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authorJan Beulich <JBeulich@suse.com>2018-09-25 02:13:37 -0600
committerDavid S. Miller <davem@davemloft.net>2018-09-25 10:39:34 -0700
commit871088bf92e11efb69bbdbd537e48c0ad4f63729 (patch)
treed11b87a3087bb42159cecc05a7c8fbbd3ab3219a /drivers/net/xen-netback
parent22f9cde3401077ea450b69bf9b0bba373e12e454 (diff)
downloadlinux-871088bf92e11efb69bbdbd537e48c0ad4f63729.tar.bz2
xen-netback: handle page straddling in xenvif_set_hash_mapping()
There's no guarantee that the mapping array doesn't cross a page boundary. Use a second grant copy operation if necessary. Signed-off-by: Jan Beulich <jbeulich@suse.com> Acked-by: Wei Liu <wei.liu2@citrix.com> Reviewed-by: Paul Durrant <paul.durrant@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/xen-netback')
-rw-r--r--drivers/net/xen-netback/hash.c25
1 files changed, 18 insertions, 7 deletions
diff --git a/drivers/net/xen-netback/hash.c b/drivers/net/xen-netback/hash.c
index dc9841ea2fff..0ccb021f1e78 100644
--- a/drivers/net/xen-netback/hash.c
+++ b/drivers/net/xen-netback/hash.c
@@ -334,28 +334,39 @@ u32 xenvif_set_hash_mapping(struct xenvif *vif, u32 gref, u32 len,
u32 off)
{
u32 *mapping = vif->hash.mapping[!vif->hash.mapping_sel];
- struct gnttab_copy copy_op = {
+ unsigned int nr = 1;
+ struct gnttab_copy copy_op[2] = {{
.source.u.ref = gref,
.source.domid = vif->domid,
.dest.domid = DOMID_SELF,
.len = len * sizeof(*mapping),
.flags = GNTCOPY_source_gref
- };
+ }};
if ((off + len < off) || (off + len > vif->hash.size) ||
len > XEN_PAGE_SIZE / sizeof(*mapping))
return XEN_NETIF_CTRL_STATUS_INVALID_PARAMETER;
- copy_op.dest.u.gmfn = virt_to_gfn(mapping + off);
- copy_op.dest.offset = xen_offset_in_page(mapping + off);
+ copy_op[0].dest.u.gmfn = virt_to_gfn(mapping + off);
+ copy_op[0].dest.offset = xen_offset_in_page(mapping + off);
+ if (copy_op[0].dest.offset + copy_op[0].len > XEN_PAGE_SIZE) {
+ copy_op[1] = copy_op[0];
+ copy_op[1].source.offset = XEN_PAGE_SIZE - copy_op[0].dest.offset;
+ copy_op[1].dest.u.gmfn = virt_to_gfn(mapping + off + len);
+ copy_op[1].dest.offset = 0;
+ copy_op[1].len = copy_op[0].len - copy_op[1].source.offset;
+ copy_op[0].len = copy_op[1].source.offset;
+ nr = 2;
+ }
memcpy(mapping, vif->hash.mapping[vif->hash.mapping_sel],
vif->hash.size * sizeof(*mapping));
- if (copy_op.len != 0) {
- gnttab_batch_copy(&copy_op, 1);
+ if (copy_op[0].len != 0) {
+ gnttab_batch_copy(copy_op, nr);
- if (copy_op.status != GNTST_okay)
+ if (copy_op[0].status != GNTST_okay ||
+ copy_op[nr - 1].status != GNTST_okay)
return XEN_NETIF_CTRL_STATUS_INVALID_PARAMETER;
}