2020-02-07 14:28:30

by Sergey Dyasli

Subject: [PATCH v3 3/4] xen: teach KASAN about grant tables

From: Ross Lagerwall <[email protected]>

Otherwise it produces lots of false positives when a guest starts using
PV I/O devices.

Signed-off-by: Ross Lagerwall <[email protected]>
Signed-off-by: Sergey Dyasli <[email protected]>
---
v2 --> v3: no changes

v1 --> v2: no changes

RFC --> v1:
- Slightly clarified the commit message
---
drivers/xen/grant-table.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c
index 7b36b51cdb9f..ce95f7232de6 100644
--- a/drivers/xen/grant-table.c
+++ b/drivers/xen/grant-table.c
@@ -1048,6 +1048,7 @@ int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops,
foreign = xen_page_foreign(pages[i]);
foreign->domid = map_ops[i].dom;
foreign->gref = map_ops[i].ref;
+ kasan_alloc_pages(pages[i], 0);
break;
}

@@ -1084,8 +1085,10 @@ int gnttab_unmap_refs(struct gnttab_unmap_grant_ref *unmap_ops,
if (ret)
return ret;

- for (i = 0; i < count; i++)
+ for (i = 0; i < count; i++) {
ClearPageForeign(pages[i]);
+ kasan_free_pages(pages[i], 0);
+ }

return clear_foreign_p2m_mapping(unmap_ops, kunmap_ops, pages, count);
}
--
2.17.1

2020-02-10 20:34:06

by Boris Ostrovsky

Subject: Re: [PATCH v3 3/4] xen: teach KASAN about grant tables

On 2/7/20 9:26 AM, Sergey Dyasli wrote:
> From: Ross Lagerwall <[email protected]>
>
> Otherwise it produces lots of false positives when a guest starts using
> PV I/O devices.
>
> Signed-off-by: Ross Lagerwall <[email protected]>
> Signed-off-by: Sergey Dyasli <[email protected]>
>


Reviewed-by: Boris Ostrovsky <[email protected]>