From: Daniel Borkmann <daniel@iogearbox.net>
To: Roman Gushchin <guro@fb.com>, netdev@vger.kernel.org
Cc: linux-kernel@vger.kernel.org, kernel-team@fb.com,
Alexei Starovoitov <ast@kernel.org>
Subject: Re: [PATCH v4 bpf-next 08/14] bpf: introduce the bpf_get_local_storage() helper function
Date: Wed, 1 Aug 2018 00:50:16 +0200 [thread overview]
Message-ID: <ad6c58e3-08a8-aa9c-2d69-528007fe126e@iogearbox.net> (raw)
In-Reply-To: <20180727215243.3850-9-guro@fb.com>
On 07/27/2018 11:52 PM, Roman Gushchin wrote:
[...]
> @@ -2533,6 +2541,16 @@ static int check_helper_call(struct bpf_verifier_env *env, int func_id, int insn
> }
>
> regs = cur_regs(env);
> +
> + /* check that flags argument in get_local_storage(map, flags) is 0,
> + * this is required because get_local_storage() can't return an error.
> + */
> + if (func_id == BPF_FUNC_get_local_storage &&
> + !tnum_equals_const(regs[BPF_REG_2].var_off, 0)) {
> + verbose(env, "get_local_storage() doesn't support non-zero flags\n");
> + return -EINVAL;
> + }
Hmm, this check is actually not correct. You will still be able to pass non-zero
values in there. arg2_type from the helper is ARG_ANYTHING, so the register type
could for example be one of the pointer types and it will still pass the verifier.
The correct way to check would be to use register_is_null().
> +
> /* reset caller saved regs */
> for (i = 0; i < CALLER_SAVED_REGS; i++) {
> mark_reg_not_init(env, regs, caller_saved[i]);
next prev parent reply other threads:[~2018-07-31 22:50 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-07-27 21:52 [PATCH v4 bpf-next 00/14] bpf: cgroup local storage Roman Gushchin
2018-07-27 21:52 ` [PATCH v4 bpf-next 01/14] bpf: add ability to charge bpf maps memory dynamically Roman Gushchin
2018-07-27 21:52 ` [PATCH v4 bpf-next 02/14] bpf: introduce cgroup storage maps Roman Gushchin
2018-07-27 21:52 ` [PATCH v4 bpf-next 03/14] bpf: pass a pointer to a cgroup storage using pcpu variable Roman Gushchin
2018-07-27 21:52 ` [PATCH v4 bpf-next 04/14] bpf: allocate cgroup storage entries on attaching bpf programs Roman Gushchin
2018-07-27 21:52 ` [PATCH v4 bpf-next 05/14] bpf: extend bpf_prog_array to store pointers to the cgroup storage Roman Gushchin
2018-07-27 21:52 ` [PATCH v4 bpf-next 06/14] bpf/verifier: introduce BPF_PTR_TO_MAP_VALUE Roman Gushchin
2018-07-27 21:52 ` [PATCH v4 bpf-next 07/14] bpf: don't allow create maps of cgroup local storages Roman Gushchin
2018-07-27 21:52 ` [PATCH v4 bpf-next 08/14] bpf: introduce the bpf_get_local_storage() helper function Roman Gushchin
2018-07-31 10:34 ` Daniel Borkmann
2018-07-31 17:24 ` Roman Gushchin
2018-07-31 22:50 ` Daniel Borkmann [this message]
2018-08-01 0:28 ` Roman Gushchin
2018-08-01 20:15 ` Daniel Borkmann
2018-07-27 21:52 ` [PATCH v4 bpf-next 09/14] bpf: sync bpf.h to tools/ Roman Gushchin
2018-07-27 21:52 ` [PATCH v4 bpf-next 10/14] bpftool: add support for CGROUP_STORAGE maps Roman Gushchin
2018-07-27 21:52 ` [PATCH v4 bpf-next 11/14] bpf/test_run: support cgroup local storage Roman Gushchin
2018-07-27 21:52 ` [PATCH v4 bpf-next 12/14] selftests/bpf: add verifier cgroup storage tests Roman Gushchin
2018-07-27 21:52 ` [PATCH v4 bpf-next 13/14] selftests/bpf: add a cgroup storage test Roman Gushchin
2018-07-27 21:52 ` [PATCH v4 bpf-next 14/14] samples/bpf: extend test_cgrp2_attach2 test to use cgroup storage Roman Gushchin
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