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authorDemi Marie Obenour <demi@invisiblethingslab.com>2022-07-11 01:05:22 +0200
committerJuergen Gross <jgross@suse.com>2022-07-11 11:39:45 +0200
commit166d3863231667c4f64dee72b77d1102cdfad11f (patch)
tree2ffdcc5ef15b616ef1f9f160d3da75e061bb0cc7 /drivers/xen/gntdev.c
parentxen/gntdev: Avoid blocking in unmap_grant_pages() (diff)
downloadlinux-166d3863231667c4f64dee72b77d1102cdfad11f.tar.xz
linux-166d3863231667c4f64dee72b77d1102cdfad11f.zip
xen/gntdev: Ignore failure to unmap INVALID_GRANT_HANDLE
The error paths of gntdev_mmap() can call unmap_grant_pages() even though not all of the pages have been successfully mapped. This will trigger the WARN_ON()s in __unmap_grant_pages_done(). The number of warnings can be very large; I have observed thousands of lines of warnings in the systemd journal. Avoid this problem by only warning on unmapping failure if the handle being unmapped is not INVALID_GRANT_HANDLE. The handle field of any page that was not successfully mapped will be INVALID_GRANT_HANDLE, so this catches all cases where unmapping can legitimately fail. Fixes: dbe97cff7dd9 ("xen/gntdev: Avoid blocking in unmap_grant_pages()") Cc: stable@vger.kernel.org Suggested-by: Juergen Gross <jgross@suse.com> Signed-off-by: Demi Marie Obenour <demi@invisiblethingslab.com> Reviewed-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> Reviewed-by: Juergen Gross <jgross@suse.com> Link: https://lore.kernel.org/r/20220710230522.1563-1-demi@invisiblethingslab.com Signed-off-by: Juergen Gross <jgross@suse.com>
Diffstat (limited to 'drivers/xen/gntdev.c')
-rw-r--r--drivers/xen/gntdev.c6
1 files changed, 4 insertions, 2 deletions
diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c
index 4b56c39f766d..84b143eef395 100644
--- a/drivers/xen/gntdev.c
+++ b/drivers/xen/gntdev.c
@@ -396,13 +396,15 @@ static void __unmap_grant_pages_done(int result,
unsigned int offset = data->unmap_ops - map->unmap_ops;
for (i = 0; i < data->count; i++) {
- WARN_ON(map->unmap_ops[offset+i].status);
+ WARN_ON(map->unmap_ops[offset + i].status != GNTST_okay &&
+ map->unmap_ops[offset + i].handle != INVALID_GRANT_HANDLE);
pr_debug("unmap handle=%d st=%d\n",
map->unmap_ops[offset+i].handle,
map->unmap_ops[offset+i].status);
map->unmap_ops[offset+i].handle = INVALID_GRANT_HANDLE;
if (use_ptemod) {
- WARN_ON(map->kunmap_ops[offset+i].status);
+ WARN_ON(map->kunmap_ops[offset + i].status != GNTST_okay &&
+ map->kunmap_ops[offset + i].handle != INVALID_GRANT_HANDLE);
pr_debug("kunmap handle=%u st=%d\n",
map->kunmap_ops[offset+i].handle,
map->kunmap_ops[offset+i].status);