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    SubjectRe: [bpf-next v3 11/12] selftests/bpf: Add tests for bpf_prog_test_run for perf events progs
    On Mon, Jul 8, 2019 at 3:42 PM Krzesimir Nowak <krzesimir@kinvolk.io> wrote:
    >
    > The tests check if ctx and data are correctly prepared from ctx_in and
    > data_in, so accessing the ctx and using the bpf_perf_prog_read_value
    > work as expected.
    >

    These are x86_64-specific tests, aren't they? Should probably guard
    them behind #ifdef's.

    > Signed-off-by: Krzesimir Nowak <krzesimir@kinvolk.io>
    > ---
    > tools/testing/selftests/bpf/test_verifier.c | 48 ++++++++++
    > .../selftests/bpf/verifier/perf_event_run.c | 96 +++++++++++++++++++
    > 2 files changed, 144 insertions(+)
    > create mode 100644 tools/testing/selftests/bpf/verifier/perf_event_run.c
    >
    > diff --git a/tools/testing/selftests/bpf/test_verifier.c b/tools/testing/selftests/bpf/test_verifier.c
    > index 6f124cc4ee34..484ea8842b06 100644
    > --- a/tools/testing/selftests/bpf/test_verifier.c
    > +++ b/tools/testing/selftests/bpf/test_verifier.c
    > @@ -295,6 +295,54 @@ static void bpf_fill_scale(struct bpf_test *self)
    > }
    > }
    >
    > +static void bpf_fill_perf_event_test_run_check(struct bpf_test *self)
    > +{
    > + compiletime_assert(
    > + sizeof(struct bpf_perf_event_data) <= TEST_CTX_LEN,
    > + "buffer for ctx is too short to fit struct bpf_perf_event_data");
    > + compiletime_assert(
    > + sizeof(struct bpf_perf_event_value) <= TEST_DATA_LEN,
    > + "buffer for data is too short to fit struct bpf_perf_event_value");
    > +
    > + struct bpf_perf_event_data ctx = {
    > + .regs = (bpf_user_pt_regs_t) {
    > + .r15 = 1,
    > + .r14 = 2,
    > + .r13 = 3,
    > + .r12 = 4,
    > + .rbp = 5,
    > + .rbx = 6,
    > + .r11 = 7,
    > + .r10 = 8,
    > + .r9 = 9,
    > + .r8 = 10,
    > + .rax = 11,
    > + .rcx = 12,
    > + .rdx = 13,
    > + .rsi = 14,
    > + .rdi = 15,
    > + .orig_rax = 16,
    > + .rip = 17,
    > + .cs = 18,
    > + .eflags = 19,
    > + .rsp = 20,
    > + .ss = 21,
    > + },
    > + .sample_period = 1,
    > + .addr = 2,
    > + };
    > + struct bpf_perf_event_value data = {
    > + .counter = 1,
    > + .enabled = 2,
    > + .running = 3,
    > + };
    > +
    > + memcpy(self->ctx, &ctx, sizeof(ctx));
    > + memcpy(self->data, &data, sizeof(data));

    Just curious, just assignment didn't work?

    > + free(self->fill_insns);
    > + self->fill_insns = NULL;
    > +}
    > +
    > /* BPF_SK_LOOKUP contains 13 instructions, if you need to fix up maps */
    > #define BPF_SK_LOOKUP(func) \
    > /* struct bpf_sock_tuple tuple = {} */ \
    > diff --git a/tools/testing/selftests/bpf/verifier/perf_event_run.c b/tools/testing/selftests/bpf/verifier/perf_event_run.c
    > new file mode 100644
    > index 000000000000..3f877458a7f8
    > --- /dev/null
    > +++ b/tools/testing/selftests/bpf/verifier/perf_event_run.c
    > @@ -0,0 +1,96 @@
    > +#define PER_LOAD_AND_CHECK_PTREG(PT_REG_FIELD, VALUE) \
    > + PER_LOAD_AND_CHECK_CTX(offsetof(bpf_user_pt_regs_t, PT_REG_FIELD), VALUE)
    > +#define PER_LOAD_AND_CHECK_EVENT(PED_FIELD, VALUE) \
    > + PER_LOAD_AND_CHECK_CTX(offsetof(struct bpf_perf_event_data, PED_FIELD), VALUE)
    > +#define PER_LOAD_AND_CHECK_CTX(OFFSET, VALUE) \
    > + PER_LOAD_AND_CHECK_64(BPF_REG_4, BPF_REG_1, OFFSET, VALUE)
    > +#define PER_LOAD_AND_CHECK_VALUE(PEV_FIELD, VALUE) \
    > + PER_LOAD_AND_CHECK_64(BPF_REG_7, BPF_REG_6, offsetof(struct bpf_perf_event_value, PEV_FIELD), VALUE)

    Wrap long lines? Try also running scripts/checkpatch.pl again these
    files you are modifying.

    > +#define PER_LOAD_AND_CHECK_64(DST, SRC, OFFSET, VALUE) \
    > + BPF_LDX_MEM(BPF_DW, DST, SRC, OFFSET), \
    > + BPF_JMP_IMM(BPF_JEQ, DST, VALUE, 2), \
    > + BPF_MOV64_IMM(BPF_REG_0, VALUE), \
    > + BPF_EXIT_INSN()
    > +
    > +{
    > + "check if regs contain expected values",
    > + .insns = {
    > + PER_LOAD_AND_CHECK_PTREG(r15, 1),
    > + PER_LOAD_AND_CHECK_PTREG(r14, 2),
    > + PER_LOAD_AND_CHECK_PTREG(r13, 3),
    > + PER_LOAD_AND_CHECK_PTREG(r12, 4),
    > + PER_LOAD_AND_CHECK_PTREG(rbp, 5),
    > + PER_LOAD_AND_CHECK_PTREG(rbx, 6),
    > + PER_LOAD_AND_CHECK_PTREG(r11, 7),
    > + PER_LOAD_AND_CHECK_PTREG(r10, 8),
    > + PER_LOAD_AND_CHECK_PTREG(r9, 9),
    > + PER_LOAD_AND_CHECK_PTREG(r8, 10),
    > + PER_LOAD_AND_CHECK_PTREG(rax, 11),
    > + PER_LOAD_AND_CHECK_PTREG(rcx, 12),
    > + PER_LOAD_AND_CHECK_PTREG(rdx, 13),
    > + PER_LOAD_AND_CHECK_PTREG(rsi, 14),
    > + PER_LOAD_AND_CHECK_PTREG(rdi, 15),
    > + PER_LOAD_AND_CHECK_PTREG(orig_rax, 16),
    > + PER_LOAD_AND_CHECK_PTREG(rip, 17),
    > + PER_LOAD_AND_CHECK_PTREG(cs, 18),
    > + PER_LOAD_AND_CHECK_PTREG(eflags, 19),
    > + PER_LOAD_AND_CHECK_PTREG(rsp, 20),
    > + PER_LOAD_AND_CHECK_PTREG(ss, 21),
    > + BPF_MOV64_IMM(BPF_REG_0, 0),
    > + BPF_EXIT_INSN(),
    > + },
    > + .result = ACCEPT,
    > + .prog_type = BPF_PROG_TYPE_PERF_EVENT,
    > + .ctx_len = sizeof(struct bpf_perf_event_data),
    > + .data_len = sizeof(struct bpf_perf_event_value),
    > + .fill_helper = bpf_fill_perf_event_test_run_check,
    > + .override_data_out_len = true,
    > +},
    > +{
    > + "check if sample period and addr contain expected values",
    > + .insns = {
    > + PER_LOAD_AND_CHECK_EVENT(sample_period, 1),
    > + PER_LOAD_AND_CHECK_EVENT(addr, 2),
    > + BPF_MOV64_IMM(BPF_REG_0, 0),
    > + BPF_EXIT_INSN(),
    > + },
    > + .result = ACCEPT,
    > + .prog_type = BPF_PROG_TYPE_PERF_EVENT,
    > + .ctx_len = sizeof(struct bpf_perf_event_data),
    > + .data_len = sizeof(struct bpf_perf_event_value),
    > + .fill_helper = bpf_fill_perf_event_test_run_check,
    > + .override_data_out_len = true,
    > +},
    > +{
    > + "check if bpf_perf_prog_read_value returns expected data",
    > + .insns = {
    > + // allocate space for a struct bpf_perf_event_value
    > + BPF_MOV64_REG(BPF_REG_6, BPF_REG_10),
    > + BPF_ALU64_IMM(BPF_ADD, BPF_REG_6, -(int)sizeof(struct bpf_perf_event_value)),
    > + // prepare parameters for bpf_perf_prog_read_value(ctx, struct bpf_perf_event_value*, u32)
    > + // BPF_REG_1 already contains the context
    > + BPF_MOV64_REG(BPF_REG_2, BPF_REG_6),
    > + BPF_MOV64_IMM(BPF_REG_3, sizeof(struct bpf_perf_event_value)),
    > + BPF_EMIT_CALL(BPF_FUNC_perf_prog_read_value),
    > + // check the return value
    > + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 1),
    > + BPF_EXIT_INSN(),
    > + // check if the fields match the expected values

    Use /* */ comments.

    > + PER_LOAD_AND_CHECK_VALUE(counter, 1),
    > + PER_LOAD_AND_CHECK_VALUE(enabled, 2),
    > + PER_LOAD_AND_CHECK_VALUE(running, 3),
    > + BPF_MOV64_IMM(BPF_REG_0, 0),
    > + BPF_EXIT_INSN(),
    > + },
    > + .result = ACCEPT,
    > + .prog_type = BPF_PROG_TYPE_PERF_EVENT,
    > + .ctx_len = sizeof(struct bpf_perf_event_data),
    > + .data_len = sizeof(struct bpf_perf_event_value),
    > + .fill_helper = bpf_fill_perf_event_test_run_check,
    > + .override_data_out_len = true,
    > +},
    > +#undef PER_LOAD_AND_CHECK_64
    > +#undef PER_LOAD_AND_CHECK_VALUE
    > +#undef PER_LOAD_AND_CHECK_CTX
    > +#undef PER_LOAD_AND_CHECK_EVENT
    > +#undef PER_LOAD_AND_CHECK_PTREG
    > --
    > 2.20.1
    >

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