From: Eduard Zingerman <eddyz87@gmail.com>
To: Andrii Nakryiko <andrii.nakryiko@gmail.com>,
Andrei Matei <andreimatei1@gmail.com>
Cc: bpf@vger.kernel.org, sunhao.th@gmail.com, kernel-team@dataexmachina.dev
Subject: Re: [PATCH bpf v3 3/3] bpf: minor cleanup around stack bounds
Date: Mon, 04 Dec 2023 20:43:41 +0200 [thread overview]
Message-ID: <f3475cc9e9ee50a7fdbbfff353f07067537cf1fd.camel@gmail.com> (raw)
In-Reply-To: <CAEf4BzbT-UBaigkGeimFOTUqadVMbUFJJ7g2gfR-Au3xxHd6Yg@mail.gmail.com>
On Mon, 2023-12-04 at 10:19 -0800, Andrii Nakryiko wrote:
[...]
> > @@ -6828,7 +6831,10 @@ static int check_stack_access_within_bounds(
> > return err;
> > }
> >
> > - return grow_stack_state(env, state, round_up(-min_off, BPF_REG_SIZE));
> > + /* Note that there is no stack access with offset zero, so the needed stack
> > + * size is -min_off, not -min_off+1.
> > + */
> > + return grow_stack_state(env, state, -min_off /* size */);
>
> hmm.. there is still a grow_stack_state() call in
> check_stack_write_fixed_off(), right? Which is not necessary because
> we do check_stack_access_within_bounds() before that one. Can you drop
> it as part of patch #2?
I'm not sure I understand what you mean. Patch #2 (v3) drops
grow_stack_state() from check_stack_write_fixed_off()
so all seems good?
next prev parent reply other threads:[~2023-12-04 18:43 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-12-02 23:05 [PATCH bpf v3 0/3] bpf: fix accesses to uninit stack slots Andrei Matei
2023-12-02 23:05 ` [PATCH bpf v3 1/3] bpf: add some comments to stack representation Andrei Matei
2023-12-04 18:18 ` Andrii Nakryiko
2023-12-04 18:25 ` Eduard Zingerman
2023-12-02 23:05 ` [PATCH bpf v3 2/3] bpf: fix accesses to uninit stack slots Andrei Matei
2023-12-02 23:09 ` Andrei Matei
2023-12-03 13:22 ` Eduard Zingerman
2023-12-04 18:19 ` Andrii Nakryiko
2023-12-02 23:05 ` [PATCH bpf v3 3/3] bpf: minor cleanup around stack bounds Andrei Matei
2023-12-04 18:19 ` Andrii Nakryiko
2023-12-04 18:43 ` Eduard Zingerman [this message]
2023-12-04 19:06 ` Andrii Nakryiko
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