[BUG]
With valgrind, fsck/002 test with original mode would report the
following valgrind error:
==90600== Conditional jump or move depends on uninitialised value(s)
==90600== at 0x15C280: pick_next_pending (main.c:4949)
==90600== by 0x15F3CF: run_next_block (main.c:6175)
==90600== by 0x1655CC: deal_root_from_list (main.c:8486)
==90600== by 0x1660C7: check_chunks_and_extents (main.c:8762)
==90600== by 0x166439: do_check_chunks_and_extents (main.c:8842)
==90600== by 0x169D0B: cmd_check (main.c:10324)
==90600== by 0x11CDC6: cmd_execute (commands.h:125)
==90600== by 0x11D712: main (btrfs.c:386)
[CAUSE]
The problem happens like this:
deal_root_from_list(@list is empty)
|- stack @last is not initialized
|- while(!list_empty(list)) {} is skipped
|- run_next_block(&last);
|- pick_next_pending(*last);
|- node_start = last;
Since the stack @last is not initialized in deal_root_from_list(), the
final node_start = last assignment would just fetch the garbage from
stack.
[FIX]
Fix the problem by initializing @last to 0, as that's exactly what the
first while loop did.
Signed-off-by: Qu Wenruo <wqu@xxxxxxxx>
---
check/main.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/check/main.c b/check/main.c
index b56255bc10a8..d8181249e394 100644
--- a/check/main.c
+++ b/check/main.c
@@ -8442,7 +8442,7 @@ static int deal_root_from_list(struct list_head *list,
struct device_extent_tree *dev_extent_cache)
{
int ret = 0;
- u64 last;
+ u64 last = 0;
while (!list_empty(list)) {
struct root_item_record *rec;
--
2.25.2
