samples: bpf: add a verifier test and summary line

- add a test specifically targeting verifier state pruning.
It checks state propagation between registers, storing that
state into stack and state pruning algorithm recognizing
equivalent stack and register states.

- add summary line to spot failures easier

Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/samples/bpf/test_verifier.c b/samples/bpf/test_verifier.c
index eb4bec0..6340274 100644 (file)
--- a/samples/bpf/test_verifier.c
+++ b/samples/bpf/test_verifier.c
@@ -602,6 +602,45 @@ static struct bpf_test tests[] = {
                },
                .result = ACCEPT,
        },
+       {
+               "jump test 5",
+               .insns = {
+                       BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
+                       BPF_MOV64_REG(BPF_REG_3, BPF_REG_2),
+                       BPF_JMP_IMM(BPF_JGE, BPF_REG_1, 0, 2),
+                       BPF_STX_MEM(BPF_DW, BPF_REG_2, BPF_REG_3, -8),
+                       BPF_JMP_IMM(BPF_JA, 0, 0, 2),
+                       BPF_STX_MEM(BPF_DW, BPF_REG_2, BPF_REG_2, -8),
+                       BPF_JMP_IMM(BPF_JA, 0, 0, 0),
+                       BPF_MOV64_IMM(BPF_REG_0, 0),
+                       BPF_JMP_IMM(BPF_JGE, BPF_REG_1, 0, 2),
+                       BPF_STX_MEM(BPF_DW, BPF_REG_2, BPF_REG_3, -8),
+                       BPF_JMP_IMM(BPF_JA, 0, 0, 2),
+                       BPF_STX_MEM(BPF_DW, BPF_REG_2, BPF_REG_2, -8),
+                       BPF_JMP_IMM(BPF_JA, 0, 0, 0),
+                       BPF_MOV64_IMM(BPF_REG_0, 0),
+                       BPF_JMP_IMM(BPF_JGE, BPF_REG_1, 0, 2),
+                       BPF_STX_MEM(BPF_DW, BPF_REG_2, BPF_REG_3, -8),
+                       BPF_JMP_IMM(BPF_JA, 0, 0, 2),
+                       BPF_STX_MEM(BPF_DW, BPF_REG_2, BPF_REG_2, -8),
+                       BPF_JMP_IMM(BPF_JA, 0, 0, 0),
+                       BPF_MOV64_IMM(BPF_REG_0, 0),
+                       BPF_JMP_IMM(BPF_JGE, BPF_REG_1, 0, 2),
+                       BPF_STX_MEM(BPF_DW, BPF_REG_2, BPF_REG_3, -8),
+                       BPF_JMP_IMM(BPF_JA, 0, 0, 2),
+                       BPF_STX_MEM(BPF_DW, BPF_REG_2, BPF_REG_2, -8),
+                       BPF_JMP_IMM(BPF_JA, 0, 0, 0),
+                       BPF_MOV64_IMM(BPF_REG_0, 0),
+                       BPF_JMP_IMM(BPF_JGE, BPF_REG_1, 0, 2),
+                       BPF_STX_MEM(BPF_DW, BPF_REG_2, BPF_REG_3, -8),
+                       BPF_JMP_IMM(BPF_JA, 0, 0, 2),
+                       BPF_STX_MEM(BPF_DW, BPF_REG_2, BPF_REG_2, -8),
+                       BPF_JMP_IMM(BPF_JA, 0, 0, 0),
+                       BPF_MOV64_IMM(BPF_REG_0, 0),
+                       BPF_EXIT_INSN(),
+               },
+               .result = ACCEPT,
+       },
 };
 
 static int probe_filter_length(struct bpf_insn *fp)
@@ -630,7 +669,7 @@ static int create_map(void)
 
 static int test(void)
 {
-       int prog_fd, i;
+       int prog_fd, i, pass_cnt = 0, err_cnt = 0;
 
        for (i = 0; i < ARRAY_SIZE(tests); i++) {
                struct bpf_insn *prog = tests[i].insns;
@@ -657,21 +696,25 @@ static int test(void)
                                printf("FAIL\nfailed to load prog '%s'\n",
                                       strerror(errno));
                                printf("%s", bpf_log_buf);
+                               err_cnt++;
                                goto fail;
                        }
                } else {
                        if (prog_fd >= 0) {
                                printf("FAIL\nunexpected success to load\n");
                                printf("%s", bpf_log_buf);
+                               err_cnt++;
                                goto fail;
                        }
                        if (strstr(bpf_log_buf, tests[i].errstr) == 0) {
                                printf("FAIL\nunexpected error message: %s",
                                       bpf_log_buf);
+                               err_cnt++;
                                goto fail;
                        }
                }
 
+               pass_cnt++;
                printf("OK\n");
 fail:
                if (map_fd >= 0)
@@ -679,6 +722,7 @@ fail:
                close(prog_fd);
 
        }
+       printf("Summary: %d PASSED, %d FAILED\n", pass_cnt, err_cnt);
 
        return 0;
 }