Re: [OFFLIST RFC 3/4] bpf: Support bpf_kptr_xchg into local kptr

On Mon, Jul 22, 2024 at 5:18 PM Alexei Starovoitov
[off-list ref] wrote:

On Fri, Jul 19, 2024 at 05:21:18PM +0000, Amery Hung wrote:

quoted

From: Dave Marchevsky <redacted>

Signed-off-by: Dave Marchevsky <redacted>

Amery,
please add your SOB after Dave's when you're sending patches like this.

Remove OFFLIST in subject... and resend cc-ing bpf@vger.

Add proper commit log.

Got it.

quoted

-     if (meta->func_id == BPF_FUNC_kptr_xchg && type_is_alloc(type)) {
+     if (meta->func_id == BPF_FUNC_kptr_xchg && type_is_alloc(type) && regno > 1) {

I don't understand the point of regno > 1. Pls explain/add comment.

Patches 1 and 2 make sense.

I believe this patchset is incomplete, and it will trigger a refcount
bug when running local_kptr_stash/local_kptr_stash_simple. I will
finish and resend this individual series.

Thank you,
Amery