From 53f131c284e83c29c227c0938926a82b2ed4d7ba Mon Sep 17 00:00:00 2001
From: Jan Beulich <jbeulich@suse.com>
Date: Tue, 23 Feb 2021 17:26:21 +0100
Subject: [PATCH] xen-front-pgdir-shbuf: don't record wrong grant handle upon
error
In order for subsequent unmapping to not mistakenly unmap handle 0,
record a perceived always-invalid one instead.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
Link: https://lore.kernel.org/r/82414b0f-1b63-5509-7c1d-5bcc8239a3de@suse.com
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
---
drivers/xen/xen-front-pgdir-shbuf.c | 11 +++++++++--
1 file changed, 9 insertions(+), 2 deletions(-)
diff --git a/drivers/xen/xen-front-pgdir-shbuf.c b/drivers/xen/xen-front-pgdir-shbuf.c
index 48a658dc7ccfc..81b6e13fa5ecb 100644
--- a/drivers/xen/xen-front-pgdir-shbuf.c
+++ b/drivers/xen/xen-front-pgdir-shbuf.c
@@ -305,11 +305,18 @@ static int backend_map(struct xen_front_pgdir_shbuf *buf)
/* Save handles even if error, so we can unmap. */
for (cur_page = 0; cur_page < buf->num_pages; cur_page++) {
- buf->backend_map_handles[cur_page] = map_ops[cur_page].handle;
- if (unlikely(map_ops[cur_page].status != GNTST_okay))
+ if (likely(map_ops[cur_page].status == GNTST_okay)) {
+ buf->backend_map_handles[cur_page] =
+ map_ops[cur_page].handle;
+ } else {
+ buf->backend_map_handles[cur_page] =
+ INVALID_GRANT_HANDLE;
+ if (!ret)
+ ret = -ENXIO;
dev_err(&buf->xb_dev->dev,
"Failed to map page %d: %d\n",
cur_page, map_ops[cur_page].status);
+ }
}
if (ret) {
--
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