From: Eduard Zingerman <eddyz87@gmail.com>
To: bpf@vger.kernel.org, ast@kernel.org, andrii@kernel.org,
daniel@iogearbox.net, kernel-team@fb.com, song@kernel.org,
joannelkoong@gmail.com
Cc: eddyz87@gmail.com, Song Liu <songliubraving@fb.com>
Subject: [PATCH bpf-next v7 4/5] selftests/bpf: BPF test_verifier selftests for bpf_loop inlining
Date: Mon, 13 Jun 2022 23:50:07 +0300 [thread overview]
Message-ID: <20220613205008.212724-5-eddyz87@gmail.com> (raw)
In-Reply-To: <20220613205008.212724-1-eddyz87@gmail.com>
A number of test cases for BPF selftests test_verifier to check how
bpf_loop inline transformation rewrites the BPF program. The following
cases are covered:
- happy path
- no-rewrite when flags is non-zero
- no-rewrite when callback is non-constant
- subprogno in insn_aux is updated correctly when dead sub-programs
are removed
- check that correct stack offsets are assigned for spilling of R6-R8
registers
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Acked-by: Song Liu <songliubraving@fb.com>
---
.../selftests/bpf/verifier/bpf_loop_inline.c | 244 ++++++++++++++++++
1 file changed, 244 insertions(+)
create mode 100644 tools/testing/selftests/bpf/verifier/bpf_loop_inline.c
diff --git a/tools/testing/selftests/bpf/verifier/bpf_loop_inline.c b/tools/testing/selftests/bpf/verifier/bpf_loop_inline.c
new file mode 100644
index 000000000000..d1fbcfef69f2
--- /dev/null
+++ b/tools/testing/selftests/bpf/verifier/bpf_loop_inline.c
@@ -0,0 +1,244 @@
+#define BTF_TYPES \
+ .btf_strings = "\0int\0i\0ctx\0callback\0main\0", \
+ .btf_types = { \
+ /* 1: int */ BTF_TYPE_INT_ENC(1, BTF_INT_SIGNED, 0, 32, 4), \
+ /* 2: int* */ BTF_PTR_ENC(1), \
+ /* 3: void* */ BTF_PTR_ENC(0), \
+ /* 4: int __(void*) */ BTF_FUNC_PROTO_ENC(1, 1), \
+ BTF_FUNC_PROTO_ARG_ENC(7, 3), \
+ /* 5: int __(int, int*) */ BTF_FUNC_PROTO_ENC(1, 2), \
+ BTF_FUNC_PROTO_ARG_ENC(5, 1), \
+ BTF_FUNC_PROTO_ARG_ENC(7, 2), \
+ /* 6: main */ BTF_FUNC_ENC(20, 4), \
+ /* 7: callback */ BTF_FUNC_ENC(11, 5), \
+ BTF_END_RAW \
+ }
+
+#define MAIN_TYPE 6
+#define CALLBACK_TYPE 7
+
+/* can't use BPF_CALL_REL, jit_subprogs adjusts IMM & OFF
+ * fields for pseudo calls
+ */
+#define PSEUDO_CALL_INSN() \
+ BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, BPF_PSEUDO_CALL, \
+ INSN_OFF_MASK, INSN_IMM_MASK)
+
+/* can't use BPF_FUNC_loop constant,
+ * do_mix_fixups adjusts the IMM field
+ */
+#define HELPER_CALL_INSN() \
+ BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, INSN_OFF_MASK, INSN_IMM_MASK)
+
+{
+ "inline simple bpf_loop call",
+ .insns = {
+ /* main */
+ /* force verifier state branching to verify logic on first and
+ * subsequent bpf_loop insn processing steps
+ */
+ BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_jiffies64),
+ BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 777, 2),
+ BPF_ALU64_IMM(BPF_MOV, BPF_REG_1, 1),
+ BPF_JMP_IMM(BPF_JA, 0, 0, 1),
+ BPF_ALU64_IMM(BPF_MOV, BPF_REG_1, 2),
+
+ BPF_RAW_INSN(BPF_LD | BPF_IMM | BPF_DW, BPF_REG_2, BPF_PSEUDO_FUNC, 0, 6),
+ BPF_RAW_INSN(0, 0, 0, 0, 0),
+ BPF_ALU64_IMM(BPF_MOV, BPF_REG_3, 0),
+ BPF_ALU64_IMM(BPF_MOV, BPF_REG_4, 0),
+ BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_loop),
+ BPF_ALU64_IMM(BPF_MOV, BPF_REG_0, 0),
+ BPF_EXIT_INSN(),
+ /* callback */
+ BPF_ALU64_IMM(BPF_MOV, BPF_REG_0, 1),
+ BPF_EXIT_INSN(),
+ },
+ .expected_insns = { PSEUDO_CALL_INSN() },
+ .unexpected_insns = { HELPER_CALL_INSN() },
+ .prog_type = BPF_PROG_TYPE_TRACEPOINT,
+ .result = ACCEPT,
+ .runs = 0,
+ .func_info = { { 0, MAIN_TYPE }, { 12, CALLBACK_TYPE } },
+ .func_info_cnt = 2,
+ BTF_TYPES
+},
+{
+ "don't inline bpf_loop call, flags non-zero",
+ .insns = {
+ /* main */
+ BPF_ALU64_IMM(BPF_MOV, BPF_REG_1, 1),
+ BPF_RAW_INSN(BPF_LD | BPF_IMM | BPF_DW, BPF_REG_2, BPF_PSEUDO_FUNC, 0, 6),
+ BPF_RAW_INSN(0, 0, 0, 0, 0),
+ BPF_ALU64_IMM(BPF_MOV, BPF_REG_3, 0),
+ BPF_ALU64_IMM(BPF_MOV, BPF_REG_4, 1),
+ BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_loop),
+ BPF_ALU64_IMM(BPF_MOV, BPF_REG_0, 0),
+ BPF_EXIT_INSN(),
+ /* callback */
+ BPF_ALU64_IMM(BPF_MOV, BPF_REG_0, 1),
+ BPF_EXIT_INSN(),
+ },
+ .expected_insns = { HELPER_CALL_INSN() },
+ .unexpected_insns = { PSEUDO_CALL_INSN() },
+ .prog_type = BPF_PROG_TYPE_TRACEPOINT,
+ .result = ACCEPT,
+ .runs = 0,
+ .func_info = { { 0, MAIN_TYPE }, { 8, CALLBACK_TYPE } },
+ .func_info_cnt = 2,
+ BTF_TYPES
+},
+{
+ "don't inline bpf_loop call, callback non-constant",
+ .insns = {
+ /* main */
+ BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_jiffies64),
+ BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 777, 4), /* pick a random callback */
+
+ BPF_ALU64_IMM(BPF_MOV, BPF_REG_1, 1),
+ BPF_RAW_INSN(BPF_LD | BPF_IMM | BPF_DW, BPF_REG_2, BPF_PSEUDO_FUNC, 0, 10),
+ BPF_RAW_INSN(0, 0, 0, 0, 0),
+ BPF_JMP_IMM(BPF_JA, 0, 0, 3),
+
+ BPF_ALU64_IMM(BPF_MOV, BPF_REG_1, 1),
+ BPF_RAW_INSN(BPF_LD | BPF_IMM | BPF_DW, BPF_REG_2, BPF_PSEUDO_FUNC, 0, 8),
+ BPF_RAW_INSN(0, 0, 0, 0, 0),
+
+ BPF_ALU64_IMM(BPF_MOV, BPF_REG_3, 0),
+ BPF_ALU64_IMM(BPF_MOV, BPF_REG_4, 0),
+ BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_loop),
+ BPF_ALU64_IMM(BPF_MOV, BPF_REG_0, 0),
+ BPF_EXIT_INSN(),
+ /* callback */
+ BPF_ALU64_IMM(BPF_MOV, BPF_REG_0, 1),
+ BPF_EXIT_INSN(),
+ /* callback #2 */
+ BPF_ALU64_IMM(BPF_MOV, BPF_REG_0, 1),
+ BPF_EXIT_INSN(),
+ },
+ .expected_insns = { HELPER_CALL_INSN() },
+ .unexpected_insns = { PSEUDO_CALL_INSN() },
+ .prog_type = BPF_PROG_TYPE_TRACEPOINT,
+ .result = ACCEPT,
+ .runs = 0,
+ .func_info = {
+ { 0, MAIN_TYPE },
+ { 14, CALLBACK_TYPE },
+ { 16, CALLBACK_TYPE }
+ },
+ .func_info_cnt = 3,
+ BTF_TYPES
+},
+{
+ "bpf_loop_inline and a dead func",
+ .insns = {
+ /* main */
+
+ /* A reference to callback #1 to make verifier count it as a func.
+ * This reference is overwritten below and callback #1 is dead.
+ */
+ BPF_RAW_INSN(BPF_LD | BPF_IMM | BPF_DW, BPF_REG_2, BPF_PSEUDO_FUNC, 0, 9),
+ BPF_RAW_INSN(0, 0, 0, 0, 0),
+ BPF_ALU64_IMM(BPF_MOV, BPF_REG_1, 1),
+ BPF_RAW_INSN(BPF_LD | BPF_IMM | BPF_DW, BPF_REG_2, BPF_PSEUDO_FUNC, 0, 8),
+ BPF_RAW_INSN(0, 0, 0, 0, 0),
+ BPF_ALU64_IMM(BPF_MOV, BPF_REG_3, 0),
+ BPF_ALU64_IMM(BPF_MOV, BPF_REG_4, 0),
+ BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_loop),
+ BPF_ALU64_IMM(BPF_MOV, BPF_REG_0, 0),
+ BPF_EXIT_INSN(),
+ /* callback */
+ BPF_ALU64_IMM(BPF_MOV, BPF_REG_0, 1),
+ BPF_EXIT_INSN(),
+ /* callback #2 */
+ BPF_ALU64_IMM(BPF_MOV, BPF_REG_0, 1),
+ BPF_EXIT_INSN(),
+ },
+ .expected_insns = { PSEUDO_CALL_INSN() },
+ .unexpected_insns = { HELPER_CALL_INSN() },
+ .prog_type = BPF_PROG_TYPE_TRACEPOINT,
+ .result = ACCEPT,
+ .runs = 0,
+ .func_info = {
+ { 0, MAIN_TYPE },
+ { 10, CALLBACK_TYPE },
+ { 12, CALLBACK_TYPE }
+ },
+ .func_info_cnt = 3,
+ BTF_TYPES
+},
+{
+ "bpf_loop_inline stack locations for loop vars",
+ .insns = {
+ /* main */
+ BPF_ST_MEM(BPF_DW, BPF_REG_10, -16, 0x77),
+ /* bpf_loop call #1 */
+ BPF_ALU64_IMM(BPF_MOV, BPF_REG_1, 1),
+ BPF_RAW_INSN(BPF_LD | BPF_IMM | BPF_DW, BPF_REG_2, BPF_PSEUDO_FUNC, 0, 22),
+ BPF_RAW_INSN(0, 0, 0, 0, 0),
+ BPF_ALU64_IMM(BPF_MOV, BPF_REG_3, 0),
+ BPF_ALU64_IMM(BPF_MOV, BPF_REG_4, 0),
+ BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_loop),
+ /* bpf_loop call #2 */
+ BPF_ALU64_IMM(BPF_MOV, BPF_REG_1, 2),
+ BPF_RAW_INSN(BPF_LD | BPF_IMM | BPF_DW, BPF_REG_2, BPF_PSEUDO_FUNC, 0, 16),
+ BPF_RAW_INSN(0, 0, 0, 0, 0),
+ BPF_ALU64_IMM(BPF_MOV, BPF_REG_3, 0),
+ BPF_ALU64_IMM(BPF_MOV, BPF_REG_4, 0),
+ BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_loop),
+ /* call func and exit */
+ BPF_CALL_REL(2),
+ BPF_ALU64_IMM(BPF_MOV, BPF_REG_0, 0),
+ BPF_EXIT_INSN(),
+ /* func */
+ BPF_ST_MEM(BPF_DW, BPF_REG_10, -32, 0x55),
+ BPF_ALU64_IMM(BPF_MOV, BPF_REG_1, 2),
+ BPF_RAW_INSN(BPF_LD | BPF_IMM | BPF_DW, BPF_REG_2, BPF_PSEUDO_FUNC, 0, 6),
+ BPF_RAW_INSN(0, 0, 0, 0, 0),
+ BPF_ALU64_IMM(BPF_MOV, BPF_REG_3, 0),
+ BPF_ALU64_IMM(BPF_MOV, BPF_REG_4, 0),
+ BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_loop),
+ BPF_ALU64_IMM(BPF_MOV, BPF_REG_0, 0),
+ BPF_EXIT_INSN(),
+ /* callback */
+ BPF_ALU64_IMM(BPF_MOV, BPF_REG_0, 1),
+ BPF_EXIT_INSN(),
+ },
+ .expected_insns = {
+ BPF_ST_MEM(BPF_DW, BPF_REG_10, -16, 0x77),
+ SKIP_INSNS(),
+ BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_6, -40),
+ BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_7, -32),
+ BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_8, -24),
+ SKIP_INSNS(),
+ /* offsets are the same as in the first call */
+ BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_6, -40),
+ BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_7, -32),
+ BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_8, -24),
+ SKIP_INSNS(),
+ BPF_ST_MEM(BPF_DW, BPF_REG_10, -32, 0x55),
+ SKIP_INSNS(),
+ /* offsets differ from main because of different offset
+ * in BPF_ST_MEM instruction
+ */
+ BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_6, -56),
+ BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_7, -48),
+ BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_8, -40),
+ },
+ .unexpected_insns = { HELPER_CALL_INSN() },
+ .prog_type = BPF_PROG_TYPE_TRACEPOINT,
+ .result = ACCEPT,
+ .func_info = {
+ { 0, MAIN_TYPE },
+ { 16, MAIN_TYPE },
+ { 25, CALLBACK_TYPE },
+ },
+ .func_info_cnt = 3,
+ BTF_TYPES
+},
+
+#undef HELPER_CALL_INSN
+#undef PSEUDO_CALL_INSN
+#undef CALLBACK_TYPE
+#undef MAIN_TYPE
+#undef BTF_TYPES
--
2.25.1
next prev parent reply other threads:[~2022-06-13 21:12 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-06-13 20:50 [PATCH bpf-next v7 0/5] bpf_loop inlining Eduard Zingerman
2022-06-13 20:50 ` [PATCH bpf-next v7 1/5] selftests/bpf: specify expected instructions in test_verifier tests Eduard Zingerman
2022-06-13 20:50 ` [PATCH bpf-next v7 2/5] selftests/bpf: allow BTF specs and func infos " Eduard Zingerman
2022-06-13 20:50 ` [PATCH bpf-next v7 3/5] bpf: Inline calls to bpf_loop when callback is known Eduard Zingerman
2022-06-14 5:49 ` Song Liu
2022-06-16 23:12 ` Daniel Borkmann
2022-06-17 2:14 ` Alexei Starovoitov
2022-06-19 20:09 ` Eduard Zingerman
2022-06-19 21:10 ` Alexei Starovoitov
2022-06-19 22:01 ` Eduard Zingerman
2022-06-19 23:37 ` Alexei Starovoitov
2022-06-20 12:59 ` Eduard Zingerman
2022-06-13 20:50 ` Eduard Zingerman [this message]
2022-06-13 20:50 ` [PATCH bpf-next v7 5/5] selftests/bpf: BPF test_prog selftests for bpf_loop inlining Eduard Zingerman
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