Re: [PATCH bpf-next v10 3/8] bpf: Refactor reporting log_true_size for prog_load

[Alexei Starovoitov]

On Tue, Mar 3, 2026 at 9:47 PM Leon Hwang <leon.hwang@xxxxxxxxx> wrote:
>
> On 4/3/26 00:32, Alexei Starovoitov wrote:
> > On Wed, Feb 11, 2026 at 7:13 AM Leon Hwang <leon.hwang@xxxxxxxxx> wrote:
> >>
>
> [...]
>
> >> @@ -6241,7 +6244,11 @@ static int __sys_bpf(enum bpf_cmd cmd, bpfptr_t uattr, unsigned int size,
> >>                 err = map_freeze(&attr);
> >>                 break;
> >>         case BPF_PROG_LOAD:
> >> -               err = bpf_prog_load(&attr, uattr, size);
> >> +               if (from_user && size >= offsetofend(union bpf_attr, log_true_size))
> >> +                       log_true_size = uattr.user + offsetof(union bpf_attr, log_true_size);
> >
> > So you added 'from_user' gating because
> > you replaced copy_to_bpfptr_offset() with copy_to_user()?
> > This is a drastic change in behavior and you don't even talk about
> > it in the commit log.
> > You said "refactor". This is not a refactoring!
> >
> > This is v10. The common_attr feature is useful, but
> > you really need to think harder about what your patches
> > are doing.
> >
>
> Refactoring should not introduce any functional changes. If a functional
> change is involved, it should be factored out of the refactoring commit
> into a separate commit with an explanation in the commit log.
>
> I'll add this to my self-review checklist.
>
> The intention of 'from_user' was to replace copy_to_bpfptr_offset() with
> copy_to_user(), since the log is always copied to the user-space buffer
> when the log level is not BPF_LOG_KERNEL in
> kernel/bpf/log.c::bpf_verifier_vlog().
>
> The 'from_user' gating will be dropped in v12 to keep this patch as pure
> refactoring.

You were told multiple times to avoid copy pasting AI into your emails.
Sorry, but this crosses the line for me.
Your patches will be ignored for 2 weeks.