selftests/bpf: Add selftests for bpf_perf_event_output

Software event output is only enabled by a few prog types.
This test is to ensure that all supported types are enabled for
bpf_perf_event_output successfully.

Signed-off-by: Allan Zhang <allanzhang@google.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

diff --git a/tools/testing/selftests/bpf/test_verifier.c b/tools/testing/selftests/bpf/test_verifier.c
index 84135d5f4b351043a212c9c2c24bde4fb0e04418..44e2d640b088ca10668d28e3a1c3b6acae8ec194 100644 (file)
--- a/tools/testing/selftests/bpf/test_verifier.c
+++ b/tools/testing/selftests/bpf/test_verifier.c
@@ -50,7 +50,7 @@
 #define MAX_INSNS      BPF_MAXINSNS
 #define MAX_TEST_INSNS 1000000
 #define MAX_FIXUPS     8
-#define MAX_NR_MAPS    18
+#define MAX_NR_MAPS    19
 #define MAX_TEST_RUNS  8
 #define POINTER_VALUE  0xcafe4all
 #define TEST_DATA_LEN  64
@@ -84,6 +84,7 @@ struct bpf_test {
        int fixup_map_array_wo[MAX_FIXUPS];
        int fixup_map_array_small[MAX_FIXUPS];
        int fixup_sk_storage_map[MAX_FIXUPS];
+       int fixup_map_event_output[MAX_FIXUPS];
        const char *errstr;
        const char *errstr_unpriv;
        uint32_t insn_processed;
@@ -632,6 +633,7 @@ static void do_test_fixup(struct bpf_test *test, enum bpf_prog_type prog_type,
        int *fixup_map_array_wo = test->fixup_map_array_wo;
        int *fixup_map_array_small = test->fixup_map_array_small;
        int *fixup_sk_storage_map = test->fixup_sk_storage_map;
+       int *fixup_map_event_output = test->fixup_map_event_output;
 
        if (test->fill_helper) {
                test->fill_insns = calloc(MAX_TEST_INSNS, sizeof(struct bpf_insn));
@@ -793,6 +795,14 @@ static void do_test_fixup(struct bpf_test *test, enum bpf_prog_type prog_type,
                        fixup_sk_storage_map++;
                } while (*fixup_sk_storage_map);
        }
+       if (*fixup_map_event_output) {
+               map_fds[18] = __create_map(BPF_MAP_TYPE_PERF_EVENT_ARRAY,
+                                          sizeof(int), sizeof(int), 1, 0);
+               do {
+                       prog[*fixup_map_event_output].imm = map_fds[18];
+                       fixup_map_event_output++;
+               } while (*fixup_map_event_output);
+       }
 }
 
 static int set_admin(bool admin)

diff --git a/tools/testing/selftests/bpf/verifier/event_output.c b/tools/testing/selftests/bpf/verifier/event_output.c
new file mode 100644 (file)
index 0000000..130553e
--- /dev/null
+++ b/tools/testing/selftests/bpf/verifier/event_output.c
@@ -0,0 +1,94 @@
+/* instructions used to output a skb based software event, produced
+ * from code snippet:
+ * struct TMP {
+ *  uint64_t tmp;
+ * } tt;
+ * tt.tmp = 5;
+ * bpf_perf_event_output(skb, &connection_tracking_event_map, 0,
+ *                      &tt, sizeof(tt));
+ * return 1;
+ *
+ * the bpf assembly from llvm is:
+ *        0:       b7 02 00 00 05 00 00 00         r2 = 5
+ *        1:       7b 2a f8 ff 00 00 00 00         *(u64 *)(r10 - 8) = r2
+ *        2:       bf a4 00 00 00 00 00 00         r4 = r10
+ *        3:       07 04 00 00 f8 ff ff ff         r4 += -8
+ *        4:       18 02 00 00 00 00 00 00 00 00 00 00 00 00 00 00    r2 = 0ll
+ *        6:       b7 03 00 00 00 00 00 00         r3 = 0
+ *        7:       b7 05 00 00 08 00 00 00         r5 = 8
+ *        8:       85 00 00 00 19 00 00 00         call 25
+ *        9:       b7 00 00 00 01 00 00 00         r0 = 1
+ *       10:       95 00 00 00 00 00 00 00         exit
+ *
+ *     The reason I put the code here instead of fill_helpers is that map fixup
+ *     is against the insns, instead of filled prog.
+ */
+
+#define __PERF_EVENT_INSNS__                                   \
+       BPF_MOV64_IMM(BPF_REG_2, 5),                            \
+       BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_2, -8),         \
+       BPF_MOV64_REG(BPF_REG_4, BPF_REG_10),                   \
+       BPF_ALU64_IMM(BPF_ADD, BPF_REG_4, -8),                  \
+       BPF_LD_MAP_FD(BPF_REG_2, 0),                            \
+       BPF_MOV64_IMM(BPF_REG_3, 0),                            \
+       BPF_MOV64_IMM(BPF_REG_5, 8),                            \
+       BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,               \
+                    BPF_FUNC_perf_event_output),               \
+       BPF_MOV64_IMM(BPF_REG_0, 1),                            \
+       BPF_EXIT_INSN(),
+{
+       "perfevent for sockops",
+       .insns = { __PERF_EVENT_INSNS__ },
+       .prog_type = BPF_PROG_TYPE_SOCK_OPS,
+       .fixup_map_event_output = { 4 },
+       .result = ACCEPT,
+       .retval = 1,
+},
+{
+       "perfevent for tc",
+       .insns =  { __PERF_EVENT_INSNS__ },
+       .prog_type = BPF_PROG_TYPE_SCHED_CLS,
+       .fixup_map_event_output = { 4 },
+       .result = ACCEPT,
+       .retval = 1,
+},
+{
+       "perfevent for lwt out",
+       .insns =  { __PERF_EVENT_INSNS__ },
+       .prog_type = BPF_PROG_TYPE_LWT_OUT,
+       .fixup_map_event_output = { 4 },
+       .result = ACCEPT,
+       .retval = 1,
+},
+{
+       "perfevent for xdp",
+       .insns =  { __PERF_EVENT_INSNS__ },
+       .prog_type = BPF_PROG_TYPE_XDP,
+       .fixup_map_event_output = { 4 },
+       .result = ACCEPT,
+       .retval = 1,
+},
+{
+       "perfevent for socket filter",
+       .insns =  { __PERF_EVENT_INSNS__ },
+       .prog_type = BPF_PROG_TYPE_SOCKET_FILTER,
+       .fixup_map_event_output = { 4 },
+       .result = ACCEPT,
+       .retval = 1,
+},
+{
+       "perfevent for sk_skb",
+       .insns =  { __PERF_EVENT_INSNS__ },
+       .prog_type = BPF_PROG_TYPE_SK_SKB,
+       .fixup_map_event_output = { 4 },
+       .result = ACCEPT,
+       .retval = 1,
+},
+{
+       "perfevent for cgroup skb",
+       .insns =  { __PERF_EVENT_INSNS__ },
+       .prog_type = BPF_PROG_TYPE_CGROUP_SKB,
+       .fixup_map_event_output = { 4 },
+       .result = ACCEPT,
+       .retval = 1,
+},