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| author | Stefano Stabellini <stefano.stabellini@eu.citrix.com> | 2012-09-12 12:44:30 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-10-02 10:30:06 -0700 |
| commit | 449efd1d33fcf40a81f902ceed6a21a406f8d105 (patch) | |
| tree | 2369eb51e11ae3f8ce450055593a6649e7675980 /drivers/xen | |
| parent | 967c0e4ab954d228ca87d85c523ae8a65c03cc5e (diff) | |
| download | linux-3.10-449efd1d33fcf40a81f902ceed6a21a406f8d105.tar.gz linux-3.10-449efd1d33fcf40a81f902ceed6a21a406f8d105.tar.bz2 linux-3.10-449efd1d33fcf40a81f902ceed6a21a406f8d105.zip | |
xen/m2p: do not reuse kmap_op->dev_bus_addr
commit 2fc136eecd0c647a6b13fcd00d0c41a1a28f35a5 upstream.
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).
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/xen')
| -rw-r--r-- | drivers/xen/gntdev.c | 5 | ||||
| -rw-r--r-- | drivers/xen/grant-table.c | 6 |
2 files changed, 7 insertions, 4 deletions
diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c index 1ffd03bf8e1..7f124160848 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 f100ce20b16..fda491cd53c 100644 --- a/drivers/xen/grant-table.c +++ b/drivers/xen/grant-table.c @@ -774,7 +774,8 @@ int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops, EXPORT_SYMBOL_GPL(gnttab_map_refs); 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; @@ -786,7 +787,8 @@ int gnttab_unmap_refs(struct gnttab_unmap_grant_ref *unmap_ops, return ret; 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; } |