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| author |   Demi Marie Obenour <demi@invisiblethingslab.com> | 2022-07-10 19:05:22 -0400 |
|---|---|---|
| committer |   Juergen Gross <jgross@suse.com> | 2022-07-11 11:39:45 +0200 |
| commit | 166d3863231667c4f64dee72b77d1102cdfad11f (patch) | |
| tree | 2ffdcc5ef15b616ef1f9f160d3da75e061bb0cc7 /drivers | |
| parent | xen/gntdev: Avoid blocking in unmap_grant_pages() (diff) | |
| download | linux-dev-166d3863231667c4f64dee72b77d1102cdfad11f.tar.xz linux-dev-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')
| -rw-r--r-- | drivers/xen/gntdev.c | 6 |
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); |