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From:   Xu Kuohai <xukuohai@huaweicloud.com>
To:     bpf@vger.kernel.org, linux-kselftest@vger.kernel.org,
        linux-kernel@vger.kernel.org
Cc:     Alexei Starovoitov <ast@kernel.org>,
        Daniel Borkmann <daniel@iogearbox.net>,
        John Fastabend <john.fastabend@gmail.com>,
        Andrii Nakryiko <andrii@kernel.org>,
        Martin KaFai Lau <martin.lau@linux.dev>,
        Song Liu <song@kernel.org>, Yonghong Song <yhs@fb.com>,
        KP Singh <kpsingh@kernel.org>,
        Stanislav Fomichev <sdf@google.com>,
        Hao Luo <haoluo@google.com>, Jiri Olsa <jolsa@kernel.org>,
        Mykola Lysenko <mykolal@fb.com>, Shuah Khan <shuah@kernel.org>
Subject: [PATCH bpf-next v2 2/2] selftests/bpf: check if verifier tracks dst_reg bound for BPF_MOD
Date:   Fri, 24 Mar 2023 00:58:42 -0400
Message-Id: <20230324045842.729719-3-xukuohai@huaweicloud.com>
In-Reply-To: <20230324045842.729719-1-xukuohai@huaweicloud.com>
References: <20230324045842.729719-1-xukuohai@huaweicloud.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

From: Xu Kuohai <xukuohai@huawei.com>

Test cases to check if verifier tracks dst_reg bound for BPF_MOD.

Signed-off-by: Xu Kuohai <xukuohai@huawei.com>
---
 tools/testing/selftests/bpf/verifier/mod.c | 320 +++++++++++++++++++++
 1 file changed, 320 insertions(+)
 create mode 100644 tools/testing/selftests/bpf/verifier/mod.c

diff --git a/tools/testing/selftests/bpf/verifier/mod.c b/tools/testing/selftests/bpf/verifier/mod.c
new file mode 100644
index 000000000000..3aec856d5c9f
--- /dev/null
+++ b/tools/testing/selftests/bpf/verifier/mod.c
@@ -0,0 +1,320 @@
+{
+	"mod64 positive imm",
+	.insns = {
+	BPF_MOV64_IMM(BPF_REG_0, 0),
+	BPF_ALU64_IMM(BPF_MOD, BPF_REG_0, 1),
+
+	BPF_MOV64_IMM(BPF_REG_1, 0),
+	BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 1),
+	/* r0 = 0 */
+	BPF_JMP_REG(BPF_JLT, BPF_REG_1, BPF_REG_0, -2),
+
+	BPF_EXIT_INSN(),
+	},
+	.result = ACCEPT,
+	.prog_type = BPF_PROG_TYPE_XDP,
+},
+{
+	"mod64 positive reg",
+	.insns = {
+	BPF_MOV64_IMM(BPF_REG_0, 0),
+	BPF_MOV64_IMM(BPF_REG_1, 1),
+	BPF_ALU64_REG(BPF_MOD, BPF_REG_0, BPF_REG_1),
+
+	BPF_MOV64_IMM(BPF_REG_1, 0),
+	BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 1),
+	/* r0 = 0 */
+	BPF_JMP_REG(BPF_JLT, BPF_REG_1, BPF_REG_0, -2),
+
+	BPF_EXIT_INSN(),
+	},
+	.result = ACCEPT,
+	.prog_type = BPF_PROG_TYPE_XDP,
+},
+{
+	"mod64 zero",
+	.insns = {
+	BPF_MOV64_IMM(BPF_REG_0, 0),
+	BPF_MOV64_IMM(BPF_REG_1, 0),
+	BPF_ALU64_REG(BPF_MOD, BPF_REG_0, BPF_REG_1),
+
+	BPF_MOV64_IMM(BPF_REG_1, 0),
+	BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 1),
+	/* r0 = 0 */
+	BPF_JMP_REG(BPF_JLT, BPF_REG_1, BPF_REG_0, -2),
+
+	BPF_EXIT_INSN(),
+	},
+	.result = ACCEPT,
+	.prog_type = BPF_PROG_TYPE_XDP,
+},
+{
+	"mod64 negative 1",
+	.insns = {
+	BPF_MOV64_IMM(BPF_REG_0, 1),
+	BPF_MOV64_IMM(BPF_REG_1, -1),
+	BPF_ALU64_REG(BPF_MOD, BPF_REG_0, BPF_REG_1),
+
+	BPF_MOV64_IMM(BPF_REG_1, 0),
+	BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 1),
+	/* r0 = 1 */
+	BPF_JMP_REG(BPF_JLT, BPF_REG_1, BPF_REG_0, -2),
+
+	BPF_EXIT_INSN(),
+	},
+	.result = ACCEPT,
+	.prog_type = BPF_PROG_TYPE_XDP,
+	.retval = 1,
+},
+{
+	"mod64 negative 2",
+	.insns = {
+	BPF_MOV64_IMM(BPF_REG_0, -4),
+	BPF_MOV32_IMM(BPF_REG_1, 5),
+	BPF_ALU64_REG(BPF_MOD, BPF_REG_0, BPF_REG_1),
+
+	BPF_MOV64_IMM(BPF_REG_1, 0),
+	BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 1),
+	/* r0 = 2 */
+	BPF_JMP_REG(BPF_JLT, BPF_REG_1, BPF_REG_0, -2),
+
+	BPF_EXIT_INSN(),
+	},
+	.result = ACCEPT,
+	.prog_type = BPF_PROG_TYPE_XDP,
+	.retval = 2,
+},
+{
+	"mod64 negative 3",
+	.insns = {
+	BPF_MOV32_IMM(BPF_REG_0, -4),
+	BPF_MOV32_IMM(BPF_REG_1, -5),
+	BPF_ALU64_REG(BPF_MOD, BPF_REG_0, BPF_REG_1),
+
+	BPF_MOV64_IMM(BPF_REG_1, 0),
+	BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 1),
+	/* r0 = 1 */
+	BPF_JMP_REG(BPF_JLT, BPF_REG_1, BPF_REG_0, -2),
+
+	BPF_EXIT_INSN(),
+	},
+	.result = ACCEPT,
+	.prog_type = BPF_PROG_TYPE_XDP,
+	.retval = 1,
+},
+{
+	"mod64 variable dividend cross signed boundary, with JLT",
+	.insns = {
+	BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1,
+		    offsetof(struct xdp_md, data)),
+	BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1,
+		    offsetof(struct xdp_md, data_end)),
+	BPF_MOV64_REG(BPF_REG_1, BPF_REG_2),
+	BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 1),
+	BPF_JMP_REG(BPF_JGT, BPF_REG_1, BPF_REG_3, 11),
+
+	BPF_LDX_MEM(BPF_B, BPF_REG_1, BPF_REG_2, 0),
+	BPF_LD_IMM64(BPF_REG_0, 0x7fffffffffffff10),
+	BPF_ALU64_REG(BPF_ADD, BPF_REG_1, BPF_REG_0),
+	BPF_LD_IMM64(BPF_REG_0, 0x80000000000000ff),
+	BPF_ALU64_REG(BPF_MOD, BPF_REG_1, BPF_REG_0),
+
+	BPF_LD_IMM64(BPF_REG_0, 0x8000000000000000),
+	BPF_ALU64_IMM(BPF_ADD, BPF_REG_0, 1),
+	/* r1 unsigned range is [0x7fffffffffffff10, 0x800000000000000f] */
+	BPF_JMP_REG(BPF_JLT, BPF_REG_0, BPF_REG_1, -2),
+
+	BPF_MOV64_IMM(BPF_REG_0, 0),
+	BPF_EXIT_INSN(),
+	},
+	.result = ACCEPT,
+	.prog_type = BPF_PROG_TYPE_XDP,
+},
+{
+	"mod64 variable dividend cross signed boundary, with JSLT",
+	.insns = {
+	BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1,
+		    offsetof(struct xdp_md, data)),
+	BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1,
+		    offsetof(struct xdp_md, data_end)),
+	BPF_MOV64_REG(BPF_REG_1, BPF_REG_2),
+	BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 1),
+	BPF_JMP_REG(BPF_JGT, BPF_REG_1, BPF_REG_3, 11),
+
+	BPF_LDX_MEM(BPF_B, BPF_REG_1, BPF_REG_2, 0),
+	BPF_LD_IMM64(BPF_REG_0, 0x7fffffffffffff10),
+	BPF_ALU64_REG(BPF_ADD, BPF_REG_1, BPF_REG_0),
+	BPF_LD_IMM64(BPF_REG_0, 0x80000000000000ff),
+	BPF_ALU64_REG(BPF_MOD, BPF_REG_1, BPF_REG_0),
+
+	BPF_LD_IMM64(BPF_REG_0, 0x8000000000000000),
+	BPF_ALU64_IMM(BPF_ADD, BPF_REG_0, 1),
+	/* r1 signed range is [S64_MIN, S64_MAX] */
+	BPF_JMP_REG(BPF_JSLT, BPF_REG_0, BPF_REG_1, -2),
+
+	BPF_MOV64_IMM(BPF_REG_0, 0),
+	BPF_EXIT_INSN(),
+	},
+	.errstr = "BPF program is too large.",
+	.result = REJECT,
+	.prog_type = BPF_PROG_TYPE_XDP,
+},
+{
+	"mod32 positive imm",
+	.insns = {
+	BPF_MOV32_IMM(BPF_REG_0, 0),
+	BPF_ALU32_IMM(BPF_MOD, BPF_REG_0, 1),
+
+	BPF_MOV64_IMM(BPF_REG_1, 0),
+	BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 1),
+	/* r0 = 0 */
+	BPF_JMP_REG(BPF_JLT, BPF_REG_1, BPF_REG_0, -2),
+
+	BPF_EXIT_INSN(),
+	},
+	.result = ACCEPT,
+	.prog_type = BPF_PROG_TYPE_XDP,
+},
+{
+	"mod32 positive reg",
+	.insns = {
+	BPF_MOV32_IMM(BPF_REG_0, 0),
+	BPF_MOV32_IMM(BPF_REG_1, 1),
+	BPF_ALU32_REG(BPF_MOD, BPF_REG_0, BPF_REG_1),
+
+	BPF_MOV64_IMM(BPF_REG_1, 0),
+	BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 1),
+	/* r0 = 0 */
+	BPF_JMP_REG(BPF_JLT, BPF_REG_1, BPF_REG_0, -2),
+
+	BPF_EXIT_INSN(),
+	},
+	.result = ACCEPT,
+	.prog_type = BPF_PROG_TYPE_XDP,
+},
+{
+	"mod32 zero",
+	.insns = {
+	BPF_MOV32_IMM(BPF_REG_0, 0),
+	BPF_MOV32_IMM(BPF_REG_1, 0),
+	BPF_ALU32_REG(BPF_MOD, BPF_REG_0, BPF_REG_1),
+
+	BPF_MOV64_IMM(BPF_REG_1, 0),
+	BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 1),
+	/* r0 = 0 */
+	BPF_JMP_REG(BPF_JLT, BPF_REG_1, BPF_REG_0, -2),
+
+	BPF_EXIT_INSN(),
+	},
+	.result = ACCEPT,
+	.prog_type = BPF_PROG_TYPE_XDP,
+},
+{
+	"mod32 negative 1",
+	.insns = {
+	BPF_MOV32_IMM(BPF_REG_0, 1),
+	BPF_MOV32_IMM(BPF_REG_1, -1),
+	BPF_ALU32_REG(BPF_MOD, BPF_REG_0, BPF_REG_1),
+
+	BPF_MOV64_IMM(BPF_REG_1, 0),
+	BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 1),
+	/* r0 = 1 */
+	BPF_JMP_REG(BPF_JLT, BPF_REG_1, BPF_REG_0, -2),
+
+	BPF_EXIT_INSN(),
+	},
+	.result = ACCEPT,
+	.prog_type = BPF_PROG_TYPE_XDP,
+	.retval = 1,
+},
+{
+	"mod32 negative 2",
+	.insns = {
+	BPF_MOV32_IMM(BPF_REG_0, -4),
+	BPF_MOV32_IMM(BPF_REG_1, 5),
+	BPF_ALU32_REG(BPF_MOD, BPF_REG_0, BPF_REG_1),
+
+	BPF_MOV64_IMM(BPF_REG_1, 0),
+	BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 1),
+	/* r0 = 2 */
+	BPF_JMP_REG(BPF_JLT, BPF_REG_1, BPF_REG_0, -2),
+
+	BPF_EXIT_INSN(),
+	},
+	.result = ACCEPT,
+	.prog_type = BPF_PROG_TYPE_XDP,
+	.retval = 2,
+},
+{
+	"mod32 negative 3",
+	.insns = {
+	BPF_MOV32_IMM(BPF_REG_0, -4),
+	BPF_MOV32_IMM(BPF_REG_1, -5),
+	BPF_ALU32_REG(BPF_MOD, BPF_REG_0, BPF_REG_1),
+
+	BPF_MOV64_IMM(BPF_REG_1, 0),
+	BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 1),
+	/* r0 = 1 */
+	BPF_JMP_REG(BPF_JLT, BPF_REG_1, BPF_REG_0, -2),
+
+	BPF_EXIT_INSN(),
+	},
+	.result = ACCEPT,
+	.prog_type = BPF_PROG_TYPE_XDP,
+	.retval = 1,
+},
+{
+	"mod32 variable dividend cross signed boundary, with JLT",
+	.insns = {
+	BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1,
+		    offsetof(struct xdp_md, data)),
+	BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1,
+		    offsetof(struct xdp_md, data_end)),
+	BPF_MOV64_REG(BPF_REG_1, BPF_REG_2),
+	BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 1),
+	BPF_JMP_REG(BPF_JGT, BPF_REG_1, BPF_REG_3, 7),
+
+	BPF_LDX_MEM(BPF_B, BPF_REG_1, BPF_REG_2, 0),
+	BPF_MOV64_IMM(BPF_REG_0, 0x7fffff10),
+	BPF_ALU64_REG(BPF_ADD, BPF_REG_1, BPF_REG_0),
+	BPF_ALU32_IMM(BPF_MOD, BPF_REG_1, 0x800000ff),
+
+	BPF_MOV32_IMM(BPF_REG_0, 0x80000000),
+	BPF_ALU32_IMM(BPF_ADD, BPF_REG_0, 1),
+	/* r1 unsigned 32-bit range is [0x7fffff10, 0x8000000f] */
+	BPF_JMP32_REG(BPF_JLT, BPF_REG_0, BPF_REG_1, -2),
+
+	BPF_MOV64_IMM(BPF_REG_0, 0),
+	BPF_EXIT_INSN(),
+	},
+	.result = ACCEPT,
+	.prog_type = BPF_PROG_TYPE_XDP,
+},
+{
+	"mod32 variable dividend cross signed boundary, with JSLT",
+	.insns = {
+	BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1,
+		    offsetof(struct xdp_md, data)),
+	BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1,
+		    offsetof(struct xdp_md, data_end)),
+	BPF_MOV64_REG(BPF_REG_1, BPF_REG_2),
+	BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 1),
+	BPF_JMP_REG(BPF_JGT, BPF_REG_1, BPF_REG_3, 7),
+
+	BPF_LDX_MEM(BPF_B, BPF_REG_1, BPF_REG_2, 0),
+	BPF_MOV64_IMM(BPF_REG_0, 0x7fffff10),
+	BPF_ALU64_REG(BPF_ADD, BPF_REG_1, BPF_REG_0),
+	BPF_ALU32_IMM(BPF_MOD, BPF_REG_1, 0x800000ff),
+
+	BPF_MOV32_IMM(BPF_REG_0, 0x80000000),
+	BPF_ALU32_IMM(BPF_ADD, BPF_REG_0, 1),
+	/* r1 signed 32-bit range is [S32_MIN, S32_MAX] */
+	BPF_JMP32_REG(BPF_JSLT, BPF_REG_0, BPF_REG_1, -2),
+
+	BPF_MOV64_IMM(BPF_REG_0, 0),
+	BPF_EXIT_INSN(),
+	},
+	.errstr = "BPF program is too large.",
+	.result = REJECT,
+	.prog_type = BPF_PROG_TYPE_XDP,
+},
-- 
2.30.2