path: root/drivers/xen
diff options
authorStefano Stabellini <stefano.stabellini@eu.citrix.com>2012-09-12 12:44:30 +0100
committerKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>2012-09-12 11:21:40 -0400
commit2fc136eecd0c647a6b13fcd00d0c41a1a28f35a5 (patch)
tree2a43ce841b2bedf8206609b6c43321e540540c35 /drivers/xen
parent80ba77dfbce85f2d1be54847de3c866de1b18a9a (diff)
xen/m2p: do not reuse kmap_op->dev_bus_addr
If the caller passes a valid kmap_op to m2p_add_override, we use kmap_op->dev_bus_addr to store the original mfn, but dev_bus_addr is part of the interface with Xen and if we are batching the hypercalls it might not have been written by the hypervisor yet. That means that later on Xen will write to it and we'll think that the original mfn is actually what Xen has written to it. Rather than "stealing" struct members from kmap_op, keep using page->index to store the original mfn and add another parameter to m2p_remove_override to get the corresponding kmap_op instead. It is now responsibility of the caller to keep track of which kmap_op corresponds to a particular page in the m2p_override (gntdev, the only user of this interface that passes a valid kmap_op, is already doing that). CC: stable@kernel.org Reported-and-Tested-By: Sander Eikelenboom <linux@eikelenboom.it> Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Diffstat (limited to 'drivers/xen')
2 files changed, 7 insertions, 4 deletions
diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c
index 1ffd03bf8e10..7f1241608489 100644
--- a/drivers/xen/gntdev.c
+++ b/drivers/xen/gntdev.c
@@ -314,8 +314,9 @@ static int __unmap_grant_pages(struct grant_map *map, int offset, int pages)
- err = gnttab_unmap_refs(map->unmap_ops + offset, map->pages + offset,
- pages, true);
+ err = gnttab_unmap_refs(map->unmap_ops + offset,
+ use_ptemod ? map->kmap_ops + offset : NULL, map->pages + offset,
+ pages);
if (err)
return err;
diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c
index 0bfc1ef11259..006726688baf 100644
--- a/drivers/xen/grant-table.c
+++ b/drivers/xen/grant-table.c
@@ -870,7 +870,8 @@ int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops,
int gnttab_unmap_refs(struct gnttab_unmap_grant_ref *unmap_ops,
- struct page **pages, unsigned int count, bool clear_pte)
+ struct gnttab_map_grant_ref *kmap_ops,
+ struct page **pages, unsigned int count)
int i, ret;
bool lazy = false;
@@ -888,7 +889,8 @@ int gnttab_unmap_refs(struct gnttab_unmap_grant_ref *unmap_ops,
for (i = 0; i < count; i++) {
- ret = m2p_remove_override(pages[i], clear_pte);
+ ret = m2p_remove_override(pages[i], kmap_ops ?
+ &kmap_ops[i] : NULL);
if (ret)
return ret;