From: Alexei Starovoitov <alexei.starovoitov@gmail.com>
To: Hao Luo <haoluo@google.com>
Cc: netdev@vger.kernel.org, bpf@vger.kernel.org,
linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org,
Shuah Khan <shuah@kernel.org>,
Alexei Starovoitov <ast@kernel.org>,
Andrii Nakryiko <andriin@fb.com>,
Daniel Borkmann <daniel@iogearbox.net>,
Martin KaFai Lau <kafai@fb.com>, Song Liu <songliubraving@fb.com>,
Yonghong Song <yhs@fb.com>,
John Fastabend <john.fastabend@gmail.com>,
KP Singh <kpsingh@chromium.org>,
Quentin Monnet <quentin@isovalent.com>,
Steven Rostedt <rostedt@goodmis.org>,
Ingo Molnar <mingo@redhat.com>, Andrey Ignatov <rdna@fb.com>,
Jakub Sitnicki <jakub@cloudflare.com>
Subject: Re: [PATCH bpf-next v1 1/8] bpf: Introduce pseudo_btf_id
Date: Thu, 20 Aug 2020 14:53:27 -0700 [thread overview]
Message-ID: <20200820215327.jsvjbsvv6ts3x4wn@ast-mbp.dhcp.thefacebook.com> (raw)
In-Reply-To: <20200819224030.1615203-2-haoluo@google.com>
On Wed, Aug 19, 2020 at 03:40:23PM -0700, Hao Luo wrote:
> +
> /* verify BPF_LD_IMM64 instruction */
> static int check_ld_imm(struct bpf_verifier_env *env, struct bpf_insn *insn)
> {
> @@ -7234,6 +7296,9 @@ static int check_ld_imm(struct bpf_verifier_env *env, struct bpf_insn *insn)
> return 0;
> }
>
> + if (insn->src_reg == BPF_PSEUDO_BTF_ID)
> + return check_pseudo_btf_id(env, insn);
> +
> map = env->used_maps[aux->map_index];
> mark_reg_known_zero(env, regs, insn->dst_reg);
> regs[insn->dst_reg].map_ptr = map;
> @@ -9255,6 +9320,9 @@ static int replace_map_fd_with_map_ptr(struct bpf_verifier_env *env)
> /* valid generic load 64-bit imm */
> goto next_insn;
>
> + if (insn[0].src_reg == BPF_PSEUDO_BTF_ID)
> + goto next_insn;
> +
Why did you choose to do it during main do_check() walk instead of this pre-pass ?
check_ld_imm() can be called multiple times for the same insn,
so it's faster and less surprising to do it during replace_map_fd_with_map_ptr().
BTF needs to be parsed first, of course.
You can either move check_btf_info() before replace_map_fd_with_map_ptr() or
move replace_map_fd_with_map_ptr() after check_btf_info().
The latter is probably cleaner.
next prev parent reply other threads:[~2020-08-20 21:53 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-19 22:40 [PATCH bpf-next v1 0/8] bpf: BTF support for ksyms Hao Luo
2020-08-19 22:40 ` [PATCH bpf-next v1 1/8] bpf: Introduce pseudo_btf_id Hao Luo
2020-08-20 15:22 ` Yonghong Song
2020-08-20 17:04 ` Hao Luo
2020-08-25 0:05 ` Hao Luo
2020-08-25 0:43 ` Yonghong Song
2020-08-20 16:43 ` Yonghong Song
2020-08-20 21:53 ` Alexei Starovoitov [this message]
2020-08-21 2:22 ` Hao Luo
2020-08-19 22:40 ` [PATCH bpf-next v1 2/8] bpf: Propagate BPF_PSEUDO_BTF_ID to uapi headers in /tools Hao Luo
2020-08-20 16:44 ` Yonghong Song
2020-08-19 22:40 ` [PATCH bpf-next v1 3/8] bpf: Introduce help function to validate ksym's type Hao Luo
2020-08-20 17:20 ` Yonghong Song
2020-08-21 21:50 ` Andrii Nakryiko
2020-08-22 0:43 ` Hao Luo
2020-08-22 2:43 ` Andrii Nakryiko
2020-08-22 7:04 ` Hao Luo
2020-08-19 22:40 ` [PATCH bpf-next v1 4/8] bpf/libbpf: BTF support for typed ksyms Hao Luo
2020-08-21 22:37 ` Andrii Nakryiko
2020-08-27 22:29 ` Hao Luo
2020-09-01 18:11 ` Andrii Nakryiko
2020-09-01 20:35 ` Hao Luo
2020-09-01 23:54 ` Andrii Nakryiko
2020-09-02 0:46 ` Hao Luo
2020-08-19 22:40 ` [PATCH bpf-next v1 5/8] bpf/selftests: ksyms_btf to test " Hao Luo
2020-08-20 17:28 ` Yonghong Song
2020-08-21 23:03 ` Andrii Nakryiko
2020-08-22 7:26 ` Hao Luo
2020-08-22 7:35 ` Andrii Nakryiko
2020-08-19 22:40 ` [PATCH bpf-next v1 6/8] bpf: Introduce bpf_per_cpu_ptr() Hao Luo
2020-08-22 3:26 ` Andrii Nakryiko
2020-08-22 3:31 ` Andrii Nakryiko
2020-08-22 7:49 ` Hao Luo
2020-08-22 7:55 ` Andrii Nakryiko
2020-08-25 1:03 ` Hao Luo
2020-08-19 22:40 ` [PATCH bpf-next v1 7/8] bpf: Propagate bpf_per_cpu_ptr() to /tools Hao Luo
2020-08-20 17:30 ` Yonghong Song
2020-08-19 22:40 ` [PATCH bpf-next v1 8/8] bpf/selftests: Test for bpf_per_cpu_ptr() Hao Luo
2020-08-22 3:30 ` Andrii Nakryiko
2020-08-28 3:42 ` Hao Luo
2020-09-01 18:12 ` Andrii Nakryiko
2020-09-01 19:47 ` Hao Luo
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