On 10/26/2022 3:52 PM, Bagas Sanjaya wrote:
On Tue, Oct 25, 2022 at 11:32:55PM -0700, Alexei Starovoitov wrote:
On Tue, Oct 25, 2022 at 7:42 PM Xu Kuohai <xukuohai@xxxxxxxxxxxxxxx> wrote:
From: Xu Kuohai <xukuohai@xxxxxxxxxx>
There is a typo in comment for DFS algorithm in bpf/verifier.c. The top
element should not be popped until all its neighbors have been checked.
Fix it.
Fixes: 475fb78fbf48 ("bpf: verifier (add branch/goto checks)")
Signed-off-by: Xu Kuohai <xukuohai@xxxxxxxxxx>
---
kernel/bpf/verifier.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index b83a8d420520..96ba5ea6d1a6 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -10662,7 +10662,7 @@ static int check_return_code(struct bpf_verifier_env *env)
* 3 let S be a stack
* 4 S.push(v)
* 5 while S is not empty
- * 6 t <- S.pop()
+ * 6 t <- S.top()
Even with this fix the comment is not quite accurate.
I wonder whether we should keep it or delete it completely.
At least please use 'peek' instead of 'top'.
I think the comment should be in words (like other code comments in the
kernel) instead.
The beginning of the comment already says this is a piece of pseudo code. And
I don't think it's clearer to describe the algorithm in words than to describe
it in pseudo code.
