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References: <20231018180336.1696131-1-song@kernel.org> <20231018180336.1696131-4-song@kernel.org>
 <c1e44b6f-f18d-8c30-3ff7-8af35a0706bf@iogearbox.net>
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From: Song Liu <song@kernel.org>
Date: Tue, 24 Oct 2023 08:45:59 -0700
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Message-ID: <CAPhsuW4LEpELW7GT5Ephe4V8_djub=vaZWUHQhdaWU9ojs=8vg@mail.gmail.com>
Subject: Re: [PATCH v4 bpf-next 3/7] bpf: Add helpers for trampoline image management
To: Daniel Borkmann <daniel@iogearbox.net>
Cc: bpf@vger.kernel.org, ast@kernel.org, andrii@kernel.org, 
	martin.lau@kernel.org, kernel-team@meta.com, 
	Ilya Leoshkevich <iii@linux.ibm.com>
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On Tue, Oct 24, 2023 at 7:46=E2=80=AFAM Daniel Borkmann <daniel@iogearbox.n=
et> wrote:
>
> On 10/18/23 8:03 PM, Song Liu wrote:
> [...]
> > @@ -1040,6 +1038,38 @@ arch_prepare_bpf_trampoline(struct bpf_tramp_ima=
ge *im, void *image, void *image
> >       return -ENOTSUPP;
> >   }
> >
> > +void * __weak arch_alloc_bpf_trampoline(int size)
> > +{
> > +     void *image;
> > +
> > +     WARN_ON_ONCE(size > PAGE_SIZE || size <=3D 0);
>
> non-blocking / can be follow-up, but why not:
>
> if (WARN_ON_ONCE(size > PAGE_SIZE || size <=3D 0))
>         return NULL
>
> size could also be u32, then you don't need size <=3D 0 check ?

Thanks for the suggestion! The code will indeed be cleaner with
these changes.

Song