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 | 15 +++++++++++++--
1 file changed, 13 insertions(+), 2 deletions(-)
diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c
index 40732e8ed4c6..96d2f3030ebb 100644
--- a/drivers/vfio/vfio_main.c
+++ b/drivers/vfio/vfio_main.c
@@ -938,14 +938,17 @@ 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);
+ if (!comb_start)
+ return;
curr = comb_start;
while (curr) {
last = curr->last;
@@ -963,6 +966,10 @@ void vfio_combine_iova_ranges(struct rb_root_cached *root, u32 cur_nodes,
prev = NULL;
min_gap = ULONG_MAX;
curr = interval_tree_iter_first(root, 0, ULONG_MAX);
+ if (!curr) {
+ /* No more ranges to combine */
+ break;
+ }
while (curr) {
if (prev) {
curr_gap = curr->start - prev->last;
@@ -975,6 +982,10 @@ void vfio_combine_iova_ranges(struct rb_root_cached *root, u32 cur_nodes,
prev = curr;
curr = interval_tree_iter_next(curr, 0, ULONG_MAX);
}
+ if (!comb_start || !comb_end) {
+ /* No more ranges to combine */
+ break;
+ }
comb_start->last = comb_end->last;
interval_tree_remove(comb_end, root);
cur_nodes--;
--
2.34.1
While this may seem somewhat verbose, I am unsure how to refactor this function.
