxxx>
Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/block/xen-blkback/blkback.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)
--- a/drivers/block/xen-blkback/blkback.c
+++ b/drivers/block/xen-blkback/blkback.c
@@ -811,10 +811,8 @@ again:
break;
}
- if (segs_to_map) {
+ if (segs_to_map)
ret = gnttab_map_refs(map, NULL, pages_to_gnt, segs_to_map);
- BUG_ON(ret);
- }
/*
* Now swizzle the MFN in our domain with the MFN from the other domain
@@ -830,7 +828,7 @@ again:
gnttab_page_cache_put(&ring->free_pages,
&pages[seg_idx]->page, 1);
pages[seg_idx]->handle = BLKBACK_INVALID_HANDLE;
- ret |= 1;
+ ret |= !ret;
goto next;
}
pages[seg_idx]->handle = map[new_map_idx].handle;
