Re: [PATCH bpf-next v2 3/8] bpf, iter: Fix the condition on p when calling stop.

From: Yonghong Song
Date: Fri Jun 24 2022 - 13:47:01 EST




On 6/21/22 12:25 AM, Hao Luo wrote:
On Mon, Jun 20, 2022 at 11:48 AM Yonghong Song <yhs@xxxxxx> wrote:

On 6/10/22 12:44 PM, Yosry Ahmed wrote:
From: Hao Luo <haoluo@xxxxxxxxxx>

In bpf_seq_read, seq->op->next() could return an ERR and jump to
the label stop. However, the existing code in stop does not handle
the case when p (returned from next()) is an ERR. Adds the handling
of ERR of p by converting p into an error and jumping to done.

Because all the current implementations do not have a case that
returns ERR from next(), so this patch doesn't have behavior changes
right now.

Signed-off-by: Hao Luo <haoluo@xxxxxxxxxx>
Signed-off-by: Yosry Ahmed <yosryahmed@xxxxxxxxxx>

Acked-by: Yonghong Song <yhs@xxxxxx>

Yonghong, do you want to get this change in now, or you want to wait
for the whole patchset? This fix is straightforward and independent of
other parts. Yosry and I can rebase.

Sorry for delay. Let me review other patches as well before your next version.

BTW, I would be great if you just put the prerequisite patch

https://lore.kernel.org/bpf/20220421140740.459558-5-benjamin.tissoires@xxxxxxxxxx/
as the first patch so at least BPF CI will be able to test
your patch set. It looks like KP's bpf_getxattr patch set already did this.

https://lore.kernel.org/bpf/20220624045636.3668195-2-kpsingh@xxxxxxxxxx/T/#u