From: Yonghong Song <yhs@fb.com>
To: Shung-Hsi Yu <shung-hsi.yu@suse.com>,
linux-kselftest@vger.kernel.org, netdev@vger.kernel.org,
bpf@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: Shuah Khan <shuah@kernel.org>,
Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Andrii Nakryiko <andrii@kernel.org>,
Martin KaFai Lau <kafai@fb.com>, Song Liu <songliubraving@fb.com>,
John Fastabend <john.fastabend@gmail.com>,
KP Singh <kpsingh@kernel.org>
Subject: Re: [PATCH bpf-next 4/4] selftests/bpf: add reason of rejection in ld_imm64
Date: Fri, 20 May 2022 17:27:12 -0700 [thread overview]
Message-ID: <7301b9cc-fdb1-cd4c-2dda-eb97018546a6@fb.com> (raw)
In-Reply-To: <20220520113728.12708-5-shung-hsi.yu@suse.com>
On 5/20/22 4:37 AM, Shung-Hsi Yu wrote:
> It may not be immediately clear why that ld_imm64 test cases are
> rejected, especially for test1 and test2 where JMP to the 2nd
> instruction of BPF_LD_IMM64 is performed.
>
> Add brief explaination of why each test case in verifier/ld_imm64.c
> should be rejected.
>
> Signed-off-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
> ---
> .../testing/selftests/bpf/verifier/ld_imm64.c | 20 ++++++++++---------
> 1 file changed, 11 insertions(+), 9 deletions(-)
>
> diff --git a/tools/testing/selftests/bpf/verifier/ld_imm64.c b/tools/testing/selftests/bpf/verifier/ld_imm64.c
> index f9297900cea6..021312641aaf 100644
> --- a/tools/testing/selftests/bpf/verifier/ld_imm64.c
> +++ b/tools/testing/selftests/bpf/verifier/ld_imm64.c
> @@ -1,5 +1,6 @@
> +/* Note: BPF_LD_IMM64 is composed of two instructions of class BPF_LD */
> [...]LD | BPF_IMM | BPF_DW, 0, 0, 0, 0),
> @@ -42,7 +43,7 @@
> .result = REJECT,
> },
> {
> - "test4 ld_imm64",
> + "test4 ld_imm64: reject incomplete BPF_LD_IMM64 instruction",
> .insns = {
> BPF_RAW_INSN(BPF_LD | BPF_IMM | BPF_DW, 0, 0, 0, 0),
> BPF_EXIT_INSN(),
> @@ -70,7 +71,7 @@
> .retval = 1,
> },
> {
> - "test8 ld_imm64",
> + "test8 ld_imm64: reject 1st off!=0",
Let add some space like 'off != 0'. The same for
some of later test names.
> .insns = {
> BPF_RAW_INSN(BPF_LD | BPF_IMM | BPF_DW, 0, 0, 1, 1),
> BPF_RAW_INSN(0, 0, 0, 0, 1),
> @@ -80,7 +81,7 @@
> .result = REJECT,
> },
> {
> - "test9 ld_imm64",
> + "test9 ld_imm64: reject 2nd off!=0",
> .insns = {
> BPF_RAW_INSN(BPF_LD | BPF_IMM | BPF_DW, 0, 0, 0, 1),
> BPF_RAW_INSN(0, 0, 0, 1, 1),
> @@ -90,7 +91,7 @@
> .result = REJECT,
> },
> {
> - "test10 ld_imm64",
> + "test10 ld_imm64: reject 2nd dst_reg!=0",
> .insns = {
> BPF_RAW_INSN(BPF_LD | BPF_IMM | BPF_DW, 0, 0, 0, 1),
> BPF_RAW_INSN(0, BPF_REG_1, 0, 0, 1),
> @@ -100,7 +101,7 @@
> .result = REJECT,
> },
> {
> - "test11 ld_imm64",
> + "test11 ld_imm64: reject 2nd src_reg!=0",
> .insns = {
> BPF_RAW_INSN(BPF_LD | BPF_IMM | BPF_DW, 0, 0, 0, 1),
> BPF_RAW_INSN(0, 0, BPF_REG_1, 0, 1),
> @@ -113,6 +114,7 @@
> "test12 ld_imm64",
> .insns = {
> BPF_MOV64_IMM(BPF_REG_1, 0),
> + /* BPF_REG_1 is interpreted as BPF_PSEUDO_MAP_FD */
> BPF_RAW_INSN(BPF_LD | BPF_IMM | BPF_DW, 0, BPF_REG_1, 0, 1),
> BPF_RAW_INSN(0, 0, 0, 0, 0),
> BPF_EXIT_INSN(),
> @@ -121,7 +123,7 @@
> .result = REJECT,
> },
> {
> - "test13 ld_imm64",
> + "test13 ld_imm64: 2nd src_reg!=0",
> .insns = {
> BPF_MOV64_IMM(BPF_REG_1, 0),
> BPF_RAW_INSN(BPF_LD | BPF_IMM | BPF_DW, 0, BPF_REG_1, 0, 1),
next prev parent reply other threads:[~2022-05-21 0:27 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-05-20 11:37 [PATCH bpf-next 0/4] bpf: verifier: remove redundant opcode checks Shung-Hsi Yu
2022-05-20 11:37 ` [PATCH bpf-next 1/4] bpf: verifier: update resolve_pseudo_ldimm64() comment Shung-Hsi Yu
2022-05-20 11:37 ` [PATCH bpf-next 2/4] bpf: verifier: explain opcode check in check_ld_imm() Shung-Hsi Yu
2022-05-20 23:50 ` Yonghong Song
2022-05-21 0:25 ` Yonghong Song
2022-05-24 7:10 ` Shung-Hsi Yu
2022-05-24 15:12 ` Alexei Starovoitov
2022-05-26 8:59 ` Shung-Hsi Yu
2022-05-20 11:37 ` [PATCH bpf-next 3/4] bpf: verifier: remove redundant opcode checks Shung-Hsi Yu
2022-05-20 22:46 ` Alexei Starovoitov
2022-05-20 11:37 ` [PATCH bpf-next 4/4] selftests/bpf: add reason of rejection in ld_imm64 Shung-Hsi Yu
2022-05-21 0:27 ` Yonghong Song [this message]
2022-05-24 4:49 ` Shung-Hsi Yu
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