From 5eed69ffd248c9f68f56c710caf07db134aef28b Mon Sep 17 00:00:00 2001 From: Dwight Engen Date: Fri, 19 Sep 2014 09:42:53 -0400 Subject: [PATCH] sunvdc: limit each sg segment to a page ldc_map_sg() could fail its check that the number of pages referred to by the sg scatterlist was <= the number of cookies. This fixes the issue by doing a similar thing to the xen-blkfront driver, ensuring that the scatterlist will only ever contain a segment count <= port->ring_cookies, and each segment will be page aligned, and <= page size. This ensures that the scatterlist is always mappable. Orabug: 19347817 OraBZ: 15945 Signed-off-by: Dwight Engen Signed-off-by: David S. Miller --- drivers/block/sunvdc.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/block/sunvdc.c b/drivers/block/sunvdc.c index 1616ad091a5e..1a9360da1f54 100644 --- a/drivers/block/sunvdc.c +++ b/drivers/block/sunvdc.c @@ -747,6 +747,10 @@ static int probe_disk(struct vdc_port *port) port->disk = g; + /* Each segment in a request is up to an aligned page in size. */ + blk_queue_segment_boundary(q, PAGE_SIZE - 1); + blk_queue_max_segment_size(q, PAGE_SIZE); + blk_queue_max_segments(q, port->ring_cookies); blk_queue_max_hw_sectors(q, port->max_xfer_size); g->major = vdc_major; -- 2.20.1