Add a test to verify global percpu data related xlated insns: 1. ld_imm64: compare xlated one with the one in ELF object file. 2. mov64_percpu_reg: it is added by verifier.
Signed-off-by: Leon Hwang <[email protected]> --- .../bpf/prog_tests/global_data_init.c | 86 +++++++++++++++++++ .../bpf/progs/test_global_percpu_data.c | 11 +++ 2 files changed, 97 insertions(+) diff --git a/tools/testing/selftests/bpf/prog_tests/global_data_init.c b/tools/testing/selftests/bpf/prog_tests/global_data_init.c index 729878d5d3b3..c3b9423246b5 100644 --- a/tools/testing/selftests/bpf/prog_tests/global_data_init.c +++ b/tools/testing/selftests/bpf/prog_tests/global_data_init.c @@ -249,6 +249,90 @@ static void test_global_percpu_data_verifier_log(void) RUN_TESTS(test_global_percpu_data); } +static int find_ld_imm64(const struct bpf_insn *insns, size_t insn_cnt, struct bpf_insn *ld_imm64) +{ + size_t i; + + for (i = 0; i < insn_cnt; i++) { + if (insns[i].code == (BPF_LD | BPF_IMM | BPF_DW)) { + ld_imm64[0] = insns[i]; + ld_imm64[1] = insns[i + 1]; + return i; + } + } + + return -ENOENT; +} + +/* + * Special (internal-only) form of mov, used to resolve per-CPU addrs: + * dst_reg = src_reg + <percpu_base_off> + * BPF_ADDR_PERCPU is used as a special insn->off value. + */ +#define BPF_ADDR_PERCPU (-1) + +#define BPF_MOV64_PERCPU_REG(DST, SRC) \ + ((struct bpf_insn) { \ + .code = BPF_ALU64 | BPF_MOV | BPF_X, \ + .dst_reg = DST, \ + .src_reg = SRC, \ + .off = BPF_ADDR_PERCPU, \ + .imm = 0 }) + +static __u64 ld_imm64_to_u64(const struct bpf_insn *insn) +{ + return ((__u64) insn[1].imm << 32) | (__u64) insn[0].imm; +} + +static void test_global_percpu_data_xlated(void) +{ + struct bpf_insn ld_imm64_raw[2], ld_imm64_xlated[2], mov64_percpu_reg, *insns = NULL; + size_t insn_sz = sizeof(struct bpf_insn); + struct test_global_percpu_data *skel; + struct bpf_program *prog; + int idx, err; + __u32 cnt; + + skel = test_global_percpu_data__open(); + if (!ASSERT_OK_PTR(skel, "test_global_percpu_data__open")) + return; + + prog = skel->progs.verifier_percpu_read; + idx = find_ld_imm64(bpf_program__insns(prog), bpf_program__insn_cnt(prog), ld_imm64_raw); + if (!ASSERT_GE(idx, 0, "find_ld_imm64 raw")) + goto out; + + err = test_global_percpu_data__load(skel); + if (!ASSERT_OK(err, "test_global_percpu_data__load")) + goto out; + + err = get_xlated_program(bpf_program__fd(prog), &insns, &cnt); + if (!ASSERT_OK(err, "get_xlated_program")) + goto out; + if (!ASSERT_GT(cnt, idx + 2, "xlated insn count")) + goto out; + + idx = find_ld_imm64(insns, cnt, ld_imm64_xlated); + if (!ASSERT_GE(idx, 0, "find_ld_imm64 xlated")) + goto out; + + ASSERT_EQ(ld_imm64_xlated[0].code, ld_imm64_raw[0].code, "ld_imm64 opcode"); + ASSERT_TRUE(ld_imm64_xlated[0].dst_reg == ld_imm64_raw[0].dst_reg, "ld_imm64 dst_reg"); + /* + * The xlated instruction has the map ID in imm and the offset + * in the next instruction's imm. The raw instruction just has + * the offset in its imm. + */ + ASSERT_EQ(ld_imm64_xlated[1].imm, ld_imm64_to_u64(ld_imm64_raw), "ld_imm64 off"); + + mov64_percpu_reg = BPF_MOV64_PERCPU_REG(ld_imm64_raw[0].dst_reg, ld_imm64_raw[0].dst_reg); + ASSERT_MEMEQ(&insns[idx + 2], &mov64_percpu_reg, insn_sz, "mov64_percpu_reg"); + +out: + test_global_percpu_data__destroy(skel); + free(insns); +} + void test_global_percpu_data(void) { if (!feat_supported(NULL, FEAT_PERCPU_DATA)) { @@ -262,4 +346,6 @@ void test_global_percpu_data(void) test_global_percpu_data_lskel(); if (test__start_subtest("verifier_log")) test_global_percpu_data_verifier_log(); + if (test__start_subtest("xlated")) + test_global_percpu_data_xlated(); } diff --git a/tools/testing/selftests/bpf/progs/test_global_percpu_data.c b/tools/testing/selftests/bpf/progs/test_global_percpu_data.c index 2222ad3a49bd..9a1b1a314c2f 100644 --- a/tools/testing/selftests/bpf/progs/test_global_percpu_data.c +++ b/tools/testing/selftests/bpf/progs/test_global_percpu_data.c @@ -51,4 +51,15 @@ int verifier_snprintf(void *ctx) return 0; } +static volatile const char fmt2[] SEC(".percpu.fmt") = "data %d\n"; + +SEC("kprobe") +__auxiliary +int verifier_percpu_read(void *ctx) +{ + char c = fmt2[4]; + + return c == ' '; +} + char _license[] SEC("license") = "GPL"; -- 2.54.0
