On Tue, Sep 12, 2023 at 09:07:36AM +0800, Cong Liu wrote:
> when compiling with smatch check, the following errors were encountered:
>
> drivers/vfio/vfio_main.c:957 vfio_combine_iova_ranges() error: uninitialized symbol 'last'.
> drivers/vfio/vfio_main.c:978 vfio_combine_iova_ranges() error: potentially dereferencing uninitialized 'comb_end'.
> drivers/vfio/vfio_main.c:978 vfio_combine_iova_ranges() error: potentially dereferencing uninitialized 'comb_start'.
>
> this patch fix these error.
>
> Signed-off-by: Cong Liu <liucong2@xxxxxxxxxx>
> ---
> drivers/vfio/vfio_main.c | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c
> index 40732e8ed4c6..68a0a5081161 100644
> --- a/drivers/vfio/vfio_main.c
> +++ b/drivers/vfio/vfio_main.c
> @@ -938,12 +938,13 @@ static int vfio_ioctl_device_feature_migration(struct vfio_device *device,
> void vfio_combine_iova_ranges(struct rb_root_cached *root, u32 cur_nodes,
> u32 req_nodes)
> {
> - struct interval_tree_node *prev, *curr, *comb_start, *comb_end;
> + struct interval_tree_node *prev, *curr;
> + struct interval_tree_node *comb_start = NULL, *comb_end = NULL;
> unsigned long min_gap, curr_gap;
>
> /* Special shortcut when a single range is required */
> if (req_nodes == 1) {
> - unsigned long last;
> + unsigned long last = 0;
>
> comb_start = interval_tree_iter_first(root, 0, ULONG_MAX);
> curr = comb_start;
These are not possible unless the list is empty, and assigning
zero/null isn't an improvement for that case it will just crash
Jason
