From: Eduard Zingerman <eddyz87@gmail.com>
To: Andrii Nakryiko <andrii.nakryiko@gmail.com>
Cc: Andrii Nakryiko <andrii@kernel.org>,
bpf@vger.kernel.org, ast@kernel.org, daniel@iogearbox.net,
martin.lau@kernel.org, kernel-team@meta.com
Subject: Re: [PATCH bpf-next 5/7] bpf: preserve STACK_ZERO slots on partial reg spills
Date: Thu, 09 Nov 2023 19:54:27 +0200 [thread overview]
Message-ID: <a004428f6884acf4bf1dbdb7aede9ca5a15cc7d6.camel@gmail.com> (raw)
In-Reply-To: <CAEf4Bzb0SY9uoc268qanOcCQ0_8k21WzLtHzj-KM6U_=9W8XXQ@mail.gmail.com>
On Thu, 2023-11-09 at 09:37 -0800, Andrii Nakryiko wrote:
[...]
> > > @@ -1355,6 +1355,21 @@ static void scrub_spilled_slot(u8 *stype)
> > > *stype = STACK_MISC;
> > > }
> > >
> > > +/* Mark stack slot as STACK_MISC, unless it is already STACK_INVALID, in which
> > > + * case they are equivalent, or it's STACK_ZERO, in which case we preserve
> > > + * more precise STACK_ZERO.
> > > + * Note, in uprivileged mode leaving STACK_INVALID is wrong, so we take
> > > + * env->allow_ptr_leaks into account and force STACK_MISC, if necessary.
> > > + */
> > > +static void mark_stack_slot_misc(struct bpf_verifier_env *env, u8 *stype)
> >
> > Nitpick: I find this name misleading, maybe something like "remove_spill_mark"?
>
> remove_spill_mark is even more misleading, no? there is also DYNPTR
> and ITER stack slots?
Right, forgot about those...
>
> maybe mark_stack_slot_scalar (though that's a bit misleading as well,
> as can be understood as marking slot as spilled SCALAR_VALUE
> register)? not sure, I think "slot_misc" is close enough as an
> approximation of what it's doing, modulo ZERO/INVALID
maybe_mark_stack_slot_misc?
The other similar function is named 'scrub_spilled_slot'.
next prev parent reply other threads:[~2023-11-09 17:54 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-10-31 5:03 [PATCH bpf-next 0/7] Complete BPF verifier precision tracking support for register spills Andrii Nakryiko
2023-10-31 5:03 ` [PATCH bpf-next 1/7] bpf: use common jump (instruction) history across all states Andrii Nakryiko
2023-11-09 15:20 ` Eduard Zingerman
2023-11-09 16:13 ` Alexei Starovoitov
2023-11-09 17:28 ` Andrii Nakryiko
2023-11-09 19:29 ` Alexei Starovoitov
2023-11-09 19:49 ` Andrii Nakryiko
2023-11-09 20:39 ` Andrii Nakryiko
2023-11-09 22:05 ` Alexei Starovoitov
2023-11-09 22:57 ` Andrii Nakryiko
2023-11-11 4:29 ` Andrii Nakryiko
2023-10-31 5:03 ` [PATCH bpf-next 2/7] bpf: support non-r10 register spill/fill to/from stack in precision tracking Andrii Nakryiko
2023-11-09 15:20 ` Eduard Zingerman
2023-11-09 17:20 ` Andrii Nakryiko
2023-11-09 18:20 ` Eduard Zingerman
2023-11-10 5:48 ` Andrii Nakryiko
2023-11-12 1:57 ` Andrii Nakryiko
2023-11-12 14:05 ` Eduard Zingerman
2023-10-31 5:03 ` [PATCH bpf-next 3/7] bpf: enforce precision for r0 on callback return Andrii Nakryiko
2023-11-09 15:20 ` Eduard Zingerman
2023-11-09 17:32 ` Andrii Nakryiko
2023-11-09 17:38 ` Eduard Zingerman
2023-11-09 17:50 ` Andrii Nakryiko
2023-11-09 17:58 ` Alexei Starovoitov
2023-11-09 18:01 ` Andrii Nakryiko
2023-11-09 18:03 ` Eduard Zingerman
2023-11-09 18:00 ` Eduard Zingerman
2023-10-31 5:03 ` [PATCH bpf-next 4/7] bpf: fix check for attempt to corrupt spilled pointer Andrii Nakryiko
2023-11-09 15:20 ` Eduard Zingerman
2023-10-31 5:03 ` [PATCH bpf-next 5/7] bpf: preserve STACK_ZERO slots on partial reg spills Andrii Nakryiko
2023-11-09 15:20 ` Eduard Zingerman
2023-11-09 17:37 ` Andrii Nakryiko
2023-11-09 17:54 ` Eduard Zingerman [this message]
2023-10-31 5:03 ` [PATCH bpf-next 6/7] bpf: preserve constant zero when doing partial register restore Andrii Nakryiko
2023-11-09 15:20 ` Eduard Zingerman
2023-11-09 17:41 ` Andrii Nakryiko
2023-11-09 19:34 ` Eduard Zingerman
2023-10-31 5:03 ` [PATCH bpf-next 7/7] bpf: track aligned STACK_ZERO cases as imprecise spilled registers Andrii Nakryiko
2023-10-31 5:22 ` Andrii Nakryiko
2023-11-01 7:56 ` Jiri Olsa
2023-11-01 16:27 ` Andrii Nakryiko
2023-11-02 9:54 ` Jiri Olsa
2023-11-09 15:21 ` Eduard Zingerman
2023-11-09 17:43 ` Andrii Nakryiko
2023-11-09 17:44 ` Eduard Zingerman
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